Study Of Preparation And Characterization Of Silicon-oil-based Dysprosium Ferrite Magnetic Liquid

Silicon-oil-based dysprosium ferrite magnetic liquid possesses good performance of heat-resisting, good chemical stability, low viscosity, and low saturated vapor pressure. It is one of valued subjects in the filed of functional material. In the paper, the result of investigation about silicon-oil-based dysprosium ferrite magnetic liquid fabricated by the chemical co-precipitation method was expounded. As the constant quality and molar ratio of reactant, the investigation was done in the impacts about reaction temperature, agitation velocity and reaction time on the formation, shape, particulate diameter of magnetic particles by means of orthogonal experiment. Technological conditions of dysprosium ferrite magnetic particles'preparation were obtained through the sifting from diverse particulate diameters of Fe₃O₄ particles. The influence of the addition of Dy⁺³ on the shape, particulate diameter and magnetization of dysprosium ferrite magnetic particles was studied. The feasible particulate diameter of dysprosium ferrite magnetic particles prepared silicon-oil-based dysprosium ferrite magnetic liquid was sifted from diverse particulate diameters of dysprosium ferrite magnetic particles. The influence of dysprosium ferrite magnetic particles, the surfactant and transition liquid on the magnetism and stability of silicon-oil-based magnetic liquid was researched by means of orthogonal experiment. The optimum ration of dysprosium ferrite magnetic particles, the surfactant and transition liquid was obtained according to saturation magnetizations and light transmittances of magnetic liquids.the silicon-oil-based dysprosium ferrite magnetic liquid with saturation magnetization of 1264Gs and permeation of 2.3% was prepared. The shape and size of dysprosium ferrite magnetic particles was determined by TEM. The Crystal structure and chemical composition of dysprosium ferrite magnetic particles was tested by XRD and XRF, respectively. VSM was used to measure the saturation magnetization of dysprosium ferrite magnetic liquid. The interaction between dysprosium ferrite magnetic particles and the surfactant was analyzed by IR. The result shows that the optimum technological condition to prepare dysprosium ferrite magnetic liquid: reaction temperature 55℃, agitation velocity 900 r/min, reaction time 1.5h, pH 8.0,as the constant quality and molar ratio of reactant. The shape of most dysprosium ferrite magnetic particles is Sphere and their Crystal structure is hexahedron .The size 14.2nm of dysprosium ferrite magnetic particles suit to prepare silicon-oil-based dysprosium ferrite magnetic liquid and the ideal addition of Dy⁺³ is 9.8wt%.The optimum ration of dysprosium ferrite magnetic particles, the surfactant and transition liquid is 1.0(g): 0.3(g):10mL. The interaction between dysprosium ferrite magnetic particulates and the surfactant is the chemical action.