Highly selective proton conductive networks based on chain-end functionalized polymers with perfluorosulfonate side groups
作者:Kui Xu、Chalathorn Chanthad、Michael A. Hickner、Qing Wang
DOI:10.1039/c000044b
日期:——
The copolymers of vinylidene fluoride and perfluoro(4-methyl-3,6-dioxane-7-ene) sulfonyl fluoride containing amino end-groups were synthesized for the first time. The prepared amino-terminated polymers underwent cross-linking reactions with 1,3,5-benzene triisocyanate to form proton conductive networks. The prepared membranes exhibited excellent thermal, hydrolytic and oxidative stabilities. The ion exchange capacity, water uptake, the state of absorbed water, and transport properties of the membranes were found to be highly dependent upon the chemical composition of the copolymers. The cross-linked membranes showed extremely low methanol permeability, while maintaining high proton conductivity at the same order of magnitude as Nafion. This unique transport feature gave rise to exceedingly higher electrochemical selectivity in relation to Nafion. The selectivity characteristics have been rationalized based on the formation of restrained ionic domains and the state of the absorbed water within the membranes.
首次合成了含氨基端基的偏氟乙烯与全氟(4-甲基-3,6-二恶烷-7-烯)磺酰氟的共聚物。制备的氨基封端聚合物与1,3,5-苯三异氰酸酯发生交联反应,形成质子传导网络。所制备的膜表现出优异的热稳定性、水解稳定性和氧化稳定性。发现膜的离子交换容量、吸水率、吸收水的状态和传输性能高度依赖于共聚物的化学组成。交联膜表现出极低的甲醇渗透性,同时保持与 Nafion 相同数量级的高质子电导率。与 Nafion 相比,这种独特的传输特性带来了极高的电化学选择性。基于受限离子域的形成和膜内吸收水的状态,选择性特性已合理化。