A chemically grafted reinforced double-through anion exchange composite membrane, its preparation method and application

Abstract

This invention discloses a chemically grafted reinforced double-penetrating anion exchange composite membrane, its preparation method, and its applications. The composite membrane comprises a continuous porous support material layer and an anion exchange electrolyte material continuously filled within its pores. The support material is a rigid polymer mesh with an aromatic structure, and the electrolyte material is a rigid aromatic anion exchange polymer. The two are bonded together through chemical grafting and π-π interactions. During preparation, the surface of the support material is first functionalized, and then the electrolyte material is deposited onto the support material via ultrasonic spraying, followed by heating to form chemical bonds. This composite membrane significantly improves mechanical strength and alkaline stability while maintaining or even increasing ionic conductivity, making it suitable for applications such as anion exchange membrane water electrolysis for hydrogen production, fuel cells, flow batteries, and carbon dioxide electroreduction.

Description

Technical Field

[0001] This invention belongs to the field of anion exchange membrane technology, specifically relating to a chemically grafted and enhanced double-through anion exchange composite membrane, its preparation method, and its application. Background Technology

[0002] Electrolyte materials are selectively permeable polymeric materials. Due to their functions of closing circuits, isolating products, and blocking electronic pathways, they are widely used in the field of electrochemistry, specifically in applications such as water electrolysis for hydrogen production, battery separators, flow batteries, and carbon dioxide electroreduction. Currently, the mainstream water electrolysis hydrogen production technologies are ALK (alkaline water electrolysis) using porous non-ionic (polyphenylene sulfide, PPS) membranes, or PEM (proton exchange membrane) using homogeneous proton exchange membrane (PEM) materials. The dense polymer structure of PEM has been widely recognized in the industry for its improved safety and efficiency in electrolysis equipment. However, the PEM water electrolysis technology requires acid-resistant precious metal catalysts, making this oxygen production technology, which originated from NASA, prohibitively expensive. In recent years, anion exchange membrane water electrolysis (AEMWE) has been considered an ideal solution for reducing the cost of hydrogen production. Its core material, the anion exchange membrane (AEM), needs to possess high ionic conductivity, good mechanical strength, and excellent alkali stability. However, commonly used anion exchange membrane materials (such as polyphenylene ether-based and polyarylpiperidin-based materials) generally suffer from low mechanical strength, high swelling ratio, and insufficient long-term operational stability, making it difficult to meet the requirements of industrial water electrolysis for membrane material lifespan and reliability.

[0003] Adding a porous support layer to ion exchange membranes is a common strategy to improve their mechanical strength. Early research attempted to introduce polytetrafluoroethylene (PTFE)-like support materials into proton exchange membranes (as reported by companies like Gore and DuPont), and this method has also been adopted for anion exchange membranes. However, current technologies still have two prominent problems:

[0004] Firstly, adding a support layer often comes at the cost of sacrificing ionic conductivity. For example, studies have reported that in composite membranes supported by polybenzimidazole (PBI) nanofibers, the loss of ionic conductivity can reach 10%–20%, with the highest conductivity being less than 0.08 S / cm. Quaternized polyphenylene oxide (QPPO) membranes reinforced with PTFE can increase mechanical strength from 20 MPa to 32 MPa, but the ionic conductivity drops sharply from 100 mS / cm to 10 mS / cm. Other examples, such as polyarylene piperidine membranes supported by porous polyethylene (PE), show a 30% increase in mechanical strength but a loss of over 50% in ionic conductivity. Sustainion, a mainstream product in the industry, has also been observed to experience a 10%–30% conductivity loss after composite formation.

[0005] Secondly, fluorinated support materials, such as PTFE, have poor compatibility and weak physical bonding with the hydrocarbon backbone (CH groups) commonly used in anion exchange membranes. This leads to delamination and detachment during long-term operation, causing safety issues. Furthermore, current literature lacks sufficient data on the long-term stability of composite anion exchange membranes under real electrolysis conditions, indicating a significant gap before commercial application.

[0006] Therefore, there is an urgent need to develop a new type of anion exchange composite membrane material that can significantly improve mechanical strength and stability without sacrificing ionic conductivity, while ensuring a strong bond and long-term compatibility between the support layer and the electrolyte material, thereby promoting the large-scale application of AEMWE technology. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a chemically grafted and reinforced double-through anion exchange composite membrane, its preparation method, and its applications. Through the selection and improvement of electrolyte materials, composite materials, and preparation processes, a significant leap in ionic conductivity, mechanical strength, and stability is achieved. The use of ionic electrolyte materials with high ionic conductivity and a rigid structure ensures the water electrolysis performance, mechanical strength, and stability of the prepared membrane material.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a chemically grafted and reinforced dual-penetration anion exchange composite membrane, comprising:

[0010] A continuous porous support material layer, wherein the porous support material is a rigid polymer material with an aromatic structure and a pore size range of 1-1000 μm;

[0011] A continuous anion exchange material, wherein the anion exchange material fills the pores of the porous support material layer;

[0012] The surface of the porous support material has functional groups, and the support material and the anion exchange material are grafted together through chemical bonds formed by the functional groups.

[0013] Preferably, the functional group is selected from at least one of Cl, Br, or carbon-carbon double bonds.

[0014] Preferably, the porous support material is selected from one or more of the following polymers:

[0015] Polystyrene (PS), styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene terpolymer (ABS), acrylonitrile-styrene-acrylate copolymer (ASA), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), styrene-methyl methacrylate copolymer (SMMA), syndiotactic polystyrene (Syndiotactic polystyrene) PS, sPS), polyethylene terephthalate (PET), modified polyethylene terephthalate (PETG), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), polyethylene naphthalate (PEN), polyarylate (RAR), polysulfone (PSU), polyethersulfone (PES), polyphenylene sulfone (PPSU), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), polyphenylene sulfide (PPS), high-temperature nylon (Polyphthalamide, PA), poly(m-xylenedimethylhexamethylene) (MXD6), sulfonated polyetheretherketone (SPEEK), sulfonated polyethersulfone (SPES), sulfonated polyphenylene sulfone (SPSU), polystyrene sulfonic acid (PSSA) and its salts, polybenzimidazole (PBI), polypropylene (PP), polyethylene (PE), tetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), cellulose acetate (CA).

[0016] Preferably, the porous support material layer is a woven mesh structure, which is obtained by mixing and melting the porous support material to prepare fine filaments and then weaving them; the porosity of the porous support material layer is above 40%, and the thickness ranges from 5 to 100 μm.

[0017] Preferably, the anion exchange material is selected from one or more compounds of the general formula (I):

[0018]

[0019] (I)

[0020] Where n and m are the number of repeating units; n is an integer from 1 to 2000; m is an integer from 1 to 2000;

[0021] Ar1 and Ar2 are each independently selected from the following structural segments:

[0022] , ,

[0023]

[0024] The values ​​of x1 and x2 range from 0 to 10;

[0025] LK1 and LK2 are linking groups, each independently selected from... or ;

[0026] EWG is selected from one of the following structural segments:

[0027] ;

[0028] R1 is the active group used in the crosslinking reaction, selected from one of the following structural segments:

[0029]

[0030] R2 is an ionic group or the same as the crosslinking group R1. If it is an ionic group, the cationic group is selected from one of the following structural segments:

[0031]

[0032] The anionic group is selected from one of the following structural segments:

[0033]

[0034] As a preferred choice, Ar1 is selected from or .

