Anionic conductor

Abstract

The invention relates to an anion-conducting composite material, which comprises (a) a porous support material; and (b) a composition disposed on the porous support material, wherein the composition comprises: (i) a cationic polymer, and (ii) a reacted crosslinker, wherein the reacted crosslinker is obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer, wherein the crosslinker compound comprises n of said reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): (A), (B), (C), (D), wherein R1 is H or –S(O)2R2, and R2 is an unsubstituted or substituted C1-6 alkyl group or an unsubstituted or substituted aryl group. The invention also provides a process for producing an anion- conducting composite material. Also provided is the use of an anion-conducting composite material which is an anion-conducting membrane, as an anion exchange membrane. The invention also provides a polymer, and a process for producing a polymer network bound to one or more substrates.

Description

[0001] ANIONIC CONDUCTOR

[0002] FIELD OF THE INVENTION

[0003] The invention provides an anion-conducting composite material, and a process for producing an anion-conducting composite material. Also provided is the use of an anion-conducting composite material which is an anion-conducting membrane, as an anion exchange membrane. The invention also provides a polymer, and a process for producing a polymer network bound to one or more substrates.

[0004] BACKGROUND TO THE INVENTION

[0005] Anion-conducting materials have many uses in industry, including for instance as anion exchange membranes, electrolysers and as anion-conducting separators and fdters. Such membranes, separators and fdters must have good physical and chemical stability in order to maintain their structural integrity under conditions of use, maximise lifetime and resistance to degradation. Such conditions may include elevated temperatures, exposure to solvents (including water) that could cause the material to swell, and exposure to electrolysis systems at extreme pH.

[0006] Inert materials, such as unfunctionalised polymers, may provide such stability but are poor anion conductors. Materials that perform well as anion conductors, on the other hand, tend to have a high concentration of functional groups that facilitate anion conduction, which are typically cationic groups, throughout the bulk of their molecular structure. However, those functional groups render such materials susceptible to chemical attack, solvent swelling, dissolution in water and alkaline systems, and thermal degradation. This inherent instability adversely affects anion-conducting performance over time, reducing the useable lifetime of the materials. However, employing materials with a lower concentration of such functional groups detrimentally affects anion conduction performance.

[0007] Efforts to improve anion conduction in such materials without compromising on stability have thus far proved ineffective or prohibitively expensive. Common problems with existing systems include the poor stability of quaternary ammonium polymers when they are exposed to highly basic conditions, and the use of long and expensive manufacturing methods involving multiple synthesis phases, and / or expensive perfluorinated polymers, in attempts to improve stability. Existing composite anion exchange membranes typically suffer from poor adhesion between support material and resin when exposed to water (also referred to as washout), poor stability of quaternary ammonium polymer when exposed to highly basic conditions, poor mechanical properties, i.e. material flaking or crumbling due to weak bonding, and low conductivity.

[0008] There is therefore an ongoing need for improved anion-conducting materials, that can be produced at low cost and which have improved anionic conductivity and improved stability (and therefore increased durability in use) compared to the currently available materials. SUMMARY OF THE INVENTION

[0009] It is a finding of the invention that such improvements are provided by composite materials in which a composition or “resin” forms multiple anion-conducting pathways through a porous support material. The support provides physical strength and can be chemically inert, while the resin provides the desired anionic conductivity. The resin employs a cationic polymer with a high concentration of cationic groups, to facilitate the efficient conduction of mobile anions, in combination with a reacted crosslinker that binds the resin components together and to the porous support. The use of a crosslinker with multiple reactive head groups, which can covalently bind to a wide variety of materials via highly -reactive carbene or nitrene intermediate chemistry, ensures strength of binding between the anion conducting component(s) and the inert support. It crosslinks the cationic polymer to render it insoluble and highly stable, increasing the stability of the composition both physically and chemically. Advantageously, the composites can be produced at low cost and can provide the combined advantages of effective anionic conduction and physical and chemical stability, hence durability in use. The composites are also easily provided in membrane form, facilitating their use as anion exchange membranes and in other membrane applications.

[0010] Accordingly, the invention provides an anion-conducting composite material which comprises:

[0011] (a) a porous support material; and

[0012] (b) a composition disposed on the porous support material, wherein the composition comprises: (i) a cationic polymer, and (ii) a reacted crosslinker.

[0013] Typically, the reacted crosslinker is obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer. The crosslinker compound comprises n of said reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group.

[0014] The invention also provides a process for producing an anion-conducting composite material, which process comprises:

[0015] (a) contacting a porous support material with a cationic polymer and a crosslinker compound, wherein the crosslinker compound comprises n reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B), and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-e alkyl group or an unsubstituted or substituted aryl group; and

[0016] (b) generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0017] The invention further provides an anion-conducting composite material which is obtainable by the process of the invention.

[0018] The invention also provides the use of an anion-conducting composite material of the invention, which is an anion-conducting membrane, as an anion exchange membrane.

[0019] The invention also provides a polymer comprising repeat units of formula (X) wherein each E is a carbene precursor group selected from a hydrazone group of formula (A), a diazo group of formula (B), or a diazirine group of formula (C) wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group; and Lxis a spacer group.

[0020] The invention further provides a process for producing a polymer network bound to one or more substrates, which process comprises:

[0021] (a) contacting one or more substrates with a polymer of the invention; and

[0022] (b) generating carbene reactive intermediate groups from said carbene precursor groups, so that said carbene reactive intermediate groups react with the one or more substrates to produce said polymer network bound to the one or more substrates.

[0023] DETAILED DESCRIPTION OF THE INVENTION

[0024] Chemical definitions

[0025] As used herein, a C1-20 alkyl group is an unsubstituted or substituted, straight or branched chain saturated hydrocarbon radical having from 1 to 20 carbon atoms. Typically it is C1-10 alkyl, for example methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl, or C1-6 alkyl, for example methyl, ethyl, propyl, butyl, pentyl or hexyl, or C1.4 alkyl, for example methyl, ethyl, i- propyl, n-propyl, t-butyl, s-butyl or n-butyl. In one embodiment, it is a C2-20 alkyl group or, for instance, a C3-20 alkyl or a C4-20 alkyl group. When an alkyl group is substituted it typically bears one or more (e.g. one, two, three or four) substituents selected from substituted or unsubstituted C1-20 alkyl; substituted or unsubstituted C2-20 alkenyl; substituted or unsubstituted C2-20 alkynyl; substituted or unsubstituted aryl; substituted or unsubstituted aralkyl; halo; cyano; keto; amino; C1-10 alkylamino; di(Ci-io)alkylamino; arylamino; diarylamino; arylalkylamino; amido; acylamido; C1-20 haloalkyl (e.g. - CF3); ester; acyl; acyloxy; C1-10 alkoxy; aryloxy; nitro; hydroxyl, carboxy; sulfonic acid; sulfonyl; sulphonamide; sulfhydryl (i.e. thiol, -SH); Cn 10 alkylthio; arylthio; tri(Ci-2o alkyl)silyl; aryldi(Ci-2o alkyl)silyl; diaryl(Ci-2o alkyl)silyl; and triarylsilyl.

[0026] Examples of substituted alkyl groups include C1-20 haloalkyl, alkoxyalkyl and alkaryl groups. The term alkaryl, as used herein, pertains to a C1-20 alkyl group in which at least one hydrogen atom (e.g., 1, 2, 3) has been replaced with an aryl group. Examples of such groups include, but are not limited to, benzyl (phenylmethyl, PI1CH2-), benzhydryl (PI12CH-), trityl (triphenylmethyl, PI13C-), phenethyl (phenylethyl, PI1-CH2CH2-), styryl (Ph-CH=CH-), cinnamyl (Ph-CH=CH-CH2-).

[0027] Typically a substituted C1-20 alkyl group carries 1, 2 or 3 substituents, for instance 1 or 2.

[0028] A C1-20 haloalkyl group is a straight or branched chain saturated C1-20 alkyl group in which at least one hydrogen atom has been replaced with a halogen atom, typically F, Cl or Br. In a Cnhaloalkyl group, where n is from 1 to 20, the number of hydrogen atoms replaced with a halogen atom may be from n to (2n+l). The halogen atoms may be the same or different. C1-20 haloalkyl groups include C1-20 fluoroalkyl groups and C1-20 perfluoroalkyl groups, as defined below. A C1-20 haloalkyl group may have at least two halogen atoms or, for instance, at least three halogen atoms.

[0029] A C1-20 fluoroalkyl group is a straight or branched chain saturated C1-20 alkyl group in which at least one hydrogen atom has been replaced with a fluorine atom. In a Cnfluoroalkyl group, where n is from 1 to 20, the number of hydrogen atoms replaced with a fluorine atom may be from n to (2n+l). Thus, Ci-20 fluoroalkyl groups include C1-20 perfluoroalkyl groups, in which all the hydrogen atoms that would otherwise have been present are replaced with a fluorine atom. Typically, a C1-20 fluoroalkyl group has at least two fluorine atoms, more typically at least three fluorine atoms. Typically a C1-20 fluoroalkyl group is a C2-20 fluoroalkyl group, or for instance a C3-20 fluoroalkyl group. Typically, a C2-20 fluoroalkyl group has at least three fluorine atoms, more typically at least four fluorine atoms. Typically, a C3-20 fluoroalkyl group has at least three fluorine atoms, more typically at least four fluorine atoms or, for instance, at least six fluorine atoms.

[0030] A C1-20 perfluoroalkyl group is a straight or branched chain saturated perfluorinated hydrocarbon radical having from 1 to 20 carbon atoms. “Perfluorinated” in this context means completely fluorinated such that there are no carbon-bonded hydrogen atoms replaceable with fluorine. Typically it is C1-12 perfluoroalkyl, for example trifluoromethyl (Ci), pentafluoroethyl (C2), perfluoropropyl (C3) (including pcrfluoro-w-propyl and pcrfluoro- / .so-propyl). perfluorobutyl (C4) (including pcrfluoro-w-butyl. pcrfluoro- / .so-biityl. pcrfluoro-scc-butyl and perfluoro-tert-butyl), perfluoropentyl (C5), perfluorohexyl (Ce), perfluoroheptyl (C7), perfluorooctyl (Cs), perfluorononyl (C>), perfluorodecyl (C10), perfluoroundecyl (Cn) and perfluorododecyl (C12), including straight chained and branched isomers thereof.

[0031] A C1-20 hydrocarbon moiety is a straight-chained or branched, saturated or unsaturated hydrocarbon moiety having from 1 to 20 carbon atoms. A C1-20 hydrocarbon moiety may be unsubstituted or substituted, the substituents, unless otherwise specified, being selected from those listed above for C1-20 alkyl groups. Typically, when a C1-20 hydrocarbon moiety is substituted, it is substituted by from one to four (e.g. one, two, three or four) substituents.

[0032] A tri(Ci-2o alkyl)silyl group represents a group of formula: -Si(R )(R”)(R”’) wherein R’, R” and R’”, which are the same or different, are unsubstituted or substituted, straight or branched chain C1-20 alkyl groups as defined above.

[0033] A aryldi(Ci-2o alkyl)silyl group represents a group of formula: -Si(R )(R”)(R”’) wherein R’ and R”, which are the same or different, are unsubstituted or substituted, straight or branched chain C1-20 alkyl groups as defined above, and wherein R’” is an unsubstituted or substituted aryl group.

[0034] A diaryl(Ci-2o alkyl)silyl group represents a group of formula: -Si(R )(R”)(R”’) wherein R’ is an unsubstituted or substituted, straight or branched chain C1-20 alkyl group as defined above, and wherein R” and R’”, which are the same or different, are unsubstituted or substituted aryl groups.

[0035] A triarylsilyl group represents a group of formula: -Si(R )(R”)(R”’) wherein R’, R” and R’”, which are the same or different, are unsubstituted or substituted aryl groups.

[0036] A C2-20 alkenyl group is a straight or branched group, which contains from 2 to 20 carbon atoms. One or more double bonds may be present in the alkenyl group, typically one double bond. A C2-20 alkenyl group is typically ethenyl or a C3-10 alkenyl group, i.e. a C2-10 alkenyl group, more typically a C2-6 alkenyl group. A C3-10 alkenyl group is typically a C3-6 alkenyl group, for example allyl, propenyl, butenyl, pentenyl or hexenyl. A C2-4 alkenyl group is ethenyl, propenyl or butenyl. An alkenyl group may be unsubstituted or substituted by one to four (e.g. one, two, three or four) substituents, the substituents, unless otherwise specified, being selected from those listed above for C1-20 alkyl groups. Where two or more substituents are present, these may be the same or different.

[0037] A C2-20 alkynyl group is a straight or branched group which, unless otherwise specified, contains from 2 to 20 carbon atoms. One or more triple bonds, and optionally one or more double bonds may be present in the alkynyl group, typically one triple bond. A C2-20 alkynyl group is typically ethynyl or a C3-10 alkynyl group, i.e. a C2-10 alkynyl group, more typically a C2-6 alkynyl group. A C3-10 alkynyl group is typically a C3-6 alkynyl group, for example propynyl, butynyl, pentynyl or hexynyl. A C2-4 alkynyl group is ethynyl, propynyl or butynyl. An alkynyl group may be unsubstituted or substituted by one to four substituents (e.g. one, two, three or four), the substituents, unless otherwise specified, being selected from those listed above for C1-20 alkyl groups. Where two or more substituents are present, these may be the same or different.

[0038] An aryl ring is an unsubstituted or substituted aromatic ring of covalently linked carbon atoms. Typically, the aryl ring is a 5 - or 6- membered aryl ring, examples of which include cyclopentadienyl (Cp) and phenyl. An aryl ring may be unsubstituted or substituted by, typically, one to five substituents (e.g. one, two, three, four or five), the substituents, unless otherwise specified, being selected from those listed above for C1-20 alkyl groups. Where two or more substituents are present, these may be the same or different.

[0039] A heteroaryl ring is an unsubstituted or substituted heteroaromatic ring of covalently linked atoms including one or more heteroatoms. The one or more heteroatoms are typically selected from nitrogen, phosphorus, silicon, oxygen and sulfur (more commonly from nitrogen, oxygen and sulfur). A heteroaryl ring is typically a 5 - or 6- membered heteroaryl ring containing at least one heteroatom selected from nitrogen, phosphorus, silicon, oxygen and sulfur (more commonly selected from nitrogen, oxygen and sulfur). It may contain, for example, 1, 2 or 3 heteroatoms. Examples of heteroaryl rings include pyridine, pyrazine, pyrimidine, pyridazine, furan, thiofuran, pyrazole, pyrrole, oxazole, oxadiazole, isoxazole, thiadiazole, thiazole, isothiazole, imidazole and pyrazole. A heteroaryl ring may be unsubstituted or substituted by, typically, one to four substituents (e.g. one, two, three or four), the substituents, unless otherwise specified, being selected from those listed above for C1-20 alkyl groups. Where two or more substituents are present, these may be the same or different.

[0040] A C5-10 carbocyclic ring is an unsubstituted or substituted closed ring of from 5 to 10 covalently linked carbon atoms, which ring is saturated or unsaturated. Typically, the C5-10 carbocyclic ring is not an aromatic ring. Typically the C5-10 carbocyclic ring is a C5-6 carbocyclic ring. The carbocyclic ring may be saturated or unsaturated. Thus, the term C5-10 carbocyclic ring includes the sub-classes C5-10 cycloalkyl ring, C5-10 cycloalkyenyl ring and C5-10 cycloalkynyl ring. When a C5- 10 carbocyclic ring is substituted it typically bears one or more substituents selected from those listed above for C1-20 alkyl groups. Examples of C5-10 carbocyclic rings include, but are not limited to: cyclopentane (C5), cyclohexane (Ce), cycloheptane (C7), methylcyclopropane (C4), dimethylcyclopropane (C5), methylcyclobutane (C5), dimethylcyclobutane (Ce), methylcyclopentane (Ce), dimethylcyclopentane (C7), methylcyclohexane (C7), dimethylcyclohexane (Cs), menthane (C10), cyclopentene (C5), cyclopentadiene (C5), cyclohexene (Ce), cyclohexadiene (Ce), methylcyclopropene (C4), dimethylcyclopropene (C5), methylcyclobutene (C5), dimethylcyclobutene (Ce), methylcyclopentene (Ce), dimethylcyclopentene (C7), methylcyclohexene (C7), dimethylcyclohexene (Cs).

[0041] A C5-10 heterocyclic ring is an unsubstituted or substituted closed ring of from 5 to 10 covalently linked atoms, which ring is saturated or unsaturated, wherein at least one of the ring atoms is a multivalent ring heteroatom, for example, nitrogen, phosphorus, silicon, oxygen, or sulfur (though more commonly nitrogen, oxygen, or sulfur). Typically, the C5-10 heterocyclic ring is not an aromatic ring. Typically, the C5-10 heterocyclic ring has from 1 to 4 heteroatoms, the remainder of the ring atoms are carbon. Typically, the C5-10 heterocyclic ring is a C5-6 heterocyclic ring in which from 1 to 4 of the ring atoms are ring heteroatoms, and the remainder of the ring atoms are carbon atoms. In this context, the prefixes C5-10 and C5-6 denote the number of ring atoms, or range of number of ring atoms. When a C5-10 heterocyclic ring is substituted it typically bears one or more substituents selected from those listed above for C1-20 alkyl groups.

[0042] Examples of monocyclic C5-10 heterocyclic rings include, but are not limited to:

[0043] Ni: pyrrolidine (tetrahydropyrrole) (C5), pyrroline (e.g., 3-pyrroline, 2,5 -dihydropyrrole) (C5), 2H-pyrrole or 3H-pyrrole (isopyrrole, isoazole) (C5), piperidine (Ce), dihydropyridine (Ce), tetrahydropyridine (Ce), azepine (C7);

[0044] Oi : oxolane (tetrahydrofuran) (C5), oxole (dihydrofuran) (C5), oxane (tetrahydropyran) (Ce), dihydropyran (Ce), pyran (Ce), oxepin (C7);

[0045] Si: thiolane (tetrahydrothiophene) (C5), thiane (tetrahydrothiopyran) (Ce), thiepane (C7);

[0046] O2: dioxolane (C5), dioxane (Ce), and dioxepane (C7);

[0047] O3: trioxane (Ce);

[0048] N2: imidazolidine (C5), pyrazolidine (diazolidine) (C5), imidazoline (C5), pyrazoline (dihydropyrazole) (C5), piperazine (Ce);

[0049] N1O1: tetrahydrooxazole (C5), dihydrooxazole (C5), tetrahydroisoxazole (C5), dihydroisoxazole (C5), morpholine (Ce), tetrahydrooxazine (Ce), dihydrooxazine (Ce), oxazine (Ce);

[0050] N1S1: thiazoline (C5), thiazolidine (C5), thiomorpholine (Ce);

[0051] N2O1: oxadiazine (Ce);

[0052] Oi Si: oxathiole (C5) and oxathiane (thioxane) (Ce); and,

[0053] N1O1S1: oxathiazine (Ce).

[0054] A C3-20 carbocyclyl group is an unsubstituted or substituted monovalent moiety obtained by removing a hydrogen atom from an alicyclic ring atom of a carbocyclic ring of a carbocyclic compound, which moiety has from 3 to 20 carbon atoms (unless otherwise specified), including from 3 to 20 ring atoms. The carbocyclyl ring may be saturated or unsaturated. Thus, the term "carbocyclyl" includes the sub-classes cycloalkyl, cycloalkyenyl and cycloalkynyl. Preferably, each ring has from 5 to 7 ring atoms. Examples of groups of C3-20 carbocyclyl groups include C3-10 carbocyclyl, C5-7 carbocyclyl and C5-6 carbocyclyl. When a C3-20 carbocyclyl group is substituted it typically bears one or more substituents (typically one, two, three or four substituents) selected from those listed above for C1-20 alkyl groups.

[0055] Examples of C3-20 carbocyclyl groups include, but are not limited to, those derived from saturated monocyclic hydrocarbon compounds: cyclopropane (C3), cyclobutane (C4), cyclopentane (C5), cyclohexane (Ce), cycloheptane (C7), methylcyclopropane (C4), dimethylcyclopropane (C5), methylcyclobutane (C5), dimethylcyclobutane (Ce), methylcyclopentane (Ce), dimethylcyclopentane (C7), methylcyclohexane (C7), dimethylcyclohexane (Cs), menthane (C10); unsaturated monocyclic hydrocarbon compounds: cyclopropene (C3), cyclobutene (C4), cyclopentene (C5), cyclopentadiene (C5), cyclohexene (Ce), cyclohexadiene (Ce), methylcyclopropene (C4), dimethylcyclopropene (C5), methylcyclobutene (C5), dimethylcyclobutene (Ce), methylcyclopentene (Ce), dimethylcyclopentene (C7), methylcyclohexene (C7), dimethylcyclohexene (Cs); saturated polycyclic hydrocarbon compounds: thujane (C10), carane (C10), pinane (C10), bomane (C10), norcarane (C7), norpinane (C7), norbomane (C7), adamantane (Cw), decalin (decahydronaphthalene) (C10); unsaturated polycyclic hydrocarbon compounds: camphene (C10), limonene (C10), pinene (C10); polycyclic hydrocarbon compounds having an aromatic ring: indene (C>), indane (e.g., 2,3-dihydro-lH-indene) (C>), tetraline (1,2,3,4-tetrahydronaphthalene) (C10), acenaphthene (C12), fluorene (C13), phenalene (C13), 5, 5,8,8- tetramethyl tetraline (C14), acephenanthrene (C15), aceanthrene (Cie), cholanthrene (C20).

[0056] Further examples of C3-20 carbocyclyl groups include C3-20 halocarbocyclyl groups, C3-20 fluorocarbocyclyl groups, C3-20 perfluorocarbocyclyl groups and C3-10 cycloalkyl groups.

[0057] A C3-20 halocarbocyclyl group is a C3-20 carbocyclyl group in which at least one hydrogen atom has been replaced with a halogen atom, typically F, Cl or Br. The halogen atoms may be the same or different. C3-20 halocarbocyclyl groups include C3-20 fluorocarbocyclyl groups and C3-20 perfluorocarbocyclyl groups, as defined below. A C3-20 halocarbocyclyl group may have at least two halogen atoms or, for instance, at least three or at least four, at least five or at least six halogen atoms.

[0058] A C3-20 fluorocarbocyclyl group is a C3-20 carbocyclyl group in which at least one hydrogen atom has been replaced with a fluorine atom. C3-20 fluorocarbocyclyl groups include C3-20 perfluorocarbocyclyl groups, as defined below. A C3-20 fluorocarbocyclyl group may have at least two fluorine atoms or, for instance, at least three or at least four, at least five or at least six fluorine atoms. A C3-20 perfluorocarbocyclyl group a perfluorinated C3-20 carbocyclyl group. “Perfluorinated” in this context means completely fluorinated such that there are no carbon-bonded hydrogen atoms replaceable with fluorine.

[0059] A C3-10 cycloalkyl group or moiety is a 3 - to 10- membered unsubstituted or substituted group or moiety, typically a 3 -to 6-membered group or moiety, which may be a monocyclic ring or which may consist of two or more fused rings. Examples of C3-10 cycloalkyl groups or moieties include cyclopropane (C3), cyclobutane (C4), cyclopentane (C5), cyclohexane (Ce), cycloheptane (C7), methylcyclopropane (C4), dimethylcyclopropane (C5), methylcyclobutane (C5), dimethylcyclobutane (Ce), methylcyclopentane (Ce), dimethylcyclopentane (C7), methylcyclohexane (C7), dimethylcyclohexane (Cs), menthane (C10), thujane (C10), carane (C10), pinane (C10), bomane (C10), norcarane (C7), norpinane (C7), norbomane (C7), adamantane (C10) and decalin (decahydronaphthalene) (Cw).

[0060] A C3-20 heterocyclyl group is an unsubstituted or substituted monovalent, monocyclic, bicyclic or tricyclic moiety obtained by removing a hydrogen atom from a ring atom of a heterocyclic compound, which moiety has from 3 to 20 ring atoms (unless otherwise specified), of which from 1 to 10 are ring heteroatoms. Preferably, each ring has from 3 to 7 ring atoms, of which from 1 to 4 are ring heteroatoms. When a C3-20 heterocyclyl group is substituted it typically bears one or more substituents selected from those listed above for C1-20 alkyl groups. Typically a substituted C3-20 heterocyclyl group carries 1, 2 or 3 substituents, for instance 1 or 2.

[0061] Examples of groups of heterocyclyl groups include C3-20 heterocyclyl, C5-20 heterocyclyl, C3-15 heterocyclyl, C5-15 heterocyclyl, C3-12 heterocyclyl, C5-12 heterocyclyl, C3-10 heterocyclyl, C5-10 heterocyclyl, C3-7 heterocyclyl, C5-7 heterocyclyl, and C5-6 heterocyclyl.

[0062] Examples of monocyclic C3-20 heterocyclyl groups include, but are not limited to, those derived from:

[0063] Ni: aziridine (C3), azetidine (C4), pyrrolidine (tetrahydropyrrole) (C5), pyrroline (e.g., 3-pyrroline, 2,5-dihydropyrrole) (C5), 2H-pyrrole or 3H-pyrrole (isopyrrole, isoazole) (C5), piperidine (Ce), dihydropyridine (Ce), tetrahydropyridine (Ce), azepine (C7);

[0064] Oi : oxirane (C3), oxetane (C4), oxolane (tetrahydrofuran) (C5), oxole (dihydrofuran) (C5), oxane (tetrahydropyran) (Ce), dihydropyran (Ce), pyran (Ce), oxepin (C7);

[0065] Si: thiirane (C3), thietane (C4), thiolane (tetrahydrothiophene) (C5), thiane (tetrahydrothiopyran) (Ce), thiepane (C7);

[0066] O2: dioxolane (C5), dioxane (Ce), and dioxepane (C7);

[0067] O3: trioxane (Ce);

[0068] N2: imidazolidine (C5), pyrazolidine (diazolidine) (C5), imidazoline (C5), pyrazoline (dihydropyrazole) (C5), piperazine (Ce);

[0069] N1O1: tetrahydrooxazole (C5), dihydrooxazole (C5), tetrahydroisoxazole (C5), dihydroisoxazole (C5), morpholine (Ce), tetrahydrooxazine (Ce), dihydrooxazine (Ce), oxazine (Ce); Ni Si : thiazoline (C5), thiazolidine (C5), thiomorpholine (Ce);

[0070] N2O1: oxadiazine (Ce);

[0071] Oi Si: oxathiole (C5) and oxathiane (thioxane) (Ce); and,

[0072] N1O1S1: oxathiazine (Ce).

[0073] Examples of C3-20 heterocyclyl groups which are also aryl groups are described below as heteroaryl groups.

[0074] An aryl group is a substituted or unsubstituted, monocyclic or bicyclic aromatic group which typically contains from 6 to 14 carbon atoms, preferably from 6 to 10 carbon atoms in the ring portion. Examples include phenyl, naphthyl, indenyl and indanyl groups. An aryl group is unsubstituted or substituted. When an aryl group as defined above is substituted it typically bears one or more substituents (for instance, one, two, three, four or five substituents) selected from those listed above for C1-20 alkyl groups. A substituted aryl group may be substituted in two positions with a single unsubstituted or substituted C1-6 alkylene group, or with a bidentate group represented by the formula -X-C1-6 alkylene, or -X-C1-6 alkylene-X-, wherein X is selected from O, S and NR, and wherein R is H, aryl or C1-6 alkyl. Thus a substituted aryl group may be an aryl group fused with a cycloalkyl group or with a heterocyclyl group. A further example of a substituted aryl group is a Ce-io perfluoroaryl group.

[0075] A Ce-io perfluoroaryl group is a perfluorinated aryl group which contains from 6 to 10 carbon atoms in the ring portion. “Perfluorinated” in this context means completely fluorinated such that there are no carbon-bonded hydrogen atoms replaceable with fluorine. Typically it is pentafluorophenyl .

[0076] The term aralkyl as used herein, pertains to an aryl group in which at least one hydrogen atom (e.g., 1, 2, 3) has been substituted with a C1-20 alkyl group. Examples of such groups include, but are not limited to, tolyl (from toluene), xylyl (from xylene), mesityl (from mesitylene), and cumenyl (or cumyl, from cumene), and duryl (from durene).

[0077] The ring atoms of an aryl group may include one or more heteroatoms, as in a heteroaryl group. Such an aryl group (a heteroaryl group) is a substituted or unsubstituted mono- or bicyclic heteroaromatic group which typically contains from 6 to 10 atoms in the ring portion including one or more heteroatoms. It is generally a 5 - or 6-membered ring, or two fused rings each of which is the same or different and typically independently selected from a 5 -membered ring and a 6-membered ring, containing at least one heteroatom selected from O, S, N, P, Se and Si. It may contain, for example, 1, 2 or 3 heteroatoms. Examples of heteroaryl groups include pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thienyl, pyrazolidinyl, pyrrolyl, oxazolyl, oxadiazolyl, isoxazolyl, thiadiazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, quinolyl and isoquinolyl. A heteroaryl group may be unsubstituted or substituted, for instance, as specified above for aryl. Typically it carries 0, 1, 2 or 3 substituents. A Ci -20 alkylene group is an unsubstituted or substituted bidentate moiety obtained by removing two hydrogen atoms, either both from the same carbon atom, or one from each of two different carbon atoms, of a hydrocarbon compound having from 1 to 20 carbon atoms (unless otherwise specified), which may be aliphatic or alicyclic, and which may be saturated, partially unsaturated, or fully unsaturated. Thus, the term "alkylene" includes the sub-classes alkenylene (C1-20 alkenylene), alkynylene (C1-20 alkynylene), cycloalkylene, etc. Typically it is CMO alkylene, or C1-6 alkylene. Typically it is C1-4 alkylene, for example methylene, ethylene, i-propylene, n-propylene, t- butylene, s-butylene or n-butylene. It may also be pentylene, hexylene, heptylene, octylene and the various branched chain isomers thereof. An alkylene group may be unsubstituted or substituted, for instance, as specified above for alkyl. Typically a substituted alkylene group carries 1, 2 or 3 substituents, for instance 1 or 2.

[0078] In this context, the prefixes (e.g., C1-4, C1-7, CMO, C2-7, C3-7, etc.) denote the number of carbon atoms, or range of number of carbon atoms. For example, the term "Ci-4alkylene," as used herein, pertains to an alkylene group having from 1 to 4 carbon atoms. Examples of groups of alkylene groups include C1-4 alkylene ("lower alkylene"), C1-7 alkylene and C O alkylene.

[0079] Examples of linear saturated C1-7 alkylene groups include, but are not limited to, -(CFE),,- where n is an integer from 1 to 7, for example, -CH2- (methylene), -CH2CH2- (ethylene), -CH2CH2CH2- (propylene), and -CH2CH2CH2CH2- (butylene).

[0080] Examples of branched saturated C1-7 alkylene groups include, but are not limited to, -CH(CH3)-, -CH(CH3)CH2-, -CH(CH3)CH2CH2-, -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2-, -C H2CH(CH3)CH2CH2-, -CH(CH2CH3)-, -CH(CH2CH3)CH2-, and -CH2CH(CH2CH3)CH2-.

