【作者】 郭翔；

【导师】 赵晓红；

【作者基本信息】 北京邮电大学 ， 光学， 2011， 硕士

【摘要】 自上世纪八十年代以来,纳米材料和纳米科技一直是最富有活力、内涵最为丰富、成果最为丰硕的科研领域之一。以银为代表的贵金属纳米材料具有特殊的光学性质,即表面等离子激元共振现象,广泛的应用于物理、生物、信息、光电等各个领域,并成为国际上研究的热点之一。银纳米材料的性能受形貌影响较大,因此,银纳米材料合成的可控性十分重要。基于以上背景,本课题实践并总结了纳米银材料的制备及表征过程中用到的实验思路及方法。包括以AgN03为银源、PVPK30为表面活性剂,乙二醇为溶剂和还原剂,高温条件下合成了不同形貌的银纳米颗粒、具有五重孪晶结构的银纳米线,以及在银纳米线的可控制备的基础上,使用溶胶-凝胶法合成了Ag@SiO2,和使用两种不同的方法——直接还原法和表面修饰后包覆法,制备了具有三层结构的Ag@SiO2@Ag纳米线。此外,讨论了不同银纳米结构的自组装方法,并进行了实验设计及探索。研究了银纳米线、纳米颗粒的形貌及光学性质。通过SEM、TEM、SEAD等手段详细的研究了银纳米结构的形貌特点,分析不同银纳米结构的紫外-可见吸收光谱、拉曼光谱,总结了反应参数,如浓度、滴加方式、温度以及其他因素对反应结果的不同影响,分析了纳米结构的吸收峰与其形貌变化的关系。此外还通过FDTD等仿真手段,研究了单根纳米线的光波导特性。分析了Ag@SiO2纳米线的SEM、TEM、SEAD等表征结果,详细的研究了其形貌特点,讨论了该结构的生长过程。并通过Ag@Si02纳米线的紫外-可见吸收光谱分析了其形貌特点对光学性质的影响。最后比较了两种方法下制备的Ag@SiO2@Ag三层结构的不同特点,并结合TEM等表征结果进行了详细讨论。更多还原

【Abstract】 Silver nanomaterial, one of the most active research fields in the metal nanometer materials, has a wide range of applications because of its unique heat, light, electricity and magnetism, catalysis and sensitive features.This dissertation is about synthesis and optical properties of Ag nanostructures with various morphologies. It discussed the methods and experiment details:First, the well-known ethylene glycol reduction method with polyvinylpyrrolidone (PVP) as surfactant was used to prepare Ag nanostructures with various morphologies. Second, the shape-controlled synthesis of Ag@SiO2 using stober method is described. And then, we develop two different methods for synthesizing Ag@SiO2@Ag. As an extension of our work, we discuss the designing and exploring experiment of self-assemble of nanostructures.The structure and optical properties of the as-prepared Ag nanostructures were investigated in detail; and the waveguiding properties of a single Ag nanowire were studied experimentally and theoretically. The results indicate that Ag nanowires are an effective waveguiding cavity, and the light can propagate through the nanowire from one end to another end with the assistance of surface plasmon resonance.We also investigate the structure and growth process of Ag@SiO2 by using the scanning electron microscope(SEM) and Transmission electron microscope (TEM). At the same time, we study the optical properties of this kind of structure by the analysis of its UV-vis absorption spectra.At last, we compare the result of the Ag@SiO2@Ag nanocables synthesizing by two different method, and discuss some details about it by using TEM.更多还原