Ion transport behavior in diffusion layer of new designed ion exchange-mosaic composite polymer membrane

Abstract

New designed ion exchange-mosaic composite polymer membrane (MM/AEM) was proposed in this study. The new membrane was made from anionic exchange polymer gel (AEM) that coated onto mosaic polymer membrane (MM) to form MM/AEM polymer composite membrane system. Also, AEM membrane without mosaic membrane layer was used as reference commercial ion exchange membrane. The electrochemical properties of new designed composite polymer membrane system (MM/AEM) and non-composite one (AEM) were investigated by chronopotentiometry measurements (CP) and current–voltage curves ( I– V). In the presence of KCl solution, the limiting current density of new designed composite MM/AEM was higher than that of commerical AEM. In other words, at the same current density, the transition time of composite MM/AEM was shorter than that of commercial AEM, and also diffusion layer thickness ( δ), of composite MM/AEM was smaller than that of commercial AEM. It can be concluded that the new designed composite anionic exchange polymer membrane provides relatively good ion transport and other good membrane properties. In addition, the production of this new designed composite polymer membrane can be used in industry, like electrodialysis, as an alternative membrane instead of the commercial ion exchange membrane, which suffers from low limiting current density.