[0035] As a preferred option, R1 is selected from... or .

[0036] Secondly, the present invention provides a method for preparing the above-mentioned chemically grafted and enhanced double-penetrating anion exchange composite membrane, comprising the following steps:

[0037] Functionalization treatment is applied to porous support materials to introduce functional groups selected from Cl, Br, or carbon-carbon double bonds onto their surface;

[0038] Anion exchange material is dissolved in a polar aprotic solvent and diluted with a low-boiling-point organic solvent to prepare a spraying solution.

[0039] The ultrasonic spraying process is used to load the spraying solution onto both sides of the porous support material, and the thickness is adjusted by controlling the number of spraying cycles.

[0040] The porous support material is subjected to a heating and drying process, which allows the functional groups on the surface of the porous support material to form chemical bonds with the anion exchange material, thereby obtaining the chemically grafted and reinforced double-penetrating anion exchange composite membrane.

[0041] Preferably, the mass fraction of the spraying solution is 0.1-1%.

[0042] Preferably, the polar aprotic solvent is selected from one or more of DMF, NMP, and DMSO; and the low-boiling-point organic solvent is selected from one or more of IPA, EtOH, MeOH, THF, and EtOAc.

[0043] Preferably, the heating and drying temperature is 50-100℃.

[0044] Preferably, the thickness of the chemically grafted reinforced double-through anion exchange composite membrane is 45-200 μm.

[0045] Thirdly, the present invention provides the application of the above-mentioned chemically grafted and enhanced double-penetrating anion exchange composite membrane in scenarios such as hydrogen production by water electrolysis, fuel cells, flow batteries, carbon dioxide electroreduction, or water treatment.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] This invention significantly improves the mechanical strength of anion exchange composite membranes. By using a polymer mesh with a rigid aromatic structure as the support material and employing chemical grafting to form a strong covalent bond between the support layer and the electrolyte material, and by enhancing interfacial compatibility through the π-π interaction between the aromatic rings of the two materials, the tensile strength of the composite membrane is several times higher than that of a homogeneous membrane without support, and it is also significantly stronger than that of a support membrane that is only physically composited without grafting. This invention can meet the requirements of harsh operating conditions such as high-voltage electrolysis for the mechanical properties of membrane materials, and also plays an important role in reducing swelling and enhancing dimensional stability and alkaline stability.

[0048] Furthermore, this invention improves mechanical strength while avoiding the loss of ionic conductivity. Unlike existing technologies that often sacrifice ionic conductivity for increased strength, this invention provides a continuous channel for ion transport by rationally designing the porosity, pore size, and braided structure of the supporting material and introducing a micron-level phase separation structure. Simultaneously, chemical grafting does not hinder the ion conduction function of the electrolyte material; on the contrary, the tight interfacial bonding and suppressed swelling help maintain high conductivity. Experimental data show that the conductivity of the grafted composite membrane is comparable to or even slightly higher than that of homogeneous membranes, and far superior to that of ungrafted physical composite membranes and other types of thin-film composite materials.

[0049] The composite membrane provided by this invention exhibits excellent long-term operational reliability under anion exchange membrane electrolysis for hydrogen production. The integrated structure constructed through chemical grafting avoids the peeling or detachment of the support layer and membrane layer during operation. The electrochemical performance decay is extremely low during long-term continuous testing. It combines mechanical stability, electrolysis performance, and electrochemical stability, providing a competitive membrane material solution for the large-scale application of anion exchange membrane electrolysis technology. Attached Figure Description

[0050] Figure 1 In the diagram, A is a conceptual diagram of the material of this invention, and B is a side-section microscope image of the material sample and a schematic diagram of the grafting principle.

[0051] Figure 2 This is a schematic diagram of the process of the present invention.

[0052] Figure 3 Images of the membrane samples obtained in Examples 1-6 and Comparative Examples 1-6 are shown, where A is a photograph showing light transmission and B is a microscopic image of a side section.

[0053] Figure 4 This is a comparison chart of the mass loss of Examples 1-6 and Control Examples 1-6 after 30 days of accelerated degradation under pH=14 and 80℃ conditions.

[0054] Figure 5 The graph shows a comparison of the ionic conductivity and tensile strength of Examples 1-6 and Comparative Examples 1-6; where A is the penetrating ionic conductivity at 60°C, B is the penetrating ionic conductivity at 80°C, and C is the tensile strength.

[0055] Figure 6 The diagram shows the principle of the electrochemical testing device and the results of long-term stability testing. A is a schematic diagram of the test cell structure, B is the electrode connection method, C is the temperature control and data acquisition system, and D is the long-term operating voltage-time curve of Example 1 and Control Example 6 (homogeneous membrane) under the same electrolysis conditions. The horizontal axis is time (hours) and the vertical axis is voltage (V). Detailed Implementation

[0056] To make the technical solution of the present invention clearer and more complete, the present invention will be further described in detail below with reference to specific embodiments. Unless otherwise specified, the raw materials, reagents, and instruments used in the following embodiments can be purchased commercially. Experimental methods without specific conditions are generally performed according to conventional conditions in the art or according to the conditions recommended by the supplier.

[0057] The polyphenylene sulfide (PPS) used below is manufactured by Toray Industries, Inc. of Japan, model A310MN7; polystyrene (PS) is manufactured by China Petroleum & Chemical Corporation Guangzhou Branch, model GH660; polyetheretherketone (PEEK) is manufactured by Jilin Zhongyan Polymer Materials Co., Ltd., model 330UPF; and polyethyleneimine (PEI) is manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd., model E107078.

[0058] In this embodiment of the invention, the anion exchange materials used are selected from G1-G4, and their structural formulas are shown below:

[0059]

[0060] The synthesis method of G1 is as follows:

[0061]

[0062] 1,1'-Binaphthyl (9.9 g, 39 mmol) and 8-bromo-1,1,1-trifluoro-2-octanone (10.4 g, 40 mmol) were placed in a two-necked round-bottom flask, and dichloromethane (100 mL) was added; the mixture was mechanically stirred at room temperature to dissolve. The reaction system was cooled to 0 °C, and a trifluoromethanesulfonic acid / trifluoroacetic acid mixture (1:1, 20 g) was slowly added dropwise. After the addition was complete, the mixture was stirred at 0 °C for 10 min, and then the reaction system was transferred to a 30 °C water bath.

[0063] After the system temperature reached 30℃, the molecular weight increase was detected by gel permeation chromatography every half hour. When the average molecular weight reached 421 kDa, the reaction solution was poured into 1000 mL of cold 1:1 methanol / water solution, and a solid precipitated. The solid was collected and washed with deionized water. The solid was then collected, washed three times with ethanol, and redissolved in 160 mL of tetrahydrofuran. 40 wt% dimethylamine aqueous solution (18 g, 400 mmol) was added, and the reaction was stirred for 48 hours. A solid precipitated in anhydrous diethyl ether at 0℃ was then dried, and the product was crushed into a light brown powder, which is the G1 reaction intermediate. 1 H NMR (500 MHz, CDCl3, δ,ppm): 8.0-8.1 (m,2H), 7.6-8.0 (m, 8H), 7.2-7.3 (m, 2H), 2.4 (m, 2H), 2.0 (m, 2H), 1-1.7 (m,8H).

