Reactive Microporous Composite Membranes

Errede LA, Jefson GB, Langager BA, Olson PE, Ree BR, Reichert ME, Sinclair RA, Stofko JJ (1988) Reactive microporous composite membranes. In Leyden DE, Collins WT (eds), Chemically modified surfaces in science and industry, vol 2 Proceedings of the chemically modified surfaces symposium, Fort Collins, Colorado, June 17-19 1987. Gordon and Breach Science Publishers, New York, p 91... 

Interfdci l Composite Membra.nes, A method of making asymmetric membranes involving interfacial polymerization was developed in the 1960s. This technique was used to produce reverse osmosis membranes with dramatically improved salt rejections and water fluxes compared to those prepared by the Loeb-Sourirajan process (28). In the interfacial polymerization method, an aqueous solution of a reactive prepolymer, such as polyamine, is first deposited in the pores of a microporous support membrane, typically a polysulfone ultrafUtration membrane. The amine-loaded support is then immersed in a water-immiscible solvent solution containing a reactant, for example, a diacid chloride in hexane. The amine and acid chloride then react at the interface of the two solutions to form a densely cross-linked, extremely thin membrane layer. This preparation method is shown schematically in Figure 15. The first membrane made was based on polyethylenimine cross-linked with toluene-2,4-diisocyanate (28). The process was later refined at FilmTec Corporation (29,30) and at UOP (31) in the United States, and at Nitto (32) in Japan. 

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