Polypyrrole was incorporated into the ionic clusters of Nafion(R) to reduce the free volume of the membrane. The Nafion(R)-polypyrrole composite film consisted of 8.9 wt.% of polypyrrole. The presence of polypyrrole decreased the percent sorption capacity of methanol from 38 to 19 g/g membrane and ethanol from 36 to 30 g/g membrane. The composite membrane was also swollen to a lesser degree in alcohol solutions. Alcohol flux measurements were carried out in perstraction mode at 80 degreesC, with the feed concentrations ranging from 1 to 4 M. Fluxes observed with the composite films were two to three times lower than those of Nafion(R). (C) 2003 Elsevier B.V. All rights reserved.