Preparation method and application of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane

Abstract

The present invention discloses a preparation method and application of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane, belonging to the technical field of energy conversion. In the present invention, sulfonated polybenzimidazole is used as a polymer matrix, and benzimidazole-based covalent organic framework is in-situ synthesized by a thermal-induced solvent evaporation method to prepare a composite alkaline ion solvent membrane with a benzimidazole structural unit as the main body. The sulfonic acid groups on the polymer matrix can interact with amino groups to mediate the positioning to achieve long-range regular and ordered sub-nanometer pores. At the same time, the enrichment of benzimidazole functional groups can improve the hydroxide conductivity of the composite ion solvent membrane. Meanwhile, the in-situ generation of benzimidazole-based covalent organic framework fillers in the membrane can make it have good compatibility and uniformity with the polybenzimidazole matrix, and enhance the mechanical properties of the membrane, having good application prospects in energy conversion fields such as alkaline water electrolysis, zinc-air batteries, carbon dioxide electroreduction, and ammonia fuel cells.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy conversion, and particularly relates to a preparation method and application of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Background Art

[0002] Green hydrogen production technologies include hydrogen production by electrolyzing water using renewable resources such as wind power, hydropower, and solar energy, solar photolysis of water for hydrogen production, and biomass hydrogen production. Among them, hydrogen production by electrolyzing water using renewable energy is the most widely used and technically mature method. Currently, there are various technical routes for electrolyzing water to produce hydrogen, including: alkaline electrolysis water technology (ALK), proton exchange membrane electrolysis water technology (PEM), anion exchange membrane electrolysis water technology (AEM), and solid oxide electrolysis water technology (SOEC). Among them, the acidic conditions of proton exchange membrane electrolyzers have relatively high requirements for electrolyzer devices and catalysts, and the overall cost is expensive. The conditions for solid oxide electrolysis of water are harsh and the operating temperature is relatively high. Both are not easy to achieve large-scale commercialization. Anion exchange membrane electrolyzers use anion exchange membranes as electrolytes, integrating the low cost of ALK and the simplicity and high efficiency of PEM electrolyzers. It is the most advanced electrolysis water technology at present. However, as one of the core components of the electrolyzer, the performance of the anion exchange membrane material directly affects the output performance of the electrolyzer. Although AEM has made great progress in ionic conductivity in recent years, its alkali resistance stability is still not satisfactory.

[0003] Alkaline ion solvent membranes combine the advantages of traditional diaphragms and anion exchange membranes, forming a ternary homogeneous system of electrolyte / water / polymer during polymerization by doping with alkali. Its polymer backbone does not contain easily degradable quaternary ammonium salt groups, which can greatly improve its alkali resistance stability. Polybenzimidazole (PBI) is a high-performance heterocyclic polymer with high thermal stability, excellent oxidation resistance, and mechanical properties, and its preparation process is simple. The imidazole ring in the main chain has amphiphilic properties, so it can be deprotonated by alkaline electrolytes, absorb electrolytes, and conduct ions. However, it needs to absorb a high concentration (10 - 35 wt.%) of alkali solution to obtain a higher ionic conductivity, so as to ensure a high electrolyzer output efficiency. However, the doping of high-concentration alkali will sharply reduce the mechanical properties of the membrane. Therefore, the current polybenzimidazole-based alkaline ion solvent membranes still need further technical improvement.

[0004] Introducing sulfonic acid groups onto the molecular chain of polybenzimidazole can increase ion transport sites and significantly improve the ionic conductivity of ion-solvating membrane materials in low-concentration alkaline solutions. However, due to the water-absorbing nature of sulfonic acid groups, the membrane materials suffer from serious swelling problems and poor mechanical properties [Adv. Energy Mater. 2023, 2302966]. Therefore, controlling the dimensional stability of sulfonated polybenzimidazole ion-solvating membrane materials is crucial for obtaining high-performance ion-solvating membrane materials.

[0005] Chemically grafting or crosslinking polybenzimidazole is an effective method to improve its mechanical properties, but this also consumes the active sites of the imidazole ring in its molecular structure, and the flexibility defects of the polymer chain segments still cannot be overcome. Incorporating functionalized nanomaterials, such as covalent organic frameworks (COFs) and covalent metal frameworks, into the polymer matrix. Among them, COFs have highly ordered sub-nanoscale pores inside, can pre-design relevant functional groups, and have excellent chemical / thermal stability and dimensional stability. Therefore, they are ideal platforms for anion conduction. In recent years, introducing COF nanofilers into the polymer matrix has been proven to be an effective way to improve the comprehensive performance of membranes, but the compatibility problem between nanoparticles and the polymer matrix still remains. Summary of the Invention

