Study Of Preparation And Properties On Fe₃O₄ Magnetic Nanoparticles And Magnetic Fluids

Magnetic fluids is a kind of stable colloidal solution formed from magnetic nanoparticles, regularly scattering in the carrier, coated by surfactant. It has both the magnetic properties of solid-state and the mobility of liquid-state. Magnetic fluids can be broad applied to modern technologies, such as magnetic seals,dampers, actuators, sensors and magnetic shielding, etc. The current research efforts have been focused on the biomedical, especially applied in targeted drug delivery systems which been called "targeting missile" , showing remarkable potential applications in cancer therapeutic field.In the research of Fe3O4 magnetic fluids, it is important to prepare magnetic nanoparticles and ensure the stable suspending of FeA magnetic fluids. In the same time, For biomedical clinical applications, magnetic fluids must be biocompatible. In view of this situation, the objectives of the current work were to develop a convenient method to prepare magnetic fluids with biocompatibility surfactants and study the effect of different conditions on the stability of the magnetic fluids. The thesis major explored in the following aspects: a. Through the analysis of preparation mechanism of nanoparticles, we adopted the improved chemical co- precipitation method to prepare magnetic Fe3O4 nanoparticles. Under the best preparation condition, we got the Fe3O4 nanoparticles with sizes 8-10nm, coatedby surfactants of oleate and Polysorbate 80(Tween-80), which shown good properties of granularity distribution , anti-conglomerates anti-oxidizing and saturation magnetization. The magnetic Fe3O4 nanoparticles can be used in the magnetic fluids.b. The result of the test shown that the amount, the percentage and the sorts of surfactants play an important role on the preparation of magnetic Fe3O4 nanoparticles and the suspending stability of magnetic fluids. Coated by 3% oleate solution, we got the stability water-based magnetic fluids. But we could not get the stability water-based biocompatibility magnetic fluids, simply coated with polyethyleneglycol (PEG) and polysorbate - 80 (Tween-80).c. The methodey testing the suspending percentage of Fe3O4 to valuate the qualities of magnetic Fe3O4nanoparticles and magnetic Fe3O4 fluids is simply and effective. The result of tests shown the stability of suspending of magnetic FeA fluids could provide useful information on the nature of magnetic fluids under definite conditions, vice versa can use to improve the method of preparation of magnetic Fe3O4 fluids.