Boron-containing porous membrane and method of using the same

Abstract

To provide a boron-containing proton exchange membrane having high mechanical strength, high proton conductivity, low electron conductivity, chemical stability under a high pH gradient, durability, and low manufacturing cost, and to provide a manufacturing method of the proton exchange membrane, and a membrane electrode assembly.SOLUTION: The proton exchange membrane includes a porous structural framework and boron-based acidic groups bonded to the porous structural framework. The framework of the porous structure may be formed of amorphous or crystalline inorganic materials and / or synthetic or natural polymers. The boron-based acidic group may be a boric acid derivative such as a cyclic boric acid derivative, borosporanic acid, or a borosporanic acid derivative. The boron-based acidic group may be a reaction product of boric acid or a boric acid derivative with a polyhydroxy compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (Related Applications) This application is a continuation of U.S. Provisional Patent Application No. 63 / 109,943, filed September 5, 2020. Priority is claimed, the contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] Proton exchange membranes (PEMs) are impermeable to gases such as hydrogen (H2) and oxygen (O2). But proton (H + ) is a semipermeable membrane designed to transport. PEMs can be used in hydrogen fuel cells and water electrolysis systems under ambient conditions. It may consist of a porous framework that is mechanically and chemically resistant. Fion-based proton exchange membranes are made of polytetrafluoroethylene with sulfonic acid groups. The porous structure of the PTFE framework is easily dissociated, and the sulfonic acid groups are easily dissociated. It functions as a proton transport agent in Summary of the Invention

[0003] The following is a simplified version of one or more aspects of the methods and systems described herein. This summary provides a basic understanding of such aspects. It is not intended to be an extensive overview of all aspects, but rather to identify key or important elements of all aspects. It is not intended to be exhaustive or to delineate the scope of any or all embodiments. Its sole purpose is to serve as a prelude to the more detailed description that follows. To present some concepts of one or more aspects of the methods and systems described herein in a simplified form. is.

[0004] In some exemplary embodiments, the proton exchange membrane is a porous structure framework. and boron-based acidic groups attached to the framework of the porous structure.

[0005] In some exemplary embodiments, the boron-based acidic group is a cyclic boronic acid derivative. Including the body.

[0006] In some exemplary embodiments, the boron-based acidic group is borospiranil. Contains quasi-acid (borospiranic acid).

[0007] In some exemplary embodiments, the boron-based acidic group is a catechol-derived Including the body.

[0008] In some exemplary embodiments, the porous framework is a boron-based The solid support particles are linked by the acid groups of the base.

[0009] In some exemplary embodiments, the framework of the porous structure comprises a porous polymer. the boron-based acidic groups are present in the fine particles of the polymer network. It is bonded to the pore surface.

[0010] In some exemplary embodiments, the framework of the porous structure comprises an inorganic material. nothing.

[0011] In some exemplary embodiments, the method for making a proton exchange membrane comprises using a boron-based The acidic groups of the polymer are bonded to the pore surfaces of the porous framework. .

[0012] In some exemplary embodiments, the binding comprises bonding boric acid or a boric acid derivative to , which involves reacting with the hydroxyl groups present on the pore surfaces.

[0013] In some exemplary embodiments, the conjugating comprises combining the polyhydroxy compound with This involves reacting with boric acid derivatives that are bonded to the pore surfaces.

[0014] In some exemplary embodiments, the method comprises: It further comprises binding nanoparticles to the pore surface.

[0015] In some exemplary embodiments, the membrane electrode assembly includes a cathode, an anode, and the a cathode and a proton exchange membrane disposed between the anode, the proton exchange membrane , bound to the framework of the porous structure and to the pore surfaces in the framework of the porous structure. Contains boron-based acidic groups.

[0016] In some exemplary embodiments, at least one of the anode or cathode is and an ionomer for binding the catalyst, the ionomer being a boron-based Contains an acidic group. [Brief explanation of the drawings]

[0017] The accompanying drawings illustrate various embodiments and are a part of the specification. The embodiments are merely examples and are not intended to limit the scope of the present disclosure. The same or similar reference numbers indicate the same or similar elements. [Figure 1] FIG. 1 shows an exemplary proton exchange membrane that includes a porous framework and boron-based acidic groups attached to the pore surfaces of the porous framework. [Figure 2] Figure 2A shows an exemplary structure of the porous framework and boron-based acidic groups in the PEM of Figure 1. Figure 2B shows another exemplary structure of the porous framework and boron-based acidic groups in the PEM of Figure 1. [Figure 3] Figure 3A shows an exemplary reaction scheme for synthesizing a cyclic boronic acid derivative, and Figure 3B shows an exemplary reaction scheme for synthesizing a borospiranic acid. [Figure 4] Figure 4A shows an exemplary reaction scheme for synthesizing a solid support-bound monocyclic boronic acid derivative, and Figure 4B shows an exemplary reaction scheme for synthesizing a solid support-bound borospiranic acid with a pendant moiety. [Figure 5] Figure 5A shows an exemplary reaction scheme for synthesizing a solid support-bound cyclic boronic acid derivative incorporating a catechol derivative, and Figure 5B shows an exemplary reaction scheme for synthesizing a solid support-bound borospiranic acid incorporating a catechol derivative and a pendant moiety. [Figure 6] FIG. 6 shows an exemplary reaction scheme 600 for synthesizing a cross-linked copolymer containing boron-based acidic groups. [Figure 7] FIG. 7 shows an exemplary reaction scheme for functionalizing the pore surfaces of the framework of the porous structure with boric acid derivatives. [Figure 8] Figure 8A shows another exemplary reaction scheme for functionalizing the pore surface of the framework of a porous structure with a boric acid derivative, and Figure 8B shows another exemplary reaction scheme for functionalizing the pore surface of the framework of a porous structure with a boric acid derivative (borospiranic acid). [Figure 9] Figure 9A shows an exemplary reaction scheme for attaching particles (e.g., nanoparticles) to the pore surfaces of a porous framework using a boric acid derivative (e.g., borospiranic acid), and Figure 9B shows an exemplary reaction scheme for crosslinking multiple particles comprising multiple sheets within a polymer structure using a boric acid derivative. [Figure 10]FIG. 10 shows an exemplary proton exchange membrane water electrolysis system incorporating a boron-containing porous membrane. [Figure 11] FIG. 11 shows an exemplary proton exchange membrane fuel cell incorporating a boron-containing porous membrane. DETAILED DESCRIPTION OF THE INVENTION