[0006] The present invention synthesizes sulfonated polybenzimidazole by a one-step method. The preparation process is simple, and the sulfonic acid groups are directly introduced into the main chain molecule on the dicarboxylic acid monomer without occupying the active sites of the imidazole ring. The present invention in-situ synthesizes benzimidazole-based covalent organic frameworks in the membrane by a thermal-induced solvent evaporation method, which can effectively improve the mechanical properties and dimensional stability of the membrane. At the same time, the ordered arrangement of benzimidazole groups can provide a fast channel for ion conduction. The main structural units of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion-solvating membrane prepared by the present invention are all benzimidazole, and the polymer transitions from linear to grid-like ultra-high crosslinking. The membrane is homogeneous, transparent, and has strong compatibility, providing a new preparation method for alkaline ion-solvating membranes. At the same time, the alkaline ion-solvating membrane material (i.e., sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion-solvating membrane) prepared by the present invention can be applied not only in the field of alkaline water electrolysis, but also can be extended to energy conversion technology fields such as fuel cells, electroreduction of carbon dioxide, and zinc-air batteries, and has considerable application prospects.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] One of the technical solutions of the present invention:

[0009] A sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion-solvating membrane, prepared from sulfonated polybenzimidazole and benzimidazole-based covalent organic frameworks;

[0010] The structural formula of the sulfonated polybenzimidazole is shown in Formula (1):

[0011]

[0012] Wherein, x represents the sulfonation degree, 0 < x ≤ 80;

[0013] SAr 1 is any one of the following structural units:

[0014]

[0015] Ar 2 is any one of the following structural units:

[0016]

[0017] The benzimidazole-based covalent organic framework is synthesized from an aryl tricarbaldehyde monomer and an aryl tetramine monomer. The aryl tricarbaldehyde monomer is any one of the following structures:

[0018]

[0019] The aryl tetramine monomer is any one of the following structures:

[0020]

[0021] The second technical solution of the present invention:

[0022] The present invention also provides a method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. The sulfonated polybenzimidazole is prepared by a polymerization reaction. The aryl tricarbaldehyde monomer and the aryl tetramine monomer are added to the sulfonated polybenzimidazole solution to obtain a casting solution. The casting solution is prepared into a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane by thermal-induced solvent evaporation. The sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is obtained after alkali treatment to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane.

[0023] In the present invention, sulfonated polybenzimidazole is used as the polymer matrix, and benzimidazole-based covalent organic frameworks are in-situ synthesized by a thermal-induced solvent evaporation method to prepare a composite alkaline ion-solvating membrane with benzimidazole structural units as the main body. The sulfonic acid groups on the polymer matrix can interact with amino groups to mediate positioning and achieve long-range regular and ordered sub-nanoscale pores. At the same time, the enrichment of benzimidazole functional groups can improve the hydroxide conductivity of the composite ion-solvating membrane. Meanwhile, the in-situ generation of benzimidazole-based covalent organic framework fillers in the membrane can endow it with good compatibility and uniformity with the polybenzimidazole matrix, as well as enhanced mechanical properties of the membrane. In the present invention, there are abundant ion transport sites both on the sulfonated polybenzimidazole and the benzimidazole covalent organic framework, and the grid structure of the covalent organic framework can effectively control the dimensional stability of the membrane material. The preparation method is simple, controllable, and easy to scale up. The composite alkaline ion-solvating membrane material prepared by the present invention has good application prospects in energy conversion fields such as alkaline electrolyzed water, zinc-air batteries, carbon dioxide electroreduction, and ammonia fuel cells.

[0024] Preferably, the mass ratio of the total mass of the aryl trialdehyde monomer and the aryl tetramine monomer to the mass of the sulfonated polybenzimidazole is (0.05 - 1):1.

[0025] Preferably, the preparation method of the sulfonated polybenzimidazole is as follows: 3,3,4,4-diaminobenzidine is mixed with polyphosphoric acid, and a dicarboxylic acid monomer containing SAr 1 and Ar 2 structures is added. The reaction is carried out at 100 - 220 °C for 12 - 48 h. After washing with saturated sodium bicarbonate solution and water until neutral, it is dried to obtain the sulfonated polybenzimidazole.

[0026] Preferably, in the preparation method of the sulfonated polybenzimidazole, the total molar amount of the dicarboxylic acid monomer containing SAr 1 and Ar 2 structures and the molar ratio of 3,3,4,4-diaminobenzidine is 1:1.

[0027] Preferably, in the preparation method of the sulfonated polybenzimidazole, the drying is vacuum drying, the temperature of the vacuum drying is 60 - 100 °C, and the time is 12 - 24 h.

[0028] More preferably, the preparation method of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion-solvating membrane includes the following steps:

[0029] 3,3,4,4-diaminobenzidine or 1,2,4,5-benzenetetramine is mixed with polyphosphoric acid, and a dicarboxylic acid monomer containing SAr 1 and Ar 2The dicarboxylic acid monomer of the structure reacts at 100-220 °C for 12-48 h. After washing with saturated sodium bicarbonate solution and water until neutral, it is dried to obtain the sulfonated polybenzimidazole;

[0030] Dissolve the sulfonated polybenzimidazole in a polar solvent to obtain a first solution, dissolve the aryltetraamine monomer in a polar solvent to obtain a second solution, then mix the first solution and the second solution to obtain solution ①. Dissolve the aryltrialdehyde monomer in a polar solvent to obtain solution ②, and add solution ② dropwise into solution ① and stir until fully mixed to obtain a casting solution. The casting solution is prepared into a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane by thermally induced solvent evaporation;

[0031] Immerse the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in an alkali solution, and after immersion, obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvent membrane.