[0064] G1 reaction intermediate (10 g, 1 equiv.) was dissolved in 100 mL of tetrahydrofuran / methanol (1:1) solution to obtain the intermediate solution. 4,4'-(dimethyl-1,4-azadiyl)bis(N-(4-bromobutyl)-N,N-dimethylbutane-1-ammonium) (73.4 g, 5 equiv.) was dissolved in 600 mL of a tetrahydrofuran / methanol mixture (1:1). The intermediate solution was added to this mixture at 60 °C, and the reaction was continued for 2 days. The reaction system was then cooled to 30 °C, and 40 wt% trimethylamine aqueous solution (26 g, 20 equiv.) was added. The reaction was continued with stirring for another 2 days.

[0065] The concentrated reaction solution was added to a dialysis bag (permeable to molecules up to 50K) and washed with deionized water until the ionic conductivity of the washing solution was the same as that of deionized water. The solution was dried and ground to obtain 27.5g of a light brown powder, which is G1, with a yield of 97.7%. 1 ¹H NMR (500 MHz, DMSO-d⁶, δ, ppm): 7.6–8.2 (m, 10H), 7.2–7.3 (m, 2H), 2.8–3.4 (m, 41.8H), 2.4 (m, 2H), 1.2–2.0 (m, 22.5H). n:m = 800:177 was determined by NMR integration.

[0066] The synthesis method of G2 is as follows:

[0067]

[0068] Add 1,1'-binaphthyl (2.5 g, 9.75 mmol) and 6-bromo-1,1,1-trifluoro-2-heptanone (2.46 g, 10 mmol) to a two-necked reaction flask A, and dissolve in 25 mL of dichloromethane with mechanical stirring at room temperature. Cool the reaction system to 0°C, and slowly add a trifluoromethanesulfonic acid / trifluoroacetic acid mixture (1:1, 18 g). After the addition is complete, stir at 0°C for 10 min, and then transfer the reaction system to a 30°C water bath.

[0069] In a two-necked reaction flask B, 9,9-dimethylfluorene (17.05 g, 5.68 mmol) and 6-bromo-1,1,1-trifluoro-2-hexanone (7.4 g, 30.0 mmol) were dissolved in 170 mL of dichloromethane. After the temperature of the reaction system in flask A reached 30 °C, the molecular weight increase was monitored by gel permeation chromatography every half hour. When the average molecular weight reached 10 kDa, the solution from reaction flask B was added to reaction system A, and the reaction continued until the molecular weight of the product reached 210 kDa. The reaction solution was then poured into 2000 mL of cold 1:1 methanol / water solution, precipitating a solid. The solid was collected, washed three times with ethanol, dried, and crushed to obtain 15.1 g of a light brown powder, which was the intermediate of reaction G2, with a yield of 96.2%. 1 ¹H NMR (500 MHz, CDCl₃, δ, ppm): 8.0–8.1 (m, 8H), 7.6–8.0 (m, 14H), 7.3–7.4 (m, 6H), 7.2–7.3 (m, 2H), 2.4 (m, 8H), 2.2 (m, 18H), 1.7 (m, 8H), 0.6–1.4 (m, 24H). n:m = 120:360 was determined by NMR integration.

[0070] Dissolve 10 g (1 equiv.) of the G2 reaction intermediate in 100 mL of tetrahydrofuran solution to obtain an intermediate solution. Separately, dissolve 45.7 g (2 equiv.) of N1,N4-bis(6-bromohexyl)-N1-methaneimino-N1,N4,N4-trimethylbutane-1,4-diammonium (33.7 g, 10 equiv.) in 200 mL of a tetrahydrofuran-methanol mixture (1:1) to obtain a mixed solution. Add the intermediate solution to the above mixed solution and stir the reaction mixture for 2 days. Concentrate the reaction solution and add it to a dialysis bag (permeable to molecules up to 50 kDa). Wash with deionized water until the ionic conductivity of the washings is the same as that of deionized water. Dry and grind to obtain 18.5 g of a light brown powder, which is G2, with a yield of 90.7%. 1 H NMR(500 MHz, DMSO-d6, δ,ppm): 8.0-8.1 (m, 8H), 7.6-8.0 (m, 14H), 7.3-7.4 (m,12H), 7.2-7.3 (m, 11H), 5.2-6.0 (m, 6H), 2.9-3.6 (m, 48H), 2.4 (m, 8H), 1.7(m, 8H), 0.6-1.4 (m, 44H).

[0071] The synthesis method for G3 is as follows:

[0072]

[0073] In a two-necked reaction flask A, 1,1'-binaphthyl (3.3 g, 13.1 mmol) and 7-bromo-1,1,1-trifluoro-2-octanone (10.4 g, 40 mmol) were added and dissolved in 33 mL of dichloromethane with mechanical stirring at room temperature. The reaction system was cooled to 0 °C, and a trifluoromethanesulfonic acid / trifluoroacetic acid mixture (1:1, 45 g) was slowly added dropwise. After the addition was complete, the mixture was stirred at 0 °C for 10 min, and then the reaction system was transferred to a 30 °C water bath.

[0074] Biphenyl (4.0 g, 26 mmol) was dissolved in 67 mL of dichloromethane in a two-necked reaction flask B.

[0075] Once the temperature of reaction flask A reached 30°C, the molecular weight increase was monitored every half hour using gel permeation chromatography. When the average molecular weight reached 10 kDa, the solution from reaction flask B was added to reaction flask A to continue the reaction until the product molecular weight reached 333 K. After washing three times with ethanol, the product was redissolved in 100 mL of tetrahydrofuran, and 40 wt% dimethylamine aqueous solution (5.9 g, 130 mmol) was added. The mixture was stirred for 48 hours, and then a solid was precipitated in anhydrous diethyl ether at 0°C. The precipitate was dried and crushed to obtain 6.5 g of a light brown powder, which is the G3 reaction intermediate, with a yield of 98.1%. 1 ¹H NMR (500 MHz, CDCl₃, δ, ppm): 8.0–8.1 (m, 2H), 7.6–8.0 (m, 16H), 7.3–7.4 (m, 8H), 7.2–7.3 (m, 2H), 2.4 (m, 6H), 2.2 (m, 18H), 1.7 (m, 6H), 0.6–1.4 (m, 24H). n:m = 259:518 was determined by NMR integration.

[0076] G3 reaction intermediate (10 g, 1 equiv.) was dissolved in 100 mL of tetrahydrofuran-methanol (1:1) solution to obtain the intermediate solution. Separately, 4,4'-(dimethyl-1,4-azadiyl)bis(N-(4-bromobutyl)-N,N-dimethylbutane-1-ammonium) (176 g, 10 equiv.) was dissolved in 1200 mL of tetrahydrofuran-methanol mixed solvent (1:1). The intermediate solution was added to this solution at 60 °C, and the reaction was continued for 2 days. After cooling the reaction system to 30 °C, 40 wt% dimethylamine aqueous solution (30 g) was added, and the reaction was continued with stirring for another 2 days.

[0077] The concentrated reaction solution was added to a dialysis bag (permeable to molecules up to 50 kDa) and washed with deionized water until the ionic conductivity of the washing solution was the same as that of deionized water. The solution was dried and pulverized to obtain 26.5 g of a light brown powder, which is G3, with a yield of 96.0%. 1 H NMR (500 MHz, DMSO-d6, δ,ppm): 8.1-8.0 (m, 2H), 7.6-8.2 (m, 16H), 7.2-7.4 (m, 10H), 2.9-3.6 (m, 40H), 2.4 (m, 6H), 2.2 (m, 18H), 1.7 (m, 22H),1.6-1.4 (m, 24H).

