The effect of different solvents on the performance of zeolite-filled composite pervaporation membranes

The aim of this research is to study effect of different solvents on the membrane morphology and on the performance of zeolite-filled composite pervaporation membranes. PAN (polyacrylonitrile) was used as a base polymer and zeolite 13× (32 wt.%) was used as the filler. The solvents considered were DMF (dimethyl formamide), DMSO (dimethyl sulfoxide), DMAc (dimethyl acedamide) and THF (tetrahydrofuran). The cross-sectional morphology of manufactured membranes shows three layers: a zeolite-free polymer layer, a zeolite-filled polymer layer and a skin layer. However, at the same casting content (5.4% PAN, 2.6% zeolite 13×, 92 wt.% solvent) the ratio of the thickness of these layers to total membrane thickness varies with the solvent used. The most homogeneous zeolite distribution in the polymer network is obtained with solvent DMSO.