Nano-magnetic Iron Oxide Preparation Method And Applied Research

Magnetic particles have been proposed for use as biomedical purposes to a large extent for several years. The particles have various opportunities such as improving the quality of magnetic resonance imaging, hyperthermic treatment, site-specific drug targeting delivery, the manipulation of cell membranes, labeled cells separation, magnetic cell sorting, etc. Magnetic material is used as drug carrying agent, drug is entrapment into polymer material, and this magnetic preparation in pharmaceutics are currently one of the most active areas of biomedical research. The drug magnetic colloids can be injected into the body and guided to the targeted area with external magnetic field. Therefore, the techniques could selectively deliver drug molecules to the diseased site by allowing the maximum fraction of the delivered drug molecule to react exclusively with the cancer cells without adverse effects to the normal cells and by allowing preferential distribution of drug to the cancer cells.The preparation conditions of Fe₃O₄ nanoparticles synthesized by co-precipitation and micro emulsion reaction were investigated. The feature of Fe₃O₄ microcrystal was characterized by XRD, IR, TEM, SEM, magnetic property measurements. The results indicate that: 1.The pure Fe₃O₄ nano-particles of the strong magnetic property was synthesized by controlling the ratio of nFe²⁺ :nFe³⁺=1:1 , The temperature of 50℃, little an hour of mixture blend time. 2. The drying temperature influenced the structure and the magnetic property of the Fe₃O₄ nano-particles.3.The average grain diameter of The Fe₃O₄ nano-particles is in the 20 nm by analysis of the TEM picture, and it small the 10nm by calculation of Sherrer formula. Its molar susceptibility (x_m) is 0.9×10^-6(m³.mol^-1 ), molecular magnetic moment is 1.2×10^-22 (J.T^-1). 4. It is feasible that excess Fe²⁺ in solution takes the place of vacuum technique and under nitrogen atmosphere protection during the Fe₃O₄ preparation by co-precipitation and micro emulsion reaction. 5.Fe₃O₄ nanoparticles were synthesized under the influence of polyer. The influence of polyer on the formation of Fe₃O₄ microcrystal was studied in this paper. The XRD show that : The Fe₃O₄ microcrystal is coated by the amorphous of polyer, this polyer protect Fe₃O₄ nanoparticles effectively from oxidizing and improve their anti-oxidation ability greatly. A little of gelatin accelerates the rate of Fe₃O₄ miarocrystal growth, and the amount of gelatin amorphous material increases with an increase of gelatin concentration, so that the magnetic property of samples died down.