LAUSR

Abstract The introduction of suitable draw solutes is a critical factor in increasing water permeability of a forward osmosis (FO) process. In this study, a branched poly (deep eutectic solvent) was synthesized by surface initiated ring opening polymerization of glycidol on the magnetic core followed by introducing choline chloride as hydrogen bond acceptor to glycerol moieties. Due to the polyionic nature of as-synthesized material, it was expected to represent high osmotic pressure and high water flux. Moreover, the existence of Fe3O4 magnetic nanoparticles as core leads to easy separation of draw solute by an external magnetic field with low energy consumption. The FO performance of the branched poly (deep eutectic solvent)@Fe3O4 as a draw solute was investigated where the water flux of 17.9 L m−2 h−1 (LMH) and the reverse solute flux of 0.12 g m−2 h−1 (gMH) were obtained for 3.5 g L−1 solution. The recyclability of magnetic draw solute was also studied to ensure the FO applicability. Moreover, the brackish water containing 0.2 M and 0.3 M NaCl was also employed as a feed solution to evaluate the capability of branched poly (deep eutectic solvent)@Fe3O4 for the water desalination process.