[0018] Boron-containing porous films and methods of making and using the same are described herein. In some examples, the boron-containing porous film comprises a porous framework and a and boron-based acidic groups covalently bonded to the framework of the porous structure. The framework of the porous structure may be made of amorphous or crystalline inorganic materials and / or synthetic materials. The boron-based acidic groups may be formed from cyclic or natural polymers. Boric acid derivatives, borospiranic acid, In some examples, the hydroxybenzoate may be a boric acid derivative such as a borospiranic acid derivative. In the case of the present invention, the boron-based acidic group is a compound selected from the group consisting of boric acid or a boric acid derivative and a polyhydroxy compound. It is the reaction product of

[0019] The boron-containing porous membranes described herein are suitable for water electrolysis and / or fuel electrolysis operating under acidic conditions. The boron-containing PEMs described herein can be used as PEMs for battery applications. In this case, cation (e.g., proton) exchange occurs ionically with the tetravalent negatively charged boron atom. The presence of oxygen-boron bonds contributes to the formation of a porous structure. It improves the hydrophilicity of the membrane and stabilizes the negatively charged boron atoms. The boron-containing PEMs described have high mechanical strength, high proton conductivity, and low electronic conductivity. It has chemical stability and durability under high pH gradients, and is low in manufacturing cost. The membranes can be made from boric acid and its precursor (borax), which is naturally abundant and inexpensive. In addition, in some instances, the boron-containing porous membranes described herein can also be used to absorb toxic substances. Does not contain.

[0020] The boron-containing porous membranes described herein are effective in preventing pathogens such as bacteria, viruses, and fungal spores. They can also be used to filter and / or neutralize active ingredients. For example, boron-containing porous membranes can be used to , face masks, surgical masks, air filters, and confined spaces (e.g., homes, The present invention may also be incorporated into air purifiers for use in public buildings, hospitals, factories, vehicles, airplanes, etc.

[0021] The devices, compositions and methods described herein may provide one or more of the benefits and / or This may provide a variety of additional and / or alternative benefits that may be identified herein. Various embodiments will now be described in more detail with reference to the figures. The following embodiments are merely illustrative and not limiting, as various modifications may be made within the scope of the present invention. You will understand that.

[0022] FIG. 1 shows an exemplary proton exchange membrane 100 (PEM 100). The porous framework 102 and the entire porous framework 102 The boron-based acidic molecules are distributed in the porous structure and bonded to the pore surfaces of the porous framework 102. Contains group 104.

[0023] The porous framework 102 may be made of any suitable material, including inorganic and / or organic materials. The material may be formed of any suitable material or combination of materials. Suitable inorganic materials include amorphous inorganic materials (e.g., glass, quartz glass, or ceramics) and / or crystalline inorganic materials Suitable organic materials include: Examples of suitable polymers include synthetic and / or natural polymers (eg, cellulose).

[0024] The PEM 100 may have a thickness d ranging from a few microns to hundreds of microns. With the structure described in the document, the PEM100 can withstand a pressure difference of up to 30 atmospheres across the membrane and oxygen. The PEM100 may be permeable to water and protons. These may travel through PEM 100 as shown by arrow 106, but may not travel through PEM 101. 00 is generally impermeable to gases including hydrogen and oxygen.

[0025] The boron-based acidic groups 104 may be formed from two or more different 2A and 2B show the structure of the PEM 100. 1 shows an exemplary structure of the porous framework 102 and boron-based acidic groups 104. 2A and 2B each show only a portion of the PEM 100. It will be recognized as representative of the characteristics of the entire 100.

[0026] In the first exemplary structure 200A shown in FIG. 2A, the pore surface adjacent to the pore 204 The surface is boron-based such that the boron-based acidic groups 104 bond with the pore surfaces 202. 2A shows a single boron bonded to the pore surface 202. Although only the base acidic groups 104 are shown, the porous framework 102 may optionally include The number and concentration of boron-based acidic groups 104 attached to the pore surface 202 may be

[0027] In the second exemplary structure 200B shown in FIG. 2B, the framework of the porous structure 102 are solid support particles 206 (e.g., cellulose) linked together by boron-based acidic groups 104. For example, solid support particles 206-1 to 206-4). 6 forms pores 208 in the spaces between the solid support particles 206. The functional groups 104 are attached to the pore surfaces 210 (e.g., the pores of the solid support particles 206-1 to 206-4). 2B shows four solid support particles 206 are shown linked by a boron-based acidic group 104, but may be linked by any other number of solid support particles 206 may be linked by boron-based acidic groups 104 Additionally, each solid support particle 206 may contain one or more additional boron-based acid may be linked to one or more further solid support particles by groups, whereby Boron-based acidic groups 1 attached to the pore surfaces 210 of the framework 102 of the porous structure. A porous framework 102 having a porous structure 04 may be formed.

