Ion solvation membrane as well as preparation method and application thereof

Abstract

The invention provides an ion solvated membrane and a preparation method and application thereof.The ion solvated membrane comprises at least one of branched polyaryloxyindole and side-chain polyaryloxyindole, the branched polyaryloxyindole comprises at least one of a compound A1, a compound A2 and a compound A3, and the side-chain polyaryloxyindole comprises at least one of side-chain polyaryloxyindole and side-chain polyaryloxyindole. The structure of the side-chain type polyarylene oxoindole is as shown in a compound B; the compound A1 comprises a plurality of first chain segments and a plurality of second chain segments, the compound A2 comprises a plurality of first chain segments and a plurality of third chain segments, the compound A3 comprises a plurality of first chain segments, a plurality of second chain segments and a plurality of third chain segments, a is the number of side chain carbon atoms, and M is an aromatic unit; ar1 is a monomer having a first number of branching points, Ar2 is a monomer having a second number of branching points, and M is different from Ar1 and Ar2. The membrane effectively solves the problems of short operation life and poorer electrochemical performance of the existing ion solvation membrane.

Description

Technical Field

[0001] This application provides an ion-solventized film, its preparation method, and its application, belonging to the field of materials chemistry. Background Technology

[0002] As a key component of the electrolyzer, the diaphragm determines the efficiency and safety of the hydrogen production process through water electrolysis, and is crucial to the electrolyzer product. Looking at current alkaline electrolyzer diaphragm products, traditional composite diaphragms offer good alkali resistance but pose a risk of gas interpermeation; anion exchange membranes (AEMs) have high ionic conductivity and low gas permeability, but their cationic functional groups have poor stability, potentially limiting their service life.

[0003] Ion solvating membranes (ISMs) are still in the research and development stage, with few mature commercial products. Commonly used ISMs on the market mainly include polybenzimidazole (PBI), polyvinyl alcohol (PVA), polyethylene glycol (PEO), imidazole-containing polymers, and polyarylene-oxindole (PAO). Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide an ion solvation membrane, its preparation method and application, so as to solve the above-mentioned problems existing in the prior art.

[0005] According to some embodiments of this application, one embodiment of this application provides an ion solvation membrane, comprising at least one of branched polyarylene oxyindole and side-chain polyarylene oxyindole, wherein the branched polyarylene oxyindole comprises at least one of compound A1, compound A2, and compound A3, and the structure of the side-chain polyarylene oxyindole is as shown in compound B: The compound A1 comprises several first segments. and several second chain segments The compound A2 comprises several first segments. and several third chain segments The compound A3 comprises several first segments. Several second chain segments and several third chain segments Where a is the number of carbon atoms in the side chain, M is the aromatic unit; Ar1 ​​is a monomer with the first number of branching points, Ar2 is a monomer with the second number of branching points, and M is different from both Ar1 and Ar2.

[0006] In some embodiments, the structural formula of compound A1 is: The structural formula of compound A2 is: The structural formula of compound A3 is: .

[0007] In some embodiments, M comprises at least one of the following compounds: .

[0008] In some embodiments, the first quantity is 3, and Ar1 comprises at least one of the following compounds: .

[0009] In some embodiments, the second quantity is 4, and Ar2 comprises at least one of the following compounds: , , .

[0010] In some embodiments, n is an integer from 100 to 5000, and m is an integer from 10 to 1000. l The value is an integer from 10 to 1000. Accordingly, the weight-average molecular weight of compound A1 is 3000 to 1800000, the weight-average molecular weight of compound A2 is 3000 to 1800000, the weight-average molecular weight of compound A3 is 3000 to 1800000, and the weight-average molecular weight of compound B is 3000 to 1800000, where 1 ≤ a ≤ 20.

[0011] In some embodiments, 1 ≤ a ≤ 10.

