Second modification of a polyamide membrane surface

Abstract

The aim of this study was to develop the water flux and antifouling properties of a polyamide (PA) nanofiltration membrane. A nascent PA membrane was prepared with an interfacial polymerization technique and modified with 2,5-diamino benzene sulfonic acid (2,5-DABSA) as a second modification. The effects of the 2,5-DABSA monomer concentration and the modification time on the membrane performance were investigated. The chemical structure, morphology, roughness, hydrophilicity, molecular weight cut off, and antifouling properties of the membranes were characterized by Fourier trans form infrared spectroscopy, scanning electron microscopy, atomic force spectroscopy, contact angle measurement, poly (ethyleneglycol) tracers, and cetyltrimethylammo- niumbromide filtration, respectively. The PA membrane with optimized performance was shown to have a greater than 44% higher water permeate flux with a change in the salt rejection in the order RNa2SO4 >RCa2Cl >RNaCl to RNa2SO4 >RNaCl>RCa2Cl . The improvement of the hydrophilicity led to excellent antifouling properties in the new PA membranes and illustrated a promising and simple method for the fabrication of high performance PA membranes.