Fabrication and characterization of a high-flux and antifouling polyethersulfone membrane for dye removal by embedding Fe₃O₄-MDA nanoparticles

Iron oxide (Fe₃O₄) magnetic nanoparticles were successfully synthesized and functionalized with (3-aminopropyl) triethoxysilane (APTES) and melamine-based dendrimer amine (MDA) groups. The resulted nanocomposites and unmodified Fe₃O₄ were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) and then, added to the polyethersulfone (PES) membrane casting solution, during the phase inversion technique in order to improve its hydrophilicity, permeability, and antifouling properties. Surface and cross-sectional morphology of the resulted bare and nanocomposite membranes were characterized by SEM images. The effect of blended nanoparticles on membrane hydrophilicity and performance were determined using water contact angle, pure water flux, BSA solution filtration, and Reactive Green 19 dye solution rejection. The water contact angle for the bare PES, PES-Fe₃O₄ (0.5 wt%), PES-Fe₃O₄-APTES (0.5 wt%), and PES-Fe₃O₄-MDA (0.5 wt%) were measured to be 60.31° 51.08° 44.86° and 37.18° respectively. The pure water flux of the blended PES membranes was enhanced significantly compared to the bare PES due to the higher hydrophilicity. The results of fouling resistance factors including reversible, irreversible, and total fouling showed PES-Fe₃O₄-MDA (0.5 wt%) as the best antifouling membrane. Compared to the all fabricated membranes, PES-Fe₃O₄-MDA (0.5 wt%) showed the highest hydrophilicity, permeability, rejection, and antifouling properties.