Abstract: Using NMMO-cellulose memberane as matrix and NaOH as precipitant,Fe₃O₄/cellulose composite membranes were prepared by in-situ co-precipitation method.The effects of NaOH concentration on the structure and properties of composite membranes were studied by scanning electron microscopy(SEM),X-ray diffraction(XRD), Fourier transform infrared spectrometer(FT-IR),thermal gravimetric analyzer(TGA) and vibration sample magnetometer(VSM).Results showed that the spherical magnetic Fe₃O₄ nanopartieles were dispersed uniformly and immobilized in the cellulose membranes, and the crystallite size of Fe₃O₄ on the surface of composite membrane increased with NaOH concentration increasing.FT-IR spectra showed that there were good interactions between cellulose and Fe₃O₄ in the membranes.The thermal stability of the composite membrane increased with the increase of NaOH concentration from 1.0 mol/L to 3.0 mol/L,and the residue rate of composite membrane increased from 19.3% to 23.8%.VSM showed that Fe₃O₄/cellulose composite membranes showed good superparamagnetic property,and magnetic properties of the composite membrane improved by increasing the NaOH concentration.

Key words: cellulose memberane, in-situ co-precipitation method, structure and properties