Anti-peeling alkaline electrolyzed water diaphragm casting liquid and diaphragm, preparation method and use

Abstract

The present invention relates to the technical field of alkaline water electrolysis hydrogen production, and specifically to an anti-stripping alkaline water electrolysis diaphragm casting liquid and a diaphragm, a preparation method and a use. The anti-stripping alkaline water electrolysis diaphragm casting liquid is made of necessary solvents, polydimethylsiloxane materials, polysulfone materials, inorganic nanoparticles, pore-forming agents, crosslinking agents, and catalysts. The polydimethylsiloxane material works together with the crosslinking agent and the catalyst to improve the envelopment of inorganic nanoparticles, improve the mechanical properties of the casting liquid on the diaphragm support layer, and exert an anti-stripping effect. The diaphragm prepared by the alkaline water electrolysis diaphragm casting liquid shows low surface resistance and anti-stripping performance, and the diaphragm has good air tightness, and is suitable for preparing the diaphragm of alkaline water electrolysis hydrogen production equipment, thereby playing the role of maintaining the free movement of ions in the electrolytic cell and blocking the mixing of hydrogen and oxygen.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production by alkaline water electrolysis, and in particular to an anti-stripping alkaline water electrolysis diaphragm casting liquid and diaphragm, a preparation method and use. Background Art

[0002] As a clean, carbon-free and storable secondary energy, hydrogen energy has the advantages of high efficiency, renewable and abundant sources. It can help large-scale consumption of renewable energy, realize large-scale peak load regulation of power grids and cross-seasonal and cross-regional energy storage, and accelerate the low-carbonization of industries, construction, transportation and other fields. In recent years, hydrogen energy has gradually become an important part of the energy strategies of various countries and is regarded as the "ultimate energy" that can solve energy and environmental problems. Compared with the high consumption and high emissions of methods such as fossil fuel hydrogen production and high-temperature decomposition hydrogen production, renewable energy water electrolysis hydrogen production technology can achieve high purity, zero emissions and sustainability of hydrogen, and will become the main trend of hydrogen production in the future.

[0003] Alkaline water electrolysis is the earliest industrialized hydrogen production technology. Alkaline water electrolysis equipment and process are relatively stable, easy to operate and control, and the positive and negative electrode plates do not require the use of precious metals. It is currently the most mature and economical water electrolysis hydrogen production technology. In the process of water electrolysis hydrogen production, the diaphragm, as a core component, plays two main functions in the electrolyzer: 1) Allowing the free movement of ions in the circuit of the electrolyzer without increasing the internal resistance. 2) Isolating the hydrogen and oxygen produced by the electrocatalytic process to achieve the separation of hydrogen and oxygen. Therefore, the air tightness of the diaphragm is crucial. The diaphragms used for alkaline water electrolysis hydrogen production include asbestos diaphragms, polyphenylene sulfide diaphragms and composite diaphragms. Asbestos diaphragms have been less used due to their shortcomings such as easy swelling, chemical instability, and the generated dust damaging the lungs. The polyphenylene sulfide diaphragm made by weaving polyphenylene sulfide fibers has poor hydrophilicity and cannot be fully wetted by the electrolyte. At the same time, its large resistance makes the electrolysis efficiency of the electrolyzer too low, which greatly wastes electricity resources. Therefore, composite diaphragms have become a hot topic in the research of hydrogen production by alkaline diaphragm water electrolysis. Composite diaphragms usually consist of three parts: polymer, inorganic nanoparticles and support network. However, existing composite diaphragms are often prone to powder loss and coating shedding during use due to the weak bonding performance between polymer, inorganic nanoparticles and support layer, which seriously affects the service life and safety of the diaphragm.

[0004] Chinese patent document CN117328102A discloses a diaphragm for producing hydrogen by electrolysis of water. The diaphragm consists of three parts: a porous support layer, a porous hydrophilic layer and a surface strengthening layer. The surface strengthening layer has a highly three-dimensional cross-linked structure, which enhances the overall strength of the diaphragm and prevents the diaphragm from cracking and falling off during use. However, the surface strengthening layer material is complex and requires 2 to 3 materials to be combined to improve the conductivity efficiency, peeling resistance and other properties. At the same time, the diaphragm preparation process is complicated and the overall effect is still not ideal.

[0005] Chinese patent document CN117305902A discloses an alkaline water electrolysis composite membrane, which also includes a porous support layer and a porous hydrophilic layer, wherein the porous hydrophilic layer includes components such as high molecular polymer, inorganic hydrophilic particles, inorganic thermal conductive particles, pore-forming agent, coupling agent, and adhesive. However, the overall effect is not ideal. For example, when the tear resistance is good, its surface resistance is high, and the overall performance of the membrane is still poor.

