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CN-121992448-A - High-wear-resistance coating stepped alkaline electrolyzed water composite diaphragm and preparation method and application thereof

CN121992448ACN 121992448 ACN121992448 ACN 121992448ACN-121992448-A

Abstract

The invention discloses a high-wear-resistance alkaline electrolyzed water composite diaphragm with a stepped coating, and a preparation method and application thereof. The alkaline electrolyzed water composite membrane comprises a substrate supporting layer and high-hydrophilicity coatings arranged on two sides of the substrate supporting layer, and further comprises high-wear-resistance coatings arranged on the surfaces of the high-hydrophilicity coatings, wherein the substrate supporting layer is a supporting mesh, the high-hydrophilicity coatings comprise organic polymers containing active groups and first inorganic hydrophilic fillers, and the high-wear-resistance coatings comprise organic polymers with high wear resistance and second inorganic hydrophilic fillers. The invention improves the strength of the composite diaphragm coating from two aspects, firstly, the stepped design of the composite diaphragm coating structure increases the use stability of the diaphragm, ensures the comprehensive performance of the diaphragm, and secondly, a coupling agent is added into the slurry to promote the crosslinking among the organic framework, the inorganic filler and the grid cloth supporting substrate, thus forming the high-performance composite diaphragm with high bonding strength, high wear resistance and difficult falling of the coating.

Inventors

  • CHEN GUIMIN
  • CUI TONG
  • MA YIRAN

Assignees

  • 苏州希倍优氢能源科技有限公司

Dates

Publication Date
20260508
Application Date
20260120

Claims (10)

  1. 1. The preparation method of the alkaline electrolyzed water composite membrane with high wear resistance and stepped coating is characterized by comprising the following steps: providing a support screen cloth, wherein the support screen cloth is subjected to corona treatment or low-temperature plasma treatment to obtain the support screen cloth with active groups on the surface; providing an organic polymer solution containing active groups, and mixing the organic polymer solution with a first inorganic hydrophilic filler to obtain high-hydrophilic coating slurry; Mixing an organic polymer solution with stronger wear resistance with a second inorganic hydrophilic filler to obtain high wear-resistant coating slurry; And coating the high-hydrophilicity coating slurry on the two sides of the support screen cloth with active groups on the surface to obtain an inner high-hydrophilicity coating, carrying out air bath for 3-5min at 25-30 ℃, coating the high-wear-resistance coating slurry on the inner high-hydrophilicity coating to form a high-wear-resistance coating, and carrying out phase inversion to obtain the alkaline electrolyzed water composite membrane.
  2. 2. A method of making a porous membrane according to claim 1 wherein the support scrim is selected from the group consisting of fabrics, porous membranes, and felts made of polytetrafluoroethylene and/or polyphenylene sulfide; the active group comprises a hydroxyl group and/or a carboxyl group; the low temperature plasma treatment parameters are that the power is 150-300W for 30-60s; the parameters of the corona treatment are that the voltage is 12-20kV, the electrode gap is 2-5mm, the working frequency is 15-30Hz, and the treatment time is 5-30s.
  3. 3. The method of claim 1, wherein the organic polymer comprising reactive groups is selected from the group consisting of hydroxylated polysulfones and/or sulfonated polysulfones, and wherein the reactive groups comprise one or more of hydroxyl groups, sulfonic acid groups, and carboxyl groups; the mass ratio of the organic polymer containing active groups to the first inorganic hydrophilic filler is 1 (2.5-4); the content of the organic polymer in the high-hydrophilicity coating slurry is 15-18wt%; the highly hydrophilic coating slurry further includes a first silane cross-linking agent.
  4. 4. The method of preparing as claimed in claim 3, wherein the first silane crosslinking agent is selected from one or more of epoxy silane coupling agents, alkyl silane coupling agents and phenyl silane coupling agents; the content of the first silane crosslinking agent in the high-hydrophilicity coating slurry is 0.1-0.5 wt%.
  5. 5. The method according to claim 1, wherein the mass ratio of the organic polymer having a relatively high abrasion resistance to the second inorganic hydrophilic filler is 1 (1-2.5); organic polymers with relatively strong abrasion resistance include polyarylsulfones; The content of the organic polymer with stronger wear resistance in the high wear-resistant coating slurry is 18-21wt%; The high wear-resistant coating slurry also comprises a second silane cross-linking agent; The first inorganic hydrophilic filler and the second inorganic hydrophilic filler are respectively and independently selected from one or more of titanium dioxide, silicon dioxide, cerium dioxide, zirconium dioxide and hydrotalcite, and the particle size range is 20-150.
  6. 6. The method of preparing as claimed in claim 5, wherein the second silane cross-linking agent is selected from one or more of epoxy silane coupling agent, alkyl silane coupling agent and phenyl silane coupling agent; the content of the second silane cross-linking agent in the high wear-resistant coating is 0.1-0.5 wt%; the condition of phase inversion is that the composite coating is immersed in a water bath at 20-60 ℃ for 5-10min to carry out phase inversion.
  7. 7. The alkaline electrolyzed water composite membrane with high wear resistance and stepwise coating is characterized by being prepared by the preparation method of any one of claims 1-6, comprising a substrate supporting layer, high-hydrophilicity coatings arranged on two sides of the substrate supporting layer and high wear resistance coatings arranged on the surfaces of the high-hydrophilicity coatings; the substrate supporting layer is a supporting mesh; The high-hydrophilicity coating comprises an organic polymer containing active groups and a first inorganic hydrophilic filler; The high wear resistant coating comprises an organic polymer having a relatively high wear resistance and a second inorganic hydrophilic filler.
  8. 8. The alkaline electrolyzed water composition membrane according to claim 7, wherein the highly hydrophilic coating further comprises a first silane crosslinking agent, and the content of the first silane crosslinking agent in the highly hydrophilic coating slurry is 0.1wt% to 0.5wt%; the high wear-resistant coating slurry also comprises a second silane cross-linking agent, wherein the content of the second silane cross-linking agent in the high wear-resistant coating is 0.1-0.5 wt%.
  9. 9. The alkaline electrolyzed water composition membrane according to claim 7, wherein the mass ratio of the organic polymer containing active groups to the first inorganic hydrophilic filler is 1 (2.5-4); The mass ratio of the organic polymer with stronger wear resistance to the second inorganic hydrophilic filler is 1 (1-2.5); the supporting mesh is selected from fabrics, porous films or felts made of polytetrafluoroethylene and/or polyphenylene sulfide containing active groups; The organic polymer containing active groups is selected from hydroxylated polysulfone and/or sulfonated polysulfone, and the active groups comprise one or more of hydroxyl, sulfonic acid and carboxyl; The first inorganic hydrophilic filler and the second inorganic hydrophilic filler are respectively and independently selected from one or more of titanium dioxide, silicon dioxide, cerium dioxide, zirconium dioxide and hydrotalcite; organic polymers with relatively high abrasion resistance include polyarylsulfones.
  10. 10. An alkaline water electrolysis device, characterized by comprising the alkaline water electrolysis composite diaphragm with high wear resistance and stepped coating according to any one of claims 7-9.

