Quinone-containing polyureas and polyurethanes as redox-active materials

Abstract

A quinone-containing polymer comprising repeating units of at least one of Formulas (I) to (III), as defined herein. Methods of manufacturing the quinone-containing polymer are also disclosed. The quinone-containing polymer can be useful in composites, electrode assemblies, electrochemical cells, gas separation systems, energy storage devices, and electrochromic devices.

Description

QUINONE-CONTAINING POLYUREAS AND POLYURETHANES AS REDOX-ACTIVEMATERIALSCROSS-REFERENCE TO RELATED APPLICATIONThis application claims priority to U.S. Provisional Application No. 63 / 561,943, filed on March 6, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is hereby incorporated by reference in its entirety.BACKGROUND

[0001] Removing target species from gas mixtures has been the subject of much research and development. For example, there have been efforts to mitigate global warming by curbing carbon dioxide emissions. To this end, a number of approaches, such as thermal methods have been explored, to capture carbon dioxide at different stages of its production. Other potential applications of target gas removal include removing target gases directly from air or ventilated air.

[0002] Electro-swing adsorption (ESA) is an alternative method of capturing a target gas from a gaseous mixture. Typically, the electrode in an electro-swing adsorption cell includes an electrically conductive scaffold and an electroactive material. There remains a need for improved materials for electro-swing adsorption, including improved methods of production.SUMMARY

[0003] A quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III) Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci -30 alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups; provided that when the quinone-containing polymer is a homopolymer according to Formula (I) and when Q is a single bond or -NR’-, X is -NH- or -S-.

[0004] Another aspect of the present disclosure is a method of making the quinone- containing polymer, the method including polymerizing a dihydroxy naphthoquinone, a dihydroxy benzoquinone, a dihydroxy anthraquinone, a diamino naphthoquinone, a diamino benzoquinone, a diamino anthraquinone, a dithio benzoquinone, a dithio anthraquinone, a dithio naphthoquinone, or a combination thereof, with a diisocyanate under conditions effective to provide the quinone-containing polymer.

[0005] Another aspect of the present disclosure is a composite comprising a quinone- containing polymer disposed on a substrate, wherein the quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III) Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a C6-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.

[0006] Another aspect is an electrode assembly comprising a porous separator; and the composite on a surface of the porous separator, in a pore of the porous separator, or a combination thereof.

[0007] Another aspect is an electrochemical cell comprising the composite.

[0008] Another aspect is a gas separation system comprising a plurality of electrochemical cells in fluid communication with a gas inlet and a gas outlet.

[0009] Another aspect is an energy storage device comprising the quinone-containing polymer, the composite, or the electrochemical cell.

[0010] Another aspect is an electrochromic device comprising the quinone-containing polymer, the composite, or the electrochemical cell.

[0011] A method for separating a target gas from a fluid mixture comprising the target gas, the method comprising contacting the fluid mixture with a quinone-containing polymer, wherein the quinone-containing polymer is in a reduced state, to form an anion adduct betweenthe target gas and the quinone-containing polymer in the reduced state; wherein the quinone- containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III) Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci -30 alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.

[0012] The above described and other features are exemplified by the detailed description.DETAILED DESCRIPTION

[0013] Incorporation of quinones into macromolecules has drawn attention because the resulting redox-active polymers provide active materials with useful properties for electrochemical devices, including energy storage devices and electro-swing absorption (ESA)separation. Disclosed herein are polyurethanes or polyureas derived from quinones difunctionalized with nucleophilic groups, such as alcohols or amines, reacted with diisocyanates. These polymers retain the electrochemical properties of the parent quinones while having desirable physical properties, making them attractive for incorporation into composite electrodes.

[0014] Known synthetic routes to quinone-containing polymers often rely on radical mechanisms or have limited substrate scope. In an advantageous feature, the disclosed polymerizations can be performed under mild conditions, are readily scalable, and allow for facile incorporation of functional co-monomers. Accordingly, the methods of manufacturing the quinone-containing polymer disclosed herein are synthetically versatile and can accommodate varied monomer designs, such as those described below. The quinone-containing polymer can also be prepared without the use of a transition metal catalyst, improving cost, scalability, and functional group tolerance and monomer scope.

[0015] Accordingly, an aspect of the present disclosure is a quinone-containing polymer. The polymer can include repeating units of at least one of Formulas (I), (II), or (III):

[0016] In Formulas (I) to (III), Q can be independently at each occurrence a single bond, -O-, -S-, -NR’- wherein R’ can be hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L can be independently at each occurrence a single bond, a C&-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X can be independently at each occurrence -O- or -NH-; A can be independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or acombination thereof; and R can be independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group (e.g., a carboxylic acid, an ester, an amide, or a ketone), a thiol group, or a vinyl group; n can be 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups. When the quinone-containing polymer is a homopolymer according to Formula (I) and when Q can be a single bond or -NR’-, X is -NH- or -S-. It will be understood that when an adjacent Q and L are both are a single bond, X is bonded directly to the quinone. For example, for a moiety *-Q-L-X-(C=O))NH-* wherein each “*” represents a point of attachment to the rest of the molecule, when Q and L are both a single bond, X is bonded directly to the quinone (or to the one or more additional fused substituted or unsubstituted aryl groups, when present).

[0017] In an aspect, L can independently at each occurrence be a single bond, a substituted or unsubstituted C1-6 alkylene group, a substituted or unsubstituted C6-30 arylene group, a substituted or unsubstituted C1-6 alkylene glycol group, or a combination thereof. In an aspect, L can be an unsubstituted phenylene group.

[0018] In an aspect, A can be an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a combination thereof. In a specific aspect, A can be an alkylarylene group or an arylalkylene group. For example, A can be a methyl benzene or a methylene diphenylene group.

[0019] In an aspect, the quinone-containing polymer can have repeating units of at least one of Formulas (IV) to (XXII):

[0020] In Formulas (IV) to (XXII), R1to R9can independently at each occurrence be hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group,a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a Ci-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group (e.g., a carboxylic acid, an ester, an amide, or a ketone), a thiol group, or a vinyl group.

[0021] In an aspect, the quinone-containing polymer can include repeating units according to any of Formulas (FV)-(IX). In an aspect, the quinone-containing polymer can include repeating units according to any of (X)-(XIII). In an aspect, the quinone-containing polymer can include repeating units according to any of (XIII)-(XXII).

[0022] In an aspect, at least 10 mole percent, or at least 20 mole percent, or at least 30 mole percent, or at least 40 mole percent, or at least 50 mole percent, or at least 75 mole percent, or at least 80 mole percent, or at least 90 mole percent, or at least 95 mole percent, or at least 99 mole percent, e.g., 50 mole percent to 99.9 mole percent, or 75 mole percent to 95 mole percent, of the repeating units are according to at least one of Formulas (I) to (III). In an aspect, the quinone-containing polymer is a homopolymer consisting of repeating units according to Formulas (I), (II), or (III).

[0023] The quinone-containing polymer can optionally include repeating units different than the repeating units of Formulas (I) to (III). The repeating units different than the repeating units of Formulas (I) to (III) can be derived from a diamine co-monomer, a diol co-monomer, or dithiol co-monomer. The diamine co-monomer can be a substituted or unsubstituted aromatic diamine, the diol co-monomer can be a substituted or unsubstituted aromatic diol, the dithiol comonomer can be a substituted or unsubstituted aromatic dithiol.

[0024] The diamine co-monomer, the diol co-monomer, or the dithiol co-monomer can be substituted with a crosslinkable group. Crosslinkable groups can include functional groups which are triggered by heat, radiation, or a chemical trigger suitable for forming a crosslinked network comprising the quinone-containing polymer. The crosslinkable group can generally be any functional group capable of participating in a chemical reaction with a complementary functional group. Crosslinks formed from the crosslinkable groups can include ionic bonds, covalent bonds, or a combination thereof. The crosslinkable group can include, but is not limited to, an alpha-diazo ester group, a vinyl group, an azido group, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an isocyanato group, a halide, an aluminum salt, or a combination thereof.

[0025] When present, the repeating units different than the repeating units of Formulas (I) to (III) can be present in an amount of at most 90 mole percent, or at most 80 mole percent, or at most 70 mole percent, or at most 60 mole percent, or at more 50 mole percent, or at most 25 mole percent, or at most 20 mole percent, or at most 10 mole percent, or at most 5 molepercent, each based on total moles of all repeating units in the quinone-containing polymer. For example, the repeating units different than the repeating units of Formulas (I) to (III) can be present in an amount of 5 to 25 mole percent, or 10 to 20 mole percent, each based on total moles of all repeating units in the quinone-containing polymer.

[0026] The quinone-containing polymer can include at least 5 repeating units according to at least one of Formulas (I) to (III), or at least 10 repeating units according to at least one of Formulas (I) to (III). The quinone-containing polymer can have a number average molecular weight of 1,000 to 200,000 grams per mole (g / mol), or 2,500 to 200,000 g / mol, or 5,000 to 200,000 g / mol, or 10,000 to 200,000 g / mol, or 10,000 to 100,000 g / mol, or 10,000 to 75,000 g / mol, or 20,000 to 50,000 g / mol. In an aspect, the quinone-containing polymer can have a number average molecular weight of 1,000 to 50,000 grams per mole, or 1,000 to 25,000 grams per mole, or 1,000 to 10,000 grams per mole. Molecular weight can be determined, for example, using gel permeation chromatography (GPC) in tetrahydrofuran or dimethylformamide relative to polystyrene standards.

[0027] A method of making the quinone-containing polymer represents another aspect of the present disclosure. The method of making the quinone-containing polymer can include polymerizing a dihydroxy naphthoquinone, a dihydroxy benzoquinone, a dihydroxy anthraquinone, a diamino naphthoquinone, a diamino benzoquinone, a diamino anthraquinone, a dithio benzoquinone, a dithio anthraquinone, a dithio naphthoquinone, or a combination thereof, with a diisocyanate under conditions effective to provide the quinone-containing polymer.