[0028] The solid support particles 206 may be any of the particles described above for the porous structural framework 102. Materials, such as inorganic molecules (e.g., quartz glass particles, ceramic particles, etc.) or organic molecules (e.g., The solid support particles 206 may be formed of any suitable material, such as a polymer. , and may be of any suitable shape and size ranging from tens of nanometers (nm) to hundreds of microns. The porosity of the PEM 100 is controlled and determined by the size of the solid support particles 206. In addition, the solid support particles 206 have mechanical strength and durability in an environment with a high pH gradient. and / or may be selected for their affinity for water (e.g., solid support particles may be selected for P Depending on the balance of water affinity required for EM100, hydrophilic or hydrophobic properties may be selected. ).

[0029] In some examples, the boron-based acidic group 104 is a boric acid derivative (e.g., a boric acid-derived Boric acid has the molecular formula B(OH)3 and is given by the formula (I): The following structure: [ka] It has.

[0030] Boric acid derivatives are produced by reacting one, two or all of the hydroxyl (OH) groups of boric acid. The boric acid derivative may be any compound or group that is linked to one or more other compounds. The conductors are described in more detail below.

[0031] The boric acid derivative may be formed by any suitable method. In some instances, boric acid derivatives may be formed by any suitable method. The acid derivatives are a mixture of boric acid or other boric acid derivatives and one or more other compounds. For example, boric acid or a boric acid derivative can be formed by reaction with two or more hydroxyl groups. The boric acid derivative can react with a polyhydroxy compound having cis-adjacent hydroxyl groups. Examples include, but are not limited to, cyclic boric acid derivatives, borospiranic acid, borosilicate, Any of the pyranic acid derivatives and any of the other boric acid derivatives described herein Suitable boric acid derivatives of the polyhydroxy compounds may include polyols, sugars, sugar alcohols (e.g., glycerol, mannitol, or sorbitol), catechol, or may be any suitable polyhydroxy compound, such as a derivative of any of these. In some examples, the polyhydroxy compound has the following formula (IIa) or (IIb): [ka] wherein W, X, Y, and Z are pendant moieties and each independently In other words, hydrogen (H), hydroxyl group (OH), fluoro group (F), chloro group (Cl), Dialkylamino group (NR2), cyano group (CN), carboxylic acid (COOH), carboxylic acid The group consisting of acid amides, carboxylic acid esters, alkyl groups, alkoxy groups, and aryl groups In some examples, any one or more of the groups W, X, Y, and Z can be selected from: Oxygen (O), hydroxyl group (OH), fluoro group (F), chloro group (Cl), dialkyl Amino group (NR2), cyano group (CN), carboxylic acid (COOH), carboxylic acid amide , carboxylic acid ester, alkyl group, alkoxy group, and aryl group, etc. C1-C, which may optionally contain groups 30 It may represent an alkyl chain.

[0032] Here, boric acid derivatives are produced by reacting boric acid or boric acid derivatives with polyhydroxy compounds. An exemplary reaction scheme for making the compound is shown and described with reference to Figures 3A and 3B. It will be appreciated that the reaction schemes are illustrative only and are not limiting.

[0033] FIG. 3A shows an exemplary reaction scheme 300A for synthesizing cyclic boronic acid derivatives. As shown, boric acid 302 binds with glycerol 304 to form a cyclic boric acid derivative. Glycerol 304 is represented by formula (IIa), where X, Y and Z are each hydrogen (H), and W is a hydroxymethyl group (CHOH). Figure 3A shows that boric acid reacts with glycerol 304, but boric acid 305 O2 may be any other suitable sugar (e.g., glucose, fructose, etc.), sugar alcohol (e.g., For example, mannitol, sorbitol, etc.) or polyhydroxy compounds. Alternatively or additionally, a boric acid derivative may be used in place of boric acid 302.

[0034] FIG. 3B shows an exemplary reaction scheme for synthesizing borospiranic acids, which are also boric acid derivatives. As shown, reaction scheme 300B is shown in FIG. The cyclic boronic acid derivative 306 produced by OA is bound to another glycerol molecule 304. Boric acid 302 is a weak acid, but sugar alcohols In the presence of polyhydroxy compounds such as chol (e.g., glycerol 304), 3B shows that the cyclic boronic acid derivative 306 is converted to a glycolic acid to form a borospiranic acid 308. The cyclic boronic acid derivative 306 is shown reacting with cerol 304. Other suitable sugars, sugar alcohols (e.g., mannitol, sorbitol, etc.) or polyhydroxys Additionally or alternatively, the cyclic boronic acid derivative 306 may react with any other may be replaced with a suitable cyclic boronic acid derivative of

[0035] Reaction schemes 300A and 300B shown in FIGS. 3A and 3B are 2A) and / or to generate boron-based acidic groups 104 bonded to the pores. used to generate boron-based acidic groups 104 attached to the surface 210 (see FIG. 2B) In some instances, the surface of the solid support material (e.g., the pore surface 202 or The particle surface 210 may be functionalized with boric acid derivatives or polyhydroxy compounds. In this case, the boron-based acidic groups 102 bonded to the pore surfaces of the porous framework 102 are An exemplary reaction scheme for forming 04 is shown and described with reference to Figures 4A-9B. It will be appreciated that the reaction schemes are merely illustrative and not limiting.

