Heterogeneous anion-exchange membrane: Influences of charged binders with crosslinking structure on electrodialytic performance

Abstract

It has practical significance to improve the electrodialytic performance of heterogeneous ion-exchange membrane. In this work, appropriate amount of N,N-dimethylaminoethyl methacrylate (DMAEMA) was added into conventional casting solution composed of poly(vinylchloride), anion-exchange resin particles and N,N-dimethylformamide. After the polymerization of DMAEMA and solvent evaporation, the membrane precursor was formed and then treated by p-xylylene dichloride for the simultaneous quaternization and crosslinking of PDMAEMA. Subsequently, the effects of charged binders with a semi-interpenetrating crosslinking structure on the electrochemical properties of anion-exchange membranes (AEMs) were investigated. Above all, the evolution of chemical composition and morphology changes were recorded by FTIR and SEM, respectively. Moreover, the novel membranes were evaluated from different perspectives, such as Water uptake, Fixed ion concentration, Area electrical resistance, Transport number of counter-ion, Salt permeability coefficient, Limiting current and compared with those of the conventional heterogeneous AEMs with a similar ion-exchange capacity. At last, as-prepared AEMs were applied in simulated electrodialysis experiments. Results showed that the novel membrane-preparing technology made the heterogeneous AEM look and behave more like homogeneous one. Of course, the scheme is also suitable to the hot-pressing technology for the preparation of heterogeneous AEM.