Modified membrane

Abstract

A multilayered modified membrane and method for making the same, comprising a modified discriminating layer that can have a fouling resistant surface, improved salt rejection, antimicrobial properties, and/or improved solute, and/or small organics rejection as compared to membranes with unmodified discriminating layers.

1 - 35 . (canceled) 
     
     
         36 . A method for making a composite membrane by interfacially polymerizing a polyfunctional amine and a polyfunctional acid halide to form a polyamide discriminating layer upon a porous support, wherein the method is characterized by applying the polyfunctional acid halide to the porous support from a composition comprising an organic solvent and pyridine. 
     
     
         37 . A composite membrane comprising a porous support and a polyamide discriminating layer having an inner side and outer side, the inner side of the discriminating layer in contact with the porous support, and
 wherein the membrane is characterized by the polyamide discriminating layer having a relatively higher concentration of moieties derived from pyridine in a region near the outer side of the discriminating layer as compared with a region near the inner side.   
     
     
         38 . The membrane of  claim 37  wherein the ratio of moieties derived from pyridine in the region near the outer side of the discriminating layer as compared to the region near the inner side of the discriminating layer is approximately 1.5:1.