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.