Characterization of poly(vinylchloride) (PVC) based cation exchange membranes prepared with ionic liquids

The aim of this study is to produce poly(vinylchloride) (PVC) based strong acidic cation exchange membranes and to characterize them. Recent studies show hopeful results regarding ionic liquids, which are one of novel alternatives, since they have low volatility, low melting points, thermal stability and nonflammablity. In this research, membranes were prepared by following a heterogeneous method and characterized in physicochemical, morphological and electrochemical ways. Physicochemical characterization consisted of water contents, dry and wet densities, porosities, ion exchange capacities of membranes and isotherm studies. Scanning Electron Microscopy (SEM) analysis was used to perform morphological characterization. Water contents of the membranes were found between 0.3-0.4 while density values were in a range of 0.7-1.2 g/cm3. Porosities were found between 0.2-0.4 and ion exchange capacities changed between 1.2 and 2.8 meq Na+/g-dry. Electrochemical characterization included transport numbers of membranes determined by membrane potential method. They were found around 0.5 for the membranes prepared with dioctyl phthalate (DOP) whereas around 1.0 for the membranes prepared with IL. Diffusivity values of Na+ ions across the membrane were calculated by using Donnan dialysis method and found in order of magnitude -5. © 2011 Nova Science Publishers, Inc. All rights reserved.