[0036] FIG. 4A shows an exemplary reaction scheme for synthesizing a solid support-bound monocyclic boronic acid derivative. As shown, solid support 402 is a cis-adjacent di-Hydroxylase (DHA)-like molecule. The solid support is functionalized with a cis-1,2-dihydroxy group 404 bearing a hydroxy group. The body 402 may be any of the inorganic materials described herein for the porous structural framework 102. on organic or organic solid support materials (e.g., glass, ceramic, synthetic polymers, natural polymers). The solid support may be formed with a polymerizable compound, and the polymerizable compound may have mechanical strength, durability in an environment with a high pH gradient, and / or may be selected for their affinity for water (e.g., as required for PEM100). (Hydrophilic or hydrophobic properties may be selected depending on the balance of water affinity between the solid support 40 and the substrate.) 2 may be particles similar to the solid support 206 described with reference to FIG. 2B. The solid support 402 is made of the porous framework 102 described with reference to FIG. 2A. It may be part of.

[0037] As shown in FIG. 4A, the cis-1,2-dihydroxy group 404 is represented by formula (IIa): and a linker chain 404 attached to a pendant moiety Y′ and a solid support 402. 6 (represented by the pendant group W or X in formula (IIa)). Linker chain 406 is C1~C 30 an alkyl chain, optionally identical to each atom of the linker chain 406; X' and Y' each have one or more pendant moieties X' which may be the same or different. Independently, hydrogen (H), hydroxyl group (OH), fluoro group (F), chloro group (Cl) ), dialkylamino group (NR2), cyano group (CN), carboxylic acid (COOH), The carboxylic acid amide, carboxylic acid ester, alkyl group, alkoxy group, and aryl group are The compound may be selected from the group consisting of:

[0038] The cis-1,2-dihydroxy group 404 reacts with boric acid 408 to form a solid support 402. This produces a monocyclic boronic acid derivative 410, which can be attached to a solid support. The cyclic boronic acid derivative 410 is a fine particle of the framework 102 of the porous structure of the PEM 100. Alternatively, the solid support may be provided with boron-based acidic groups 104 attached to the pore surface. The bound cyclic boronic acid derivative 410 is a polyhydroxybenzoate derivative, as described herein with reference to FIG. 4B. Further reaction with boric acid compounds gives other boric acid derivatives (e.g. borospiranic acid). It can be generated.

[0039] Figure 4B shows a borospiranic acid bound to a solid support with pendant moieties. 400B shows an exemplary reaction scheme for synthesizing a solid support. cyclic boronic acid derivative 410 (produced in reaction scheme 400A shown in FIG. 4A) bound to (i) is a polyhydroxy compound 412 having pendant moieties A', B', C', and D'; Polyhydroxy compound 412 has a structure represented by formula (IIa). Thus, the pendant moieties A', B', C' and D' are as defined above with respect to formula (IIa). The pendant moieties W, X, Y and Z may coincide.

[0040] The cyclic boronic acid derivative 410 and polyhydroxy compound 412 bound to the solid support are In response, borospirate bound to a solid support having pendant moieties A', B', C', and D' is This structure allows the formation of a borospiroic acid 414. Lanic Acid 414 is the pore surface of the framework 102 of the porous structure of PEM100. This can result in boron-based acidic groups 104 attached to the surface. Pyranic Acid 414 has the following electrical properties: A', B', C', D', X' and Y' substitutions Depending on the type, it may exhibit strong proton exchange properties.

[0041] In the example where the solid support 402 comprises a polymer network, boric acid bound to the solid support Derivative 410 and solid support-bound borospiranic acid 414 were prepared as follows: While controlling the loading amounts of uric acid and borospiranic acid, see Figures 10 and 11. To form an ionomer for the catalyst that is bonded to the catalyst layer in the membrane electrode assembly, as described below, It may also be used for

[0042] FIG. 5A shows a solid support-bound cyclic boronic acid derivative incorporating a catechol derivative. 5 shows an exemplary reaction scheme 500A for synthesizing the reaction In Scheme 500A, except that the polyhydroxy compound comprises a catechol derivative. , as in Reaction Scheme 400A.

[0043] In reaction scheme 500A, solid support 502 is functionalized with catechol derivative 504. The solid support 502 can be the same as or similar to the solid support 402. The aryl derivative 504 has a structure represented by formula (IIb), which comprises pendant moieties W″, Y″ and Z”, and a linker chain 506 (a pendant chain of formula (IIb)) attached to the solid support 502 The linker chain 506 includes a C1 to C 30 an alkyl chain, optionally , having one or more pendant moieties X″, which are linked together by a linker chain 5 The pendant moieties W", X", and Y" may be the same or different from each other. and Z" are each independently hydrogen (H), a hydroxyl group (OH), a fluoro group (F ), chloro group (Cl), dialkylamino group (NR2), cyano group (CN), carboxylic acid (COOH), carboxylic acid amide, carboxylic acid ester, alkyl group, alkoxy group, and and aryl groups.

