Control of zeta potential of polymer layers on selective ion exchange membranes for electrodialysis

Abstract

Abstract The formation of compositions from polymer layers can significantly increase the monovalent selectivity of ion-conducting materials used in membrane separation processes. It is known that the achieved selectivity strongly correlates with the charge of the upper polymer layer determined through its zeta potential. It is of interest to confirm the strict dependence of the zeta potential on the charge of the upper polymer layer for rough commercial membranes. In this work, we studied the zeta potentials of polyallylamine and sodium polystyrene sulfonate adsorbed on heterogeneous membrane in solutions with different charge numbers of the counterion. It is shown that such coatings are characterized by more negative values of zeta potentials in comparison with those known for smooth coatings and that, upon transition to doubly charged counterions, there is no surface recharge.