[0006] Therefore, the development of composite diaphragm materials with good comprehensive effects in terms of surface resistance and peeling resistance is still a problem that needs to be solved in the field of alkaline water electrolysis hydrogen production technology, and it has important industrial value. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide an anti-stripping alkaline electrolysis water diaphragm casting solution and diaphragm, a preparation method and use.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] The invention discloses an alkaline electrolytic water diaphragm casting solution for resisting peeling, wherein the casting solution is made of necessary solvent and the following materials: polydimethylsiloxane material, polysulfone material, inorganic nanoparticles, pore-forming agent, cross-linking agent and catalyst; the polydimethylsiloxane material is selected from at least one of terminal hydroxyl type polydimethylsiloxane and terminal vinyl type polydimethylsiloxane; the polysulfone material is selected from at least one of polysulfone, polyethersulfone, polyphenylsulfone, sulfonated polysulfone, sulfonated polyethersulfone and sulfonated polyphenylsulfone; the inorganic nanoparticles are selected from at least one of zirconium oxide, cerium oxide, silicon oxide, titanium oxide and barium sulfate; the pore-forming agent is selected from at least one of polyvinyl pyrrolidone, ... At least one of glycol, glycerol, and lithium chloride; the cross-linking agent is selected from at least one of methyltriacetoxysilane, di-tert-butoxydiacetoxysilane, ethyltriacetoxysilane, methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, propyltributylacetoximate silane, phenyltributylacetoximate silane, and vinyltributylacetoximate silane; the catalyst is selected from at least one of dibutyltin oxide, dibutyltin dibutyrate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and stannous octoate; the weight ratio of the polydimethylsiloxane material to the polysulfone material is (1~3):5.

[0010] Preferably, the weight ratio of the polysulfone material to the inorganic nanoparticles is 1:(2-6); the weight ratio of the polysulfone material to the pore-forming agent is 1:(0.05-0.4); the weight ratio of the polydimethylsiloxane material to the cross-linking agent is 1:(0.1-0.5); the weight ratio of the polydimethylsiloxane material to the catalyst is 1:(0.1-0.5).

[0011] Preferably, the polydimethylsiloxane material is hydroxyl-terminated polydimethylsiloxane.

[0012] A method for preparing an anti-stripping alkaline electrolyzed water diaphragm casting solution comprises the following steps:

[0013] S1: taking a polydimethylsiloxane material, and adding a diluting organic solvent to prepare a first dilution solution;

[0014] S2: Take polysulfone material, inorganic nanoparticles, pore-forming agent, add organic solvent for casting solution, add first diluent, cross-linking agent, catalyst and stir to obtain alkaline electrolyzed water diaphragm casting solution.

[0015] Preferably, the organic solvent for dilution is at least one selected from toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, n-hexane, and cyclohexane.

[0016] Preferably, the organic solvent for the casting solution is selected from at least one of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide and N,N-methylacetamide.

[0017] Preferably, in the first diluent, the weight ratio of the polydimethylsiloxane material to the dilution organic solvent is 1:1.

[0018] Preferably, in the alkaline electrolyzed water diaphragm casting solution, the weight ratio of the polysulfone material to the organic solvent for the casting solution is 1:(4-6).

[0019] An alkaline water electrolysis membrane prepared by using the aforementioned anti-peeling alkaline water electrolysis membrane casting solution, the alkaline water electrolysis membrane is made of a support layer and the alkaline water electrolysis membrane casting solution, and the preparation method of the alkaline water electrolysis membrane comprises the following steps:

[0020] M1: Take the support layer and soak it in an organic solvent for cleaning, then wash it with deionized water, and dry it to obtain a pretreated support layer;

[0021] M2: applying the alkaline electrolyzed water diaphragm casting liquid by scraping on a glass plate, then laminating the first side surface of the pre-treated support layer to the surface of the alkaline electrolyzed water diaphragm casting liquid, and then scraping the alkaline electrolyzed water diaphragm casting liquid on the second side surface of the pre-treated support layer to obtain a pre-treated liquid film;

[0022] M3: Take the pre-treated liquid membrane, dry it, and immerse it in a gel tank containing a liquid membrane treatment agent to obtain an alkaline water electrolysis membrane.

[0023] Preferably, the support layer is selected from polyphenylene sulfide fiber fabric. Further preferably, the mesh size of the polyphenylene sulfide fiber fabric is 50 mesh to 100 mesh.

[0024] Preferably, in step M1, the organic solvent for cleaning is selected from at least one of methanol, ethanol, petroleum ether, isopropanol and acetone.