[0012] In some embodiments, the method for preparing the branched polyaryleneoxyindole includes: Indigo, compound M, and compound Ar1 are dissolved in a first organic solvent, and an acid catalyst is added at -10℃ to 0℃ to carry out the reaction, yielding the branched polyarylethenoyloxyindole shown in compound A1; or... Indigo, compound M, and compound Ar2 were dissolved in a first organic solvent, and an acid catalyst was added at -10℃ to 0℃ to carry out the reaction, yielding the branched polyaryleneoxyindole shown in compound A2.

[0013] Indigo, compound M, compound Ar1, and compound Ar2 were dissolved in a first organic solvent, and an acid catalyst was added at -10℃ to 0℃ to carry out the reaction, yielding the branched polyaryleneoxyindole shown in compound A3.

[0014] In some embodiments, in the preparation of the branched polyarylene oxygen indole represented by compound A1, the molar ratio of indigo to compound M is 1:(0.5~2.5), and the molar ratio of indigo to compound Ar1 is 1:(0.0005~0.5).

[0015] In some embodiments, in the preparation of the branched polyarylene oxygen indole represented by compound A2, the molar ratio of indigo to compound M is 1:(0.5~2.5), and the molar ratio of indigo to compound Ar1 is 1:(0.0005~0.5).

[0016] In some embodiments, in the preparation of the branched polyarylene oxygen indole represented by compound A3, the molar ratio of indigo to compound M is 1:(0.5~2.5), the molar ratio of indigo to compound Ar1 is 1:(0.0005~0.5), and the molar ratio of indigo to compound Ar2 is 1:(0.0005~0.5).

[0017] In some embodiments, the method for preparing the side-chain polyaryleneoxyindole includes: Indigo and compound M are dissolved in a first organic solvent, and an acid catalyst is added at -10°C to 0°C to carry out the reaction, yielding polyaryletheneoxyindole; or... The polyarylene oxyindole and bromool were dissolved in an organic solvent and reacted under alkaline conditions at 75°C to 85°C to obtain side-chain polyarylene oxyindole.

[0018] In some embodiments, the molar ratio of indigo to compound M is 1:(0.5~2.5).

[0019] In some embodiments, the acid catalyst includes at least one of trifluoromethanesulfonic acid and trifluoroacetic acid.

[0020] In some embodiments, the first organic solvent includes at least one of dichloromethane and chloroform.

[0021] According to some embodiments of this application, one aspect of this application provides a method for preparing an ion-solvated film as described in any of the above embodiments, comprising: The branched polyaryleneoxyindole is dissolved in a second organic solvent to obtain a first film-forming solution. The first film-forming solution is then used to form a film to obtain an ion-solventized film; or... The side-chain polyaryleneoxyindole is dissolved in a second organic solvent to obtain a second film-forming solution. The second film-forming solution is then used to form a film to obtain an ion-solventized film; or... The branched polyarylene oxyindole and the side-chain polyarylene oxyindole are dissolved in a second organic solvent to obtain a branched polyarylene oxyindole solution and a side-chain polyarylene oxyindole solution, respectively. The branched polyarylene oxyindole solution and the side-chain polyarylene oxyindole solution are mixed to obtain a third film-forming solution. The third film-forming solution is used to form a film to obtain an ion-solventized film.

[0022] In some embodiments, the film is formed by coating.

[0023] In some embodiments, the coating temperature is 50°C to 90°C.

[0024] In some embodiments, the second organic solvent includes at least one of N-methylpyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, and dimethyl sulfoxide.

[0025] In some embodiments, the solid content of the first film-forming liquid, the second film-forming liquid, and the third film-forming liquid is 10% to 35%.

[0026] According to some embodiments of this application, another aspect of this application provides the use of the ion solvation membrane as described in the above embodiments in hydrogen production by water electrolysis.

[0027] According to some embodiments of this application, another aspect of this application provides an alkaline electrolytic cell, including an ion-solvation membrane as described in any one of the above embodiments or an ion-solvation membrane obtained by any one of the above embodiments.