[0028] Polymerizing can optionally be performed in the absence of a catalyst. Alternatively, the polymerizing can be in the presence of a catalyst. Suitable catalysts can include tertiary amines and metal compounds based on tin, bismuth, and zinc. Tertiary amine catalysts include triethylenediamine (TEDA, l,4-diazabicyclo[2.2.2]octane or DABCO), dimethylcyclohexylamine (DMCHA), dimethylethanolamine (DMEA), and N-ethylmorpholine. Specific metal compounds include bismuth and zinc carboxylates, organotin compounds (including dibutyltin dilaurate and tin carboxylates such as stannous octoate), oxides of tin, bismuth and zinc, and mercaptides of tin, bismuth, and zinc.

[0029] The polymerizing can be performed in a dry solvent. “Dry solvent”, as used herein, refers to a solvent with less than 1000 parts per million (ppm) of water. The dry solvent can be a polar, aprotic solvent. Examples of polar, aprotic solvents include dimethylsulfoxide (DMSO), tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dioxane, and the like.

[0030] The conditions effective to provide the quinone-containing polymer can include a temperature of 20°C to 100°C and a time of 1 minute to 24 hours, 10 minutes to 24 hours, or 30 minutes to 24 hours, or 1 hour to 5 hours, or 2 hours to 3 hours.

[0031] The diisocyanate can be readily available and in some instances commercially available. The diisocyanate can include an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a combination thereof as a linking group between the two isocyanate functional groups. Examples of suitable diisocyanates include 4,4'- methylenebis(phenyl isocyanate) (MDI), hexamethylene diisocyanate (HMDI or hydrogenated MDI), tolylene-2,4-diisocyanate (TDI), isophorone diisocyanate, and the like.

[0032] The method can optionally further comprise isolating the quinone-containing polymer. Isolation of the quinone-containing polymer can be by, for example, precipitation by addition of an excess of a nonsolvent. An exemplary nonsolvent can include, for example, methanol. Following precipitation, the quinone-containing polymer can be isolated by any solid-liquid separation technique which is generally known, for example, filtration or centrifugation.

[0033] Polymer products can be characterized by nuclear magnetic resonance (NMR) spectroscopy, ultraviolet (UV)-visible spectroscopy, infrared (IR) spectroscopy, and gel permeation chromatography (GPC).

[0034] A composite including a quinone-containing polymer represents another aspect of the present disclosure. The composite can comprise the quinone-containing polymer as described above disposed on a substrate.

[0035] The quinone-containing polymer can be disposed on at least a portion of a surface of the substrate. In an aspect, the substrate can be impregnated with the quinone-containing polymer. In an aspect, one or more intervening layers can be positioned between the substrate and the quinone-containing polymer. In an aspect, no intervening layers are present and the quinone-containing polymer can be disposed directly on a surface of the substrate. In an aspect, the substrate can comprise a carbonaceous material. Exemplary carbonaceous material can include, but are not limited to, carbon paper (treated, TEFLON-treated, or untreated), carbon cloth, nonwoven carbon mat, or a nonwoven carbon nanotube mat. In an aspect the substrate can comprise a nonwoven carbon nanotube mat, for example as described in co-pending International Application No. PCT / US2021 / 049751, the contents of which is incorporated by reference in its entirety for all purposes. In an aspect, the substrate can comprise vertically aligned carbon nanotubes, for example as described in co-pending U.S. Patent Application No. 18 / 035,807, the contents of which is incorporated by reference in its entirety for all purposes.

[0036] The quinone-containing polymer can be referred to as being immobilized on the substrate such that the quinone-containing polymer is not capable of freely diffusing away from or dissociating from the substrate. The quinone-containing polymer can be immobilized on the substrate in a variety of ways. For example, the quinone-containing polymer can be immobilized on the substrate by being bound (e.g., via covalent bonds, ionic bonds, or intramolecular interaction such as electrostatic forces, van der Waals forces, hydrogen bonding, or a combination thereof) to the surface of the substrate. In an aspect, the quinone-containing polymer can be immobilized on the substrate by being adsorbed onto a surface of the substrate. In an aspect, the quinone-containing polymer can be immobilized on the substrate. Immobilizing the quinone-containing polymer can include, but is not limited to, grafting or polymerizing the quinone-containing polymer onto a surface of the substrate. “Grafting” as used herein refers to a chemical or electrochemical process producing a covalent bond between the quinone-containing polymer and the substrate. In an aspect, the quinone-containing polymer can be immobilized on the substrate by being included in a composition, e.g., a coating or a composite layer that is applied or deposited onto the substrate. Immobilizing the quinone- containing polymer can also include electrodeposition, plasma deposition, vacuum infiltration, melt coating, or a combination of any of the foregoing. In an aspect, the quinone-containing polymer of the composite can be at least partially crosslinked.

[0037] The thickness of the quinone-containing polymer on the surface of the substrate can be, for example, 0.1 to 20 nanometers, or 0.2 to 15 nanometers, or 0.5 to 10 nanometers. The thickness of the quinone-containing polymer on the surface of the substrate can depend on the mode of deposition.

[0038] The composite can optionally be porous. For example, the composite can have a porosity of at least 20%, preferably 30 to 60%.

[0039] The composite can comprise the quinone-containing polymer in an amount of 1 to 90 weight percent, based on the total weight of the composite. Within this range, the quinone-containing polymer can be present in an amount of at least 2 weight percent, or at least 5 weight percent, or at least 7 weight percent, or least 10 weight percent, at least 20 weight percent, or at least 25 weight percent, or at least 30 weight percent, or least 40 weight percent, or at least 50 weight percent, based on the total weight of the composite. Also, within this range, the quinone-containing polymer can be present in an amount of at most 85 weight percent, or at most of at most 80 weight percent, or at most 70 weight percent, or at most 60 weight percent, or at most 50 weight percent, or at most 45 weight percent, or at most 40 weight percent. Forexample, the quinone-containing polymer can be present in an amount of 1 to 75 weight percent, or 5 to 60 weight percent, or 7 to 25 weight percent, based on the total weight of the composite.

[0040] The quinone-containing polymers of the present disclosure can be useful for a variety of electrochemical applications. For example, the quinone-containing polymers described herein can be used for energy storage, electrochromic applications, catalysis, and gas separation.

[0041] An electrode assembly represents another aspect of the present disclosure. In an aspect, the electrode assembly comprises the composite as described above and a porous separator. The composite can be disposed on the porous separator, optionally with one or more intervening layers disposed between the composite and the porous separator. In an aspect the composite can be laminated to the porous separator. The porous separator can comprise any suitable material. In an aspect, the porous separator can comprise a polymer film, for example a film comprising a polyamide, a polyolefin, a polyaramid, a polyester, a polyurethane, an acrylic resin, and the like, or a combination thereof. The polymer may be coated on one or both sides with ceramic nanoparticles. In an aspect, the porous separator can comprise cellulose, a synthetic polymeric material, or a polymer / ceramic composite material. Further examples of separators can include polyvinylidene difluoride (PVDF) separators, polytetrafluoroethylene (PTFE), PVDF-alumina composite separators, and the like.

[0042] In an aspect, the electrode assembly can comprise a patterned electrode, for example as described in co-pending U.S. Application No. 17 / 345,074 and in co-pending International Application No. PCT / US2021 / 016636, the contents of both of which are incorporated by reference in their entirety for all purposes.

[0043] An electrochemical cell comprising the composite represents another aspect of the present disclosure. The electrochemical cell can comprise a first electrode comprising the above-described composite comprising the quinone-containing polymer, a second electrode comprising a complementary electroactive composite layer, and a first separator disposed between the first electrode and the second electrode.

[0044] The separator can be as described above for the electrode assembly. The separator can serve as a protective layer that can prevent the respective electrochemical reactions at each electrode from interfering with each other. The separator can also help electronically isolate the first and second electrodes from one another or from other components within the electrochemical cell to prevent a short-circuit. A person of ordinary skill, with the benefit of this disclosure, would be able to select a suitable separator.

[0045] The electrochemical cell can further comprise an electrolyte. The electrolyte can have a suitable conductivity at room temperature (e.g., 23 °C). In an aspect the separator can be partially or completely impregnated with the electrolyte. Impregnating the separator with the electrolyte can be by submerging, coating, dipping, or otherwise contacting the separator with the electrolyte. Some or all of the pores of the porous separator can be partially or completely filled with the electrolyte. In an aspect, the separator can be saturated with the electrolyte.

[0046] In an aspect the electrolyte comprises an ionic liquid, for example a room temperature ionic liquid (RTIL). Ionic liquids can have low volatility, for example a vapor pressure of less than 10'5Pa, or IO"10to 10‘5Pa at a temperature of 23°C, which can reduce the risk of the separator drying out and allow for reduction in loss of the electrolyte due to evaporation of entrainment. In an aspect the ionic liquid accounts for substantially all (e.g., at least 80 volume percent, or at least 90 volume percent, or at least 95 volume percent, or at least 98 volume percent, at least 99 volume percent, or at least 99.9 volume percent) of the electrolyte.

[0047] The ionic liquid comprises an anion component and a cation component. The anion of the ionic liquid can comprise, but is not limited to halide, sulfate, sulfonate, carbonate, bicarbonate, phosphate, nitrate, nitrate, acetate, PF 6, BF4, triflate, nonaflate, bis(trifluoromethylsulfonyl)amide, trifluoroacetate, heptafluorobutanoate, haloaluminate, triazolide, or an amino acid derivative (e.g., proline with the proton on the nitrogen removed). The cation of the ionic liquid can comprise one or more of, but is not limited to, imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, sulfonium, thiazolium, pyrazolium, piperidinium, triazolium, pyrazolium, oxazolium, guanadinium, an alkali cation, or dialkylmorpholinium. In an aspect, the room temperature ionic liquid comprises an imidazolium as a cation component. In an aspect, the room temperature ionic liquid comprises l-butyl-3- methylimidazolium (“Bmim”) as a cation component. In an aspect, the room temperature ionic liquid comprises bis(trifluoromethylsulfonyl)imide (“TFSI”) as an anion component. In an aspect, the room temperature ionic liquid comprises l-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (“[Bmim] [TFSI]”). In an aspect, the room temperature ionic liquid comprises l-butyl-3-methylimidazolium tetrafluoroborate (“BF4”) (“[Bmim][BF4]”).