[0032] Preferably, the polar solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0033] Preferably, the alkali solution includes one of potassium hydroxide solution, potassium carbonate solution, potassium bicarbonate solution, sodium hydroxide solution, sodium carbonate solution, and sodium bicarbonate solution.

[0034] More preferably, the concentration of the alkali solution is 1-15 mol / L.

[0035] Preferably, the immersion temperature of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in the alkali solution is 50-80 °C, and the time is 72-100 h.

[0036] Preferably, the solid content of the casting solution is 3-5 wt.%.

[0037] Preferably, the process of preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane by thermally induced solvent evaporation is as follows: pour the mixed casting solution into a glass plate mold, and the ratio of the total mass of all polymers in the casting solution to the mold area is 0.5 g / 25 cm 2 , then react at 60 °C for 24 h first, then react at 80 °C for 12-24 h, and finally react at 100 °C for 12-24 h to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane.

[0038] The third technical solution of the present invention:

[0039] The present invention also provides the application of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane in the field of energy conversion technologies, including the fields of alkaline water electrolysis, fuel cells, electroreduction of carbon dioxide, or zinc-air batteries.

[0040] Compared with the prior art, the present invention has the following advantages and technical effects:

[0041] (1) For the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane of the present invention, the main structural units are all benzimidazole, and the polymer transitions from linear to grid ultra-high crosslinking. The membrane is homogeneous, transparent, and has strong compatibility.

[0042] (2) For the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane of the present invention, sulfonic acid groups are introduced into the molecular chains of polybenzimidazole, which can increase the ion transport sites and greatly improve the ionic conductivity of the ion solvent membrane material in low-concentration alkaline solutions.

[0043] (3) For the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane of the present invention, a covalent organic framework (COF) with highly ordered sub-nanoscale pores and dimensional stability is introduced, which can control the water absorption and swelling rate of the composite membrane.

[0044] (4) The preparation method of the present invention is simple and efficient. At the same time, the alkaline ion solvent composite membrane material prepared by the present invention can be applied not only in alkaline electrolyzers but also extended to other energy conversion technology fields such as fuel cells, electroreduction of carbon dioxide, and zinc-air batteries, and has considerable application prospects. Description of the Drawings

[0045] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0046] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of sulfonated polybenzimidazole SNPBI-20% prepared in Example 1 of the present invention;

[0047] Figure 2 is the scanning electron microscope image of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane prepared in Example 1 of the present invention;

[0048] Figure 3 is the scanning electron microscope image of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane prepared in Example 2 of the present invention;

[0049] Figure 41H NMR spectrum of sulfonated polybenzimidazole SNPBI-60% prepared in Example 6 of the present invention 1 1H NMR

[0050] Figure 5 1H NMR spectrum of sulfonated polybenzimidazole SPBI-20% prepared in Example 7 of the present invention

[0051] Figure 6 1H NMR spectrum of sulfonated polybenzimidazole SPBI-60% prepared in Example 11 of the present invention

[0052] Figure 7 Polarization curves of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membranes prepared in Examples 1 to 7 of the present invention on an alkaline water electrolysis device Detailed Description of the Invention

[0053] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be construed as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention

[0054] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range

[0055] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail

[0056] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are merely exemplary

[0057] The terms "comprising", "including", "having", "containing", etc. used in this article are all open-ended terms, meaning including but not limited to.

[0058] Unless otherwise specified, the room temperature in the present invention is calculated as 25 ± 2 °C.

[0059] All raw materials used in the examples of the present invention are obtained by purchasing commercially.

[0060] The technical solution of the present invention will be further described below through examples.

[0061] Example 1

[0062] A preparation method of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvent membrane:

[0063] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask. After stirring and heating at 80 °C for 2 h in an N 2 atmosphere to remove air bubbles, simultaneously add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.133 g (0.8 mmol) of sodium 2-sulfoterephthalate monohydrate, and 0.864 g (3.2 mmol) of 1,4-naphthalenedicarboxylic acid. Raise the temperature to 100 °C and maintain for 24 h. The reaction solution is viscous. After the reaction is completed, pour the polymerization product into deionized water while it is hot for filtration, then wash it with saturated sodium bicarbonate solution and deionized water until neutral, and then dry it at 80 °C for 12 h to obtain sulfonated polybenzimidazole SNPBI, denoted as SNPBI-20% (sulfonation degree is 20%). The product was 1 characterized by HNMR, and the results are as Figure 1 shown.

