Transport properties of hydroxide and proton conducting membranes
Transport properties of hydroxide and proton conducting membranes
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DOI：
10.1021/cm703263n
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发表时间：
2008-04-08
影响因子：
8.6
通讯作者：
Cornelius, Chris J.
中科院分区：
文献类型：
--
作者：
Hibbs, Michael R.;Hickner, Michael Ai;Cornelius, Chris J.
氢氧化物阴离子传导固体聚合物膜，也称为阴离子交换膜，正在成为电化学技术的重要材料，并且在碱性燃料电池的重新兴趣的刺激下，该领域的活动正在经历复苏。固体聚合物阴离子交换膜能够在诸如燃料电池和电解槽的装置中实现碱性电化学，并且用作质子交换膜的对应物，其中存在大量文献。尽管它们看起来很重要，但在碱性交换膜中传输的细节还没有被彻底探索。在这项工作中，一个氯甲基化的聚合物与聚砜骨架的合成。进行1H-1 NMR光谱以确定氯甲基含量及其在聚合物结构上的位置。将氯甲基化的聚合物溶液流延以形成透明的credible膜，并且随后将这些膜浸泡在三甲基胺水溶液中得到苄基三甲基铵基团。所得阴离子交换膜在水中溶胀，并根据其离子交换容量显示不同程度的离子电导率。在阴离子交换膜中的水的流动性大于以前研究的质子交换膜，然而，在这些新材料的传输性能低于可能已经从水的行为预期。这种比较提供了一些见解，未来的阴离子交换膜的设计目标。
Hydroxide anion conducting solid polymer membranes, also termed anion exchange membranes, are becoming important materials for electrochemical technology, and activity in this field, spurred by renewed interest in alkaline fuel cells, is experiencing a resurgence. Solid polymer anion exchange membranes enable alkaline electrochemistry in devices such as fuel cells and electrolyzers and serve as a counterpoint to proton exchange membranes, of which there is a large body of literature. For their seeming importance, the details of transport in alkaline exchange membranes has not been explored thoroughly. In this work, a chloromethylated polymer with a polysulfone backbone was synthesized. H-1 NMR spectroscopy was performed to determine the chloromethyl content and its position on the polymer structure. The chloromethylated polymer was solution cast to form clear, creasable films, and subsequent soaking of these films in aqueous trimethylamine gave benzyltrimethylammonium groups. The resulting anion exchange membranes swell in water and show varying degrees of ionic conductivity depending on their ion exchange capacity. The water mobility in the anion exchange membranes was greater than in previously studied proton exchange membranes; however, the transport properties in these new materials were lower than what might have been expected from the water behavior. This comparison gives some insight as to future anion exchange membrane design objectives.