Fabrication of Chitosan Membranes with High Flux by Magnetic Alignment of In Situ Generated Fe3O4

Hybrid membranes with in situ generated Fe3O4 were fabricated by combining infiltration and magnetic alignment. Typically, a chitosan (CS) membrane containing iron ions was produced and then immediately immersed in NaOH solution. Fe3O4 was in situ generated when OH− infiltrated into the CS networks, and meanwhile a magnetic field was applied to tune their distribution. The characterization results indicated that Fe3O4 decreased the crystallinity of CS, favored the generation of a free‐volume cavity, and aligned along the magnetic lines. For comparison, hybrid membranes without application of the magnetic field were produced. When used in pervaporation for ethanol dehydration, the hybrid membrane with magnetic alignment exhibited an enhanced flux compared to that without magnetic alignment. Hybrid membranes with aligned Fe3O4 nanoparticles were fabricated by combining infiltration and magnetic alignment method, demonstrating the influence of the alignment of nanoparticles on separation performances. When applied in pervaporation for ethanol dehydration, the hybrid membranes with magnetic alignment exhibited a significantly enhanced flux compared to those without alignment.