Nafion-原位合成TiO_2纳米颗粒聚电解质膜的研究

Polymer electrolyte membranes containing Nafion and in situ formed titania nanoparticles

无机纳米颗粒掺杂的全氟磺酸树脂膜,因其较强的保水能力和较好的热稳定性而成为中高温质子交换膜研究的一个重要方向。采用溶胶凝胶法原位水解制得TiO2纳米颗粒,分析了TiO2纳米颗粒在Nafion/TiO2复合膜中的分散状态以及掺杂物对膜的微观结构的影响,研究了复合膜的热稳定性和高温稳定性,并考察了其不同温湿度条件下质子传导性能。结果表明,TiO2纳米颗粒粒径大小在4 nm左右,且在膜内分散均匀;采用正电子湮没技术观察到了掺杂的TiO2纳米颗粒增加了膜内的自由体积。在100℃、低相对湿度条件下,Nafion/TiO2复合膜与均质膜相比,质子传导率有较大的提高,说明Nafion/TiO2复合膜有应用于高温PEMFC膜材料的潜力。

Recast Nafion nanocomposite membranes doped with titania nanoparticles were developed in order to improve the water-retention and proton conductivity at elevated temperature and low relative humidity.Titania nanoparticles with diameters of 3-6 nm were in situ formed in Nafion solution through sol-gel process.The Nafion-titania nanocomposite membranes were formed using a recasting process.It is found that the added titania nanoparticles are well dispersed in the membrane.The positron annihilation life measurements reveals that the free volume inside the composite membrane increases compared to plain Nafion membrane.The formed Nafion-titania nanocomposite membrane also shows the improved proton conductivity at elevated temperature compared to the recast plain Nafion membrane.The potential of Nafion-titania nanocomposite membranes for elevated temperature PEMFC applications was demonstrated in this work.