SPEEK/PVDF-g-PSSA复合膜中质子扩散的MD模拟研究

为了探究改性磺化聚醚醚酮(SPEEK)基复合质子交换膜的性能,研究了SPEEK和PVDF-g-PSSA(聚苯乙烯磺酸接枝聚偏氟乙烯)共混膜的微观结构和质子传输性能.构建含水量不同的SPEEK/PVDF-g-PSSA共混膜的分子结构模型,采用分子动力学(MD)研究了平衡态模型的微观结构以及质子扩散过程,发现水含量的增加首先会引起水团簇数量的增加,质子电导率随含水量的增加快速升高;在含水量达到饱和(λm=20)时体系的质子电导率为105 mS/cm,与实验测得的96 mS/cm结果相符;当含水量大于λm时,水含量的继续增加会导致磺酸根基团间距增大,质子传导趋于稳定.

Molecular Dynamics Simulation Study on Proton Diffusion in SPEEK/PVDF-g-PSSA Blending Membrane

To explore the performance of based modified sulfonated poly(ether ether ketone) (SPEEK) membrane for proton exchange membrane fuel cells(PEMFC), the microstructure and proton transfer performance of SPEEK/PVDF-g-PSSA blending membrane were studied.The effect of water content on structural and dynamical characteristics of blending membrane was investigated by molecular dynamics(MD) simulation technique.It was observed that as the water content increase, the number of water clusters and proton conductivities first increase rapidly.When the water content reaches saturation (λm=20), the calculated proton conductivity is 105 mS/cm, which was coincident with the results of experiment (96 mS/cm).When the water contentin creases to greater than the saturation value, the distance between sulfur atoms increases, and proton conductivity tends to be stable.