[0044] The catechol derivative 504 was reacted with boric acid 508 to incorporate the catechol derivative. The solid support 502 is then bonded to a polymer to produce a cyclic boronic acid derivative 510. If the catechol is a catechol-formaldehyde resin, The chain structure may be introduced during polymerization as described below with reference to Figure 6. Alternatively, The catechol structure can be modified by post-polymerization (e.g., by functional modification of Merrifield-type resins). It may be introduced.

[0045] This structure allows the formation of a cyclic boron complex bound to a solid support incorporating a catechol derivative. The acid derivative 510 binds to the pore surface of the framework 102 of the porous structure of the PEM 100. Alternatively, the incorporation of catechol derivatives can result in the formation of boron-based acidic groups 104. The solid support-bound cyclic boronic acid derivative 510 containing the cyclic boronic acid derivative 510 is described herein with reference to FIG. 5B. It can be further reacted with polyhydroxy compounds to form other boric acid derivatives (e.g., borospiro). It is possible to produce benzoyl hydroxybenzoates (benzoyl hydroxybenzoates, ...

[0046] FIG. 5B shows a catechol derivative and a pendant moiety bound to a solid support. 5 shows an exemplary reaction scheme 500B for synthesizing a borospiranic acid derivative. In reaction scheme 500B, a solid support incorporating a catechol derivative is The bound cyclic boronic acid derivative 510 has pendant moieties A", B", C", and D". The polyhydroxy compound 512 is bound to a polyhydroxy compound 512 having the formula (IIa) Thus, the pendant moieties A", B", C", and D" have a structure represented by , which may correspond to the pendant moieties W, X, Y, and Z described above with respect to formula (IIa).

[0047] A solid support-bound cyclic boronic acid derivative 510 incorporating a catechol derivative is It is bound to polyhydroxy compound 512 and incorporates catechol derivatives, Solid support-bound borospiranic acid containing moieties A", B", C", and D". This structure incorporates a catechol derivative, producing 514. The solid support-bound borospiranic acid 514 containing the moiety was The porous structure has a framework 102 having boron-based acidic groups 104 bonded to the pore surfaces. This can result.

[0048] FIG. 6 shows an exemplary reaction scheme for synthesizing a crosslinked copolymer containing boron-based acidic groups. In reaction scheme 600, catechol 602, formaldehyde The aldehyde 604 and boric acid 606 combine and polymerize to form catechol-formaldehyde-boron. Copolymer 608 is a cross-linked copolymer of borosilicate and methylcellulose, resulting in a copolymer 608 ("copolymer 608"). Copolymer 6 includes catechol structures 610 linked by pyranic acid groups 612. The individual polymers of 08 are cross-linked by bridges 614 between the catechol structures 610. Copolymer 608 also contains phenol, resorcinol, and trihydroxyphenol. The copolymer may contain other phenolic monomers such as phenol.

[0049] Copolymer 608 is suitable for PEM and ionomer applications. For example, the copolymer 608 shown in FIG. 2B The structure of PEM100 is shown to be a boron-based acid group 104 (corresponding to boron-based acid group 104). The acid group 612 is bonded to the catechol structure 610 (corresponding to the solid support particle 206). The porous structure is formed by bonding and connecting the porous structure 10. 2. The mol% content of borospiranic acid groups 612 is shown in Figures 10 and 11. as a PEM 100 or as a catalyst layer in an MEA, as described below with reference to As an ionomer for catalysts, the ionomer content may be controlled for optimum functional properties.

[0050] As previously mentioned, in some instances, the pores within the porous framework 102 The surface (e.g., pore surface 202) is functionalized with boron-based acidic groups 104 (FIG. 2A 7-9A show that the pore surfaces of the porous framework are covered with boron-based acidic groups. These reaction schemes show exemplary reaction schemes for functionalizing the pore surface with It is compatible with solid support materials that have one or more hydroxyl groups. Examples of such materials include Examples include, but are not limited to, silica, glass, alumina, clay, synthetic polymers, and cellulose.

[0051] FIG. 7 illustrates an exemplary reaction scheme 700 for functionalizing pore surfaces with boron-based acidic groups. As shown in FIG. 7, solid support 702 has surface 704 and surface 706. 4. The surface 704 of the solid support 702 has a porous structure. the pore surfaces of the framework 102 (for example, the surface 202 shown in FIG. 2A), or the solid support The surface 210 of the solid support particle 206 shown in FIG. 2B may be a carrier particle. shows that the surface 704 has only one hydroxyl group 706, Surface 704 may have any other amount and concentration of hydroxyl groups 706. In scheme 700, the surface 704 of the solid support 702 is exposed to boric acid 708, The solid reacts with the hydroxyl group 706 to form a boric acid derivative 710 attached to the surface 704. The support-bound boric acid derivative 710 forms the framework of the porous structure of PEM100. Alternatively, the solid may have boron-based acidic groups 104 attached to the pore surfaces of the solid. The support-bound boric acid derivative 710 may be boric acid, other boric acid derivatives, or polyhydroxybenzoates. The compound may be further reacted to produce other boric acid derivatives.

[0052] Figure 8A shows the functionalization of the pore surface of the porous framework with boron-based acidic groups. Another exemplary reaction scheme 800A is shown. Reaction scheme 800A shows the reaction of boric acid 7 08 reacts with two hydroxyl groups 706 on the surface 704 to produce a cyclic boronic acid derivative 802. In some instances, the reaction is similar to reaction scheme 700, except that the reaction is carried out on surface 7 04 may be pre-activated to increase the surface density of hydroxyl groups 706. Any suitable preactivation process may be used. The cyclic boronic acid derivative 802 is The porous structure of the present invention is characterized in that the boron-based acidic groups 104 are bonded to the pore surfaces of the framework 102 of the porous structure. Alternatively, the cyclic boronic acid derivative 802 may be formed as described herein with reference to FIG. Thus, the boronic acid derivatives may be further reacted to form other boronic acid derivatives.

