Study On The Synthesis And Application Of Magnetic Nanoparticles And Magnetic Composite Nanoparticles

In the present work, the preparation, characterization and application of magnetic nano-materials were studied. The main objective of this work is to develop a novel magnetic targeted drug carriers. A series of magnetic composite nano-particles and microspheres were prepared with different surface chemical modification methods. First, the magnetic Fe3O4 and γ-Fe2O3 nano-particles with a mean size of about 20nm were prepared by chemical coprecipitation and sol-gel methods, respectively. The magnetic nano- Fe3O4/chitosan and γ-Fe2O3 /chitosan microspheres were prepared from the above two nano-particles and chitosan with emulsification cross-linking method. The properties of magnetic nano-microspheres were characterized by IR SEM TEM XRD XPS BET VSM AA. It was indicated that the as-prepared two magnetic nano-microspheres was spherical morphology with an average particles size about 350~400nm and the total percentage of nano-particles in the microspheres were all above 35%. The microspheres present favorable properties of sustained release to aspirin, the mangnetic Fe3O4/SiO2 nanoparticles were also prepared by the method of surface modification from TEOS and Fe3O4. It was indicated that the average size of composite particles is about 30nm and the saturation magnetization is 60.5emu/g.Secondly, the magnetic Fe3O4/EDTA and Fe3O4/DTPA composite nanoparticles were prepared successfully by a novel surface in situ modification. The results showed that the chemical bonds were coupled on the surface of nano-magnetic Fe3O4 by EDTA and DTPA on the course of formation of Fe3O4 nano-particles which can effectively enhance the stability of Fe3O4 against oxidization. The as-prepared Fe3O4/EDTA and Fe3O4/DTPA composite nano-particles presented prominent chelation property with metal ions. Furthermore, the magnetic γ-Fe2O3/DTPA composite nano-particles were also prepared. Its chelation property is consistent with that of magnetic Fe3O4/EDTA and Fe3O4/DTPA composite nanoparticles. The above elementary conclusions offer the theoretical basis and experimental foundation for magnetic composite nano-particles applied in radioactive magnetic targeted carriers and sorbents for high-radioactive nucleus scrap.