[0081] Examples of linear partially unsaturated C1-7 alkylene groups include, but is not limited to, - CH=CH- (vinylene), -CH=CH-CH2-, -CH2-

[0082] CH=CH2-, -CH=CH-CH2-CH2-, -CH=CH-CH2-CH2-CH2-, -CH=CH-CH=CH-, -CH=CH-CH=CH- CH2-, -CH=CH-CH=CH-CH2-CH2-, -CH=CH-CH2-CH=CH-, and -CH=CH-CH2-CH2-CH=CH-.

[0083] Examples of branched partially unsaturated C1-7 alkylene groups include, but is not limited to, -C(CH3)=CH-, -C(CH3)=CH-CH2-, and -CH=CH-CH(CH3)-.

[0084] Examples of alicyclic saturated C1-7 alkylene groups include, but are not limited to, cyclopentylene (e.g., cyclopent- 1, 3 -ylene), and cyclohexylene (e.g., cyclohex- 1,4-ylene).

[0085] Examples of alicyclic partially unsaturated C1-7 alkylene groups include, but are not limited to, cyclopentenylene (e.g., 4-cyclopenten-l,3-ylene), cyclohexenylene (e.g., 2-cyclohexen- 1,4-ylene; 3-cyclohexen-l,2-ylene; 2, 5 -cyclohexadien- 1,4-ylene). These are examples of C5-6 cycloalkylene groups.

[0086] An example of a substituted C1-20 alkylene group is a C1-20 perfluoroalkylene group. A C1-20 perfluoroalkylene group is a perfluorinated C1-20 alkylene group. “Perfluorinated” in this context means completely fluorinated such that there are no carbon-bonded hydrogen atoms replaceable with fluorine. Ci-20 alkylene, C1-20 perfluoroalkylene, C1-20 alkyl, C1-20 haloalkyl, C1-20 fluoroalkyl and C1-20 perfluoroalkyl groups as defined herein are either uninterrupted or interrupted by one or more heteroatoms or heterogroups, such as S, O or N(R”) wherein R” is H, Ci-e alkyl or aryl (typically phenyl), or by one or more arylene groups. The arylene groups are typically phenylene, but may be perfluoroarylene groups, for instance tetrafluorophenylene. The phrase “optionally interrupted” as used herein thus refers to a C1-20 alkylene, C1-20 perfluoroalkylene, C1-20 alkyl, C1-20 haloalkyl, C1-20 fluoroalkyl or C1-20 perfluoroalkyl group, as defined above, which is uninterrupted or which is interrupted between adjacent carbon atoms by a heteroatom such as oxygen or sulfur, by a heterogroup such as N(R”) wherein R” is H, aryl or C1-6 alkyl, or by an arylene group. For instance, a C1-20 alkyl group such as n-butyl may be interrupted by the heterogroup N(R”) as follows: -CH2N(R”)CH2CH2CH3, -CH2CH2N(R”)CH2CH3, or -CH2CH2CH2N(R”)CH3. Similarly, an alkylene group such as n-butylene may be interrupted by the heterogroup N(R”) as follows: -CH2N(R”)CH2CH2CH2- -CH2CH2N(R”)CH2CH2-, or -CH2CH2CH2N(R”)CH2-. Typically an interrupted group, for instance an interrupted C1-10 alkylene or C1-20 alkyl group, is interrupted by 1, 2 or 3 heteroatoms or heterogroups, or by 1, 2 or 3 arylene (typically phenylene) groups. More typically, an interrupted group, for instance an interrupted C1-10 alkylene or C1-20 alkyl group, is interrupted by 1 or 2 heteroatoms or heterogroups, or by 1 or 2 arylene (typically phenylene) groups. For instance, a C1-20 alkyl group such as n-butyl may be interrupted by 2 heterogroups N(R”) as follows: -CH2N(R”)CH2N(R”)CH2CH3.

[0087] An arylene group is an unsubstituted or substituted bidentate moiety obtained by removing two hydrogen atoms, one from each of two different aromatic ring atoms of an aromatic compound, which moiety has from 5 to 14 ring atoms (unless otherwise specified). Typically, each ring has from 5 to 7 or from 5 to 6 ring atoms. An arylene group may be unsubstituted or substituted, for instance, as specified above for aryl. Typically a substituted heteroarylene group carries 1, 2 or 3 substituents, for instance 1 or 2.

[0088] In this context, the prefixes (e.g., C5-2o, Ce-2o, C5-14, C5-7, C5-6, etc.) denote the number of ring atoms, or range of number of ring atoms, whether carbon atoms or heteroatoms. For example, the term "C5-6 arylene," as used herein, pertains to an arylene group having 5 or 6 ring atoms. Examples of groups of arylene groups include Cs-2o arylene, Ce-2o arylene, C5-14 arylene, Ce-i4 arylene, Ce-io arylene, C5-12 arylene, C5-10 arylene, C5-7 arylene, C5-6 arylene, C5 arylene, and Ce arylene.

[0089] The ring atoms may be all carbon atoms, as in "carboarylene groups" (e.g., Ce-2o carboarylene, Ce-i4 carboarylene or Ce-io carboarylene).

[0090] Examples of Ce-2o arylene groups which do not have ring heteroatoms (i.e., Ce-2o carboarylene groups) include, but are not limited to, those derived from the compounds discussed above in regard to aryl groups, e.g. phenylene, and also include those derived from aryl groups which are bonded together, e.g. phenylene -phenylene (diphenylene) and phenylene-phenylene-phenylene (triphenylene). Alternatively, the ring atoms may include one or more heteroatoms, as in "heteroarylene groups" (e.g., C5-10 heteroarylene). A heteroarylene group may be unsubstituted or substituted, for instance, as specified above for aryl. Typically a substituted heteroarylene group carries 1, 2 or 3 substituents, for instance 1 or 2.

[0091] Examples of heteroarylene groups include, but are not limited to, those derived from the compounds discussed above in regard to heteroaryl groups. Examples of heteroarylene groups include bidentate groups derived from pyridine, pyrazine, pyrimidine, pyridazine, furan, thiofuran, pyrazole, pyrrole, oxazole, oxadiazole, isoxazole, thiadiazole, thiazole, isothiazole, imidazole and pyrazole.

[0092] A perfluoroarylene group is a perfluorinated arylene group. “Perfluorinated” in this context means completely fluorinated such that there are no carbon-bonded hydrogen atoms replaceable with fluorine. Typically it is tetrafluorophenylene.

[0093] As used herein the term halo is a group selected from -F, -Cl, -Br, and -I.

[0094] As used herein the term keto represents a group of formula: =0

[0095] As used herein the term nitro represents a group of formula: -NO2

[0096] As used herein the term cyano represents a group of formula: -CN

[0097] As used herein the term hydroxyl represents a group of formula: -OH

[0098] As used herein the term thiol represents a group of formula: -SH

[0099] As used herein the term sulfonyl represents a group of formula: -S(0)2R' wherein R' is a C1-10 alkyl group, preferably a C1-6 alkyl group, as defined previously.

[0100] As used herein the term acyl represents a group of formula: -C(=O)R, wherein R is an acyl substituent, for example, a substituted or unsubstituted C1-20 alkyl group, a substituted or unsubstituted C3-20 heterocyclyl group, or a substituted or unsubstituted aryl group. Examples of acyl groups include, but are not limited to, -C(=0)CH3 (acetyl), -C(=O)CH2CH3 (propionyl), -C(=O)C(CH3)3 (t-butyryl), and -C(=O)Ph (benzoyl, phenone).

[0101] As used herein the term acyloxy (or reverse ester) represents a group of formula: -0C(=0)R, wherein R is an acyloxy substituent, for example, substituted or unsubstituted C1-20 alkyl group, a substituted or unsubstituted C3-2oheterocyclyl group, or a substituted or unsubstituted aryl group, typically a C1-6 alkyl group. Examples of acyloxy groups include, but are not limited to, -0C(=0)CH3 (acetoxy), -OC(=O)CH2CH3, -OC(=O)C(CH3)3, -OC(=O)Ph, and -OC(=O)CH2Ph.

[0102] As used herein the term ester (or carboxylate, carboxylic acid ester or oxycarbonyl) represents a group of formula: -C(=0)0R, wherein R is an ester substituent, for example, a substituted or unsubstituted C1-20 alkyl group, a substituted or unsubstituted C3-20 heterocyclyl group, or a substituted or unsubstituted aryl group (typically a phenyl group). Examples of ester groups include, but are not limited to, -C(=0)0CH3, -C(=O)OCH2CH3, -C(=O)OC(CH3)3, and -C(=O)OPh.

[0103] As used herein the term amino represents a group of formula -NH2. The term C1-C10 alkylamino represents a group of formula -NHR' wherein R' is a C1-10 alkyl group, preferably a C1-6 alkyl group, as defined previously. The term di(Ci-io)alkylamino represents a group of formula -NR'R” wherein R' and R” are the same or different and represent Ci-w alkyl groups, preferably Ci-6 alkyl groups, as defined previously. The term arylamino represents a group of formula -NHR' wherein R' is an aryl group, preferably a phenyl group, as defined previously. The term diarylamino represents a group of formula -NR'R” wherein R' and R” are the same or different and represent aryl groups, preferably phenyl groups, as defined previously. The term arylalkylamino represents a group of formula -NR'R' ' wherein R' is a Ci-io alkyl group, preferably a Ci-6 alkyl group, and R” is an aryl group, preferably a phenyl group.

[0104] As used herein the term amido represents a group of formula: -C(=O)NR R ”, wherein R and R are independently H or amino substituents, as defined for di(Ci-io)alkylamino groups. Examples of amido groups include, but are not limited to, -C(=O)NH2, -C(=O)NHCH3, -C(=O)N(CH3)2, -C(=O)NHCH2CH3, and -C(=O)N(CH2CH3)2, as well as amido groups in which R and R ”, together with the nitrogen atom to which they are attached, form a heterocyclic structure as in, for example, piperidinocarbonyl, morpholinocarbonyl, thiomorpholinocarbonyl, and piperazinocarbonyl.

[0105] As used herein, the terms “carboxy”, “carboxyl” and “carboxylic acid” each represent a group of the formula: -C(=O)OH, or -COOH. As would be understood by the skilled person, a carboxylic acid group (for instance, when employed in the present invention) can exist in protonated and deprotonated forms (for example, -C(=O)OH and -C(=O)O ), and in salt forms (for example, - C(=O)O X+, wherein X+is a monovalent cation).

[0106] As used herein the term acylamido represents a group of formula: -NRxC(=O)Ry, wherein Rxis an amide substituent, for example, hydrogen, a Ci.2oalkyl group, a C3.2o heterocyclyl group, an aryl group, preferably hydrogen or a C1-20 alkyl group, and Ryis an acyl substituent, for example, a C1-20 alkyl group, a C3.2o heterocyclyl group, or an aryl group, preferably hydrogen or a C1-20 alkyl group. Examples of acylamide groups include, but are not limited to, -NHC(=O)CH3, -NHC(=O)CH2CH3, -NHC(=O)Ph, -NHC(=O)CI5H3I and -NHC(=O)C9HI9. Thus, a substituted C1-20 alkyl group may comprise an acylamido substituent defined by the formula -NHC(=0)-Ci-2o alkyl, such as -NHC(=O)Ci5H3ior -NHC(=O)C9HI9. Rxand Rymay together form a cyclic structure, as in, for example, succinimidyl, maleimidyl, and phthalimidyl: succinimidyl maleimidyl phthalimidyl

[0107] A Ci-io alkylthio group is a said Ci-io alkyl group, preferably a Ci-6 alkyl group, attached to a thio group. An arylthio group is an aryl group, preferably a phenyl group, attached to a thio group. A Ci-20 alkoxy group is a said substituted or unsubstituted C1-20 alkyl group attached to an oxygen atom. A CMO alkoxy group is a said substituted or unsubstituted C O alkyl group attached to an oxygen atom. A C1-6 alkoxy group is a said substituted or unsubstituted C1-6 alkyl group attached to an oxygen atom. A C1.4 alkoxy group is a substituted or unsubstituted C1-4 alkyl group attached to an oxygen atom. Said C1-20, CMO, C1-6 and C1.4 alkyl groups are optionally interrupted as defined herein. Examples of C1.4 alkoxy groups include, -OMe (methoxy), -OEt (ethoxy), -O(nPr) (n-propoxy), - O(iPr) (isopropoxy), -O(nBu) (n-butoxy), -O(sBu) (sec-butoxy), -O(iBu) (isobutoxy), and -O(tBu) (tert-butoxy). Further examples of C1-20 alkoxy groups are -O(Adamantyl), -O-CFf-Adamantyl and - O-CFE-CFE-Adamantyl. An aryloxy group is a substituted or unsubstituted aryl group, as defined herein, attached to an oxygen atom. An example of an aryloxy group is -OPh (phenoxy).

[0108] As used herein, the term “sulfonic acid” represents a group of the formula: -S(=O)2OH. As would be understood by the skilled person, a sulfonic acid group can exist in protonated and deprotonated forms (for example, -S(=O)2OH and -S(=O)2O ), and in salt forms (for example, - S(=O)2O X+, wherein X+is a monovalent cation).

[0109] As used herein, the term “sulfonamide” represents a group of formula: -S(O)2NH2.

[0110] “Molecular weight” in the context of a polymer as described herein can be expressed as either a number average molecular weight (Mn), or a weight average molecular weight or a peak molecular weight. Unless otherwise indicated, all references to molecular weight of a polymer herein refer to the number average molecular weight. These molecular weight determinations, number average, weight average and peak, can be measured using gel permeation chromatography or other liquid chromatography techniques. Other methods for measuring molecular weight values can also be used, such as the use of end group analysis or the measurement of colligative properties (e.g., freezing point depression, boiling point elevation, or osmotic pressure) to determine number average molecular weight, or the use of light scattering techniques, ultracentrifugation or viscometry to determine weight average molecular weight. Unless otherwise indicated, all references to molecular weight herein refer to the number average molecular weight as measured by gel permeation chromatography.

[0111] Anion-conducting composite material

[0112] The invention provides an anion-conducting composite material which comprises: (a) a porous support material; and (b) a composition disposed on the porous support material, wherein the composition comprises: (i) a cationic polymer, and (ii) a reacted crosslinker.

[0113] Typically, the reacted crosslinker is obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer. The crosslinker compound comprises at least three of said reactive intermediate precursor groups. In other words, the crosslinker compound comprises n of said reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3.

[0114] The term “reactive intermediate precursor group”, as used herein, means a latent reactive group which is capable of being converted into a reactive intermediate group (specifically, into a carbene or nitrene reactive intermediate group) by a chemical process or by the application of energy, wherein the reactive intermediate group is capable of further reaction. The “application of energy” may for instance involve the application of thermal energy (i.e. heating) or irradiation, although any suitable source of energy can be used. The reactive intermediate groups are typically generated by a thermal process and / or by an irradiation process, but can be generated chemically. Typically, the reactive intermediate groups are generated by thermal irradiation, for instance by heating, especially when the groups are hydrazone or diazo groups and the reactive intermediate is a carbene reactive intermediate. This heat might be applied to the crosslinker compound externally, for example by using a hot press, but may also be as a result of another process, for example, extrusion. Alternatively, the reactive intermediate groups may be generated by electromagnetic radiation, for instance by UV, microwave or laser irradiation, or by ultrasonic irradiation.

[0115] The reactive intermediate precursor groups employed in the present invention are selected from carbene precursor groups and nitrene precursor groups. “Carbene precursor groups”, i.e. are capable of conversion into carbene reactive intermediates, whereas “nitrene precursor groups”, i.e. are capable of conversion into nitrene reactive intermediates.

[0116] The carbene precursor groups employed in the present invention are selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): wherein, in formula (A), R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group.

[0117] The n reactive intermediate precursor groups in the crosslinker compound may be the same or different. For instance, the n reactive intermediate precursor groups in the crosslinker compound may all be carbene precursor groups, or they may all be nitrene precursor groups (i.e. azide groups of formula D), or some of them may be carbene precursor groups and the others may be nitrene precursor groups. Usually, however, the n reactive intermediate precursor groups in the crosslinker compound are either all nitrene groups (azide groups of formula D), or they are all carbene precursor groups. When the n reactive intermediate precursor groups in the crosslinker compound comprise carbene precursor groups, the carbene precursor groups may be the same or different and may be independently selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C). Often, however, each of the carbene precursor groups is the same, for instance they may all be hydrazone groups of formula (A), or they may all be diazo groups of formula (B), or they may all be diazirine groups of formula (C).

[0118] Often, the reactive intermediate precursor groups employed in the present invention are carbene precursor groups. The carbene precursor groups are often hydrazone groups of formula (A) or diazo groups of formula (B). More typically, the carbene precursor groups are hydrazone groups of formula (A). Hydrazone groups of formula (A) in which R1is -S(O)2R2are particularly preferred.

[0119] As mentioned above, the reacted crosslinker is obtainable by generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups of the crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0120] The number of reactive intermediate precursor groups in the crosslinker compound, n, is an integer equal to or greater than 3. Often, however, n is greater than or equal to 4.

[0121] In one embodiment, n is an integer of from 3 to 50, more typically an integer of from 3 to 20, or from 3 to 10, or an integer of 3, 4 or 5.

[0122] In other embodiments, however, n is an integer of from 3 to 500, and is more typically an integer of from 3 to 200, from 3 to 100, or from 10 to 100, for instance from 10 to 50.

[0123] In yet another embodiment, n is an integer equal to or greater than 50, for instance equal to or greater than 100. Thus, n may be an integer of from 50 to 1,000,000, from 50 to 100,000, from 50 to 10,000, from 50 to 5,000, or from 50 to 1,000. More typically, in this embodiment, n is an integer of from 50 to 1,000.

[0124] Since the crosslinker compound bears at least 3 reactive intermediate precursor groups which can be converted into carbene or nitrene reactive intermediate groups, one molecule of the crosslinker compound can react with two, or three, or more molecules of another compound - for instance the abovementioned cationic polymer - to form a cross link between the molecules of the other compound. Similarly, a molecule of the crosslinker compound can form a cross link between two, or three, or more different materials, e.g. between the abovementioned cationic polymer and the porous support material. The crosslinker compound can also react with itself intermolecularly, i.e. with other molecules of the crosslinker compound, to build up a three-dimensional cross-linked network. Thus, the crosslinker compound can react both with itself and with any other material or materials with which it is brought into contact, to form a three-dimensional cross-linked network that bonds the materials together, generally by covalent bonding.

[0125] For instance, the crosslinker compound employed in the present invention may be brought into contact with the porous support material and the cationic polymer, and the reactive intermediate precursor groups of the crosslinker compound may then be converted into reactive carbene or nitrene intermediate groups, thereby causing the crosslinker compound to react with itself intermolecularly, and to react with the surface of the porous support material, and to react with molecules of the cationic polymer, thereby forming a cross-linked network between cationic polymer molecules, which network is also bonded to the surface of the porous support material. Note that bonding to the surface of the porous support material can, and typically does, include bonding to the internal surface of the porous support material as well as to the support material’s external surface. Thus the bonding to the surface of the support material typically includes bonding to the walls of pores within the porous support material. Thus, in the resulting network, the reacted crosslinker bonds cationic polymer molecules to each other and to the porous support material. If further compounds or materials are also in contact with the crosslinker compound when the reactive carbene or nitrene intermediate groups are generated, then they too will be incorporated into the crosslinked network that becomes bonded to the porous support material.

[0126] Thus, typically, the carbene or nitrene reactive intermediate groups of the crosslinker compound react with the porous support material and the cationic polymer, to bond the cationic polymer to the porous support material. Often, the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to crosslink the cationic polymer and to bond the cationic polymer to the porous support material. The carbene or nitrene reactive intermediate groups may for instance react with further molecules of the crosslinker compound, and with the porous support material, and with the cationic polymer, to crosslink the cationic polymer and to bond the (crosslinked) cationic polymer to the porous support material.

[0127] Thus, typically, in the anion-conducting composite material of the invention, the reacted crosslinker bonds the cationic polymer to the porous support material. Further, the reacted crosslinker preferably crosslinks the cationic polymer and bonds the cationic polymer to the porous support material. This advantageously reduces the solubility of the polymer in aqueous systems and increases the stability of the composite against solvent swelling. In particular, the reacted crosslinker generally bonds the cationic polymer to a surface of the porous support material. More particularly, the reacted crosslinker preferably crosslinks the cationic polymer and bonds the cationic polymer to a surface of the porous support material. The reacted crosslinker may bond to any part of the surface of the porous support material, including to any part of its external surface or to any part of its internal surface, i.e. to inside walls of pores of the porous support material. In this way, the composition comprising the cationic polymer and the reacted crosslinker may penetrate through the pores of the porous support material, from one side of the support material to another, and thereby form multiple anion- conducting pathways through the porous support material. The reacted crosslinker may only be bonded to part of the surface of the porous support material, or it may for example be bonded to the whole of the surface of the porous support material, such that the composition comprising the cationic polymer and the reacted crosslinker covers, and is bonded to, the entire surface of the porous support material including the surfaces inside the pores of the porous support material. As will be discussed further below, the composition comprising the cationic polymer and the reacted crosslinker may completely fill the pores of the porous support material, such that the anion-conducting composite material is not itself porous, or it may not completely fill pores of the porous support material, such that the anion-conducting composite material is itself porous.

[0128] Porous support material

[0129] The porous support material provides physical strength to the composite material of the invention, and is generally chemically and thermally stable. It contains pores so that the composition comprising the cationic polymer and the reacted crosslinker can bond to the insides of the pores and thereby form pathways of the anion-conducting material through the porous support. The porous support material may be made of (i.e. it may comprise, or consist of) one or more chemically inert materials.

[0130] The porous support material is typically insoluble in water and thermally stable. The support material is usually, for instance, stable at temperatures of up to 100 °C at least, and is preferably stable at temperatures significantly higher than that. It may for instance be able to withstand temperatures of up to 200 °C, or up to 400 °C, or 600 °C, or even up to 1000 °C or 2000 °C, without degrading or melting.

[0131] The porous support material is typically stable (i.e. it will not dissolve or degrade) in pH- neutral water (or aqueous solution) at temperatures up to and including 100 °C. It is preferably also stable (i.e. will not dissolve or degrade) in alkaline water (or aqueous solution) at temperatures up 100 °C, and / or in acidic water (or aqueous solution) at temperatures up 100 °C. For instance, the porous support material is typically stable (i.e. it will not dissolve or degrade) in water (or aqueous solution) at a pH of from 5 to 9 at temperatures up 100 °C, and is preferably stable in water (or aqueous solution) having a pH of from 3 to 11 at temperatures up 100 °C. It may for instance be stable in water (or an aqueous solution), at temperatures up 100 °C, having a pH of from 2 to 12, or for instance having a pH of from 1 to 13, or from 0 to 14.

[0132] Thus the porous support material typically has physical strength, chemical inertness (including stability in solvents including water) and thermal stability.

[0133] Another preferred quality of the porous support material is that it is flexible, so that it can bend or twist or otherwise easily be manipulated without breaking. The porous support material may for instance be a flexible porous membrane.

[0134] The porous support material preferably contains non-tortuous pores. As the skilled person will appreciate, a non-tortuous pore provides a non-tortuous pathway through the porous support material. It may for instance provide a substantially straight pathway through the porous support material, from one side of the porous support material to the other, or a pathway that only gently curves or slightly bends. The tortuosity of the pores of the support material may be low enough such that light can pass through each pore, from one side of the porous support material to another.

[0135] Tortuosity of a pathway may be quantified in simple terms using the arc-chord ratio: the ratio of the length of the pathway (L) to the distance between its ends (D). A straight pathway has an arc- chord ratio, L / D of 1, whereas for a circular pathway it is infinity. Thus, typically, the porous support material employed in the present invention contains a plurality of pores, wherein each pore forms a pathway through the support material, from a first end of the pore at a first surface of the support material, to a second end of the pore at a second surface of the support material, wherein, for each of said pores, the ratio of the length, L of said pathway, to the distance, D between said first and second ends, L / D, is in the range of from 1 to 50. L may for instance be from 1 to 20. Typically, for each of said pores, the ratio L / D is from 1 to 10, for instance from 1 to 5, or from 1 to 3, more preferably from 1 to 2. In some embodiments, for each of said pores, the ratio L / D is approximately 1, i.e. each of said pores provides an approximately straight pathway through the porous support material. The arcchord ratio of a pore can be measured using microscopy, for instance electron microscopy, by determining on the micrograph the distance D, from one end of the pore to the other, and by also observing and measuring the length along the pathway of the pore, L, as seen on the micrograph.

[0136] Such non-tortuous pores, or pores of low tortuosity, are advantageous in the present invention because they allow the composition comprising the cationic polymer and the reacted crosslinker to form pathways of low tortuosity, or non-tortuous pathways, through the support material, and thereby facilitate anion conduction through the material via as direct a route as possible. This increases the efficiency of anion conduction through the anion-conducting composite material of the invention.

[0137] The porous support material may for instance be a porous membrane. When the porous support material is a membrane the anion-conducting composite material of the invention may be an anion exchange membrane.

[0138] The porous membrane typically has a thickness of from 1 pm to 500 pm. Often, for instance the porous membrane has a thickness of from 5 pm to 500 pm, for instance a thickness of from 10 pm to 500 pm.

[0139] The porous membrane may for instance have a thickness of from 5 pm to 300 pm, for instance from 5 pm to 200 pm, or from 10 pm to 200 pm. Often, for instance the porous membrane has a thickness of from 10 pm to 150 pm, for instance a thickness of from 20 pm to 150 pm, or from 25 pm to 125 pm. Such thicknesses are common for anion exchange membranes.

[0140] Typically, the porous membrane has a mesh structure or a net structure. The porous membrane often, for instance, has a net structure.

[0141] When the porous support material is a porous membrane (which may for instance have a mesh or net structure), it is often the case that the composition comprising the cationic polymer and the reacted crosslinker fills the pores (e.g. fills the gaps in the mesh or net). In that case, the anion- conducting composite material does not itself resemble a mesh or a net but instead resembles a continuous film. The anion-conducting composite material may in that case be non-porous, because the pores of the porous membrane (i.e. the gaps in the mesh or net) may all be filled-in completely by the composition such that no pores remain in the composite material. Alternatively, the composite material may still be porous because not all of the pores of the porous membrane (e.g. the gaps in the mesh or net) may be filled-in by the composition comprising the cationic polymer and the reacted crosslinker, and therefore some pores (gaps) may remain, and / or because the composition comprising the cationic polymer and the reacted crosslinker may not completely fill the pores of the porous membrane (e.g. it may not completely fill the gaps in the mesh or net) but only partially fill them such that porosity remains in the composite material.

[0142] Thus the amount of the composition comprising the cationic polymer and the crosslinker that is disposed on the porous support material may be varied during the preparation of the composite material, in order to tailor the porosity of the composite material as desired for the end use. A non- porous anion-conducting composite material may be desired for some end uses, whereas a certain level of porosity in the anion-conducting composite material may be preferred for other end uses.

[0143] In terms of the porous support material, both the porosity and the pore size may be varied widely to suit the desired end use for the anion-conducting composite material. The porous support material may for instance have a porosity of from 0.1 % to 50 %. More often, however, the porosity of the porous support material is from 0.2 % to 30 %, for instance from 0.5 % to 20 %, or more typically from 0.5 % to 15 %. The porosity of the porous support material may for instance be from 1 % to 12 %, for instance from 2 % to 10 %, or from 3 % to 9 %, for instance from 4 % to 8 %, or from 5 % to 7 %. The porosity of the porous support material may for instance be about 6%.

[0144] The pore size of the porous support material, as used herein, refers to the mean pore size of the pores in the porous support material. The porous support material may for instance have a pore size of from 0.2 pm to 100 pm. More often, however, the pore size of the porous support material is from 0.5 pm to 100 pm, for instance from 0.5 pm to 40 pm, or more typically from 0.5 pm to 20 pm. The pore size of the porous support material may for instance be from 1 pm to 20 pm, for instance from 2 pm to 15 pm, or from 5 pm to 15 pm, for instance from 6 pm to 14 pm, or from 8 pm to 12 pm. The pore size of the porous support material may for instance be about 10 pm.

[0145] Often, the porous support material has a porosity of from 0.5 % to 15 % and a pore size of from 0.5 pm to 20 pm, for instance a porosity of from 2 % to 10 % and a pore size of from 5 pm to 15 pm. The porous support material may for instance have a porosity of from 4 % to 8 % and a pore size of from 8 pm to 12 pm.

[0146] The porous support material may for instance be a porous membrane, for instance a mesh, such as a polymer mesh, for instance a nylon mesh, having a porosity and pore size as defined in the preceding paragraphs.

[0147] The porous support material may be made of a wide variety of materials, to provide it with strength, thermal stability, stability in solvents such as water, and / or chemical inertness, as desired. The porous support material may, for instance comprise a polymer, glass or ceramic.

[0148] The porous support material may comprise woven or non-woven fibres. The woven or nonwoven fibres may comprise a polymer, glass or ceramic. The woven or non-woven fibres may form a mesh. Often, the porous support material comprises a polymer. The porous support material may for instance comprise woven or non-woven fibres, which fibres comprise a polymer. The polymer fibres may together form a mesh. Thus, the porous support material may be a polymer mesh.

[0149] When the porous support material comprises a polymer, the polymer may, for instance, comprise, or be, polyphenylene sulphide (PPS), Nylon, polyethylene, polyetheretherketone (PEEK), polysulfone, polyvinylidene fluoride (PVDF) or polypropylene. It may comprise, or be, a natural polymer, for instance cellulose.

[0150] The porous support material is often a porous polymer membrane. The porous polymer membrane may be a polymer mesh. The porosity and pore size of the porous polymer membrane (which may be a polymer mesh) may be as defined above. The porous polymer membrane may comprise Nylon, polyphenylene sulphide (PPS), polyethylene, polyetheretherketone (PEEK), polysulfone, polyvinylidene fluoride (PVDF), cellulose or polypropylene. The porous polymer membrane may for instance comprise woven or non-woven fibres, which fibres comprise Nylon, polyphenylene sulphide (PPS), polyethylene, polyetheretherketone (PEEK), polysulfone, polyvinylidene fluoride (PVDF), cellulose or polypropylene. The membrane may for instance be a mesh of polymer fibres which comprise Nylon, polyphenylene sulphide (PPS), polyethylene, polyetheretherketone (PEEK), polysulfone, polyvinylidene fluoride (PVDF), cellulose or polypropylene.

[0151] The porous support material may for instance be a nylon mesh. The nylon mesh may have a porosity and pore size within the ranges defined above. For instance, the nylon mesh may have a porosity of from 4 % to 8 % and a pore size of from 8 pm to 12 pm, for example a porosity of 6 % and a pore size of 10 pm. The nylon mesh may have a thickness within any of the thickness ranges defined above for the porous membrane, for instance it may have a thickness of from 10 pm to 200 pm.

[0152] Cationic polymer

[0153] The composition comprising the cationic polymer and the reacted crosslinker is described as being disposed on the porous support material. Here, “disposed on”, means disposed on a surface of - meaning on any surface of - the porous support material. This includes any “external” surface of the porous support material, and any “internal” surface of the porous support material, including the inside walls of the pores of the porous support material. Usually, the composition comprising the cationic polymer and the reacted crosslinker is disposed on the inside walls of pores within the porous support material so that it forms pathways of anion-conducting material through the porous support material. The cationic polymer in the composition provides those pathways with anion-conducting functionality.

