Pervaporation separation of ethanol-water mixtures using crosslinked blend membranes

Blend membranes prepared from polyacrylic acid/N-methylol nylon-6 and polyvinyl alcohol/N-methylol nylon-6 are crosslinked with multivalent cation (Al3+) and maleic acid, respectively. The resultant membranes exhibit strong plasticization phenomenon for the pervaporation separation of ethanol-water mixtures. Interesting ''permeation enhancement'' is observed for both crosslinked blend membranes. From the comparison between pervaporation and sorption data, it is suggested that, for hydrophilic membranes, sorption property dominates the membrane performance at feed solutions of higher water content, while diffusion property governs the membrane performance at feed solutions of higher ethanol content.