Hydroxide Ion Highway Constructed by Orderly Aligned Quaternary Ammonium Groups in Anion Exchange Membranes

Self-assembly of Gemini surfactants (maleic alkylene group diethylbis [octyl dimethyl bromide], abbreviated as G(16-2-16)) were used to form reversed micelles by introducing sodium salicylate (NaSal) into chloroform solution of PSF (polysulfone). The rheological measurements indicated that micelles had been formed. The internal surface of micelles were full of orderly arranged quaternary ammonium (QA) groups as cationic active sites. Then we characterized the composite membranes which were introduced micelles, it turned out that, the OH- conductivity in presence of NaSal was higher than the absence one, indicating that the formation of reversed micelles arranged the cationic active sites more orderly, resulted in improving the anionic conductivity by 40-80%, especially under low values of water uptake and ion exchange capacity condition, which provided a kind of approach of enhancing OH- migration efficiency without sacrificing its dimensional stability and mechanical properties. The composite membranes also showed an outstanding thermal stability. And 240 h high temperature alkaline-stable test (10 M NaOH) revealed that the largest decline of OH- conductivity was only round about 4%, which showed excellent alkaline resistance stability. (C) 2017 The Electrochemical Society. All rights reserved.