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CN-122006523-A - Polyamide composite membrane for salt difference power generation and having multi-scale heterostructure and preparation method thereof

CN122006523ACN 122006523 ACN122006523 ACN 122006523ACN-122006523-A

Abstract

The application discloses a polyamide composite membrane for salt difference power generation and having a multi-scale heterostructure and a preparation method thereof, and belongs to the technical field of membranes, wherein the polyamide composite membrane comprises a polyacrylonitrile substrate, an intermediate polyamide membrane and a surface polyamide membrane which are sequentially arranged, wherein the intermediate polyamide membrane is obtained by polycondensation reaction of m-phenylenediamine and trimesoyl chloride, the surface polyamide membrane is obtained by polycondensation reaction of 5,10,15, 20-tetra (4-aminophenyl) -21H, 23H-porphyrin and trimesoyl chloride, and the intermediate polyamide membrane and the surface polyamide membrane are mutually penetrated at an interface. The polyamide composite membrane provided by the application effectively solves the trade-off problem between the traditional permeability and the selectivity, realizes the balance between ion concentration polarization inhibition and ion selectivity, and realizes high-efficiency osmotic energy conversion.

Inventors

  • WU HUIQING
  • CAO ZIFENG
  • SUN HAOYUAN
  • WU PEIYI

Assignees

  • 东华大学

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The polyamide composite membrane for salt-tolerant power generation is characterized by comprising a polyacrylonitrile substrate, an intermediate polyamide membrane and a surface polyamide membrane which are sequentially arranged, wherein the intermediate polyamide membrane is obtained by polycondensation reaction of m-phenylenediamine and trimesoyl chloride, the surface polyamide membrane is obtained by polycondensation reaction of 5,10,15, 20-tetra (4-aminophenyl) -21H, 23H-porphyrin and trimesoyl chloride, and the intermediate polyamide membrane and the surface polyamide membrane are mutually penetrated at an interface.
  2. 2. The polyamide composite membrane for salt-tolerant power generation having a multi-scale heterostructure according to claim 1, wherein the thickness of the middle layer polyamide membrane is 70 to 90 nm, and the thickness of the surface layer polyamide membrane is 30 to 40 nm.
  3. 3. The method for producing a polyamide composite membrane for salt-differential power generation and having a multi-scale heterostructure according to claim 1, comprising the steps of: (1) Preparing a polyacrylonitrile substrate; (2) Sequentially immersing a polyacrylonitrile substrate into a first solution and a second solution, wherein the first solution is obtained by mixing m-phenylenediamine, sodium hydroxide, a surfactant and water; The second solution is obtained by mixing trimesic acid chloride and cyclohexane; (3) Immersing the product of the step (2) into a third solution and a second solution in sequence; the third solution is obtained by mixing 5,10,15, 20-tetra (4-aminophenyl) -21H, 23H-porphyrin and hydrochloric acid aqueous solution; (4) And (3) heating and crosslinking the product of the step (3) to obtain the polyamide composite membrane.
  4. 4. The method for producing a polyamide composite membrane for salt-differential power generation having a multi-scale hetero structure according to claim 3, wherein in the first solution, the surfactant is sodium dodecylbenzenesulfonate.
  5. 5. The method for preparing a polyamide composite membrane for salt-tolerant power generation and having a multi-scale heterostructure according to claim 3, wherein the mass fraction of the surfactant in the first solution is 0.02 to 0.6 wt%.
  6. 6. The method for preparing a polyamide composite membrane for salt-tolerant power generation and having a multi-scale heterostructure according to claim 3, wherein the mass fraction of trimesic acid chloride in the second solution is 0.1-0.2 wt%.
  7. 7. The method for producing a polyamide composite membrane for salt-tolerant power generation having a multi-scale hetero structure according to claim 3, wherein the mass fraction of 5,10,15, 20-tetrakis (4-aminophenyl) -21h,23 h-porphyrin in the third solution is 0.03 to 0.1wt%.
  8. 8. The method for preparing a polyamide composite membrane for salt-tolerant power generation having a multi-scale heterostructure according to claim 3, wherein in the step (2), the soaking time of the polyacrylonitrile substrate in the first solution is 3 to 10 minutes, and the soaking time in the second solution is 30 to 100 seconds.
  9. 9. The method for preparing a polyamide composite membrane for salt-tolerant power generation and having a multi-scale heterostructure according to claim 3, wherein in the step (3), the soaking time of the product of the step (2) in the third solution is 5 to 15 minutes, and the soaking time in the second solution is 10 to 30 seconds.
  10. 10. The method for producing a polyamide composite membrane for salt-tolerant power generation having a multi-scale heterostructure according to claim 3, wherein the heating temperature in the step (4) is 50 to 70 ℃, and the time for heat crosslinking is 10 to 30 minutes.

