Tuning interfacial compatibility of LDH nanoparticles and polyamide membranes for improving forward osmosis performance

A thin-film nanocomposite (TFN) polyamide (PA) membrane is an emerging class of composite membrane that incorporates nanoparticles (NPs) into the PA layer via interfacial polymerization. However, poor interfacial compatibility between the NPs and the PA matrix often compromises desalination selectivity. Here, we fabricated TFN membranes containing layered double hydroxide (LDH) NPs intercalated with butyrate (NaB) ions to improve interfacial compatibility with the PA layer. The prepared TFN NaB series membranes demonstrated superior interfacial interaction, resulting in significantly improved water permeance (up to 5.23 L m −2  h −1  bar −1 ) and moderate NaCl rejection (up to 94 %) in the reverse osmosis. Additionally, the TFN NaB series membranes provided the higher water (48.74 L m −2  h −1 in PRO mode) and ethanol (3.94 L m −2  h −1 ) fluxes in forward osmosis (FO) and organic solvent forward osmosis (OSFO) systems, demonstrating their enhanced versatility for osmotic filtration performance. This work addressed the limitations of LDH-based TFN membranes and highlights the significance of anion engineering within LDH NPs. Overall, this work offers a promising strategy to improve permeability and desalination performance of TFN membranes for FO and OSFO applications.