[0028] Compared with the prior art, this application has the following beneficial effects: This application utilizes branched polymers to prepare and obtain ion-solubilized membranes (ISMs) exhibiting good mechanical properties, alkali-absorbing stability, and excellent electrochemical performance. Specifically, branched polyaryleneoxyindole, with its stable intrinsic structure and a certain degree of branching, ensures the membrane's chemical stability and mechanical properties. Furthermore, the addition of side-chain polyaryleneoxyindole to the branched polyaryleneoxyindole enhances the hydrophilicity and alkali-absorbing capacity of the ISM, thereby further reducing the sheet resistance of the ion-solubilized membrane and effectively lowering the voltage during alkaline water electrolysis.

[0029] This type of membrane effectively solves the problems of low service life and poor electrochemical performance of current ISMs, and shows great promise in alkaline water electrolysis applications. Attached Figure Description

[0030] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0031] Figure 1 This is a polarization curve of the alkaline electrolyzer for the ion-solventized membrane prepared in Example 1 of this application; Figure 2 This is a polarization curve of the alkaline electrolyzer for the ion-solventized membrane prepared in Example 2 of this application; Figure 3 This is a polarization curve of the alkaline electrolyzer for the ion-solventized membrane prepared in Example 3 of this application; Figure 4 This is a polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Example 4 of this application; Figure 5 This is a polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Example 5 of this application; Figure 6 The image shows the polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Comparative Example 1 of this application. Figure 7 The image shows the polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Comparative Example 2 of this application. Figure 8 The image shows the polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Comparative Example 3 of this application. Figure 9 The image shows the polarization curve of the alkaline electrolytic cell for the ion-solventized membrane prepared in Comparative Example 4 of this application. Figure 10 This is a polarization curve of the alkaline electrolyzer for the ion-solventized membrane prepared in Comparative Example 5 of this application. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0033] Example 1 This embodiment provides a method for preparing an ion-solvated film, which specifically includes the following steps: (1) Add 10g indigo, 8g fluorene, and 0.5g triptene to 30mL of dichloromethane and mix thoroughly by mechanical stirring at -10℃. Then, add 15mL of trifluoroacetic acid and 40mL of trifluoromethanesulfonic acid dropwise for reaction. After 5 hours, pour the reaction solution into methanol to precipitate the crude product. Wash the crude product repeatedly with 1M KOH solution and deionized water, and dry the product to obtain the branched polyaryleneoxyindole as shown in compound A1-1, with a weight-average molecular weight M. w =63200, number-average molecular weight M n =34871, PDI (Polymer Dispersion Index) = 1.81,

[0034] A1-1; 10g indigo, 8g biphenyl, and 1.5g spirofluorene were added to 30mL of dichloromethane and then mechanically stirred at -10℃ until homogeneous. Then, 15mL of trifluoroacetic acid and 40mL of trifluoromethanesulfonic acid were added dropwise to react. After 4 hours, the reaction solution was poured into methanol to precipitate the crude product. The crude product was repeatedly washed with 1M KOH solution and deionized water, and then dried to obtain the branched polyaryleneoxyindole as shown in compound A2-1, with a weight-average molecular weight M. w =51382, number-average molecular weight M n =29851, PDI=1.72, ; 10g of indigo and 8g of fluorene were added to 30mL of dichloromethane and mechanically stirred at -10℃ until homogeneous. Then, 15mL of trifluoroacetic acid and 40mL of trifluoromethanesulfonic acid were added dropwise for reaction. After 3 hours, the reaction solution was poured into methanol to precipitate the polymer. The polymer was repeatedly washed with 1M KOH solution and deionized water, and the product was dried to obtain polyoxyindofluorene. 1g of dried polyoxyindofluorene and 1.5g of 6-bromo-1-hexanol were dissolved in 20mL of DMSO, and 3g of K2CO3 were added. The mixture was reacted at 80℃ for 48 hours. The product was precipitated with deionized water, repeatedly washed, and dried to obtain the side-chain polyaryleneoxyindofluorene as shown in compound B, with a weight-average molecular weight M. w =37658, number-average molecular weight M n =22638, PDI=1.66: ; (2) The dried compounds A1-1, A2-1 and B were dissolved in N-methylpyrrolidone to prepare a polymer solution with a solid content of 15%. The polymer solutions (compounds A1-1, A2-1 and B) were mixed in a ratio of 1:1:1 to obtain a uniform dispersion. The dispersion was then coated at 50°C using a scraping platform to prepare an ion-solventized film of the polymer blend.

