Polyethersulfone/polyamide thin-film nanocomposite membrane decorated by WS2-Cys-UiO-66-(CO2H)2 nanocomposites for forward osmosis

Abstract

The fabrication of some new high-performance WS2-Cys-MOF-incorporated thin-film nanocomposite (TFN) forward osmosis (FO) membranes for use in desalination applications is reported. Herein, WS2-Cys-MOF nanosheets are synthesized through UiO-66-(CO2H)2 grafting on WS2-Cys and integrated into the PA selective layer of TFN membranes. The nanofillers content in the MPD aqueous solution was varied from 0 to 0.25 wt% to acquire the optimal loading and the best FO performance. The presence of polymer-matrix compatible WS2-Cys-MOF in the PA selective layer led to the formation of a defect-free smooth surface with additional channels within this layer, which can boost water flux and fouling resistance of TFN membranes. The TFN-0.1 membrane containing 0.1 wt% WS2-Cys-MOF results in the best FO desalination performance. Compared to the virgin TFC membrane, its water fluxes are almost doubled with a slight increase in the selectivity ∼18% evaluated under AL-FS orientation using 1 M NaCl as the draw solution and deionized water as the feed solution. Moreover, in the fouling test, this optimum TFN-0.1 membrane with a flux decline of 7.63% revealed a ∼1.4-fold enhancement in anti-fouling tendency. Hence, these high-performance WS2-Cys-MOF-incorporated TFN membranes show excellent potential for commercial utilization in the FO-desalination application.