Synthesis Of Water Soluble Superparamagnetic Monodisperse Ferrites Nanostructure

Spinel ferrites show important applications in the area of biomedicine, magnetic fluid, magnetic resonance image and so on. To promote the applications of ferrites in those areas, it is necessary to synthesize monodisperse superparamagnetic nanostructured ferrites particles with high saturation magnetization. In addition, inorganic materials with hollow structure have attract much attention due to their promising applications in the field of drug delivery, catalyst, photonic crystals, Li battery etc. This dissertation works on preparation of monodisperse superparamagnetic nanostructured ferrites particles with high water solubility and high saturation magnetization by a simple one-pot method. Moreover, a ligand assisted dissolution process has been developed for the synthesis of hollow copper tungsten oxide hydroxide. The main points of this dissertation are summarized as follows:1. Monodisperse hollow and core-shell magnetite (Fe3O4) spheres have been prepared by a simple one-pot method based on hydrothermal treatment of FeCl3, citrate, polyacrylamide and urea. The results of control experiments reveal that citrate and polyacrylamide are crucial for the formation of spherical product and the well known Ostwald ripening process is responsible for the transformation from solid spheres to hollow and core-shell spheres. In this synthesis system, citrate serves as a ligand and reducing reagents, polyacrylamide works as a stabilizer, urea provides an alkaline atmosphere for the synthesis system. The hollow and core-shell magnetite spheres are porous and highly water soluble. They exhibit superparamagnetic properties with relatively high saturation magnetization at room temperature.2. Uniform ferrites M1-xFexFe2O4 (M=Zn, Mg, Mn, Ni; 0