Abstract: Fe3O4/EDTA nano-composite particles with capability of chelating general metal ions and radio-nuclide metal ions were prepared, and characterized by IR, XRD, XPS, TEM, VSM(vibrating sample magnetometer) and AAS(atomic absorption spectrometer).Chelating agent EDTA was used for the surface modification of Fe3O4 magnetic particles with 20 nm in size. The effects of temperature of preparation process on the crystal form and magnetization, and the capability of the Fe3O4/EDTA nano-composite particles to chelate metal ions were investigated. The results showed that (1) the magnetization of the composite particles prepared at 50～70 ℃ modification condition was equal to that of unmodified Fe3O4 nanometer particles;(2) the stability against oxidization of the Fe3O4/EDTA composite particles was improved owing to the modification of the Fe3O4 particles by EDTA;(3) the composite particles could chelate several general metal ions, such as Cu(Ⅱ)、Ca(Ⅱ)、Mg(Ⅱ) and Ni(Ⅱ),due to that the surface of the Fe3O4/EDTA composite particles was possessed of chelating function groups.

Key words: Composite particles, Magnetism, Fe₃O₄, EDTA, Chelating agent