[0048] In an aspect the electrochemical cell of the present disclosure can comprise a first electrode, a second electrode, a separator disposed between the electrodes, and an electrolyte as disclosed above, wherein the quinone-containing polymer of the present disclosure can be dissolved in the electrolyte.

[0049] The second electrode of the electrochemical cell comprises a complementary electroactive composite layer. The complementary electroactive composite layer can be the same or different from the composite comprising the quinone-containing polymer of the present disclosure. The complementary electroactive composite layer comprises an electroactive species which can be the same or different as the quinone-containing polymer of the composite of the first electrode.

[0050] In an aspect, the complementary electroactive composite layer comprises the same quinone-containing polymer as the composite of the first electrode. In an aspect, the complementary electroactive composite layer comprises an electroactive species which is different from the quinone-containing polymer of the composite of the first electrode (“a second electroactive species”). The second electroactive species can serve as a source of electrons for the reduction of the first electroactive species present in the first electrode. Likewise, the second electroactive species may serve as a sink for electrons during oxidation of the first electroactive species. The second electroactive species can comprise, for example, polyvinyl ferrocene, poly(3-(4-fluorophenyl)thiophene), or other Faradaic redox species with a reduction potential at least 0.5 volts more positive that the first reduction potential of the first electroactive species (e.g., the quinone-containing polymer of the present disclosure).

[0051] In an aspect, the second electrode can further comprise a substrate, which can be positioned proximate to or between complementary electroactive composite layers. The substrate can be in direct or indirect contact with the complementary electroactive composite layer or layers. When present, the substrate can include, for example, carbon paper (treated, TEFLON-treated, or untreated), carbon cloth, nonwoven carbon mat, or a nonwoven carbon nanotube mat. In an aspect, the support can comprise the same carbonaceous material of the composite of the first electrode. In an aspect, the substrate of the second electrode can be a conductive material and act as a current collector within the electrochemical cell.

[0052] In an aspect, the first electrode can be a negative electrode, and the second electrode can be a positive electrode. The terms negative electrode and positive electrode are used for convenience and clarity, although they may be technically accurate only when the target gas is being acquired or released.

[0053] In an aspect, the second electrode can be positioned between first electrodes. Each of the first electrodes can comprise the disclosed composite. In an aspect the first electrodes and / or second electrodes can be identical in configuration or composition.

[0054] In an aspect, the electrochemical cell comprises a single separator, disposed between the first electrode and the second electrode, e.g., between the negative electrode and thepositive electrode. The separator can serve as a protective layer that can prevent the respective electrochemical reactions at each electrode from interfering with each other. The separator can also help electronically isolate the first and second electrodes from one another or from other components within the electro-swing adsorption cell to prevent a short-circuit. A person of ordinary skill, with the benefit of this disclosure, would be able to select a suitable separator.

[0055] In an aspect, the electrochemical cell comprises a single separator, disposed between the first electrode and the second electrode, e.g., between the negative electrode and the positive electrode. Electrochemical cells can be combined to make a stack in any suitable combination of parallel and series configurations. In an aspect, the electrochemical cell can comprise more than one separator. For example, one of skill in the art would understand that depending on the selected combination of series and parallel configurations, a single separator may be used, or a plurality of separators may be preferred.

[0056] The separator can be a porous separator. The porous separator can comprise any suitable material. In an aspect, the porous separator can comprise a polymer film, for example a film comprising a polyamide, a polyolefin, a polyaramid, a polyester, a polyurethane, an acrylic resin, or a combination thereof. The polymer may be coated on one or both sides with a ceramic nanoparticle. In an aspect, the porous separator can comprise cellulose, a synthetic polymeric material, or a polymer / ceramic composite material. Further examples of separators can include polyvinylidene difluoride (PVDF) separators, polytetrafluoroethylene (PTFE), PVDF-alumina composite separators, or a microporous olefin, such as a microporous polyethylene or microporous polypropylene.

[0057] The electrochemical cell can further comprise a current collector which conducts electrons from the electrode to the adjacent cell (in series-stacked configurations) or from the electrode to a terminal connection (in parallel-stacked configurations). The current collector can comprise, for example, carbon, a metal, or a combination thereof. In an aspect, the current collector can comprise carbon. Suitable examples of the carbon can include, but are not limited to, graphite, flaked graphite, expanded graphite, carbon fiber, carbon nanotubes, amorphous carbon, graphene, or a combination thereof. The carbon nanotubes may comprise single-wall carbon nanotubes or multi-wall carbon nanotubes. Carbon nanotubes are primarily carbon, although the nanotube fiber may further comprise other atoms, such as boron, nitrogen, or one or more of various metals. In an aspect, the current collector can comprise a metal. The metal can comprise Fe, Zn, Ti, Cu, Al, Ni, Mg, Sn, Cr, Mn, Au, Mo, W, In, V, Nb, Ag, an alloy or intermetallic thereof, or a combination thereof. In an aspect the alloy is a stainless steel, such as 304 or 316 stainless steel.

[0058] In an aspect, the carbon or metal may have a spherical, flake, or fibrous morphology. In an aspect, the metal may be in the form of a metal mesh, foam, felt, or an expanded metal. The carbon or metal particles can be oriented. For example, when the metal is in the form of a fiber, the fibers can be oriented such that a long axis is oriented in a direction perpendicular to a major surface of the current collector, e.g., such that the fiber is oriented orthogonal to the surface, e.g., in a through-plane direction.

[0059] In an aspect, the current collector can comprise a composite comprising the carbon, the metal, and a binder. The carbon or metal in the composite can be present in an amount of 10 to 98 vol%, based on the total volume of the composite. In an aspect, the composite comprises the carbon or the metal in an amount of 50 to 95 vol%, based on the total volume of the composite. In an aspect, the composite comprises carbon nanotubes or graphene and can include the carbon nanotubes or graphene in an amount of 10 to 40 vol%, based on the total volume of the composite. The composite may comprise a pore, and the pore may contain a polymer.

[0060] The binder, when present, can comprise a polymer. The binder can be a thermoset or a thermoplastic. Suitable polymer binders can include, for example, an epoxy, a phenolic, a vinyl ester, a polyarylene sulfide, a polybenzoxazine, an isocyanate, a fluoropolymer, a rubber, or a combination thereof. Representative polymer binders can include polyacrylic acid (PAA), polyvinylidene difluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene-rubber, or a fluorinated rubber. A combination comprising one of the foregoing polymer binders may be used.

[0061] The binder can optionally further include an additive. Specific additives can include flow promoters, mold release agents, or a combination thereof. In an aspect, the polymer binder can be crosslinked. The polymer can be an electrical insulator or an electrical conductor. An exemplary electrically conducting polymer can be found, for example, in U.S. Publication No. 2004 / 977797, the contents of which are incorporated by reference herein in their entirety for all purposes. Optionally, a conductive material such as carbon black, nanotubes, carbon fiber, graphene, and the like can be embedded in the polymer binder at a surface of the current collector, which, without wishing to be bound by theory, is believed to reduce the contact resistance to an adjacent cell component such as to the gas diffusion layer.

[0062] In an aspect, the current collector can optionally comprise a coating disposed on at least a portion of a surface of the current collector. The coating can, without wishing to bebound by theory, serve to reduce corrosion, block ion or gas permeation, or improve electrical contact to the gas-diffusion layer or electrode. The coating, when present, can comprise carbon, a metal, an alloy, or an intermetallic material, or a combination thereof, wherein the metal, alloy, or intermetallic material comprises Ni, Zn, Ti, Sn, Au, V, Mo, Cr, or a combination thereof. The coating can comprise an oxide, boride, nitride, or carbide of a metal, alloy, or intermetallic. Nonlimiting examples of coating compositions can include tin oxide, titanium carbide, tungsten carbide, zirconium carbide, indium tin oxide, indium zinc oxide, titanium boride, zirconium boride, titanium niobium oxide, titanium tantalum oxide, lanthanum strontium chromium oxide, lanthanum strontium cobalt oxide, titanium nitride, chromium nitride, vanadium nitride, or a combination thereof. For example, in an aspect, the current collector can be plated with a metal, such as Fe, Ni, or Au, or a corrosion-resistant material such as TiN. In an aspect, the coating can comprise a polymer. An example of a polymer coating is described, for example, in U.S. Publication No. 2007 / 0298267, the contents of which are incorporated by reference herein in their entirety for all purposes. In an aspect, the coating can comprise an electrically conducting polymer. In an aspect, the coating can comprise the binder as described above, and particles of a conductive material, such as carbon black, carbon nanotubes, graphene, gold, silver, or a combination thereof. In an aspect, the coating comprises vapor-deposited diamond-like carbon, or a product of pyrolysis of a carbonaceous polymer.

[0063] The current collector may have any suitable porosity, and in an aspect is nonporous. In an aspect, the current collector is effectively impervious to a target gas, e.g., carbon dioxide.

[0064] The electrochemical cell may be stacked in series, and the current collector may block transport of ions and of reactant and released gas from a first cell to a second neighboring cell. Furthermore, the current collector can impart mechanical structure and stability to an electrochemical cell. The current collector can optionally comprise ribs which form channels which provide a flowfield for distribution of the gas across the cell. The rib may conduct electrons across the electrochemical cell and optionally provide desirable structural integrity. The rib, when present, can comprise, for example, carbon, a metal, a composite, or a combination thereof, as disclosed above, and can optionally include the coating, each of which is further described above. The rib may comprise the same material as the current collector. The rib may comprise a different material from the current collector. The rib may comprise a material which can be partially compressed, in order to accommodate manufacturing thickness tolerances. For example, the rib may comprise an electronically-conductive closed-cell foam or gasket. The ribs may be convex or concave portions relative to the surface of the currentcollector and can have any suitable cross-sectional shape, for example a rectangular or rounded shape.

