Overcoming LDH–Polyamide Compatibility Limitations in Thin-Film Nanocomposite Forward Osmosis Membranes via Tris-Modified LDHs for Desalination

Incorporating nanomaterials, such as layered double hydroxides (LDHs), into polyamide (PA) layers to develop thin-film nanocomposite (TFN) forward osmosis membranes for efficient desalination has garnered considerable attention. However, designing and fabricating high-quality, well-integrated LDH-based PA selective layers remains a significant challenge. This investigation presents novel Tris-modified LDH (Tris-LDH)-containing PA membranes fabricated through interfacial polymerization, aiming to improve LDH–PA interfacial compatibility and overcome aggregation and defect formation associated with traditional LDH incorporation. The nanosized, highly dispersible Tris-LDHs with exposed amine groups favor their dispersion in the aqueous monomer solution and compatibility with the PA matrix, supporting the formation of a well-integrated LDH/PA selective layer. Furthermore, the hydrophilicity and layered structure of LDHs may contribute to water-transport pathways, while accessible interlayer galleries may provide molecular-sieving effects, promoting water transport while maintaining salt rejection. Tris-LDH incorporation increased the water flux of the optimized TFN-TLDH 2 membrane to 25.18 Lm −2 h −1 (36% higher) and reduced the specific reverse salt flux ( SRSF ) to 0.35 g/L (32% lower) compared with the pristine TFC membrane. In comparison, the TFN-LDH 2 membrane fabricated with conventional MgAl-LDHs exhibited only 25% enhancement in water flux and 9.8% reduction in SRSF . The optimal TFN-TLDH 2 membrane also exhibited outstanding BSA antifouling performance, achieving 92.4% flux recovery and a 22.5% fouling rate, along with sustained performance over 24 h of FO operation. These findings provide an effective strategy to mitigate nanoparticle–polymer compatibility limitations and improve selective layer integrity in LDH-based TFN membranes, thereby enhancing their potential for high-performance FO-based water treatment and desalination.