超临界法制备多孔纳米Fe3O4/SiO2复合磁性微球及性能

Preparation and property of nano-porous Fe_3O_4/SiO_2 composited magnetic microspheres by supercritical technique

为了制备具有纳米多孔结构的磁性复合微球,采用正硅酸四乙酯(TEOS)和金属氯盐分别作为SiO2和铁氧体的前驱体,通过溶胶凝胶法制备将Fe3O4纳米颗粒分散于SiO2基体中的Fe3O4/SiO2磁性纳米复合微球,并用超临界干燥法对其进行干燥。利用X线衍射(XRD)、红外光谱(IR)、透射电镜(TEM)和振动试样磁场计(VSM)等分析测试手段对合成的材料进行性能表征。结果表明:复合粒子包覆完好、性能优良、分散性良好,制备颗粒的粒径为30 nm,比饱和磁化强度为84.09 A.m2/kg。

In order to prepare the nano-porous composited magnetic microspheres,nanocomposites with ferrite nanoparticles uniformly dispersed in silica matrix were synthesized by using tetraethylorthosilicate（TEOS） as a precursor of silica and metallic chloride as precursors of ferrite,and dried by supercritical drying.The obtained samples were investigated by X-ray diffraction（XRD）,infrared spectroscopy（IR）,transmission electron microscopy（TEM）,and vibration sample magnetometer（VSM）.Results showed that the encapsulation,the properties,and the dispersion of the proportion of Fe3O4/SiO2 were good.And the particle size and the saturation magnetization were 30 nm and 84.09 A·m2/kg.