The Preparation Of Long Life PTFE/Nafion Proton Exchange Composite Membrane And Its Preliminary Performance Research

With the advancement of science and technology and rapid population growth,the global demand for energy is increasing.At present,the supply of energy is mainly based on fossil energy.The use of fossil energy has led to environmental pollution and the shortage of fossil energy.For this reason,the development and application of new energy has become the focus of attention of scientific researchers in various countries.Among them,proton membrane fuel cells have the characteristics of energy saving and environmental protection,high energy efficiency and power density,low temperature fast startup,low thermal radiation and low emissions.With hotspots used.Japan,Europe and other countries have listed fuel cell technology as the focus of new energy technology development.During the development and application process,it was found that the price of proton exchange membrane fuel cells and their later service life severely restricted their large-scale applications.The key factors that affect the price of fuel cells and the later life are the price of proton exchange membranes and the aging of membranes during use.Therefore,it is of great significance to develop low-cost,long-life proton exchange membranes.This paper uses relatively inexpensive PTFE as the matrix to design the surface of the hydrophobic PTFE material to achieve the intermolecular complex between the hydrophobic PTFE matrix and the hydrophilic Nafion.Based on this,the proton exchange membrane is susceptible to damage by hydroxyl radicals during use,and a hydroxyl radical quencher is used to extend the service life of the proton exchange membrane.The specific work is as follows:(1)Surface construction technology of hydrophilic PTFE matrix and preparation of composite proton exchange membrane.The surface of the hydrophobic PTFE membrane substrate was modified by Ti O₂nanoparticles,and the GO sheet was evenly dispersed on the surface of the PTFE/Ti O₂membrane substrate by suction filtration.The contact angle of the PTFE surface was reduced from 139.6°to 44.07°.On this basis,the Nafion/GO/PTFE/Ti O₂composite proton exchange membrane was prepared by the injection of Nafion molecules.The proton conductivity test results of the composite membrane show that the proton conductivity of the composite membrane increases with increasing temperature.When the temperature exceeds 80?,the proton conductivity of the Nafion/GO/PTFE/Ti O₂composite membrane reaches 0.1691 S·cm^-1,whose proton conductivity is higher than 0.1604 S·cm^-1of Nafion117,with a maximum power density of587 m W/cm²,which is close to the power density of Nafion117 membrane,showing that Nafion/GO/PTFE/Ti O₂composite membrane can be used as Great potential for the use of proton exchange membranes.(2)Selection of hydroxyl radical quencher and optimization of its preparation process.This paper selects resveratrol as a radical quencher,uses PM6 semi-empirical quantum computing chemistry method for quantum calculation and loading experiments,and finally selects hydroxypropyl-?-cyclodextrin as the best loading carrier for resveratrol.On this basis,the resveratrol-hydroxypropyl-?-cyclodextrin inclusion complex was prepared by a saturated aqueous solution method,and its inclusion complexes were identified for phase identification,preparation process optimization,and release rate and other related properties.The results of process optimization experiments show that the mass ratio of HP-?-CD and Res is 3:1,the embedding temperature is 40?,and the embedding time is 80 minutes.The best embedding conditions are.The embedding rate reaches 57.42%.It was found through experiments that the release of resveratrol in the composite system conforms to the first-order equation,and the hydroxypropyl-?-cyclodextrin carrier has a certain ability to control the resveratrol.(3)The DPPH method was used to determine the reducing ability of common polyphenols,combined with Fenton's reagent to simulate the degradation of the composite membrane by hydroxyl radicals,and evaluated the ability of the composite membrane to resist the destruction of hydroxyl radicals under the protection of resveratrol.DPPH experiments show that while Res has strong reducing ability and relatively low solubility in water,it is very suitable for use as a proton exchange membrane hydroxyl radical quencher.The experimental results of Fenton reagent simulating hydroxyl radical destruction of proton exchange membrane show that the use of resveratrol as a hydroxyl radical quencher can slow down the chemical degradation rate of proton exchange membrane and greatly increase the life of proton exchange membrane.