中文摘要：

采用化学共沉淀法合成了超顺磁Fe3O4纳米粒子,并采用油酸和油酸钠对其表面进行修饰,制备了可稳定分散于水中的磁流体。以该磁流体为种子,通过一步乳液聚合制备了表面带有功能化羧基的Fe3O4-聚甲基丙烯酸甲酯复合纳米微球（Fe3O4-PMMA）。利用动态光散射、透射电镜观察、傅里叶红外光谱、热失重分析、振动样品磁强计测试等手段表征了复合微球的尺寸、形态、结构、组成和磁性能。结果表明,复合微球的平均直径约120nm,表面带有羧基功能基团,在室温下具有超顺磁性和较高的饱和磁化强度。

英文摘要：

Superparamagnetic Fe3O4 nanoparticles were first synthesized by chemical co precipitalion method. Then, the surfaces of Fe3O4 nanoparticles were successively modified with oleic acid and sodium oleate to obtain stable magnetic fluid in water. Finally, Fe3O4-poly（methyl methacrylate） （PMMA） com posite nanospheres bearing carboxylic functional group on the surface, were faciely prepared by one step emulsion polymerization in the presence of the magnetic fluid. Dynamic light scattering, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry and vibrating sample magnetometer measurements were used to characterize the size, morphology, structure, composition and magnetic property of the composite nanospheres, respectively. Results show that the obtained composite nanospheres were of an average diameter of about 122 nm and with carboxytic functional groups on their surfaces. Also, they were superparamagnetic and with a fairly high saturation magnetization at room temperature.