Electrochemical and mechanical stability of ion-exchange membranes in alkaline solution

This paper focuses on the transport and mechanical properties of ion-exchange membranes (IEMs) in an aqueous NaOH solution. Heterogeneous IEMs based on styrene–divinylbenzene and polyethylene reinforced with polyester (PES) or polyamide (PAD) fabric were studied. The IEMs were exposed to a 5% NaOH solution for 30 and 90 days and the changes in electrochemical resistance, transport number and permselectivity were evaluated. Moreover, the structure of the IEMs was observed after exposure and their mechanical properties were evaluated. The results show that NaOH solution has the most damaging effect, especially to PES cloth and the membrane as whole, mainly due to dimensional changes. Furthermore, changes in electrochemical resistance were observed.