Xu Hong, Cui Longlan, Tong Naihu, Gu Hongchen
National Key Laboratory of Nano/Micro Fabrication Technology, Research Institute for Micro/Nano Science and Technology, Shanghai Jiaotong University, Shanghai 200030, PR China.
J Am Chem Soc. 2006 Dec 13;128(49):15582-3. doi: 10.1021/ja066165a.
Monodispersed, hydrophilic, superparamagnetic magnetic nanospheres with a high fraction of magnetite were synthesized by combining modified miniemulsion/emulsion polymerization and sol-gel technique for the first time. The surface of the nanospheres was coated by a silica layer with controlled thickness. Transmission electron microscopy experimental results showed well-proportioned, equal-sized, magnetite/polystyrene (Fe3O4/PS) nanospheres with a thin silica shell. Based on the TGA data, the fraction of magnetite in the Fe3O4/PS nanospheres core was estimated to be 80 wt %. Magnetization measurements indicated that the superparamagnetic nature of the nanospheres had high saturation magnetization of 40 emu/g at 300 K. The procedures of the novel synthesis are described in detail. Also discussed are the mechanisms of the novel combined miniemulsion/emulsion polymerization processes.
首次通过结合改进的微乳液/乳液聚合和溶胶-凝胶技术，合成了具有高比例磁铁矿的单分散、亲水性、超顺磁性磁性纳米球。纳米球表面涂覆有厚度可控的二氧化硅层。透射电子显微镜实验结果表明，形成了比例均匀、尺寸相等、带有薄二氧化硅壳的磁铁矿/聚苯乙烯（Fe3O4/PS）纳米球。根据热重分析（TGA）数据，估计Fe3O4/PS纳米球核心中磁铁矿的比例为80重量%。磁化测量表明，纳米球的超顺磁性在300 K时具有40 emu/g的高饱和磁化强度。详细描述了这种新型合成方法的步骤。还讨论了新型微乳液/乳液聚合组合工艺的机理。
