不同方法制备的Fe_3O_4磁性纳米粒表面性能研究

The surface property investigation of Fe_3O_4 nanoparticles synthesized via different methods

Fe_3O_4磁性纳米粒在工程技术、电子及生物医学等领域具有十分广泛的应用.不同的制备方法及表面改性技术可以得到不同表面特性的纳米粒.而不同的表面特性,其物理和化学性质也存在着巨大差别.因此,深入了解Fe_3O_4磁性纳米粒表面物理性质,以及不同官能基团与粒表面的结合方式等具有十分重要的意义.本论文分别利用X射线光电子能谱(XPS)及X射线衍射分析(XRD)两种重要的材料分析技术,对共沉淀法和高温分解法制备得到的Fe_3O_4纳米粒,以及多巴胺改性后的Fe_3O_4纳米粒表面进行分析,结果表明,共沉淀法制备的Fe_3O_4纳米粒表面无有机成分,可作为水溶性磁流体;而高温分解法制备的Fe_3O_4纳米粒表面有油酸存在,且通过双齿配体共价结合到粒表面;再经多巴胺配体交换改性后,在粒表面形成良好的表面修饰层,但油酸并未全被多巴胺替换.

There are extensive applications for superparamagnetic Fe3O4 nanoparticles in the field of science and nanotechnology, biomedicine. Therefore, magnetite nanoparticles with different surface properties will show different physical and chemical properties. It is very important to investigate the surface physical and chemical properties of Fe3O4 nanoparticles. X-ray photoelectron spectroscopy （XPS） is a very common and effective method to characterize the surface properties of nanoparticles. In this study, XPS and X-ray diffraction （XRD） characterization was introduced to analyze the surface element of Fe3O4 nanoparticles prepared via co-precipitation and high temperature decomposition method. Results showed that the obtained nanoparticles were all magnetite crystals. There is o：eate on the surface of Fe3O4 nanoparticles prepared by high temperature decomposition method. Through the ligand-exchange method, dopamine could be successfully coated on the surface of Fe3O4 nanoparticles through strong covalent bond.