Cation exchange membranes were prepared based on polyvinyl alcohol (PVA) and polyethersulfone (PES) polymer blends using dimethyl sulfoxide as solvent and phosphotungstic acid (PWA) as functional group agent. The membranes were fabricated by solution casting method. The effects of PVA-to-PES polymer blend ratio and PWA content on the electrochemical ion exchange properties of the prepared membranes, including fixed ion concentration (FIC), membrane potential, permselectivity, surface charge density, transport number and electrical resistance, were studied. The areal electrical resistance at room temperature was reduced by increasing the PES and decreasing the PWA contents of membranes. The results show that the addition of PWA to the membranes provides additional counterion-conducting passages and enhances the FIC, membrane potential, permselectivity and transport number.
