以FeCl3?6H2O和FeCl2?4H2O为原料,通过化学共沉淀方法制备Fe3O4磁性纳米粒子,用油酸和十一烯酸钠对纳米粒子进行双重改性,得到固含量为4%的稳定水基磁流体.在该磁流体存在下,以苯乙烯和甲基丙烯酸缩水甘油酯为单体进行无皂乳液聚合,制备出磁性种子微球;在种子磁性微球存在下,以对苯乙烯磺酸钠,稀土配合物等为功能单体,通过无皂种子乳液聚合法制备磁性荧光微球,该微球表现出优异的磁学性能以及荧光性能.用傅立叶红外光谱仪、透射电子显微镜、X射线衍射仪、振动样品磁强计、荧光分光光度计对磁性荧光微球结构形貌以及磁性荧光性能表征.测试结果表明,所制备的种子微球以及磁性荧光微球呈良好的单分散性,Z均粒径分别为147 nm和 228 nm,热重分析表明磁性荧光微球中Fe3O4的含量为4.7%,与之对应的饱和磁化强度为0.396 emu/g,在595 nm和619 nm处观测到Eu3+的特征发射光谱.
Superparamagnetic Fe3O4 nanoparticles were synthesized by chemical coprecipitation method with FeCl3?6H2O and FeCl2?4H2O as raw materials,followed by the modification of their surfaces with oleic acid and sodium undecylenate,and a stable water-based magnetic fluid with solid content of 4% was obtained.The seed microspheres were prepared through soap-free emulsion polymerization with the existence of magnetic fluid,using styrene (St) and glycidyl methacrylate (GMA) as the monomers.Then core-shell magnetic fluorescent microspheres were prepared through soap-free seeded emulsion polymerization in the presence of seeded microspheres,using styrene (St),sodium 4-vinyl benzenesulfonate (NaSS) and rare earth complexes Eu(AA)3Phen as functional monomer,the microspheres exhibit excellent magnetic properties as well as fluorescent properties.The structure,morphology,magnetic and fluorescent properties of the microspheres were characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM),photon correlation spectroscopy (PCS),Fourier transform infrared spectroscopy (FTIR),vibrating sample magnetometer (VSM) and fluorescence spectroscopy.It was indicated that seed microspheres and magnetic fluorescent microspheres showed good monodispersity,with the average particle diameter of 147 nm and 228 nm respectively,TGA analysis showed that the Fe3O4 content of magnetic fluorescent microspheres was 4.7%,corresponding to a saturation magnetization of 0.396 emu/g,and characteristic emission spectra of rare earth Eu3 + were observed at 595 nm and 619 nm.