[0078] The synthesis method for G4 is as follows:

[0079]

[0080] In a two-necked reaction flask A, 9,10-diphenylanthracene (6.4 g, 19.5 mmol) and 7-bromo-1,1,1-trifluoro-2-nonanone (5.5 g, 20 mmol) were added and dissolved in 65 mL of dichloromethane with mechanical stirring at room temperature. The reaction system was cooled to 0 °C, and a trifluoromethanesulfonic acid / trifluoroacetic acid mixture (1:1, 35 g) was slowly added dropwise. After the addition was complete, the mixture was stirred at 0 °C for 10 min, and then the reaction system was transferred to a 30 °C water bath.

[0081] In a two-necked reaction flask B, 4.5 g (19.5 mmol) of m-terphenyl and 4.4 g (20 mmol) of 5-bromo-1,1,1-trifluoro-2-pentanone were dissolved in 45 mL of dichloromethane. When the temperature of the system in reaction flask A reached 30 °C, the molecular weight increase was monitored by gel permeation chromatography every half hour. When the average molecular weight reached 10 kDa, the solution from reaction flask B was added to reaction flask A, and the reaction continued until the molecular weight of the product reached 328 kDa. The reaction solution was then poured into 1000 mL of cold 1:1 methanol / water solution, precipitating a solid. The solid was collected, washed with deionized water, dried, and crushed to obtain 19 g of a brown powder, which was the G4 reaction intermediate, with a yield of 95.5%. 1 ¹H NMR (500 MHz, DMSO-d⁶, δ, ppm): 8.1–6.5 (m, 28H), 4.2 (m, 2H), 3.2 (m, 2H), 2.4 (m, 4H), 0.6–1.7 (m, 12H). n:m = 322:322 was determined by NMR integration.

[0082] The G4 reaction intermediate (10 g, 1 equiv.) was dissolved in 200 mL of tetrahydrofuran in a three-necked round-bottom flask, followed by the addition of N-methylpiperidine (0.99 g, 0.5 equiv.). The reaction system was protected under nitrogen atmosphere. The reaction system was refluxed at 60 °C for 48 hours. When the reaction became turbid, 100 mL of ethanol was added. TLC analysis confirmed that the N-methylpiperidine reaction was complete. After cooling to 25 °C, N,N-dimethyl-1-(4-vinylphenyl)methylamine (1.58 g, 0.5 equiv.) was added, and the reaction was carried out for 72 hours. The reaction system was poured into 2 L of anhydrous ethanol to obtain a flocculent precipitate. After washing with petroleum ether and drying at low temperature, 10.5 g of brown powder, which was G4, was obtained, with a yield of 83.7%. 1 H NMR (500 MHz, DMSO-d6, δ,ppm): 6.0-8.1 (m, 32H), 5.2-6.5 (m, 3H), 4.5 (m, 2H), 2.9- 3.2 (m, 17H), 2.4 (m, 4H), 0.8-1.7 (m, 18H).

[0083] The preparation principle and microstructure of the anion exchange membrane material provided by this invention are as follows: Figure 1 As shown. Its overall preparation process is as follows: Figure 2 As shown in the figure; the present invention will be further described below with reference to the embodiments.

[0084] Example 1:

[0085] Anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G1

[0086] (1) Preparation of casting solution: Add 0.4 g of G1 powder, 2 mL of DMF, 2 mL of NMP, and 2 mL of DMSO to a 10 mL three-necked flask in sequence. Stir at 600-1000 r / min for 5-10 h at 60℃ to obtain G1 solution. Place filter paper with a pore size of 10 μm in a positive pressure filter and circulate 60℃ circulating water through the filter jacket for 1-3 h to maintain the temperature at 60℃. Then slowly pour in the G1 solution and pressurize to 0.2-0.5 MPa for coarse filtration. Replace the filter paper with a pore size of 0.45 μm in the positive pressure filter, pour in the coarse filtrate, and pressurize to 0.2-0.5 MPa for filtration to obtain casting solution.

[0087] (2) Preparation of spraying solution: Transfer the casting solution to a 100 mL three-necked flask, add 20 mL of IPA, 20 mL of EtOH and 20 mL of MeOH, and stir at 600-1000 r / min for 30-90 min at room temperature to make it evenly mixed and obtain the spraying solution.

[0088] (3) Preparation of chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh: Add 20 g PPS powder, 60 g PS powder and 20 g PEEK powder to a high-speed mixer and mix at 1000-3000 r / min for 30-90 min. After mixing evenly, transfer the powder to an oven at 150-250℃ and dry for 6-8 h. Composite filaments were prepared by melt blending extrusion. The dried mixed powder was added to the extruder feed inlet. The single-screw extruder was set with a screw speed of 20 r / min, zone temperatures of 340℃ (zone 1), 345℃ (zone 2), 360℃ (zone 3), 365℃ (zone 4), 375℃ (zone 5), and an extrusion temperature of 380℃. The traction speed was 10 m / min. After extrusion through the spinneret, the nascent filaments were stretched three times in a stretching chamber at 200-250℃. After cooling and solidification, a composite filament with a diameter of 45 μm was obtained. This filament was then woven into a 100-400 mesh mesh using a braiding machine. The woven mesh was then placed on a hot press at a temperature of 170-200℃, a pressure of 10 MPa, and a pressing time of 2-5 min to obtain the composite mesh. At 30℃, add 300 mL of 98% concentrated sulfuric acid to a 500 mL beaker. Cut a composite wire mesh of 10 cm × 10 cm or larger and immerse it in the concentrated sulfuric acid for 30-60 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain sulfonated composite wire mesh. Add 100 mL of methanesulfonic acid, 50 mL of concentrated sulfuric acid, and 50 mL of chloromethyl ethyl ether to a 500 mL beaker. Stir and mix thoroughly under ice bath conditions. Immerse the sulfonated composite wire mesh in the solution for 60-90 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh.

[0089] (4) Preparation of anion exchange membrane based on chemical grafting of G1 onto chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh: A PET membrane with a thickness of 100 μm and a size of 5.2 cm × 5.2 cm was placed on a vacuum base plate with heating and temperature control function. Then, a chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh with a thickness of 45 μm and a size of 5 cm × 5 cm was fixed on the PET membrane. The vacuum pump was turned on to maintain the pressure inside the vacuum base plate at 0.02-0.04 MPa, so that the PET membrane carrying the composite wire mesh was tightly adsorbed on the vacuum base plate. The temperature of the vacuum base plate was adjusted to 60-80℃. Add the spraying solution to the spray gun, adjust the air pressure to 0.2-0.6 MPa, the air flow rate to 10-100 L / min, the liquid flow rate to 0.1-1 mL / min, and the spray gun movement speed to 1-5 cm / min. Spray the solution onto the composite mesh. After spraying 2-6 mL of solution, allow it to stand and heat for 10-30 min to allow the solvent to evaporate completely. After spraying 33 mL of solution, flip the composite mesh and repeat the above spraying process until the spraying solution is used up. Finally, an anion exchange membrane with a thickness of 80 μm based on the chemical grafting of G1 onto a chloromethylated PPS:PS:PEEK=1:3:1 composite mesh is obtained.