[0035] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this embodiment are shown in Table 1. The polarization curves of the above ion-solventized membrane in an alkaline electrolyzer at 60°C and 30 wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 1. Figure 1 As shown.

[0036] Example 2 This embodiment provides a method for preparing an ion-solvated film, which specifically includes the following steps: (1) Add 10g indigo, 10g biphenyl, and 0.5g triptene to 30mL of dichloromethane and mix thoroughly by mechanical stirring at -10℃. Then add 15mL trifluoroacetic acid and 40mL trifluoromethanesulfonic acid dropwise for reaction. After 5 hours, pour the reaction solution into methanol to precipitate the polymer. After repeatedly washing the polymer with 1M KOH solution and deionized water, dry the product to obtain the branched polyaryleneoxyindole as shown in compound A1-2, with a weight-average molecular weight M. w =72362, number-average molecular weight M n =31234, PDI=2.32,

[0037] A1-2; (2) The dried compound A1-2 was dissolved in N,N'-dimethylacetamide to prepare a polymer solution with a solid content of 30%. After obtaining a uniform dispersion, the solution was coated at 80°C using a scraping platform to prepare an ion-solventized film.

[0038] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this embodiment are shown in Table 1. The polarization curves of the above ion-solventized membrane in an alkaline electrolyzer at 60°C and 30 wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 1. Figure 2 As shown.

[0039] Example 3 This embodiment provides a method for preparing an ion-solvated film, which specifically includes the following steps: (1) 10g indigo, 11g p-terphenyl, and 1g pyrene were added to 30mL of dichloromethane and then mechanically stirred at -10℃ until homogeneous. Then, 15mL of trifluoroacetic acid and 40mL of trifluoromethanesulfonic acid were added dropwise for reaction. After 4 hours, the reaction solution was poured into methanol to precipitate the polymer. The polymer was repeatedly washed with 1M KOH solution and deionized water, and the product was dried to obtain the branched polyaryleneoxyindole as shown in compound A2-2, with a weight-average molecular weight M. w =81457, number-average molecular weight M n =29700, PDI=2.74, ; (2) The dried compound A2-2 was dissolved in N,N'-dimethylformamide to prepare a polymer solution with a solid content of 20%. After obtaining a uniform dispersion, the solution was coated at 60°C using a scraping platform to prepare an ion-solventized film.

[0040] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this embodiment are shown in Table 1. The polarization curves of the above ion-solventized membrane in an alkaline electrolyzer at 60°C and 30 wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 1. Figure 3 As shown.

[0041] Example 4 This embodiment provides a method for preparing an ion-solvated film, which specifically includes the following steps: (1) Add 10g indigo and 10g fluorene to 30mL dichloromethane and mix thoroughly by mechanical stirring at -10℃. Then add 15mL trifluoroacetic acid and 40mL trifluoromethanesulfonic acid dropwise for reaction. After 3 hours, pour the reaction solution into methanol to precipitate the polymer. Wash the polymer repeatedly with 1M KOH solution and deionized water, and dry the product to obtain polyoxyindofluorene. Dissolve 1g of dried polyoxyindofluorene and 1.5g of 6-bromo-1-hexanol in 20mL DMSO, add 3g K2CO3, and react at 80℃ for 48 hours. Precipitate the product with deionized water, wash repeatedly, and dry to obtain the side-chain polyaryleneoxyindofluorene as shown in compound B, with a weight-average molecular weight M. w =42766, number-average molecular weight M n =22548, PDI=1.90: ; (2) The dried compound was dissolved and prepared into a polymer solution with a solid content of 20% using N,N'-dimethylformamide. After obtaining a uniform dispersion, the solution was coated at 80°C using a scraping platform to prepare an ion-solventized film.

