Preparation and electrochemical characterization of mixed matrix heterogeneous cation exchange membranes filled with zeolite nanoparticles: Ionic transport property in desalination

• PVC/zeolite nanoparticles heterogeneous cation exchange membranes were prepared.
• Selectivity was enhanced by increase of additive content and then decreased.
• E-conductivity/flux was obviously increased by increase of additive concentration.
• Membrane selectivity was improved by increase of electrolyte concentration.
• Membranes showed high transport number, selectivity and E-conductivity at pH 7.

In the current research mixed matrix PVC based-co-zeolite nanoparticles heterogeneous cation exchange membranes were prepared by solution casting technique. The effect of used additives and also electrolyte's concentration and pH variations on membrane electrochemical properties was studied. Results showed that membrane water content, membrane potential, transport number and selectivity were improved initially by use of zeolite nanoparticles up to 8 %wt. in the casting solution and then began to decrease by more increase in additive concentration from 8 to 16 %wt. Utilizing zeolite nanoparticles in the casting solution also led to increase in membrane electrical conductivity and ionic flux obviously. Membrane transport number, selectivity and membrane electrical conductivity were all enhanced by increase of electrolyte concentration. Moreover, membranes showed higher transport number/selectivity and lower electrical resistance at pH 7 compared to other pH values. Among the prepared membranes, modified membrane containing 8 %wt. zeolite nanoparticles showed more suitable electrochemical properties compared to others. Also obtained results revealed that modified membranes in this study are comparable with that of other commercial ones. The obtained results are valuable for electro-membrane processes especially electrodialysis for water recovery and treatment.