[0154] The cationic polymer comprises cationic groups. The term “cationic group” as used herein in the context of the cationic polymer, refers to a group which is always cationic, in that it does not need to acquire an extra proton to become cationic. The term “cationic groups” refers to a plurality of such groups. An example of a cationic group is a group which comprises a quaternary nitrogen atom. In such a group, the tetravalent, quaternary nitrogen atom is positively charged. One example of a cationic group which comprises a quaternary nitrogen atom is a quaternary ammonium group. A group which is cationic only when it acquires an extra proton, and is otherwise charge-neutral, is not a “cationic group”, within the meaning of the term used herein to describe the cationic polymer. Thus, an amino (-NH2) group, or a secondary or tertiary amine group, is not a cationic group because such a group only becomes cationic when it acquires an extra proton and is otherwise charge -neutral.

[0155] Indeed, in aqueous systems a primary amino group is neutral (i.e. in the NH2 form) at relatively high pHs, e.g. above 9, and positively charged only at lower pHs when it acquires an extra proton to become -NIT . Therefore, an amino group (primary amine) is not a “cationic group”, within the meaning of the term used herein in connection with the cationic polymer. For the same reason, neither are secondary or tertiary amine groups. A group which comprises a quaternary nitrogen atom, on the other hand, or any other group which is cationic without needing to acquire a proton to become cationic, is a cationic group.

[0156] Thus, the cationic polymer comprises cationic groups.

[0157] The cationic polymer may also comprise a polymer backbone.

[0158] Generally, the cationic groups are covalently-bonded cationic groups. In other words, the cationic groups are part of the covalently-bonded molecular structure of the cationic polymer. Thus, the cationic polymer typically comprises covalently -bonded cationic groups.

[0159] Thus, the cationic polymer may comprise a polymer backbone and said cationic groups covalently bonded to the polymer backbone. The backbone of the polymer may be a hydrocarbon backbone, for instance a hydrocarbon chain, such as an alkylene chain. The cationic groups may be bonded directly to the backbone of the polymer or, for instance, via a side chain or linker. The side chain or linker may be as defined herein for any other linker or may, for instance, be an alkylene group, such as C1-10 alkylene, or an arylene group, or a heteroarylene group, or a plurality of such groups bonded together.

[0160] Additionally, or alternatively, the cationic groups may be within the polymer backbone itself, i.e. part of the backbone. Thus, the cationic groups may be covalently bonded in between other atoms or groups that, together with the cationic groups, form the polymer backbone. The cationic groups may, for instance, be bonded to hydrocarbon groups such as alkylene groups (for instance C1-10 alkylene groups) arylene groups, and / or heteroarylene groups, within the polymer backbone.

[0161] Thus, the cationic polymer may comprise a polymer backbone and the cationic groups may be within the polymer backbone or may be covalently bonded to the polymer backbone.

[0162] Usually, the cationic polymer comprises a repeat unit which comprises a cationic group.

[0163] Thus, typically, the cationic polymer comprises a repeat unit, which repeat unit comprises one of said cationic groups. The repeat unit may comprise more than one cationic group, for instance a plurality of cationic groups. Thus, the cationic polymer may comprise a repeat unit, which repeat unit comprises one or more of said cationic groups. The repeat unit may comprise a plurality of said cationic groups.

[0164] Generally, the cationic polymer comprises a repeat unit which comprises a covalently-bonded cationic group. In other words, a cationic group is part of the covalently-bonded molecular structure of the repeat unit.

[0165] The cationic group or groups may be selected from groups which comprise a quaternary nitrogen atom. Groups which comprise a quaternary nitrogen atom include quaternary ammonium groups, and heterocyclic groups (for instance C3-20 heterocyclyl groups and heteroaryl groups) which contain a quaternary nitrogen ring atom. Heterocyclic groups which contain a quaternary nitrogen ring atom include, but are not limited to, quaternary imidazolium groups, quaternary pyridinium groups and quaternary pyrrolidinium groups. The cationic group or groups may therefore be selected from quaternary ammonium groups and heterocyclic groups (for instance C3-20 heterocyclyl groups and heteroaryl groups) which contain a quaternary nitrogen ring atom. The cationic group or groups may for instance be selected from quaternary ammonium groups, quaternary imidazolium groups, quaternary pyridinium groups and quaternary pyrrolidinium groups.

[0166] The cationic group or groups may also be selected from groups which comprise a quaternary phosphorus atom, for instance quaternary phosphonium groups.

[0167] The cationic group or groups may also be selected from groups which comprise a tertiary sulfur atom, for instance tertiary sulfonium groups.

[0168] Thus, the cationic polymer may comprise groups which comprise a quaternary nitrogen atom, groups which comprise a quaternary phosphorus atom, or groups which comprise a tertiary sulfur atom. As the skilled person will appreciate, quaternary nitrogen atoms, quaternary phosphorus atoms, and tertiary sulfur atoms, are positively charged.

[0169] The cationic polymer may for instance comprise quaternary ammonium groups, heterocyclic groups (for instance C3-20 heterocyclyl groups and heteroaryl groups) which contain a quaternary nitrogen ring atom, quaternary phosphonium groups, or tertiary sulfonium groups.

[0170] The cationic polymer often comprises quaternary ammonium groups, quaternary imidazolium groups, quaternary pyridinium groups, quaternary pyrrolidinium groups, quaternary phosphonium groups or tertiary sulfonium groups. It may for instance comprise quaternary ammonium groups, quaternary imidazolium groups, quaternary pyridinium groups, or quaternary pyrrolidinium groups.

[0171] The cationic polymer may comprise repeat units of formula (Xi) wherein R° is unsubstituted or substituted CMO alkyl, for instance an unsubstituted C1-4 alkyl group. Typically, R° is methyl.

[0172] Where the cationic polymer comprises repeat units of a particular formula, those repeat units may be, or may not be, the only repeat units in the polymer. For instance, the cationic polymer may be a cationic copolymer, comprising more than one type of repeat unit.

[0173] For instance, a cationic polymer which comprises repeat units of formula (Xi) may further comprise repeat units of formula (

[0174] Thus, the cationic polymer may be a cationic copolymer comprising repeat units of formula (Xi) and repeat units of formula (Xv). The cationic polymer may for instance comprise, or be, a copolymer of 3-methyl-l-vinyl-lH-imidazolium chloride and l-vinyl-2-pyrrolidinone. The cationic polymer may for instance comprise, or be, Luviquat® Excellence, which is commercially available from BASF.

[0175] The cationic polymer may comprise repeat units of formula (Xii) wherein Rpand RQare independently selected from unsubstituted or substituted CMO alkyl, for instance unsubstituted C1.4 alkyl groups. Typically, at least one of Rpand RQis methyl. Typically, both of Rpand RQare methyl. The cationic polymer may for instance comprise, or be, polydiallyldimethylammonium chloride (pDADMAC). pDADMAC is commercially available, for instance from Sigma-Aldrich.

[0176] The cationic polymer may comprise repeat units of formula (Xiii)

[0177] wherein RR, Rsand RTare independently selected from unsubstituted or substituted CMO alkyl, for instance unsubstituted C1.4 alkyl groups. Typically, at least one of RR, Rsand RTis methyl. Often, each of RR, Rsand RTis methyl. The cationic polymer may for instance comprise, or be, polyvinylbenzyltrimethyl ammonium chloride (pVBTMA). pVBTMA is commercially available, for instance from Scientific Polymer Products, Inc. or may be readily produced by polymerising the corresponding monomer, (vinylbenzyl)trimethyl ammonium chloride, which is also commercially available, for instance from Sigma-Aldrich.

[0178] The cationic polymer may comprise repeat units of formula wherein Ruis unsubstituted or substituted Ci-w alkyl, for instance an unsubstituted C1-4 alkyl group. Typically, Ruis methyl. The cationic polymer may for instance comprise, or be, poly(l- methyl-4-vinylpyridinium bromide) or poly( 1 -methyl -2 -vinylpyridinium bromide) . Poly( 1 -methyl -4- vinylpyridinium bromide) and poly(l -methyl -2 -vinylpyridinium bromide) are commercially available, for instance from Polysciences, Inc.

[0179] Thus, the cationic polymer may comprise repeat units having any of the following formulae:

[0180] wherein R°, Rp, RQ, RR, Rs, RTand Ruare independently selected from unsubstituted or substituted CMO alkyl groups. Usually, R°, Rp, RQ, RR, Rs, RTand Ruare independently selected from unsubstituted C1-4 alkyl groups. Typically, R°, Rp, RQ, RR, Rs, RTand Ruare methyl groups.

[0181] The cationic polymer may for instance comprise repeat units of formula (Xi) and repeat units of formula (Xv): unsubstituted C1.4 alkyl group. Typically, R° is methyl.

[0182] The cationic polymer may further comprise a head group. For instance, any of the cationic polymers described above may further comprise at least one head group in addition to the repeat units described above. The head group may be present at an end of the polymer, for instance it may be a terminal head group. A head group can be included to tune the physical and / or chemical properties of the cationic polymer. In particular, the use of head groups can be desirable for improving the physical properties of the polymer, and / or for improving the water resistance of the cationic polymer.

[0183] The head group itself may comprise a cationic group, for instance a group which comprises a quaternary nitrogen atom, a quaternary phosphorus atom, or a tertiary sulfur atom (each of which may be as further defined above).

[0184] Alternatively, the head group may not comprise any group which comprises a quaternary nitrogen atom, a quaternary phosphorus atom, or a tertiary sulfur atom. For instance, the head group may not comprise any cationic groups.

[0185] The cationic polymer employed in the present invention typically further comprises counter anions. Relative to a given molecule of the cationic polymer, the counter anions are typically mobile. Thus, the cationic polymer typically further comprises mobile counter anions.

[0186] Typically, the counter anions are selected from halide, hydroxide and carbonate anions. The halide anions are typically chloride, bromide or iodide anions.

[0187] A cationic polymer with hydroxide counter anions may readily be produced by soaking a cationic polymer with halide counter anions in hydroxide solution, or by soaking a cationic polymer with carbonate counter anions in hydroxide solution, to exchange the halide or carbonate counter anions for hydroxide counter anions. Hydroxide counter anions are preferred if the anion-conducting composite material is for use as an anion exchange membrane .

[0188] A cationic polymer with carbonate counter anions may also readily be produced by allowing a cationic polymer with hydroxide counter anions to react with carbon dioxide, for instance carbon dioxide from the air. Hydroxide counter anions react with carbon dioxide from the air, overtime, to produce carbonate counter anions.

[0189] Thus, the cationic polymer may further comprise counter anions, typically mobile counteranions. The counter anions may comprise halide anions (for instance chloride, bromide or iodide anions). The counter anions may comprise hydroxide anions. The counter anions may comprise carbonate anions. The counter anions may be selected from hydroxide anions, halide anions and carbonate anions. Preferably, the counter anions comprise hydroxide anions.

[0190] The cationic polymer may for instance comprise: a copolymer of 3 -methyl- 1 -vinyl- 1H- imidazolium chloride and l-vinyl-2-pyrrolidinone (for instance, Luviquat® Excellence), a copolymer of 3-methyl-l-vinyl-lH-imidazolium halide and l-vinyl-2-pyrrolidinone, a copolymer of 3-methyl-l- vinyl-lH-imidazolium hydroxide and l-vinyl-2-pyrrolidinone, a copolymer of 3-methyl-l-vinyl-lH- imidazolium carbonate and l-vinyl-2-pyrrolidinone, polydiallyldimethylammonium chloride (pDADMAC), polydiallyldimethylammonium halide, polydiallyldimethylammonium hydroxide, polydiallyldimethylammonium carbonate, polyvinylbenzyltrimethyl ammonium chloride (pVBTMA), polyvinylbenzyltrimethyl ammonium halide, polyvinylbenzyltrimethyl ammonium hydroxide, polyvinylbenzyltrimethyl ammonium carbonate, poly(l -methyl -4-vinylpyridinium bromide) or poly(l -methyl -2 -vinylpyridinium bromide), poly(l -methyl -4-vinylpyridinium halide), poly(l -methyl -4 -vinylpyridinium hydroxide) or poly(l -methyl -4-vinylpyridinium carbonate).

[0191] The cationic polymer may for instance comprise: a copolymer of 3 -methyl- 1 -vinyl- 1H- imidazolium chloride and l-vinyl-2-pyrrolidinone (for instance, Luviquat® Excellence), polydiallyldimethylammonium chloride (pDADMAC), polyvinylbenzyltrimethyl ammonium chloride (pVBTMA), poly(l -methyl -4-vinylpyridinium bromide) or poly(l -methyl -2 -vinylpyridinium bromide). The cationic polymer may for instance comprise any of the aforementioned polymers in which the chloride or bromide counter anions have been exchanged for hydroxide anions, carbonate anions, and / or a different halide.

[0192] In addition to the cationic polymer and the reacted crosslinker, the composition disposed on the porous support material may further comprise one or more further cationic compounds.

[0193] Typically, the or each further cationic compound is independently a further cationic polymer or a cationic small molecule.

[0194] The or each further cationic polymer may be as further defined anywhere herein for the cationic polymer. Thus, the composition disposed on the porous support material may further comprise a second cationic polymer, which is typically different from the cationic polymer but may be as further defined herein for the cationic polymer.

[0195] The or each cationic small molecule typically comprises a small molecule cation. The small molecule cation may be a quaternary ammonium cation, a quaternary phosphonium cation, a tertiary sulfonium cation, or a heterocyclic cation (for instance a C3-20 heterocyclic cation or a heteroaryl cation) which contains a quaternary nitrogen ring atom. The heterocyclic cation which contains a quaternary nitrogen ring atom may for instance be a quaternary imidazolium cation, a quaternary pyridinium cation, or a quaternary pyrrolidinium cation. An example of a small molecule cation which is a quaternary ammonium cation is benzyltriethylammonium. The or each cationic small molecule typically further comprises a counter anion. The counter anion of the cationic small molecule is often a halide. Alternatively, the counter anion may be hydroxide or carbonate.

[0196] The or each cationic small molecule may for instance be selected from quaternary ammonium salts, salts of heterocyclic compounds (for instance C3-20 heterocyclic compounds or heteroaryl compounds) which contain a quaternary nitrogen ring atom, quaternary phosphonium salts, and tertiary sulfonium salts.

[0197] The or each cationic small molecule may for instance be selected from quaternary ammonium salts, quaternary imidazolium salts, quaternary pyridinium salts, quaternary pyrrolidinium salts, quaternary phosphonium salts and tertiary sulfonium salts. The or each cationic small molecule may for instance be selected from quaternary ammonium salts, quaternary imidazolium salts, quaternary pyridinium salts, and quaternary pyrrolidinium salts. Often, benzyltriethylammonium chloride is employed as the cationic small molecule. Thus, the composition disposed on the porous support material may further comprise a cationic small molecule, which may be as further defined above. The ratio by weight of the cationic polymer to the cationic small molecule in the composition disposed on the porous support material may, for instance, be from 2 : 1 to 10: 1, for instance from 3 : 1 to 7 : 1 . It may for instance be about 5: 1.

[0198] Also, in addition to the reacted crosslinker, the cationic polymer, and any further cationic compounds that may be present, the composition disposed on the porous support material may further comprise one or more further reacted crosslinkers. The one or more of the further reacted crosslinkers may be as defined herein for the reacted crosslinker. For instance, one or more of the further reacted crosslinkers may be a reacted crosslinker which is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein. Thus, the composition disposed on the porous support material may further comprise a second reacted crosslinker, which is typically different from the reacted crosslinker but may be as further defined herein for the reacted crosslinker.

[0199] Reacted crosslinker and crosslinker compound

[0200] As discussed above, the reacted crosslinker is typically obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0201] The crosslinker compound comprises n of said reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, and the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups. The carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): wherein, in f 6 alkyl group or an unsubstituted or substituted aryl group.

[0202] The n reactive intermediate precursor groups employed in the crosslinker compound may be nitrene precursor groups, i.e. azide groups of formula (D). The decomposition of azide groups to form reactive nitrene intermediate groups is thought to occur by elimination of dinitrogen to form the reactive nitrene intermediate. As discussed above, this can be initiated by the application of energy, typically by heating or by irradiation. Alternatively, the reactive nitrene intermediate can be generated chemically. Often, however, the n reactive intermediate precursor groups employed in the crosslinker compound are carbene precursor groups.

[0203] Thus, typically, the reactive intermediate precursor groups of the crosslinker compound are carbene precursor groups selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C): wherein lkyl group or an unsubstituted or substituted aryl group.

[0204] The carbene precursor groups may be diazirine groups of formula (C). The decomposition of such diazirine groups to form reactive carbene intermediate groups is thought to occur by elimination of dinitrogen to form the reactive carbene intermediate. As discussed above, this can be initiated by the application of energy, typically by heating or by irradiation. Alternatively, the reactive carbene intermediate can be generated chemically.

[0205] Often, however, the carbene precursor groups are selected from hydrazone groups of formula (A) and diazo groups of formula (B).

[0206] The carbene precursor groups may for instance be diazo groups of formula (B). The decomposition of such diazo groups to form reactive carbene intermediate groups is thought to occur by elimination of dinitrogen to form the reactive carbene intermediate. As discussed above, this can be initiated by the application of energy, typically by heating or by irradiation. Alternatively, the reactive carbene intermediate can be generated chemically.

[0207] Preferably, however, the carbene precursor groups are hydrazone groups of formula (A).

[0208] In the hydrazone groups of formula (A), R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group.

[0209] Often, R1is H.

[0210] However, hydrazone groups of formula (A) in which R1is -S(O)2R2are often preferred.

[0211] Typically, R2is an unsubstituted or substituted Ci-6 alkyl group, an unsubstituted or substituted phenyl group, or an unsubstituted or substituted naphthyl group. Often, R2is Ci-6 alkyl, phenyl or naphthyl, which phenyl or naphthyl is unsubstituted or substituted with Ci-6 alkyl, di(Ci-e alkyl)amino, hydroxyl, nitro, cyano or methoxy.

[0212] More typically, R2is Ci-6 alkyl, phenyl or naphthyl, which phenyl or naphthyl is unsubstituted or substituted with Ci-6 alkyl or di(Ci-e alkyl)amino. Typically, R1is -S(O)2R2wherein R2is phenyl substituted with Ci-6 alkyl. More typically, R1is -S(O)2R2wherein R2is phenyl substituted with methyl (i.e. tolyl). Thus, often, R1is a tosyl group. In another embodiment, R1is H.

[0213] Hydrazone groups of formula (A) are “carbene precursor groups”, because they are capable of conversion into carbene reactive intermediates. When R1is H this conversion may be achieved by oxidation of the hydrazone to a diazomethane followed by the application of energy, typically by heating or by irradiation. When R1is -S(O)2R2conversion of the N-sulfonylhydrazone group into the carbene reactive intermediate may be achieved by the application of energy, typically by heating or by irradiation (for instance by electromagnetic radiation, for instance by UV, microwave or laser irradiation, or by ultrasonic irradiation). The conversion is often achieved by the application of heat. The heat might be applied to the crosslinker compound externally, for example by using a hot press, but may also be as a result of another process, for example, extrusion. Additionally or alternatively, the conversion may be achieved chemically. For instance, conversion of the N-sulfonylhydrazone group into the carbene reactive intermediate may be achieved by treatment with a base followed by the application of energy, typically by heating or by irradiation. Any suitable base may be used, for instance an organic base such as a trialkyl amine (e.g. triethylamine) or l,8-diazabicyclo[5.4.0]undec- 7-ene (DBU). Alternatively an inorganic base may be used, such as an alkali metal hydroxide, e.g. sodium, lithium or potassium hydroxide. The decomposition of the sulfonyl hydrazone to the carbene is thought to occur by elimination of R1, to form a diazo intermediate group, and subsequent elimination of dinitrogen to form the reactive carbene intermediate. Accordingly, the carbene precursor groups may be hydrazone groups of formula (A) as defined above.

[0214] Thus, often, the reactive intermediate precursor groups of the crosslinker compound are carbene precursor groups selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C): wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group. Thus, the reacted crosslinker is typically obtainable by generating carbene reactive intermediate groups from the carbene precursor groups, so that the carbene reactive intermediate groups react with the porous support material and the cationic polymer.

[0215] Alternatively, the reactive intermediate precursor groups of the crosslinker compound are nitrene precursor groups, which are azide groups of formula (D):

[0216] Thus, the reacted crosslinker may be obtainable by generating nitrene reactive intermediate groups from the nitrene precursor groups, so that the nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0217] Often, the crosslinker compound is a polyimide polymer comprising repeat units of formula (X) wherein

[0218] E is a carbene precursor group selected from a hydrazone group of formula (A), a diazo group of formula (B), and a diazirine group of formula (C); and each Lxis a spacer group.

[0219] The number of repeat units of formula (X) in the polyimide polymer is generally at least 3, i.e. it is equal to or greater than 3. The number of repeat units is often equal to or less than 500,000. Thus, the number of repeat units of formula (X) may, for instance, be from 3 to 500,000. The number of said repeat units may, for example, be from 5 to 500,000, or for instance from 10 to 500,000. Often, the number of repeat units of formula (X) is from 10 to 300,000, or, for instance, from 20 to 100,000, or from 20 to 50,000, or from 20 to 10,000. Typically, the number of repeat units of formula (X) is from 10 to 5,000, for instance from 20 to 1,000.

[0220] A wide range of molecular weights, Mn, are possible for the polyimide polymer considering, for instance, the number of repeat units of formula (X), which may, for instance, be as low as three, or as high as 500,000, and considering the nature of the spacer group, Lx, which may be a small linker (e.g. ethylene or methylene) or a larger (e.g. polypropylene glycol) chain. The molecular weight (Mn) of the polymer comprising repeat units of formula (X) may for instance be at least 1,500 Da. Often, the Mnof the polymer is at least 2,000 Da, for instance at least 5,000 Da, or at least 10,000 Da. The Mnof the polymer comprising repeat units of formula (X) may be as high as 250 MDa, for instance less than or equal to 100 MDa, less than or equal to 20 MDa, less than or equal to 10 MDa, or less than or equal to 1 MDa. More typically, the Mnof the polymer comprising repeat units of formula (X) is less than or equal to 500 kDa, for instance less than or equal to 100 kDa, or less than or equal to 50 kDa. Often, the molecular weight (Mn) of the polymer comprising repeat units of formula (X) is from 1,500 Da to 500,000 Da, for instance from 1,500 Da to 300,000 Da, or for instance, from 1,500 Da to 100,000 Da. The Mnof the polymer comprising repeat units of formula (X) may for instance be from 1,500 Da to 50,000 Da, or for instance from 1,500 Da to 30,000 Da, from 1,500 Da to 20,000 Da, or from 1,500 Da to 10,000 Da.

[0221] E is bonded to a ring carbon atom of the benzene ring in each of the phthalimide (isoindoline- 1, 3-dione) groups. E may be bonded each benzene ring independently at the 4, 5, 6 or 7 position. In other words, E may be bonded to any one of the benzene ring carbon atoms on each benzene ring that is not fused to the five-membered ring. Thus, E is bonded to each phthalimide group at the 4, 5, 6 or 7 position of the group.

[0222] Polyimide polymers of formula (X) may be produced by reacting one or more diamino compounds H2N-LX-NH2 (wherein Lxis a said spacer group) with one or more carbonyl bis(phthalic anhydride) compounds of formula (XA). Mixtures of two or more different diamino compounds H2N-LX-NH2 can be employed so that the spacer group Lxcan differ in different repeat units of formula (X) in the same polymer. to produce a polyimide polymer comprising repeat units of the following formula (XB) and then converting the central carbonyl group in each of the repeat units of formula (XB) into a carbene precursor group E, selected from a hydrazone group of formula (A), a diazo group of formula (B), and a diazirine group of formula (C).

[0223] The one or more compounds of formula (XA) are typically selected from 5,5'- carbonylbis(isobenzofuran-l, 3-dione) and 4, 5'-carbonylbis(isobenzofuran-l, 3-dione). The polymer is typically produced by reacting the diamine compound H2N-LX-NH2 with a single compound of formula (XA). The compound of formula (XA) is typically 5,5'-carbonylbis(isobenzofuran-l,3- dione), which has the following structure: in which case the polymer of formula (X) will comprise repeat units of the following formula (X’) wherein E and Lxare as defined above.

[0224] Alternatively, the compound of formula (XA) may be 4,5'-carbonylbis(isobenzofuran-l,3- dione) which has the following structure: in which case the polymer of formula (X) will comprise repeat units of the following formula (X”) wherein E and Lxare as defined above. Alternatively, the polymer may be produced by reacting the one or more diamino compounds of formula H2N-LX-NH2 with a mixture of 5,5'-carbonylbis(isobenzofuran-l,3-dione) and 4,5'- carbonylbis(isobenzofuran-l, 3-dione), in which case the polymer of formula (X) will comprise repeat units of formula (X’) and repeat units of formula (X”). Similarly, a mixture of two or more different diamino compounds of formula H2N-LX-NH2 can be employed in the reaction, meaning that, different repeat units of formula (X’) and (X”) in the polyimide polymer may contain different spacer groups Lx.

[0225] Typically, however, the compound of formula (XA) is 5,5'-carbonylbis(isobenzofuran-l,3- dione). Usually, therefore, the crosslinker compound is a polyimide polymer comprising repeat units of the following formula (X’)

[0226] Often, when the crosslinker compound is a polymer comprising repeat units of formula (X), (X’) or (X”), E is a hydrazone group of formula (A).

[0227] Usually, E is a hydrazone group of formula (A) in which wherein R1is -S(O)2R2, wherein R2is as defined anywhere herein. In other words, usually E is a sulfonylhydrazone group. Typically, R2is phenyl substituted with Ci-6 alkyl. More typically, R2is phenyl substituted with methyl (i.e. tolyl). Often, R2is para-tolyl. Thus, R1in the hydrazone group of formula (A) is often a tosyl group.

[0228] The ability to generate a carbene from a sulfonylhydrazone group without isolating the diazo group intermediate provides numerous advantages. Such sulfonylhydrazone groups are particularly advantageous because they are capable of being converted into a carbene reactive intermediate group, yet they are more stable than the diazo groups of formula (la). In particular, they act as a protected precursor to the carbene reactive intermediate and thereby allow a greater level of control over unwanted degradation of the functionalized compound of the invention, such as in transport or storage. Of particular significance is the decreased toxicity of a sulfonylhydrazone group over a diazo group. Sulfonylhydrazone groups also offer a greater flexibility with regards to formulation as they are not degraded by carboxylic acids unlike diazo groups such as diazo esters, diazo ketones and alkyl or aryl diazos.

[0229] When the crosslinker compound is a polymer comprising repeat units of formula (X), (X’) or (X”), the spacer group Lxmay be any suitable spacer group, and it may differ between repeat units in the same polymer (because mixtures of two or more different diamino compounds of formula H2N-LX-NH2 can be employed in the reaction to produce the polymer).

[0230] The spacer group Lx, in each repeat unit of formula (X), may be the same or different and may, for instance, be selected from unsubstituted or substituted C1-20 alkylene, C1-20 perfluoroalkylene, arylene, heteroarylene and -C1-20 alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 500, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, C1-6 alkyl and aryl. Often, each R” is independently selected from H, methyl and phenyl.

[0231] The spacer group Lxin each repeat unit of formula (X) may for instance be independently selected from unsubstituted or substituted C1-20 alkylene, arylene, heteroarylene and -C1-20 alkylene- (O-C1.20 alkylene-)mwherein m is 1 to 100, or m is 1 to 50, wherein each of said C1-20 alkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, C1-6 alkyl and aryl. Often, each R”is independently selected from H, methyl and phenyl.

[0232] Each spacer group Lxmay for instance independently be unsubstituted or substituted C1-20 alkylene, arylene, heteroarylene or -C1-20 alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, wherein each of said C1-20 alkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, C1-6 alkyl and aryl. Often, each R” is independently selected from H, methyl and phenyl.

[0233] Each spacer group Lxmay for instance independently be unsubstituted or substituted C1-20 alkylene, arylene, heteroarylene or -C1-20 alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 10 (or for instance m is 1 to 6), wherein each of said C1-20 alkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, C1-6 alkyl and aryl. Often, each R” is independently selected from H, methyl and phenyl.

[0234] Each spacer group Lxmay for instance independently be unsubstituted or substituted C1-20 alkylene, arylene, heteroarylene or -C1-20 alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 500. Often, m is 1 to 100, for instance 1 to 50, or 1 to 20, or for example, 1 to 10, for instance 1 to 6. The integer m may, for instance, be 3, 4 or 5, for instance 3 or 4. Usually, the C1-20 alkylene groups of -C1-20 alkylene-(0-Ci-2o alkylene-)mare not interrupted by N(R”), O, S or arylene. Also, the C1-20 alkylene groups of -Ci-20 alkylene-(0-Ci-2o alkylene-)mare often unsubstituted. Usually, the C1-20 alkylene group is not interrupted by N(R”), O, S or arylene. Often, the C1-20 alkylene group is unsubstituted.

[0235] Each spacer group Lxis often, for instance, independently selected from unsubstituted C1-6 alkylene, for instance ethylene (i.e. -CH2-CH2-) or propylene (i.e. -CH2-CH2-CH2- or -CH2-CH(CH3)-).

[0236] The spacer group Lxmay for instance be unsubstituted arylene, for instance phenylene.

[0237] Preferably, however, the spacer group Lxis polypropylene glycol (PPG) or polyethylene glycol (PEG). Thus, for instance, each Lxmay be -CH2-CH2-(O-CH2-CH2-)mor -CH(CH3)-CH2-(O-CH2-CH(CH3)-)mor -CH2-CH(CH3)-(O-CH2-CH(CH3)-)m. Polymers comprising repeat units of formula (X), (X’) or (X”) in which Lxis such a PPG or PEG spacer group can be synthesised using, for example, polypropylene glycol) bis(2 -aminopropyl ether) or polyethylene glycol) bis(amine) as the diamino starting material for the spacer group.

[0238] Each spacer group Lxmay for instance be independently selected from: unsubstituted Ci-6 alkylene, for instance ethylene (i.e. -CH2-CH2-) or propylene (i.e. -CH2-CH2-CH2- or -CH2-CH(CH3)-); unsubstituted arylene, for instance phenylene; polypropylene glycol (PPG) and polyethylene glycol (PEG), for instance -CH2-CH2-(O-CH2-CH2-)mor -CH(CH3)-CH2-(O-CH2-CH(CH3)-)mor -CH2-CH(CH3)-(O-CH2-CH(CH3)-)m.

[0239] Thus, often, when the crosslinker compound is a polymer comprising repeat units of formula (X), (X’) or (X”):

[0240] E is a hydrazone group of formula (A), usually wherein R1is -S(O)2R2, and optionally wherein R2is para-tolyl; and

[0241] Lxis unsubstituted or substituted C1-20 alkylene, C1-20 perfluoroalkylene, arylene, heteroarylene or -C1-20 alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 500, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R”is independently selected from H, C1-6 alkyl and aryl. Lxmay for instance be polypropylene glycol (PPG), polyethylene glycol (PEG), unsubstituted C1-6 alkylene (for instance ethylene or propylene), or unsubstituted phenylene.

