The role of sulphonated polymer and macrovoid-free structure in the support layer for thin-film composite (TFC) forward osmosis (FO) membranes

► This manuscript introduces a new approach to fabricate thin film composite (TFC) membranes via interfacial polymerization for forward osmosis (FO). ► It is shown that one can design TFC-FO membranes with fully sponge-like structure and anti-fouling characteristics while maintaining a high water flux. ► Not only does the sulphonated material in the substrate of TFC-FO membranes play the key role to create macrovoid-free structure but also induces hydrophilic properties with enhanced water fluxes in the FO process.