PERVAPORATION SEPARATION MEMBRANE

PURPOSE:To obtain a membrane having high separation coefficient as well as transmission fluxes and good durability by making conductive polymer exist on at least one surface of a cation-exchange membrane. CONSTITUTION:As a cation-exchange resin membrane, a membrane of hydrocarbon-type, fluoro-type, and perfluorocarbon-type polymers is used. A conductive polymer of pyrrole, its derivatives, aniline, its derivatives polymerized by chemical oxidation is made to exit on at least one surface of the cation- exchange membrane. If necessary, the conductive polymer may be doped with a suitable cation or anion. To obtain the membrane, a method wherein the conductive polymer is dissolved in some solvent and a thin film is formed by pouring or applying or spraying the solution to a cation-exchange membrane and drying it is applied. In this way, a membrane having high separation coefficient as well as transmission fluxes and excellent durability for a long period is obtained.