PRODUCTION OF LIQUID SEPARATION MEMBRANE EXHIBITING PERMSELECTIVITY TO ETHANOL

摘要

PURPOSE:To obtain the title liq. separation membrane having high strength and exhibiting permselectivity to ethanol by forming a hydrophobic plasma- polymerized membrane on the surface of a polymeric porous membrane substrate. CONSTITUTION:A membrane having =0.5mum mean pore diameter and which is not swollen in an aq. ethanol soln. is used as the porous substrate membrane. Gaseous perfluorocarbon alone or the mixture with a hydrogen-contg. compd. or hydrogen is preferably used as the gaseous monomer for preparing the plasma-polymerized membrane, and the monomer capable of forming a hydrophobic polymerized membrane contg. 15% by the number of fluorine elements can be used. Consequently, the residual stress in the membrane is remarkably reduced, and the stability of the membrane is improved. A separation membrane for pervaporation exhibiting permselectivity to ethanol can be obtained in this way.