Pervaporation Properties of Dense Polyamide-6 Membranes in Separation of Water-Ethanol Mixtures

Several dense polyamide-6 membranes were prepared by casting 7 wt% and/or 10 wt% solutions of polymer in trifluoroethanol. The cast membranes were dried at different temperatures from 25 to 80°C. Sorption and pervaporation properties of PA-6 membranes in water-ethanol mixtures were obtained. The data obtained showed that water was preferentially sorbed into the membrane and transported through the membrane; however, the pervaporation selectivity factor αPV was close to unity at higher concentrations. The selectivity parameters in pervaporation were improved for membranes obtained from 10 wt% polymer and dried at higher temperatures.