[0064] The structural formula of the prepared sulfonated polybenzimidazole is as follows:

[0065]

[0066] (2) Dissolve 0.0625 g of SNPBI-20% in dimethyl sulfoxide to prepare a SNPBI-20% solution with a concentration of 3 wt.%. Dissolve 0.0375 g of 3,3,4,4-diaminobenzidine in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%, and then add it to the SNPBI-20% solution. The resulting solution is a mixed solution of aryl tetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Dissolve 0.025 g of 1,3,5-tris(4-formylphenyl)benzene in N-methylpyrrolidone to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 , and then react at 60 °C for 24 h, then at 80 °C for 12 h, and finally at 100 °C for 12 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0067] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0068]

[0069] Scanning electron microscopy was used to analyze the cross-sectional structure of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane, as Figure 2 shown.

[0070] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in 6 mol / L potassium hydroxide (KOH) solution for 72 h at a temperature of 50 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Under the condition of 80 °C, the water absorption and swelling test of the above membrane was carried out, and the water absorption rate was measured to be 11.51%, and the swelling rate was 3.72%. The ion conductivity test of the above membrane was carried out in 6 mol / L KOH solution at 80 °C, and the ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was 235.33 mS / cm.

[0071] Example 2

[0072] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0073] (1) The preparation of sulfonated polybenzimidazole SNPBI is the same as that in Example 1, and the sulfonation degree is the same as that in Example 1.

[0074] (2) Take 0.0625 g of SNPBI - 20% and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Take 0.0375 g of 3,3,4,4 - diaminobenzidine and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Then add it to the sulfonated polybenzimidazole solution. The resulting solution is a mixed solution of aryl tetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Take 0.025 g of 1,3,5 - benzenetricarbaldehyde and dissolve it in N - methylpyrrolidone to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content is 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 12 h, and finally at 100 °C for 20 h to obtain a sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite membrane;

[0075] The structural formula of the sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite membrane is as follows:

[0076]

[0077] Scanning electron microscopy is used to analyze the cross - sectional structure of the sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite membrane, as Figure 3 shown.

[0078] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 8 mol / L for 100 h at a temperature of 60 °C to obtain a sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite alkaline ion solvent membrane. Under the condition of 80 °C, the water absorption and swelling test of the above - mentioned membrane is carried out, and its water absorption rate is measured to be 12.01%, and the swelling rate is 3.78%. The ion conductivity test of the above - mentioned membrane is carried out in a 6 mol / L potassium hydroxide solution at 80 °C. The ion conductivity of the sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite alkaline ion solvent membrane is 256.93 mS / cm.

[0079] Example 3

[0080] Preparation of a sulfonated polybenzimidazole / benzimidazole - based covalent organic framework composite alkaline ion solvent membrane:

[0081] (1) The preparation of sulfonated polybenzimidazole SNPBI is the same as that in Example 1, and the sulfonation degree is the same as that in Example 1.

[0082] (2) Dissolve 0.0625 g of SNPBI-20% in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Dissolve 0.0375 g of 1,2,4,5-benzenetetramine in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Then add it to the sulfonated polybenzimidazole solution. The resulting solution is a mixed solution of aryltetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Dissolve 0.025 g of 1,3,5-trimethyl-2,4,6-benzenetricarbaldehyde in N-methylpyrrolidone to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 18 h, and finally at 100 °C for 18 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0083] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0084]

[0085] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 2 mol / L for 100 h at a temperature of 80 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Under the condition of 80 °C, the water absorption and swelling test of the above membrane was carried out, and its water absorption rate was measured to be 12.47%, and the swelling rate was 4.25%. The ion conductivity test of the above membrane was carried out in a 6 mol / L potassium hydroxide solution at 50 °C. The ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was 228.91 mS / cm.

[0086] Example 4

[0087] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0088] (1) The preparation of sulfonated polybenzimidazole SNPBI is the same as that in Example 1, and the sulfonation degree is the same as that in Example 1.

[0089] (2) Dissolve 0.0625 g of SNPBI (20%) in dimethyl sulfoxide to prepare a solution with a concentration of 4 wt.%. Dissolve 0.0375 g of 1,2,4,5-benzenetetramine in dimethyl sulfoxide to prepare a solution with a concentration of 4 wt.%. Then add it to the sulfonated polybenzimidazole solution to obtain a mixed solution of aryl tetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Dissolve 0.025 g of 1,3,5-trihydroxy-2,4,6-triformylbenzene in N-methylpyrrolidone to prepare a solution with a concentration of 4 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content is 4 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 12 h, and finally at 100 °C for 20 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0090] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0091]

[0092] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 5 mol / L; the immersion time is 80 h and the temperature is 80 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Under the condition of 80 °C, the water absorption and swelling test of the above membrane was carried out, and its water absorption rate was measured to be 12.34%, and the swelling rate was 4.62%. The ion conductivity test of the above membrane was carried out in a 6 mol / L potassium hydroxide solution at 80 °C, and the ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was 218.38 mS / cm.