[0090] Example 2: Anion exchange membrane based on quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G2

[0091] (1) Preparation of casting solution: Add 0.4 g of G2 powder, 2 mL of DMF, 2 mL of NMP, and 2 mL of DMSO to a 10 mL three-necked flask in sequence, and stir at 600-1000 r / min for 5-10 h at 60℃. Place a 10 μm pore size filter paper in a positive pressure filter, and circulate 60℃ circulating water through the filter jacket for 1-3 h to maintain the temperature at 60℃. Then slowly pour in the above G2 solution, pressurize to 0.2-0.5 MPa for coarse filtration, replace the filter paper with a 0.45 μm pore size filter paper in the positive pressure filter, pour in the coarse filtrate, pressurize to 0.2-0.5 MPa for filtration, and obtain the casting solution.

[0092] (2) Preparation of spraying solution: Transfer the casting solution to a 100 mL three-necked flask, add 20 mL of IPA, 20 mL of EtOH and 20 mL of MeOH, and stir at 600-1000 r / min for 30-90 min at room temperature to make it evenly mixed and obtain the spraying solution.

[0093] (3) Preparation of quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh: Add 20 g PPS powder, 60 g PS powder and 20 g PEEK powder to a high-speed mixer and mix at 1000-3000 r / min for 30-90 min. After mixing evenly, transfer the powder to an oven at 150-250℃ and dry for 6-8 h. Composite filaments were prepared by melt blending extrusion. The dried mixed powder was added to the extruder feed inlet. The single-screw extruder was set with a screw speed of 20 r / min, zone temperatures of 340℃ (zone 1), 345℃ (zone 2), 360℃ (zone 3), 365℃ (zone 4), 375℃ (zone 5), and an extrusion temperature of 380℃. The traction speed was 10 m / min. After extrusion through the spinneret, the nascent filaments were stretched three times in a stretching chamber at 200-250℃. After cooling and solidification, a composite filament with a diameter of 45 μm was obtained. This filament was then woven into a 100-400 mesh mesh using a braiding machine. The woven mesh was then placed on a hot press at a temperature of 170-200℃, a pressure of 10 MPa, and a pressing time of 2-5 min to obtain the composite mesh. At 30℃, add 300 mL of 98% concentrated sulfuric acid to a 500 mL beaker. Cut a composite wire mesh of 10 cm × 10 cm or larger and immerse it in the concentrated sulfuric acid for 30-60 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain sulfonated composite wire mesh. Add 100 mL of methanesulfonic acid, 50 mL of concentrated sulfuric acid, and 50 mL of chloromethyl ethyl ether to a 500 mL beaker. Stir and mix thoroughly under ice bath conditions. Immerse the sulfonated composite wire mesh in the solution for 60-90 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh. Add 10 g of N-4-vinylphenyl-N,N-dimethylamine and 200 mL of NMP to a 500 mL beaker. Stir and mix thoroughly at 80 °C. Then add chloromethylated composite wire mesh and soak for 6-10 h. After soaking, remove and wash with deionized water 2-3 times. Dry at 80 °C for 6 h to obtain quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh.

[0094] (4) Preparation of anion exchange membrane based on chemical grafting of G2 onto quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh: A PET membrane with a thickness of 100 μm and a size of 5.2 cm × 5.2 cm was placed on a vacuum base plate with heating and temperature control function. A quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh with a thickness of 45 μm and a size of 5 cm × 5 cm was then fixed on the PET membrane. The vacuum pump was turned on to maintain the pressure inside the vacuum base plate at 0.02-0.04 MPa, so that the PET membrane carrying the composite wire mesh was tightly adsorbed on the vacuum base plate. The temperature of the vacuum base plate was adjusted to 60-80℃. Add the spraying solution to the spray gun, adjust the air pressure to 0.2-0.6 MPa, the air flow rate to 10-100 L / min, the liquid flow rate to 0.1-1 mL / min, and the spray gun movement speed to 1-5 cm / min. Spray the solution onto the composite mesh. After spraying 2-6 mL of solution, allow it to stand and heat for 10-30 min to allow the solvent to evaporate completely. After spraying 33 mL of solution, flip the composite mesh and repeat the above spraying process until the spraying solution is used up. Finally, an anion exchange membrane with a thickness of 80 μm based on quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite mesh chemically grafted with G2 is obtained.

[0095] Example 3: Anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G3

[0096] The preparation method of Example 1 is the same, except that in step (1), G1 powder is replaced with an equal mass of G3 powder to prepare an anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh chemical grafting of G3.

[0097] Example 4: Anion exchange membrane based on quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G4

[0098] The preparation method of Example 2 is the same, except that in step (1), G2 powder is replaced with an equal mass of G4 powder to prepare an anion exchange membrane based on quaternary ammonium styrene-based PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G4.

[0099] Example 5: Anion exchange membrane based on bromomethylated PPS:PS:PEEK=1:3:1 composite wire mesh chemically grafted with G1

[0100] The preparation method of Example 1 is the same, except that in step (3), the chloromethylating agent chloromethyl ethyl ether is replaced with an equal amount of bromomethylating agent bromomethyl ethyl ether to prepare an anion exchange membrane based on bromomethylated PPS:PS:PEEK=1:3:1 composite wire mesh chemical grafting G1.

[0101] Example 6: Anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:1:3 composite wire mesh chemically grafted with G1

[0102] The preparation method is the same as in Example 1, except that in step (3), the ratio of mixed powder is adjusted to PPS:PS:PEEK=1:1:3 to prepare an anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:1:3 composite wire mesh chemical grafting G1.

[0103] Comparison with Example 1: Anion exchange membrane with PPS:PS:PEEK = 1:3:1 composite wire mesh support layer based on G1 & G2, without functionalization treatment.

[0104] (1) Preparation of casting solution: Add 0.2 g of G1 powder, 0.2 g of G2 powder, 2 mL of DMF, 2 mL of NMP, and 2 mL of DMSO to a 10 mL three-necked flask in sequence, and stir at 600-1000 r / min for 5-10 h at 60℃. Place a 10 μm pore size filter paper in a positive pressure filter, and circulate 60℃ circulating water through the filter jacket for 1-3 h to maintain the temperature at 60℃. Then slowly pour in the above G1 & G2 mixed solution, pressurize to 0.2-0.5 MPa for coarse filtration, replace the filter paper with a 0.45 μm pore size filter paper in the positive pressure filter, pour in the coarse filtrate, pressurize to 0.2-0.5 MPa for filtration, and obtain the casting solution.

[0105] (2) Preparation of spraying solution: Transfer the casting solution to a 100 mL three-necked flask, add 20 mL of IPA, 20 mL of EtOH and 20 mL of MeOH, and stir at 600-1000 r / min for 30-90 min at room temperature to make it evenly mixed and obtain the spraying solution.

[0106] (3) Preparation of composite wire mesh of PPS:PS:PEEK=1:3:1: Add 20 g PPS powder, 60 g PS powder and 20 g PEEK powder to a high-speed mixer and mix at 1000-3000 r / min for 30-90 min. After mixing evenly, transfer the powder to an oven at 150-250℃ and dry for 6-8 h. Composite filaments were prepared by melt blending extrusion. The dried mixed powder was added to the extruder feed inlet. The single-screw extruder was set with a screw speed of 20 r / min, zone temperatures of 340℃ (zone 1), 345℃ (zone 2), 360℃ (zone 3), 365℃ (zone 4), 375℃ (zone 5), and an extrusion temperature of 380℃. The traction speed was 10 m / min. After extrusion through the spinneret, the nascent filaments were stretched three times in a stretching chamber at 200-250℃. After cooling and solidification, a composite filament with a diameter of 45 μm was obtained. This filament was then woven into a 100-400 mesh mesh using a braiding machine. The woven mesh was then placed on a hot press at a temperature of 170-200℃, a pressure of 10 MPa, and a pressing time of 2-5 min, resulting in a composite mesh with a PPS:PS:PEEK ratio of 1:3:1.

