反相微乳液法制备核壳型磁性SiO_2微球及其表征

Preparation and characterization of core-shell silica magnetic microspheres through reverse microemulsions

目的以FeCl3和FeCl2为水相,以甲苯为油相,以正硅酸乙酯为硅源制备核壳结构的SiO2磁性微球。方法采用反相微乳液法一步法制备出磁性微球,并利用透射电镜、场发射扫描电镜、X射线衍射仪、能谱仪和振动样品磁强计分别对微球的形貌、粒度分布、物相组成、化学成分和磁性能进行表征。结果采用反向微乳液法制备的SiO2磁性微球显示出良好的核壳结构,粒径分布在100~200nm之间,主要物相是无定形的SiO2和立方尖晶石型的Fe3O4,并保持了Fe3O4磁性粒子的超顺磁性。结论采用该方法制备的核壳型磁性SiO2微球性质稳定,是一种优异的生物磁性材料。

Aim To prepare core-shell SiO2 magnetic microspheres with the FeCl3 and FeCl2 as the aqueous phase,toluene as oil phase and tetraethyl orthosilicate as silica source.Methods The magnetic microspheres were synthesized by reverse microemulsions and the transmission electron microscope,field emission scanning electron microscopy,X-ray diffractometer,energy spectrometer and vibrating sample magnetometer were used to characterize the appearance,particle size distribution,phase composition,chemical constituents and magnetic properties of silica magnetic microspheres（MMS）.Results The silica MMS prepared by reverse microemulsions exhibit a superior core-shell structure.The size distribution of the microspheres varies from between 100 nm to 200 nm and the main phase of microspheres is amorphous SiO2 and spinel Fe3O4.The microspheres retain superparamagnetism and can be used as biomaterials.Conclusion The core-shell SiO2 magnetic microspheres prepared by using reverse microemulsions are excellent magnetic biomaterials for its properties are stable.