[0025] Preferably, in step M1, the soaking time of the cleaning organic solvent is 1 hour to 12 hours.

[0026] Preferably, in step M1, the drying temperature is 40° C. to 100° C., and the drying time is 1 h to 8 h.

[0027] Preferably, in step M2, the coating thickness of the alkaline electrolyzed water diaphragm casting solution on the glass plate is 200 μm to 500 μm.

[0028] Preferably, in step M2, the thickness of the coating of the alkaline electrolyzed water diaphragm casting solution on the second side surface of the pretreated support layer is 200 μm to 500 μm.

[0029] Preferably, in step M3, the drying temperature is 60° C. to 100° C., and the drying time is 5 to 90 minutes.

[0030] Preferably, in step M3, the liquid membrane treatment agent is selected from at least one of water, ethanol, N,N-dimethylformamide mixed solvent containing water or ethanol, N,N-dimethylacetamide mixed solvent containing water or ethanol, N-methylpyrrolidone mixed solvent containing water or ethanol, and dimethyl sulfoxide mixed solvent containing water or ethanol, and the immersion time is 0.1h~12h.

[0031] The application of the above-mentioned alkaline water electrolysis membrane in the preparation of alkaline water electrolysis hydrogen production equipment.

[0032] The liquid membrane treating agent in the gel tank is usually used to induce gelation and film formation, and the liquid membrane treating agent is usually called a non-solvent.

[0033] The alkaline water electrolysis diaphragm is one of the core components of the electrolyzer for producing hydrogen by alkaline water electrolysis. It is used to maintain the free movement of ions in the electrolyzer and prevent the mixing of hydrogen and oxygen.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The anti-stripping alkaline water electrolysis diaphragm casting liquid of the present invention is used to prepare a diaphragm for alkaline water electrolysis hydrogen production, and has the comprehensive advantages of anti-stripping and no influence on surface resistance, which is beneficial to improving the life of the diaphragm, and does not affect the efficiency of water electrolysis hydrogen production, and the diaphragm has good air tightness.

[0036] (2) The anti-peeling alkaline electrolyzed water diaphragm casting liquid of the present invention achieves the above-mentioned comprehensive advantages without the need for additional coating steps. The casting liquid coating can achieve the comprehensive effects of anti-peeling, no effect on surface resistance, and ensuring airtightness. Therefore, the preparation method of the diaphragm is simple and conducive to promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a scanning electron microscope picture of the composite diaphragm of the present invention. DETAILED DESCRIPTION

[0038] To make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. Of course, the specific embodiments described in this section are only used to explain the present invention and are not used to limit the scope of protection of the present invention.

[0039] Unless otherwise specified, the chemical reagents and materials in the present invention can be purchased from the market or synthesized from raw materials purchased from the market; the process methods used in the embodiments, unless otherwise specified, are conventional methods in the art, for example, the coating of the casting solution can be carried out using an automatic coating machine.

[0040] The hydroxy-terminated polydimethylsiloxane used in the following examples has a molecular weight of 550 Da and a viscosity of 25 cSt;

[0041] The molecular weight of the polysulfone used in the following examples is 67000Da;

[0042] The molecular weight of the polyethersulfone used in the following examples is 42000~56000Da;

[0043] The molecular weight of polyphenylsulfone used in the following examples is 75000~81000Da;

[0044] The molecular weight of the sulfonated polysulfone used in the following examples is 60,000 to 80,000 Da;

[0045] The molecular weight of the sulfonated polyethersulfone used in the following examples is 76000Da;

[0046] The molecular weight of the sulfonated polyphenylene sulfone used in the following examples is 62000 Da.

[0047] This section discloses a method for preparing an anti-peeling alkaline electrolyzed water diaphragm casting solution and a diaphragm, comprising the following steps (the serial number is not considered as a limitation on the order of the steps, for example, the pretreatment of the support layer can be completed before the scraping):

[0048] (1) The support layer is immersed in a cleaning organic solvent for cleaning, then rinsed with deionized water and dried in an oven to obtain a pretreated support layer;

[0049] (2) adding the polydimethylsiloxane material to the dilution organic solvent and mixing them evenly to obtain a first dilution solution;

[0050] (3) adding polysulfone material, inorganic nanoparticles, and pore-forming agent to an organic solvent for a casting solution and mixing, then adding a first diluent, a cross-linking agent, and a catalyst and continuing to stir to obtain an alkaline electrolyzed water diaphragm casting solution;

[0051] (4) applying an alkaline electrolyzed water membrane casting liquid to a glass plate, then laminating the first side surface of the pretreated support layer to the surface of the alkaline electrolyzed water membrane casting liquid, and then applying the alkaline electrolyzed water membrane casting liquid to a second side surface of the pretreated support layer to obtain a pretreated liquid membrane;

[0052] (5) The pretreated liquid membrane is dried and immersed in a gel tank containing a liquid membrane treatment agent to obtain an alkaline water electrolysis membrane.

