Patent ID: 9579608
Date: 2017-02-28
CPC Classifications: B01D,C09D

Claim:
1. A method of making a composite membrane, comprising: (i) applying a chemical mixture (A) to a support membrane to form a treated support membrane, wherein the chemical mixture (A) comprises an aqueous solution of a monomeric polyamine reactant represented by Formula 1: wherein R represents an organic group selected from aliphatic, alicyclic, aromatic, heterocyclic groups and combinations thereof, and z represents an integer of 2 or more; (ii) applying a chemical mixture (B) to the treated support membrane to form a first active layer on the support membrane, wherein the chemical mixture (B) comprises an organic solvent and a monomeric polyfunctional acyl halide reactant represented by Formula 2: wherein R 1 represents an organic group selected from the group containing aliphatic alicyclic, aromatic, heterocyclic groups and combinations thereof, X is selected from the group consisting of fluorine, chlorine, bromine and iodine, and p represents an integer of 2 or more; and (iii) applying a chemical mixture (C) to the first active layer, wherein the chemical mixture (C) comprises a crosslinkable hydrophilic polymer with a backbone comprising repeat units selected from at least one of (meth)acrylate and (meth)acrylamide, and wherein at least one of the repeat units comprises a side chain comprising: an ammonium salt; and a nucleophilic amine group capable of interfacially reacting with an acid halide on or bonded to the first active layer to form a second active layer on the first active layer.