[0242] When Lxis polypropylene glycol (PPG) or polyethylene glycol (PEG) (for instance -CH2- CH2-(O-CH2-CH2-)mor -CH(CH3)-CH2-(O-CH2-CH(CH3)-)mor -CH2-CH(CH3)-(O-CH2-CH(CH3)- )m), the molecular weight (Mn) of Lxis typically from 100 Da to 50,000 Da, for instance from 200 Da to 30,000 Da, or for instance from 200 Da to 10,000 Da. The molecular weight (Mn) of Lxmay for instance be from 200 Da to 5,000 Da, for instance from 200 Da to 2,000 Da, or from 200 Da to 1,000 Da. The molecular weight (Mn) of Lxmay for instance be from 200 Da to 500 Da, or for example from 200 Da to 300 Da.

[0243] Usually, the polymer comprising repeat units of formula (X) is a polymer comprising repeat units of formula (X’).

[0244] As mentioned above, polyimide polymers comprising repeat units of formula (X) (including formulae X’ and X”) may be produced by reacting a diamino compound EENTZ-NEE (wherein Lxis said spacer group) with one or more carbonyl bis(phthalic anhydride) compounds of formula (XA) to produce a polyimide polymer comprising repeat units of the following formula (XB) and then converting the central carbonyl group in each of the repeat units of formula (XB) into a carbene precursor group E, selected from a hydrazone group of formula (A), a diazo group of formula (B), and a diazirine group of formula (C).

[0245] Reaction of the diamino compound H2N-LX-NH2 with the carbonyl bis(phthalic anhydride) compound of formula (XA) to produce the polyimide polymer comprising units of formula (XB) is a dehydrative condensation reaction which is typically carried out using the Dean-Stark method. Typically, in this method, an NMP (N-Methyl-2 -Pyrrolidone) solution of the carbonyl bis(phthalic anhydride) compound of formula (XA) is stirred, while a second NMP solution, containing an equimolar amount of the diamino compound H2N-LX-NH2, is added dropwise and the reaction solution is stirred overnight at room temperature. Toluene is then added and the reaction mixture is heated to 170 °C under Dean-Stark conditions (i.e. using Dean-Stark apparatus to remove the water generated by the reaction). The mixture is then cooled to room temperature and the product - the polyimide polymer comprising units of formula (XB) - is precipitated into methanol.

[0246] Alternatively, the diamino compound H2N-LX-NH2 and the carbonyl bis(phthalic anhydride) compound of formula (XA) may be reacted to produce the polyimide polymer comprising units of formula (XB), by the “pre-polymer method”. Typically, in the pre-polymer method, a methanol solution of the carbonyl bis(phthalic anhydride) compound of formula (XA) is stirred at room temperature, while an equimolar amount of the diamino compound EENTA-NEE is added dropwise. The reaction solution is then stirred for 24 hours at room temperature. The methanol is then removed by rotary evaporation and the resulting “prepolymer” is then placed in an oven at 170 °C for 3 hours to complete the ring closing reaction and produce the polyimide polymer comprising units of formula (XB).

[0247] The resulting polyimide polymer comprising units of formula (XB) can then be converted into polymers of formula (X) in which E is a carbene precursor group of formula (A), (B) or (C) by converting each carbonyl group bridging two phthalimide groups in the polymer (i.e. the central carbonyl group in each of the repeat units of formula XB) into the relevant carbene precursor group.

[0248] The carbonyl groups can be converted into hydrazone groups of formula (A), for instance, by treating the polymer comprising repeat units of formula (XB) with a compound of formula H2N-NHR1 in the presence of heat, wherein R1is as defined above. The compound of formula H2N-NHR1may be hydrazine when R1is H, i.e. compound of formula H2N-NH2, or it may be a compound of formula H2N-N(H)S(O)2R2(when R1is -S(O)2R2) wherein R2is as defined above. Typically, the polymer comprising repeat units of formula (XB) is treated with H2N-NHR1in the presence of heat and a solvent. Any suitable solvent may be employed, for instance a polar protic solvent such as an alcohol. Typically, the solvent is methanol or ethanol. The reaction is carried out with heating, typically at the reflux temperature of the solvent used. For example, when the solvent is ethanol the reaction is suitably carried out at a temperature of 78 °C or higher, e.g. at a temperature of 80 °C. Typically, when R1is -S(O)2R2for instance tosyl, a few drops of concentrated sulfuric acid are also added to the reaction mixture before heating.

[0249] The carbonyl groups in the polymer comprising units of formula (XB) can be converted into diazo groups of formula (B) via hydrazone groups of formula (A). In other words, the central carbonyl groups in formula (XB) are first converted into hydrazone groups of formula (A), by the method described above (treating with a compound of formula H2N-NHR1in the presence of heat), and then the hydrazone groups of formula (A) are converted into diazo groups of formula (B).

[0250] The hydrazone groups of formula (A) can be converted into diazo groups of formula (B) by oxidation or elimination. Accordingly, in one embodiment the =N-NHR1hydrazone groups are converted into diazo groups, =N=N, by oxidation or elimination. In the cases where R1is -S(O)2R2, wherein R2is as defined above, an elimination reaction is performed. The elimination is typically achieved by treating the hydrazone compound with a basic compound such as an inorganic salt or a trialkylamine compound or, for instance the organic base l,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Usually, the inorganic salt is lithium hydroxide, sodium hydroxide or potassium hydroxide. Usually, the trialkylamine compound is triethylamine. DBU can be advantageous in certain applications as it is non-volatile. Typically, the treatment of the tosyl hydrazone compound with the base (for instance a trialkylamine compound) is carried out in the presence of a solvent. The solvent used is suitably a polar protic solvent such as an alcohol, for instance methanol or water. The treatment can be carried out with the tosyl hydrazone compound either in phase with the base, as a biphasic mixture, or as a suspension of tosyl hydrazone compound in a basic soloution.

[0251] In the case where R1is H, an oxidation reaction may be performed. Any suitable oxidant can be used to convert the hydrazone compound, in which Y is =N-NH2, into the corresponding diazomethane compound. Suitable oxidants include metal oxides, such as mercuric oxide, nickel peroxide, or hydrogen peroxide or chlorine (bleach). Typically, the oxidant is manganese oxide. More typically, this oxidation is conducted in the presence of a base, for instance a metal hydroxide and sodium sulphate. The metal hydroxide is typically an alkali metal hydroxide, for instance potassium hydroxide. A saturated solution of the metal hydroxide is generally used. The solvent used for the metal hydroxide is suitably a polar protic solvent such as an alcohol, for instance ethanol. The solvent used for the solution of the compound of formula (III) is suitably a polar aprotic solvent, for instance tetrahydrofuran (THF) or an ether.

[0252] The carbonyl groups in the polymer comprising units of formula (XB) can be converted into diazirine groups of formula (B) using known chemistry, for instance by using the procedure described in J. Am. Chem. Soc. 2020, 142, 52, 21743-21750. According to that procedure, the carbonyl groups, C=O in the polymer are first converted into N-tosyloxime groups, C=N-OTs. This is done by (i) treating the polymer with NFFOH’HCl in pyridine at 80 °C for 2 h, to convert the carbonyl groups C=O into oxime groups C=N(OH) and then (ii) treating the resulting oxime with p- toluenesulfonylchloride (tosyl chloride) and ethylamine in acetone at 0 °C, and then stirring at room temperature for 3 hours, to convert the oxime groups C=N(OH) into N-tosyloxime groups, C=N-OTs. The N-tosyloxime groups, C=N-OTs, in the resulting polymer are then converted into diaziridine groups by treating a diethyl ether solution of the polymer with liquid ammonia at -78 °C for 2 hours. Finally, the diaziridine groups in the resulting polymer are then converted into diazirine groups of formula (B) by treating a dichloromethane solution of the diaziridine -containing polymer with triethylamine and iodine at 0 °C for 30 minutes. The resulting diazirine polymer is then extracted using dichloromethane, dried using MgSCfi and purified.

[0253] Thus, the reacted crosslinker in the anion-conducting composite material is typically obtainable by generating carbene reactive intermediate groups from the carbene precursor groups in the polymer comprising repeat units of formula (X), i.e. the crosslinker compound, so that the carbene reactive intermediate groups react with the porous support material and the cationic polymer. The carbene reactive intermediate groups are highly reactive and are therefore capable of reacting with the porous support material, the cationic polymer and with the crosslinker compound itself (either intermolecularly, with another molecule of the crosslinker compound, or intramolecularly with another moiety in the same molecule of the crosslinker compound), and with any other molecule or moiety present in the composition. In this way, a cross-linked network comprising the cationic polymer and the reacted crosslinker is formed which is bonded to the porous support material.

[0254] Accordingly, the reacted crosslinker is typically a polymer comprising repeat units of formula (XX) wherein Lxis a spacer group;

[0255] C is a carbon atom; and

[0256] * is a point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition.

[0257] Lxmay be as further defined anywhere herein for the polymer comprising repeat units of formula (X).

[0258] The other molecule or moiety in the composition may be another molecule or moiety of the reacted crosslinker. Alternatively, the other molecule or moiety in the composition may be a further cationic compound, for instance a cationic small molecule, or a further cationic polymer (where more than one type of cationic polymer is present in the composition). Alternatively, the other molecule or moiety in the composition may be a further reacted crosslinker, where more than one type of reacted crosslinker is present in the composition.

[0259] Preferably, the reacted crosslinker is a polymer comprising repeat units of formula (XX’) wherein Lxis said spacer group;

[0260] C is a carbon atom; and

[0261] * is a point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition.

[0262] Alternatively, the reacted crosslinker may be a polymer comprising repeat units of formula (XX”) wherein Lxis said spacer group;

[0263] C is a carbon atom; and

[0264] * is a point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition.

[0265] Alternatively, the reacted crosslinker may be a polymer comprising repeat units of formula (XX’) and repeat units of formula (XX”).

[0266] In each of these embodiments the spacer group Lxmay be as further defined anywhere herein.

[0267] Crosslinker compounds comprising a repeat unit of formula (X) are not the only crosslinker compounds that may be employed in the present invention. A wide range of alternative crosslinker compounds having 3 or more carbene or nitrene precursor groups, which may be employed as the crosslinker compound in the present invention, are disclosed in WO 2010 / 100410 Al and WO 2010 / 100413 A2, and in their priority documents GB 0903563.5 and GB 0914692.9. The entire contents of each of WO 2010 / 100410 Al, WO 2010 / 100413 A2, and their priority applications GB 0903563.5 and GB 0914692.9, are hereby incorporated herein by reference.

[0268] Accordingly, the reacted crosslinker in the anion-conducting composite material of the present invention may be obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound of formula (II) wherein:

[0269] Q is a core moiety, a polymer or a dendrimer; n is an integer equal to or greater than 3; each L, which is the same or different, is a single bond or a linker group; each R, which is the same or different, is a terminal group; and each E, which is the same or different, is one of said reactive intermediate precursor groups, wherein: x is 1 and E is a carbene precursor group independently selected from a hydrazone group of formula (A), a diazo group of formula (B) and a diazirine group of formula (C), or x is 0 and E is a nitrene precursor group which is an azide group of formula (D): wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group. The crosslinker compound of formula (II) as defined above comprises n groups of the following formula, which are bonded to the core moiety, dendrimer or polymer Q: and therefore n reactive intermediate precursor groups, E, wherein n is an integer equal to or greater than 3. The n reactive intermediate precursor groups, E, are the same or different, i.e. they may differ from one (R)x-E-L- group to the next. Similarly, the linker groups (or single bonds) L, the integer x and / or the terminal groups R, when present, may differ from one (R)x-E-L- group to the next in the crosslinker compound of formula (II). For instance, the crosslinker compound of formula (II) may comprise a first group of formula (R)x-E-L-, a second group of formula (R)x-E-L-, and a third group of formula (R)x-E-L-, wherein the reactive intermediate precursor groups, E, the linker groups (or single bonds) L, the integer x and / or the terminal groups R are different in each of the first, second and third (R)x-E-L- groups. Typically, however, E is the same reactive intermediate precursor group in all of the (R)x-E-L- groups in the crosslinker compound of formula (II). Similarly, L is typically the same in all of the (R)x-E-L- groups in the crosslinker compound of formula (II). Similarly, R is typically the same terminal group in all of the (R)x-E-L- groups in the compound of formula (II), and / or x is the same integer in all of those groups.

[0270] The number of (R)x-E-L- groups (and hence the number of reactive intermediate precursor groups E) in the crosslinker compound of formula (II), n, is an integer equal to or greater than 3. Often, however, n is greater than or equal to 4.

[0271] In one embodiment, n is an integer of from 3 to 50, more typically an integer of from 3 to 20, or from 3 to 10, or an integer of 3, 4 or 5.

[0272] In other embodiments, however, n is an integer of from 3 to 500, and is more typically an integer of from 3 to 200, from 3 to 100, or from 10 to 100, for instance from 10 to 50.

[0273] In yet another embodiment, n is an integer equal to or greater than 50, for instance equal to or greater than 100. Thus, n may be an integer of from 50 to 1,000,000, from 50 to 100,000, from 50 to 10,000, from 50 to 5,000, or from 50 to 1,000. More typically, in this embodiment, n is an integer of from 50 to 1,000.

[0274] As discussed above, each E may be a carbene precursor group independently selected from a hydrazone group of formula (A), a diazo group of formula (B) and a diazirine group of formula (C), in which case x is 1, or a nitrene precursor group which is an azide group of formula (D), in which case x is 0. Thus, the n (at least 3) (R)x-E-L- groups in formula (II) may be independently selected from groups of the following formulae (A’), (B’), (C’) and (D’): wherein R, L and R1are as defined above for the compound of formula (II).

[0275] The n reactive intermediate precursor groups employed in the crosslinker compound of formula (II) may be nitrene precursor groups, i.e. azide groups of formula (D). Thus, each E may be an azide group of formula (D), in which case x is 0, and each (R)x-E-L- group in formula (II) is a group of the formula (D’) wherein L is as defined above for the crosslinker compound of formula (II).

[0276] More typically, however, the n reactive intermediate precursor groups employed in the crosslinker compound of formula (II) are carbene precursor groups. Thus, each E may be selected from hydrazone groups of formula (A), a diazo group of formula (B) and a diazirine group of formula (C), in which case x is 1 and each (R)x-E-L- group in formula (II) is a group of the formula (A’), (B’) or (C’) wherein R, L and R1are as defined above for the crosslinker compound of formula (II).

[0277] Each E may for instance be selected from hydrazone groups of formula (A) and a diazo group of formula (B), in which case x is 1 and each (R)x-E-L- group in formula (II) is a group of the formula

[0278] (A’) or (B’) wherein R, L and R1are as defined herein for the crosslinker compound of formula (II).

[0279] Thus, often, the crosslinker compound of formula (II) is a compound of formula (A”) or a compound of formula (B”) wherein n, R, L and R1are as defined herein for the crosslinker compound of formula (II).

[0280] More typically, however, each E is selected from hydrazone groups of formula (A), in which case x is 1 and each (R)x-E-L- group in formula (II) is a group of the formula (A’) wherein R, L and R1are as defined herein for the crosslinker compound of formula (II).

[0281] Thus, the crosslinker compound of formula (II) is more typically a compound of formula (A”) wherein n, R, L and R1are as defined herein for the crosslinker compound of formula (II).

[0282] In the hydrazone groups of formula (A), (A’) and (A”) in the crosslinker compound of formula (II), R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group.

[0283] Often, R1is H.

[0284] However, hydrazone groups of formula (A) in which R1is -S(O)2R2are often preferred.

[0285] Typically, R2is an unsubstituted or substituted Ci-6 alkyl group, an unsubstituted or substituted phenyl group, or an unsubstituted or substituted naphthyl group. Often, R2is Ci-6 alkyl, phenyl or naphthyl, which phenyl or naphthyl is unsubstituted or substituted with Ci-6 alkyl, di(Ci-e alkyl)amino, hydroxyl, nitro, cyano or methoxy.

[0286] More typically, R2is Ci-6 alkyl, phenyl or naphthyl, which phenyl or naphthyl is unsubstituted or substituted with Ci-6 alkyl or di(Ci-e alkyl)amino.

[0287] Typically, R1is -S(O)2R2wherein R2is phenyl substituted with Ci-6 alkyl. More typically, R1is -S(O)2R2wherein R2is phenyl substituted with methyl (i.e. tolyl). Thus, often, R1is a tosyl group. In another embodiment, R1is H. The nature of the terminal groups, R, in the crosslinker compound of formula (II) is not critical. However, the reactivity of the crosslinker compound and its derived reactive intermediate (e.g. carbene reactive intermediate) can be modified by including electron releasing or electron withdrawing groups within the terminal group R. In addition, the solubility of the crosslinker compound of formula (II) and its derived reactive intermediate (e.g. carbene or nitrene reactive intermediate) can be modified by including groups of a given hydrophilicity or lipophilicity within the terminal group R. When R is an aryl or heteroaryl group, the reactivity of the compound and its derived reactive intermediate can be modified by including electron releasing or electron withdrawing groups on the aromatic ring. In addition, the solubility of the compound and its derived reactive intermediate can be modified by including groups of a given hydrophilicity or lipophilicity on the aromatic ring.

[0288] Accordingly, in the crosslinker compound of formula (II), each R, which is the same or different, is typically selected from hydrogen, aryl, heteroaryl, C1-20 perfluoroalkyl, Ci-w alkoxy, aryloxy, di(Ci-io)alkylamino, alkylarylamino, diarylamino, C1-10 alkylthio, arylthio and CR’s, wherein each R’ is independently selected from a halogen atom, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, heteroaryl, C3-20 carbocyclyl, C3-20 heterocyclyl, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl, triarylsilyl, C2-20 alkenyl, C2-20 alkynyl and C1-20 alkyl, which C1-20 alkyl and C1-20 perfluoroalkyl are optionally interrupted by N(R”), O, S or arylene wherein R” is H, C1-6 alkyl or aryl; provided that when R is aryl or heteroaryl said aryl or heteroaryl may be unsubstituted or substituted by one, two, three, four or five groups (more typically, one two or three groups, for instance one or two groups, or one group), which groups are the same or different and typically are independently selected from C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, cyano, nitro, hydroxy, halo, carboxy, amino, C1.10 alkylamino, di(Ci. io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acyl, acyloxy, acylamido, ester, C1-10 alkoxy, aryloxy, haloalkyl, thiol, C1-10 alkylthio, arylthio, sulfonic acid, sulfonyl, sulfonamide, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl and triarylsilyl.

[0289] More typically, each R, which is the same or different, is aryl or heteroaryl, which aryl or heteroaryl is unsubstituted or substituted by one, two, three, four or five groups (more typically, one two or three groups, for instance one or two groups, or one group), which groups are the same or different and typically are independently selected from C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, cyano, nitro, hydroxy, halo, carboxy, amino, Ci- 10 alkylamino, di(Ci-io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acyl, acyloxy, acylamido, ester, Ci-w alkoxy, aryloxy, haloalkyl, thiol, C1-10 alkylthio, arylthio, sulfonic acid, sulfonyl, sulfonamide, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl and triarylsilyl. Often, for instance, each R, which is the same or different, is phenyl which is unsubstituted or substituted by one, two, three, four or five groups (more typically, one two or three groups, for instance one or two groups, or one group), which groups are the same or different and typically are independently selected from C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, cyano, nitro, hydroxy, halo, carboxy, amino, CMO alkylamino, di(Ci. io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acyl, acyloxy, acylamido, ester, CMO alkoxy, aryloxy, haloalkyl, thiol, CMO alkylthio, arylthio, sulfonic acid, sulfonyl, sulfonamide, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl and triarylsilyl.

[0290] The nature of the groups L in the crosslinker compound of formula (II) is also not critical. Any suitable linking group may be employed or L may be a single bond.

[0291] Typically, however, each L, which is the same or different, is a single bond or a group of formula (XII) wherein:

[0292] A1is bonded to E, wherein, when E is a carbene precursor group and x is 1, A1is bonded to the carbon atom bonded to R, and when E is a nitrene precursor group and x is 0, A1is bonded to an azide group of formula (D), wherein A1is: a single bond or an unsubstituted or substituted group selected from arylene, heteroarylene, C1-20 perfluoroalkylene, *-0-Ci-2o alkylene, *-0-Ci-2o perfluoroalkylene, *-O-arylene, *-O- heteroarylene, *-N(R”)-CI-2O alkylene, *-N(R”)-CI-2O perfluoroalkylene, *-N(R”) -arylene, *-N(R”)- heteroarylene, *-S-Ci-2o alkylene, *-S-Ci-2o perfluoroalkylene, *-S-arylene, *-S-heteroarylene, *- C(R’)2-CI-2O alkylene, *-C(R’)2-CI-2O perfluoroalkylene, *-C(R’)2-arylene, *-C(R’)2-heteroarylene and C1-20 alkylene, wherein each R’ is independently selected from a halogen atom, C O haloalkyl, CMO fluoroalkyl, CMO perfluoroalkyl, aryl, heteroaryl, C3-10 carbocyclyl, Cs-ioheterocyclyl, tri(Ci-io alkyl)silyl, aryldi(Ci-io alkyl)silyl, diaryl(Ci-io alkyl)silyl, triarylsilyl, C2-10 alkenyl, C2-10 alkynyl and CMO alkyl, wherein * is the point of attachment of A1to E, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein R” is independently selected from H, CM alkyl and aryl;

[0293] A2is a single bond or an unsubstituted or substituted group selected from C1-20 alkylene, C1-20 perfluoroalkylene, arylene, heteroarylene, *-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, *-Z1-Ci-2o alkylene, *-Z1-Ci-2o perfluoroalkylene, *-Z’-arylene, *-Z’ -heteroarylene and *-Z1-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, wherein Z1is selected from O, S, C(O), S(O), S(O)2, N(R”), C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein * is the point of attachment of A2to A1, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, CM alkyl and aryl; and A3is a single bond or an unsubstituted or substituted group selected from *-Z2-arylene, *-Z2- heteroarylene, *-Z2-CI-2O alkylene, arylene, heteroarylene, C1-20 alkylene, *-Z2-arylene-O, *-Z2- heteroarylene-O, *-Z2-CI-2O alkylene-O, *-arylene-O, *-heteroarylene-O, *-Ci-2o alkylene-O, C(O), S(O)2, *-OC(O), *-N(R”)C(O), O, S, N(R”), *-C(O)O, *-C(O)N(R”), *-S(O)2O, C1 20 alkenylene, Ci. 20 alkynylene, *-Z2-CI-2O alkenylene and *-Z2-CI-2O alkynylene, wherein Z2is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, Ci-e alkyl and aryl, and wherein * is the point of attachment of A3to A2.

[0294] Typically, at least one of A1, A2and A3is not a single bond. In particular, A1is typically not a single bond. Often, A1is an unsubstituted or substituted group selected from arylene and heteroarylene. Typically, A1is an unsubstituted or substituted arylene group. More typically, A1is an unsubstituted or substituted phenylene group, even more typically an unsubstituted phenylene group.

[0295] In another embodiment, however A1is a single bond.

[0296] Usually, A2is an unsubstituted or substituted group selected from C1-20 alkylene, C1-20 perfluoroalkylene, *-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, *-Z1-Ci-2o alkylene, *- Z’-Ci^o perfluoroalkylene and *-Z1-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, wherein Z1is selected from O, S, C(O), S(O), S(O)2, N(R”), C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein * is the point of attachment of A2to A1, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, C1-6 alkyl and aryl. More typically, A2is CMO alkylene or *-Ci-6 alkylene-(O-C2-4 alkylene-)mwherein m is 1 to 20 and wherein * is the point of attachment of A2to A1.

[0297] In one embodiment, A1is a phenylene group, typically an unsubstituted phenylene group, and A2is CMO alkylene or *-Ci-6 alkylene-(O-C2-4 alkylene-)mwherein m is 1 to 20 and wherein * is the point of attachment of A2to A1.

[0298] Typically, A3is a single bond, O, C(O), *-OC(O) or an unsubstituted or substituted group selected from * -Z2-arylene, * -Z2-heteroarylene, arylene, heteroarylene, * -Z2-arylene-O, *-Z2- heteroarylene-O, *-arylene-0 and *-heteroarylene-O, wherein Z2is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, C1-6 alkyl and aryl, and wherein * is the point of attachment of A3to A2.

[0299] More typically, A3is a single bond, O, C(O), *-OC(O) or an unsubstituted or substituted group selected from *-O-arylene, *-O-heteroarylene, *-0-arylene-0 and *-0 -heteroarylene -O wherein * is the point of attachment of A3to A2. Even more typically, A3is a single bond, O, or an unsubstituted or substituted group selected from *-O-arylene, *-O-heteroarylene, *-0-arylene-0 and *-0 -heteroarylene -O wherein * is the point of attachment of A3to A2. Even more typically, A3is a single bond, O, or an unsubstituted or substituted group selected from * -O-heteroarylene and *-O- heteroarylene-0 wherein * is the point of attachment of A3to A2. In one embodiment A1, A2and A3are all single bonds, which means that L is itself a single bond. Thus, in some embodiments, L is a single bond and each of the reactive intermediate precursor functionalities, E, is bonded directly to Q.

[0300] For instance in some embodiments, wherein the crosslinker compound of formula (II) comprises hydrazone groups of formula (A) in which R1is -S(O)2R2(i.e. sulfonylhydrazone groups), L may be a single bond. In such embodiments, the carbon atoms of the carbene precursor groups (which carbon atoms are bonded to R) are bonded directly to Q.

[0301] Q is a core moiety, a polymer or a dendrimer. The core moiety, polymer or dendrimer is functionalised with said n groups of formula (R)x-E-L- in said crosslinker compound of formula (II). As is shown in formula (II), each of the n reactive intermediate precursor groups E is bonded to the core moiety, polymer or dendrimer, Q, via the group L, which may be a linking group or a single bond. When L is a group of formula (XII) as defined above, each of the n reactive intermediate precursor groups is typically bonded to the core moiety, polymer or dendrimer, Q, via group A3of said group of formula (XII).

[0302] As is described in detail in WO 2010 / 100410 Al, and in the priority documents of WO 2010 / 100410 Al, GB 0903563.5 and GB 0914692.9, the crosslinker compounds of formula (II) may be synthesised by coupling the reactive intermediate precursor groups (or carbonyl precursors thereto) to a core moiety, polymer or dendrimer Q’ by reaction between a functional group on the linker moiety of the reactive intermediate precursor group (or on the carbonyl precursor thereto) with functional groups, -A4-X2on Q’. Thus, the core moiety, polymer or dendrimer Q of the crosslinker compound of formula (II) is typically attached to the groups L of the n reactive intermediate precursor groups via n linker groups of formula A4.

[0303] Accordingly, Q in the crosslinker compounds of formula (II) is typically a core moiety, a polymer or a dendrimer which comprises n linker groups of formula A4, each of which is attached to a group L, wherein n is an integer equal to or greater than 3. Each individual A4is the same as or different from the others and is independently selected from a single bond, -Z3-arylene-*, -Z3- heteroarylene-*, -Z3-CI-2O alkylene-*, arylene, heteroarylene, C1-20 alkylene, -Z3-arylene-O-*, -Z3- heteroarylene-O-*, -Z3-CI-2O alkylene-O-*, arylene-O-*, heteroarylene-O-*, C1-20 alkylene-O-*, -C(O)- *, S(O)2, -OC(O)-*, -N(R”)C(O)-*, O, S, N(R”), -C(O)O-*, -C(O)N(R”)-*, -S(O)2O-*, C1 20 alkenylene, C1-20 alkynylene, -Z3-CI-2O alkenylene-* and -Z3-CI-2O alkynylene-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, C1-6 alkyl and aryl, and wherein * is the point of attachment of A4to L.

[0304] In one embodiment, each A4is independently selected from O, arylene-O-*, heteroarylene -O- *, C1-20 alkylene-O-*, -Z3-arylene-O-*, -Z3-heteroarylene-O-*, -Z3-CI-2O alkylene-O-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, wherein * is the point of attachment of A4to L. More typically, in this embodiment, A4is O.

[0305] In another embodiment, each A4is independently selected from a single bond, -Z3-arylene-*, - Z3-heteroarylene-*, -Z3-C 1-20 alkylene-*, arylene, heteroarylene, C1-20 alkylene, -C(O)-, S(O)2, - OC(O)-*, -N(R”)C(O)-*, C1-20 alkenylene, C1-20 alkynylene, -Z3-CI-2O alkenylene-* and -Z3-CI-2O alkynylene-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, and wherein * is the point of attachment of A4to L.

[0306] In a further embodiment, A4is -C(O)-.

[0307] In another embodiment, A4is -Z3-heteroarylene-* wherein * is the point of attachment of A4to L. Typically, Z3is O. Typically, in this embodiment, A4is a group of formula (XIX) wherein * is the point of attachment to L and wherein XLis halo, hydroxyl, CMO alkoxy, C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, aryl, aralkyl, cyano, amino, CMO alkylamino, di(Ci-io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, C1-20 haloalkyl, ester, acyl, acyloxy, aryloxy, nitro, carboxy, sulfonic acid, sulfonyl, sulphonamide, thiol, C O alkylthio or arylthio.

[0308] Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro.

[0309] In one embodiment, Q is a dendrimer, which dendrimer comprises n surface groups which are linker groups of formula A4as defined above. The n linker groups A4are the same as or different from one another and bonded to the n L groups of the n carbene precursor groups [R]x-E-L- in said crosslinker compound of formula (II). Any suitable dendrimer structure may be employed. When Q is a dendrimer, n is typically an integer of from 3 to 500, or from 4 to 500, and is more typically an integer of from 3 to 200, or from 4 to 200, from 3 to 100, or from 4 to 100, or from 10 to 100, for instance from 10 to 50.

[0310] Any suitable dendrimer may be used. PAMAM dendrimers are suitable, for instance.

[0311] When Q comprises a polymer, the polymer may be a linear polymer, a branched polymer or a hyperbranched polymer. The polymer may for instance be a homopolymer or a copolymer. The copolymer may be a ter-polymer or any other multiple combination polymer. Suitable copolymers include polymethylmethacrylate-co-poly-2 -dimethylamino ethyl methacrylate, for instance.

[0312] Also covered are different polymer acrhitectures, including but not limited to branched polymers; block copolymers, for instance, SBS rubber (Kraton), or EO-PO-EO (Pluronic); star polymers (Tetronic); or hyperbranced polymers (PEI). Polymers of different molecular weight ranges are also covered, from small macromers with a repeat unit length of a dimer, to polymers with a molecular weight of millions. The degree of polymerisation, Dp, of the polymer (i.e. the polymer molecular weight divided by the molecular weight of the repeat unit) may be from 2 to 100,000,000.

[0313] Typically, the polymer employed is either soluble or dispersable.

[0314] When Q comprises a polymer, the polymer may be a homo-polymer or a copolymer.

