PEGylation and incorporation of triazine ring into thin film composite reverse osmosis membranes for enhancement of anti-organic and anti-biofouling properties

Abstract

An approach for the simultaneous enhancement of anti-organic and anti-biofouling properties of polyamide thin film composite (TFC) reverse osmosis (RO) membranes is reported. In situ incorporation of both triazine ring and polyethylene glycol (PEG) into the polyamide network yielded such TFC membranes. The polyamide active layer was fabricated on top of polysulfone support membrane via interfacial polymerization (IFP) between conventionally used trimesoyl chloride (TMC) and mixture of m-phenylenediamine (MPD), melamine and MPD-terminated PEG (MeO-PEG-MPD). The membrane prepared by MPD/melamine/MeO-PEG-MPD exhibited superior overall antifouling properties compared to membrane prepared by MPD/melamine or MPD as sole amine monomer. It turned out that the incorporated PEG enhances anti-organic fouling property and reduces the bacterial adhesion whereas triazine ring only lowers the growth of bacteria on TFC membrane surface. The membrane containing both triazine ring and PEG exhibited pronounced effect on reducing bacterial adhesion than that of membrane containing triazine alone. TFC membrane prepared by IFP between TMC (0.125%, w/v) and mixture of MPD+melamine+MeO-PEG-MPD (MPD:melamine:MeO-PEG-MPD=1:1:0.5 w/w) exhibited enhanced overall antifouling property with permeate flux ca. 38Lm−2h−1 and NaCl rejection ca. 93% from feed solution (containing 2000ppm NaCl) at applied pressure 1.4MPa.