Patent ID: 9205383
Filing Date: 2015-12-08
Classification: B01D

Abstract:
1. A polymeric semipermeable membrane comprising a non-cross-linked base polymer having reactive pendant moieties, said base polymer being modified by forming a cross-linked skin onto a surface thereof, said skin being formed by a cross-linking reaction of reactive pendant moieties on said surface with a cross-linking oligomer or another polymer thereby, said base polymer is covalently bonded to said oligomer or another polymer; wherein said base polymer is polyacrylonitrile (PAN) such that at least one portion of said cross-linked skin of said base polymer is covalently bonded to a nanofiltration layer by immersion of said cross-linked skin of said base polymer in polyethylenimine (PEI) and condensate solution comprising cyanuric chloride and sulfanilic acid thereby, said polymeric semipermeable membrane having acid and organic solvent stability; said nanofiltration layer comprises (i) at least one di-, tri- or tetra-halo substituted diazine or triazine-containing monomer, oligomer or polymer, and (ii) at least one multifunctional amine having a molecular weight in the range of 400 to 750,000.