Cheng Hou Lee

US Patent:

43225012, Mar 30, 1982

Filed:

Sep 22, 1980

Appl. No.:

6/189414

Inventors:

Cheng H. Lee - Wyckoff NJ
Jay M. S. Henis - Creve Coeur MO

Assignee:

Monsanto Company - St. Louis MO

International Classification:

B01J 4112
C08F 832

US Classification:

521 32

Abstract:

A process is disclosed for quaternizing reactive substituent haloalkyl groups in hollow fiber polymer membranes wherein such haloalkyl groups are reacted with an amine quaternizing agent in the presence of an electrolyte compound and, preferably, in the presence of a cationic quaternary ammonium halide surfactant. In addition, there is disclosed a process of quaternizing the reactive haloalkyl groups in anisotropic hollow fiber polymer membranes by contacting and permeating a solution of an amine quaternizing agent from the surface of the membrane which is to be exposed to a dialysis feed solution.

US Patent:

45279993, Jul 9, 1985

Filed:

Mar 23, 1984

Appl. No.:

6/592519

Inventors:

Cheng H. Lee - Wilmington MA

Assignee:

Abcor, Inc. - Wilmington MA

International Classification:

B01D 5322

US Classification:

55 16

Abstract:

A differential pore-collapsed separation membrane particularly useful as a gas-separation membrane and a method of preparing such differential pore-collapsed membrane, which method comprises treating an asymmetric membrane, while under one-sided constraint, with a treating solution comprising a volatile nonsolvent and a swelling agent and/or a solvent, and drying the treated membrane, to provide for the controlled, differential pore collapse of the small pores of the top skin of the membrane to a smaller pore-size distribution in the membrane generally less than about 10 Angstroms.