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CN-122000396-A - Cross-linked polymer-molecular cluster non-fluorine proton exchange membrane, and preparation method and application thereof

CN122000396ACN 122000396 ACN122000396 ACN 122000396ACN-122000396-A

Abstract

The invention discloses a crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane, a preparation method and application thereof, which are mainly prepared from branched Polyethylenimine (PEI), polyvinyl chloride (PVC) and phosphotungstic acid (PW 12 ), and the membrane is prepared by performing a crosslinking reaction on quaternized PEI and PVC, and then immersing the prepared membrane into PW 12 solution. The mass ratio of PEI to PVC can be adjusted according to the requirement, the mass fraction of PW 12 solution is preferably 5-20%, the proton exchange membrane has good mechanical property, thermal stability and excellent proton conductivity, and the preparation method is simple, low in cost and environment-friendly.

Inventors

  • LIU XIE
  • LIU LU
  • LIN XIAOYU

Assignees

  • 广州梵特晞生物科技有限公司

Dates

Publication Date
20260508
Application Date
20251208

Claims (9)

  1. 1. A preparation method of a cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane is characterized in that the cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane is prepared from branched polyethylenimine, polyvinyl chloride and phosphotungstic acid, and is prepared by performing cross-linking reaction on quaternized branched polyethylenimine and polyvinyl chloride, and immersing the prepared membrane into phosphotungstic acid solution, wherein the cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane structure The formula is shown in the specification.
  2. 2. The method for preparing the cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane according to claim 1, comprising the following steps: (1) The branched polyethylenimine is quaternized, namely the branched polyethylenimine is firstly dissolved in dimethylformamide solution to obtain dilute solution with the mass fraction of 4-6 percent, bromopropane is added, the molar ratio of amine groups in the bromopropane and the branched polyethylenimine is controlled, and bright yellow transparent QPEI solution is obtained after reflux reaction; (2) Adding QPEI solutions with different mass ratios prepared in the step (1) and polyvinyl chloride into an organic solvent dimethylformamide solution, heating and stirring until the polyvinyl chloride is completely dissolved, continuing stirring and reacting to obtain a pale yellow PEI-PVC mixed solution, and removing the organic solvent from the QPEI-PVC mixed solution to obtain a uniform amber transparent crosslinked polymer film; (3) Finally, soaking the prepared QPEI-PVC composite film in a phosphotungstic acid aqueous solution, taking out water on the surface, filling the water into a sealing bag, and preserving at room temperature to obtain the QPEI-PVC-PW 12 composite film.
  3. 3. The method for preparing a crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane according to claim 2, wherein in the step (1), the molar ratio of the bromopropane to the amine groups in the branched polyethylenimine is 1:1-3, and the bright yellow transparent QPEI solution is obtained after reflux reaction for 24 hours at 75-85 ℃.
  4. 4. The method for rapidly detecting outer membrane permeability of gram-negative bacteria according to claim 2, wherein in the step (2), polyvinyl chloride is added into QPEI solution to make the mass ratio of QPEI to polyvinyl chloride be 1:1-3, and the PVC is K-value 72-71.
  5. 5. The method for preparing a cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane according to claim 2, wherein QPEI and polyvinyl chloride are added into an organic solvent dimethylformamide solution in the step (2), the polymer mass fraction of the solution is controlled below 10%, and the solution is heated to 75-85 ℃ and stirred until the PVC is completely dissolved, and then the stirring reaction is continued for 6 hours at the temperature of 75-85 ℃.
  6. 6. The method for preparing a crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane according to claim 2, wherein in the step (2), QPEI-PVC mixed solution is poured into a clean glass dish, and dried under vacuum at 75 ℃ to 85 ℃ for 24 hours to completely remove the organic solvent, thereby obtaining a uniform amber transparent crosslinked polymer membrane.
  7. 7. The method for preparing a crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane according to claim 2, wherein in the step (3), the prepared QPEI-PVC composite membrane is soaked in an aqueous solution of PW 12 with a mass fraction of 5-wt-20 wt% for 10-14 hours.
  8. 8. A crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane prepared by the preparation method of any one of claims 1-7.
  9. 9. A crosslinked polymer-molecular cluster non-fluorine composite proton exchange membrane prepared by the preparation method according to any one of claims 1 to 7 for the preparation of hydrogen fuel cells.

