The pervaporation of ethanol water feeds with polyaniline membranes and blends

Pervaporation experiments with ethanol/water feeds and polyaniline membrane s have been performed. Undoped polyaniline is shown to be highly selective for water over ethanol, leading to selectivities (alpha) > 1,000, although permeation fluxes are low. The mechanism of permselectivity in undoped poly aniline is shown to be controlled by the high diffusivity selectivity for w ater. Hydrochloric acid-doped polyaniline membranes suffer from the effect of HCl-dopants leaching from the membrane into the feed. The use of polymer ic dopants, such as polyamic acid and polyacrylic acid, eliminates this pro blem, and leads to improvements in properties compared to HCl-doped polyani line.