[0107] (4) Preparation of anion exchange membrane based on G1 & G2 PPS:PS:PEEK=1:3:1 composite wire mesh support layer: A PET membrane with a thickness of 100 μm and a size of 5.2 cm × 5.2 cm was placed on a vacuum base plate with heating and temperature control function. A PPS:PS:PEEK=1:3:1 composite wire mesh with a thickness of 45 μm and a size of 5 cm × 5 cm was then fixed on the PET membrane. The vacuum pump was turned on to maintain the pressure inside the vacuum base plate at 0.02-0.04 MPa, so that the PET membrane carrying the composite wire mesh was tightly adsorbed on the vacuum base plate. The temperature of the vacuum base plate was adjusted to 60-80℃. Add the spraying solution to the spray gun, adjust the air pressure to 0.2-0.6 MPa, the air flow rate to 10-100 L / min, the liquid flow rate to 0.1-1 mL / min, and the spray gun movement speed to 1-5 cm / min. Spray the solution onto the composite mesh. After spraying 2-6 mL of solution, allow it to stand and heat for 10-30 min to allow the solvent to evaporate completely. After spraying 33 mL of solution, flip the composite mesh and repeat the above spraying process until the spraying solution is used up. Finally, an anion exchange membrane with a thickness of 80 μm based on G1&G2 PPS:PS:PEEK=1:3:1 composite mesh support layer is obtained.

[0108] Comparison Example 2: Anion exchange membrane with PPS:PS:PEEK = 1:1:3 composite wire mesh support layer based on G1 & G2, without functionalization treatment.

[0109] Referring to Comparative Example 1, the only difference is that the mesh ratio is adjusted to PPS:PS:PEEK=1:1:3, resulting in a composite mesh support layer anion exchange membrane based on G1 & G2 with a PPS:PS:PEEK=1:1:3 ratio.

[0110] Comparative Example 3: Anion exchange membrane with PP membrane support layer based on G1 & G2, without functionalization treatment.

[0111] Referring to Comparative Example 1, the only difference is that the aromatic composite mesh is replaced with a PP membrane (polypropylene porous membrane) to obtain an anion exchange membrane based on the PP membrane support layer of G1 & G2.

[0112] Comparative Example 4: ePTFE membrane support layer anion exchange membrane based on G1 & G2

[0113] Referring to Comparative Example 1, the only difference is that the aromatic composite mesh is replaced with an ePTFE membrane (polytetrafluoroethylene porous membrane) to obtain an anion exchange membrane based on the G1&G2 ePTFE membrane support layer.

[0114] Comparative Example 5: Anion exchange membrane based on chloromethylated PPS:PS:PEEK = 1:3:1 composite wire mesh grafted with PEI & 1,12-dibromododecane

[0115] (1) Preparation of casting solution: Add 0.52 g of PEI powder, 1.80 g of 1,12-dibromododecane, 2 mL of DMF, 2 mL of NMP, and 2 mL of DMSO to a 10 mL three-necked flask in sequence, and stir at 600-1000 r / min for 5-10 h at 60℃. Place a 10 μm pore size filter paper in a positive pressure filter, and circulate 60℃ circulating water through the filter jacket for 1-3 h to maintain the temperature at 60℃. Then slowly pour in the above mixed solution, pressurize to 0.2-0.5 MPa for coarse filtration, replace the filter paper with a 0.45 μm pore size filter paper in the positive pressure filter, pour in the coarse filtrate, pressurize to 0.2-0.5 MPa for filtration, and obtain the casting solution.

[0116] (2) Preparation of spraying solution: Transfer the casting solution to a 100 mL three-necked flask, add 20 mL of IPA, 20 mL of EtOH and 20 mL of MeOH, and stir at 600-1000 r / min for 30-90 min at room temperature to make it evenly mixed and obtain the spraying solution.

[0117] (3) Preparation of chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh: Add 20 g PPS powder, 60 g PS powder and 20 g PEEK powder to a high-speed mixer and mix at 1000-3000 r / min for 30-90 min. After mixing evenly, transfer the powder to an oven at 150-250℃ and dry for 6-8 h. Composite filaments were prepared by melt blending extrusion. The dried mixed powder was added to the extruder feed inlet. The single-screw extruder was set with a screw speed of 20 r / min, zone temperatures of 340℃ (zone 1), 345℃ (zone 2), 360℃ (zone 3), 365℃ (zone 4), 375℃ (zone 5), and an extrusion temperature of 380℃. The traction speed was 10 m / min. After extrusion through the spinneret, the nascent filaments were stretched three times in a stretching chamber at 200-250℃. After cooling and solidification, a composite filament with a diameter of 45 μm was obtained. This filament was then woven into a 100-400 mesh mesh using a braiding machine. The woven mesh was then placed on a hot press at a temperature of 170-200℃, a pressure of 10 MPa, and a pressing time of 2-5 min to obtain the composite mesh. At 30℃, add 300 mL of 98% concentrated sulfuric acid to a 500 mL beaker. Cut a composite wire mesh of 10 cm × 10 cm or larger and immerse it in the concentrated sulfuric acid for 30-60 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain sulfonated composite wire mesh. Add 100 mL of methanesulfonic acid, 50 mL of concentrated sulfuric acid, and 50 mL of chloromethyl ethyl ether to a 500 mL beaker. Stir and mix thoroughly under ice bath conditions. Immerse the sulfonated composite wire mesh in the solution for 60-90 seconds. After removal, rinse with deionized water 2-3 times, ensuring the pH of the washing solution is around 7. Dry at 70℃ for 6 hours to obtain chloromethylated PPS:PS:PEEK=1:3:1 composite wire mesh.

[0118] (4) Preparation of anion exchange membrane based on chloromethylated PPS:PS:PEEK=1:3:1 composite mesh grafted with PEI & 1,12-dibromododecane: A PET membrane with a thickness of 100 μm and a size of 5.2 cm × 5.2 cm was placed on a vacuum base plate with heating and temperature control function. Then, a chloromethylated PPS:PS:PEEK=1:3:1 composite mesh with a thickness of 45 μm and a size of 5 cm × 5 cm was fixed on the PET membrane. The vacuum pump was turned on to maintain the pressure in the vacuum base plate at 0.02-0.04 MPa, so that the PET membrane carrying the composite mesh was tightly adsorbed on the vacuum base plate. The temperature of the vacuum base plate was adjusted to 60-80℃. Add the spraying solution to the spray gun, adjust the air pressure to 0.2-0.6 MPa, the air flow rate to 10-100 L / min, the liquid flow rate to 0.1-1 mL / min, and the spray gun movement speed to 1-5 cm / min. Spray the solution onto the composite mesh. After spraying 2-6 mL of solution, allow it to stand and heat for 10-30 min to allow the solvent to evaporate completely. After spraying 33 mL of solution, flip the composite mesh and repeat the above spraying process until the spraying solution is used up. Finally, an anion exchange membrane with a thickness of 80 μm based on a chloromethylated PPS:PS:PEEK=1:3:1 composite mesh grafted with PEI & 1,12-dibromododecane is obtained.