[0315] In one embodiment, when Q comprises a polymer, the polymer is selected from any of the polymers listed in the following paragraph and their copolymers. Thus, the polymer may be a homopolymer comprising any of the following polymers, or a copolymer which comprises the monomeric units of any one or more of the following polymers:

[0316] Condensation polymers and Addition polymers. Polysaccharides, including but not limited to chitin, guar gums, gum arabic, galactomannans, for instance locust bean gum (LBG). Proteins, including but not limited to Keratin. Polyesters, including but not limited to Nylon, polyethylene terephthalate (PET), polyoxyethylene terephthalate (POET) or a copolymer of polyethylene terephthalate and polyoxyethylene terephthalate (PET-POET). Polyethers, including but not limited to polypropylene glycol (PPG), polyethylene gloycol (PEG), Polyethylene oxide (PEO). Polyolefins, including but not limited to polyethylene (PE), polypropylene (PP), and co-polymers thereof. Polyolefin co-polymers. Polyacrylates and polymethacrylates, including but not limited to polyacric acid (PAA) polymethacrylic acid (PMAA), Poly2 -dimethylamino methacrylate (PDMAEMA), Poly- 2-hydroxyethyl methacylate (PHEMA), acrylonitrile. Polystyrene. Thermoplatic elastomers, including but not limited to, Polybutadiene, Polyisoprene, SBS rubber and SIS rubber. Polycarbonates. Polyetheretherketone (PEEK). Polyetherimides. Polyimides. Polysulfones. Poly vinyl chloride (PVC). Polysilanes. Polysiloxanes. Polyureas. Polyurethanes. Polylactic acid. Polyvinylidene chloride. Fluoro-polymers, including but not limited to PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxy polymer resin), fluorinated ethylene -propylene and PVDF (Kynar). Polyethylene imines.

[0317] When Q comprises a polymer, the polymer may be a salt of any of the polymers described herein.

[0318] In some embodiments, when Q comprises a polymer, the polymer comprises a polysaccharide, a protein, a polyester, a polyether, a polyacrylate, a polymethacrylate, a polycarbonate, polyetheretherketone (PEEK), a polyetherimide, a polyimide, a polysulfone, poly(vinyl chloride), a polysilane, a polysiloxane, a polyurea, a polyurethane, polylactic acid, polyvinylidene chloride, a fluoro-polymer, a polyethylene imine, or a salt thereof.

[0319] Typically, the polymer is one that has a functionality -A4-X2as defined herein and in WO 2010 / 100410 Al, for instance an OH, NH, SH or aryl (typically phenyl) functionality that allows single step transformation to introduce the [R]x-E-L- groups containing the reactive intermediate precursor groups E (or carbonyl precursors thereof) onto the polymer. Alternatively, however, any polymer can be modified to include the reactive intermediate precursor group using a two-step process. In such a process, an -A4-X2functionality, for instance an - OH, NH, SH or aryl (typically phenyl) functionality is first reacted onto the desired polymer. Subsequently, that -A4-X2functionality, which has been newly-introduced on the polymer, is coupled with a further compound, which comprises the reactive intermediate precursor group of formula (I), to introduce that reactive intermediate precursor group onto the polymer.

[0320] Thus, when Q comprises a polymer, for instance any of the polymers defined above, the polymer typically comprises n linker groups of formula A4which are the same or different and are as defined above, each of which is attached to a group L of a reactive intermediate precursor group of formula (I), wherein n is an integer equal to or greater than 2.

[0321] In one embodiment, A4is O or -Z3-heteroarylene-* wherein * is the point of attachment of A4to L. Typically, Z3is O. More typically, in this embodiment, A4is O or a group of formula (XIX) as defined above.

[0322] In one embodiment, Q comprises a polysaccharide, a polyester or polystyrene.

[0323] In one embodiment, when Q comprises a polysaccharide, the polysaccharide is a chitin, guar gum, gum arabic, or a galactomannan, for instance locust bean gum (LBG).

[0324] In one embodiment, when Q comprises a polyester, the polyester is Nylon, polyethylene terephthalate (PET), polyoxyethylene terephthalate (POET) or a copolymer of polyethylene terephthalate and polyoxyethylene terephthalate (PET-POET).

[0325] As mentioned above, in some embodiments of the crosslinker compound of formula (II), L may be a single bond.

[0326] Typically, when L is a single bond, Q comprises at least n aryl or heteroaryl rings, wherein each L which is single bond is attached directly to a said aryl or heteroaryl ring of Q. The single bond, L, thereby bonds the aryl or heteroaryl ring directly to the carbon atom of the carbene precursor group (i.e. the carbon atom that is also bonded to R in the crosslinker compound of formula II) or to the nitrogen atom of the nitrene precursor group (azide group). In this embodiment Q is a core moiety, polymer or dendrimer that comprises said n aryl or heteroaryl rings. Typically, said aryl or heteroaryl rings are aryl rings. Usually, said aryl rings are phenyl rings. Examples of polymers that comprise aryl rings include, for instance, polystyrene, a copolymer comprising polystyrene, a thermoplastic elastomer, polyisoprene, a copolymer comprising polyisoprene, SBS rubber, SIS rubber or poly (styrene) -poly(ethylene / butylene) -poly( styrene) ( SEB S) .

[0327] More typically, when L is a single bond, Q is a polymer which comprises at least n aryl or heteroaryl rings, wherein each L which is single bond is attached directly to a said aryl or heteroaryl ring, thereby bonding the aryl or heteroaryl ring directly to the carbon atom which is bonded to R. Typically, said aryl or heteroaryl rings are aryl rings. Typically, said aryl rings are phenyl rings.

[0328] Thus, in some embodiments of the crosslinker compound of formula (II), L is a single bond and Q is a polymer which comprises at least n aryl or heteroaryl rings, wherein each L which is single bond is atached directly to a said aryl or heteroaryl ring, thereby bonding the aryl or heteroaryl ring directly to the carbon atom which is bonded to R. Typically, said aryl or heteroaryl rings are aryl rings. Typically, said aryl rings are phenyl rings. Usually, in such embodiments, Q comprises polystyrene, a copolymer comprising polystyrene, a thermoplastic elastomer, polyisoprene, a copolymer comprising polyisoprene, SBS rubber, SIS rubber or poly( styrene) - poly(ethylene / butylene)-poly( styrene) (SEBS).

[0329] Typically, when Q comprises a polymer, n is an integer equal to or greater than 50, for instance equal to or greater than 100. Thus, n may be an integer of from 50 to 1,000,000, from 50 to 100,000, from 50 to 10,000, from 50 to 5,000, or from 50 to 1,000. More typically, in this embodiment, n is an integer of from 50 to 1,000.

[0330] In one embodiment, Q in the crosslinker compound of formula (II) is a core moiety which is a straight-chained or branched, saturated or unsaturated C1-20 hydrocarbon moiety; an aryl ring; a heteroaryl ring; a C5-10 carbocyclic ring; a C5-10 heterocyclic ring; or a fused bi-, tri- or tetracyclic ring system wherein each ring of said fused bi-, tri- or tetracyclic ring system is independently selected from an aryl ring, a heteroaryl ring, a C5-10 carbocyclic ring and a C5-10 heterocyclic ring; wherein said hydrocarbon moiety, aryl ring, heteroaryl ring, carbocyclic ring, heterocyclic ring or fused bi-, tri- or tetracyclic ring system is substituted with said n linker groups, A4, and is otherwise unsubstituted or substituted, wherein each A4is the same or different and is as defined hereinbefore and wherein each A4is attached to a group L.

[0331] Typically, when Q is a core moiety, n is an integer of from 3 to 50, or from 4 to 50, more typically an integer of from 3 to 20, or from 4 to 20, or from 3 to 10, or from 4 to 10, or an integer of 3, 4 or 5.

[0332] Typically, n is an integer of from 3 to 10 and Q is a core moiety of formula (XIV): wherein each A4is the same or different and is as defined above, and wherein A is an aryl ring, a heteroaryl ring, a C5-10 carbocyclic ring, a C5-10 heterocyclic ring, or a fused bi-, tri- or tetracyclic ring system wherein each ring of said fused bi-, tri- or tetracyclic ring system is independently selected from an aryl ring, a heteroaryl ring, a C5-10 carbocyclic ring and a C5-10 heterocyclic ring.

[0333] Typically, in this embodiment, A is an aryl ring or a heteroaryl ring.

[0334] Typically, n is an integer of from 3 to 6.

[0335] In another embodiment, n is an integer of from 3 to 10 and Q is a core moiety of formula (XVI): wherein each A4is the same or different and is as defined above, and wherein AHCis straight-chained or branched, saturated or unsaturated C1-20 hydrocarbon moiety which is otherwise unsubstituted or substituted.

[0336] Typically, in this embodiment, n is an integer of from 3 to 6.

[0337] Typically, the C1-20 hydrocarbon moiety is a straight-chained or branched Ci -10 hydrocarbon moiety which is substituted with said n A4linkers and is otherwise unsubstituted or substituted. For instance, it may be a methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane or decane moiety which is substituted with said n A4linkers and otherwise unsubstituted or substituted. The hydrocarbon may be straight-chained or branched. Thus, for instance, a propane hydrocarbon moiety may be i-propane or n-propane and a butane moiety may be t-butane, s-butane, i-butane or n- butane.

[0338] In one embodiment, n is 3.

[0339] In one embodiment, n is 3 and Q is a core moiety of formula (XlVa) wherein each A4is the same or different and is as defined hereinbefore and wherein A is an aryl or heteroaryl ring. Typically, in this embodiment, each A4is independently selected from C(O), O, arylene-O-*, heteroarylene-O-*, C1-20 alkylene-O-*, -Z3-arylene-O-*, -Z3-heteroarylene-O-*, -Z3- C1.20 alkylene-O-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, C1-6 alkyl and aryl, wherein * is the point of attachment of A4to L. More typically, in this embodiment, each A4is independently selected from C(O) and O. Even more typically, in this embodiment, A4is C(O).

[0340] In another embodiment, n is 3 and Q is a core moiety of formula (XVIa) wherein A4is the same or different and is as defined hereinbefore and wherein q, m and p are the same or different and are independently selected from 0 and an integer of 1 to 20. Typically, in this embodiment, each A4is independently selected from C(O), O, arylene-O-*, heteroarylene -O-*, C1-20 alkylene-O-*, -Z3-arylene-O-*, -Z3-heteroarylene-O-*, -Z3-CI-2O alkylene-O-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, wherein * is the point of attachment of A4to L. More typically, in this embodiment, each A4is independently selected from C(O) and O. Even more typically, in this embodiment, A4is O.

[0341] In another embodiment, n is 3 and Q is any one of the following core moieties:

[0342] In one embodiment of the crosslinker compound of formula (II), L is a group of formula (XII) as defined above, in which A3is a single bond or an unsubstituted or substituted group selected from *-Z2-arylene, *-Z2-heteroarylene, *-Z2-C 1-20 alkylene, arylene, heteroarylene, C1-20 alkylene, C(O), S(O)2, *-OC(O) and *-N(R”)C(O), wherein Z2is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, and wherein * is the point of attachment of A3to A2.

[0343] Typically, in this embodiment, A3is a single bond.

[0344] Alternatively, A3may be an unsubstituted or substituted group selected from * -O-arylene and *-0 -heteroarylene wherein * is the point of attachment of A3to A2. For instance, A3may be a group of formula (XVII) wherein * is the point of attachment of A3to A2, and wherein XLis halo, hydroxyl, CMO alkoxy, C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, aryl, aralkyl, cyano, amino, CMO alkylamino, di(Ci-io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, C1-20 haloalkyl, ester, acyl, acyloxy, aryloxy, nitro, carboxy, sulfonic acid, sulfonyl, sulphonamide, thiol, CMO alkylthio or arylthio.

[0345] Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro.

[0346] Typically, when A3is an unsubstituted or substituted group selected from * -O-arylene and *- O-heteroarylene, A1is unsubstituted or substituted phenylene and A2is an unsubstituted or substituted group selected from C1-20 alkylene, C1-20 perfluoroalkylene, *-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, *-Z1-Ci-2o alkylene, *-Z1-Ci-2o perfluoroalkylene and *-Z1-Ci-2o alkylene-(O-Ci- 20 alkylene-)mwherein m is 1 to 20, wherein Z1is selected from O, S, C(O), S(O), S(O)2, N(R”), C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein * is the point of attachment of A2to A1, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, Ci-6 alkyl and aryl. More typically, in this embodiment, A1is unsubstituted or substituted phenylene and A2is CMO alkylene or *-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20 and wherein * is the point of attachment of A2to A1. Even more typically A2is *-Ci-6 alkylene-(O-C2-4 alkylene-)mwherein m is 1 to 20 and wherein * is the point of attachment of A2to A1. Usually, in these embodiments, A3is a group of formula (XVII) wherein * is the point of attachment of A3to A2and wherein XLis as defined above. Thus, L may for instance be the following group: wherein * is the point of attachment of L to the carbon atom bonded to R and wherein XLis as defined above.

[0347] When A3is a single bond, A1is typically unsubstituted or substituted phenylene and A2is typically unsubstituted or substituted C1-20 alkylene, for instance unsubstituted or substituted CMO alkylene, unsubstituted or substituted C1.4 alkylene or CH2. Thus, L may for instance be the following group: wherein * is the point of attachment of L to the carbon atom bonded to R.

[0348] In another embodiment, when A3is a single bond, A1and A2are also single bonds and therefore L itself is a single bond. Typically, in this embodiment, each L is attached to a phenyl group of Q. Typically, in this embodiment, Q is a core moiety, polymer or dendrimer bearing phenyl groups, more typically a polymer bearing phenyl groups, for instance polystyrene.

[0349] Typically, when L is a group of formula (XII) as defined above, in which A3is a single bond or an unsubstituted or substituted group selected from * -Z2-arylene, *-Z2-heteroarylene, *-Z2-CI-2O alkylene, arylene, heteroarylene, C1-20 alkylene, C(O), S(O)2, *-OC(O) and *-N(R”)C(O), as defined above, or in which A3is as further defined in the preceding paragraphs, Q is a core moiety, polymer or dendrimer comprising n linker atoms which are oxygen atoms, wherein each of said oxygen atoms is attached to a group L. Typically, in this embodiment, Q is a polysaccharide. For instance Q may be chitin, a guar gum, gum arabic or a galactomannan, for instance locust bean gum (LBG). Such polysaccharides bear terminal OH groups which can be converted into said n linker atoms which are oxygen atoms.

[0350] Alternatively Q may be a core moiety of formula (XIV) or formula (XVI): wherein n is an integer of 3 to 10, wherein A and AHCare as defined above, and wherein each A4, which is the same or different, is independently selected from O, arylene-O-*, heteroarylene-O-*, Ci-20 alkylene-O-*, -Z3-arylene-O-*, -Z3-heteroarylene-O-*, -Z3-CI-2O alkylene-O-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, Ci-6 alkyl and aryl, wherein * is the point of attachment of A4to L.

[0351] Alternatively Q may be a core moiety of formula (XlVa) or formula (XVIa) wherein

[0352] A is an aryl or heteroaryl ring; q, m and p are the same or different and are independently selected from 0 and an integer of 1 to 20; and each A4, which is the same or different, is independently selected from O, arylene-O-*, heteroarylene-O-*, C1-20 alkylene-O-*, -Z3-arylene-O-*, -Z3-heteroarylene-O-*, -Z3-CI-2O alkylene-O- *, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, C1-6 alkyl and aryl, wherein * is the point of attachment of A4to L.

[0353] Q may for instance be any one of the following core moieties:

[0354] In another embodiment of the crosslinker compound of formula (II), L is a group of formula (XII) as defined above, in which A3is O, S, N(R”), *-C(O)O, *-C(O)N(R”), *-S(O)2O, C1.20 alkenylene, C1-20 alkynylene, *-Z2-CI-2O alkenylene or *-Z2-CI-2O alkynylene, wherein Z2is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, and wherein * is the point of attachment of A3to A2. Typically, in this embodiment, A3is O. Typically, in this embodiment, A1is unsubstituted or substituted phenylene. A2is typically any A2group as defined hereinbefore. However, A2is more typically C1-20 alkylene. Typically, therefore A1is unsubstituted or substituted phenylene, A2is C1-20 alkylene and A3is O. Thus, L may be the following group wherein * is the point of attachment of L to the carbon atom bonded to R.

[0355] Typically, in the embodiments defined in the preceding paragraph, Q is a core moiety, polymer or dendrimer which bears n linker groups, each of which is attached to a group L, which linker groups are of formula (XIX) wherein * is the point af attachment to L, and wherein XLis halo, hydroxyl, Ci-w alkoxy, C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, aryl, aralkyl, cyano, amino, CMO alkylamino, di(Ci-io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, C1-20 haloalkyl, ester, acyl, acyloxy, aryloxy, nitro, carboxy, sulfonic acid, sulfonyl, sulphonamide, thiol, CMO alkylthio or arylthio.

[0356] Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro. Thus, Q may be a polysaccharide or a polyester which bears said n linker groups of formula (XIX). Typically, Q is a polyester which bears said n linker groups. The polyester may for instance be Nylon, polyethylene terephthalate (PET) or polyoxyethylene terephthalate (POET).

[0357] Alternatively Q may be a core moiety of formula (XIV) or formula (XVI): wherein n is an integer of 3 to 10, wherein A and AHCare as defined above, and wherein each A4, which is the same or different, is selected from a single bond, -Z3-arylene-*, -Z3-heteroarylene-*, - Z3-CI-2O alkylene-*, arylene, heteroarylene, C1-20 alkylene, -C(O)-*, S(O)2, -OC(O)-*, -N(R”)C(O)-*, C1-20 alkenylene, C1-20 alkynylene, -Z3-CI-2O alkenylene-* and -Z3-CI-2O alkynylene-*, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, Ci-e alkyl and aryl, and wherein * is the point of attachment of A4to L.

[0358] Alternatively, Q may be a core moiety of formula (XIV) or formula (XVI) wherein

[0359] A is an aryl or heteroaryl ring; q, m and p are the same or different and are independently selected from 0 and an integer of 1 to 20; and each A4, which is the same or different, is selected from a single bond, -Z3-arylene-*, -Z3- heteroarylene-*, -Z3-CI-2O alkylene-*, arylene, heteroarylene, C1-20 alkylene, -C(O)-*, S(O)2, -OC(O)- *, -N(R”)C(O)-*, C1-20 alkenylene, C1-20 alkynylene, -Z3-CI-2O alkenylene-* and -Z3-CI-2O alkynylene- *, wherein Z3is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, Ci-e alkyl and aryl, and wherein * is the point of attachment of A4to L.

[0360] In one embodiment, A4is C(O). Thus, Q may be the following core moiety:

[0361] In one embodiment, the crosslinker compound of formula (II) is of formula (XX), formula (XXa), or formula (XXb) wherein n, Q and XLare as defined hereinbefore and R3is C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, cyano, nitro, hydroxy, halo, carboxy, amino, Ci-w alkylamino, di(Ci-io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acyl, acyloxy, acylamido, ester, C1-10 alkoxy, aryloxy, haloalkyl, thiol, C1-10 alkylthio, arylthio, sulfonic acid, sulfonyl, sulfonamide, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl or triarylsilyl. Ts is tosyl. More typically, R3is H orNCh. Even more typically, R3is NO2. Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro. Typically, Q comprises a polymer and n is an integer equal to or greater than 50. Typically, the polymer is a polysaccharide, for instance a galactomannan, e.g. locust bean gum. Alternatively, the polymer may be a polyester, for instance nylon, polyethylene terephthalate (PET) or polyoxyethylene terephthalate (POET).

[0362] Typically, the crosslinker compound of formula (II) is of formula (XXa).

[0363] In another embodiment, the crosslinker compound of formula (II) is of formula (XXI), formula (XXIa), or formula (XXIb) wherein n, Q, R3and XLare as defined hereinbefore. Ts is tosyl. Typically, R3is H or NO2. Even more typically, R3is NO2. Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro. Typically, Q comprises a polymer and n is an integer equal to or greater than 50. Typically, the polymer is a polysaccharide, for instance a galactomannan, e.g. locust bean gum. Alternatively, the polymer may be a polyester, for instance nylon, polyethylene terephthalate (PET) or polyoxyethylene terephthalate (POET).

[0364] Typically, the crosslinker compound of formula (II) is of formula (XXIa).

[0365] In another embodiment, the crosslinker compound of formula (II) is of formula (XXII), (XXIIa) or (XXIIb) wherein n, Q and R3are as defined hereinbefore. Ts is tosyl. Typically, R3is H or NO2. In one embodiment Q comprises a polymer and n is an integer equal to or greater than 50. The polymer may for instance be a polysaccharide, for instance a galactomannan, e.g. locust bean gum. Alternatively, Q may be a polyester which bears n linker groups of formula (XIX) as defined hereinbefore . In another embodiment, Q is a core moiety as defined hereinbefore. Typically, when Q is a core moiety n is an integer of from 3 to 50, or from 3 to 10. More typically, when Q is a core moiety n is 3. Q may for instance be the following core moiety, wherein n is 3 :

[0366] In another embodiment, the crosslinker compound of formula (II) is of formula (XXIII), (XXIIIy) or (XXIIIz)

[0367] (XXIIIz) wherein r is an integer of from 1 to 4 and each r is the same or different, and n, Q and R3are as defined hereinbefore. Ts is tosyl. Typically, R3is H or NO2. In one embodiment Q comprises a polymer and n is an integer equal to or greater than 50. The polymer may for instance be a polysaccharide, for instance a galactomannan, e.g. locust bean gum. In another embodiment, Q is a core moiety as defined hereinbefore. Typically, when Q is a core moiety n is an integer of from 3 to 50. More typically, when Q is a core moiety n is an integer of from 3 to 10. More typically, when Q is a core moiety n is 3. Q may for instance be any one of the following core moieties, wherein n is 3:

[0368] In another embodiment, the crosslinker compound of formula (II) is a compound of formula (XXIV) or (XXV) wherein n is an integer equal to or greater than 50 and wherein XLis halo, hydroxyl, Ci-w alkoxy, C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, aryl, aralkyl, cyano, amino, Ci-w alkylamino, di(Ci. io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, C1-20 haloalkyl, ester, acyl, acyloxy, aryloxy, nitro, carboxy, sulfonic acid, sulfonyl, sulphonamide, thiol, C 1-10 alkylthio or arylthio. Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro.

[0369] In another embodiment, the crosslinker compound of formula (II) is a compound of formula (XXIVa) or (XXVa) wherein n is an integer equal to or greater than 50 and wherein XLis halo, hydroxyl, Ci-w alkoxy, C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, aryl, aralkyl, cyano, amino, Ci-w alkylamino, di(Ci. io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acylamido, C1-20 haloalkyl, ester, acyl, acyloxy, aryloxy, nitro, carboxy, sulfonic acid, sulfonyl, sulphonamide, thiol, C 1-10 alkylthio or arylthio. Typically, XLis halo or hydroxyl. More typically, XLis halo, for instance chloro.

[0370] In another embodiment, the crosslinker compound of formula (II) is a compound of formula (XXVII), (XXVIIa) or (XXVIII) I).

[0371] In another embodiment, the crosslinker compound of formula (II) is a compound of formula (XXVIIb) or (XXVIIc)

[0372]

[0373] (XXVIIc) wherein R1is H or tosyl.

[0374] In another embodiment, the crosslinker compound of formula (II) is a compound of formula (XXVIb) (XXVIb) wherein n is an integer equal to or greater than 50, R is as defined hereinbefore, R2is as defined hereinbefore, and Q is polystyrene or a copolymer comprising styrene monomer units (a styrene copolymer). Each sulfonylhydrazone group in the compound of formula (XXVIb) is typically bonded to a phenyl group of said polystyrene or said copolymer comprising polystyrene.

[0375] Typically, the crosslinker compound of formula (II) is of formula (XXVIc)

[0376] (XXVIc) wherein n is an integer equal to or greater than 50 and Q is polystyrene or a copolymer comprising styrene monomer units (a styrene copolymer). Each sulfonylhydrazone group in the compound of formula (XXVIc) is typically bonded to a phenyl group of said polystyrene or said copolymer comprising polystyrene. The copolymer comprising styrene monomer units may for instance be poly(styrene)-poly(ethylene / butylene)-poly(styrene) (SEBS).

[0377] The crosslinker compounds of formula (II) disclosed herein can be synthesized as described in WO 2010 / 100410 Al, and in the priority documents of WO 2010 / 100410 Al, GB 0903563.5 and GB 0914692.9.

[0378] As described in WO 2010 / 100410 Al and its priority documents, the multiple reactive intermediate precursor groups of the crosslinker compound of formula (II) can be readily converted into carbene or nitrene reactive intermediate groups, which can in turn react with and bond to a wide variety of substrates, including individual molecules and bulk materials.

[0379] Thus, the reacted crosslinker in the anion-conducting composite material of the present invention is typically obtainable by generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups in the crosslinker compound of formula (II), so that the carbene reactive intermediate groups react with the porous support material and the cationic polymer. The carbene reactive intermediate groups are highly reactive and are therefore capable of reacting with the porous support material, the cationic polymer and with the crosslinker compound itself (either intermolecularly, with another molecule of the crosslinker compound, or intramolecularly with another moiety in the same molecule of the crosslinker compound), and with any other molecule or moiety present in the composition. In this way, a cross-linked network comprising the cationic polymer and the reacted crosslinker is formed which is bonded to the porous support material.

[0380] Accordingly, the reacted crosslinker, in the anion-conducting composite material of the invention, may have the formula (XXVIV) (XXVIV) wherein

[0381] E’ is a carbon or nitrogen atom; x is 1 when E’ is carbon and x is 0 when E’ is nitrogen;

[0382] * is a point of attachment of the reacted crosslinker to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition; n is an integer equal to or greater than 3; each R, which is the same or different, is a terminal group; each L, which is the same or different, is a single bond or a linker group; and

[0383] Q is a core moiety, a polymer or a dendrimer.

[0384] The integer n may be as further defined anywhere herein for the crosslinker compound.

[0385] Each L may be as further defined anywhere herein for the crosslinker compound of formula (II). Similarly, each R may be as further defined anywhere herein for the crosslinker compound of formula (II). Similarly, Q may be as further defined anywhere herein for the crosslinker compound of formula (II).

[0386] As defined above, * is a point of attachment of the carbon or nitrogen atom, E’ to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition. The other molecule or moiety in the composition may be another molecule or moiety of the reacted crosslinker. Alternatively, the other molecule or moiety in the composition may be a further cationic compound, for instance a cationic small molecule, or a further cationic polymer (where more than one type of cationic polymer is present in the composition). Alternatively, the other molecule or moiety in the composition may be a further reacted crosslinker, where more than one type of reacted crosslinker is present in the composition.

[0387] In the reacted crosslinker of formula (XXVIV), E’ may be a nitrogen atom, in which case x is 0.

[0388] Preferably, however, E’ is a carbon atom, and x is 1. Accordingly, in one embodiment, the reacted crosslinker, in the anion-conducting composite material of the invention, has the formula (XXVIVa) wherein * is a point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition, and wherein R, L, n and Q are as defined above for the reacted crosslinker of formula (XXVIV).

[0389] As discussed above, the point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition, is depicted

[0390] Thus, in the anion -conducting composite material of the invention, the carbon atom marked “*” is bonded to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition, for instance another reacted crosslinker compound of formula (XXVIVa). As the skilled person would understand, various different modes of binding of the reacted crosslinker compound to the porous support material, the cationic polymer, or another molecule or moiety in the composition are possible via that carbon atom. For instance, the bond between the carbon atom marked “*” and an atom “Z” of the porous support material or the cationic polymer (or an atom “Z” of another molecule or moiety in the composition) may be a single covalent bond, in which case that carbon atom is also bonded to another atom or group (for example a hydrogen atom), as follows:

[0391] Z

[0392] C IH ^A

[0393] Alternatively, the bond between the carbon atom marked “*” and an atom “Z” of the porous support material or the cationic polymer (or an atom “Z” of another molecule or moiety in the composition) may be a double bond, as follows:

[0394] Alternatively, the bond between the carbon atom marked “*” and an atom “Z” of the porous support material or the cationic polymer (or an atom “Z” of another molecule or moiety in the composition) may be a dative bond (also known as a coordinate bond), in which both electrons are provided by the carbon atom, as follows:

[0395] Z f X ^A

[0396] Alternatively, the carbon atom marked “*”may be bonded to two atoms, “Z” and “Z”’, of the porous support material or the cationic polymer (or to two atoms, “Z” and “Z”’, of another molecule or moiety in the composition; or to one atom, “Z”, of the cationic polymer and to another atom, “Z”’, of another molecule or moiety in the composition) wherein the bonds between the carbon atom marked “*” and the atoms Z and Z’ are both single bonds, as follows:

[0397] The crosslinker compounds described herein, including the crosslinker compounds of formula (II) and the polymer comprising repeat units of formula (X), can thereby be used to cross link two or more substrates, compounds, molecules or moieties, which two or more substrates may be the same or different. The carbene and nitrene reactive intermediate groups are highly reactive and are therefore capable of reacting with two or more substrates, compounds, molecules or moieties to bond them together. Thus, they can react with the porous support material, the cationic polymer and with the crosslinker compound itself (either intermolecularly, with another molecule of the crosslinker compound, or intramolecularly with another moiety in the same molecule of the crosslinker compound), and with any other molecule or moiety present in the composition. In this way, a three- dimensional cross-linked network comprising the cationic polymer and the reacted crosslinker is formed which is bonded to the porous support material.

[0398] Anion-conducting composite material -further features

[0399] In the composition comprising the cationic polymer and the reacted crosslinker that is disposed on the porous support material, the cationic polymer and the reacted crosslinker may or may not be evenly distributed throughout the composition. In some embodiments, the cationic polymer and the reacted crosslinker are evenly distributed throughout said composition. Thus, the cationic polymer and reacted crosslinker may have a relatively constant concentration throughout the composition. Alternatively, the composition may comprise discrete layers, built up on the porous support material, with different amounts of the cationic polymer and reacted crosslinker in each. These may include a layer which chiefly comprises the reacted crosslinker, and a layer which chiefly comprises the cationic polymer, and optionally one or more intermediate layers in between, comprising both cationic polymer and reacted crosslinker. Alternatively, the composition may comprise a concentration gradient wherein the concentrations of the cationic polymer and the reacted crosslinker vary throughout the thickness of the composition. For instance, the concentration of the reacted crosslinker may be highest where the composition meets the surface of the porous support material and then progressively decrease as one moves away from that surface, and the concentration of the cationic polymer may be lowest where the composition meets the surface of the porous support material and then progressively increase moving away from the support material.

[0400] The distribution of the cationic polymer and the reacted crosslinker components in the composition may be influenced by how the composition is produced. For instance, if the composition is produced by (a) disposing a precursor composition on the porous support material, wherein the precursor composition comprises a solution, or a homogeneous blend, of the cationic polymer and the crosslinker compound, and then (b) curing the disposed composition to generate carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups of the crosslinker, this will typically result in a composition disposed on the porous support material that comprises a homogeneous distribution of the cationic polymer and the reacted crosslinker components. That is to say, the cationic polymer components may be distributed evenly, i.e. at a relatively constant concentration, throughout the composition disposed on the porous support material, and similarly the reacted crosslinker components may be distributed evenly, i.e. at a relatively constant concentration, throughout said composition.

[0401] However, if, for instance, the composition disposed on the porous support material is produced by: (a) disposing a crosslinker precursor composition on the porous support material, which comprises the crosslinker compound but none of, or a relatively low amount of, the cationic polymer, and subsequently disposing a polymer composition on the porous support material, which comprises the cationic polymer but none of, or a relatively low amount of, the crosslinker compound; and then (b) curing these disposed compositions to generate carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups of the crosslinker, the resulting composition may have two or more discrete layers with different quantities of the cationic polymer and reacted crosslinker components.

