Preparation of porous poly(vinylidene fluoride) membranes with acrylate particles for electrodialysis application

Abstract

Herein we report a simple method to prepare composite ion exchange membranes for electrodialysis application. Composite membranes with enhanced electrochemical properties were obtained from blends of poly(vinylidene fluoride) and free-radically synthesized cross-linked polymer particles having an ion exchange group containing [2-(acryloyloxy) ethyl]trimethylammonium chloride, hydrophobic styrene and cross-linker divinylbenzene. The effect of polymer particles on composite structures, electrochemical properties and desalination performance by electrodialysis (ED) has been investigated. The concentration of polymer particles affects the pore size, porosity, ion exchange capacity (IEC) and water uptake of the composite membrane, which in turn improves the electrochemical property of the composite membrane. Membrane containing 45% acrylate particles was found to possess remarkably good properties with acceptable water uptake (28.6%), IEC (1.01mequivg−1) and transport number (0.97) while maintaining good thermo-mechanical stability. Moreover, the membrane containing 45% acrylate particles exhibited better ED performance result at 15V compared to the commercial membrane Neosepta AMX with 0.93 current efficiency and 7.42kWhkg−1 of salt removed.