[0119] Comparative Example 6: Homogeneous Anion Exchange Membrane Based on G1 & G2

[0120] (1) Preparation of casting solution: Add 0.2 g of G1 powder, 0.2 g of G2 powder, 2 mL of DMF, 2 mL of NMP, and 2 mL of DMSO to a 10 mL three-necked flask in sequence, and stir at 600-1000 r / min for 5-10 h at 60℃. Place a 10 μm pore size filter paper in a positive pressure filter, and circulate 60℃ circulating water through the filter jacket for 1-3 h to maintain the temperature at 60℃. Then slowly pour in the above G1 & G2 mixed solution, pressurize to 0.2-0.5 MPa for coarse filtration, replace the filter paper with a 0.45 μm pore size filter paper in the positive pressure filter, pour in the coarse filtrate, pressurize to 0.2-0.5 MPa for filtration, and obtain the casting solution.

[0121] (2) Preparation of spraying solution: Transfer the casting solution to a 100 mL three-necked flask, add 20 mL of IPA, 20 mL of EtOH and 20 mL of MeOH, and stir at 600-1000 r / min for 30-90 min at room temperature to make it evenly mixed and obtain the spraying solution.

[0122] (3) Preparation of homogeneous anion exchange membrane based on G1 & G2: A PET membrane with a thickness of 100 μm and a size of 5.2 cm × 5.2 cm was placed on a vacuum base plate with heating and temperature control function. The vacuum pump was turned on to maintain the pressure inside the vacuum base plate at 0.02-0.04 MPa, so that the PET membrane was tightly adsorbed on the vacuum base plate, and the temperature of the vacuum base plate was adjusted to 60-80℃. The spraying solution was added to the spray gun, and the air pressure of the spray gun was adjusted to 0.2-0.6 MPa, the gas output was 10-100 L / min, the liquid output was 0.1-1 mL / min, and the spray gun moving speed was 1-5 cm / min. The solution was sprayed onto the PET. After spraying 2-6 mL of solution, the mixture was allowed to stand and heat for 10-30 min to allow the solvent to evaporate completely. After spraying 33 mL of solution, the composite mesh is flipped over and the spraying process is repeated until the spraying solution is used up, finally obtaining a homogeneous anion exchange membrane based on G1 & G2 with a thickness of 80 μm.

[0123] The molecular weight determination method during the synthesis process is as follows:

[0124] Take a small amount of sample (10 mg) and dissolve it in chromatographic grade tetrahydrofuran (1 mL). Filter the solution and take 50 μL of the filtrate. Remove any obvious air bubbles from the injection needle and inject 10 μL of the liquid into a liquid chromatograph EClassical 3100. Use gel permeation chromatography with tetrahydrofuran as the mobile phase at a flow rate of 1 mL / min and a temperature of 30 °C.

[0125] The NMR testing methods involved in the synthesis process are as follows:

[0126] 10 mg of sample was dissolved in 1 mL of the corresponding deuterated solvent. The test equipment used was a Burker 500 MHz NMR instrument with T1=2S and at least 16 scans.

[0127] The light transmittance and lateral section microscopy images of the samples in Examples 1-6 and Control Examples 1-6 are as follows: Figure 3 As shown. Examples 1-6 have good light transmittance, and the side section images show that the composite membrane structure is uniform, and the supporting material and electrolyte material are tightly bonded.

[0128] The composite membranes prepared in Examples 1-6 and Comparative Examples 1-6 were subjected to performance tests, and the test methods are as follows:

[0129] AC impedance test:

[0130] Electrochemical impedance spectroscopy (EIS) was performed on the membrane sample using an electrochemical workstation (Chenhua CHI660E). The membrane sample (4 cm long, 1 cm wide) was securely fixed in a specially designed electrochemical test cell (four electrodes, platinum as the electrode material), ensuring tight contact between the membrane and the electrode system. Before testing, the test solution (such as an electrolyte solution of a specific concentration) was injected into the test cell to fully wet the membrane sample. If the test temperature was not at room temperature, the sample was allowed to equilibrate in the electrolyte for at least 30 minutes to reach the test temperature. The test parameters of the electrochemical workstation were set, with the scan frequency range set to 1*10⁻⁶. 6 The AC excitation signal amplitude was 2 sec and the voltage was 100 mV, ranging from Hz to 0.1 Hz. The impedance value was obtained when the phase angle was closest to 0°, and the ionic conductivity was calculated based on the sample size and thickness.

[0131] Swelling rate test:

[0132] Cut a 5 cm × 5 cm dry film sample, measure and record the thickness using a film thickness gauge, then immerse the sample in 200 mL of deionized water and store it at 80 °C for 48 h to allow it to fully swell. After that, measure the length, width and thickness of the film, and calculate the swelling rate based on the volume change before and after swelling (swelling rate = (swelled volume – initial volume) / initial volume × 100%).

[0133] Tensile strength test:

[0134] Tensile strength tests were performed on membrane samples using a universal tensile testing machine (Instron-3367, Instron, USA). The membrane samples were precisely cut into standard dumbbell shapes, with dimensions strictly conforming to the national standard GB / T 1040.3-2 (length 150 mm, width 20 mm, thickness 20-60 μm). The samples were mounted between the upper and lower clamps of the universal tensile testing machine, and the tensile rate was set to 50 mm / min. After starting the test, the tensile force acting on the sample and the corresponding elongation were monitored and recorded in real time until the sample broke. The tensile strength of the membrane was calculated based on the recorded data (the tensile force at break divided by the original cross-sectional area of ​​the sample).

[0135] Alkali stability test:

[0136] Cut a 2 cm × 2 cm sample of dried film, weigh and record its mass, then immerse it in 20 mL of 1 M KOH solution and store it at 80 °C for 30 days. After removal, wash it with deionized water until the conductivity of the washing solution is 2-3 μS / cm, dry it and weigh it. Calculate the mass loss rate based on the mass change before and after immersion in the alkaline solution (mass loss rate = (initial mass – mass after aging) / initial mass × 100%).

[0137] Water electrolysis performance test:

[0138] Anion exchange membrane water electrolysis tests were conducted using the membranes obtained in Example 1 and Comparative Example 6:

[0139] Cut a suitable size (generally 5 cm × 5 cm) of U-shaped PTFE gasket, electrode, and anion exchange membrane of the same size; fix the current collector to the cathode flow channel plate through the positioning hole with bolts and place it in the fixture; place the PTFE on the flow channel area, and place the cathode electrode in the central hollow; pass the anode flow channel plate and current collector through the positioning hole to cover the PTFE, and tighten the nuts and bolts through the positioning hole to fix the entire test electrolytic cell, and adjust the torque of the test cell with a torque wrench; connect the installed electrolytic cell to the corresponding inlet and outlet water pipes according to the anode and cathode, and turn on the circulation pump and set the flow rate to circulate the heated electrolyte (0.2 M KOH) into the system; connect the positive and negative terminals of the power supply and the voltage, current, and temperature detection devices to the test cell, set the program and current (5-25 A), and turn on the pump to circulate and heat the system to the corresponding temperature. Turn on the power supply and the corresponding program to start the electrolysis experiment and collect operating parameters such as temperature, current, and voltage. Figure 6 The test result was 1 A / cm. 2 Test results at 60℃ under current density.