[0402] Indeed, if the composition on the porous support material is produced in this way, the crosslinker precursor composition may lead to the formation a first layer in the resulting cured composition, which is typically disposed directly on the surface of the porous support material, and the polymer composition may lead to the formation of a second layer in the resulting cured composition, which is disposed on the first layer. Generally, the first layer will have a relatively high concentration of the reacted crosslinker compared to the second layer and the second layer will have a relatively high concentration of the cationic polymer compared to the first layer. These first and second layers may intermingle at their interface, to a certain extent, to form an intermediate layer or region, in between the first and second layers. An intermediate layer or region, if present, typically has intermediate concentrations of both the reacted crosslinker and the cationic polymer.

[0403] Optionally, in between disposing the crosslinker precursor composition on the porous support material (which may lead to the aforementioned first layer) and disposing the polymer composition on the porous support material (which may lead to the aforementioned second layer), one or more intermediate precursor compositions can be disposed on the porous support material, with the intention of forming one or more intermediate layers in the resulting “cured” composition (the one or more intermediate layers being in between the aforementioned first and second layers).

[0404] In this way, the composition comprising the cationic polymer and the reacted crosslinker, that is disposed on the porous support material, may comprise: a first layer, which is disposed on the surface of the porous support material, and a second layer disposed on the first layer, wherein the first layer comprises the reacted crosslinker and the second layer comprises the cationic polymer. Optionally, the composition comprising the cationic polymer and the reacted crosslinker may further comprise one or more intermediate layers, disposed between the first layer and the second layer. Usually each of the one or more intermediate layers comprises the reacted crosslinker and the cationic polymer.

[0405] Typically, the first layer comprises a higher concentration of the reacted crosslinker than the second layer, and the second layer comprises a higher concentration of the cationic polymer than the first layer. Often, the first layer comprises little or no cationic polymer and the second layer comprises little or no reacted crosslinker. For instance, the first layer may not comprise said cationic polymer, and the second layer may not comprise said reacted crosslinker (in which case the layer of the reacted crosslinker may bind the layer of the cationic polymer to the surface of the porous support material). Thus, typically, the first layer does not comprise the cationic polymer, or the concentration of the cationic polymer in the first layer is lower than the concentration of the cationic polymer in the second layer; and the second layer does not comprise the reacted crosslinker, or the concentration of the reacted crosslinker in the second layer is lower than the concentration of the reacted crosslinker in the first layer.

[0406] Often, in each of the one or more intermediate layers, the concentration of the cationic polymer is in between the concentration of the cationic polymer in the first layer and the concentration of the cationic polymer in the second layer. Similarly, in each of the one or more intermediate layers, the concentration of the reacted crosslinker is typically in between the concentration of the reacted crosslinker in the first layer and the concentration of the reacted crosslinker in the second layer.

[0407] Thus, typically, in each of the one or more intermediate layers, the concentration of the cationic polymer is less than the concentration of the cationic polymer in the second layer and greater than the concentration of the cationic polymer in the first layer, and the concentration of the reacted crosslinker is less than the concentration of the reacted crosslinker in the first layer and greater than the concentration of the reacted crosslinker in the second layer.

[0408] The first layer, second layer, and any intermediate layers present, may intermingle at an interface between two layers to form a region therebetween, in which the concentrations of the reacted crosslinker and the cationic polymer components are intermediate between their concentrations in the two layers either side. In this way, by controlling the relative concentrations of the reacted crosslinker and the cationic polymer components in the various layers, a relatively smooth concentration gradient may be formed throughout the composition comprising the cationic polymer and the reacted crosslinker that is disposed on the porous support material.

[0409] Thus, in some embodiments, the composition disposed on the porous support material may comprise a concentration gradient. Thus, often, the concentrations of the cationic polymer and the reacted crosslinker components vary throughout the thickness of the disposed composition. For instance, the concentration of the reacted crosslinker in the composition may decrease from a relatively high concentration where the composition meets the surface of the porous support material, to a relatively low concentration at regions of the composition that are farthest away from the surface of the porous support material. Similarly, the concentration of the cationic polymer in the composition may increase from a relatively low concentration where the coating meets the surface of the porous support material to a relatively high concentration at regions of the coating that are farthest away from the surface of the porous support material.

[0410] Accordingly, in some embodiments, the concentration of the reacted crosslinker in the composition disposed on the porous support material decreases from a first crosslinker concentration at a region of the composition that is proximal to (and typically in contact with) a surface of the porous support material, to a second crosslinker concentration at a region of the composition that is distal to said surface of the porous support material, wherein the first crosslinker concentration is greater than the second crosslinker concentration.

[0411] Furthermore, typically, the concentration of the cationic polymer in the composition disposed on the porous support material decreases from a first polymer concentration at a region of the composition that is distal to a surface of the porous support material, to a second polymer concentration at a region of the composition that is proximal to (and typically in contact with) said surface of the porous support material, wherein the first polymer concentration is greater than the second crosslinker concentration.

[0412] The cationic polymer in these embodiments may be as further defined anywhere herein. Often, however, it is a cationic polymer which comprises a repeat unit which comprises a covalently-bonded cationic group, wherein said cationic group comprises a quaternary nitrogen atom. Often said cationic group is selected from quaternary ammonium groups, quaternary imidazolium groups, quaternary pyridinium groups and quaternary pyrrolidinium groups. Often, in these embodiments the cationic polymer is a quaternary ammonium polymer. For instance, in these embodiments the cationic polymer is often polydiallyldimethylammonium chloride (pDADMAC). An outer layer comprising cationic groups having a quaternary nitrogen atom, such as an outer layer comprising quaternary ammonium groups, is advantageous for life sciences applications, for instance in order to enable binding of proteins to the composition on the porous support material.

[0413] The abovementioned first layer, second layer, and any intermediate layers present in the composition, may further comprise additional components as defined herein, in particular each may further comprise: one or more further cationic compounds and / or one or more further reacted crosslinkers. For the one or more further cationic compounds, each further cationic compound may independently be a further cationic polymer or a cationic small molecule as described herein. For the one or more further reacted crosslinkers, one or more of the further reacted crosslinkers may be as defined herein for the reacted crosslinker and / or may be obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein.

[0414] For instance, it may be the case that: - the abovementioned second layer further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or

[0415] - the abovementioned first layer further comprises one or more further reacted crosslinkers, optionally wherein one or more of the further reacted crosslinkers is as defined herein for the reacted crosslinker and / or is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein; and / or

[0416] - any of the abovementioned one or more intermediate layers further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or

[0417] - any of the abovementioned one or more intermediate layers further comprises one or more further reacted crosslinkers, optionally wherein one or more of the further reacted crosslinkers is as defined herein for the reacted crosslinker and / or is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein.

[0418] The composition comprising the cationic polymer and the reacted crosslinker is described as being disposed on the porous support material. As described above, the composition comprising the cationic polymer and the reacted crosslinker is generally bonded to the porous support material. In particular, it is bonded to a surface of the porous support material. Thus, the composition comprising the cationic polymer and the reacted crosslinker may be described as being disposed on a surface of the porous support material. It may also be described as coating a surface of the porous support material, or as being bonded to a surface of the porous support material. Note that being disposed on, or bonded to, or coating, a surface of the porous support material typically includes being disposed on, bonded to, or coating, an internal surface of the porous support material as well as the support material’s external surface.

[0419] Thus, in the anion-conducting composite material of the invention, the composition comprising the cationic polymer and the reacted crosslinker may be disposed on an internal surface of the porous support material and on an external surface of the porous support material. In particular, the composition may be disposed on walls of pores within the porous support material. It may also be disposed on an external surface of the porous support material.

[0420] The composition comprising the cationic polymer and the reacted crosslinker may coat an internal surface of the porous support material and an external surface of the porous support material. In particular, the composition may coat walls of pores within the porous support material. It may also coat an external surface of the porous support material.

[0421] The composition comprising the cationic polymer and the reacted crosslinker may be bonded to an internal surface of the porous support material and to an external surface of the porous support material. In particular, the composition may be bonded to walls of pores within the porous support material. It may also be bonded to an external surface of the porous support material. In some preferred embodiments, the composition comprising the cationic polymer and the reacted crosslinker is disposed on the entire surface of the porous support material. The entire surface, in this context may include the entire external surface of the porous support material and the entire internal surface of the porous support material. Thus the composition may be disposed on the walls of all the pores (meaning all the open pores) within the porous support material as well as on the entire external surface of the porous support material.

[0422] The term “open pore” herein, refers to a pore of the porous support material that is accessible to the external environment (before the composition comprising the cationic polymer and the reacted crosslinker is been disposed on the porous support material) and which may therefore be accessed by a fluid (for instance a solvent or liquid composition) to which the porous support material is exposed. In contrast, a closed pore is one which is isolated within the porous support material and which cannot therefore be accessed by a fluid to which the porous support material is exposed. Unless otherwise stated, references herein to a pore of the porous support material are references to an open pore of the porous support material, and references to “all the pores” of, or within, the porous support material are references to all of the open pores of, or within, the porous support material.

[0423] Thus, the composition comprising the cationic polymer and the reacted crosslinker may coat the entire surface of the porous support material. The composition may for instance coat the walls of all the pores within the porous support material as well as coat the entire external surface of the porous support material.

[0424] Similarly, the composition comprising the cationic polymer and the reacted crosslinker may be bonded to entire surface of the porous support material. Thus, the composition may be bonded to the walls of all the pores within the porous support material as well as to the entire external surface of the porous support material.

[0425] The composition comprising the cationic polymer and the reacted crosslinker may be disposed in pores of the porous support material. The composition may or may not be disposed in all of the pores of the porous support material. Often, however, the composition is disposed in all the pores of the porous support material.

[0426] In some preferred embodiments, the composition comprising the cationic polymer and the reacted crosslinker fills pores of the porous support material.

[0427] The composition may for instance fill the pores of the porous support material - i.e. all of the pores of the support material. The anion-conducting composite material of the invention may therefore be non-porous, due to all the pores of the porous support material having been filled-in. By filling a pore, herein, is meant completely filling a pore, unless otherwise stated.

[0428] Thus, often, the anion-conducting composite material of the invention is non-porous.

[0429] Alternatively, the anion-conducting composite material of the invention may be porous. This may be because not all of the pores of the porous support material are filled by the composition comprising the cationic polymer and the reacted crosslinker, and therefore some pores (gaps) remain in the composite material, and / or because the composition comprising the cationic polymer and the reacted crosslinker does not completely fill some or all of the pores of the porous support material but only partially fills them such that porosity remains in the composite material.

[0430] Thus, in some embodiments, the composition comprising the cationic polymer and the reacted crosslinker partially fills pores of the porous support material. Additionally, or alternatively, the composition comprising the cationic polymer and the reacted crosslinker may fill a first plurality of pores within the porous support material and may not fill a second plurality of pores within the porous support material.

[0431] In some embodiments, therefore, the anion conducting composite material of the invention is porous.

[0432] Thus, the anion conducting composite material may be non-porous, i.e. it may have a porosity of 0 %, or it may be porous, i.e. it may have a porosity of greater than 0%. The porosity of the anion conducting composite material may for instance be from 0 % to 30 %. For example, the porosity of the anion conducting composite material may be from 0 % to 20 %, for instance from 0 % to 15 %, or from 0 % to 10 %, or for instance from 0 % to 8 %, or from 0 % to 4 %.

[0433] When the anion conducting composite material of the invention is porous, it may for instance have a porosity of from greater than 0 % to 30 %, for instance from greater than 0 % to 20 %. The anion conducting composite material may, for instance, have a porosity of from greater than 0 % to 15 %, for instance from greater than 0 % to 15 %, or from greater than 0 % to 10 %, for instance from greater than 0 % to 8 %, or from greater than 0 % to 4 %. The porosity may for instance be from 0.1 % to 20 %, for instance from 1 % to 15 %, or from 1 % to 10 %, for instance from 1 % to 8 %, or from 1 % to 4 %.

[0434] When the anion -conducting composite material is porous, it may have a pore size of from 50 nm to 20 pm, for instance from 100 nm to 15 pm, or from 500 nm to 15 pm, for instance from 1 pm to 10 pm, or from 1 pm to 5 pm.

[0435] As discussed hereinbefore, the porous support material may be a porous membrane. Thus, the anion-conducting composite material of the invention may be a membrane, which is referred to herein as an anion-conducting membrane.

[0436] When the anion-conducting composite material of the invention is an anion-conducting membrane, the anion-conducting membrane may be non-porous or porous, for the reasons explained above. A non-porous anion-conducting membrane may be desired for some end uses, whereas a certain level of porosity in the anion-conducting membrane may be preferred for other end uses. The amount of the composition comprising the cationic polymer and the crosslinker that is disposed on the porous support material may be varied during the preparation of the anion-conducting membrane, in order to tailor the porosity of the anion-conducting membrane as desired for the end use.

[0437] Often therefore, the anion-conducting composite material of the invention is a non-porous anion-conducting membrane. In other embodiments, however, the anion-conducting composite material of the invention is a porous membrane.

[0438] The anion-conducting membrane of the invention may have a thickness of from 1 pm to 500 pm. a thickness of from 1 pm to 500 pm. Often, for instance the anion-conducting membrane of the invention has a thickness of from 5 pm to 500 pm, for instance a thickness of from 10 pm to 500 pm.

[0439] The anion-conducting membrane of the invention may for instance have a thickness of from 5 pm to 300 pm, for instance from 5 pm to 200 pm, or from 10 pm to 200 pm. Often, for instance the anion-conducting membrane of the invention has a thickness of from 10 pm to 150 pm, for instance a thickness of from 20 pm to 150 pm, or from 25 pm to 125 pm. Such thicknesses are common for anion exchange membranes.

[0440] The anion-conducting membrane of the invention may be an anion exchange membrane.

[0441] The invention also therefore provides the use of the anion-conducting membrane of the invention as an anion exchange membrane.

[0442] Process for producing the anion-conducting composite material

[0443] The invention provides a process for producing an anion-conducting composite material, which process comprises:

[0444] (a) contacting a porous support material with a cationic polymer and a crosslinker compound, wherein the crosslinker compound comprises n reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B), and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group; and

[0445] (b) generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0446] In the process of the invention for producing an anion-conducting composite material, the porous support material may optionally be as further defined anywhere herein. In addition, in the process of the invention, the cationic polymer may be as further defined anywhere herein. In addition, in the process of the invention, the crosslinker compound may be as further defined anywhere herein. In addition, in the process of the invention for producing an anion-conducting composite material, the anion-conducting composite material may be as further defined anywhere herein.

[0447] In the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise disposing the cationic polymer and the crosslinker compound on the porous support material, for instance disposing the cationic polymer and the crosslinker compound on a surface of the porous support material. Contacting the porous support material with a cationic polymer and a crosslinker compound may comprise coating the cationic polymer and the crosslinker compound on the porous support material, for instance coating the cationic polymer and the crosslinker compound on a surface of the porous support material. Note that disposing, or coating, the cationic polymer and the crosslinker compound on a surface of the porous support material typically includes disposing, or coating, the cationic polymer and the crosslinker compound on an internal surface of the porous support material as well as the support material’s external surface.

[0448] Thus, in the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise disposing (or coating) the cationic polymer and the crosslinker compound on an internal surface of the porous support material and on an external surface of the porous support material. In particular, it may comprise disposing (or coating) the cationic polymer and the crosslinker compound on walls of pores within the porous support material. It may also comprise disposing (or coating) the cationic polymer and the crosslinker compound on an external surface of the porous support material. The cationic polymer and the crosslinker compound may for instance be disposed on the entire surface of the porous support material. The entire surface, in this context may include the entire external surface of the porous support material and the entire internal surface of the porous support material. Thus, the cationic polymer and the crosslinker compound may be disposed on the walls of all the pores (meaning all the open pores) within the porous support material as well as on the entire external surface of the porous support material.

[0449] In the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise disposing (or coating) the cationic polymer and the crosslinker compound in pores of the porous support material. The cationic polymer and the crosslinker compound may or may not be disposed in all of the pores of the porous support material. Often, however, the cationic polymer and the crosslinker compound are disposed in all the pores of the porous support material.

[0450] In some preferred embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises filling the pores of the porous support material with the cationic polymer and the crosslinker compound (and optionally with any further cationic compounds or crosslinker compounds that may also be present). In other embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises partially filling pores of the porous support material with the cationic polymer and the crosslinker compound. Additionally, or alternatively, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise filling a first plurality of pores within the porous support material with the cationic polymer and the crosslinker compound, and not filling a second plurality of pores within the porous support material with the cationic polymer and the crosslinker compound.

[0451] In this way, the porosity of the final anion-conducting composite material may be controlled, and porous or non-porous anion-conducting composite materials may be prepared.

[0452] In the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise contacting the porous support material first with the cationic polymer and then with the crosslinker compound, or contacting the porous support material first with the crosslinker compound and then with the cationic polymer, or it may comprise contacting the porous support material with both the cationic polymer and the crosslinker compound simultaneously. The first option - i.e. contacting the porous support material first with the cationic polymer and then with the crosslinker compound - may be achieved by disposing the cationic polymer on the porous support material and subsequently disposing the crosslinker compound on the cationic polymer. Thus, a composition comprising the cationic polymer (for instance a polymer composition as described herein, which may further comprise a solvent) may be disposed on the porous support material first, followed by a composition comprising the crosslinker compound (for instance a crosslinker precursor composition as described herein, which may further comprise a solvent). Similarly, the second option - i.e. contacting the porous support material first with the crosslinker compound and then with the cationic polymer - may be achieved by disposing the crosslinker compound on the porous support material, and subsequently disposing the cationic polymer on the crosslinker compound. Thus, a composition comprising the crosslinker compound (for instance a crosslinker precursor composition as described herein, which may further comprise a solvent) may be disposed on the porous support material first, followed by a composition comprising the cationic polymer (for instance a polymer composition as described herein, which may further comprise a solvent). The third option - i.e. contacting the porous support material with both the cationic polymer and the crosslinker compound simultaneously - may, for instance, be achieved by contacting the porous support material with a mixture comprising the cationic polymer and the crosslinker compound (for instance a precursor composition comprising the cationic polymer and the crosslinker compound as described herein), or by contacting the porous support material with two different precursor compositions simultaneously, one precursor composition comprising the cationic polymer (for instance a polymer composition as described herein, which may further comprise a solvent) and the other precursor composition comprising the crosslinker compound (for instance a crosslinker precursor composition as described herein, which may further comprise a solvent).

[0453] The process of the invention may further comprise contacting the porous support material with one or more further cationic compounds and / or with a further crosslinker compound. It may for instance further comprise disposing (or coating) one or more further cationic compounds and / or a further crosslinker compound on the porous support material, which coating or disposing may optionally be as further defined above for the cationic polymer and the crosslinker compound.

[0454] Typically, in the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing a precursor composition on the porous support material, wherein the precursor composition comprises the cationic polymer and the crosslinker compound.

[0455] Usually, the precursor composition is in the form of a liquid. Typically, the precursor composition further comprises a solvent. A wide range of solvents are suitable, and any suitable solvent may be employed. The solvent is often for instance a polar solvent, for instance a polar organic solvent. The solvent may be a polar protic solvent. The solvent is often an alcohol. The solvent may for instance be methanol or ethanol. The solvent may alternatively be a polar aprotic solvent, for instance acetone. When the precursor composition further comprises a solvent, the total solid content of the precursor composition is typically from 1 % by weight to 60 % by weight, for instance from 5 % by weight to 60 % by weight. It may for instance be from 10 % by weight to 60 % by weight, more typically from 20 % by weight to 50 % by weight.

[0456] The ratio by weight of the cationic polymer to the crosslinker compound employed in the process of the invention is typically from 5: 1 to 1:4. It may for instance be from 3: 1 to 1:2, or from 2: 1 to 1: 1. The weight ratio of the of the cationic polymer to the crosslinker compound employed may for instance be about 1.5: 1, i.e. 3:2. Thus, the ratio by weight of the cationic polymer to the crosslinker compound in the precursor composition is typically from 5: 1 to 1:4. It may for instance be from 3 : 1 to 1 :2, or from 2: 1 to 1: 1. The weight ratio of the of the cationic polymer to the crosslinker compound employed in the precursor composition may for instance be about 1.5: 1, i.e. 3:2.

[0457] The process of the invention may further comprise contacting the porous support material with one or more further cationic compounds.

[0458] Typically, the or each further cationic compound is independently a further cationic polymer or a cationic small molecule.

[0459] The or each further cationic polymer may be as further defined anywhere herein for the cationic polymer (thus, two or more such cationic polymers may be used).

[0460] The or each cationic small molecule typically comprises a small molecule cation. The small molecule cation may be a quaternary ammonium cation, a quaternary phosphonium cation, a tertiary sulfonium cation, or a heterocyclic cation (for instance a C3-20 heterocyclic cation or a heteroaryl cation) which contains a quaternary nitrogen ring atom. The heterocyclic cation which contains a quaternary nitrogen ring atom may for instance be a quaternary imidazolium cation, a quaternary pyridinium cation, or a quaternary pyrrolidinium cation. An example of a small molecule cation which is a quaternary ammonium cation is benzyltriethylammonium.

[0461] The or each cationic small molecule typically further comprises a counter anion. The counter anion of the cationic small molecule is often a halide. Alternatively, the counter anion may be hydroxide or carbonate. Thus, the or each cationic small molecule may, for instance, be selected from quaternary ammonium salts, salts of heterocyclic compounds (for instance C3-20 heterocyclic compounds or heteroaryl compounds) which contain a quaternary nitrogen ring atom, quaternary phosphonium salts, and tertiary sulfonium salts. The or each cationic small molecule may for instance be selected from quaternary ammonium salts, quaternary imidazolium salts, quaternary pyridinium salts, quaternary pyrrolidinium salts, quaternary phosphonium salts and tertiary sulfonium salts, or may be selected from quaternary ammonium salts, quaternary imidazolium salts, quaternary pyridinium salts, and quaternary pyrrolidinium salts. Often, benzyltriethylammonium chloride is employed as the cationic small molecule.

[0462] The one or more further cationic compounds may be included in the above-defined precursor composition which comprises the cationic polymer and the crosslinker compound. Alternatively, the one or more further cationic compounds may be disposed on the porous support material separately, either before, during or after contacting the porous support material with the cationic polymer and the crosslinker compound.

[0463] Often, however, the above-defined precursor composition which comprises the cationic polymer and the crosslinker compound, further comprises one or more further cationic compounds. Thus, the precursor composition disposed on the porous support material may further comprise a further cationic polymer or a cationic small molecule, which may be as further defined above. Often, the precursor composition further comprises a cationic small molecule, which may be as further defined above.

[0464] The ratio by weight of the cationic polymer to the cationic small molecule employed in the process of the invention may, for instance, be from 2: 1 to 10: 1, for instance from 3: 1 to 7: 1. It may for instance be about 5: 1. Thus, when the precursor composition further comprises a cationic small molecule, the ratio by weight of the cationic polymer to the cationic small molecule employed in the precursor composition may, for instance, be from 2: 1 to 10: 1, for instance from 3: 1 to 7: 1. It may for instance be about 5: 1.

[0465] The process of the invention may further comprise contacting the porous support material with a further crosslinker compound. It may further comprise contacting the porous support material with a plurality of further crosslinker compounds. The or each further crosslinker compound may be as further defined anywhere herein for the crosslinker compound. The or each further crosslinker compound may for instance be a polymer comprising repeat units of formula (X), or a crosslinker compound of formula (II), as defined herein. Thus, two or more such crosslinker compounds may be used in the process of the invention (namely the crosslinker compound discussed in detail hereinbefore, and the one or more further crosslinker compounds).

[0466] The one or more further crosslinker compounds may be included in the above-defined precursor composition which comprises the cationic polymer and the crosslinker compound. Alternatively, the one or more further crosslinker compounds may be disposed on the porous support material separately, either before, during or after contacting the porous support material with the cationic polymer and the crosslinker compound.

[0467] Often, however, the above-defined precursor composition which comprises the cationic polymer and the crosslinker compound, further comprises a further crosslinker compound.

[0468] The further crosslinker compound is different from the crosslinker compound, and may be as further defined anywhere herein for the crosslinker compound. It may for instance be a polymer comprising repeat units of formula (X), or a crosslinker compound of formula (II).

[0469] The ratio by weight of the crosslinker compound to the further crosslinker compound employed in the process of the invention may, for instance, be from 6: 1 to 1:6, for instance from 3: 1 to 1 :3. It may for instance be about 1: 1. Thus, when the precursor composition further comprises a further crosslinker compound, the ratio by weight of the crosslinker compound to the further crosslinker compound employed in the precursor composition may, for instance, be from 6: 1 to 1:6, for instance from 3 : 1 to 1 : 3. It may for instance be about 1: 1.

[0470] Thus, in the process of the invention, the precursor composition may further comprise:

[0471] - one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer (which may be as further defined herein for the cationic polymer) or a cationic small molecule (which may be as further defined anywhere herein); and / or

[0472] - one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein, for instance a (further) polymer comprising repeat units of formula (X), or a (further) crosslinker compound of formula (II).

[0473] The precursor composition may, for instance, further comprise one or more further cationic compounds and one or more further crosslinker compounds.

[0474] Thus, the precursor composition may, for instance, comprise said cationic polymer, said crosslinker compound, a solvent, one or more further cationic compounds (for instance a cationic small molecule or a further cationic polymer), and one or more further crosslinker compounds. Each of these components may be as further defined anywhere herein. The process may comprise disposing such a precursor composition on the porous support material.

[0475] As discussed above the precursor composition typically further comprises a solvent. In such cases, the process of the invention typically comprises a solvent removal step.

[0476] Thus, typically in the process of the invention, the step of (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing the precursor composition on the porous support material and removing the solvent.

[0477] The disposing of the precursor composition on the porous support material may comprise dipping the support material in the precursor composition, drop-coating the support material with the precursor composition, spray -coating the support material with the precursor composition, or spincoating the support material with the precursor composition. The solvent may be removed using any appropriate means, for instance by using heat and / or reduced pressure, or by allowing the solvent to evaporate over time. Often, the solvent is removed by heating the precursor composition on the support material. This may be referred to as a drying step. Said heating is typically at a temperature of less than 100 °C, for instance from 40 °C to 80 °C, or from 50 °C to 70 °C, and is carried out for about 5 to 20 minutes, for instance about 10 minutes.

[0478] The steps of disposing a precursor composition as defined above on the porous support material and removing the solvent may be carried out more than once (i.e. they may be repeated as necessary) to ensure complete coating of the porous support material, and / or to ensure that the desired thickness of coating is achieved, and / or to ensure that all the pores of the porous support material contain the precursor composition, and / or to ensure that the precursor composition fills all of the pores of the porous support material. In this way, the properties of the anion-conducting composite material (for instance whether or not the composite material is porous, and, if it is porous, the pore size, and for instance the thickness of the resin applied) may be tailored to suit the end use.

[0479] Where the step of disposing a precursor composition on the porous support and removing the solvent are repeated, as described above, not each precursor composition need be the same. Rather, a first precursor composition as defined above and a second precursor composition as defined above may have different concentrations of a cationic polymer and a crosslinker compound. Additionally, or alternatively, a different cationic polymer and / or crosslinker compound may be employed in the first and second precursor compositions. Additionally, or alternatively, one of the first and second precursor compositions may comprise a further cationic compound, or a further crosslinker compound, that is absent from the other precursor composition. Often, however, the first and second precursor compositions will contain the same components at different concentrations.

[0480] Thus, for instance, the process may comprise disposing a first precursor composition on the porous support material, wherein the first precursor composition comprises a cationic polymer as defined herein and a crosslinker compound as defined herein and a solvent, and removing the solvent, and disposing a second precursor composition on the porous support material, wherein the second precursor composition comprises a cationic polymer as defined herein and a crosslinker compound as defined herein and a solvent, and removing the solvent.

[0481] Often, the solids content by weight of the second precursor composition is greater than that of the first precursor composition. For instance, the total solids content of the first precursor composition may be from 20 % to 30 % by weight, for instance about 25 % by weight, and the total solids content of the second precursor composition may be from 30 % to 40 % by weight, for instance about 35 % by weight.

[0482] Additionally, or alternatively, the cationic polymer of the first precursor composition may be different from that of the second precursor composition, and / or the crosslinker compound of the first precursor composition may be different from that of the second precursor composition. Additionally, or alternatively, one of the first and second precursor compositions may comprise a further cationic compound as defined herein (for instance a cationic small molecule, or a cationic polymer) or a further crosslinker compound, that is absent from the other one of the first and second precursor compositions.

[0483] Typically, in the process of the invention, disposing the precursor composition on the porous support material comprises coating the porous support material with the precursor composition. Often, in the process of the invention, disposing the precursor composition on the porous support material comprises coating the entire surface of the porous support material with the precursor composition. This typically includes coating the insides of the pores of the porous support material. Indeed, the entire surface, in this context may include the entire external surface of the porous support material and the entire internal surface of the porous support material. Thus, the precursor composition may be disposed on the walls of all the pores (meaning all the open pores) within the porous support material as well as on the entire external surface of the porous support material.

[0484] In the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise disposing (or coating) the precursor composition in pores of the porous support material. The precursor composition may or may not be disposed in all of the pores of the porous support material. Often, however, the precursor composition is disposed in all the pores of the porous support material.

[0485] In some preferred embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises filling the pores of the porous support material with the precursor composition. Disposing the precursor composition on the porous support material may for instance comprise filling the pores of the porous support material with the precursor composition. In other embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises partially filling pores of the porous support material with the precursor composition. Additionally, or alternatively, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise filling a first plurality of pores within the porous support material with the precursor composition, and not filling a second plurality of pores within the porous support material with the precursor composition. In this way, the porosity of the final anion-conducting composite material may be controlled, and porous or non-porous anion- conducting composite materials may be prepared.

[0486] Alternatively, in the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise: disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound, and disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer. Usually, the crosslinker precursor composition does not comprise said cationic polymer, and the polymer composition does not comprise said crosslinker compound. However, other embodiments are envisaged in which the crosslinker precursor composition comprises a small amount of the cationic polymer relative to the amount of the cationic polymer in the polymer composition and / or the polymer composition comprises a small amount of the crosslinker compound relative to the amount of the crosslinker compound in the crosslinker precursor composition.

[0487] The crosslinker precursor composition and the polymer composition may be disposed on the porous support material at the same time, or at different times. They may for instance be disposed one after the other, in either order. Often, the crosslinker precursor composition is disposed first, followed by the polymer composition. Thus, the crosslinker composition may be disposed on the porous support material, and subsequently the polymer composition may be disposed on the porous support material (i.e. on the porous support material that has already been treated with the crosslinker composition). The concentration of the crosslinker component may then be higher closer to the surface of the support material.

[0488] Thus, often, in the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound, and subsequently disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer.

[0489] Typically, the crosslinker precursor composition does not comprise the cationic polymer, or the concentration of the cationic polymer in the crosslinker precursor composition is less than the concentration of the cationic polymer in the polymer composition. Furthermore, the polymer composition typically does not comprise the crosslinker compound, or the concentration of the crosslinker compound in the polymer composition is less than the concentration of the crosslinker compound in the crosslinker precursor composition. For instance, often, the crosslinker precursor composition does not comprise the cationic polymer and the polymer composition does not comprise the crosslinker compound.

