Preparation And Rheological Property Of Magnetic Fluid

The magnetic property of Fe3O4 nanoparticles was studied systematically. Magnetic fluid (MF) based on Fe3O4 nanoparticles was prepared using different dispersants. The rheological property and biocompatibility of the MF were investigated.(1) The effects of different conditions on the synthesized Fe3O4 nanoparticles were investigated. On this basis, a new route was produced to synthesize Fe3O4 nanoparticles with higher saturation magnetization, in which hydrazine hydrate (N2H4·H2O) was employed to substitute inert gases and continuous microwave irradiation was utilized to heat the reaction. The results demonstrate that spherical Fe3O4 nanoparticles with a diameter of 10 nm were systhesized, and the as-synthesized Fe3O4 nanoparticles display higher saturation magnetization (84.83 emu/g).(2) To preserve the magnetism of Fe3O4 nanoparticles at relatively higher temperature, Fe3O4/BaSO4 multi-core/shell particles were synthesized via fractional precipitation. The magnetism of as-synthesized particles did not vanish until 750oC. Besides, in order to resolve the contradiction of high filling content and low mechanical strength in magnetic composites, Fe3O4 nanoparticles were encapsulated into multi-walled carbon nanotubes. The saturation magnetization of the Fe3O4/MWCNTs composites is 13.15 emu/g.(3) Water-based MF were prepared via mechanical mixing method using different surfactants. The solid content, stability, magnetic and rheological property of such MF were investigated. The results show that dextran-stabilized MF has the highest solid content, best stability and strongest magnetism. In order to positively charge the Fe3O4 nanoparticles, amino functionalized Fe3O4 nanoparticles were prepared via the reaction between -OH from Fe3O4 nanoparticles and -OC2H5 from KH550. Zeta potential measurement demonstrates that MF containing amino functionalized Fe3O4 nanoparticles is positively charged. The compatibility between dextran stabilized MF and blood was studied. The results show that dextran stabilized MF is well compatible with blood.