Modified composite cation exchange membrane with enhanced stability and electrochemical performance

Abstract

Herein, we elaborated on the feasibility of coupling polyvinyl chloride with tin aluminium molybdophosphate to form composite membranes that facilitate enhanced electro-transport properties. Additionally, the effect of appropriate material selection on attaining excellent stability and selectivity of a membrane was investigated, and the membrane with 25% polymer had the best results in terms of improved ion exchange capacity, water uptake, porosity, membrane potential, and chemical and thermal stabilities. The electrochemical properties of the membrane that had the most stable polymer ratio were evaluated according to the membrane potential and fixed charge density measurements using different 1:1 ratios of electrolytes with various concentrations (1 M to 0.01 M). The membrane potential, transport number, and mobility ratio of the electrolytes from the highest to lowest were NaCl > KCl > NaNO3 > KNO3.The measured membrane potentials closely agreed with the theoretical predictions from a mathematical model called the Toerell, Maeyer, and Siever (TMS) model, confirming efficiency and selectivity.