[0490] Contacting the porous support material with a cationic polymer and a crosslinker compound may optionally further comprise, after disposing the crosslinker precursor composition but before disposing the polymer composition: disposing one or more intermediate precursor compositions on the porous support material. Typically, each of the intermediate precursor compositions comprises said crosslinker compound and said cationic polymer. Typically, in each of the intermediate compositions, the concentration of the cationic polymer is greater than that in the crosslinker precursor composition and less than that in the polymer composition, and the concentration of the crosslinker compound is greater than that in the polymer composition and less than that in the crosslinker precursor composition.

[0491] The cationic polymer in these embodiments may be as further defined anywhere herein. Often, however, it is a cationic polymer which comprises a repeat unit which comprises a covalently-bonded cationic group, wherein said cationic group comprises a quaternary nitrogen atom. Often said cationic group is selected from quaternary ammonium groups, quaternary imidazolium groups, quaternary pyridinium groups and quaternary pyrrolidinium groups. Often, in these embodiments the cationic polymer is a quaternary ammonium polymer. For instance, in these embodiments the cationic polymer is often polydiallyldimethylammonium chloride (pDADMAC). An outer layer comprising cationic groups having a quaternary nitrogen atom, such as an outer layer comprising quaternary ammonium groups, is advantageous for life sciences applications, for instance in order to enable the binding of proteins to the composition on the porous support material.

[0492] Usually, the crosslinker precursor composition is in the form of a liquid. Typically, the crosslinker precursor composition further comprises a solvent. A wide range of solvents are suitable, and any suitable solvent may be employed. The solvent is often for instance a polar organic solvent. The solvent may be a polar aprotic solvent, for instance acetone. Alternatively, the solvent may be a polar protic solvent, for instance an alcohol, such as methanol or ethanol. When the crosslinker precursor composition further comprises a solvent, the total solids content of the crosslinker precursor composition is typically from 1 % by weight to 60 % by weight, for instance from 5 % by weight to 60 % by weight, or more typically from 10 % by weight to 60 % by weight. It may be from 20 % by weight to 50 % by weight. As mentioned above, usually the crosslinker precursor composition does not comprise said cationic polymer. However, other embodiments are envisaged in which the crosslinker precursor composition comprises a small amount of the cationic polymer relative to the amount of the cationic polymer in the polymer composition.

[0493] Similarly, the polymer composition is typically in the form of a liquid. Typically, the polymer composition further comprises a solvent. A wide range of solvents are suitable, and any suitable solvent may be employed. The solvent is often for instance a polar solvent, which may or may not be an organic solvent. The solvent may for instance be a polar protic solvent, for instance water, or an alcohol, such as methanol or ethanol. The solvent may alternatively be a polar aprotic solvent, for instance acetone. Often, water (usually deionised water) is employed as the solvent for the polymer composition. When the polymer composition further comprises a solvent, the total solid content of the polymer composition is typically from 1 % by weight to 60 % by weight, for instance from 5 % by weight to 60 % by weight, or more typically from 10 % by weight to 60 % by weight, or it may be from 20 % by weight to 50 % by weight. As mentioned above, usually the polymer composition does not comprise said crosslinker compound. However, other embodiments are envisaged in which the polymer composition comprises a small amount of the crosslinker compound relative to the amount of the crosslinker compound in the crosslinker precursor composition.

[0494] Similarly, each of the one or more intermediate precursor compositions is typically in the form of a liquid. Typically, each of the intermediate precursor compositions further comprises a solvent, which may be as further defined above for the polymer composition or the crosslinker precursor composition. The ratio by weight of the cationic polymer to the crosslinker compound employed in the process of the invention is typically from 5: 1 to 1:4. It may for instance be from 3: 1 to 1:2, or from 2: 1 to 1: 1. The weight ratio of the of the cationic polymer to the crosslinker compound employed may for instance be about 1.5: 1, i.e. 3:2. Thus, the ratio by weight of the cationic polymer to the crosslinker compound in the precursor composition is typically from 5: 1 to 1:4. It may for instance be from 3 : 1 to 1 :2, or from 2: 1 to 1: 1. The weight ratio of the of the cationic polymer to the crosslinker compound employed in the precursor composition may for instance be about 1.5: 1, i.e. 3:2.

[0495] As discussed above, often both the crosslinker precursor composition and the polymer composition each further comprise a solvent. Thus, the process of the invention typically comprises a solvent removal step (e.g. a drying step) in which some or all of the relevant solvent is removed to render the disposed composition “dry” (i.e. relatively solvent-free). Typically, when the crosslinker precursor composition and the polymer composition are disposed on the porous support material at different times, such a solvent removal step is performed between disposing the two compositions, to dry the already-disposed composition before the next one is disposed thereon. Thus, often, when the crosslinker precursor composition is disposed first, followed by the polymer composition, a solvent removal step is performed in between these steps, in order to remove some or all of the solvent from the crosslinker precursor composition after it has been disposed on the porous support material, so that the disposed crosslinker precursor composition is relatively solvent-free before the polymer composition is disposed thereon. Similarly, a solvent removal step is typically performed after disposing each of the one or more intermediate precursor compositions on the porous support material.

[0496] For instance, often, in the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound comprises: (i) disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound and a solvent; (ii) removing said solvent; and (iii) disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer and a solvent.

[0497] If one or more intermediate precursor compositions are also employed, then contacting the porous support material with a cationic polymer and a crosslinker compound may comprise: (i) disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound and a solvent; (ii) removing said solvent; (ia) disposing an intermediate precursor composition on the porous support material, wherein the intermediate precursor composition comprises the crosslinker compound, the cationic polymer and a solvent; (iia) removing said solvent; and optionally repeating steps (ia) and (iia); and (iii) disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer and a solvent. These steps are generally performed in the order (i), (ii), (then optionally (ia) and (iia), with optional repeats of (ia) and (iia) for disposing further intermediate compositions) and then (iii). However, steps (i) and (ii) may overlap, e.g. if a technique such as spin-coating is employed to dispose the crosslinker precursor composition on the porous support material and at the same time cause removal of solvent from said crosslinker precursor composition. Similarly, steps (ia) and (iia) may overlap, e.g. if a technique such as spin-coating is employed to dispose an intermediate precursor composition and at the same time cause removal of the solvent.

[0498] Typically, (i) disposing the crosslinker precursor composition on the porous support material comprises: dipping the porous support material in the crosslinker precursor composition, drop-coating the porous support material with the crosslinker precursor composition, spray-coating the porous support material with the crosslinker precursor composition, or spin-coating the porous support material with the crosslinker precursor composition. Often, it comprises dipping the porous support material in the crosslinker precursor composition. The same preferences apply to step (ia), disposing an intermediate precursor composition.

[0499] The step (ii) of removing said solvent may comprise removing some of said solvent, or, for instance, substantially all of said solvent, or indeed all of said solvent, from the crosslinker precursor composition. Similarly, the step (iia) of removing said solvent may comprise removing some of said solvent, or, for instance, substantially all of said solvent, or indeed all of said solvent, from the intermediate precursor composition. These solvent removal steps are generally performed under conditions that do not cause any of the crosslinker compound to react. Often, therefore, it is performed at ambient temperature. Alternatively, it may be performed at an elevated temperature which is low enough so that none of the crosslinker compound reacts, but high enough to evaporate the solvent (typically a temperature of less than or equal to 80 °C is employed, for instance a temperature of from 40 °C to 80 °C, or from 50 °C to 70 °C). When heating at said elevated temperature is carried out, the heating may be carried out for about 5 to 20 minutes, for instance about 10 minutes. Typically, enough of the solvent is removed to render the disposed crosslinker precursor composition relatively solvent-free, i.e. “dry”. Thus, typically, (ii), removing said solvent comprises removing said solvent to produce a dried crosslinker precursor composition on the porous support material, which dried crosslinker precursor composition comprises the crosslinker compound. In other words, typically, (ii), removing said solvent comprises drying the porous support material with the crosslinker precursor composition disposed thereon. Typically, said drying comprises drying in air, i.e. air-drying. Usually, said air-drying is performed at ambient temperature, and often the airdrying typically comprises leaving the porous support material (with the crosslinker precursor composition disposed thereon) to dry in air. Thus, often, (ii), removing said solvent, comprises airdrying the porous support material with the crosslinker precursor composition disposed thereon for at least 5 minutes, for instance for at least 10 minutes, more typically for at least 20 minutes. Often, the porous support material with the crosslinker precursor composition disposed thereon is air-dried for about 20 minutes. Additionally, or alternatively, in step (ii), the solvent may be removed by using reduced pressure. Similarly, typically, each step (iia), of removing said solvent, comprises removing said solvent to produce a dried intermediate precursor composition, which dried intermediate precursor composition comprises the crosslinker compound and the cationic polymer.

[0500] After step (ii), the dried crosslinker precursor composition, which comprises the crosslinker compound, remains disposed on the porous support material. Thus, in practice, step (ia), of disposing the intermediate precursor composition on the porous support material, comprises disposing the intermediate precursor composition on the dried crosslinker precursor composition (which is in turn disposed on the porous support material). Similarly, in practice, step (iii), of disposing the polymer composition on the porous support material, may comprise disposing the polymer composition on the dried crosslinker precursor composition (which is in turn disposed on the porous support material). Alternatively, step (iii), of disposing the polymer composition on the porous support material, may in practice comprise disposing the polymer composition on the dried intermediate precursor composition (which may in turn be disposed on the dried crosslinker precursor composition, or on another dried intermediate precursor composition).

[0501] The step (iii) of disposing of the polymer composition on the porous support material may comprise dipping the support material in the precursor composition, drop-coating the support material with the precursor composition, spray -coating the support material with the precursor composition, or spin-coating the support material with the precursor composition. As will be appreciated, the support material in these cases will already have the dried crosslinker precursor composition, which comprises the crosslinker compound, disposed thereon, and optionally also one or more dried intermediate precursor compositions, each of which comprises the crosslinker compound and the cationic polymer.

[0502] Optionally, contacting the porous support material with a cationic polymer and a crosslinker compound may further comprise, following step (iii): (iv) removing said solvent (i.e. removing the solvent of the polymer composition). As with step (ii) and (iia), step (iv) may comprise removing some of said solvent, or, for instance, substantially all of said solvent, or indeed all of said solvent, from the polymer composition. The solvent removal step (iv) may be performed under conditions that do not cause any of the crosslinker compound (already disposed on the porous support material) to react. This may be referred to as a drying step. The solvent may be removed using any appropriate means, for instance by using heat and / or reduced pressure, or by allowing the solvent to evaporate over time, e.g. by air-drying as discussed above for steps (ii) and (iia). The solvent may be removed by heating the precursor composition on the support material, for instance at a temperature of less than 100 °C, for instance from 40 °C to 80 °C, or from 50 °C to 70 °C, and for instance the heating may be carried out for about 5 to 20 minutes, for instance about 10 minutes.

[0503] Any of the steps of (i) disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound and a solvent; (ii) removing said solvent; optionally (ia) disposing an intermediate precursor composition on the porous support material, wherein the intermediate precursor composition comprises the crosslinker compound, the cationic polymer and a solvent, and optionally (iia) removing said solvent; (iii) disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer and a solvent; and, optionally, (iv) removing said solvent from the polymer composition, may be carried out more than once (i.e. they may be repeated as necessary) to ensure complete coating of the porous support material, and / or to ensure that the desired thickness of coating is achieved, and / or to ensure that all the pores of the porous support material contain the precursor composition, and / or to ensure that the precursor composition fills all of the pores of the porous support material. In this way, the properties of the anion-conducting composite material (for instance whether or not the composite material is porous, and, if it is porous, the pore size, and for instance the thickness of the resin applied) may be tailored to suit the end use.

[0504] Where the steps of (i) disposing a crosslinker precursor composition on the porous support material and (ii) removing said solvent are repeated, as described above, not each crosslinker precursor composition need be the same. Rather, a first crosslinker precursor composition as defined above and a second crosslinker precursor composition as defined above may have different concentrations of a crosslinker compound. Additionally, or alternatively, a different crosslinker compound may be employed in the first and second crosslinker precursor compositions. Additionally, or alternatively, one of the first and second crosslinker precursor compositions may comprise a further crosslinker compound (or indeed a further cationic compound as defined herein), that is absent from the other crosslinker precursor composition. Often, however, the first and second crosslinker precursor compositions will contain the same components. They may for instance contain the same components but at different concentrations (thus, concentration gradients may be formed).

[0505] Similarly, where the steps of (ia) disposing an intermediate precursor composition on the porous support and (iia) removing said solvent are repeated, as described above, not each intermediate precursor composition need be the same. Rather, a first intermediate precursor composition as defined above and a second intermediate precursor composition as defined above may have different concentrations of a cationic polymer and a crosslinker compound. Additionally, or alternatively, a different cationic polymer and / or crosslinker compound may be employed in the first and second intermediate precursor compositions. Additionally, or alternatively, one of the first and second intermediate precursor compositions may comprise a further cationic compound, or a further crosslinker compound, that is absent from the other intermediate precursor composition. Often, however, the first and second intermediate precursor compositions will contain the same components at different concentrations.

[0506] Similarly, where the steps of (iii) disposing a polymer composition on the porous support material and, optionally, (iv) removing said solvent are repeated, as described above, not each polymer composition need be the same. Rather, a first polymer composition as defined above and a second polymer composition as defined above may have different concentrations of a cationic polymer. Additionally, or alternatively, a different cationic polymer may be employed in the first and second polymer compositions. Additionally, or alternatively, one of the first and second polymer compositions may comprise a further cationic compound, or indeed a further crosslinker compound, that is absent from the other polymer composition. Often, however, the first and second polymer compositions will contain the same components. They may for instance contain the same components but at different concentrations.

[0507] Often, steps (i), (ii) and (iii), and, if performed, the optional steps (ia), (iia) and (iv), result in the porous support material having a coating disposed thereon which comprises a plurality of layers. The coating may comprise a first layer, which is disposed directly on the porous support material and comprises the crosslinker compound, and a second layer which comprises the cationic polymer and may be disposed on the first layer. The layered structure may further comprise one or more intermediate regions, disposed between the first layer and the second layer, wherein each intermediate region comprises the crosslinker compound and the cationic polymer. The “curing” step (b) of the process of the invention usually converts this layered structure into an equivalent layered structure in the composition which comprises the cationic polymer and the reacted crosslinker.

[0508] Similarly, steps (i), (ii) and (iii), and, if performed, the optional steps (ia), (iia) and (iv), may result in the porous support material having a coating disposed thereon which comprises the crosslinker compound and the cationic polymer, wherein the concentration of the crosslinker compound is greater at an inner region of the coating, adjacent a surface of the porous support material, than it is at an outer region of the coating, further away from said surface of the porous support material. Conversely, the concentration of the cationic polymer is typically greater at said outer region than it is at said inner region. In other words, a concentration gradient may result in the coating, wherein the concentration of the crosslinker compound decreases from a relatively high concentration where the coating meets the surface of the porous support material, to a relatively low concentration at the regions of the coating that are farthest away from the surface of the porous support material. Additionally, the concentration of the cationic polymer may increase from a relatively low concentration where the coating meets the surface of the porous support material to a relatively high concentration at the regions of the coating that are farthest away from the surface of the porous support material. The “curing” step (b) of the process of the invention usually preserves this concentration gradient in the resulting composition which comprises the cationic polymer and the reacted crosslinker, in which the concentrations of the cationic polymer and the reacted crosslinker components vary as discussed above for the cationic polymer and crosslinker compound respectively.

[0509] Before, during or after any of steps (i), (ii), (iii) and the optional steps (ia), (iia) and (iv), defined above, the process of the invention may further comprise contacting the porous support material with one or more further cationic compounds.

[0510] Typically, the or each further cationic compound is independently a further cationic polymer or a cationic small molecule. The or each further cationic polymer may be as further defined anywhere herein for the cationic polymer (thus, two or more such cationic polymers may be used).

[0511] The or each cationic small molecule typically comprises a small molecule cation. The small molecule cation may be as further defined hereinbefore, i.e. it may be a quaternary ammonium cation, a quaternary phosphonium cation, a tertiary sulfonium cation, or a heterocyclic cation (for instance a C3-20 heterocyclic cation or a heteroaryl cation) which contains a quaternary nitrogen ring atom. Also, as explained hereinbefore, the or each cationic small molecule typically further comprises a counter anion.

[0512] The one or more further cationic compounds may be included in the above-defined polymer composition which comprises the cationic polymer and / or in the above-defined crosslinker precursor composition which comprises the crosslinker compound, and / or in any of the above-defined one or more intermediate precursor compositions. Alternatively, the one or more further cationic compounds may be disposed on the porous support material separately, either before, during or after contacting the porous support material with the cationic polymer and the crosslinker compound; in other words, either before, during or after steps (i), (ii), (iii) and the optional steps (ia), (iia) and (iv), defined above.

[0513] Often, however, the above-defined polymer composition which comprises the cationic polymer, further comprises one or more further cationic compounds. Thus, the polymer composition may further comprise a further cationic polymer or a cationic small molecule, which may be as further defined above.

[0514] Before, during or after any of steps (i), (ii), (iii) and the optional steps (ia), (iia) and (iv), defined above, the process of the invention may further comprise contacting the porous support material with a further crosslinker compound. It may further comprise contacting the porous support material with a plurality of further crosslinker compounds. The or each further crosslinker compound may be as further defined anywhere herein for the crosslinker compound. The or each further crosslinker compound may for instance be a polymer comprising repeat units of formula (X), or a crosslinker compound of formula (II), as defined herein. Thus, two or more such crosslinker compounds may be used in the process of the invention (namely the crosslinker compound discussed in detail hereinbefore, and the one or more further crosslinker compounds).

[0515] The one or more further crosslinker compounds may be included in the above-defined crosslinker precursor composition which comprises the crosslinker compound and / or in any of the above-defined intermediate precursor compositions. Alternatively, the one or more further crosslinker compounds may be disposed on the porous support material separately, either before, during or after contacting the porous support material with the cationic polymer and the crosslinker compound; in other words, either before, during or after steps (i), (ii), (iii) and the optional steps (ia), (iia) and (iv), defined above. Often, however, the above-defined crosslinker precursor composition which comprises the crosslinker compound, further comprises a further crosslinker compound.

[0516] The further crosslinker compound is different from the crosslinker compound, and may be as further defined anywhere herein for the crosslinker compound. It may for instance be a polymer comprising repeat units of formula (X), or a crosslinker compound of formula (II).

[0517] Thus, in the process of the invention, the crosslinker precursor composition or the polymer composition, or in any of the one or more intermediate precursor compositions, may further comprise:

[0518] - one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer (which may be as further defined herein for the cationic polymer) or a cationic small molecule (which may be as further defined anywhere herein); and / or

[0519] - one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein, for instance a (further) polymer comprising repeat units of formula (X), or a (further) crosslinker compound of formula (II).

[0520] Thus, often:

[0521] - the polymer composition further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or

[0522] - the crosslinker precursor composition further comprises one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein; and / or

[0523] - any of the one or more intermediate precursor compositions further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or

[0524] - any of the one or more intermediate precursor compositions further comprises one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein.

[0525] The crosslinker precursor composition, or any of the one or more intermediate precursor compositions, or the polymer composition may, for instance, further comprise one or more further cationic compounds and one or more further crosslinker compounds. Each of these components may be as further defined anywhere herein.

[0526] Typically, in the process of the invention, disposing the crosslinker precursor composition on the porous support material, optionally disposing one or more intermediate precursor compositions on the porous support material, and disposing the polymer composition on the porous support material comprises coating the porous support material with the crosslinker precursor composition, and then optionally with the one or more intermediate precursor compositions, and then with the polymer composition. Often, in the process of the invention, disposing the crosslinker precursor composition on the porous support material, optionally disposing one or more intermediate precursor compositions on the porous support material, and disposing the polymer composition on the porous support material comprises coating the entire surface of the porous support material with the crosslinker precursor composition, and then optionally with the one or more intermediate precursor compositions, and then with the polymer composition. This typically includes coating the insides of the pores of the porous support material. Indeed, the entire surface, in this context may include the entire external surface of the porous support material and the entire internal surface of the porous support material. Thus, the crosslinker precursor composition, and then optionally the one or more intermediate precursor compositions, and then the polymer composition, may be disposed on the walls of all the pores (meaning all the open pores) within the porous support material as well as on the entire external surface of the porous support material.

[0527] In the process of the invention, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise disposing (or coating) the crosslinker precursor composition, and then optionally the one or more intermediate precursor compositions, and then the polymer composition, in pores of the porous support material. The crosslinker precursor composition, optionally the one or more intermediate precursor compositions, and the polymer composition may or may not be disposed in all of the pores of the porous support material. Often, however, the crosslinker precursor composition, the one or more optional intermediate precursor compositions, and the polymer composition are disposed in all the pores of the porous support material.

[0528] In some preferred embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises filling the pores of the porous support material with the crosslinker precursor composition, the one or more optional intermediate precursor compositions, and the polymer composition. In other embodiments, contacting the porous support material with a cationic polymer and a crosslinker compound comprises partially filling pores of the porous support material with the crosslinker precursor composition, the one or more optional intermediate precursor compositions, and the polymer composition. Additionally, or alternatively, contacting the porous support material with a cationic polymer and a crosslinker compound may comprise filling a first plurality of pores within the porous support material with the crosslinker precursor composition, the one or more optional intermediate precursor compositions, and the polymer composition, and not filling a second plurality of pores within the porous support material with the crosslinker precursor composition, the one or more optional intermediate precursor compositions, and the polymer composition. In this way, the porosity of the final anion-conducting composite material may be controlled, and porous or non-porous anion-conducting composite materials may be prepared.

[0529] Often, in the process of the invention, prior to the step of contacting the porous support material with a cationic polymer and a crosslinker compound, the process further comprises drying the porous support material. Drying the porous support material may for instance comprise drying the porous support material at a temperature of at least 40 °C, or at least 50 °C, for instance at least 60 °C. For instance, the porous support material may be dried at a temperature of from 40 °C to 150 °C, for instance at a temperature of from 50 °C to 90 °C, for instance at a temperature of about 60 °C. The porous support material may be dried at said temperature for at least 30 minutes, for instance at least one hour.

[0530] The process of the invention further comprises (b) generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

[0531] The conditions for decomposition of azide groups to form reactive nitrene intermediate groups, and for hydrazone, diazo or diazirine groups to form reactive carbene intermediate groups are discussed hereinbefore. The carbene or nitrene reactive intermediate groups are typically generated from the reactive intermediate precursor groups by a thermal process and / or by an irradiation process, but can be generated chemically. Typically, the carbene or nitrene reactive intermediate groups are generated by thermal irradiation, for instance by heating. This heat might be applied to the crosslinker compound externally, for example by using a hot press, but may also be as a result of another process, for example, extrusion. Alternatively, the reactive intermediate groups may be generated by electromagnetic radiation, for instance by UV, microwave or laser irradiation, or by ultrasonic irradiation.

[0532] Often, in the process of the invention, the carbene or nitrene reactive intermediate groups are generated by thermal irradiation, for instance by heating. Thus, in the process of the invention, generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups typically comprises heating the crosslinker compound.

[0533] Often, heating the crosslinker compound comprises heating the crosslinker compound under elevated pressure, or while applying pressure. For instance, it may comprise heating the crosslinker compound using a hot press.

[0534] Heating the crosslinker compound often comprises heating the crosslinker compound at a temperature of at least 80 °C, for instance at a temperature of at least 100 °C, for instance at a temperature of from 80 °C to 200 °C, or at a temperature of from 100 °C to 150 °C. Often, heating the crosslinker compound at this temperature comprises heating the crosslinker compound at the temperature while applying pressure to the crosslinker compound, for instance using a hot press.

[0535] The process typically further comprises washing the composite material. The composite material may for instance be washed in a polar solvent, for instance water, typically deionised water. This washing step may help to remove any excess uncured coating. Following said washing, the process may further comprise drying the composite material, for instance drying it at a temperature of from 40 °C to 100°C, for instance from 50 °C to 90 °C. The composite material may be dried at said temperature for a duration of, for instance, 15-120 minutes.

[0536] As discussed hereinbefore, the result of generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups, is that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to bond the cationic polymer to the porous support material. Generally, the carbene or nitrene reactive intermediate groups also crosslink the cationic polymer, which advantageously reduces its solubility in polar solvents including water, preferably to render it insoluble and resistant to solvent swelling.

[0537] Thus, typically, in the process of the invention, the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to bond the cationic polymer to the porous support material. More typically, the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to crosslink the cationic polymer and to bond the cationic polymer to the porous support material.

[0538] In this way, anion-conducting composite materials including anion exchange membranes can be produced at relatively low cost, that can have improved stability (and therefore increased durability in use) compared to materials that are currently available, and also improved anionic conductivity due to the retention of a high concentration of cationic functional groups.

[0539] The process of the invention for producing an anion-conducting composite material may further comprise exchanging a counter-anion of the cationic polymer for a different counter-anion. The different counter-anion may be a hydroxide anion, a carbonate anion or a halide anion. Such a step may be performed after the step (b) of generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups.

[0540] An anion-conducting composite material obtainable by the process

[0541] The invention also provides an anion-conducting composite material which is obtainable by the process of the invention, as defined herein, for producing an anion-conducting composite material.

[0542] The anion-conducting composite material which is obtainable by the process of the invention may be as further defined anywhere herein for the anion-conducting composite material of the invention. Furthermore, the process by which the anion-conducting composite material is obtainable may be as further defined anywhere herein for the process of the invention.

[0543] The invention also provides an anion-conducting composite material which is obtained by the process of the invention, as defined herein, for producing an anion-conducting composite material.

[0544] The anion-conducting composite material which is obtained by the process of the invention may be as further defined anywhere herein for the anion-conducting composite material of the invention. Furthermore, the process by which the anion-conducting composite material is obtained may be as further defined anywhere herein for the process of the invention.

[0545] Polymer comprising repeat units of formula (X)

[0546] The invention also provides a polymer comprising repeat units of formula (X) wherein each E is a carbene precursor group selected from a hydrazone group of formula (A), a diazo group of formula (B), or a diazirine group of formula (C) wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-e alkyl group or an unsubstituted or substituted aryl group; and

[0547] Lxis a spacer group.

[0548] The polymer of the invention which comprises repeat units of formula (X) may be as further defined anywhere herein for the crosslinking compound which is a polymer comprising repeat units of formula (X). Thus, E, R1and Lxin the polymer of the invention, may be as further defined anywhere herein. Furthermore, the repeat units of formula (X) may be repeat units of formula (X’), or repeat units of formula (X”), or the polymer may comprise both repeat units of formula (X’) and repeat units of formula (X”).

[0549] The synthesis of polymers comprising repeat units of formula (X) is described hereinbefore and exemplified in the Examples section herein.

[0550] Processes using the polymer comprising repeat units of formula (X)

[0551] Polymers of the invention comprising repeat units of formula (X) are readily convertible into reactive intermediate carbene groups which can in turn react with a wide variety of substrates, including individual compounds, nanoparticles, microparticles and bulk materials. Such functionalised compounds can be used as agents for creating 3 -dimensional networks within a material or between materials for a wide variety of applications, for instance to produce products in which two or more substrates are adhered, to increase the thermal properties of coating, to alter the rheological properties of a material or to alter the chemical nature of a product such as in producing a particle-delivery compound. The process for carrying out the network formation typically involves the use of a heat cure at a temperature (e.g. 80 °C to 140 °C) which is low enough to allow the process to be carried out on plastic and polymer substrates. Accordingly, the invention provides a process for producing a polymer network bound to one or more substrates, which process comprises:

[0552] (a) contacting one or more substrates with a polymer of the invention which comprises repeat units of formula (X); and

[0553] (b) generating carbene reactive intermediate groups from said carbene precursor groups, so that said carbene reactive intermediate groups react with the one or more substrates to produce said polymer network bound to the one or more substrates.

[0554] In step (a), the one or more substrates may be contacted with the polymer of the invention by any suitable method, depending on the physical forms of the first and second substrates. It may be applied as the neat compound or in solution. Any suitable solvent may be used for the polymer of the invention. Such suitable solvents include but are not limited to alcohols, for instance methanol, methyl ethyl ketone and anisole.

[0555] The one or more substrates may for instance be contacted with the polymer of the invention by dip coating, spray coating, rolling, printing or co-extrusion. The dip coating, spray coating, rolling, printing or co-extrusion may be performed in solution or otherwise. Thus, the dip coating, spray coating, rolling, printing or co-extrusion may be performed using a solution of the polymer of the invention or using the neat polymer. Similarly, the dip coating, spray coating, rolling, printing or co-extrusion may be carried out using the neat substrate(s) or using a suitable solution of the one or more substrates.

[0556] In step (b) of the process of the present invention for producing a polymer network bound to one or more substrates, the generated carbene reactive intermediate groups may react with the surface(s) of the substrates. In this context, the term “surface” means either the whole of the surface of the substrate in question or only a portion of the surface of the substrate.

[0557] The carbene reactive intermediate groups are typically generated by a thermal process, but may be generated chemically or by irradiation. Typically, the carbene reactive intermediate groups are generated by heating. This heat might be applied externally, but may also be as a result of another process, for example, extrusion. Thus, step (b) usually comprises heating the reaction mixture. Typically, the reaction mixture is heated at the reflux temperature of the solvent employed. In some embodiments, the mixture is heated to a temperature of from about 100 °C to about 180 °C, more typically from about 110 °C to 160 °C. When the carbene precursor groups E in the polymer of the invention are sulfonylhydrazone groups, step (b) may alternatively comprise heating the reaction mixture in the presence of a base. Any suitable base may be used, for instance an organic base such as a trialkyl amine (e.g. triethylamine) or l,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Alternatively an inorganic base may be used, such as an alkali metal hydroxide, e.g. sodium, lithium or potassium hydroxide. Typically, the reaction mixture is heated at the reflux temperature of the solvent employed or, for instance, to a temperature of from about 100 °C to about 180 °C, more typically from about 110 °C to 160 °C. When the functionalised compound used is a hydrazone compound in which R1 is H, this conversion may be achieved by oxidation of the hydrazone to a diazomethane followed by the application of energy, typically by heating to said temperature.

[0558] Less typically, the reactive carbene intermediate may be generated by electromagnetic radiation, for instance by UV, microwave or laser irradiation, or by ultrasonic irradiation. Some of these techniques, including laser and UV irradiation, are suitable for generation of the reactive intermediate selectively, i.e. on only a portion of the surface of the first or second substrate.

[0559] The invention is further described in the following examples.

[0560] EXAMPLES

[0561] Synthesis of the Polyimide (PI) polymer which comprises repeat units of formula (X)

[0562] Example 1: PI synthesis via Dean-Stark Method

[0563] Benzophenone-3,3’,4,4’-tetracarboxylic dianhydride (13.54 g, 0.0420 mol) was added to a reaction vessel with overhead stirrer with NMP (N -Methyl -2 -Pyrrolidone) (30 mL). Polypropylene glycol) bis(2 -aminopropyl ether), molecular weight (Mn) ~ 230 Da (10.0 g, 0.0420 mol) in NMP (20 mL) was added dropwise to the reaction vessel. Reaction solution was stirred overnight at room temperature (RT). Toluene was added (5 mL) and the reaction mixture was heated to 170 °C under Dean-Stark conditions. The mixture was cooled to room temperature and product precipitated into methanol.