[0042] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this embodiment are shown in Table 1. The polarization curves of the above ion-solventized membrane in an alkaline electrolyzer at 60°C and 30 wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 1. Figure 4 As shown.

[0043] Example 5 This embodiment provides a method for preparing an ion-solvated film, which specifically includes the following steps: (1) 10g indigo, 4g biphenyl, 5g fluorene, 1g spirodifluorene, and 0.5g triptene were added to 30mL of dichloromethane and then mechanically stirred at -10℃ until homogeneous. Then, 15mL of trifluoroacetic acid and 40mL of trifluoromethanesulfonic acid were added dropwise for reaction. After 3.5 hours, the reaction solution was poured into methanol to precipitate the polymer. The polymer was repeatedly washed with 1M KOH solution and deionized water, and the product was dried to obtain the branched polyaryleneoxyindole as shown in compound A3-1, with a weight-average molecular weight M. w =52347, number-average molecular weight M n =19766, PDI=2.65, ; (2) The dried compound A3-1 was dissolved in N,N'-dimethylformamide to prepare a polymer solution with a solid content of 26%. After obtaining a uniform dispersion, the solution was coated at 70°C using a scraping platform to prepare an ion-solventized film.

[0044] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this embodiment are shown in Table 1. The polarization curves of the above ion-solventized membrane in an alkaline electrolyzer at 60°C and 30 wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 1. Figure 5 As shown.

[0045] Table 1

[0046] Comparative Example 1 The only difference between this comparative example and Example 1 is that the polymer solution used for coating is prepared from A1-1:A2-1:B in a ratio of 1:1:8. As shown in Table 2, changing the composition of the polymer blend increases the swelling of the ion-solventized film, correspondingly reducing its strength and increasing its sheet resistance. The polarization curves also show a certain decrease in the film's electrochemical performance.

[0047] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this comparative example are shown in Table 2. The polarization curves of the above ion-solventized membranes in an alkaline electrolyzer at 60℃ and 30wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 2. Figure 6 As shown.

[0048] Comparative Example 2 The only difference between this comparative example and Example 2 is that the amount of tripterene used is 1g. The increase in the amount of tripterene has little effect on the mechanical strength of the membrane; however, the membrane swells more in the alkaline solution, and its surface resistance also increases, resulting in a certain decrease in the electrochemical performance shown by the polarization curve of the alkaline electrolytic cell.

[0049] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this comparative example are shown in Table 2. The polarization curves of the above ion-solventized membranes in an alkaline electrolyzer at 60℃ and 30wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 2. Figure 7 As shown.

[0050] Comparative Example 3 The only difference between this comparative example and Example 3 is that monomer M is replaced with o-terphenyl instead of p-terphenyl, resulting in a branched polyarylene oxyindole with a weight-average molecular weight M. w =78954, number-average molecular weight M n =27609, PDI=2.86. Changing the configuration of monomer M has a certain impact on the strength and swelling of the membrane, the sheet resistivity of the membrane increases slightly, and the electrochemical performance decreases to a certain extent.

[0051] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this comparative example are shown in Table 2. The polarization curves of the above ion-solventized membranes in an alkaline electrolyzer at 60℃ and 30wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 2. Figure 8 As shown.

[0052] Comparative Example 4 The only difference between this comparative example and Example 4 is that the reaction time was adjusted to 1.5 hours. After 1.5 hours of reaction, the reaction solution was poured into methanol to precipitate the polymer. After adjusting the reaction time, the molecular weight of the polymer was significantly reduced, and the weight-average molecular weight M... w =16211, number-average molecular weight M n =10032, PDI=1.62. The membrane strength is significantly lower than that of the previous example, the swelling ratio is somewhat increased, the sheet resistance is increased, and the electrochemical performance of the membrane is reduced.