[0053] FIG. 8B shows a porous frame structure formed by a boric acid derivative (e.g., a borospiranic acid group). 8 shows another exemplary reaction scheme 800B for functionalizing the pore surfaces of a membrane. In Scheme 800B, the cyclic hydroxyl group produced in Reaction Scheme 800A shown in FIG. The carboxylic acid derivative 802 has pendant moieties A''', B''', C''', and D'''. The polyhydroxy compound 804 is a compound represented by the formula (IIa ) and thus the pendant moieties A''', B''', and C''' and D''' correspond to the pendant moieties W, X, Y, and Z described above with respect to formula (IIa). The cyclic boronic acid derivative 802 and the polyhydroxy compound 804 can react to form pendant. 806 and bonded to the pore surface 704. The solid support-bound borospiranic acid having pendant moieties 806 is The boron-based ions bonded to the pore surface of the framework 102 of the porous structure of PEM100. This may result in an acidic group 104.

[0054] FIG. 9A shows the formation of a porous structure by a boric acid derivative (e.g., borospiranic acid). Exemplary embodiments for attaching particles (e.g., nanoparticles or microparticles) to the pore surfaces of the framework include: Reaction scheme 900A is shown. The porosity of the PEM 100 is determined by the size of the particles 902. The particles 902 have mechanical strength, and can be controlled and determined in an environment with a high pH gradient. The solid support particles may be selected for their durability and / or affinity for water (e.g., solid support particles). The molecule can be selected to be hydrophilic or hydrophobic depending on the balance of water affinity required for PEM100. (This is also acceptable.)

[0055] Scheme 900A shows a particle 902 having a hydroxyl group 904 bonded to boric acid 708. As a result, the surface of the pore 704 is The hydroxyl groups 706 are reacted with the hydroxyl groups on the surface of the particles 902 using boric acid 708. The cross-coupling reaction is carried out by cross-linking the borospiranic acid 90 with the group 904. 6 provides a connection between the particles 902 and the pore surface 704. The particles 902 may be any suitable materials (e.g., silica, glass, alumina, ceramics, clays, synthetic polymers, cells The solid support 702 may be made of the same material as the solid support 702, or may be different.

[0056] Reaction Scheme 900A may be controlled to proceed in any order. The first step of Reaction Scheme 900A is to prepare a solid support-bound cyclic boronic acid derivative 8. In a second step, the reaction includes carrying out reaction scheme 800A to produce PO2. The molecule 902 is exposed to a cyclic boronic acid derivative 802 bound to a solid support, and the molecule is bound to the solid support. Alternatively, the first step can produce a borospiranic acid 906. In the example, particles 902 can combine with boric acid 708 to produce an intermediate boric acid derivative. In the second step, the hydroxyl groups 706 on the surface 704 of the solid support 702 are , exposed to an intermediate boric acid derivative and reacted to form a borospiranic acid bonded to the solid support. Acid 906 is generated to link particles 902 to solid support 702. In reaction scheme 900A, all reactants are combined in a single step. This can be done by:

[0057] FIG. 9B shows the use of boric acid derivatives to produce multiple particles containing multiple sheets within a polymer structure. 9 shows an exemplary reaction scheme 900B for crosslinking a In reaction scheme 900B, particles 902 (first particles 902) are Instead of being bridged by the hydroxyl group 706, two hydroxyl groups 910 are presented. Similar to reaction scheme 900A, except crosslinked with second particle 908. The first particle 902 and the second particle 908 are each microparticles or nanoparticles, and in certain implementations Any size (e.g., from a few nanometers to hundreds of microns) that can be suitable for Reaction Scheme 900B can be used to prepare a borospiranic acid group 914 The first particle 902 and the second particle 908 are connected by the same The material may be made of different materials or may be used in combination with the materials described herein. Any suitable solid support material (e.g., silica, glass, alumina, ceramic, clay, synthetic The polymer may be selected from the group consisting of synthetic polymers, cellulose, etc.

[0058] Reaction scheme 900B effectively uses the second structure 200B shown in FIG. 2B to The porosity of the PEM 100 can be determined by the first particles 90 2 and the size of the second particle 908.

[0059] The boron-containing porous membranes described herein can be used in water electrolysis and / or fuel cell applications. An exemplary application will now be described with reference to Figures 10 and 11.

[0060] FIG. 10 illustrates an exemplary proton exchange membrane water electrolysis system incorporating a boron-containing porous membrane. The PEM water electrolysis system 1000 is shown. 000 uses electricity to separate water into oxygen (O2) and hydrogen (H2) through an electrochemical reaction. The structure of the PEM water electrolysis system 1000, like any other suitable water electrolysis system, is as follows: These are merely exemplary and not limiting, as other suitable structures may incorporate the boron-containing porous membrane. It is not something that is done.

[0061] As shown in FIG. 10, the PEM water electrolysis system 1000 includes a membrane electrode assembly 1002 ( MEA 1002), porous transport layers 1004-1 and 1004-2, bipolar plate 1006 -1 and 1006-2, and a power supply source 1008. Also, the PEM water electrolysis system 1000 may include additional or alternative structures not shown in FIG. 10 as specific implementations may allow. It may also include a composition element.

