Salt splitting with radiation grafted PVDF anion-exchange membrane

Abstract

A radiation grafted poly(vinylidene fluoride) anion-exchange membrane has been formulated and its behaviour is analysed through the splitting of sodium sulphate by electrohydrolysis. Experiments carried out in a two-compartment membrane electrolysis cell, investigated the influence of flow rate, current density and salt concentration on the performance of the membrane. The different flow conditions had a small influence on current efficiencies, while productivity was significantly greater at higher current densities. The new PVDF material gave acceptable selectivity, low electrical resistance and good chemical, thermal and mechanical stability. A comparison with experiments using cation-exchange membranes demonstrated an inferior performance of the anion-exchange PVDF membrane, in terms of current efficiency and transport properties, despite the lower energy requirements. © 2003 Elsevier Science B.V. All rights reserved.