Robert A Petersen

US Patent:

6162358, Dec 19, 2000

Filed:

Jun 5, 1998

Appl. No.:

9/092768

Inventors:

Norman N. Li - Arlington Heights IL
Mark A. Kuehne - Evanston IL
Robert J. Petersen - Minneapolis MN

Assignee:

NL Chemicals Technologies, Inc. - Mount Prospect IL

International Classification:

B01D 7156

US Classification:

21050038

Abstract:

Reverse osmosis membranes with improved water flux and excellent solute rejection characteristics are formed by interfacial reaction of an essentially monomeric polyamine reactant having an average of at least two amine functional groups with an essentially monomeric amine-reactive reactant having an average of at least 2. 05 acyl halide functional groups, the polymerization reaction being conducted in the presence of a monohydric phenol on the surface of a porous substrate. A specific example is a high flux composite membrane prepared by coating a porous substrate with an aqueous solution containing about 0. 1-20 wt % m-phenylenediamine and 0. 1-9. 9 wt % phenol, and interfacially contacting the coated substrate with a nonaqueous solution of about 0. 01-10 wt % trimesoyl chloride for a time sufficient to form a polyamide coating, followed optionally by one or more washing and drying steps to remove the nonaqueous solvent and most or all of residual unreacted chemicals.