Electrochemical characterization of mixed matrix heterogeneous cation exchange membrane modified by aluminum oxide nanoparticles: Mono/bivalent ionic transportation

• PVC/Al2O3 nanoparticles mixed matrix cation exchange membranes were prepared.
• Selectivity was improved by Al2O3 nanoparticles increasing and then decreased.
• Ionic flux was declined by Al2O3 nanoparticles increasing and then enhanced.
• Membranes exhibited lower selectivity for Ba2+ ions compared to Na+ ions.
• Electrical resistance was decreased sharply by Al2O3 nanoparticles increasing.

Polyvinylchloride/aluminum oxide nanoparticles mixed matrix heterogeneous cation exchange membranes were prepared by solution casting technique. The effect of Al2O3 nanoparticles concentration on membrane electrochemical properties was studied. It was found that membrane water content was enhanced by increase of additive concentration in prepared membrane. Increase of aluminum oxide nanoparticles loading ratio in casting solution also caused to decrease in ion exchange capacity. Obtained results revealed that membrane permselectivity and transport number were improved initially in sodium chloride and barium chloride ionic solutions by increase of aluminum oxide nanoparticles concentration up to 2 wt% in prepared membranes and then showed decreasing trend by more increase in additive content. Also membranes exhibited lower selectivity and transport number for bivalent ions in comparison with monovalent ones. Furthermore, membrane ionic permeability and flux were decreased initially by increase in aluminum oxide nanoparticles loading ratio up to 2 wt% and then increased again by more additives concentration. Opposite trend was found for membrane areal electrical resistance. Results showed that modified membranes in this study are comparable with that of other commercial ones.