[0065] In an aspect, a first side of the current collector can face an adsorbent electrode (e.g., the first electrode), and a second, opposite side of the current collector faces a nonadsorbent counter electrode (e.g., the second electrode) or an end plate. In an aspect, both sides of the current collector can face adsorbent electrodes. The side of the current collector which faces an adsorbent electrode may comprise a flow field. The sides of the current collector, e.g., the first side and the second side, can each independently comprise the same or a different material. In an aspect, an intervening layer comprising a barrier material, such as a material which is electrically conductive and can block the transport of ions or gas, can be interposed between the first and second sides of the current collector. In an aspect, the barrier material can comprise a metal foil.

[0066] The current collector can include a feature to aid with sealing the perimeter of the apparatus. Such features can include grooves, steps, bevels, or a combination thereof. Such features are described, for example, in U.S. Publication No. 2002 / 0197519, the contents of which are incorporated by reference herein in their entirety for all purposes.

[0067] The current collector can further comprise a channel extending through the interior of the current collector, preferably through which coolant can flow. The coolant channel can be arranged so that the coolant flow rate is highest in the region of the cell expected to have the highest rate of heat generation, as can be readily determined by one of ordinary skill in the art. Use of a parallel or serpentine configuration is mentioned. In an aspect in which a foam or mesh, such as an electrically conductive foam or mesh, is used, the coolant can flow through the foam or mesh. The foam or mesh may be provided between two layers of the current collector. In an aspect, the coolant can flow through a corrugated or waveform structure, provided between opposite layers of the current collector.

[0068] In an aspect, the current collector can comprise a first sheet that contains a channel for reactant gas flow on a first face, and a channel for coolant on a second, opposite face. The first sheet can be attached to a second sheet, which forms a boundary for the coolant channels while providing electrical conduction orthogonal to the face of the sheets. The first sheet can be attached to the second sheet by any suitable method, for example, brazing, welding, soldering, laminating, diffusion bonding, compression, or adhesive bonding. The coolant channels can be formed by nesting adjacent plates, which contain flow-fields for the first and second electrodes. Coolant channels are described in U.S. Patent No. 6,099,984, and further exemplary coolant flow patterns can be found in provided in U.S. Publication Nos.2004 / 0209150 and 2003 / 0203260, the contents of each of which are incorporated by reference herein in their entirety for all purposes.

[0069] The current collector can further comprise a sensor, e.g., a voltage sensor or a voltage sensing wire connected to the current collector. In an aspect, the current collector can further comprise a heating element.

[0070] In an aspect, the current collector can comprise members to facilitate assembly, such as alignment pins. Alternatively, a frame may be provided at a periphery of the current collector to aid alignment or sealing. Examples of various suitable current collector components can be found in U.S. Publication No. 2003 / 0022052, the contents of which are incorporated by reference herein in their entirety for all purposes.

[0071] The electrochemical cell can optionally further comprise a gas flow field. The gas flow field, when present, can be positioned between the first electrode and the current collector. When the gas diffusion layer is not present in the electrochemical cell, the gas flow field can be positioned adjacent to the first electrode, on a side opposite the separator. In an aspect, the gas flow field can be positioned adjacent to a current collector or a side of the current collector may comprise a flow field. The flow field can comprise structures for directing the reacting fluid to flow from a flow inlet to a flow outlet. Without wishing to be bound by theory, the flow field serves to provide uniform reactant flow to the electrode area. Preferably, the flow field provides uniform reactant flow to the electrode area, a low barrier to flow e.g., a low pressure drop, and suitable electrical conduction from the electrode through the flow field to the current collector.

[0072] The gas flow field can optionally further comprise a gas diffusion layer. The gas diffusion layer can be positioned adjacent to the first electrode, on a side opposite the separator. The gas diffusion layer can comprise a porous, electrically conductive material. In an aspect, the gas diffusion layer has a porosity, for example, of greater than or equal to 60%, greater than or equal to 70%, greater than or equal to the 75%, greater than or equal to 80%, or greater. In an aspect, the gas diffusion layer has a porosity of less than or equal to 85%, less than or equal to 90%, or more. Combinations of these ranges are possible. For example, in an aspect, the gas diffusion layer of the first electrode has a porosity of greater than or equal to 60% and less than or equal to 90%. Other porosities are also possible. Examples of suitable materials for the gas diffusion layer include, without limitation, carbon paper (treated, PTFE-treated, or untreated), carbon cloth, or a nonwoven carbon fiber or carbon nanotube mat.

[0073] In an aspect, the flow field can comprise a porous foam or mesh. The foam or mesh can be bonded to a nonporous plate by a conductive adhesive, welding, heat-bonding, or sintering.

[0074] The flow field can comprise a channel. The channel can be defined by two or more ribs. In an aspect, the channels, the ribs, or both can each independently have average widths of at least 0.1 millimeter (mm), at least 0.2 mm, at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.8 mm, at least 0.9 mm, at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, or at least 9 mm. In an aspect, the channels, the ribs, or both can each independently have average widths of no more than 10 mm, no more than 9 mm, no more than 8 mm, no more than 7 mm, no more than 6 mm, no more than 5 mm, no more than 4 mm, no more than 3 mm, no more than 2 mm, no more than 1 mm, no more than 0.9 mm, no more than 0.8 mm, no more than 0.7 mm, no more than 0.6 mm, no more than 0.5 mm, no more than 0.4 mm, no more than 0.3 mm, or no more than 0.2 mm. Combinations of the above-referenced average widths for the channels and / or the ribs are also possible.

[0075] In an aspect, the channels, the ribs, or both can each independently have average depths of at least 0.1 mm, at least 0.2 mm, at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.8 mm, at least 0.9 mm, at least 1 mm, at least 2 mm, or at least 3 mm. In an aspect, the channels, the ribs, or both can each independently have average depths of no more than 4 mm, no more than 3 mm, no more than 2 mm, no more than 1 mm, no more than 0.9 mm, no more than 0.8 mm, no more than 0.7 mm, no more than 0.6 mm, no more than 0.5 mm, no more than 0.4 mm, no more than 0.3 mm, or no more than 0.2 mm. Combinations of the abovereferenced average depths for the channels and / or the ribs are also possible.

[0076] Various methods for manufacturing a flow field may be used, e.g., machining, injection molding, compression molding, extruding, embossing, or stamping. Exemplary methods are described, for example, in U.S. Publication No. 2004 / 0151975 and U.S. Publication No. 2003 / 0022052, the contents of each of which are incorporated by reference herein in their entirety for all purposes. In an aspect, the flow field can comprise a corrugated metal with couplings to route the flow from one channel to a neighboring channel, for example as described in U.S. Publication No. 2002 / 0081477, the contents of which are incorporated by reference herein in their entirety for all purposes.

[0077] A flow pattern of the flow field can have any suitable configuration, e.g., to provide parallel, serpentine, or interdigitated flow. Non-limiting examples of serpentine flow patterns are provided in U.S. Patent No. 6,309,773, the contents of which are incorporated byreference herein in their entirety for all purposes. Flow channels can have a uniform crosssection or can have regions which are tapered or constricted, e.g., to provide a suitable distribution of reactant across the cell area. The flow channels may contain a disruption or obstacle, e.g., to generate turbulence which can improve transport of reactants into the electrode. Exemplary flow channels are described in U.S. Patent No. 6,756,149, the contents of which are incorporated by reference herein in their entirety for all purposes. The flow field pattern and dimensions can be the same for each flow field in a cell, or they can vary depending on the position of the cell within the stack and the nature of the electrode facing the flow field, as can be readily determined by a skilled person. In an aspect, when channels on both faces of the current collector are present, the channels can be nested to reduce the thickness of the stack.

[0078] In an aspect, a manifold can be used to deliver a process gas, e.g., a reactant gas, to the electro-swing adsorption cell, and to convey a product gas, e.g., a released gas, away from the electro-swing adsorption cell. The manifold can distribute the gas. Parameters such as manifold length and cross-sectional dimensions can be selected to provide suitable properties, such as pressure drop. The manifold can also preferably prevent leakage of the gas. Exemplary manifold designs that can be used include but are not limited to those disclosed in U.S. Patent Nos. 6,159,629; 6,174,616; 5,486,430; 5,776,625; and 6,017,648; the contents of each of which are incorporated by reference herein in their entirety for all purposes.

[0079] In an aspect, the electrochemical cell can include a seal to prevent leakage of process gases out of the electro-swing adsorption cell. The surface facing the seal region, e.g., a surface of the gas-diffusion layers, electrodes, or separators, can be impregnated at their periphery with a gas-impermeable sealant. Preferably, the geometry of the seal is selected such that stress that can result in puncture, fatigue, or tearing of the separator is not introduced. The thickness of the seal can be uniform or can vary across different regions of the seal with respect to the edge of the electrode and the gas diffusion layer. The seal is electrically insulating and chemically and electrochemically unreactive. The seal can comprise a suitable o-ring, gasket, or adhesive. The seal can comprise a ridge or bead of fluid-impermeable material deposited on the periphery of a member, such as the current collector or manifold. In an aspect, the seal can comprise an elastomer, and can be a thermoset or a thermoplastic, for example, an epoxy, a rubber, a polyolefin, a silicone, a fluoropolymer, a fluoro-elastomer, or a chloropolymer. In an aspect, the seal can comprise a foam, for example a foamed rubber. In an aspect, the seal can comprise a heat-shrinkable film. Exemplary seal materials are described in U.S. Patent No. 6,440,597 and U.S. Publication No. 2006 / 0073385, the contents of each of which are incorporated by reference herein in their entirety for all purposes.

[0080] In an aspect, when the seal is a gasket, the gasket can optionally comprise a filler, which preferably can provide a coefficient of thermal expansion of the gasket material that is matched to that of the adjacent material, e.g., the current collector material. Exemplary fillers can include, but are not limited to, glass, polystyrene, poly(tetrafluoroethylene) (PTFE), or an insulating metal oxide such as silica or alumina.

