Synthesis of composite ion-exchange membranes and their electrochemical properties for desalination applications

Abstract

A new type of composite ion-exchange membrane of sulfonated polyethersulfone (sPES) and sulfonated mesoporous silica (SS) was synthesized by dispersing inorganic SS nanoparticles as the fillers in the organic polymer matrix. Physical and electrochemical properties of the composite membranes were investigated in order to evaluate their key parameters as electromembrane candidates in their application in electrodialysis (ED) water purification. The results revealed that incorporating small amounts of SS enhanced the properties of the ion-exchange membranes with negligible influence on their thermal and mechanical properties. Membranes with 0.5 wt% SS were found to have the optimal properties, with good water uptake, ion-exchange capacity (IEC ∼ 1.1 mequiv g⁻¹), transport properties and excellent permselectivity while maintaining excellent mechanical and thermal stability. These newly-developed membranes can be considered as excellent candidates suitable for water desalination by ED.