【作者】 宋薇；

【导师】 赵冰；

【作者基本信息】 吉林大学 ， 物理化学， 2007， 博士

【摘要】 本文研究了几种微纳米结构材料的SERS及超疏水性质。利用一种简单化学置换的方法制备具有SERS活性的纳米银树枝,并研究了其增强机理,发现这种方法相对简单,不需要复杂的仪器与特别的反应物,而且可以广泛的推广至其他需要痕量检测的物质上。在二维排列的聚合物图案化金基底表面构筑了微纳米结构的银纳米粒子图案,并且通过拉曼成像的方法检测了这种的可以反映不同SERS活性的分等级的SERS微纳米结构基底。采用湿化学方法制备了银微球,发现银微球在激光的照射下,随着激光的照射时间的加长,在共聚焦显微镜下观察会逐渐变亮,由此研究了银微球表面的拉曼光谱的变化与银微球的发光与分子光谱发生变化的原因。在半导体表面包覆了银纳米粒子,得到了较好的表面SERS活性,并研究了其增强机理。由于半导体材料的广泛应用,对于其表面SERS的研究具有非常重要的价值。由于不同的微纳米结构材料的超疏水性质也不同,在研究SERS基底微纳米结构材料的同时,又发现了由于反应物浓度的不同能形成超亲水的银微球和高疏水的银花。最后,采用无电沉积法按金属活动顺序表的方式将一种金属浸入排在它后面的不同浓度的金属盐溶液中,得到了不同微纳米结构的超疏水基底,发现这些基底的微纳米结构的不同并不影响其接触角的大小,其接触角均在150°左右,进而研究了这些微纳米结构基底的形成机理及其表面的化学成分与结构。更多还原

【Abstract】 Micro-nanostructured materials are very important to the renovation and advancement of modern nanotechnology, which have been widely in the field of information, communication, automobile, medicine, biotechnology, analysis, diagnosis, chemistry, manufacture and environment protection. Surface enhanced Raman scattering (SERS) and wettability properties of materials are related with their micro-nanostructures, so the research of SERS and wettability on micro-nanostructured materials will have attracted more and more attention in the future. In this thesis, we study the SERS and wettability on several micro-nanostructured materials, including metal and semiconductor/metal composites:(1) A simple method of the reduction of AgNO3 by copper foil in aqueous medium was used to prepare silver dendrites, which can be used as a novel good reproducible SERS active substrate. The SERS spectra of 4-pyridinethiol on this novel substrate reflected the different SERS activities on the minuteness and strong Ag dendrites. The electromagnetic coupling enhancement and chemical enhancement mechanisms are used to explain the SERS effect. We are sure that it is a powerful analytical tool of determining chemical information for compounds.(2) The study of SERS for semiconductor nanoparticles are very important to extend the application of SERS and explore the deeply information of semiconductors. However, the SERS for semiconductors is very weak. In this section, SERS of 4-mercaptopyridine (4-Mpy) adsorbed on the surface of TiO2 nanofibers coated with Ag nanoparticles and ZnO/Ag composite microspheres were obtained. The SERS enhancement mechanisms have also been studied.(3) We prepared ordered two-dimensional arrays of patterns with silver nanoparticles immobilizing on the patterned self-assembled monolayers (SAM) of alkanethiolates on gold, which can be used as a hierarchical SERS substrate. SERS spectra and surface enhanced Raman mapping of 4-pyridinethiol SAM on this novel SERS active substrate were also investigated. The different SERS activities were observed on the surface of hierarchical micro-nanostructure. The enhancement factor was well studied and the electromagnetic enhancement mechanism was used to explain the SERS effect.(4) We report a simple wet-chemical method to prepare silver microflowers and large spherical particles. The controlling of the silver microstructures can be achieved only by adjusting the concentration of the reactants. It is found that the large spherical silver particles exhibit superhydrophilic properties, microflower-like silver particles exhibit highly hydrophobic properties. The Raman spectrum of large spherical silver particles was studied. (5) Here we report a remarkably straightforward method for preparing large scale superhydrophobic substrate which yields robust double roughness metal surface coatings and which is carried out under ambient conditions using readily available starting materials and laboratory equipment. The method uses electroless galvanic deposition to coat a metal substrate with a textured layer of a second metal.更多还原