Anion-exchange with improved alkaline stability

With the increasing use of electrodialysis in the chemical and biochemical process industry and for the treatment of industrial waste waters, the demand for ion-exchange membranes which provide good stability in strong acid or alkaline solutions has drastically increased. Cation-exchange membranes with adequate chemical stability are available today. However, all commercial anion-exchanges are unsatisfactory as far as their alkaline stability is concerned. In this paper the development of anion-exchange membranes with low electrical resistance, high selectivity and good long-term stability in strong alkaline solutions is described. (-z-)