Description

Cross-linked polymer-molecular cluster non-fluorine proton exchange membrane, and preparation method and application thereof Technical Field The invention relates to the technical field of hydrogen fuel cells, in particular to a cross-linked polymer-molecular cluster non-fluorine proton exchange membrane, a preparation method and application thereof. Background At present, under the background of global advocating energy conservation and emission reduction and domestic implementation of a 'two-carbon' policy, the development and utilization of hydrogen energy meet the stage of rapid development. Hydrogen fuel cells are receiving extensive attention by virtue of the characteristics of clean and pollution-free properties, high energy conversion efficiency, flexible application scenarios and the like, and Proton Exchange Membrane (PEM) materials are one of the core components. Perfluorosulfonic acid (PFSA) membrane materials, typified by Nafion, are currently the dominant commercial PEM, the chemical structure of which includes a hydrophobic polytetrafluoroethylene polymer backbone and a hydrophilic-SO 3 H group side chain. The special hydrophilic-hydrophobic structure endows PFSA microphase separation characteristics, hydrophilic-SO 3 H groups can form continuous nano transmission channels in a hydration state, and protons can be rapidly conducted in the continuous nano transmission channels. However, the synthesis of the perfluoropolymer and the subsequent sulfonation step must be performed through complicated synthesis process flows, so that the manufacturing cost of the PFSA is always high, and the problem of environmental and ecological pollution caused by fluorine-containing substances is also possible. Based on the above factors, the large-scale application of perfluorosulfonic acid proton exchange membranes in China is also challenged. Therefore, on the premise of ensuring the performance of high conductivity, the development of the novel non-fluorine proton conductor material with simple and green preparation process has very important significance and application value. The non-fluorine proton exchange membrane has wide and cheap material sources, and the preparation and processing cost can be well controlled. Meanwhile, the segment structure design and modification difficulty of the non-fluorine polymer are small, and proton conduction in an anhydrous environment can be realized by carrying out hybridization modification on the non-fluorine polymer, so that the proton exchange membrane can stably operate under extreme conditions such as high temperature, low humidity and the like. However, the research investment on the non-fluorine proton exchange membrane material is less, and the common products at present are sulfonated aromatic polymer proton exchange membrane materials such as sulfonated polyether ether ketone (SPEEK), sulfonated Polysulfone (SPSF), sulfonated polyether sulfone (SPES) and the like, which are difficult to consider in service stability and proton conductivity, and the overall performance is to be improved. The preparation of the non-fluorine proton exchange membrane material still has certain difficulty, and the structure-activity relationship between the service microcosmic mechanism and the processing and forming is required to be known. The organic-inorganic composite material has the special functions of a fluorine-free polymer substrate and an inorganic material filling, and can be used for preparing novel non-fluorine proton exchange membrane materials. Wherein Keggin Polyoxometallate (POMs) represented by phosphotungstic acid (PW 12) is an excellent inorganic proton conductor material, can effectively improve proton conductivity of a polymer matrix, and has good thermal stability and redox activity as a nano metal cluster with a definite structure. Thus, specific fluorine-free polymer matrixes and POMs can be compounded by a simple non-covalent physical blending mode to prepare novel nanocomposite proton conductor materials. The invention patent with the application number 202210657846.7 discloses a preparation method of a proton exchange membrane of a fuel cell, which comprises the steps of crosslinking a polyvinyl alcohol aqueous solution and polyethylene imine aqueous solutions with different mass fractions to form a membrane, soaking the membrane in heteropolyacid aqueous solutions with different concentrations, drying the membrane, quaternizing the crosslinked membrane, and finally soaking the quaternized crosslinked membrane in heteropolyacid aqueous solutions with different concentrations, and drying the membrane to prepare the proton exchange membrane. Disclosure of Invention The invention aims to provide a cross-linked polymer-molecular cluster non-fluorine composite proton exchange membrane, a preparation method and application thereof, wherein the proton exchange membrane has good mechanical property, thermal stability and excellent proton conductivity, and the