New PVDF organic-inorganic membranes: The effect of SiO2 nanoparticles content on the transport performance of anion-exchange membranes

Organic-inorganic anion-exchange membranes based on poly(vinylidene fluoride)/SiO2 were prepared and quaternary ammonium groups were introduced by the reaction of the epoxy groups of glycidyl methacrylate with trimethylamine. Various membranes were prepared with different weight fraction of nano-sized SiO2 particles. The effect of silica content on the performance of these anion-exchange membranes was extensively characterized in terms of transport properties (TSP). The hydrophilic nature, swelling and TSP of these anion-exchange membranes were dependent on nanoparticles content in the membrane matrix. Higher TSP values of these membranes were obtained, which increased with increasing silica content. The hydrophilic property of the membranes was improved in presence of silica. Results of the effect of silica content on the membrane conductivity were confirmed by the analysis of phenomenological coefficients using non-equilibrium thermodynamic principles. It can be concluded that these anion-exchange membranes prepared with 2% loading with nanoparticles exhibited better transport properties, which may be used for their application in electro-driven separation or for other electrochemical processes. (C) 2009 Elsevier B.V. All rights reserved.