Preparation and Characterization of Polyfluoroethylene Membranes and Pervaporation / Swelling Properties

The pervaporation is promising in the separation of phenol and water. The modification of membrane material is very important to obtain good selectivity and permeability. Polyfluoroethylene(PVF) and modified PVF membranes with the addition of 0.5wt% graphene were prepared from the solutions containing 2wt%-3wt% polymer. And the structures, crystalline properties and morphologies were characterized by FTIR, TGA, SEM and XRD. The swelling properties and pervaporation (PV) performances for separating 0.5wt% phenol/water mixture were investigated. The effects of feed composition on the flux and the selectivity were studied at 60-80°C. For PVF membranes, the results showed that fluxes increased and selectivity decreased with increasing temperature. The separation factors were from 12.04 to 48.36 at 60-80°C and fluxes were from 2.53 to 1.23 kg·μm·m-2·h-1 at 70-80°C. While for the modified PVF membranes, the fluxes decreased and selectivity increased with increasing temperature. The separation factors were from 4.99 to 10.08 and the fluxes were from 0.83 to 0.47kg·μm·m-2·h-1 at 60-80°C.