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CN-121976246-A - Nanoparticle doped polybenzimidazole ion solvation membrane and preparation method and application thereof

CN121976246ACN 121976246 ACN121976246 ACN 121976246ACN-121976246-A

Abstract

The invention discloses a nanoparticle doped polybenzimidazole ion solvation membrane and a preparation method and application thereof, wherein the preparation method of the ion solvation membrane comprises the steps of carrying out polycondensation reaction on 3, 3-diaminobenzidine monomer and terephthalic acid monomer in polyphosphoric acid under the protection of nitrogen to obtain a viscous solution containing benzimidazole polymer; dispersing inorganic nano particles in a phosphoric acid solution, adding the inorganic nano particles into the obtained polymer solution, continuously stirring, and then carrying out vacuum degassing to obtain a casting solution, pouring the casting solution on a glass plate, carrying out blade coating by using an applicator, hydrolyzing at room temperature, taking down the film from the glass plate, soaking the film in a carbonate solution to wash out residual phosphoric acid, and soaking the film in an alkali solution for storage to obtain the doped polybenzimidazole ion solvated film. The composite membrane obtained by the invention shows more excellent ion conductivity, structural stability and electrolysis performance in alkaline electrolyzed water, and provides an ion solvation membrane material with better performance for hydrogen production by alkaline electrolyzed water.

Inventors

  • RUAN HUIMIN
  • LIN ZHIHAO
  • Shen jiangnan
  • XU ZHIPENG

Assignees

  • 浙江工业大学

Dates

Publication Date
20260505
Application Date
20260114

Claims (10)

  1. 1. The preparation method of the nanoparticle doped polybenzimidazole ion solvation membrane is characterized by comprising the following steps of: step 1, stirring 3,3 diamino benzidine monomer and terephthalic acid monomer in polyphosphoric acid under the protection of nitrogen to perform polycondensation reaction to obtain a viscous solution containing benzimidazole polymer, wherein the benzimidazole polymer has the following structural formula: ; in the structural formula, n is a positive integer greater than zero; step 2, dispersing inorganic nano particles in a phosphoric acid solution, then adding the inorganic nano particles into the polymer solution obtained in the step 1, continuously stirring for 0.5-2h, and then carrying out vacuum degassing to obtain a casting solution; And 3, pouring the casting solution obtained in the step 2 on a glass plate, carrying out knife coating by using an applicator, hydrolyzing at room temperature, taking the film off the glass plate, soaking in a carbonate solution to wash away residual phosphoric acid, soaking in an alkali solution and preserving to obtain the doped polybenzimidazole ion solvated film.
  2. 2. The method for preparing a nanoparticle-doped polybenzimidazole ion solvated membrane according to claim 1, wherein in step 1, the polyphosphoric acid is subjected to the following pretreatment step before being applied to the reaction, and is stirred for 1-2 hours at 100-160 ℃ under nitrogen atmosphere.
  3. 3. The process for preparing a nanoparticle-doped polybenzimidazole ion solvated membrane according to claim 1, wherein in step 1, the molar ratio of 3,3 diaminobenzidine to terephthalic acid is 0.8-1.2:1, preferably 1:1, and the mass ratio of 3,3 diaminobenzidine to polyphosphoric acid is 0.015-0.035:1.
  4. 4. The method of claim 1, wherein in step 1, the polycondensation is performed in stages, the two monomers are first reacted at 135-145 ℃ for 1-3 hours, the two monomers are fully dissolved and mixed and subjected to polycondensation to form an oligomer, and then the oligomer is reacted at 155-165 ℃ for 1-3 hours to remove byproduct water, and then reacted at 180-190 ℃ for 15-30 hours.
  5. 5. The method for preparing a nanoparticle-doped polybenzimidazole ion solvated membrane according to claim 1, wherein the nanoparticle is one of silicon carbide, silica, and zirconia.
  6. 6. The method for preparing the nanoparticle-doped polybenzimidazole ion solvated membrane according to claim 1, wherein the mass ratio of the nanoparticles in step 2 to 3, 3-diaminobenzidine in step 1 is 0.1-1:1, preferably 0.35-0.70:1, the concentration of the phosphoric acid solution in step 2 is 75-85%, and the dispersion concentration of the nanoparticles in the phosphoric acid solution is 0.01-0.1g/mL.
  7. 7. The method of claim 1, wherein the doctor blade thickness of the casting solution in step 3 is 200-400um.
  8. 8. The method of preparing a nanoparticle-doped polybenzimidazole ion solvated membrane according to claim 1, wherein in step 3, the membrane is hydrolyzed at a relative humidity of 30-80% and at a temperature of 20-40 ℃ for 6-12 hours; in the step 3, the carbonate solution is potassium carbonate or sodium bicarbonate water solution with the mass concentration of 5-15%, the soaking time is at least 20h, and the alkali solution used for preservation is potassium hydroxide or sodium hydroxide solution with the concentration of 0.1-1 mol/L.
  9. 9. A nanoparticle doped polybenzimidazole ion solvated membrane prepared by the process of any one of claims 1-8.
  10. 10. Use of a nanoparticle-doped polybenzimidazole ion solvation membrane according to claim 9 in alkaline electrolysis of water.

