Preparation of polyamide membranes with improved chlorine resistance by bis-2,6-N,N-(2-hydroxyethyl) diaminotoluene and trimesoyl chloride

Abstract

Polyamide nanofiltration (NF) membranes are very sensitive to oxidant agents, and easy to be degraded by active chlorine solutions attacking. In this paper, bis-2, 6-N, N-(2-hydroxyethyl) diaminotoluene was first introduced into the preparation of polyamide NF membranes. A new type of polyamide composite membrane with improved chlorine resistance was fabricated by bis-2, 6-N, N-(2-hydroxyethyl) diaminotoluene and trimesoyl chloride (TMC) on a polyether sulfone (PES) ultrafiltration support film based on interfacial polymerization (IP). The chemical composition and morphology of polyamide layer were characterized by four kinds of technology. Membrane performances were evaluated by the rejection and water flux of several kinds of solutions (water, NaCl and MgSO4) before and after 200mg−1 NaOCl immersion under different conditions. The results indicate that the polyamide NF membrane has rough membrane morphology and a typical finger-hole structure of cross-section. The properties of the polyamide membranes are strongly dependent on the monomer concentrations and reaction time. The polyamide membrane prepared in this paper showed higher and durable capacity of chlorine resistance.