[0081] Suitable seals can be manufactured by any suitable method, e.g., injecting a bonding polymer into a groove around the edge of the cell, for example as described in U.S. Publication No. 2003 / 0031914, the contents of which are incorporated by reference herein in their entirety for all purposes. The method can comprise forming grooved surfaces with correspondingly shaped gaskets, for example as described in U.S. Publication No. 2003 / 0072988, the contents of which are incorporated by reference herein in their entirety for all purposes. In an aspect, the sealant material can be coated, sprayed, laminated, or injection molded onto the current collector or onto an assembly of the gas diffusion layer, electrodes, separator, or a combination thereof. The sealant can encapsulate the exterior-facing edges of the cell. Examples of seal geometries are described in U.S. Publication Nos. 2007 / 0231619, 2007 / 0042254, and 2002 / 0172852, and U.S. Patent No. 6,261,711, the contents of each of which are incorporated by reference herein in their entirety for all purposes. In an aspect, a gasket on opposite sides of the separator can be connected to each other through through-holes optionally included in a peripheral region of the separator.

[0082] To improve sealing, in an aspect the separator can be nonporous in the periphery region. A method of rendering the separator nonporous comprises hot-pressing the separator at a temperature sufficient to cause the material (e.g., a polymeric material) of the separator to flow, thereby filling the pores. The separator can be hot-pressed or thermally bonded to a gasket, or adhered with a sealant.

[0083] It can be advantageous to remove heat from the electrochemical cell to prevent the internal temperature from exceeding temperatures that can damage the electrochemical cell. Heat removal can be achieved through the use of coolant channels, discussed previously. In an aspect, the electrochemical cell can be cooled by blowing air over a side of the electrochemical cell. In an aspect, the electrochemical cell can be cooled by flowing coolant through tubes or ducts alongside a side or within the electrochemical cell. In an aspect, the current collector can be devoid of any coolant channels, and cooling can be provided by controlling the flow rate of a process gas through the electrochemical cell, effectively using the process gas as a coolant. This cooling method can be particularly advantageous if the process gas (reactant gas) is air.

[0084] In an aspect, at least a portion of the electrochemical cell can be heated. For example, an end portion of the electrochemical cell can be heated, or the cells at the ends of the electrochemical cell (e.g., the “end cells”) can be heated. Without wishing to be bound by theory, heating the electrochemical cell can enable higher capture rate or prevent water condensation from a humid process gas. Electrical-resistance heating elements can be incorporated or disposed adjacent to an end plate or a manifold, for example.

[0085] Applying pressure across an electrochemical cell can be advantageous to reduce contact resistance between components within the electrochemical cell e.g., contact resistance between the flow field and the gas diffusion layer. Application of pressure can also be advantageous to improve seal hermeticity. Pressure can be applied across an electrochemical cell, for example, using tie rods or external clamps. A tie rod can be internal or external to the seals and manifolds. It can be preferable to apply pressure uniformly, without localized regions of mechanical stress that can lead to mechanical failure. Those skilled in the art will be familiar with the design of washers, disc springs, coiled springs, belleville washers, nuts, clamps, frames, fasteners, collets, wedges, or pressure plates to apply uniform pressure and avoid stress concentration. Examples of compression assemblies are described in, for example, U.S. Patent No. 6,190,793, the contents of which are incorporated by reference herein in their entirety for all purposes.

[0086] The quinone-containing polymer of the present disclosure can be reactive towards a target gas. The target gas is an electrophilic molecule. In an aspect, the target gas is a Lewis acid gas or a Bronsted acid gas, preferably a Lewis acid gas. The target gas is capable of forming a complex or an adduct with the quinone-containing polymer when the quinone- containing polymer is in a reduced state, for example, by bonding to the quinone-containing polymer in its reduced state. The target gas can comprise carbon dioxide (CO2), a sulfur oxide species such as sulfur dioxide (SO2) or sulfur trioxide (SO3), an organosulfate (R2SO4, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl) such as dimethyl sulfate, a nitrogen oxide species such as nitrogen dioxide (NO2) or nitrogen trioxide (NO3), a phosphate ester (R3PO4, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl) such as trimethyl phosphate, an ester (RCOOR' where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl, and each R' is independently C1-12 alkyl or C6-20 aryl) such as methyl formate or methyl acrylate, an aldehyde (RCHO, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl ) such as formaldehyde or acrolein, a ketone (R2CO, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl) such as acetone, an isocyanate (RNCO, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl, and each R' is independently C1-12 alkyl or C6-20 aryl) such as methylisocyanate, isothiocyanate (RNCS, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl, and each R' is independently C1-12 alkyl or C6-20 aryl), a borane (BR3, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl) such as trimethyl borane, or a borate (R3BO3, where each R is independently hydrogen, C1-12 alkyl, or C6-20 aryl) such as trimethyl borate. The target gas can optionally comprise a combination of any of the foregoing target gas species.

[0087] In an aspect, the quinone-containing polymer in a reduced state can have a binding constant with a target gas (e.g., carbon dioxide) of at least 101M1, preferably 101to 1020M’1, more preferably 103to 1020. In an aspect, a binding constant with a target gas may be 103to IO20M’1, 105to 1018M’1, or 108to 1015M’1.

[0088] As such, an electrochemical cell comprising the quinone-containing polymer can be particularly useful for the separation of a target gas from a gas mixture when the gas mixture is contacted with the electrochemical cell, and thus is particularly well suited for use in a gas separation system. The gas separation system comprises a plurality of electrochemical cells in fluid communication with a gas inlet and a gas outlet.

[0089] The gas mixture, also referred to as the input gas, can be at least partially separated upon exposure to the electrochemical cell. The gas mixture can be, for example, ambient air (e.g., air from an ambient environment, such as outdoor air). In an aspect, the gas separation system can be used for direct air capture. The systems and methods described herein can be useful for removing a target gas such as carbon dioxide directly from ambient air (e.g., to reduce greenhouse gas levels), without the need for any pre-concentration step. Certain aspects of the present disclosure can make the systems and methods described herein particularly useful for direct air capture (e.g., an ability to bond with a target gas while being thermodynamically disfavored from reacting with major component-s of ambient air, such as oxygen).

[0090] In an aspect, the concentration of the target gas in the gas mixture is relatively low, for example when the gas mixture is ambient air. For example, the concentration of the target gas in the gas mixture prior to exposure to the electrochemical cell can be less than or equal to 500 ppm, or less than or equal to 450 ppm, or less than or equal to 400 ppm, or less than or equal to 350 ppm, or less than or equal to 300 ppm, or less than or equal to 200 ppm. In an aspect, the concentration of the target gas in the gas mixture can be as low as 100 ppm, or as low as 50 ppm, or as low as 10 ppm.

[0091] In an aspect, the gas mixture (e.g., input gas mixture) is ventilated air. The ventilated air can be air in an enclosed or at least partially enclosed place (e.g., air being circulated in an enclosed place). Examples of places in which the gas mixture (e.g., ventilatedair) can be located include, but are not limited to sealed buildings, partially ventilated places, car cabins, inhabited submersibles, aircrafts, and the like.

[0092] The concentration of target gas in the ventilated air can be higher than ambient air but lower than concentrations typical for industrial processes. In an aspect, the concentration of the target gas in the gas mixture prior to exposure to the electrochemical cell is less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, or less than or equal to 2,000 ppm, or less than or equal to 1,000 ppm. In an aspect, the concentration of the target gas in the gas mixture (e.g., when it is ventilated air / air in enclosed spaces) is as low as 1,000 ppm, or as low as 800 ppm, or as low as 500 ppm, or as low as 200 ppm, or as low as 100 ppm, or as low as 10 ppm.

[0093] In an aspect, the gas mixture comprises oxygen gas (O2). In an aspect, the gas mixture has a relatively high concentration of oxygen gas (e.g., prior to exposure to the electrochemical cell). Certain aspects of the systems and methods described herein (e.g., the choice of particular electroactive species, methods of handling gases in the system, etc.) can contribute to an ability to capture target gases in gas mixtures in which oxygen gas is present without deleterious interference. In an aspect, oxygen gas is present in the gas mixture (e.g., prior to exposure to the electrochemical cell) at a concentration of greater than or equal to 0 volume percent, or greater than or equal to 0.1 volume percent, or greater than or equal to 1 volume percent, or greater than or equal to 2 volume percent, or greater than or equal to 5 volume percent, or greater than or equal to 10 volume percent, or greater than or equal to 20 volume percent, or greater than or equal to 50 volume percent, or greater than or equal to 75 volume percent, or greater than or equal to 90 volume percent, greater than or equal to 95 volume percent. In an aspect, oxygen gas is present in the gas mixture at a concentration of less than or equal to 99 volume percent, or less than or equal to 95 volume percent, or less than or equal to 90 volume percent, or less than or equal to 75 volume percent, or less than or equal to 50 volume percent, or less than or equal to 25 volume percent, or less than or equal to 21 volume percent, or less than or equal to 10 volume percent, or less than or equal to 5 volume percent, or less than or equal to 2 volume percent.

[0094] In an aspect, the gas mixture comprises water vapor. The gas mixture can comprise water vapor for example, because it is or comprises ambient air or ventilated air. In an aspect, the gas mixture (e.g., prior to exposure to the electrochemical cell) has a relatively high relative humidity. For example, in an aspect, the gas mixture can have a relative humidity of greater than or equal to 0%, or greater than or equal to 5%, or greater than or equal to 10%, or greater than or equal to 25%, or greater than or equal to 50%, or greater than or equal to 75%, or greater than or equal to 90% at least one temperature in the range of -50 to 140°C. In an aspect,the gas mixture can have a relative humidity of less than or equal to 100%, or less than or equal to 95%, or less than or equal to 90%, or less than or equal to 75%, or less than or equal to 50%, or less than or equal to 25%, or less than or equal to 10% at least one temperature in the range of -50 to 140°C.

