Preparation and properties of anion-exchange membranes for Donnan dialysis of borates were described. It was shown that grafting of polyethyleneimine to surface of Celgard 2500 membrane resulted in preparation of well-permeable membranes. Fluxes of NaCl and Na2SO4 through new membranes were larger than flux of the same salts across commercial FumaTech anion-exchange membranes. However, the collapse of polyethyleneimine chains, generated by higher ionic strength of solution, caused poor selectivity of the grafted membranes and their malfunctioning in the Donnan dialysis process. (C) 2012 Elsevier B.V. All rights reserved.