[0093] Example 5

[0094] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0095] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 80 °C in an atmosphere for 2 h to remove bubbles, and then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.266 g (1.6 mmol) of sodium 2-sulfoterephthalate, and 0.648 g (2.4 mmol) of 1,4-naphthalenedicarboxylic acid simultaneously. Raise the temperature to 180 °C and continue the reaction for 36 h. After the reaction solution becomes viscous, pour the polymerization product into a large amount of deionized water while it is still hot to wash away most of the acid, wash it with saturated sodium bicarbonate solution and deionized water until neutral, and then dry it at 80 °C for 12 h to obtain sulfonated polybenzimidazole SNPBI-40%.

[0096] The structural formula of sulfonated polybenzimidazole is as follows:

[0097]

[0098] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0099] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0100]

[0101] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 10 mol / L; the immersion time is 80 h and the temperature is 60 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Under the condition of 80 °C, the water absorption and swelling test of the above membrane was carried out, and the water absorption rate was measured to be 13.17% and the swelling rate was 4.72%. The ion conductivity test of the membrane was carried out in a 6 mol / L potassium hydroxide solution at 80 °C, and the ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was 246.21 mS / cm.

[0102] Example 6

[0103] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0104] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.399 g (2.4 mmol) of sodium 2-sulfoterephthalate, and 0.432 g (1.6 mmol) of 1,4-naphthalenedicarboxylic acid simultaneously. Raise the temperature to 180 °C and react for 45 h. The reaction solution is viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and dry at 80 °C for 20 h to obtain sulfonated polybenzimidazole SNPBI-60%. The product was 1 characterized by Figure 4 .

[0105] The structural formula of sulfonated polybenzimidazole is as follows:

[0106]

[0107] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 3.

[0108] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0109]

[0110] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 1 mol / L; soak for 80 h at a temperature of 80 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Test the ionic conductivity of the above membrane in a 6 mol / L potassium hydroxide solution at 80 °C. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 258.18 mS / cm.

[0111] Example 7

[0112] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0113] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.133 g (0.8 mmol) of sodium 2-sulfoterephthalate, and 0.532 g (3.2 mmol) of terephthalic acid simultaneously. Raise the temperature to 160 °C and react for 24 h. After the reaction solution becomes viscous, pour the polymerization product into deionized water while it is still hot to wash away most of the acid. Wash with saturated sodium bicarbonate solution and deionized water until neutral, and dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%. The product was 1 characterized by Figure 5 .

[0114] The structural formula of sulfonated polybenzimidazole is as follows:

[0115]

[0116] (2) Dissolve 0.0625 g of SPBI (20%) in dimethyl sulfoxide to prepare a solution with a concentration of 5 wt.%. Dissolve 0.0375 g of 3,3,4,4-diaminobenzidine in dimethyl sulfoxide to prepare a solution with a concentration of 5 wt.%, and then add it to the sulfonated polybenzimidazole solution. The resulting solution is a mixed solution of aryltetramine monomer and sulfonated polybenzimidazole, denoted as solution ①. Dissolve 0.025 g of 1,3,5-tris(4-formylphenyl)benzene in N-methylpyrrolidone to prepare a solution with a concentration of 5 wt.%, denoted as solution ②. Drop solution ② into solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content 5 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 12 h, and finally at 100 °C for 20 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0117] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0118]

[0119] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 6 mol / L; the immersion time is 72 h and the temperature is 60 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was measured at 80 °C in a 6 mol / L potassium hydroxide solution, and the ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane was 250.76 mS / cm.

[0120] Example 8

[0121] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane:

[0122] (1) The preparation of sulfonated polybenzimidazole SPBI was the same as in Example 8, and the sulfonation degree was the same as in Example 8.

[0123] (2) Take 0.0625 g of SPBI-20% and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 4 wt.%. Take 0.0375 g of 3,3,4,4-diaminobenzidine and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 4 wt.%. Then add it to the sulfonated polybenzimidazole solution. The resulting solution is a mixed solution of aryltetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Take 0.025 g of 1,3,5-benzenetricarbaldehyde and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 4 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content 4 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 48 h, and finally at 100 °C for 48 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0124] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0125]

[0126] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 1 mol / L; the immersion time is 100 h and the temperature is 50 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane material. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane was measured in a 6 mol / L potassium hydroxide solution at 80 °C, and the ionic conductivity was 269.93 mS / cm.

[0127] Example 9

[0128] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane:

[0129] (1) The preparation of sulfonated polybenzimidazole SPBI was the same as in Example 8, and the sulfonation degree was the same as in Example 8.

[0130] (2) Dissolve 0.625 g of SPBI-20% in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Dissolve 0.00375 g of dibenzo[b,e][1,4]dioxazine-2,3,7,8-tetraamine in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Then add it to the sulfonated polybenzimidazole solution to obtain a mixed solution of aryl tetraamine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Dissolve 0.0025 g of 2,4,6-tris(4-formylphenyl)-1,3,5-triazine in N-methylpyrrolidone to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained casting solution (solid content is 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, then at 80 °C for 12 h, and finally at 100 °C for 24 h to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane;

[0131] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0132]

[0133] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 10 mol / L; the immersion time is 72 h and the temperature is 50 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Test the ionic conductivity of the above membrane at 80 °C in a 6 mol / L potassium hydroxide solution. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 258.07 mS / cm.