[0062] The MEA 1002 is disposed between a first catalyst layer 1012-1 and a second catalyst layer 1012-2. The PEM 1010 contains a proton (H + ) and other cations While providing selective conductivity and preventing the permeation of gases such as hydrogen and oxygen, This electrically separates the first catalyst layer 1012-1 from the second catalyst layer 1012-2. The PEM 1010 can be any suitable PEM. For example, the PEM 1010 can be a porous Porous structures having boron-based acidic groups attached to the pore surfaces within the framework of the structure. The porous membrane may be a boron-containing membrane (eg, PEM100) that includes a framework of the structure.

[0063] The first catalyst layer 1012-1 and the second catalyst layer 1012-2 are made of platinum, ruthenium, and and / or a conductive electrode with an embedded electrochemical catalyst (not shown) such as cerium (IV) oxide. In some examples, the first catalyst layer 1012-1 and the second catalyst layer 101 2-2 is formed using an ionomer to bind catalyst nanoparticles. The catalyst layers used to form the first catalyst layer 1012-1 and the second catalyst layer 1012-2 are Ionomers, as described herein, include boron copolymers such as copolymer 608 (see FIG. 6). The base may contain acidic groups.

[0064] MEA 1002 is placed between porous transport layers 1004-1 and 1004-2. EA 1002 is similarly placed between bipolar plates 1006-1 and 1006-2, Flow channels 1014-1 and 1014-2 are formed between bipolar plate 1006 and porous transport layer 1004. Located between.

[0065] In the MEA 1002, the first catalyst layer 1012-1 functions as an anode, and the second catalyst layer 1012-2 functions as an anode. The catalyst layer 1012-2 functions as a cathode. When the electrodes are powered by a power supply 1008, the acid is represented by the following electrochemical half reaction: An elementary evolution reaction (OER) occurs at anode 1012-1. 2H2O→O2+4H + +4e - Protons pass through the PEM 1010 from the anode 1012-1 to the cathode 1012-2 The electrons are then conducted from the anode 1012-1 to the cathode 1012-2 by a conduction path around the PEM 100. The PEM 1010 conducts electricity from the anode 1012-1 to the cathode 1012-2. Proton (H + ) and water, but not oxygen or hydrogen. At the cathode 1012-2, protons are released into the hydrogen atmosphere via the following electrochemical half-reaction: It combines with electrons in the bioreaction (HER). 4H + +4e - →2H2

[0066] OER and HER are two complementary electrochemical reactions that split water using electricity. This is represented by the overall water electrolysis reaction below: 2H2O → 2H2 + O2

[0067] FIG. 11 illustrates an exemplary proton exchange membrane fuel cell 1100 (P The PEM fuel cell 1100 is a PEM fuel cell that generates electricity as a result of an electrochemical reaction. In this example, the electrochemical reaction is hydrogen gas (H2) and oxygen gas (O2). Other suitable proton exchange membrane fuels include reacting oxygen (O2) with water to produce water and electricity. Similar to fuel cells, other suitable structures may incorporate boron-containing porous membranes, thus The structure of the M fuel cell 1100 is merely exemplary and not limiting.

[0068] As shown in FIG. 11, a PEM fuel cell 1100 includes a membrane electrode assembly 1102 (MEA 1102), porous transport layers 1104-1 and 1104-2, bipolar plates 1106-1 and The electric device 1108 is electrically connected to the MEA 1102 and has a P The PEM fuel cell 1100 is also powered by a PEM fuel cell 1100. 11. Additional or alternative components not shown in FIG. 11 may be included to provide .

[0069] The MEA 1102 is disposed between a first catalyst layer 1112-1 and a second catalyst layer 1112-2. The PEM 1110 is a proton (H + ) and other cations While providing selective conduction and preventing the permeation of gases such as hydrogen and oxygen, , electrically separating the first catalyst layer 1112-1 from the second catalyst layer 1112-2. EM 1100 may be provided by any suitable PEM. For example, PEM 1110 has boron-based acidic groups attached to the pore surfaces of the porous framework, The porous structure is provided by a boron-containing porous membrane (e.g., PEM100) containing a framework. can be obtained.

[0070] The first catalyst layer 1112-1 and the second catalyst layer 1112-2 are embedded electrochemical catalysts. In some examples, the first catalyst layer 1112-1 is a conductive electrode having a first catalyst layer 1112-1 (not shown). and the second catalyst layer 1112-2 is formed using an ionomer that binds catalyst nanoparticles. In some examples, the first catalyst layer 1112-1 and the second catalyst layer 1104 The ionomers used to form -2 are those described herein, such as copolymer 608 (see FIG. 6). These include ionomers incorporating boric acid derivatives as described above.