[0095] The target gas can be separated from the gas mixture in the gas separation system by applying a potential difference across the electrochemical cells of the gas separation system. One of ordinary skill, with the benefit of this disclosure, would understand how to apply a potential across the electrochemical cell. For example, the potential can be applied by connecting the negative electrode and the positive electrode to a suitable power source capable of polarizing the negative and positive electrodes. In an aspect the power supply can be a DC voltage. Nonlimiting examples of a suitable power source include batteries, power grids, regenerative power supplies (e.g., wind power generators, photovoltaic cells, tidal energy generators), generators, and the like, and combinations thereof.

[0096] The potential difference can be applied to the electrochemical cells during at least a portion of the time that a gas mixture is exposed to the electrochemical cell. In an aspect, the potential difference can be applied prior to exposing the gas mixture to the electrochemical cell.

[0097] Application of a positive voltage to the electrochemical cell, during a charging mode, results in a redox reaction at the negative electrode wherein the quinone-containing polymer is reduced. As discussed herein, the quinone-containing polymer is selected for having a higher affinity for the target gas when it is in a reduced state relative to when it is in an oxidized state. By reducing the quinone-containing polymer and passing a gas mixture across the first electrode, the target gas can bond to the quinone-containing polymer. In this way the target gas can be removed from the gas mixture to provide a treated gas mixture (e.g., comprising a lesser amount of the target gas relative to the initial gas mixture).

[0098] The potential difference applied across the electrochemical cell, during the charge mode, can have a particular voltage. The potential difference applied across the electrochemical cell can depend, for example, on the reduction potential for the generation of at least one reduced state of the first electroactive species, as well as the standard potential for the interconversion between a reduced state and an oxidized state of the quinone-containing polymer in the second electrode. The voltage further includes the current multiplied by the stack electrochemical resistance. In an aspect, the potential difference is at least 0 volts (V), or at least 0.1 V, or at least 0.2 V, or at least 0.5 V, or at least 0.8 V, or at least 1.0 V, or at least 1.5 V. In an aspect, the potential difference is less than or equal to 2.0 V, or less than or equal to 1.5 V, or less than or equal to 0.5 V, or less than or equal to 0.2 V.

[0099] In an aspect, for example when the quinone-containing polymer is reduced to at least one of its reduced states in the presence of a target gas, for example carbon dioxide, the reduced form of the quinone-containing polymer can bond with the carbon dioxide.

[0100] In an aspect, while the quinone-containing polymer is reduced at the first electrode, an electroactive species (e.g., a redox active polymer such as polyvinyl ferrocene) is being oxidized at the second electrode. During the charge mode, the oxidation of the electroactive species provides a source of electrons for driving the reduction of the quinone- containing polymer.

[0101] While the exemplary reaction shown above is shown taking place in one direction, it will be understood that some reversibility can be exhibited. Analogous reaction can take place with different electroactive species, as would be understood by a person of ordinary skill in the art.

[0102] In an aspect, a relatively large amount of the target gas is removed from the gas mixture during the processes described herein. Removing a relatively large amount of the target gas can, in some cases, be beneficial for any of a variety of applications, such as capturing gases that can be deleterious if released into the atmosphere for environmental reasons. For example, the target gas can comprise carbon dioxide, and removing a relatively high amount of the carbon dioxide from gas mixture can be beneficial to either limit the greenhouse gas impact of a process (e.g., an industrial process or transportation process) or to even reduce the amount of carbon dioxide in a room or the atmosphere (either for thermodynamic reasons for heating and air conditioning processes or for environmental reasons).

[0103] In an aspect the amount of target gas in a treated gas mixture (e.g., a gas mixture from which an amount of the target gas is removed upon being exposed to the electrochemical cell) is less than or equal to 50%, less than or equal to 25%, less than or equal to 10%, less than or equal to 5%, less than or equal to 2%, less than or equal to 1%, less than or equal to 0.5%, less than or equal to 0.1% of the amount (in volume percent) of the target gas in the original gas mixture prior to treatment (e.g., the amount of the target in the gas mixture prior to being exposed to electrochemical cell). In an aspect, the amount of target gas in a treated gas mixture is greater than or equal to 0.001%, greater than 0.005%, greater than or equal to 0.01%, greater than or equal to 0.05%, greater than or equal to 0.1%, greater than or equal to 0.5%, greater than or equal to 1%, greater than or equal to 2%, greater than or equal to 5% of the amount (in volume percent) of the target gas in the original gas mixture prior to treatment.

[0104] In an aspect, a second potential difference can be applied across the electrochemical cell after at least a portion of the target gas is bonded to the quinone-containingpolymer. The second potential difference can be different than that first potential difference. In an aspect, applying the second potential difference results in a step of releasing a portion or all of the target gas bonded with the quinone-containing polymer to produce a second treated gas mixture. The second treated gas mixture can have a greater amount of the target gas than the input gas mixture. For example, target gas may be present in the second treated gas mixture in an amount such that its content is 10 volume percent (vol%), 20 vol%, 50 vol%, 100 vol%, 200 vol%, 1000 vol%, and / or up to 2,000 vol%, 5,000 vol%, 10,000 vol%, or more than the content in the first gas mixture.

[0105] The gas separation system can comprise an external circuit connecting the negative electrode and the positive electrode of each electrochemical cell to a power source configured to apply a potential difference across the negatives electrode and the positive electrode of each electrochemical cell. Each of the electrochemical cells of the gas separation system can be as described above. The electrochemical cells of the gas separation system can be stacked according to various configurations that are generally known in the art, including parallel or in series.

[0106] In an aspect, a gas separation system comprises a first set of electrochemical cells and a second set of electrochemical cells. Each of the first set and the second set can comprise one or more electrochemical cells as described throughout this disclosure. The first and second set can be made to run in parallel in an alternating fashion, such that one set of cells is operating in a charge mode and capturing a target gas (e.g., CO2) from a gas mixture while another set of cells is operating in a discharge mode and releasing the target gas (e.g., CO2). The system can comprise separate housings for each of the sets of electrochemical cells. The system can further comprise conduits and valving arranged to direct flow in a desired manner. The gas separation system can allow for nearly continuous separation of a gas mixture (e.g., gas stream), with the gas mixture being directed to the set of cells operating in a charge / capture mode, at a given moment, while a separate target gas-rich treated mixture is produced by the other set of cells operating in a discharge / release mode. Furthermore, additional sets of electrochemical cells may be added in parallel or in series, according to the needs of the application.

[0107] The gas mixture (e.g., a gas stream such as an input gas stream) can be introduced to the gas separation system at a particular flow rate. In an aspect, the flow rate can be greater than or equal to 0.001 liter per second (L / s), greater than or equal to 0.005 L / s greater than or equal to 0.01, greater than or equal to 0.05 L / s, greater than or equal to 0.1 L / s, greater than or equal to 0.5 L / s, greater than or equal to 1 L / s, greater than or equal to 5 L / s, greater than or equal to 10 L / s, greater than or equal to 10 50 L / s, or greater than or equal to 100 L / s. In anaspect, the flow rate of the gas mixture (e.g., a gas stream such as an input gas stream) can be less than or equal to 500 L / s, less than or equal to 400 L / s, less than or equal to 300 L / s, less than or equal to 200 L / s, less than or equal to 100 L / s, less than or equal to 50 L / s, less than or equal to 10 L / s, less than or equal to 1 L / s, less than or equal to 0.5 L / s, or less than or equal to 0.1 15 L / s. Suitable combinations of the foregoing ranges are mentioned.

[0108] In an aspect, during or after the step of releasing the target gas, the method further comprises applying a vacuum condition to the electrochemical cell to remove at least a portion or all of the released target gas from the electrochemical cell. One of ordinary skill, with the benefit of this disclosure, would understand suitable techniques and equipment for applying a vacuum condition to the electrochemical cell. For example, a vacuum pump can be fluidically connected to a gas outlet of the electrochemical cell. The vacuum pump can be operated to produce a negative pressure differential between the electrochemical cell bed and a downstream location. This vacuum condition can provide a force sufficient to cause target gas released during the releasing step described above to flow out of the electrochemical cell. The vacuum condition can be applied such that the pressure inside the electrochemical cell during or after the releasing of the target gas is less than or equal to 760 torr, less than or equal to 700 torr, less than or equal to 500 torr, less than or equal to 100 torr, less than or equal to 50 torr, less than or equal to 10 torr, and / or as low as 5 torr, as low as 1 torr, as low as 0.5 torr, as low as 0.1 torr.

[0109] In an aspect, the composite of the first electrode has a particular capacity for absorbing target gas (e.g., CO2). For example, the composite can have an absorption capacity of at least 0.01 mole per square meter (mol per m2), at least 0.02 mol per m2, at least 0.05 mol per m2, or more. In an aspect, the composite can have an absorption capacity of less than or equal to 0.2 mol per m2, less than or equal to 0.08 mol per m2, less than or equal to 0.05 mol per m2, less than or equal to 0.03 mol per m2, or less. For example, the composite can have an absorption capacity of at least 0.01 mol per m2and less than or equal to 0.2 mol per m2, or at least 0.02 mol per m2and less than or equal to 0.08 mol per m2.

[0110] In an aspect the composite of the first electrode can have a particular surface area that is exposed to the gas mixture, for example, of greater than or equal to 5 cm2, greater than or equal to 8 cm2, greater than or equal to 10 cm2, or up to 10 cm2, up to 20 cm2or more.

[0111] Various components of a system, such as the electrodes (e.g., negative electrode, positive electrodes), power source, electrolyte, separator, container, circuitry, insulating material, and the like can be fabricated by those of ordinary skill in the art from any of a variety of components. Components can be molded, machined, extruded, pressed, isopressed, printed, infiltrated, coated, in green or fired states, or formed by any other suitable technique.

[0112] The electrodes described herein (e.g., negative electrode, positive electrodes) can be of any suitable size or shape. Non-limiting examples of shapes include sheets, cubes, cylinders, hollow tubes, spheres, and the like. The electrodes may be of any suitable size, depending on the application for which they are used (e.g., separating gases from ventilated air, direct air capture, etc.). Additionally, the electrode can comprise a means to connect the electrode to another electrode, a power source, and / or another electrical device. Those of ordinary skill in the art are readily aware of techniques for forming components of system herein.