[0134] Example 10

[0135] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane:

[0136] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat in an atmosphere at 100 °C for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.266 g (1.6 mmol) of sodium 2-sulfoterephthalate monosodium salt, and 0.399 g (2.4 mmol) of terephthalic acid simultaneously. Raise the temperature to 200 °C and react for 36 h. After the reaction solution becomes viscous, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-40.

[0137] The structural formula of sulfonated polybenzimidazole is as follows:

[0138]

[0139] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1;

[0140] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0141]

[0142] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 15 mol / L; the immersion time is 72 h and the temperature is 80 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvent membrane. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvent membrane was measured in a 6 mol / L potassium hydroxide solution at 80 °C, and the ionic conductivity was 263.44 mS / cm.

[0143] Example 11

[0144] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvent membrane:

[0145] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, and in an N 2 Stir and heat in an atmosphere at 100 °C for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.399 g (2.4 mmol) of sodium 2-sulfoterephthalate monosodium salt, and 0.266 g (1.6 mmol) of terephthalic acid simultaneously. Raise the temperature to 200 °C and react for 48 h. After the reaction solution becomes viscous, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-60%. The product was1 HNMR characterization is shown in Figure 6 .

[0146] The structural formula of sulfonated polybenzimidazole is as follows:

[0147]

[0148] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as that in Example 10.

[0149] The structural formula of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is as follows:

[0150]

[0151] (3) Immerse the prepared sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane in a potassium hydroxide solution with a concentration of 6 mol / L; the immersion time is 72 h and the temperature is 60 °C, thus obtaining the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane. Conduct an ion conductivity test on the above membrane at 80 °C in a 6 mol / L potassium hydroxide solution. The ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 266.81 mS / cm.

[0152] Example 12

[0153] The preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane includes the following steps:

[0154] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, stir and heat at 100 °C in an N 2 atmosphere for 2 h to remove air bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.922 g (3.438 mmol) of sodium 5-sulfoisophthalate, and 0.864 g (3.2 mmol) of 1,4-naphthalenedicarboxylic acid simultaneously. Set the program for temperature increase, raise the reaction temperature from 100 °C to 200 °C, with a 20 °C increase every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction is completed, quickly pour the polymerization product into deionized water to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0155] The structural formula of sulfonated polybenzimidazole is as follows:

[0156]

[0157] (2) Dissolve 0.0625 g of SPBI-20% in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Dissolve 0.00375 g of 2,3,7,8-phenazine tetramine in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Then add it to the sulfonated polybenzimidazole solution to obtain a mixed solution of aryl tetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Dissolve 0.0025 g of 1,3,5-tris(4-formylstyryl)benzene in N,N-dimethylformamide to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed. Then pour the obtained mixed casting solution (solid content 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, at 80 °C for 12 h, and at 100 °C for 12 h to obtain a benzimidazole-based covalent organic framework composite membrane;

[0158] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0159]

[0160] (3) Immerse the prepared composite membrane material in a sodium hydroxide solution with a concentration of 6 mol / L for 72 h at a temperature of 50 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Test the ionic conductivity of the membrane at 80 °C. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 250.33 mS / cm.

[0161] Example 13

[0162] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane, comprising the following steps:

[0163] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.275 g (0.8 mmol) of sodium 4,4'-biphenyldicarboxylate-3-sulfonate, and 0.666 g (3.2 mmol) of 2,4,6-trimethyl-1,3-benzenedicarboxylic acid simultaneously. Set the program for temperature increase, raise the reaction temperature from 100 °C to 200 °C, increasing the temperature by 20 °C every two hours. When the temperature reaches 200 °C, maintain it for 48 h, and the reaction solution becomes viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash it with saturated sodium bicarbonate solution and deionized water until neutral, and then dry it at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0164] The structural formula of sulfonated polybenzimidazole is as follows:

[0165]

[0166] (2) Take 0.0625 g of SPBI-20% and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%. Take 0.01875 g of 2,3,7,8-phenazine tetramine and dissolve it in dimethyl sulfoxide to prepare a solution with a concentration of 3 wt.%, and then add it to the sulfonated polybenzimidazole solution. The resulting solution is a mixed solution of aryl tetramine monomer and sulfonated polybenzimidazole, denoted as Solution ①. Take 0.0125 g of tris(4-formylphenyl)amine and dissolve it in N,N-dimethylacetamide to prepare a solution with a concentration of 3 wt.%, denoted as Solution ②. Drop Solution ② into Solution ① and stir until fully mixed, then pour the obtained mixed casting solution (solid content is 3 wt.%) into a glass plate mold. The ratio of the total mass of all polymers in the solution to the mold area is 0.5 g / 25 cm 2 . Then react at 60 °C for 24 h, at 80 °C for 12 h, and at 100 °C for 12 h to obtain a benzimidazole-based covalent organic framework composite membrane;

[0167] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0168]

[0169] (3) Immerse the prepared composite membrane material in a potassium carbonate solution with a concentration of 6 mol / L; immerse it for 72 h at a temperature of 50 °C to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Test the ionic conductivity of the membrane at 80 °C. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 236.29 mS / cm.

