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以溶剂热法制备的高磁饱和强度Fe3O4纳米颗粒为核,正硅酸乙酯(TEOS)为前驱体,采用Stber方法,在乙醇/水溶液中,通过氨水催化水解硅醇盐,制得核壳结构的Fe3O4/SiO2复合磁性微球。对制备的样品的物相结构、形貌和磁性能进行了测试表征。结果表明:制备的Fe3O4/SiO2磁性微球呈球形,粒径分布均一,SiO2壳层圆整光滑,厚度为40~70nm。X射线衍射分析显示,Fe3O4/SiO2磁性微球具有尖锐的Fe3O4特征衍射峰,表明包覆过程没有破坏Fe3O4的晶体结构,其室温下的磁滞回线呈顺磁性,且比饱和磁化强度为30A·m2/kg。此外,对SiO2壳层的包覆机理进行了探究。
The high magnetic saturation strength Fe3O4 nanoparticles prepared by solvothermal method were used as nucleus and tetraethoxysilane (TEOS) as precursor. The Stöber method was used to catalyze the hydrolysis of silicon alkoxide in ammonia / water in ethanol / water solution. Core-shell structure of Fe3O4 / SiO2 composite magnetic microspheres. The phase structure, morphology and magnetic properties of the prepared samples were characterized. The results show that the prepared Fe3O4 / SiO2 magnetic microspheres are spherical with uniform particle size distribution. The SiO2 shell is smooth and round with a thickness of 40-70 nm. X-ray diffraction analysis shows that the Fe3O4 / SiO2 magnetic microspheres have sharp diffraction peak of Fe3O4, indicating that the crystal structure of Fe3O4 does not destroy during the coating process. The hysteresis loop at room temperature is paramagnetic with a specific saturation magnetization of 30A · M2 / kg. In addition, the coating mechanism of SiO2 shell was explored.