[0053] The first side surface and the second side surface refer to the two side surfaces of the support layer used for coating the casting liquid, and are not regarded as limiting the scope of protection.

[0054] The present invention is further described below through specific examples. Unless otherwise specified, the following examples have the same support layer thickness (200 μm), the same scraping thickness of the alkaline electrolyzed water diaphragm casting solution (200 μm), and the same average particle size of the inorganic nanoparticles (50 nm). The support layer thickness, scraping thickness, and average particle size of the inorganic nanoparticles are only used for product performance comparison and are not considered to limit the scope of protection.

[0055] Example 1 A diaphragm for producing hydrogen by alkaline water electrolysis

[0056] The preparation method comprises the following steps:

[0057] (1) A polyphenylene sulfide fiber fabric (mesh aperture 50 mesh) with a size of 20 cm × 20 cm was soaked in petroleum ether solvent for 1 hour to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 40°C and dried for 8 hours to obtain a pretreated support layer;

[0058] (2) Add 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of dichloromethane and mix well to obtain a first dilution solution;

[0059] (3) Add 10 g of polysulfone particles, 20 g of zirconium oxide, and 0.5 g of polyvinyl pyrrolidone to 40 g of N-methylpyrrolidone solvent and stir evenly, then add 4 g of the first dilution solution, 0.2 g of methyltriacetoxysilane and 0.2 g of dibutyltin oxide and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0060] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0061] (5) The pretreated liquid membrane was placed in a 60°C oven to dry for 90 min, and then immersed in a gel tank containing deionized water and allowed to stand for 12 h to obtain a diaphragm for hydrogen production by alkaline water electrolysis.

[0062] Example 2 A diaphragm for producing hydrogen by alkaline water electrolysis

[0063] The preparation method comprises the following steps:

[0064] (1) A polyphenylene sulfide fiber fabric (mesh aperture 50 mesh) with a size of 20 cm × 20 cm was soaked in an isopropanol solvent for 2 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 50 ° C and dried for 6 h to obtain a pretreated support layer;

[0065] (2) Add 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of n-hexane and mix well to obtain a first dilution solution;

[0066] (3) Add 10 g of polyethersulfone particles, 30 g of zirconium oxide, and 0.8 g of polyethylene glycol to 45 g of dimethyl sulfoxide solvent and stir evenly, then add 5 g of the first dilution solution, 0.5 g of di-tert-butoxydiacetoxysilane, and 0.5 g of dibutyltin dibutyrate and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0067] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0068] (5) The pretreated liquid membrane was placed in a 70°C oven to dry for 60 min, and then immersed in a gel tank containing ethanol and allowed to stand for 10 h to obtain a diaphragm for alkaline water electrolysis to produce hydrogen.

[0069] Example 3 A diaphragm for producing hydrogen by alkaline water electrolysis

[0070] The preparation method comprises the following steps:

[0071] (1) A polyphenylene sulfide fiber fabric (mesh aperture 75 mesh) with a size of 20 cm × 20 cm was immersed in a mixed solvent of petroleum ether and isopropanol (the mass ratio of petroleum ether to isopropanol was 1:1) for 4 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 60 ° C and dried for 4 h to obtain a pretreated support layer;

[0072] (2) adding 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of toluene and mixing them evenly to obtain a first dilution solution;

[0073] (3) Add 10 g of polyphenylsulfone particles, 40 g of zirconium oxide, and 1 g of lithium chloride to 50 g of N,N-dimethylformamide solvent and stir evenly, then add 6 g of the first dilution solution, 0.9 g of ethyltriacetoxysilane and 0.9 g of dibutyltin diacetate and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0074] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0075] (5) The pretreated liquid membrane was placed in an oven at 80°C for drying for 45 min, and then immersed in a gel tank containing a mixed solvent of deionized water and N,N-dimethylformamide (the mass ratio of deionized water to N,N-dimethylformamide was 7:3) and allowed to stand for 8 h to obtain a diaphragm for alkaline water electrolysis to produce hydrogen.

