New homogeneous and bilayer anion-exchange membranes based on N,N-diallyl-N,N-dimethylammonium chloride and ethyl methacrylate copolymer

Abstract

The paper presents the electrochemical characteristics of a bilayer membrane and a homogeneous anion-exchange membrane based on the new N,N-diallyl-N,N-dimethylammonium chloride and ethyl methacrylate copolymer. The electrochemical behavior and stability under high-intensity electrodialysis conditions were studied using the rotating membrane disk. It has been shown that the casting of a thin layer of an anion-exchange copolymer on the surface of a heterogeneous anion-exchange membrane MA-41 leads to a significant increase in the limiting current (from 4.0 to 8.2 mA/cm2 in 0.01 M NaCl at 100 rpm) and a decrease in the rate of water-splitting reaction at the membrane/solution interface. A decrease in water-splitting rate leads to an increase in the contribution of the electroconvective component to the overlimiting mass transfer, significantly increasing the useful transfer of ions. For membranes formed using the new copolymer, resource tests were carried out for 50 and 400 h at i = 2ilim. Heterocyclic quaternary ammonium bases formed because of N,N-diallyl-N,N-dimethylammonium chloride copolymerization are stable under conditions, while ester fragment of the copolymer undergo hydrolysis. Despite the decrease in the contribution of nonequilibrium electroconvection to the total mass transfer after resource tests, the limiting current on the bilayer and homogeneous membranes does not undergo significant changes.