[0071] MEA 1102 is placed between porous transport layers 1104-1 and 1104-2, resulting in The flow path 1114 is located between the bipolar plates 1106-1 and 1106-2. In the MEA 1102, the first catalyst layer 1112-1 is located between the cathode and the cathode. The first catalyst layer 1112-1 functions as the cathode, and the second catalyst layer 1112-2 functions as the anode. The anode 1112-1 and the anode 1112-2 are electrically connected to the device 1108. Electricity is generated by a PEM fuel cell 1100 that drives the

[0072] During operation of the PEM fuel cell 1100, hydrogen gas (H2) is Oxygen gas (O 2 ) flows into the cathode side of the PEM fuel cell 1100. At the anode 1112-2, the hydrogen molecules undergo the following hydrogen oxidation reaction (HOR): Therefore, the catalyst generates protons (H + ) and electrons (e - ) 2H2→4H + +4e - Protons pass through the PEM 1100 and travel from the anode 1112-2 to the cathode 1112- 1, the electrons travel through the conduction path and device 1108 to the annulus around the PEM 1110. The electrons are conducted from the cathode 1112-2 to the cathode 1112-1. The protons and electrons combine with oxygen gas according to the oxygen reduction reaction (ORR): O2+4H + +4e - →2H2O Therefore, the overall electrochemical reaction in the PEM fuel cell 1100 is: 2H2+O2→2H2O is.

[0073] In the overall reaction, the PEM fuel cell 1100 produces water at the cathode 1112-1. Water flows through the PEM 1110 from the cathode 1112-1 to the anode 1112-2. and removed through outlets on the cathode and / or anode sides of the PEM fuel cell 1100. The overall reaction generates electrons at the anode that power the device 1108. .

[0074] The boron-containing porous membranes described herein (e.g., PEM100) are pathogen-neutralizing porous membranes. For example, the porous framework 102 may be used as a membrane to trap bacteria, fungi, etc. It may have pores small enough to prevent the transfer of pathogens such as spores and viruses. The boron-based acidic groups 104 are effective against bacteria, fungi, and viruses, including SARS-CoV-2. For example, they may have anti-pathogenic activity against pathogens, including SARS-CoV-2. The basic protein sites of the body can ionically bind to the acidic boron sites of the proton exchange membrane. This may prevent the migration of pathogens through the proton exchange membrane. Therefore, proton exchange membranes are suitable for use in face masks, surgical masks, and in enclosed spaces (e.g., It is used in air filters and air purifiers for homes, offices, hospitals, factories, vehicles, aircraft, etc. It can be equipped.

[0075] In the foregoing description, various exemplary embodiments have been described with reference to the accompanying figures. However, various modifications and variations may be made without departing from the scope of the following claims. It will be apparent that further embodiments may be implemented. Certain features of one embodiment described above may be combined with features of other embodiments described herein. The present specification and drawings are therefore to be construed as limiting. It should be regarded as illustrative, not semantic.

[0076] In the foregoing description, various exemplary embodiments have been described with reference to the accompanying figures. However, various modifications may be made without departing from the scope of the invention as set forth in the following claims. It will be apparent that modifications and variations can be made and further embodiments can be implemented. For example, certain features of one embodiment described herein may be combined with other embodiments described herein. The features of the embodiments may be combined or substituted. The drawings are to be regarded in an illustrative rather than a restrictive sense.

Claims

1. A porous framework; and boron-based acidic groups attached to the framework of the porous structure. ton exchange membrane.

2. 10. The proton exchanger of claim 1, wherein the boron-based acidic group comprises a cyclic boronic acid derivative. Membrane exchange.

3. 10. The process of claim 1, wherein the boron-based acidic group comprises a borospiranic acid. Proton exchange membrane.

4. The proton exchanger of claim 1 , wherein the boron-based acidic group comprises a catechol derivative. Membrane exchange.

5. The porous framework is made of solids linked by the boron-based acidic groups. The proton exchange membrane of claim 1 comprising solid support particles.

6. the porous structural framework comprises a porous polymer network; the boron-based acidic groups are attached to the pore surfaces of the polymer network; The proton exchange membrane of claim 1 .

7. 10. The proton exchange membrane of claim 1, wherein the porous framework comprises an inorganic material. film.

8. The boron-based acidic groups are bonded to the pore surfaces of the porous framework.

1. A method for making a proton exchange membrane, comprising:

9. The method of claim 8 , wherein the boron-based acidic group comprises a cyclic boric acid derivative.

10. The method of claim 8, wherein the boron-based acidic group comprises a borospiranic acid. Law.

11. The method of claim 8 , wherein the boron-based acidic group comprises a catechol derivative.

12. The bonding is performed by bonding boric acid or a boric acid derivative to the hydroxyl groups present on the pore surface.

9. The method of claim 8, comprising reacting with a sil group.

13. The bonding may comprise bonding a polyhydroxy compound to a boric acid-derived polymer bonded to the pore surface.

9. The method of claim 8, comprising reacting with the body.

14. and further binding nanoparticles to the pore surfaces by the boron-based acidic groups. The method of claim 8, comprising:

15. a cathode; an anode; a proton exchange membrane disposed between the cathode and the anode; The proton exchange membrane has a porous framework and a porous structure. and boron-based acidic groups attached to the surfaces of the pores in the porous membrane.

16. 16. The membrane electrode contact of claim 15, wherein the boron-based acidic group comprises a cyclic boric acid derivative. Merge.

17. 16. The method of claim 15, wherein the boron-based acidic group comprises a borospiranic acid. Membrane electrode assembly.

18. 16. The membrane electrode junction of claim 15, wherein the boron-based acidic group comprises a catechol derivative. Merge.

19. 16. The membrane electrode junction of claim 15, wherein the porous structural framework comprises an inorganic material. body.

20. At least one of the anode or the cathode has a catalyst and a bonding material for bonding the catalyst. Contains ionomers, 16. The membrane electrode assembly of claim 15, wherein the ionomer comprises boron-based acidic groups. 。

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