[0564] The resultant PI product (10.0 g) was added to a round-bottom flask (r.b.f.) along with p- Toluenesulfonyl hydrazide (3.61 g, 19.4 mmol), methanol (~ 5 mL), concentrated sulfuric acid (10 drops) in DCM (50 mL). The reaction mixture was refluxed overnight, then cooled. The solution was washed with DI water, dried with MgSCL, and concentrated by rotary evaporation.

[0565] Example 2: PI Synthesis Prepolymer Method

[0566] Benzophenone-3,3’,4,4’-tetracarboxylic dianhydride (13.54 g, 0.0420 mol) was added to r.b.f. with methanol (50 mL) and stirred at RT with a magnetic stirring. Polypropylene glycol) bis(2- aminopropyl ether), molecular weight (Mn) ~ 230 Da (10.0 g, 0.0420 mol) was added dropwise. Reaction mixture was stirred at RT for 24 hours. Methanol was removed by rotary evaporation. The “prepolymer” was then placed in an oven at 170 °C for 3 hours to complete the ring closing reaction.

[0567] The resultant PI product (10.0 g) was added to an r.b.f. along with p-Toluenesulfonyl hydrazide (3.61 g, 19.4 mmol), methanol (50 mL) and concentrated sulfuric acid (10 drops). The reaction mixture was refluxed overnight, then cooled. The solution was washed with DI water, dried with MgSO4, and concentrated by rotary evaporation. Example 3: Preparation of solutions comprising a crosslinker compound comprising reactive intermediate precursor groups, and a cationic polymer

[0568] Generic solution preparation example

[0569] A carbene or nitrene precursor group containing compound, or a mixture of two or more different carbene or nitrene precursor group containing compounds, is first dissolved in methanol. If two different carbene or nitrene precursor group containing compounds are employed, the weight ratio of one carbene or nitrene precursor compound to the other is typically between 1 : 1 and 6: 1.

[0570] Next, a cationic polymer (for instance a quaternary ammonium or a quaternary phosphonium containing polymer) is added to the solution of the carbene or nitrene precursor containing polymer(s), and the mixture is then stirred using a high-speed homogenizer for 1 minute. Alternatively, a mixture of a cationic polymer and a cationic small molecule can be added to the solution of the carbene or nitrene precursor polymer(s), and the mixture is then stirred using a highspeed homogenizer for 1 minute.

[0571] The total solid content of the final mixture is typically between 20% and 50%

[0572] The carbene or nitrene precursor group containing compound may for instance be a polyimide (PI) polymer comprising repeat units of formula (X), such as the PI polymer comprising repeat units of formula (X’) prepared in Example 1 or Example 2 in which each E is a tosyl hydrazone group of the following formula (AA)

[0573] and each Lxis polypropylene glycol).

[0574] Alternatively, for example, the carbene or nitrene precursor group containing compound may be any crosslinker compound of formula (II) as defined herein. A tosylhydrazone-functionalised polystyrene polymer may for instance be employed, for example a polymer of formula (XXVIc) as defined herein in which Q is polystyrene. The synthesis of such tosylhydrazone-functionalised polystyrene polymers is described in Example 1 on page 142 of WO 2010 / 100410 Al, with reference to Fig. 6 of WO 2010 / 100410 Al.

[0575] The cationic polymer may for instance be Luviquat® Excellence, poly diallyldimethylammonium chloride (pDADMAC), polyvinylbenzyltrimethyl ammonium chloride (pVBTMA), poly( I -methyl -4- vinylpyridinium bromide) or poly(I -methyl -2 -vinylpyridinium bromide).

[0576] Specific coating solution preparation method

[0577] Two coating solutions were prepared, in methanol as the solvent. One coating solution had a total solids content of 25% w / w and the other coating solution had a total solids content of 35% w / w. Both solutions contained polydiallyldimethylammonium chloride (pDADMAC) as the cationic polymer, a single molecule quat (benzyltriethyl ammonium chloride) and, as the crosslinking polymer, tosylhydrazone-functionalised polystyrene. The tosylhydrazone-functionalised polystyrene was prepared as described in Example 1 on page 142 of WO 2010 / 100410 Al, using polystyrene having a molecular weight of 1300 as the base polymer.

[0578] In both methanol solutions, the weight ratio of the cationic polymer to the crosslinking polymer ratio was 1.5 : 1.0 and the weight ratio of the cationic polymer to the single molecule quat was 5: 1. Both solutions were prepared by first dissolving the crosslinking polymer in the methanol, and then adding the cationic polymer and the single molecule quat to the solution. The mixture was stirred and homogenized at 22,000rpm for 1 minute with a high-speed homogenizer. Example 4: Preparation of anion-conducting membrane

[0579] Generic composite preparation example

[0580] • A suitable support mesh made of a material such as nylon or polyethylene is coated with a solution containing a carbene or nitrene precursor compound and a quaternary ammonium polymer by dipping.

[0581] • The coating is dried at 50-70°C for 10 minutes to remove the solvent. The coating may need to be applied more than once to achieve complete coating.

[0582] • The material is cured in a hot press at 120°C and at a pressure setting of 15-25 for 20-30 minutes.

[0583] • After curing the material is washed in deionised water to remove excess uncured coating and dried at 60°C for 30-90 minutes.

[0584] Specific composite preparation method

[0585] • Nylon mesh membrane material with a pore size of 10pm and a porosity of 6% was coated with the specific 25% w / w and 35% w / w solutions prepared in Example 3.

[0586] • The membrane was first coated with the 25% w / w solution by dipping and drying at 70°C for 10 minutes. The material was then coated with a layer of the 35% w / w solution by dipping. Excess coating was removed from the material using a spatula.

[0587] • The material was dried again at 70°C for 10 minutes and then cured in a hot press at 120 °C and at a pressure setting of 20, for 20 minutes. The material was washed in deionised water and then dried at 80°C for 60 minutes.

[0588] Example 5: Preparation of anion-conducting membrane using separate coating solutions: a solution comprising the crosslinker compound and then another solution comprising the cationic polymer, followed by curing

[0589] Membrane Coating

[0590] Quaternary ammonium polymers were dissolved in deionised water to furnish a solution of approximately 0. 1 g / ml concentration. The exact amount of quaternary ammonium polymers varied based on its solid starting solids content.

[0591] Carbene precursor crosslinker (0.2 g) was dissolved in acetone 20 ml to furnish a 0.01 g / mL solution.

[0592] The membranes were first dried at 60 °C for 1 hour and then dipped in carbene precursor crosslinker solution and left to air dry for 20 minutes. The membranes were then dipped in the quaternary ammonium solution and cured at 115 °C for 20 minutes. After curing, any excess unbound material was washed off by soaking in deionised water for 1 hour. The coated membranes were then dried at 60 °C for 1 hour.

[0593] Ion Exchange

[0594] The coated membranes were ion exchanged by soaking the membranes in 0. 1 M sodium hydroxide for 48 or 72 hours. The membranes were then washed with deionised water under vacuum and then soaked in deionised water for 30 minutes. After soaking the membranes were dried at 60 °C for 1 hour in an oven.

[0595] Method for Titration

[0596] The loading of hydroxide is determined by titration against 0.0 IM hydrochloric acid. The membranes were first immersed in lOmL deionised water in a beaker with 10 drops of 0.04M bromothymol blue added as an indicator. The endpoint of the titration is a colour change from blue to yellow in both the solution and the membrane. The loading of hydroxide is then determined from the volume of HC1 required to reach the endpoint using the following equation:

[0597] Glass fibre membrane coating with Poly-DADMAC

[0598] 5g of Poly-DADMAC (20% in water) was dissolved in 5ml of deionised water to furnish a solution of 0. Ig / ml concentration. The exact amount of quaternary ammonium polymers varied based on its solid starting solids content. Carbene precursor crosslinker (0.2g) was dissolved in acetone 20ml to furnish a O.Olg / mL solution. The membranes were first dried at 60°C for 1 hour and then dipped in carbene precursor crosslinker solution and left to air dry for 20 minutes. The membranes were then dipped in the quaternary ammonium solution and cured at 115 °C for 20 minutes. After curing, any excess unbound material was washed off by soaking in deionised water for 1 hour, and the coated membranes were then dried at 60 °C for 1 hour. The coated membranes were ion exchanged with hydroxide before being titrated to determine the hydroxide loading, which is equivalent to the loading of bound quaternary ammonium functionality.

Claims

CLAIMS1. An anion-conducting composite material which comprises:(a) a porous support material; and(b) a composition disposed on the porous support material, wherein the composition comprises:(i) a cationic polymer, and (ii) a reacted crosslinker, wherein the reacted crosslinker is obtainable by generating carbene or nitrene reactive intermediate groups from reactive intermediate precursor groups of a crosslinker compound, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer, wherein the crosslinker compound comprises n of said reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D): whereinan unsubstituted or substituted aryl group.

2. An anion-conducting composite material according to claim 1 wherein the reacted crosslinker bonds the cationic polymer to the porous support material, preferably wherein the reacted crosslinker crosslinks the cationic polymer and bonds the cationic polymer to the porous support material.

3. An anion-conducting composite material according to claim 1 or claim 2 wherein the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to bond the cationic polymer to the porous support material; preferably wherein the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to crosslink the cationic polymer and to bond the cationic polymer to the porous support material.

4. An anion-conducting composite material according to any one of claims 1 to 3 wherein the porous support material contains non-tortuous pores, wherein each non-tortuous pore provides a non- tortuous pathway through the porous support material.

5. An anion-conducting composite material according to any one of the preceding claims wherein the porous support material is a porous membrane, optionally wherein the porous membrane has a thickness of from 1 pm to 500 pm.

6. An anion-conducting composite material according to claim 5 wherein the porous membrane has a mesh structure or a net structure.

7. An anion-conducting composite material according to any one of the preceding claims wherein the porous support material has a porosity of from 0.5 % to 15 % and / or a pore size of from 0.5 pm to 20 pm.

8. An anion-conducting composite material according to any one of the preceding claims wherein the porous support material comprises a polymer, glass or ceramic, optionally wherein the porous support material comprises woven or non-woven fibres which comprise a polymer, glass or ceramic.

9. An anion-conducting composite material according to any one of the preceding claims wherein the porous support material comprises a polymer, optionally wherein the porous support material is a polymer membrane.

10. An anion-conducting composite material according to claim 8 or claim 9 wherein the polymer comprises Nylon, polyphenylene sulphide (PPS), polyethylene, polyetheretherketone (PEEK), polysulfone, polyvinylidene fluoride (PVDF), cellulose or polypropylene.

11. An anion-conducting composite material according to any one of the preceding claims, wherein the cationic polymer comprises covalently-bonded cationic groups.

12. An anion-conducting composite material according to claim 11 wherein the cationic polymer comprises a polymer backbone and the cationic groups are within the polymer backbone or covalently bonded to the polymer backbone.

13. An anion-conducting composite material according to claim 11 or claim 12 wherein the cationic polymer comprises a repeat unit which comprises a covalently-bonded cationic group.

14. An anion-conducting composite material according to any one of claims 11 to 13 wherein the cationic groups are:groups which comprise a quaternary nitrogen atom, optionally wherein the cationic groups are quaternary ammonium groups, quaternary imidazolium groups or quaternary pyridinium groups; or groups which comprise a quaternary phosphorus atom, optionally wherein the cationic groups are quaternary phosphonium groups; or groups which comprise a tertiary sulphur atom, optionally wherein the cationic groups are tertiary sulfonium groups.

15. An anion-conducting composite material according to any one of claims 11 to 14 wherein the cationic polymer comprises repeat units having any of the following formulae:wherein R°, Rp, RQ, RR, Rs, RTand Ruare independently selected from unsubstituted C1.4 alkyl groups, optionally wherein R°, Rp, RQ, RR, Rs, RTand Ruare methyl; optionally wherein the polymer comprises repeat units of formula (Xi) and repeat units of formula (Xv):

16. An anion-conducting composite material according to any one of claims 11 to 15 wherein the cationic polymer further comprises mobile counter-anions, optionally wherein the counter anions are hydroxide anions, carbonate anions or halide anions.

17. An anion-conducting composite material according to any one of claims 11 to 16 wherein the cationic polymer comprises: a copolymer of 3-methyl-l-vinyl-lH-imidazolium chloride and 1-vinyl- 2-pyrrolidinone (for instance, Luviquat® Excellence), polydiallyldimethylammonium chloride (pDADMAC), polyvinylbenzyltrimethyl ammonium chloride (pVBTMA), poly(l -methyl -4- vinylpyridinium bromide) or poly(l -methyl -2 -vinylpyridinium bromide), or any of these polymers in which the chloride or bromide counter anions have been exchanged for hydroxide anions, carbonate anions or anions of a different halide.

18. An anion-conducting composite material according to any one of the preceding claims wherein the composition disposed on the porous support material further comprises:- one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- one or more further reacted crosslinkers, optionally wherein one or more of the further reacted crosslinkers is as defined herein for the reacted crosslinker and / or is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein.

19. An anion-conducting composite material according to any one of the preceding claims wherein the reactive intermediate precursor groups of the crosslinker compound are carbene precursor groups selected from hydrazone groups of formula (A), diazo groups of formula (B) and diazirine groups of formula (C):wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-e alkyl group or an unsubstituted or substituted aryl group, wherein the reacted crosslinker is obtainable by generating carbene reactive intermediate groups from the carbene precursor groups, so that the carbene reactive intermediate groups react with the porous support material and the cationic polymer.

20. An anion-conducting composite material according to any one of claims 1 to 18 wherein the reactive intermediate precursor groups of the crosslinker compound are nitrene precursor groups, which are azide groups of formula (D):wherein the reacted crosslinker is obtainable by generating nitrene reactive intermediate groups from the nitrene precursor groups, so that the nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

21. An anion-conducting composite material according to claim 19 wherein the crosslinker compound is a polymer comprising repeat units of formula (X)whereinE is a carbene precursor group selected from a hydrazone group of formula (A), a diazo group of formula (B), and a diazirine group of formula (C); andLxis a spacer group.

22. An anion-conducting composite material according to claim 21 wherein:E is a hydrazone group of formula (A), optionally wherein R1is -S(O)2R2, and optionally wherein R2is para-tolyl;Lxin each repeat unit of formula (X) is the same or different and is independently selected from unsubstituted or substituted C1-20 alkylene, C1-20 perfluoroalkylene, arylene, heteroarylene and -Ci-20 alkylene -(0-C 1-20 alkylene-)mwherein m is 1 to 500, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, Ci-e alkyl and aryl, optionally wherein Lxin each repeat unit is independently selected from polypropylene glycol (PPG), polyethylene glycol (PEG), unsubstituted C1-6 alkylene and unsubstituted phenylene.

23. An anion-conducting composite material according to any one of claims 1 to 19, 21 and 22 wherein the reacted crosslinker is a polymer comprising repeat units of formula (XX)whereinLxis a spacer group, optionally wherein Lxis as further defined in claim 22;C is a carbon atom;* is a point of attachment of the carbon atom to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition, optionally wherein the other molecule or moiety in the composition is another molecule or moiety of the reacted crosslinker, a further cationic compound or a further reacted crosslinker.

24. An anion-conducting composite material according to any one of claims 1 to 20 wherein the crosslinker compound is a compound of formula (II)wherein:Q is a core moiety, a polymer or a dendrimer; n is an integer equal to or greater than 3; each L, which is the same or different, is a single bond or a linker group; each R, which is the same or different, is a terminal group; and each E, which is the same or different, is one of said reactive intermediate precursor groups, wherein x is 1 and E is a carbene precursor group independently selected from a hydrazone group offormula (A), a diazo group of formula (B) and a diazirine group of formula (C), or wherein x is 0 andE is a nitrene precursor group which is an azide group of formula (D):wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted C1-6 alkyl group or an unsubstituted or substituted aryl group.

25. An anion-conducting composite material according to claim 24 wherein each R, which is the same or different, is selected from hydrogen, aryl, heteroaryl, C1-20 perfluoroalkyl, C1-10 alkoxy, aryloxy, di(Ci-io)alkylamino, alkylarylamino, diarylamino, C1-10 alkylthio, arylthio and CR’3, wherein each R’ is independently selected from a halogen atom, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, heteroaryl, C3-20 carbocyclyl, C3-20 heterocyclyl, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl, triarylsilyl, C2-20 alkenyl, C2-20 alkynyl and C1-20 alkyl, which C1-20 alkyl and C1-20 perfluoroalkyl are optionally interrupted by N(R”), O, S or arylene wherein R”is H, C1-6 alkyl or aryl; provided that when R is aryl or heteroaryl said aryl or heteroaryl may be unsubstituted or substituted by one, two, three, four or five groups, which groups are the same or different and are independently selected from C1-20 alkyl, C2-20 alkenyl, C2-20 alkynyl, C1-20 haloalkyl, C1-20 fluoroalkyl, C1-20 perfluoroalkyl, aryl, cyano, nitro, hydroxy, halo, carboxy, amino, C1-10 alkylamino, di(Ci. io)alkylamino, arylamino, diarylamino, arylalkylamino, amido, acyl, acyloxy, acylamido, ester, C1-10 alkoxy, aryloxy, haloalkyl, thiol, C1-10 alkylthio, arylthio, sulfonic acid, sulfonyl, sulfonamide, tri(Ci-2o alkyl)silyl, aryldi(Ci-2o alkyl)silyl, diaryl(Ci-2o alkyl)silyl and triarylsilyl.

26. An anion-conducting composite material according to claim 24 or claim 25 wherein each L, which is the same or different, is a single bond or a linker group of formula (XII)wherein:A1is bonded to E, wherein, when E is a carbene precursor group and x is 1, A1is bonded to the carbon atom bonded to R, and when E is a nitrene precursor group and x is 0, A1is bonded to an azide group of formula (D), wherein A1is: a single bond or an unsubstituted or substituted group selected from arylene, heteroarylene, Ci-20 perfluoroalkylene, *-0-Ci-2o alkylene, *-0-Ci-2o perfluoroalkylene, *-O-arylene, *-O- heteroarylene, *-N(R”)-CI-2O alkylene, *-N(R”)-CI-2O perfluoroalkylene, *-N(R”) -arylene, *-N(R”)-heteroarylene, *-S-Ci-2o alkylene, *-S-Ci-2o perfluoroalkylene, *-S-arylene, *-S-heteroarylene, *- C(R’)2-CI-2O alkylene, *-C(R’)2-CI-2O perfluoroalkylene, *-C(R’ ^-arylene, *-C(R’)2-heteroarylene and Ci-20 alkylene, wherein each R’ is independently selected from a halogen atom, CMO haloalkyl, CMO fluoroalkyl, CMO perfluoroalkyl, aryl, heteroaryl, C3-10 carbocyclyl, Cs-ioheterocyclyl, tri(Ci-io alkyl)silyl, aryldi(Ci-io alkyl)silyl, diaryl(Ci-io alkyl)silyl, triarylsilyl, C2-10 alkenyl, C2-10 alkynyl and C O alkyl, wherein * is the point of attachment of A1to E, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein R”is independently selected from H, CM alkyl and aryl;A2is a single bond or an unsubstituted or substituted group selected from C1-20 alkylene, C1-20 perfluoroalkylene, arylene, heteroarylene, *-Ci-2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, *-Z1-Ci-2o alkylene, *-Z1-Ci-2o perfluoroalkylene, *-Z’-arylene, *-Z’ -heteroarylene and *-Z1-Ci.2o alkylene-(0-Ci-2o alkylene-)mwherein m is 1 to 20, wherein Z1is selected from O, S, C(O), S(O), S(O)2, N(R”), C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein * is the point of attachment of A2to A1, wherein each of said C1-20 alkylene and C1-20 perfluoroalkylene groups is optionally interrupted by N(R”), O, S or arylene, and wherein each R” is independently selected from H, CM alkyl and aryl; andA3is a single bond or an unsubstituted or substituted group selected from *-Z2-arylene, *-Z2- heteroarylene, *-Z2-CI-2O alkylene, arylene, heteroarylene, C1-20 alkylene, *-Z2-arylene-O, *-Z2- heteroarylene-O, *-Z2-CI-2O alkylene-O, *-arylene-O, *-heteroarylene-O, *-Ci-2o alkylene-O, C(O), S(O)2, *-OC(O), *-N(R”)C(O), O, S, N(R”), *-C(O)O, *-C(O)N(R”), *-S(O)2O, CMO alkenylene, Ci. 20 alkynylene, *-Z2-C O alkenylene and *-Z2-C O alkynylene, wherein Z2is selected from O, S, N(R”), C(O), S(O), S(O)2, C(O)O, OC(O), C(O)N(R”) and N(R”)C(O), wherein each R” is independently selected from H, CM alkyl and aryl, and wherein * is the point of attachment of A3to A2; wherein at least one of A1, A2and A3is not a single bond, optionally wherein A1is not a single bond.

27. An anion-conducting composite material according to any one of claims 1 to 20 and 24 to 26 wherein the reacted crosslinker has the formula (XXVIV)(XXVIV) whereinE’ is a carbon or nitrogen atom; x is 1 when E’ is carbon and x is 0 when E’ is nitrogen;* is a point of attachment of the reacted crosslinker to the porous support material, to the cationic polymer, or to another molecule or moiety in the composition, optionally wherein the other molecule or moiety in the composition is another molecule or moiety of the reacted crosslinker; n is an integer equal to or greater than 3; each R, which is the same or different, is a terminal group, and is optionally as further defined in claim 25; each L, which is the same or different, is a single bond or a linker group, and is optionally as further defined in claim 26; andQ is a core moiety, a polymer or a dendrimer.

28. An anion-conducting composite material according to any one of the preceding claims wherein the composition coats the entire surface of the porous support material.

29. An anion-conducting composite material according to any one of the preceding claims wherein the composition is disposed in pores of the porous support material.

30. An anion-conducting composite material according to any one of the preceding claims wherein the composition fills the pores of the porous support material, so that the anion-conducting composite material is non-porous.

31. An anion-conducting composite material according to any one of claims 1 to 29 wherein the anion conducting composite material is porous.

32. An anion-conducting composite material according to any one of the preceding claims wherein the cationic polymer and the reacted crosslinker are evenly distributed throughout said composition.

33. An anion-conducting composite material according to any one of claims 1 to 31 wherein said composition disposed on the porous support material comprises: a first layer, disposed on the surface of the porous support material, wherein the first layer comprises the reacted crosslinker; and a second layer disposed on the first layer, wherein the second layer comprises the cationic polymer.

34. An anion-conducting composite material according to claim 33 wherein:the first layer does not comprise the cationic polymer, or the concentration of the cationic polymer in the first layer is less than the concentration of the cationic polymer in the second layer; and the second layer does not comprise the reacted crosslinker, or the concentration of the reacted crosslinker in the second layer is less than the concentration of the reacted crosslinker in the first layer.

35. An anion-conducting composite material according to claim 33 or claim 34 wherein the composition disposed on the porous support material further comprises one or more intermediate layers, disposed between the first layer and the second layer, wherein each of the one or more intermediate layers comprises the reacted crosslinker and the cationic polymer.

36. An anion-conducting composite material according to claim 35 wherein, in each of the one or more intermediate layers, the concentration of the cationic polymer is less than the concentration of the cationic polymer in the second layer and greater than the concentration of the cationic polymer in the first layer, and the concentration of the reacted crosslinker is less than the concentration of the reacted crosslinker in the first layer and greater than the concentration of the reacted crosslinker in the second layer.

37. An anion-conducting composite material according to any one of claims 33 to 36 wherein:- the second layer further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- the first layer further comprises one or more further reacted crosslinkers, optionally wherein one or more of the further reacted crosslinkers is as defined herein for the reacted crosslinker and / or is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein; and / or- any of the one or more intermediate layers further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- any of the one or more intermediate layers further comprises one or more further reacted crosslinkers, optionally wherein one or more of the further reacted crosslinkers is as defined herein for the reacted crosslinker and / or is obtainable by generating carbene or nitrene reactive intermediate groups from a crosslinker compound as defined herein.

38. An anion-conducting composite material according to any one of claims 1 to 31 wherein:the concentration of the reacted crosslinker in the composition disposed on the porous support material decreases from a first crosslinker concentration at a region of the composition that is proximal to (and typically in contact with) a surface of the porous support material, to a second crosslinker concentration at a region of the composition that is distal to said surface of the porous support material, wherein the first crosslinker concentration is greater than the second crosslinker concentration; and the concentration of the cationic polymer in the composition disposed on the porous support material decreases from a first polymer concentration at a region of the composition that is distal to a surface of the porous support material, to a second polymer concentration at a region of the composition that is proximal to (and typically in contact with) said surface of the porous support material, wherein the first polymer concentration is greater than the second crosslinker concentration.

39. An anion-conducting composite material according to any one of the preceding claims which is an anion-conducting membrane, optionally wherein the anion-conducting membrane has a thickness of from 1 pm to 500 pm.

40. A process for producing an anion-conducting composite material, which process comprises: (a) contacting a porous support material with a cationic polymer and a crosslinker compound, wherein the crosslinker compound comprises n reactive intermediate precursor groups, wherein n is an integer equal to or greater than 3, wherein the reactive intermediate precursor groups are selected from carbene precursor groups and nitrene precursor groups, wherein the carbene precursor groups are selected from hydrazone groups of formula (A), diazo groups of formula (B), and diazirine groups of formula (C), and the nitrene precursor groups are azide groups of formula (D):wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group; and(b) generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups, so that the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer.

41. A process according to claim 40 wherein the carbene or nitrene reactive intermediate groups react with the porous support material and the cationic polymer to bond the cationic polymer to the porous support material, preferably wherein the carbene or nitrene reactive intermediate groups reactwith the porous support material and the cationic polymer to crosslink the cationic polymer and to bond the cationic polymer to the porous support material.

42. A process according to claim 40 or claim 41 wherein: the crosslinker compound is as further defined in any one of claims 19 to 22 and 24 to 26; the porous support material is as further defined in any one of claims 4 to 10; the cationic polymer is as further defined in any one of claims 11 to 17; and / or the anion-conducting composite material is as further defined in any one of claims 28 to 39.

43. A process according to any one of claims 40 to 42 wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing a precursor composition on the porous support material, wherein the precursor composition comprises the cationic polymer and the crosslinker compound.

44. A process according to claim 43 wherein the precursor composition further comprises:- one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein.

45. A process according to claim 43 or claim 44 wherein the precursor composition further comprises a solvent, and wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing the precursor composition on the porous support material and removing the solvent, optionally wherein disposing the precursor composition on the porous support material comprises dipping the support material in the precursor composition, drop-coating the support material with the precursor composition, spray -coating the support material with the precursor composition, or spin-coating the support material with the precursor composition, and optionally wherein the process further comprises repeating, once or more than once, the steps of disposing the precursor composition on the porous support material and removing the solvent.

46. A process according to any one of claims 43 to 45 wherein disposing the precursor composition on the porous support material comprises coating the entire surface of the porous support material with the precursor composition, including the insides of the pores of the porous support material, optionally wherein disposing the precursor composition on the porous support material comprises filling the pores of the porous support material with the precursor composition.

47. A process according to any one of claims 40 to 46 wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: disposing a crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound, and subsequently disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer.

48. A process according to claim 47 wherein: the crosslinker precursor composition does not comprise the cationic polymer, or the concentration of the cationic polymer in the crosslinker precursor composition is less than the concentration of the cationic polymer in the polymer composition; and the polymer composition does not comprise the crosslinker compound, or the concentration of the crosslinker compound in the polymer composition is less than the concentration of the crosslinker compound in the crosslinker precursor composition.

49. A process according to claim 47 or claim 48 wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound further comprises, after disposing the crosslinker precursor composition but before disposing the polymer composition: disposing one or more intermediate precursor compositions on the porous support material, wherein each intermediate precursor composition comprises said crosslinker compound and said cationic polymer.

50. A process according to claim 49 wherein, in each of the one or more intermediate precursor compositions, the concentration of the cationic polymer is less than the concentration of the cationic polymer in the polymer composition and greater than the concentration of the cationic polymer in the crosslinker precursor composition, and the concentration of the crosslinker compound is less than the concentration of the crosslinker compound in the crosslinker precursor composition and greater than the concentration of the crosslinker compound in polymer composition.

51. A process according to claim 47 or claim 48 wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: (i) disposing the crosslinker precursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound and a solvent; (ii) removing said solvent; and (iii) disposing the polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer and a solvent; and, optionally, (iv) removing the solvent of the polymer composition.

52. A process according to claim 49 or claim 50 wherein (a) contacting the porous support material with a cationic polymer and a crosslinker compound comprises: (i) disposing the crosslinkerprecursor composition on the porous support material, wherein the crosslinker precursor composition comprises the crosslinker compound and a solvent; (ii) removing said solvent; (ia) disposing an intermediate precursor composition on the porous support material, wherein the intermediate precursor composition comprises the crosslinker compound, the cationic polymer and a solvent; (iia) removing the solvent of the intermediate precursor composition; optionally repeating steps (ia) and (iia); (iii) disposing a polymer composition on the porous support material, wherein the polymer composition comprises the cationic polymer and a solvent; and, optionally, (iv) removing the solvent of the polymer composition.

53. A process according to any one of claims 47 to 52 wherein:- the polymer composition further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- the crosslinker precursor composition further comprises one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein; and / or- any of the one or more intermediate precursor compositions further comprises one or more further cationic compounds, wherein each further cationic compound is independently a further cationic polymer or a cationic small molecule; and / or- any of the one or more intermediate precursor compositions further comprises one or more further crosslinker compounds, optionally wherein one or more of the further crosslinker compounds is a crosslinker compound as further defined herein.

54. A process according to any one of claims 40 to 53 wherein (b) generating carbene or nitrene reactive intermediate groups from the reactive intermediate precursor groups comprises heating the crosslinker compound, optionally to a temperature of at least 100 °C, and optionally while applying pressure.

55. A process according to any one of claims 40 to 54 wherein the process further comprises exchanging a counter-anion of the cationic polymer for a different counter-anion, optionally wherein the different counter-anion is a hydroxide anion, a carbonate anion or a halide anion.

56. An anion-conducting composite material which is obtainable by a process according to any one of claims 40 to 55.

57. A polymer comprising repeat units of formula (X)each E is a carbene precursor group selected from a hydrazone group of formula (A), a diazo group of formula (B), or a diazirine group of formula (C)wherein R1is H or -S(O)2R2, and R2is an unsubstituted or substituted Ci-6 alkyl group or an unsubstituted or substituted aryl group; andLxis a spacer group, optionally wherein Lxis as further defined in claim 22.

58. A process for producing a polymer network bound to one or more substrates, which process comprises:(a) contacting one or more substrates with a polymer as defined in claim 57; and(b) generating carbene reactive intermediate groups from said carbene precursor groups, so that said carbene reactive intermediate groups react with the one or more substrates to produce said polymer network bound to the one or more substrates.

59. Use of an anion-conducting membrane as defined in claim 39 as an anion exchange membrane.

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