杂多酸掺杂改性质子交换复合膜的制备及性能

发布时间：2018-04-21 06:02

本文选题：杂多酸 + 质子交换膜　；参考：《安徽理工大学》2014年硕士论文

【摘要】：全氟磺酸质子交换膜是聚合物质子交换膜燃料电池的核心部件,它可以让质子穿过、而水分和气体无法透过。膜的机械强度、耐高温性、耐化学药品性等对于膜的使用寿命具有重要影响。掺杂无机亲水粒子、无机质子导体的质子膜改性对于提高膜的热稳定性和高温保水性等,具有重要意义。以国产东岳集团生产的全氟磺酸离子膜为基体,分别掺杂磷钼酸和硅钨酸、硅钨酸以及二氧化钛、二氧化硅颗粒,利用溶胶-凝胶法和交联法,制备用于燃料电池的磷钼酸/硅钨酸、硅钨酸、TiO2/SiO2复合质子交换膜。分别测定其室温(20℃)、30℃～90℃以及低温-30℃～0℃下的阻抗谱,进而求得不同温度下各复合膜对应的电导率。可以发现,改性之后的复合膜其电导率明显高于原膜。如在90℃时,磷钼酸/硅钨酸复合膜及原膜的电导率分别为27.5×10-6·cm-1和2.70×10-6S·cm-1。且随着温度的升高原膜与复合膜的电导率均呈增大的趋势。如,20℃升到90℃时,二氧化钛/二氧化硅复合膜的电导率从31.2×10-7S·cm-1增加到约为20℃时电导率的4倍。测定扰动电压分别为5mV、10mV、20mV和l00mV时,其对原膜和磷钼酸/硅钨酸复合膜阻抗谱的影响,但发现其变化对阻抗谱的高频半圆影响不大。使用热失重法考察制备的每种复合膜的热稳定性。对于磷钼酸/硅钨酸复合膜,使用Kissinger法、Flynn-Wall-Ozawa法研究其热降解动力学,得到表观活化能E、相关系数r等动力学参数；比较了改性前后质子膜热稳定性的变化,发现当温度超过363.3℃时,复合膜的热稳定性优于原膜,当温度低于363.3℃时,复合膜耐温性能不及原膜。对于硅钨酸、二氧化钛/二氧化硅复合膜,使用Kissinger、 Flynn-Wall-Ozawa、Starink和Friedman法研究其热降解动力学,并使用Achar-Brindley-Sharp、Coats-Redfern以及α-Z(α)法推导出了其可能的热降解机理。硅钨酸复合膜第一阶段的热降解机理为Mampel Power (R1)法则：微分式f(α)=1,积分式g(α)=α。第二阶段的机理函数：f(a)=(1-α)2, g(α)=(1-α)-1;二氧化钛/二氧化硅复合膜的热降解机理亦为二级反应、F2机理。
[Abstract]:Perfluorosulfonic acid proton exchange membrane is the core component of the polymer proton exchange membrane fuel cell. It can let protons pass through, and the water and gas can not be permeated. The mechanical strength, high temperature resistance and chemical resistance of the membrane have an important influence on the life of the membrane. It is of great significance to improve the thermal stability and high temperature water retention of the membrane.
The perfluoro sulfonic acid ion membrane produced by the domestic Dongyue Group was used as the matrix, doped phosphotungstic acid and silicotungstic acid, silicotungstic acid and titanium dioxide, silica particles. The phospho molybdic acid / silicotungstic acid, silicotungstic acid and TiO2/ SiO2 composite proton exchange membrane used in fuel cell were prepared by the sol-gel method and crosslinking method. The room temperature (20 C) and 30 C were measured respectively. The electrical conductivity of the composite films at different temperatures was obtained at 90 C and at low temperature -30 to 0 C. It was found that the conductivity of the modified composite films was significantly higher than that of the original film. At 90, the conductivity of the phospho molybdic acid / silicotungstic acid composite film and the original film were 27.5 * 10-6. Cm-1 and 2.70 x 10-6S. The conductivity of the original film and the composite film increased. For example, the conductivity of the titanium dioxide / silica composite film increased from 31.2 x 10-7S. Cm-1 to about 4 times at about 20 C. The impedance spectra of the membrane and phosphotungstic acid / silicotungstic acid composite membrane were measured at 5mV, 10mV, 20mV and l00mV, respectively. But the change of impedance has little effect on the high frequency semicircle of impedance spectrum.
Thermal stability of each composite membrane prepared by thermal weight loss was investigated. For phospho Molybdate / silicotungstic acid composite membrane, the thermal degradation kinetics was studied by Kissinger method and Flynn-Wall-Ozawa method. The kinetic parameters such as apparent activation energy E, correlation coefficient r were obtained, and the thermal stability of the membrane was compared before and after the modification, and it was found that the temperature was over 363.. At 3 C, the thermal stability of the composite film is better than that of the original film. When the temperature is below 363.3, the temperature resistance of the composite film is less than that of the original film. For silicotungstic acid, titanium dioxide / silica composite membrane, the thermal degradation kinetics of the composite film is studied by Kissinger, Flynn-Wall-Ozawa, Starink and Friedman, and Achar-Brindley-Sharp, Coats-Redfern and alpha -Z (alpha) are used. The mechanism of thermal degradation is deduced by method. The thermal degradation mechanism of the first phase of the composite membrane of silicotungstate is Mampel Power (R1) rule: differential f (alpha) =1, integral g (alpha) = Alpha. The mechanism function of the second stage: F (a) = (1- a) 2, G (alpha) = (1- alpha) -1, and the thermal degradation mechanism of the two oxygen titanium / silica composite membrane is also the two order reaction mechanism.

【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM911.4

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