A Novel Composite Nanofiltration Membrane Prepared by Interfacial Polymerization of 2,2′-Bis(1-Hydroxyl-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-methylenedianiline and Trimesoyl Chloride

A novel composite nanofiltration (NF) membrane was prepared by interfacial polymerization of 2,2′-bis(1-hydroxyl-1-trifluoromethyl-2,2,2-trifluoroethyl)-4,4′-methylenedianiline (BHTTM) and trimesoyl chloride (TMC) on polyethersulfone (PES) supporting membrane. Different preparation conditions and NF membrane performances were discussed. The membrane structures of composite NF membranes were characterized by attenuated total reflectance infrared (ATR-IR), scanning electron microscope (SEM), and atomic force microscopy (AFM). The results showed that the NF membrane prepared under the optimum condition exhibited Na₂SO₄ rejection of 85.3% and the water flux of 10.1 l.m^-2.h^-1. The NF membrane was treated by 5000 ppm chlorine solution for 1 h. The salt rejection and water flux of the treated membrane reached to 94.5% and 94.8 l.m^-2.h^-1. The rejection of two NF membranes for inorganic electrolyte solutions decreased in the order of Na₂SO₄, MgSO₄, MgCl₂, and NaCl, which were typical characteristics of negatively charged membranes.