Polymer-modified MXene thin-film nanocomposite membranes for forward osmosis

Abstract Water scarcity demands novel solutions to address the challenges posed by increasing societal needs. This study presents a novel strategy for fabricating MXene-based thin-film nanocomposite forward osmosis (TFN-FO) membranes with enhanced permeability and selectivity, offering a promising advancement in water treatment technologies. The approach involves synthesizing MXene-functionalized polyvinylpyrrolidone (PVP-g-MXene) additives through a facile chemical grafting method, where hydroxyl groups serve as linkers to covalently bond PVP onto the surface of 2D MXene nanosheets. Subsequently, PVP-g-MXene is incorporated into a polyamide (PA) thin film via interfacial polymerization (IP) to produce the innovative TFN-FO membranes. Characterization of MXene and PVP-g-MXene was performed using FT-IR, XRD, TGA, and FE-SEM. The fabricated membranes were analyzed for surface morphology, roughness, and hydrophilicity using FESEM, AFM, and water contact angle (WCA) measurements. The results indicate that incorporating PVP-g-MXene significantly alters the physicochemical properties of the membranes, including morphology, roughness, hydrophilicity, and overall performance during the IP process. All modified membranes demonstrated improved water flux compared to the pristine TFC membrane, with TFN-PgM1 and TFN-PgM2 exhibiting superior selectivity. Notably the representative TFN-PgM2 membrane exhibited a water flux of 18.5 LMH, which is approximately 72% higher than that of the TFC membrane, and demonstrated a Js/Jw ratio of 0.167, indicating an 18.1% improvement in selectivity performance. These findings demonstrate the effectiveness of polymer-modified MXene for the development of high-performance FO membranes.