The Preparation Of Magnetic Fluid And Its Application In Hyperthermia

Fe₃O₄ magnetic nanoparticles and magnetic fluid are very important magnetic nanomaterials. In this paper, the preparation of Fe₃O₄ magnetic nanoparticles and magnetic fluid was systematically investigated.(1) The traditional chemical co-precipitation was modified. The Fe₃O₄ nanoparticles were prepared without the protection of inert gas, which simplify the operation process. The reaction conditions such as molar ratio of iron ion, reaction temperature and reaction time were studied and the optimal condition was determined. To improve the crystal structure and tune the particle size, the Fe₃O₄ nanoparticles were treated with ultrasonic. The effect of the ultrasonic on the particle size, morphology, crystal structure and magnetic properties was investigated. To tune the particle size, the Fe₃O₄ nanoparticles were treated with hydrothermal condition. The effect of reaction temperature, time and pH value on the Fe₃O₄ nanoparticle was investigated. The results indicated that the pH value has great effect on the morphology of the Fe₃O₄ nanoparticle. At low pH, it is favorable to get larger spherical nanoparticles. While at high pH, octahedral nanoparticles were obtained.(2) Fe₃O₄ nanoparticles were prepared by modified co-precipitation method without of the protection of inert gas. OL was used to modify the Fe₃O₄ nanoparticles to improve the compatibility between the Fe₃O₄ nanoparticles and the carried liquid. Finally, stable conducting oil based magnetic fluid was obtained. The optimal preparation conditions such as reaction temperature, time and OL dosage were determined. The particle morphology, crystal structure and magnetic properties were investigated. The interaction between the Fe₃O₄ nanoparticles and OL was characterized using Fourier transform infrared (FT-IR) spectroscopy. The stability and magnetic properties were characterized using magnetic balance.(3) Silicon oil based magnetic fluid was prepared using TE and silicon surfactant EY as modifier. To improve the interaction between the Fe₃O₄ nanoparticles and the silicon surfactant, The Fe₃O₄ nanoparticles were firstly coated with a SiO2 layer by the hydrolysis of TE. Then the hydroxyl groups on the surface of the Fe₃O₄ nanoparticles were easily to react with the ethoxy groups on the silicon surfactant. The optimal amount of TE and silicon surfactant EY was determined. The properties of the Fe₃O₄ nanoparticles and the silicon oil based magnetic fluid were investigated. The results indicated that the Fe₃O₄ nanoparticles had well crystal structure, uniform particle size and high saturation magnetization. The silicon oil based magnetic fluid had strong magnetism, high stability and sheer thinning property.(4) KT which has good biocompatibility was used to modify the Fe₃O₄ nanoparticles and water-based magnetic fluid was prepared. The magnetic fluid was characterized by a series of methods. And the heating effect of the magnetic fluid in alternate current magnetic field was investigated. The effect of magnetic field strength, concentration of the magnetic fluid and the modification on the heating effect was studied.