Acrylamide plasma-induced polymerization onto expanded poly(tetrafluoroethylene) membrane for aqueous alcohol mixture vapor permeation separation

摘要

To improve the vapor permeation performance of aqueous alcohol mixtures, acrylamide (AAm) plasma activation then post-graft polymerization onto an expanded poly(tetrafluoroethylene) (e-PTFE) membrane, e-PTFE-g-AAm, was synthesized in this study. The surface properties of the e-PTFE-g-AAm membrane were characterized using ATR/ FTIR, SEM, AFM and the water surface contact angle. The degree of grafting increases with increasing polymerization temperature. A maximum value was obtained at 80 degreesC. The water contact angle of the pristine e-PTFE membrane and the e-PTFE-g-AAm membrane with a 21% grafting degree was 109.7degrees and 34.1degrees, respectively. Optimum vapor permeation performance was obtained using an e-PTFE-g-AAm membrane with a 21% grafting degree for a 90 wt.% aqueous ethanol solution, giving a permeate water concentration of 99.4% and a permeation rate of 648 g/m(2) h. (C) 2004 Elsevier Ltd. All rights reserved.