Thin-film composite membrane with interlayer decorated metal-organic framework UiO-66 toward enhanced forward osmosis performance

This study reports a new interlayer decoration method for fabricating thin film composite (TFC) forward osmosis (FO) membranes. Metal-organic framework (UiO-66) particles were dispersed at the aqueous-organic interface before interfacial polymerization. Both the TFC membrane without UiO-66 and the conventionally UiO-66 incorporated membrane prepared by interfacial polymerization were fabricated as the control for comparison. Compared with the two control membranes, the interlayer decoration method prepared TFC membrane under an optimized UiO-66 loading showed improved water permeability, salt rejection, and significantly reduced structural parameters. At a much lower UiO-66 loading, with only 5% of the amount used for the conventional incorporation method, the interlayer decorated TFC membrane exhibited significantly enhanced FO water flux and selectivity compared with the conventionally UiO-66 incorporated membrane. Such promising performance is mainly attributed to the unique interlayer UiO-66 decorated structure, in which water molecules can permeate through the channel apertures of UiO-66 nanoparticles, while other hydrated ions can be effectively rejected. This study demonstrates that interlayer decoration by UiO-66 between the polyamide layer and the porous support layer is a promising and economic way to develop new FO membranes with high permeability and selectivity.