[0076] Example 4 A diaphragm for producing hydrogen by alkaline water electrolysis

[0077] The preparation method comprises the following steps:

[0078] (1) A polyphenylene sulfide fiber fabric (mesh aperture 75 mesh) with a size of 20 cm × 20 cm was soaked in an ethanol solvent for 6 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 70 ° C and dried for 3 h to obtain a pretreated support layer;

[0079] (2) Add 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of chloroform and mix well to obtain a first dilution solution;

[0080] (3) Add 10 g of sulfonated polysulfone particles, 50 g of zirconium oxide, and 1.2 g of polyvinyl pyrrolidone to 60 g of N,N-dimethylacetamide solvent and stir evenly, then add 8 g of the first dilution solution, 1.6 g of methyl orthosilicate, and 1.6 g of dibutyltin dilaurate and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0081] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0082] (5) The pretreated liquid membrane was placed in a 90°C oven to dry for 30 min, and then immersed in a gel tank with a mixed solvent of ethanol and N,N-dimethylacetamide (the mass ratio of ethanol to N,N-dimethylacetamide was 8:2) and allowed to stand for 6 h to obtain a diaphragm for alkaline water electrolysis to produce hydrogen.

[0083] Example 5 A diaphragm for producing hydrogen by alkaline water electrolysis

[0084] The preparation method comprises the following steps:

[0085] (1) A polyphenylene sulfide fiber fabric (mesh aperture 100 mesh) with a size of 20 cm × 20 cm was soaked in acetone solvent for 8 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 80 ° C and dried for 2 h to obtain a pretreated support layer;

[0086] (2) Add 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of 1,2-dichloroethane and mix well to obtain a first dilution solution;

[0087] (3) Add 10 g of sulfonated polyphenylsulfone particles, 60 g of titanium oxide, and 1.5 g of polyethylene glycol to 60 g of a mixed solvent of N-methylpyrrolidone and N,N-dimethylformamide (the mass ratio of N-methylpyrrolidone to N,N-dimethylformamide is 1:1), stir evenly, then add 10 g of the first dilution solution, 2.5 g of tetraethyl orthosilicate, and 2.5 g of dioctyltin dilaurate, and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0088] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0089] (5) The pretreated liquid membrane was placed in an oven at 100°C to dry for 20 min, and then immersed in a gel tank containing a mixed solvent of deionized water and ethanol (the mass ratio of deionized water to ethanol was 5:5) and allowed to stand for 4 h to obtain a diaphragm for hydrogen production by alkaline water electrolysis.

[0090] Example 6 A diaphragm for producing hydrogen by alkaline water electrolysis

[0091] The preparation method comprises the following steps:

[0092] (1) A polyphenylene sulfide fiber fabric (mesh aperture 100 mesh) with a size of 20 cm × 20 cm was immersed in a mixed solvent of ethanol and acetone (the mass ratio of ethanol to acetone was 1:1) for 10 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 90 ° C and dried for 1 h to obtain a pretreated support layer;

[0093] (2) adding 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of xylene and mixing them evenly to obtain a first dilution solution;

[0094] (3) Add 10 g of sulfonated polyethersulfone particles, 50 g of silicon oxide, and 2 g of lithium chloride to 50 g of dimethyl sulfoxide solvent and stir evenly, then add 12 g of the first dilution solution, 3 g of methyltrimethoxysilane and 3 g of stannous octoate and continue stirring for 1 hour to obtain an alkaline electrolytic water diaphragm casting solution;

[0095] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0096] (5) The pretreated liquid membrane was placed in an oven at 100°C for drying for 10 min, and then immersed in a gel tank containing a mixed solvent of deionized water and dimethyl sulfoxide (the mass ratio of deionized water to dimethyl sulfoxide was 6:4) and allowed to stand for 0.1 h to obtain a diaphragm for hydrogen production by alkaline water electrolysis.

[0097] Example 7 A diaphragm for producing hydrogen by alkaline water electrolysis

[0098] The preparation method comprises the following steps:

[0099] (1) A polyphenylene sulfide fiber fabric (mesh pore size 100 mesh) with a size of 20 cm × 20 cm was soaked in a mixed solvent of methanol and petroleum ether (the mass ratio of methanol to petroleum ether was 1:1) for 12 h to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 100 ° C and dried for 1 h to obtain a pretreated support layer;

[0100] (2) adding 10 g of terminal hydroxyl polydimethylsiloxane to 10 g of cyclohexane and mixing them evenly to obtain a first dilution solution;

[0101] (3) 10 g of sulfonated polyethersulfone particles, 50 g of silicon oxide, and 4 g of polyvinyl pyrrolidone were added to 60 g of N-methylpyrrolidone solvent and stirred evenly, and then 12 g of the first dilution solution, 0.6 g of vinyl trisbutyl ketone oxime silane, and 0.6 g of dibutyltin dibutyrate were added and stirred for 1 h to obtain an alkaline electrolytic water diaphragm casting solution;

[0102] (4) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0103] (5) The pretreated liquid membrane was placed in an oven at 100°C to dry for 5 min, and then immersed in a gel tank containing a mixed solvent of deionized water and N-methylpyrrolidone (the mass ratio of deionized water to N-methylpyrrolidone was 1:1) and allowed to stand for 0.1 h to obtain a diaphragm for hydrogen production by alkaline water electrolysis.

