Fe3O4@SiO2磁性复合微球的制备与表征

Zhang Le, Shao Huiping, Zheng Hang, Ren Xiangyuan

摘要:

本文采用化学共沉淀法制备Fe3O4@SiO2颗粒,在其制备过程中控制Fe3O4@SiO2核的长大时间,加入油酸钠作为表面修饰剂来控制Fe3O4@SiO2核的尺寸,然后加入正硅酸乙酯(TEOS)生成纳米级Fe3O4@SiO2复合纳米粒子和亚微米级Fe3O4@SiO2复合微球。通过X射线衍射、透射电镜、能谱分析和红外光谱分析证实Fe3O4@SiO2颗粒表面包覆有SiO2,并研究了复合粒子的形貌和成分组成,然后进行了磁性能分析,得出Fe3O4@SiO2纳米颗粒、Fe3O4@SiO2复合纳米粒子和亚微米级Fe3O4@SiO2复合微球的饱和磁化强度分别为79.95emu/g、34.85emu/g和61.51emu/g,纳米级的Fe3O4@SiO2和Fe3O4@SiO2复合粒子均表现出超顺磁性,亚微米级复合微球的剩磁和矫顽力都显著增大。

关键词:Fe3O4@SiO2;复合纳米粒子;亚微米级复合微球

Abstract:

In this paper,Fe3O4@SiO2particles were prepared by chemical co-precipitation method. Oil sodium was added when Fe3O4nuclear growing. Then, TEOS was added to prepare Fe3O4@SiO2 composite nanoparticles and magnetic microspheres. The properties of theFe3O4, Fe3O4@SiO2 composite nanoparticles and Fe3O4@SiO2 composite microspheres were tested by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). The magnetic properties were studied by vibrating sample magnetometer (VSM). The result shows that the maximum saturation magnetization of Fe3O4@SiO2 microspheres (34.85emu/g) was lower than that of the Fe3O4 powder (79.55emu/g), but obviously higher thanFe3O4@SiO2 nanoparticles, but the residual magnetism and coercivity force of microspheres were obviously enhanced.

Key words:Fe3O4@SiO2; composite nanoparticles; magnetic microspheres