Description

Nanoparticle doped polybenzimidazole ion solvation membrane and preparation method and application thereof Technical Field The invention relates to a polybenzimidazole ion solvation membrane doped with nano particles, a preparation method thereof and application thereof in alkaline electrolyzed water. Background Hydrogen is a rich secondary energy source and has the advantages of high energy density and zero pollutant emission. Among the various hydrogen production processes, alkaline electrolyzed water is most prominent, using a porous membrane to separate the oxygen and hydrogen being formed, and the porous membrane for alkaline electrolyzed water does not have an inherent hydroxyl-conducting capacity, and relies entirely on the electrolyte to establish OH-transfer channels, which also results in its low hydrogen production efficiency. In order to increase the AWE rate, the development of ion membrane materials for alkaline cells has become a major focus. The ion solvation membrane is a functional membrane material which can regulate and control ion solvation structure and realize high-efficiency and selective transmission of ions, and combines the mechanical strength and air tightness of the polymer with the conductivity of alkali liquor. As with the porous separator, the Ion Solvating Membrane (ISMs) also does not have inherent OH-conductivity, swells in the presence of a strong alkaline electrolyte to form a polymer/water/KOH electrolyte ternary electrolyte system, and simultaneously utilizes absorption of alkaline solution to achieve OH-conductivity. The molecular structure of ISMs for alkaline electrolyzed water is mainly Polybenzimidazoles (PBI). The organic-inorganic composite strategy compensates for the short performance plate of a single organic film or inorganic film by synergistically optimizing the ion conduction, stability and interface suitability of the film, and takes the Zirfon product of Agfa as an example, the surface coating slurry contains zirconium dioxide and polymer, and inorganic matters such as zirconium dioxide and the like are aimed at inhibiting the swelling and degradation of the organic film in high-concentration KOH and providing precise aperture or ionic-philic sites, so that a continuous OH-transmission channel is constructed. Disclosure of Invention Aiming at the technical problems existing in the prior art, the invention aims to provide a polybenzimidazole ion solvation membrane doped with nano particles, and a preparation method and application thereof. In order to achieve the aim of the invention, the invention adopts the following technical scheme: in a first aspect, the invention provides a method for preparing a doped polybenzimidazole ion solvation composite membrane, which comprises the following steps: step 1, stirring 3,3 diamino benzidine and terephthalic acid in polyphosphoric acid under the protection of nitrogen to perform polycondensation reaction to obtain a viscous solution containing benzimidazole polymer, wherein the benzimidazole polymer has the following structural formula: 。 in the structural formula, n is a positive integer greater than zero; step 2, dispersing inorganic nano particles in a phosphoric acid solution, then adding the inorganic nano particles into the polymer solution obtained in the step 1, continuously stirring for 0.5-2h, and then carrying out vacuum degassing to obtain a casting solution; And 3, pouring the casting solution obtained in the step 2 on a glass plate, carrying out knife coating by using an applicator, hydrolyzing at room temperature, taking the film off the glass plate, soaking in a carbonate solution to wash away residual phosphoric acid, soaking in an alkali solution and preserving to obtain the doped polybenzimidazole ion solvated film. Further, in the step 1, the polyphosphoric acid is subjected to the following pretreatment step in advance before being applied to the reaction, and is stirred for 1-2 hours at 100-160 ℃ under nitrogen atmosphere. Further, in step 1, the molar ratio of 3,3 diaminobenzidine to terephthalic acid is 0.8-1.2:1, preferably 1:1, and the mass ratio of 3,3 diaminobenzidine to polyphosphoric acid is 0.015-0.035:1. Further, in the step 1, the polycondensation reaction is performed in stages, firstly, the two monomers are fully dissolved and mixed at 135-145 ℃ for 1-3 hours, the polycondensation reaction is performed to generate an oligomer, then, the reaction is performed at 155-165 ℃ for 1-3 hours to remove byproduct water, and then, the reaction is performed at 180-190 ℃ for 15-30 hours. In the polycondensation reaction process of the invention, the first two stages (reaction at temperatures of 135-145 ℃ and 155-165 ℃) are to slowly and uniformly raise the temperature of the polymer so as to avoid the generation of side reactions caused by local excessive temperature. Further, the mass ratio of the inorganic nano particles in the step 2 to the 3, 3-diaminobenzidine in the step 1 is 0.1-1:1