[0053] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this comparative example are shown in Table 2. The polarization curves of the above ion-solventized membranes in an alkaline electrolyzer at 60℃ and 30wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 2. Figure 9 As shown.

[0054] Comparative Example 5 The only difference between this comparative example and Example 5 is that the coating temperature was changed to 40°C. After changing the coating temperature during film formation, the film strength decreased, the sheet resistance increased to a certain extent, and the electrochemical performance of the film decreased.

[0055] The thickness, strength, swelling, and sheet resistivity of the branched polymer ion-solventized membrane prepared in this comparative example are shown in Table 2. The polarization curves of the above ion-solventized membranes in an alkaline electrolyzer at 60℃ and 30wt% KOH, combined with a commercial non-precious catalyst, are shown in Table 2. Figure 10 As shown.

[0056] Table 2

[0057] The detection methods for each indicator in Tables 1 and 2 are as follows: 1. Membrane thickness measurement: After the prepared ion-solventized membrane is completely dried in a 60℃ oven, the thickness is measured at 5 points in different areas of the sample using a micrometer to obtain the average thickness.

[0058] 2. Strength and Elongation at Break Measurement: The tensile strength of the membrane is tested using a universal testing machine. The test fixture should not cause the specimen to break at the fixture. When applying load, the longitudinal axis of the specimen should coincide with the tensile direction passing through the center line of the fixture. Prepare the samples by cutting them into strips of a specific size according to the method specified in GB / T1040.3—2006. The edges of the samples should be smooth and without gaps. Prepare three or more samples. Measure the dimensions of the samples. The thickness and width of each sample should be measured at three points within the gauge length, and the average value should be taken. The accuracy of the thickness measurement is ±0.2%, and the accuracy of the width measurement is ±0.5%. After preparing the samples, place them in the test fixture, aligning the longitudinal axis of the sample with the line connecting the centers of the upper and lower fixtures, and clamp them tightly. Determine the width and thickness of the sample, and test the tensile strength of the sample at a fixed tensile speed. After the experiment, the tensile strength of the membrane is calculated based on the tensile stress-strain curve and the initial thickness and width data of the membrane sample: σ = F / (b × d), where σ is the maximum tensile strength of the membrane (MPa), F is the maximum load (N), b is the sample width (mm), and d is the sample thickness (mm). The final result should be the average value calculated from three or more samples.

[0059] 3. Swelling Rate Measurement: Swelling rate is one of the standards for measuring the dimensional stability of the membrane and affects its mechanical properties. When testing the swelling rate, considering the potential anisotropy of the sample, strips of length × width = 40mm × 20mm are cut parallel to the membrane roll axis as test strips for the transverse dimensional change rate (long side parallel to the membrane roll axis); strips of length × width = 40mm × 20mm are cut perpendicular to the membrane roll axis as test strips for the longitudinal dimensional change rate (long side perpendicular to the membrane roll axis). At least three samples are required, and they must be free of wrinkles, defects, and breakage. The samples are placed in an oven and dried at 60℃ for 24 hours, then cooled to room temperature. The initial length L0 and initial width W0 of the sample are measured with calipers, and the thickness d0 is measured with a micrometer. Depending on the specific sample, the sample may be immersed in a 30% KOH solution at 80℃ for 24 hours or more. After removing the sample, lay it flat on the measuring platform, measure its length L1 and width W1, measure its thickness d1 with a micrometer, and calculate the swelling ratio of the sample: Δ L= ( L 1 -L 0) / L 0×100%, Δ W= (W1 -W 0) / W 0×100%, Δ d= ( d 1 -d 0) / d 0×100%.

