Plasma deposition of acrylamide onto novel aromatic polyamide membrane for pervaporation

Pervaporation of water/ethanol mixtures through acrylamide-plasma graft-aromatic polyamide, AAm-p-aramide, an aramide membrane on which AAm is grafted by plasma polymerization. was investigated in this work. The surface properties of the AAm-p-aramide membranes were characterized by atomic force microscopy, AFM, and contact angle meter. The effects of degree of grafting, feed composition, feed temperature and surface properties on the pervaporation performances were studied. The separation factor and permeation rate of the AAm-p-aramide membranes were higher than that of the unmodified aramide membrane. Optimum pervaporation was obtained by a AAm-p-aramide membrane with a degree of grafting of 20.5% for a 90 wt% ethanol feed concentration, giving a separation factor of 200 and a permeation rate of 325 g/m(2)h. (C) 2000 Elsevier Science Ltd. All rights reserved.