Hydrophilic surface-grafted poly(tetrafluoroethylene) membranes using in pervaporation dehydration processes

Preparation of hydrophilic poly(tetrafluoroethylene) (PTFE) membranes was performed by means of combined hydrogen plasma and ozone treatment and surface-initiating grafting polymerization. Acrylamide (AAm) and sodium 4-styrenesulfonate (NaSS) were used as monomers in grafting polymerization. Grafted PTFE membrane exhibited high hydrophilicity with a water contact angle of 38° and showed superior performance of pervaporation dehydration for various aqueous solutions of organic compounds. A high permeation flux of 422 g/m2 h and a high separation factor of 4491 were observed with PTFE-g-PSSA membrane in pervaporation dehydration of a 90 wt.% aqueous solution of isopropanol (IPA) at 65 °C. The PTFE-g-PSSA membrane also exhibits advantages of wide application scopes, low temperature-sensitivity, good membrane stability, and operation durability in pervaporation dehydration processes.