Fe3O4/介孔SiO2/稀土上转换杂化纳米结构的构筑与性能研究

项目名称： Fe3O4/介孔SiO2/稀土上转换杂化纳米结构的构筑与性能研究

项目编号： No.50802095

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 张云霞

作者单位： 中国科学院合肥物质科学研究院

项目金额： 20万元

中文摘要： 本项目首先构造了四氧化三铁/介孔二氧化硅/稀土纳米棒多功能杂化纳米结构，研究这种杂化结构的磁学与荧光性能，分析四氧化三铁磁性纳米晶的大小、二氧化硅壳包覆层的厚度以及与稀土纳米棒的复合等因素对杂化材料的磁敏感特性与荧光性能的影响，通过调整杂化结构中各组分的相对尺寸与含量，达到控制杂化纳米结构综合性能的目的；其次，为了提高探测灵敏度，通过自组织技术，将金纳米颗粒自组织在Y2O3:Eu微球的表面，开展了贵金属与稀土纳米粒子的杂化结构及其荧光增强特性方面的研究；再次，设计和控制了合成具有超顺磁性的Fe3O4@meso-C介孔空心碳壳，它们具有远高于商用活性炭的吸附能力，而且介孔空心碳壳吸附染料后很容易用磁铁进行分离，以便回收循环利用；最后，利用简单的溶剂热方法一步合成了银/四氧化三铁核壳纳米复合粒子，通过控制核/壳的尺寸，其光吸收特性可以在可见-近红外光区内连续可调，该复合结构完美地结合了贵金属和磁性纳米颗粒的各自优势，所合成的复合纳米颗粒集良好的光学特性与超顺磁性于一体，为现代生物医学领域诊断与治疗提供了新的途径并奠定了一定的材料基础，具有重要的科学意义和应用价值。

中文关键词： 磁性；荧光；多功能；杂化；纳米结构

英文摘要： We firstly synthesized multifunctional Fe3O4/mesoSiO2/rare earth nanorods hybrid nanostructures and investigated their magnetic and fluorescence properties. It was considered that the size of Fe3O4 nanocrystals, the thickness of SiO2 shell and the deposition of rare earth nanorods have the influence on the magnetic and fluorescence properties. The composite performance of these hybrid nanostructures can be controlled by tuning the size and relative amount. Secondly, Au nanoparticles were deposited on the surface of Y2O3:Eu microspheres by self-assembly technique and plasmon enhanced fluorescence was investigated. Thirdly, Fe3O4@meso-C nanocapsules with superparamagnetism were synthesized. The as-obtained Fe3O4@meso-C nanocapsules exhibited higher adsorption capabilities of organic pollutants compared with commercial activated carbon. Moreover, the dye-loaded Fe3O4@meso-C nanocomposites can be easily separated from the mixture by applying a magnet, which makes the nanocomposite as a reusable absorbent for fast, convenient, and highly efficient removal of pollutants from the wastewater. Finally, multifunctional Ag@Fe3O4 core/shell nanostructures were fabricated through a simple one-step solvothermal process via in situ reduction of AgNO3 and Fe(NO3)3 using ethylene glycol as the reducing agent. The plasmonic properties of the composite microspheres are profoundly influenced by the high dielectric constant of outer Fe3O4 shell layer and could be conveniently modulated over a broad spectral range spanning from the visible to the near-infrared (NIR) regions (789 nm) by simply altering the thickness of Fe3O4 shell. Combining tunable optical properties, strong magnetic response, and superior stability, these multifunctional nanomaterials may open up many exciting opportunities in biomedical applications, such as integrated imaging, diagnosis, targeted delivery, therapeutics and great potential applications in catalysis, photovoltaics, plasmonics, and optics.

英文关键词： magnetic; photoluminescence; multifunctional; hybrid; nanostructure