[0104] Comparative Example 1: A diaphragm for producing hydrogen by alkaline water electrolysis

[0105] This comparative example is an existing commercial ZIRFON PERL UTP500 composite diaphragm for producing hydrogen by alkaline water electrolysis.

[0106] Comparative Example 2: A diaphragm for producing hydrogen by alkaline water electrolysis

[0107] The diaphragm for hydrogen production by alkaline water electrolysis of this comparative example does not contain polydimethylsiloxane material, crosslinking agent and catalyst, and the preparation method comprises the following steps:

[0108] (1) A polyphenylene sulfide fiber fabric (mesh aperture 50 mesh) with a size of 20 cm × 20 cm was soaked in petroleum ether solvent for 4 hours to wash away the oil and impurities on the surface of the fabric, and then the fabric was rinsed with deionized water, and then the fabric was placed in an oven at 60 ° C and dried for 4 hours to obtain a pretreated support layer;

[0109] (2) adding 10 g of polysulfone particles, 50 g of zirconium oxide, and 2 g of polyvinyl pyrrolidone into 50 g of N-methylpyrrolidone solvent and stirring the mixture to obtain an alkaline water electrolysis diaphragm casting solution;

[0110] (3) using an automatic coating machine to uniformly scrape the alkaline electrolyzed water diaphragm casting liquid onto a glass plate, then laminating one side of the cleaned pre-treated support layer on the scraped alkaline electrolyzed water diaphragm casting liquid, and then taking the alkaline electrolyzed water diaphragm casting liquid and scraping it onto the other side of the pre-treated support layer using an automatic coating machine to obtain a pre-treated liquid film;

[0111] (4) The pretreated liquid membrane was placed in a 60°C oven to dry for 90 min, and then immersed in a deionized water gel tank and allowed to stand for 12 h to obtain a diaphragm for alkaline water electrolysis to produce hydrogen.

[0112] Comparative Example 3: A diaphragm for producing hydrogen by alkaline water electrolysis

[0113] Compared with Example 4, the present diaphragm for producing hydrogen by alkaline water electrolysis does not contain dibutyltin oxide in step (3).

[0114] Performance test of diaphragm for hydrogen production by alkaline water electrolysis:

[0115] The diaphragms for producing hydrogen by alkaline water electrolysis prepared in Examples 1-7 and Comparative Examples 1-3 were tested according to the following method.

[0116] 1. Surface resistance test: According to the standard SJ / T-10171-2016 "General test method for basic properties of alkaline battery separators", the surface resistance of the embodiment and comparative example separators was tested by an electrochemical workstation;

[0117] 2. Water contact angle test: According to the provisions of standard GB / T-30693-2014 "Measurement of contact angle between plastic film and water", the test is carried out by contact angle meter;

[0118] 3. Bubble point pressure test: According to the provisions of GB / T-32361-2015 "Separation membrane pore size test method bubble point and average flow method", the test is carried out by a membrane pore size analyzer;

[0119] 4. Test of hydrogen content in oxygen: First, soak the diaphragm sample in 30% potassium hydroxide lye overnight. Install the cleaned Pt sheet and diaphragm sample in the electrolytic cell, and then connect the peristaltic pump, 30% potassium hydroxide solution lye tank and temperature control equipment to the electrolytic cell. Set the electrolysis temperature to 80℃, the electrolyte flow rate to 200 ml / min, and the current density to 300mA / cm 2 The oxygen produced by the anode is collected and passed into Shimadzu's GCMS QP2010 Plus to test the hydrogen content in the oxygen. According to the provisions of the standard GB / T-8981-2008 "Gas Chromatography for the Determination of Trace Hydrogen in Gases", the hydrogen content in the collected oxygen gas is tested by gas chromatograph;

[0120] 5. Peel strength test: According to the provisions of standard GB / T-9286-2021 "Scratch test for paints and varnishes", the peel strength of the embodiment and comparative example diaphragms was tested by the 100-grid test standard.

[0121] The average pore size of the samples was observed by scanning electron microscopy. Figure 1 As shown (the figure is a scanning electron microscope image of the composite diaphragm of embodiment 7).

[0122] The test results of the composite diaphragms prepared in Examples 1-7 and Comparative Examples 1-3 are shown in Table 1.

