Polyoxometalate-cored supramolecular star polymers as a novel crosslinker for graphene oxide-based forward osmosis membranes: Anti-fouling, super hydrophilic and high water permeable

Forward osmosis (FO) process due to its potential in water desalination has attracted considerable attention. Although the FO process possesses numerous privileges like no requirement of external hydraulic pressure, it confronts some challenges. A major challenge is the development of high-performance FO membranes. In this study wa fabricated FO membranes with high water permeability and salt rejection utilizing a pressure-assisted self-assembly method. The supramolecular star polymers consisting of quaternary poly (2-(dimethylamino)ethyl methacrylate) and negatively charged blue lemon polyoxometalate (POM) (PDMAEMA@BL) was embedded into the graphene oxide (GO) active layer to construct physical crosslinking among GO nanosheets. The performance of membranes was analyzed by FO experiment to determination the water flux, reverse salt flux, and selectivity. Modified membranes showed significant augment in water flux in FO mode from 14.93 LMH in control polyamide TFC membrane to 37.26 in P@BL0.8 (0.8 ml of the 25%W/W PDMAEMA@BL). Likewise, the fouling properties of membranes were analyzed using sodium alginate (SA) organic foulant. As results showed, modified membranes performed better against fouling than conventional polyamide TFC membranes.