Harry F Shuey, Wankei Wan: Asymmetric polyimide reverse osmosis membrane, method for preparation of same and use thereof for organic liquid separations. Exxon Research and Engineering Co, Joseph J Allocca, July 30, 1985: US04532041 (39 worldwide citation)

Asymmetric polyimide reverse osmosis membranes of high flux and selectivity for organic liquid separations are described. These membranes are prepared from undegraded polyimide by dissolving from 14-30 wt. % of the undegraded polymer in a dual solvent system comprising a polymer pro-solvent/anti-sol ...