[0060] 4. Sheet Resistance Measurement: Sheet resistance reflects the conductivity of the membrane in the electrolyte solution, measured in Ω·cm². The method used is AC impedance spectroscopy, which utilizes a resistance meter to measure the impedance of the platinum sheet-KOH-immersed diaphragm-platinum sheet electrochemical system at high frequencies (1000Hz or higher). The sample diaphragm is cut to fit the fixture size; three or more samples are required, and each sample must be marked. When assembling the samples on the fixture, a torque wrench is used to tighten the bolts to a fixed torque. During testing, the platinum electrode must be completely immersed in the KOH solution; the KOH solution must be replaced after each test to maintain its concentration. Furthermore, temperature has a significant impact on the test results; the temperature can be controlled using a heated magnetic stirrer for each test. The CorrTest electrochemical testing system is used to test the sheet resistance. After assembling the fixture, the electrochemical workstation is turned on, and the AC impedance-impedance-frequency scan method is selected. The impedance frequency range is 1 Hz to 1 × 10⁻⁶. 6 Hz. The impedance value R of the sample can be read from the intersection of the high-frequency part of the spectrum with the real axis after obtaining the impedance spectrum. To eliminate system impedance, the resistances of the n-piece diaphragm system and the n+1-piece diaphragm system (where the n+1-th diaphragm is the same as the previous n diaphragm systems) are measured separately. The difference between the two is the resistance of the n+1-th diaphragm in the two diaphragm systems. Finally, the surface resistance is calculated using the effective area (A): S = (S n+1 -S n ) mΩ, R=S×A×0.001Ω·cm 2 Where S n The resistance reading is S when there are n diaphragms. n+1 The resistance reading is for a system with n+1 diaphragm sheets, where A is the effective area.

[0061] 5. Electrolytic Cell Polarization Curve Test: Before the test, prepare the equipment, including electrolytic cell fixtures, gaskets, water bath, electrochemical workstation, current amplifier, torque wrench, necessary alkali solution, and related accessories. Assemble the electrolytic cell. The ion-solvation membrane should be pretreated before assembly to ensure complete swelling in the corresponding alkali solution at the operating temperature, preventing swelling in the electrolytic cell after assembly. Electrolytic cell assembly has a certain impact on the final electrolysis effect. During assembly, it is necessary to maintain consistency in the operating steps, fix the material and thickness of the gaskets, and use a torque wrench to tighten the fixtures, ensuring consistent tightness for each experiment. After completing the electrolytic cell assembly, use a multimeter or ohmmeter to measure the resistance between the two sides of the electrolytic cell fixture to confirm that there are no short circuits caused by membrane damage or assembly errors. After assembly, adjust the diaphragm pump / peristaltic pump to start the alkali solution circulation. It is important to note that for each experiment, the concentration and conductivity of the alkali solution must meet the experimental requirements, and the alkali solution should be preheated in a water bath to ensure that the temperature of the alkali solution is between 60°C and 80°C at the start of the electrolytic cell operation. After one hour of operation, the temperature of the alkali solution should stabilize at 60°C. Open the electrochemical workstation, select linear scan voltammetry, and perform a linear scan from the initial potential to the termination potential to obtain the polarization curve. In the embodiments of this invention, the ion-solvated membrane was characterized by polarization curves at 60°C and 30 wt% KOH with a commercially available non-precious catalyst.

[0062] As can be seen from the comparison of Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, Example 4 and Comparative Example 4, and Example 5 and Comparative Example 5, under the same voltage, the current density of each example is higher than that of the corresponding comparative example. This is because the molecular weight of the polymer, the content of branched monomers, and the film formation conditions will affect the mechanical strength and sheet resistance of the final ion-solventized film.

[0063] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An ion-solventized membrane, characterized in that, The compound includes at least one of branched polyarylene oxyindole and side-chain polyarylene oxyindole, wherein the branched polyarylene oxyindole includes at least one of compound A1, compound A2, and compound A3, and the structure of the side-chain polyarylene oxyindole is shown in compound B: The compound A1 comprises several first segments. and several second chain segments The compound A2 comprises several first segments. and several third chain segments The compound A3 comprises several first segments. Several second chain segments and several third chain segments Where a is the number of carbon atoms in the side chain, M is the aromatic unit; Ar1 ​​is the monomer with the first number of branching points, Ar2 is the monomer with the second number of branching points, and M is different from both Ar1 and Ar2.