Description

Polyamide composite membrane for salt difference power generation and having multi-scale heterostructure and preparation method thereof Technical Field The application relates to the technical field of films, in particular to a polyamide composite film with a multi-scale heterostructure for salt-tolerant power generation and a preparation method thereof. Background To meet low carbon energy requirements, salinity gradient osmotic energy is of great concern as a "blue energy source". Reverse electrodialysis technology (RED) can achieve ion transport through a permselective membrane, converting gibbs free energy into electrical energy. However, the traditional ion exchange membrane has the defects of insufficient selectivity and high transmission resistance, concentration polarization is generated in ion transmission, the energy conversion efficiency is restricted, and the pore structure is easy to be blocked by biological pollutants and the like. Therefore, the development of highly efficient and stable advanced membrane materials is critical to RED technology practicality. Inspired by the asymmetric nanoscale potassium ion selective channel of the electrified eel, the ion selective membrane with an asymmetric structure becomes a preferable scheme. On the one hand, efficient salinity gradient energy harvesting requires membranes with both high selectivity and high permeability, selective layers with fine nanoporous structures, suitable pore size and pore density, and reduced to nanoscale thickness to reduce transport resistance. At present, researchers mainly develop ordered porous membranes, and the materials with definite structures such as graphene oxide are adopted, but the cost is high, the preparation is complex, the expandability is poor, and the practical application is hindered. On the other hand, the asymmetrically designed ion diode membrane has great potential, and the ion rectification characteristic of the ion diode membrane can realize unidirectional ion transmission and inhibit backflow, so that the power generation efficiency is improved. The heterogeneous channel is formed by integrating sub-channels with different characteristics, but most of the heterogeneous channels are in a bipolar structure, so that the selectivity is reduced, the transmission resistance is increased, and the performance is restricted. Therefore, the control of asymmetric membrane charge space distribution to realize the balance of high rectifying effect, high selectivity and low resistance is still a difficult problem to be solved. Disclosure of Invention Based on this, a polyamide composite membrane having structural stability, high selectivity and low transmission resistance is provided. A polyamide composite membrane for salt-differential power generation and having a multi-scale heterostructure, the polyamide composite membrane comprising a polyacrylonitrile substrate, an intermediate polyamide membrane and a surface polyamide membrane arranged in this order, wherein the intermediate polyamide membrane is obtained by polycondensation of m-phenylenediamine and trimesoyl chloride, the surface polyamide membrane is obtained by polycondensation of 5,10,15, 20-tetra (4-aminophenyl) -21h,23 h-porphyrin and trimesoyl chloride, and the intermediate polyamide membrane and the surface polyamide membrane are mutually permeable at the interface. The structural formula of 5,10,15, 20-tetra (4-aminophenyl) -21H, 23H-porphyrin (hereinafter referred to as porphyrin or TAPP) is shown below: The polyamide composite membrane provided by the application takes the polyacrylonitrile membrane as a substrate, an intermediate layer polyamide membrane and a surface layer polyamide membrane are polymerized on the substrate in situ, an interpenetrating and compatible interface (the interpenetrating is no clear interface and the molecular chains are entangled with each other) is formed between the intermediate layer polyamide membrane and the surface layer polyamide membrane, the structure stability and the low transmission resistance are achieved, meanwhile, the intermediate layer polyamide membrane is a selective layer and has a uniform and negatively charged nanoscale three-dimensional pore structure, the thickness is small, high ion selectivity and permeability can be realized, a positive and negative charge mosaic-shaped charge heterogeneous structure is introduced into the surface layer polyamide membrane through protonizing porphyrin, the loose surface layer polyamide membrane can promote one-way transfer of ions, and the concentration polarization phenomenon is relieved, and meanwhile, the ion selectivity is kept. Meanwhile, as shown in fig. 2, the photo-responsive porphyrin imparts the photo-activation performance to the polyamide composite membrane, namely, the osmotic energy conversion efficiency of the polyamide composite membrane is higher under the illumination condition, and meanwhile, the polyamide composite membrane has the