Preparation And Performance Of Fe₃O₄ Based Photo-Thermal Composites

Photo-thermal therapy (PTT) is defined as a minimally invasive treatment, which using the light absorber, achieving the convert of nearly infrared light energy to heat energy, and finally "kill" the cancer cells. In recent years, this therapeutic method has gained a great deal of attention due to the effectiveness of curing cancer cells, but not damage the surrounding healthy tissue. Thoses materials which have high photo-thermal convert efficiency were needed to explore to improving the photo-thermal convert effect. Owing to the good biocompatibility and magnetism, Fe3O4 was used widely in the area of nuclear magnetic resonance (NMR) imaging, biological detection and disease diagnosis. If combing this Fe3O4 with material owing high photo-thermal convert effect, we could get a kind of light absorber, which have the properties of targeted and high photo-thermal convert effect. The main points of the dissertations are summarized as follows:Fe3O4 nano-microspheres were prepared by the solvothermal process according to changing the difference reaction times, FeCl3·6H2O and ethylene glycol were used as raw materials. HAuCl4 was reduced by NaBH4, then combined with Fe3O4 nano-microspheres, finally Fe3O4/Au nanocomposite were obtained. After characterization and property test, the results showed that this Fe3O4/Au nanocomposite had the properties of photo-thermal convert and SERS.Iron oxide (Fe3O4 and α-Fe2O3), were prepared by the modified solvothermal method, utilizing Fe(acac)3 and N-methyl-2-pyrrolidone as raw material and solvent, respectively. Different reaction temperatures and times were explored as the influence factors to the structure and morphology of final products. According to reducing HAuCl4, iron oxide and Au nanoparticles were combined together, and Fe3O4/Au and α-Fe2O3/Au nanocomposites were acquired finally. Experimental results showed that in the process of preparing Fe3O4 monodispersed nanoparticles, in-situ modification of Fe3O4 could harvest the Fe3O4/Au products with a high Au content. After performance tests, at a level, the two materials both had the properties of photo-thermal convert and SERS.Fe3O4 seed nanoparticles with better water-soluble were prepared by thermal decomposition process, using Fe(acac)3 as raw material and N-methyl-2-pyrrolidone as solvent, which the particle sizes were smaller than 5 nm. Reflux time was changed to control the growth of Fe3O4 seed nanoparticles, and in the end, the product diameter of Fe3O4 was at the range of 10～20 nm. After modify with SUDEI, the magnetic particles were combined with Au nanoparticles and Fe3O4/Au nanocomposites were achieved finally. The Fe3O4/Au nanocomposites prepared by this process had a characteristic that the particles of Au nanoparticles were larger than Fe3O4. Fe3O4/C nanocomposites were prepared by a one-step process, at the time of decompositing Fe(acac)3 and carbon nanotubes were added into the reaction solution. After characterization and property test, the results showed that these composites all had photo-thermal property, and had a certain application value in the area of PTT.