Fouling resistant mixed matrix polyethersulfone membranes blended with magnetic nanoparticles: Study of magnetic field induced casting

Novel mixed matrix membranes were prepared using three different self-synthesized magnetic nanofillers. Neat Fe3O4, polyaniline (PANI) coated Fe3O4 and Fe3O4 coated multi-walled carbon nanotube (MWCNT) were mixed with polyethersulfone (PES) solution in N,N-dimethylacetamide (DMAc). The membranes were prepared using phase inversion method. The effects of casting under magnetic field on the characteristics of the membranes were investigated. The performance of the fabricated membranes was tested in terms of pure water flux and fouling parameters. Magnetic field casting significantly improved water flux of the different mixed matrix membranes around 15%, 29% and 96% for Fe3O4/MWCNT/PES, PANI/Fe3O4/PES and Fe3O4/PES, respectively. This explained by ordering of magnetic nanofillers on the membrane surface casted under the magnetic field of 0.1 Tesla which changed the skin-layer structure. The water contact angle measurement confirmed the superior hydrophilicity of PANI/Fe3O4 mixed membranes. The smooth membrane surface along with high hydrophilicity of the mixed matrix membranes resulted in preferable antifouling properties. Magnetic treated PANI/Fe3O4/PES mixed matrix membrane offered remarkable reusability and durability against fouling by whey proteins. Characterization of synthesized nanofillers and fabricated membranes were carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and water contact angle measurement techniques.