Description

High-wear-resistance coating stepped alkaline electrolyzed water composite diaphragm and preparation method and application thereof Technical Field The invention relates to the technical field of hydrogen production by alkaline electrolyzed water, in particular to a high-wear-resistance alkaline electrolyzed water composite diaphragm with a stepped coating, and a preparation method and application thereof. Background In the global clean energy transformation climax, the alkaline water electrolysis hydrogen production technology becomes one of important means for realizing the aim of carbon neutralization due to the high-efficiency and clean characteristics. The history of the alkaline water electrolysis hydrogen production technology can be traced to the 20 th century, and the industrial application is just started. In this process, the diaphragm is a key material, and has undergone technical innovation from asbestos diaphragm to PPS diaphragm to composite diaphragm. Asbestos diaphragms are the first generation of products, being gradually eliminated due to their swelling in alkaline electrolytes and their potential harm to the human body. Subsequently, PPS separators are becoming the mainstream of the market due to their excellent heat resistance, mechanical strength, and electrical properties. However, the PPS membrane has weaker hydrophilicity, which results in larger internal resistance of the electrolytic cell and increases the unit hydrogen production cost. To overcome this disadvantage, composite membranes have been developed. By coating slurry containing hydrophilic inorganic substances, polymers and other substances on a substrate material such as PPS, the hydrophilicity of the substrate material is greatly improved, so that the internal resistance and the electricity consumption of the electrolytic cell are reduced. The composite diaphragm has remarkable electrochemical performance, but the phenomenon of inorganic powder falling off in a coating can occur through continuous high-speed flushing of electrolyte in long-term operation of an electrolytic tank, and the phenomenon can be improved by increasing the using amount of a polymer binder, but the hydrophilicity of the diaphragm is affected. Disclosure of Invention The invention provides an alkaline electrolyzed water composite membrane with high wear resistance and stepwise coating, a preparation method and application thereof, and aims to solve the technical problems of falling risk and the like of an inorganic hydrophilic coating. The invention improves the strength of the composite diaphragm coating from two aspects, namely, the coating is coated in two layers, the inner layer is a high-hydrophilicity coating, when the inner layer coating is configured, the proportion of inorganic hydrophilic powder is improved to keep the high hydrophilicity of the composite diaphragm, the outer layer strong skeleton supporting layer is coated outside on the basis of the inner high-hydrophilicity coating, the slurry of the layer is configured, the proportion of inorganic hydrophilic filler is reduced, the content of organic polymer skeleton is correspondingly increased, and meanwhile, polyarylsulfone is used for replacing common polysulfone, and the polyarylsulfone is used as a polymer skeleton, so that the composite diaphragm has stronger wear resistance, and the phenomenon of powder removal and coating removal of the surface of the composite diaphragm in the working condition of high-speed high-temperature alkali liquor scouring can be greatly reduced. The coupling agent is added into the slurry to promote the crosslinking among the organic framework, the inorganic filler and the grid cloth supporting substrate, so that the high-performance composite membrane with high bonding strength, high wear resistance and difficult falling-off of the coating is formed. The first aim of the invention is to provide a preparation method of an alkaline electrolyzed water composite membrane with high wear resistance and stepped coating, which comprises the following steps: providing a support screen cloth, wherein the support screen cloth is subjected to corona treatment or low-temperature plasma treatment to obtain the support screen cloth with active groups on the surface; providing an organic polymer solution containing active groups, and mixing the organic polymer solution with a first inorganic hydrophilic filler to obtain high-hydrophilic coating slurry; Mixing an organic polymer solution with stronger wear resistance with a second inorganic hydrophilic filler to obtain high wear-resistant coating slurry; And coating the high-hydrophilicity coating slurry on the two sides of the support screen cloth with active groups on the surface to obtain an inner high-hydrophilicity coating, carrying out air bath for 3-5min at 25-30 ℃, coating the high-wear-resistance coating slurry on the inner high-hydrophilicity coating to form a high-wear-resistance coating, and carrying ou