[0170] Example 14

[0171] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane, comprising the following steps:

[0172] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, stir and heat at 100 °C in an N 2 atmosphere for 2 h to remove air bubbles, then add 0.86 g (4.00 mmol) of 3,3’,4,4’-diaminobenzidine, 0.309 g (0.8 mmol) of 4,4’-(methylenebis(benzene-4,1-diyl))bis(benzoate)-3-sulfonic acid sodium salt, and 0.909 g (3.2 mmol) of 4,4’-(methylenebis(benzene-4,1-diyl))bis(benzoic acid) simultaneously. Set the programmed temperature rise, and the reaction temperature is increased from 100 °C to 200 °C, with a 20 °C increase every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction is completed, pour the polymerization product into a large amount of deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0173] The structural formula of sulfonated polybenzimidazole is as follows:

[0174]

[0175] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0176] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0177]

[0178] (3) Immerse the prepared composite membrane material in a potassium bicarbonate solution with a concentration of 6 mol / L; the immersion time is 72 h and the temperature is 50 °C to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane material. Conduct an ion conductivity test on the membrane at 80 °C, and the ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane is 236.78 mS / cm.

[0179] Example 15

[0180] Preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane, comprising the following steps:

[0181] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, stir and heat at 100 °C in an N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3’,4,4’-diaminobenzidine, 0.395 g (0.8 mmol) of sodium 2,2-bis(4-carboxyphenyl)hexafluoropropanesulfonate, and 1.255 g (3.2 mmol) of 2,2-bis(4-carboxyphenyl)hexafluoropropane simultaneously. Set the program for temperature increase, and the reaction temperature is raised from 100 °C to 200 °C, with a 20 °C increase every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0182] The structural formula of sulfonated polybenzimidazole is as follows:

[0183]

[0184] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0185] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0186]

[0187] (3) Immerse the prepared composite membrane material in a sodium carbonate solution with a concentration of 6 mol / L; the immersion time is 72 h and the temperature is 50 °C to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane material. Test the ionic conductivity of the membrane at 80 °C, and the ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane is 264.79 mS / cm.

[0188] Example 16

[0189] The preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane includes the following steps:

[0190] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove air bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.294 g (0.8 mmol) of sodium 9,10-anthracenedicarboxylate-2-sulfonate, and 1.210 g (3.2 mmol) of 2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4,4'-dicarboxylic acid simultaneously. Set the temperature to rise gradually. The reaction temperature is increased from 100 °C to 200 °C, with a 20 °C increase every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0191] The structural formula of sulfonated polybenzimidazole is as follows:

[0192]

[0193] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0194] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0195]

[0196] (3) Immerse the prepared composite membrane material in a potassium carbonate solution with a concentration of 6 mol / L; soak for 72 h at a temperature of 50 °C to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Conduct an ion conductivity test on the membrane at 80 °C. The ion conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 236.29 mS / cm.

[0197] Example 17

[0198] The preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane includes the following steps:

[0199] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat in an atmosphere at 100 °C for 2 h to remove bubbles, then simultaneously add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.254 g (0.8 mmol) of sodium 2,6-naphthalenedicarboxylate-1-sulfonate, and 1.018 g (3.2 mmol) of 2,5-diphenylterephthalic acid. Set the program for temperature increase, raise the reaction temperature from 100 °C to 200 °C, with a 20 °C increase every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0200] The structural formula of sulfonated polybenzimidazole is as follows:

[0201]

[0202] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0203] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0204]

[0205] (3) Immerse the prepared composite membrane material in a sodium bicarbonate solution with a concentration of 6 mol / L; the immersion time is 72 h and the temperature is 50 °C to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane material. Test the ionic conductivity of the membrane at 80 °C. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane is 252.22 mS / cm.

[0206] Example 18

[0207] The preparation of a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvent membrane includes the following steps:

[0208] (1) Add 50 g of polyphosphoric acid to a 100 mL three-necked flask, in N 2Stir and heat at 100 °C in an atmosphere for 2 h to remove bubbles, then add 0.86 g (4.00 mmol) of 3,3,4,4-diaminobenzidine, 0.254 g (0.8 mmol) of sodium 1,4-naphthalenedicarboxylate-6-sulfonate, and 0.852 g (3.2 mmol) of 9,10-anthracenedicarboxylic acid simultaneously. Set the program for temperature increase, raise the reaction temperature from 100 °C to 200 °C, increasing by 20 °C every two hours. When the temperature reaches 200 °C, maintain for 48 h, and the reaction solution becomes viscous. After the reaction, pour the polymerization product into deionized water while it is still hot to wash away most of the acid, wash with saturated sodium bicarbonate solution and deionized water until neutral, and then dry at 80 °C for 12 h to obtain sulfonated polybenzimidazole SPBI-20%.