[0113] Various electrical components of system may be in electrical communication with at least one other electrical component by a means for connecting. A means for connecting can be any material that allows the flow of electricity to occur between a first component and a second component. A non-limiting example of a means for connecting two electrical components is a wire comprising a conductive material (e.g., copper, silver, etc.). In an aspect, the system can comprise electrical connectors between two or more components (e.g., a wire and an electrode). In an aspect, a wire, electrical connector, or other means for connecting can be selected such that the resistance of the material is low. In an aspect, the resistances can be substantially less than the resistance of the electrodes, electrolyte, or other components of the system.

[0114] Electrochemical cells and gas separation systems of the present disclosure can further be as described in U.S. Patent Application No. 16 / 659,398, the contents of which is incorporated by reference in its entirety for all purposes.

[0115] The electrochemical cells, systems, and methods described herein can be implemented in a variety of applications. The number of electrochemical cells or sets of cells can be scaled to the requirements of a particular application as needed. The following aspects provide several non-limiting examples of applications. In an aspect, the systems and methods described herein can be for removing a target gas (e.g., CO2) from ambient air, as well as enclosed spaces such as airtight building, car cabins - reducing the heating cost of incoming air for ventilation - and submarines and space capsules, where an increase in CO2 levels could be catastrophic. In aspects directed to the electrical power industry, they can be used for capturing carbon dioxide post- combustion at varying concentrations. In an aspect, the systems and methods are suitable for separate target gases from industrial flue gas or industrial process gas. Also, they can be used for capturing sulfur dioxide and other gases from flue gas. In aspects directed to the oil and gas industry, the disclosed systems and methods can be used for capturing carbon dioxide and other gases from various processes and diverting them for downstreamcompression or processing. The disclosed systems and methods can be applied to capture carbon dioxide from burning natural gas used to heat the greenhouses in mild and cold climates, then diverting the captured dioxide into the greenhouse for the plants to use in photosynthesis, i.e., to feed the plants.

[0116] In an aspect, a method for separating a target gas from a fluid mixture including the target gas can comprise contacting the fluid mixture with a quinone-containing polymer as disclosed herein. The target gas can be an electrophilic molecule as described herein (e.g., carbon dioxide). The quinone-containing polymer can be in a reduced state to form an anion adduct between the target gas the quinone-containing polymer in the reduced state.

[0117] This disclosure further encompasses the following aspects, which are nonlimiting.

[0118] Aspect 1 : A quinone-containing polymer comprising repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III), Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups; provided that when the quinone-containing polymer is a homopolymer according to Formula (I) and when Q is a single bond or -NR’-, X is -NH- or -S-.

[0119] Aspect 2: The quinone-containing polymer of aspect 1, wherein L is independently at each occurrence a single bond, a substituted or unsubstituted C1-6 alkylene group, a substituted or unsubstituted C6-30 arylene group, a substituted or unsubstituted C1-6 alkylene glycol group, or a combination thereof, preferably an unsubstituted phenylene group.

[0120] Aspect 3: The quinone-containing polymer of aspects 1 or 2, wherein A is an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a combination thereof.

[0121] Aspect 4: The quinone-containing polymer of any one of aspects 1 to 3, wherein the quinone-containing polymer further comprises repeating units different than the repeating units of Formulas (I) to (III).

[0122] Aspect 5: The quinone-containing polymer of aspect 4, wherein the repeating units different than the repeating units of Formulas (I) to (III) are derived from a diamine comonomer, a diol co-monomer, or dithiol co-monomer.

[0123] Aspect 6: The quinone-containing polymer of aspect 5, wherein the diamine comonomer is a substituted or unsubstituted aromatic diamine, the diol co-monomer is a substituted or unsubstituted aromatic diol, the dithiol co-monomer is a substituted or unsubstituted aromatic dithiol.

[0124] Aspect 7: The quinone-containing polymer of aspect 6, wherein the diamine comonomer, the diol co-monomer, or the dithiol co-monomer is substituted with a crosslinkable group.

[0125] Aspect 8: The quinone-containing polymer of aspect 7, wherein the crosslinkable group is one of an alpha-diazo ester group, a vinyl group, an azido group, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an isocyanato group, a halide, an aluminum salt, or a combination thereof.

[0126] Aspect 9: The quinone-containing polymer of aspect 4, wherein the repeating units different than the repeating units of Formulas (I) to (III) are present in an amount of 5 mole percent to 25 mole percent, based on total moles of all repeating units in the quinone-containing polymer.

[0127] Aspect 10: The quinone-containing polymer of any one of aspects 1 to 9, wherein the quinone-containing polymer comprises at least 5 repeating units according to at least one of Formulas (I)-(III), preferably at least 10 repeating units according to at least one of Formulas (I)- (III).

[0128] Aspect 11 : The quinone-containing polymer of any one of aspects 1 to 10, wherein at least 50 mole percent, or at least 75 mole percent, or at least 80 mole percent, or at least 90 mole percent, or at least 95 mole percent, or at least 99 mole percent of the repeating units are according to Formula (I), (II), or (III).

[0129] Aspect 12: The quinone-containing polymer of any one of aspects 1 to 11, wherein the quinone-containing polymer is a homopolymer consisting of repeating units according to Formula (I), (II), or (III).

[0130] Aspect 13: The quinone-containing polymer of any one of aspects 1 to 12, wherein the quinone-containing polymer has at least one reduced state with a binding constant with carbon dioxide of at least 101M’1, preferably I01to IO20M’1, more preferably I03to IO20M’1.

[0131] Aspect 14: The quinone-containing polymer of any one of aspects 1 to 13, wherein the quinone-containing polymer has a number average molecular weight of 1,000 to 200,000 grams per mole, or 2,500 to 200,000 grams per mole, or 5,000 to 200,000 grams per mole, or 10,000 to 200,000 grams per mole, or 10,000 to 100,000 grams per mole, or 10,000 to 75,000 grams per mole, or 20,000 to 50,000 grams per mole.

[0132] Aspect 15: The quinone-containing polymer of any one of aspects 1 to 14, wherein the repeating units are of at least one of Formulas (IV) to (XXII)wherein in Formulas (IV) to (XXII), R1to R9are independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a Ci- 30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group.

[0133] Aspect 16: The quinone-containing polymer of aspect 15, wherein the polymer comprises repeating units according to any of Formulas (IV)-(IX).

[0134] Aspect 17: The quinone-containing polymer of aspect 15, wherein the polymer comprises repeating units according to any of Formulas (X)-(XII).

[0135] Aspect 18: The quinone-containing polymer of aspect 15, wherein the polymer comprises repeating units according to any of Formulas (XIII)-(XXII).

[0136] Aspect 19: A method of making a quinone-containing polymer of aspects 1 to 18, the method comprising: polymerizing a dihydroxy naphthoquinone, a dihydroxy benzoquinone, a dihydroxy anthraquinone, a diamino naphthoquinone, a diamino benzoquinone, a diamino anthraquinone, a dithio benzoquinone, a dithio anthraquinone, a dithio naphthoquinone, or a combination thereof, with a diisocyanate under conditions effective to provide the quinone- containing polymer.

[0137] Aspect 20: The method of aspect 19, wherein the polymerizing is performed in the absence of a catalyst.

[0138] Aspect 21: The method of aspects 19 or 20, wherein the polymerizing is performed in a dry solvent.

[0139] Aspect 22: The method of aspect 21, wherein the dry solvent is a polar, aprotic solvent.

[0140] Aspect 23: The method of any of aspects 19 to 22, wherein the conditions effective to provide the quinone-containing polymer comprise a temperature of 20 to 100°C and a time of 1 minute to 24 hours, for example 1 to 5 hours, or 2 to 3 hours.

[0141] Aspect 24: A composite comprising a quinone-containing polymer disposed on a substrate, wherein the quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III), Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a C6-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.

[0142] Aspect 25: The composite of aspect 24, wherein the substrate comprises a carbonaceous material.

[0143] Aspect 26: The composite of aspect 24 or 25, wherein the quinone-containing polymer is at least partially crosslinked.

[0144] Aspect 27: An electrode assembly comprising: a porous separator; and the composite of any of aspects 24 to 26 on a surface of the porous separator, in a pore of the porous separator, or a combination thereof.

[0145] Aspect 28: An electrochemical cell comprising the composite of any of aspects 24 to 26.

[0146] Aspect 29: The electrochemical cell of aspect 28, comprising: a first electrode comprising the composite of any of aspects 24 to 26; a second electrode comprising a complementary electroactive layer; and a first separator between the first electrode and the second electrode.

[0147] Aspect 30: The electrochemical cell of aspects 28 or 29, wherein the electrochemical cell further comprises an electrolyte.

[0148] Aspect 31 : A gas separation system comprising a plurality of electrochemical cells in fluid communication with a gas inlet and a gas outlet, wherein each of the plurality of electrochemical cells is according to any of aspect 28 to 30.

[0149] Aspect 32: An energy storage device comprising the quinone-containing polymer of any of aspects 1 to 18, the composite of aspects 24 to 26, or the electrochemical cell of any of aspects 28 to 30.

[0150] Aspect 33: An electrochromic device comprising the quinone-containing polymer of any of aspects 1 to 18, the composite of any of aspects 24 to 26 or the electrochemical cell of any of aspects 28 to 30.

[0151] Aspect 34: A method for separating a target gas from a fluid mixture comprising the target gas, the method comprising: contacting the fluid mixture with a quinone-containing polymer, wherein the quinone-containing polymer is in a reduced state, to form an anion adduct between the target gas and the quinone-containing polymer in the reduced state; wherein the quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III) Q is independently at each occurrence a single bond, -O-, -S-, - NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-; L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof; X is independently at each occurrence -O-, -S-, or -NH-; A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, asubstituted or unsubstituted C1-20 alkylene group, or a combination thereof; and R is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.