[0123]

[0124] According to the test data in Table 1, the surface resistance of the diaphragm of comparative example 1 is greater than the surface resistance of the diaphragm of the embodiment, which shows that the ion conductivity of the diaphragm in the prior art is lower than that of the diaphragm of the present invention; the water contact angle of the diaphragm of comparative example 1 is greater than the water contact angle of the diaphragm of the embodiment, which shows that the wettability / hydrophilicity of the diaphragm in the prior art is lower than the wettability / hydrophilicity of the diaphragm of the present invention; the bubble point pressures of the diaphragms of the embodiment are greater than the bubble point pressures of the diaphragms of comparative example 1, which shows that the air tightness of the diaphragm of the present invention is better than that of the diaphragm of comparative example 1; the hydrogen content in oxygen of the diaphragm of the embodiment is lower than the hydrogen content in oxygen of the diaphragm of comparative example 1, which shows that the ability of the diaphragm of the present invention to isolate gas is better than that of the diaphragm in the prior art; the hundred grid test grade 5B of the diaphragm of the present invention is better than the hundred grid test grade 3B of the diaphragm of comparative example 1, which shows that the peel strength of the diaphragm of the present invention is higher than the peel strength of the diaphragm in the prior art.

[0125] The surface resistance and water contact angle of the membranes of Example 2, Example 3, Example 4 and Example 5 are lower than those of the membrane of Example 1, indicating that increasing the amount of inorganic nanoparticles can improve the ion conductivity of the membrane and enhance the hydrophilicity of the membrane.

[0126] There is no significant difference in the surface resistance and water contact angle of the membrane of Example 3 and the membrane of Comparative Example 2. However, the hundred-grid test grade 5B of the membrane of Example 3 is better than the hundred-grid test grade 2B of the membrane of Comparative Example 2, and the peel strength of the membrane of Example 3 is much higher than the peel strength of the membrane of Comparative Example 2. Compared with Comparative Example 2, polydimethylsiloxane material, cross-linking agent and catalyst are added during the preparation of the membrane of Example 3, and the peel strength of the membrane of Example 3 is greatly improved. Under the action of diethyl dibutyl tin catalyst, the cross-linking condensation chemical reaction between the terminal hydroxyl polydimethylsiloxane and the ethyl triacetoxy silane cross-linking agent is beneficial to encapsulate inorganic nanoparticles to prevent them from falling off and improve the tear resistance. The hydroxyl groups of the hydroxyl-terminated polydimethylsiloxane and the hydroxyl groups on the surface of the inorganic nanoparticle zirconium oxide form hydrogen bonds, which can fix the zirconium oxide and prevent it from falling off during the process of hydrogen production by electrolysis of water; the hydroxyl groups of the polydimethylsiloxane and the siloxane groups of ethyltriacetoxysilane undergo a dealcoholization condensation reaction, and the cross-linked structure formed enhances the mechanical properties and anti-peeling properties of the diaphragm. The hydroxyl groups of the polydimethylsiloxane and the siloxane groups of ethyltriacetoxysilane in the two-scrape coating slurry react, causing them to be tightly bonded with the polyphenylene sulfide porous fabric to form a cross-linked structure, which enhances the mechanical strength of the diaphragm and improves the anti-peeling strength of the diaphragm.

[0127] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention. For example, when cleaning polyphenylene sulfide fiber fabric, the soaking time of the organic solvent used for cleaning; the drying conditions of polyphenylene sulfide fiber fabric; the coating thickness of the alkaline electrolyzed water diaphragm casting liquid; the drying conditions of the pre-treated liquid film, the immersion time in the gel tank, etc. are all conditions that can be changed by technicians in the technical field according to the specific operation.

Claims

1. An anti-stripping alkaline electrolyzed water diaphragm casting solution, characterized in that: The casting solution is made of necessary solvents and the following materials: polydimethylsiloxane material, polysulfone material, inorganic nanoparticles, pore-forming agent, cross-linking agent, and catalyst; the polydimethylsiloxane material is hydroxyl-terminated polydimethylsiloxane; the polysulfone material is selected from at least one of polysulfone, polyethersulfone, polyphenylsulfone, sulfonated polysulfone, sulfonated polyethersulfone, and sulfonated polyphenylsulfone; the inorganic nanoparticles are selected from at least one of zirconium oxide, cerium oxide, silicon oxide, titanium oxide, and barium sulfate; the pore-forming agent is selected from at least one of polyvinyl pyrrolidone, polyethylene glycol, glycerol, and lithium chloride; The crosslinking agent is selected from at least one of methyltriacetoxysilane, di-tert-butoxydiacetoxysilane, ethyltriacetoxysilane, methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, propyltributylacetoximate silane, phenyltributylacetoximate silane, and vinyltributylacetoximate silane; the catalyst is selected from at least one of dibutyltin oxide, dibutyltin dibutyrate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and stannous octoate; the weight ratio of the polydimethylsiloxane material to the polysulfone material is (1-3):5; The weight ratio of the polysulfone material to the inorganic nanoparticles is 1:(2-6); the weight ratio of the polysulfone material to the pore-forming agent is 1:(0.05-0.4); The weight ratio of the polydimethylsiloxane material to the cross-linking agent is 1:(0.1-0.5); The weight ratio of the polydimethylsiloxane material to the catalyst is 1:(0.1-0.5).