[0209] The structural formula of sulfonated polybenzimidazole is as follows:

[0210]

[0211] (2) The preparation of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is the same as in Example 1.

[0212] The structural formula of the benzimidazole-based covalent organic framework composite membrane is as follows:

[0213]

[0214] (3) Immerse the prepared composite membrane material in a potassium hydroxide solution with a concentration of 6 mol / L; soak for 72 h at a temperature of 50 °C to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane material. Test the ionic conductivity of the membrane at 80 °C. The ionic conductivity of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane is 253.33 mS / cm.

[0215] Figure 7 This is the polarization curve (60 °C, 6 mol / L KOH solution) of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane prepared in Examples 1 to 7 of the present invention on an alkaline water electrolysis device.

[0216] Use the film tensile test method (refer to GB 13022-1991) to measure the mechanical properties of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ionic solvation membrane prepared in Examples 1 to 18 of the present invention. The results are shown in Table 1.

[0217] Table 1

[0218]

[0219]

[0220] Note: In the above tests, the water absorption rate and swelling rate of the membrane were tested according to GB / T 20042.3-2022; the conductivity was measured by a two-electrode method using an electrochemical workstation (Bio-Logic VSP-300).

[0221] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the technical field of the present application within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane, characterized in that: Prepared from sulfonated polybenzimidazole and benzimidazole-based covalent organic framework; The structural formula of the sulfonated polybenzimidazole is shown in formula (1): Wherein, x represents the degree of sulfonation, 0<x≤80; SAr1 is any one of the following structural units: Ar2 is any one of the following structural units: The benzimidazole-based covalent organic framework is synthesized from an aromatic trialdehyde monomer and an aromatic tetraamine monomer, wherein the aromatic trialdehyde monomer is any one of the following structures: The aromatic tetraamine monomer is any one of the following structures:

2. A method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 1, characterized in that: Sulfonated polybenzimidazole is prepared by polymerization reaction, and aromatic trialdehyde monomer and aromatic tetraamine monomer are added to the sulfonated polybenzimidazole solution to obtain a casting solution. The casting solution is subjected to heat-induced solvent evaporation to prepare a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane, and the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is subjected to alkali treatment to obtain the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane.

3. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 2, characterized in that: The mass ratio of the total mass of the aromatic trialdehyde monomer and the aromatic tetraamine monomer to the mass of the sulfonated polybenzimidazole is (0.05-1):

1.

4. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 2, characterized in that: The preparation method of the sulfonated polybenzimidazole is as follows: 3,3,4,4-diaminobenzidine or 1,2,4,5-phenyltetramine is mixed with polyphosphoric acid, a dicarboxylic acid monomer containing SA1 and Ar2 structures is added, the mixture is reacted at 100 to 220° C. for 12 to 48 hours, the mixture is washed with a saturated sodium bicarbonate solution and water until neutral, and then dried to obtain the sulfonated polybenzimidazole.

5. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 4, characterized in that: The molar ratio of the total molar amount of the dicarboxylic acid monomers containing the SA1 and Ar2 structures to 3,3,4,4-diaminobenzidine is 1:(1-1.5).

6. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 4, characterized in that: The drying is vacuum drying, the temperature of the vacuum drying is 60-100° C., and the time is 12-24 hours.

7. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 2, characterized in that: The following steps are involved: Mixing 3,3,4,4-diaminobenzidine and polyphosphoric acid, adding dicarboxylic acid monomers containing SAr1 and Ar2 structures, reacting at 100 to 220° C. for 12 to 48 hours, washing with saturated sodium bicarbonate solution and water until neutral, and drying to obtain the sulfonated polybenzimidazole; The sulfonated polybenzimidazole is dissolved in a polar solvent to obtain a first solution, an aromatic tetraamine monomer is dissolved in a polar solvent to obtain a second solution, and then the first solution and the second solution are mixed to obtain a solution ①, an aromatic trialdehyde monomer is dissolved in a polar solvent to obtain a solution ②, and the solution ② is added dropwise into the solution ①, and stirred until fully mixed to obtain a casting solution, and the casting solution is prepared by heat-induced solvent evaporation to obtain a sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane; The sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite membrane is immersed in an alkaline solution, and after the immersion is completed, the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane is obtained.

8. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 7, characterized in that: The polar solvent includes at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.

9. The method for preparing the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 7, characterized in that: The alkaline solution includes one of potassium hydroxide solution, potassium carbonate solution, potassium bicarbonate solution, sodium hydroxide solution, sodium carbonate solution and sodium bicarbonate solution.

10. Application of the sulfonated polybenzimidazole / benzimidazole-based covalent organic framework composite alkaline ion solvation membrane according to claim 1 in the field of energy conversion technology, characterized in that: Including the fields of alkaline water electrolysis, fuel cells, carbon dioxide electroreduction or zinc-air batteries.

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