2. The ion-solvated membrane according to claim 1, characterized in that, The structural formula of compound A1 is: The structural formula of compound A2 is: The structural formula of compound A3 is: 。 3. The ion-solvated membrane according to claim 1 or 2, characterized in that, M includes at least one of the following compounds: .

4. The ion-solvated membrane according to claim 1 or 2, characterized in that, The first quantity is 3, and Ar1 includes at least one of the following compounds: .

5. The ion-solventized membrane according to claim 1, characterized in that, The second quantity is 4, meaning Ar2 has 4 branching points, including at least one of the following compounds: , , .

6. The ion-solvated membrane according to claim 2, characterized in that, n is an integer between 100 and 5000, and m is an integer between 10 and 1000. l It is an integer between 10 and 1000, where 1 ≤ a ≤ 20.

7. The ion-solvated membrane according to claim 6, characterized in that, 1≤a≤10。 8. The ion-solvated membrane according to claim 1, characterized in that, The preparation method of the branched polyaryleneoxyindole includes: Indigo, compound M, and compound Ar1 are dissolved in a first organic solvent, and an acid catalyst is added at -10℃ to 0℃ to carry out the reaction, yielding compound A1; or, Indigo, compound M, and compound Ar2 are dissolved in a first organic solvent, and an acid catalyst is added at -10℃ to 0℃ to carry out the reaction, yielding compound A2; or, Indigo, compound M, compound Ar1, and compound Ar2 were dissolved in a first organic solvent, and an acid catalyst was added at -10℃ to 0℃ to carry out the reaction, yielding compound A3.

9. The ion-solvated membrane according to claim 1, characterized in that, The preparation method of the side-chain type polyaryleneoxyindole includes: Indigo and compound M were dissolved in a first organic solvent, and an acid catalyst was added at -10℃ to 0℃ to carry out the reaction, yielding polyaryleneoxyindole; The polyarylene oxyindole and bromool were dissolved in an organic solvent and reacted under alkaline conditions at 75°C to 85°C to obtain side-chain polyarylene oxyindole.

10. A method for preparing an ion-solvated film as described in any one of claims 1 to 9, characterized in that, include: The branched polyarylene oxygen indole is dissolved in a second organic solvent to obtain a first film-forming solution, and the first film-forming solution is used to form a film to obtain an ion-solventized film. or, The side-chain polyaryleneoxyindole is dissolved in a second organic solvent to obtain a second film-forming solution. The second film-forming solution is then used to form a film to obtain an ion-solventized film; or... The branched polyarylene oxyindole and the side-chain polyarylene oxyindole are dissolved in a second organic solvent to obtain a branched polyarylene oxyindole solution and a side-chain polyarylene oxyindole solution, respectively. The branched polyarylene oxyindole solution and the side-chain polyarylene oxyindole solution are mixed to obtain a third film-forming solution. The third film-forming solution is used to form a film to obtain an ion-solventized film.

11. The method for preparing an ion-solvated membrane according to claim 10, characterized in that, The film formation method is coating by scraping.

12. The method for preparing an ion-solvated film according to claim 11, characterized in that, The temperature for the coating process is 50℃~90℃.

13. The method for preparing the ion-solvated film according to claim 10, characterized in that, The second organic solvent includes at least one of N-methylpyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, and dimethyl sulfoxide.

14. The method for preparing an ion-solvated film according to claim 10, characterized in that, The solid content of the first film-forming liquid, the second film-forming liquid, and the third film-forming liquid is all 10% to 35%.

15. The use of the ion-solventizing membrane as described in claim 1 in hydrogen production by water electrolysis.

16. An alkaline electrolytic cell, characterized in that, The ion-solvated membrane includes any one of claims 1 to 9 or any one of claims 10 to 14.

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