2. The method for preparing a peeling-resistant alkaline electrolyzed water diaphragm casting solution according to claim 1, characterized in that: The steps include: S1: taking a polydimethylsiloxane material, and adding a diluting organic solvent to prepare a first dilution solution; S2: Take polysulfone material, inorganic nanoparticles, pore-forming agent, add organic solvent for casting solution, add first diluent, cross-linking agent, catalyst and stir to obtain alkaline electrolyzed water diaphragm casting solution.

3. The method for preparing a peeling-resistant alkaline electrolyzed water diaphragm casting solution according to claim 2, characterized in that: The dilution organic solvent is selected from at least one of toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, n-hexane, and cyclohexane.

4. The method for preparing a peeling-resistant alkaline electrolyzed water diaphragm casting solution according to claim 2, characterized in that: The organic solvent for the casting solution is selected from at least one of N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylformamide and N,N-methylacetamide.

5. The method for preparing a peeling-resistant alkaline electrolyzed water diaphragm casting solution according to claim 2, characterized in that: In the first diluent, the weight ratio of the polydimethylsiloxane material to the dilution organic solvent is 1:

1.

6. The method for preparing a peeling-resistant alkaline electrolyzed water diaphragm casting solution according to claim 2, characterized in that: In the alkaline electrolyzed water diaphragm casting solution, the weight ratio of the polysulfone material to the organic solvent for the casting solution is 1:(4-6).

7. An alkaline water electrolysis membrane prepared by using the alkaline water electrolysis membrane casting solution according to claim 1 or the alkaline water electrolysis membrane casting solution prepared by the preparation method according to any one of claims 2 to 6, characterized in that: The alkaline water electrolysis membrane is made of a support layer and the alkaline water electrolysis membrane casting solution. The preparation method of the alkaline water electrolysis membrane comprises the following steps: M1: Take the support layer and soak it in an organic solvent for cleaning, then wash it with deionized water, and dry it to obtain a pretreated support layer; M2: applying the alkaline electrolyzed water diaphragm casting liquid by scraping on a glass plate, then laminating the first side surface of the pre-treated support layer to the surface of the alkaline electrolyzed water diaphragm casting liquid, and then scraping the alkaline electrolyzed water diaphragm casting liquid on the second side surface of the pre-treated support layer to obtain a pre-treated liquid film; M3: Take the pre-treated liquid membrane, dry it, and immerse it in a gel tank with liquid membrane treatment agent added to obtain an alkaline water electrolysis membrane.

8. The alkaline water electrolysis membrane according to claim 7, characterized in that: The supporting layer is selected from polyphenylene sulfide fiber fabric.

9. The alkaline water electrolysis membrane according to claim 8, characterized in that: The mesh pore size of the polyphenylene sulfide fiber fabric is 50 meshes to 100 meshes.

10. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M1, the organic solvent for cleaning is selected from at least one of methanol, ethanol, petroleum ether, isopropanol, and acetone.

11. The alkaline water electrolysis membrane according to claim 10, characterized in that: In step M1, the soaking time of the organic solvent for cleaning is 1 hour to 12 hours.

12. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M1, the drying temperature is 40° C. to 100° C., and the drying time is 1 h to 8 h.

13. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M2, the coating thickness of the alkaline electrolyzed water diaphragm casting solution on the glass plate is 200 μm to 500 μm.

14. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M2, the thickness of the coating of the alkaline electrolyzed water diaphragm casting solution on the second side surface of the pretreated support layer is 200 μm to 500 μm.

15. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M3, the drying temperature is 60° C. to 100° C., and the drying time is 5 min to 90 min.

16. The alkaline water electrolysis membrane according to claim 7, characterized in that: In step M3, the liquid membrane treatment agent is selected from at least one of water, ethanol, N,N-dimethylformamide mixed solvent containing water or ethanol, N,N-dimethylacetamide mixed solvent containing water or ethanol, N-methylpyrrolidone mixed solvent containing water or ethanol, and dimethyl sulfoxide mixed solvent containing water or ethanol, and the immersion time is 0.1h~12h.

17. Use of the alkaline water electrolysis membrane according to claim 7 in preparing alkaline water electrolysis hydrogen production equipment.

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