Pervaporation with chitosan/hydroxyethylcellulose (CS/HEC) blended membranes

Chitosan/hydroxyethylcellulose (CS/HEC) blended membranes were prepared and crosslinked with a urea-formaldehyde-sulfuric acid mixture. The chemically crosslinking structure of blended membrane was analyzed by IR spectroscopy. The CS/HEC-3/1 and CS/HEC-9/1 blended membranes are appropriate for the dehydration of ethanol-water and isopropanol-water mixtures, respectively. These membranes have high selectivity and promising flux, especially at high alcohol concentration (e.g., J = 112 g m(-2) h(-1), separation factor (alpha(w/e)) = 10,491 for 90 wt.% ethanol solution and J = 175 g m(-2) h(-1), alpha(w/i) = 26091 for 90 wt.% isopropanol solution). Flux increased while the separation factor decreased with increasing water content in the feed. The pervaporation (PV) behavior of the isopropanol-water mixture is similar to that of the ethanol-water mixture. The effect of HEC on the sorption is an important factor for changes in the pervaporation performance of CS/HEC membranes. (C) 2000 Elsevier Science B.V. All rights reserved.