Composite membrane for reverse osmosis

摘要

A composite lumen-side feed reverse osmosis membrane and its preparation are disclosed, the membrane comprising a polymeric microporous-walled hollow fiber support with an interfacially-polymerized ultrathin semipermeable salt-rejecting layer engrafted on the lumen or bore of the hollow fiber support, the support having walls that are substantially completely free of finger-like voids in excess of about 5 microns in the area of the wall adjacent the lumen. The preparation of the support comprises coaxially spin-casting (1) a fiber-forming solution containing a pore-forming material with (2) a lumen-forming fluid comprising from about 50 to about 70 vol % organic solvent in water.