Improvement of Water Permeation in Nanofiltration Membranes by Increase of Hydrophilicity in Support Layer

A polysulfone support layer was synthesized for thin film composite (TFC) nanofiltration (NF) membrane by phase inversion in this research. The surface of the polysulfone (psf) support layer was modified by polydopamine (PDA) by self-polymerization. The thin film nanocomposite (TFN) membranes were prepared by interfacial polymerization reaction using trimesoylchloride (TMC) and m-phenylenediamine (MPD) as the monomers on a modified polysulfone substrate. Graphene oxide (GO) nanosheets were added to the aqueous solution to improve the NF hydrophilicity and the water flux. The water flux and salt rejection of TFC and TFN nanofiltration membranes were measured in a dead-end stirred cell filtration device. The TFN-PDA membrane showed higher pure water flux than TFN membrane. The addition of PDA and GO in TFN membrane increased the water flux from 6 to 14.5 L/m2h in polyamide(PA)/GO and 7 to 15L/m2h in PDA-PA/GO. The rejection in TFN-PDA was decreased from 97% to 80%.

Keywords:

Nanofiltration , Thin film Nanocomposite Membrane , Polydopamine , Graphene oxide