title: Poly(vinyl alcohol)-based polyelectrolyte pervaporation membranes.
abstract: By modifying poly(vinyl alcohol) (PVA), phosphatic anionic PVA (P-PVA) and quaternary ammonium cationic PVA (C-PVA) with various degrees of substitution (D.S.) were synthesized. The effects of synthesis conditions on the degree of substitution were studied. With these two kinds of materials, polyelectrolyte complexes were formed and their solubilities in water were studied. Pervaporation composite membranes were prepared from P-PVA, C-PVA, and their polyelectrolyte complexes. Some of the membranes showed good separation performance. The polyelectrolyte complex membrane prepared by mixing P-PVA (D.S. 2.3%) and C-PVA (D.S. 2.9%) with weight ratio of 1/1, showed a permeation rate of 378 g/m(2)h and separation factor of 2,250 for dehydration of ethanol/water mixture (ethanol 95.4 wt%) at a feed temperature of 75 degrees C. Some factors that influenced pervaporation performance included type of polyelectrolyte, degree of substitution, ratio of polyanion and polycation, feed temperature, feed concentration, and elapsed time. Solvent resistance of pervaporation composite membranes was also evaluated.
authors.affiliation: Beijing University of Chemical Technology, Beijing, China. sunbenhui@hotmail.com
authors.forename: Benhui
authors.initials: B
authors.lastname: Sun
authors.forename: Jian
authors.initials: J
authors.lastname: Zou
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004573:Electrolytes; D000431:Ethanol / Q000737:chemistry; D006851:Hydrochloric Acid / Q000494:pharmacology; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D011142:Polyvinyl Alcohol / Q000032:analysis*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D004573:Electrolytes; D008567:Membranes, Artificial; D014867:Water; D000431:Ethanol; D011142:Polyvinyl Alcohol; D006851:Hydrochloric Acid