Preparation and Investigation of Anion Exchange Membranes Modified with Sulfonated Polyaniline

Abstract

Based on the analysis of the results of sorption experiments and the study of the influence of the oxidant nature at different stages of the preparation of composites, a method has been developed for modifying anion exchange membranes with sulfonated polyaniline by in situ oxidative polymerization of 2-aminobenzenesulfonic acid. The formation of the modifier in the membranes has been proven by analyzing the ATR IR spectra of the samples. The study of the physicochemical and transport properties of composite membranes has shown that the synthesis of the modifier leads to a significant decrease in the exchange capacity from 3.41 to 1.65 mmol/g_dry for the MA-40 membrane and from 0.87 to 0.21 mmol/g_dry for MA-41. In this case, the electrical conductivity of the composite based on the MA-40 membrane increases by 2 to 3 times in sodium chloride solutions and that of the composite based on the MA-41 membrane decreases by a factor of 1.5–2. The current–voltage characteristics of the composite membranes were found to have asymmetry, which confirms the gradient character of the modifier distribution.