Alliedsignal Inc.

Fluid Systems, Inc.

Chinh N Tran

Ratnasamy Somanathan

Adrian C Maldonado

William G Light

Hong C Chu

A thin-film seimpermeable composite membrane employs the reaction product of N-alkyl phenylenediamine or N,N'-dialkyl phenylenediamine and a poly acyl halide, such as trimesoyl chloride. Preferably the membrane is post-treated with an acid solution followed by an aqueous solution of polyvinyl alcohol and a buffer and/or base to improve its physical properties.

Method of making thin-film composite membranes

Thin-film composite membrane

Chlorine-resistant semipermeable membranes which comprise an interfacial polymerized reaction product composite on a porous support backing material may be prepared by contacting a porous support material such as polysulfone with an aqueous solution of an aromatic polyamine, said aqueous solution containing a polyhydric compound and an acid acceptor. The coated support material is then contacted with an organic solvent solution of an aromatic polycarboxylic acid halide for a period of time sufficient to form an interfacial polymerized reaction product on the surface of the support material. The resulting composite is then post treated by washing with an alkaline compound, leaching with sodium bisulfite and treating the leached composite with a polyhydric compound. The resultant membrane composite may be used in separation processes such as the desalination of brackish or sea water, trhe membrane being resistant to attack by chlorine which is present in the water.

Chlorine-resistant semipermeable membranes

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Garden Grove, CA, United States of America

Chinh N Tran