配体交换法制备水性含稀土磁性荧光微粒的研究及表征

Preparation and Characterization of the Water-dispersible Magnetic Fluorescent Particles Containing Rare Earth Prepared by Ligand Exchange Reaction

利用共沉淀法合成Fe3O4磁性纳米粒子,并使用油酸改性生成了粒径均一的油性纳米粒子.使用3-(甲基丙烯酰氧)丙基三甲氧基硅烷,聚乙二醇甲基丙烯酸酯以及荧光可聚合配合物Eu(AA)3Phen为原材料合成了含有稀土金属Eu的两亲性的聚合物为配体,以油性Fe3O4为核,采用配体交换反应制备水性的磁性荧光微粒.并通过核磁共振波谱仪、傅里叶红外光谱仪、透射电子显微镜、动态光散射粒径测试仪、X射线衍射仪、振动样品磁强计、荧光分光光度计、热重分析仪对该微粒进行形貌、结构、超顺磁性以及荧光性能的测试表征.测试结果表明,两亲性聚合物良好有效地包覆在了磁性纳米粒子表面,制得的含稀土磁性荧光微粒在水相中具有良好的分散性,粒径均一,其平均粒径仅为45 nm,室温下的饱和磁化强度为2.3 A·m2/kg,研究过程中测得微粒中的稀土Eu3+在594 nm和619 nm有明显的特征发射光谱.

After utilizing eoprecipitation method and subsequent modification with oleie acid,oil-based Fe304 magnetic nanoparticles with a narrow size distribution were obtained. And a kind of amphiphilic polymer containing rare earth was synthesized by using poly （ethylene glycol） methacrylate, methacryloxy propyl trimethoxyl silane and a complex Eu （AA）3Phen as monomers. The oil-based magnetic Fe304 nanoparticles were then used as cores, and modified with the amphiphilic polymer via ligand exchange reaction to prepare water-based magnetic fluorescent particles （ PMNPs）. The morphology, molecular structure, superparamagnetic and fluorescent properties of the particles were characterized by nuclear magnetic resonance spectrometer （NMR）, FTIR spectrometer （FEIR）, transmission electron microscope （TEM）, photon correlation spectroscopy （ PCS ）, X-ray diffractometer （ XRD ）, vibrating sample magnetometer （ VSM ）, fluorescence spectrometer and thermo gravimetric analyzer （TGA）. Results showed that the amphiphilic polymer was coated onto the surface of magnetic Fe3 04 nanoparticles effectively and evenly. The magnetic fluorescent particles had a good dispersibility in water phase and can keep a uniform particle size. The average diameter of the particles was just around 45 nm. The particles also had a saturation magnetization of 2.3 A·m2/kg at room temperature, and the rare earth Eu3＋ in these PMNPs had obvious characteristic emission spectra at 594 nm and 619 nm with a excitation spectra at 327 nm. Keywords