A new type of interpenetrating polymer network (IPN) pervaporation membranes based on cellulose and synthetic polymers was developed. They were prepared by free-radical polymerization of acrylamide or acrylic acid in the presence (or absence) of the crosslinking agent (allyldextran or N,N'-methylenebisacrylamide) within cellophane films swollen in the reaction mixture. The swelling behavior of these membranes in water-ethanol solutions and their separation characteristics were investigated depending on the polyacrylamide (PAAm) or poly(acrylic acid) (PAA) content in the IPN (C-p) and for ionic cellulose-PAA membranes depending on the degree of neutralization of carboxylic groups and on the type of counterions. IPN membranes were selective over a wide range of ethanol concentration in the feed. The separation factor (alpha) and the permeation rate (P) significantly improved with increasing C-p in IPN membranes, especially for the cellulose-PAA(K+ form) membranes (for 86% EtOH feed at 50 degrees C, and alpha and beta values reached 1500 and 1.6 kg/m(2) h, respectively). The results for ionic and nonionic IPN membranes were compared. The separation characteristics of membranes were in good correlation with their swelling behavior. The alpha values of the membranes depended on the affinity of the IPN polymer chains functional groups for water.