Engineering Novel Thin-Film Composite Membrane for Efficient Forward Osmosis Desalination: Fabrication and Performance Evaluation

Forward osmosis (FO) represents an innovative avenue for energy-efficient water generation from a saline feed. This work presents the development of a thin-film composite (TFC) FO membrane for desalination application. The membrane support layer was fabricated using polyether sulfone (PES) and was modified with poly(2-ethyl-2-oxazoline) (PEOx) and goethite nanoparticles as hydrophilic enhancers. The peak occurring at 1637 cm–1 in FTIR spectra confirmed the presence of PEOx. Moreover, X-ray diffraction spectra of the membrane substrate displayed distinct peaks at 21.40, 33.53, 34.8, and 36.73°, indicative of the presence of geothite nanoparticles. The morphologies of fabricated PES support layers were observed to be significantly porous in scanning electron microscopy images, along with improved porosity and average pore size. The support layer achieved a superhydrophilic loose side (∼0° WCA) and a hydrophilic dense side (∼50.7° WCA), indicating enhanced wetting characteristics. Additionally, the support layer demonstrated the development of a selective polyamide layer. The water permeability coefficient “A” of the TFC-FO membrane was enhanced, and the structural parameter “S” was reduced dramatically. Furthermore, the optimal membrane TFC-M4 exhibited nearly 5.62 and 11.25 LMH flux under FO and PRO modes respectively, with 2 M NaCl draw and deionized water as feed solutions.