Influence of surface modification with ceria on transport properties of heterogeneous anion exchange MА-41 membranes

Heterogeneous anion-exchange MA-41 membranes were surface modified with cerium oxide, incl. that with a surface functionalized with phosphoric acid groups. Composite membranes were characterized by SEM, TGA, IR spectroscopy, and voltammetry; their conductivity in various ionic forms, anion transfer numbers, and selectivity coefficients for the separation of singly and doubly charged anions during electrodialysis desalination were determined. The modifying layer of cerium oxide practically does not change conductivity of the composite membranes, but increases their monovalent selectivity. E.g., the P(Cl /SO42–) selectivity of the modified MA-41 membrane increases from 0.82 to 1.01, and the P(NO3 /SO42–) selectivity – from 1.38 to 1.60.