[0152] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any materials (or species), steps, or components, that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0153] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and / or” unless clearly stated otherwise. Reference throughout the specification to “an aspect” means that a particular element described in connection with the aspect is included in at least one aspect described herein, and may or may not be present in other aspects. The term “combination thereof’ as used herein includes one or more of the listed elements, and is open, allowing the presence of one or more like elements not named. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various aspects.

[0154] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0155] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflictswith a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0156] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valency filled by a bond as indicated, or a hydrogen atom. A dashthat is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached through carbon of the carbonyl group.

[0157] As used herein, the term “hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when the hydrocarbyl residue is described as substituted, it may, optionally, contain heteroatoms over and above the carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, the hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, or the like, or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" means a branched or straight chain, saturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n- pentyl, s-pentyl, and n- and s-hexyl. “Alkenyl” means a straight or branched chain, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HOCH2)). “Alkoxy” means an alkyl group that is linked via an oxygen (i.e., alkyl-O-), for example methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" means a straight or branched chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH2-) or, propylene (- (CH2)3-)). “Cycloalkylene” means a divalent cyclic alkylene group, -CnH2n-x, wherein x is the number of hydrogens replaced by cyclization(s). “Cycloalkenyl” means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, wherein all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing the specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. “Arylene” means a divalent aryl group. “Alkylarylene” means an arylene group substituted with an alkyl group. “Arylalkylene” means an alkylene group substituted with an aryl group (e.g., benzyl). “Heteroarylene” means a divalent heteroaryl group. The prefix "halo" means a group or compound including one more of a fluoro, chloro, bromo, or iodo substituent. A combination of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix “hetero” means that the compound or group includes at leastone ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatom(s)), wherein the heteroatom(s) is each independently N, O, S, Si, or P. “Substituted” means that the compound or group is substituted with at least one (e.g., 1, 2, 3, or 4) substituents that can each independently be a C1-9 alkoxy, a C1-9 haloalkoxy, a nitro (-NO2), a cyano (-CN), a C1-6 alkyl sulfonyl (-S(=O)2-alkyl), a C6-12 aryl sulfonyl (-S(=O)2-aryl), a thiol (-SH), a thiocyano (-SCN), a tosyl (CH3C6H4SO2-), a C3-12 cycloalkyl, a C2-12 alkenyl, a C5-12 cycloalkenyl, a C6-12 aryl, a C7-13 arylalkylene, a C4-12 heterocycloalkyl, and a C3-12 heteroaryl instead of hydrogen, provided that the substituted atom’s normal valence is not exceeded. The number of carbon atoms indicated in a group is exclusive of any substituents. For example -CH2CH2CN is a C2 alkyl group substituted with a nitrile.

[0158] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

Claims

CLAIMS1. A quinone-containing polymer comprising repeating units of at least one ofFormulas (I) to (III):wherein in Formulas (I) to (III)Q is independently at each occurrence a single bond, -O-, -S-, -NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-;L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof;X is independently at each occurrence -O-, -S-, or -NH-;A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; andR is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups; provided that when the quinone-containing polymer is a homopolymer according to Formula (I) and when Q is a single bond or -NR’-, X is -NH- or -S-.

2. The quinone-containing polymer of claim 1 , wherein L is independently at each occurrence a single bond, a substituted or unsubstituted Ci-6 alkylene group, a substituted or unsubstituted Ce-30 arylene group, a substituted or unsubstituted Ci-6 alkylene glycol group, or a combination thereof, preferably an unsubstituted phenylene group.

3. The quinone-containing polymer of claim 1 , wherein A is an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a combination thereof.

4. The quinone-containing polymer of claim 1 , wherein the quinone-containing polymer further comprises repeating units different than the repeating units of Formulas (I) to (III), optionally wherein the repeating units different than the repeating units of Formulas (I) to (III) are derived from a diamine co-monomer, a diol co-monomer, or dithiol co-monomer.

5. The quinone-containing polymer of claim 4, wherein the diamine co-monomer is a substituted or unsubstituted aromatic diamine, the diol co-monomer is a substituted or unsubstituted aromatic diol, the dithiol co-monomer is a substituted or unsubstituted aromatic dithiol, optionally wherein the diamine co-monomer, the diol co-monomer, or the dithiol comonomer is substituted with a crosslinkable group.

6. The quinone-containing polymer of claim 5, wherein the crosslinkable group is an alphadiazo ester group, a vinyl group, an azido group, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an isocyanato group, a halide, an aluminum salt, or a combination thereof.

7. The quinone-containing polymer of claim 4, wherein the repeating units different than the repeating units of Formulas (I) to (III) are present in an amount of 5 mole percent to 25 mole percent, based on total moles of all repeating units in the quinone-containing polymer.

8. The quinone-containing polymer of claim 1 , wherein the quinone-containing polymer comprises at least 5 repeating units according to at least one of Formulas (I) to (III), preferably at least 10 repeating units according to at least one of Formulas (I) to (III).

9. The quinone-containing polymer of claim 1 , wherein at least 50 mole percent, or at least 75 mole percent, or at least 80 mole percent, or at least 90 mole percent, or at least 95 mole percent, or at least 99 mole percent of the repeating units are according to Formula (I), (II), or (III).

10. The quinone-containing polymer of claim 1, wherein the quinone-containing polymer is a homopolymer consisting of repeating units according to Formula (I), (II), or (III).

11. The quinone-containing polymer of claim 1 , wherein the quinone-containing polymer has at least one reduced state with a binding constant with carbon dioxide of at least 101M1, preferably 101to IO20M’1, more preferably 103to 102°M-1.

12. The quinone-containing polymer of claim 1 , wherein the quinone-containing polymer has a number average molecular weight of 1,000 to 200,000 grams per mole, or 2,500 to 200,000 grams per mole, or 5,000 to 200,000 grams per mole, or 10,000 to 200,000 grams per mole, or 10,000 to 100,000 grams per mole, or 10,000 to 75,000 grams per mole, or 20,000 to 50,000 grams per mole.

13. The quinone-containing polymer of claim 1 , wherein the repeating units are of at least one of Formulas (IV) to (XXII)wherein in Formulas (IV) to (XXII), R1to R9are independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group, a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a Ci-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group.

14. The quinone-containing polymer of claim 13, wherein the polymer comprises repeating units according to any of Formulas (IV) to (IX).

15. The quinone-containing polymer of claim 13, wherein the polymer comprises repeating units according to any of Formulas (X) to (XII).

16. The quinone-containing polymer of claim 13, wherein the polymer comprises repeating units according to any of Formulas (XIII) to (XXII).

17. A method of making a quinone-containing polymer of claim 1 , the method comprising: polymerizing a dihydroxy naphthoquinone, a dihydroxy benzoquinone, a dihydroxy anthraquinone, a diamino naphthoquinone, a diamino benzoquinone, a diamino anthraquinone, a dithio benzoquinone, a dithio anthraquinone, a dithio naphthoquinone, or a combination thereof, with a diisocyanate under conditions effective to provide the quinone-containing polymer.

18. The method of claim 17, wherein the polymerizing is performed in the absence of a catalyst; orthe polymerizing is performed in a dry solvent, preferably wherein the dry solvent is a polar, aprotic solvent.

19. The method of claim 17, wherein the conditions effective to provide the quinone- containing polymer comprise a temperature of 20 to 100°C and a time of 1 minute to 24 hours, for example 1 to 5 hours, or 2 to 3 hours.

20. A composite comprising a quinone-containing polymer disposed on a substrate, wherein the quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III)Q is independently at each occurrence a single bond, -O-, -S-, -NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-;L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof;X is independently at each occurrence -O-, -S-, or -NH-;A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; andR is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group;n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.

21. The composite of claim 20, wherein the substrate comprises a carbonaceous material.

22. The composite of claim 20, wherein the quinone-containing polymer is at least partially crosslinked.

23. An electrode assembly comprising: a porous separator; and the composite of claim 20 on a surface of the porous separator, in a pore of the porous separator, or a combination thereof.

24. An electrochemical cell comprising the composite of claim 20.

25. The electrochemical cell of claim 24, comprising: a first electrode comprising the composite of claim 20; a second electrode comprising a complementary electroactive layer; and a first separator between the first electrode and the second electrode.

26. The electrochemical cell of claim 25, wherein the electrochemical cell further comprises an electrolyte.

27. A gas separation system comprising a plurality of electrochemical cells in fluid communication with a gas inlet and a gas outlet, wherein each of the plurality of electrochemical cells is according to claim 25.

28. An energy storage device comprising the quinone-containing polymer of claim 1.

29. An electrochromic device comprising the quinone-containing polymer of claim 1.

30. A method for separating a target gas from a fluid mixture comprising the target gas, the method comprising:contacting the fluid mixture with a quinone-containing polymer, wherein the quinone- containing polymer is in a reduced state, to form an anion adduct between the target gas and the quinone-containing polymer in the reduced state; wherein the quinone-containing polymer comprises repeating units of at least one of Formulas (I) to (III):wherein in Formulas (I) to (III)Q is independently at each occurrence a single bond, -O-, -S-, -NR’- wherein R’ is hydrogen or a Ci-6 alkyl group, -(C=O)-, or -(C=O))NH-;L is independently at each occurrence a single bond, a Ce-24 arylene group, a C1-12 alkylene group, a C1-12 alkylene glycol group, or a combination thereof;X is independently at each occurrence -O-, -S-, or -NH-;A is independently at each occurrence a substituted or unsubstituted C6-20 arylene group, a substituted or unsubstituted C1-20 alkylene group, or a combination thereof; andR is independently at each occurrence hydrogen, halogen, a C1-30 alkyl group, a C1-30 alkoxy group, a poly(Ci-3o alkylene oxide) group; a C3-30 cycloalkyl group, a C3-30 branched alkyl group, a C6-30 aryl group, a C3-30 heteroaryl group, a C1-30 fluoroalkyl group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, a thiol group, or a vinyl group; n is 2 to 10; and the dashed lines of Formulas (II) and (III) indicate the presence of at least one or more additional fused substituted or unsubstituted aryl groups.