[0140] The ionic conductivity test results of Examples 1-6 and Comparative Examples 1-6 are as follows: Figure 5 A (60℃) and Figure 5 As shown in B (80℃), the tensile strength test results are as follows. Figure 5 As shown in C in the figure, the tensile strength of Examples 1-6 is significantly higher than that of Control Examples 1-6, and the ionic conductivity is comparable to that of the homogeneous membrane (Control Example 6).

[0141] The performance parameters of anion exchange membranes based on different supporting materials and ionic electrolytes are shown in Table 1 below:

[0142] Table 1

[0143]

[0144] The above examples compared the compatibility of support materials with different functionalized structures (Examples 1-5), mesh support materials with different component ratios (Examples 1 and 6), unfunctionalized support materials (Comparative Examples 1-2), and thin-film composite materials (Comparative Examples 3-4) with different rigid anion exchange materials. The compatibility of flexible anion exchange materials with chloromethylated mesh support materials was also compared (Comparative Example 5). Finally, the performance improvement of the material with and without mesh was compared (Comparative Example 6). It was found that adding a suitable mesh (a polymer mesh with an aromatic skeleton) could increase the mechanical strength of the ion exchange material from 23 MPa to nearly 60 MPa, while significantly improving dimensional stability and alkali stability, but with a relatively small loss of ionic conductivity (Comparative Examples 1-2).

[0145] Furthermore, by chemically grafting anion exchange materials onto functionalized mesh support materials (Examples 1-6), the mechanical strength can be increased to 90 MPa, further improving dimensional stability and alkali stability. The formation of a micron-scale phase-separated structure enhances ion conductivity, resulting in an ionic conductivity nearly comparable to that without the composite material (Comparative Example 6). Compared to Comparative Examples 3-4, other thin-film composite materials offer benefits to overall mechanical strength but suffer significant losses in ionic conductivity, consistent with literature reports. Meanwhile, the composite membrane materials of Comparative Examples 3-5 exhibit severe delamination under strong alkali and high-temperature conditions. Compared to Examples 1-6, the stability of Comparative Example 6 is significantly lower, indicating that the support material with an aromatic structure has better compatibility and stability with the aromatic rigid ionic electrolyte material. Experimental tests compared the water electrolysis performance of Examples 1 and 6 at a current density of 1 A / cm². 2 Under these conditions, the initial voltage of both was 1.75 V. However, in Control Example 6, the voltage fluctuated greatly after 2500 h due to the degradation and damage of the membrane in the alkaline environment. In contrast, Example 1 was extremely stable during the long-term test of 6000 h, which proved that the membrane material prepared by the grafting method has stronger alkaline stability and mechanical strength, and greatly improves its service life.

[0146] This invention points out that when a rigid anion exchange material is grafted onto the surface of a rigid polymer web, the composite membrane material exhibits a significant improvement in mechanical strength without loss of ionic conductivity. The strong chemical bonding results in excellent stability under the strongly alkaline and high-temperature conditions of AEMWE water electrolysis. This invention provides a polymer membrane material with performance comparable to Nafion (PEMWE membrane), which holds promise for further advancing the AEMWE water electrolysis technology.

Claims

1. A chemically grafted and reinforced double-through anion exchange composite membrane, characterized in that, include: A continuous porous support material layer, wherein the porous support material is a rigid polymer material with an aromatic structure and a pore size range of 1-1000 μm; A continuous anion exchange material, wherein the anion exchange material fills the pores of the porous support material layer; The surface of the porous support material has functional groups, and the support material and the anion exchange material are grafted together through chemical bonds formed by the functional groups.

2. The chemically grafted reinforced double-penetrating anion exchange composite membrane according to claim 1, characterized in that, The functional group is selected from at least one of Cl, Br, or carbon-carbon double bonds.

3. The chemically grafted reinforced double-penetrating anion exchange composite membrane according to claim 2, characterized in that, The porous support material is selected from one or more of the following polymers: Polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene terpolymer, acrylonitrile-styrene-acrylate copolymer, methyl methacrylate-acrylonitrile-butadiene-styrene copolymer, styrene-methyl methacrylate copolymer, syndiotactic polystyrene, polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfone, polyetheretherketone, polyetherketoneketone, polyetherketone, polyphenylene sulfide, high-temperature nylon, poly(m-xylenedimethylhexamethylene)-adipamide, sulfonated polyetheretherketone, sulfonated polyethersulfone, sulfonated polyphenylene sulfone, polystyrene sulfonic acid and its salts, polybenzimidazole, polypropylene, polyethylene, tetrafluoroethylene, polyvinylidene fluoride, cellulose acetate.

4. The chemically grafted reinforced double-penetrating anion exchange composite membrane according to claim 3, characterized in that, The porous support material layer has a woven mesh structure, which is obtained by mixing and melting the porous support material to prepare fine filaments and then weaving them; the porosity of the porous support material layer is above 40%, and the thickness ranges from 5 to 100 μm.

5. The chemically grafted reinforced double-penetrating anion exchange composite membrane according to claim 1, characterized in that, The anion exchange material is selected from one or more compounds of the general formula (I): （I） Where n and m are the number of repeating units; n is an integer from 1 to 2000; m is an integer from 1 to 2000; Ar1 and Ar2 are each independently selected from the following structural segments: 、 、 The values ​​of x1 and x2 range from 0 to 10; LK1 and LK2 are linking groups, each independently selected from... or ; EWG is selected from one of the following structural segments: ； R1 is the active group used in the crosslinking reaction, selected from one of the following structural segments: R2 is an ionic group or the same as the crosslinking group R1. If it is an ionic group, the cationic group is selected from one of the following structural segments: The anionic group is selected from one of the following structural segments: 。 6. The chemically grafted reinforced double-penetrating anion exchange composite membrane according to claim 5, characterized in that, Ar1 is selected from or R1 is selected from or .

7. A method for preparing a chemically grafted reinforced double-penetrating anion exchange composite membrane as described in any one of claims 1-6, characterized in that, Includes the following steps: Functionalization treatment is applied to porous support materials to introduce functional groups selected from Cl, Br, or carbon-carbon double bonds onto their surface; Anion exchange material is dissolved in a polar aprotic solvent and diluted with a low-boiling-point organic solvent to prepare a spraying solution. The ultrasonic spraying process is used to load the spraying solution onto both sides of the porous support material, and the thickness is adjusted by controlling the number of spraying cycles. The porous support material is subjected to a heating and drying process, which allows the functional groups on the surface of the porous support material to form chemical bonds with the anion exchange material, thereby obtaining the chemically grafted and reinforced double-penetrating anion exchange composite membrane.

8. The preparation method according to claim 7, characterized in that, The mass fraction of the spraying solution is 0.1-1%; the polar aprotic solvent is selected from one or more of DMF, NMP, and DMSO; the low-boiling-point organic solvent is selected from one or more of IPA, EtOH, MeOH, THF, and EtOAc.

9. The preparation method according to claim 7, characterized in that, The heating and drying temperature is 50-100℃.

10. The application of the chemically grafted and enhanced double-penetrating anion exchange composite membrane as described in any one of claims 1-6 in scenarios such as hydrogen production by water electrolysis, fuel cells, flow batteries, carbon dioxide electroreduction, or water treatment.

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