Fabrication of (polyvinyl chloride/cellulose acetate) electrodialysis heterogeneous cation exchange membrane: Characterization and performance in desalination process

In this research, polyvinylchloride (PVC)/cellulose acetate (CA) blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. CA was employed in membrane fabrication to improve the hydrophilicity of membranes. The effect of blend ratio of polymers binder (PVC to CA) on physico-chemical characteristics of home-made membranes was studied. Scanning optical microscopy (SOM) images showed uniform particles distribution and relatively uniform surfaces for the membranes. Membrane water content and surface hydrophilicity were enhanced with increase of CA blend ratio in casting solution. Membrane ion exchange capacity was also improved slightly with increase of CA ratio in prepared membranes. Membrane fixed ion concentration, membrane potential, charge density, permselectivity, transport number and areal electrical resistance all showed decreasing trends by the increase in CA blend ratio in casting solution. Results revealed that ionic permeability and flux were initially enhanced by the increase of CA concentration up to 20%wt in casting solution and then showed decreasing trend by more CA loading from 20 to 50%wt. These parameters were enhanced again by more increase in CA ratio from 50 to 100%wt in prepared membranes. (C) 2012 Elsevier B.V. All rights reserved.