Thin-film composite membranes with nanocomposite substrate modified with graphene oxide/TiO2 for forward osmosis process

Thin-film composite (TFC) membranes incorporating nanofillers of TiO2 and graphene oxide (GO) in polyethersulfone (PES) substrates were fabricated for forward osmosis (FO) process in the present work. The modified PES substrates by phase inversion and FO membranes by interfacial polymerization were characterized by scanning electron microscopy, atomic force microscopy and contact angle. The synergistic effect of the nanofillers on the transport properties and antifouling performance of the TFC membranes with nanocomposite substrate (NS) was investigated by fouling test. The result showed that the substrates incorporating nanofillers exhibited improved hydrophilicity, greater porosity and higher water flux than the neat samples. Addition of the nanofillers in PES substrates remarkably improved the water permeance of TFC membranes with the drawback of the increase of reverse salt flux. Comparing to single filler, the combination of GO and TiO2 as fillers in the substrate was proved to effectively enhance the antifouling ability of the TFC-NS membranes.