【作者】 冯雪娇；

【导师】 高歌； 徐蔚青；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2007， 硕士

【摘要】 本文使用绿色化学方法,选用天然高分子多聚糖田菁胶(SG)为还原剂和稳定剂,一步合成了一种具有环保特性的、稳定性好的银溶胶。该反应体系只有田菁胶、硝酸银和水三种物质,是一种简单的合成银纳米粒子的绿色合成法。本论文做了以下三方面工作: 1.以田菁胶为还原剂和稳定剂,在加热条件下合成了各向异性的银纳米粒子。通过紫外-可见吸收光谱(UV-Vis)、透射电子显微镜(TEM)对生成的银纳米粒子进行了表征,考察了不同反应温度、反应时间下溶胶的紫外变化,并研究了这种银溶胶的表面增强拉曼光谱(SERS)活性。此银溶胶放置两个月未发生明显的聚集,与使用柠檬酸钠法制得的溶胶相比,具有很好的稳定性。2.根据绿色化学法,室温条件下,使用田菁胶为还原剂和稳定剂合成银溶胶。通过紫外-可见吸收光谱研究了反应物浓度、反应时间对反应的影响;通过透射电子显微镜对银纳米粒子形貌进行表征;利用傅立叶变换红外光谱仪(FT-IR)对田菁胶和反应所得到的银溶胶的结构进行表征;对溶胶的拉曼光谱(Raman)进行检测,结果显示溶胶具有很好的Raman信号,室温下得到的溶胶表现出银纳米粒子对田菁胶的Raman信号增强作用。实验初步探讨了银溶胶的稳定性和成膜性,该溶胶自然干燥成膜后可以重新溶于水中,通过自然干燥方法得到银纳米粒子,使用银溶胶变得方便。3.使用激光诱导方法,以田菁胶和硝酸银为诱导对象,在光纤端面上沉积银纳米粒子。通过光学照片和扫描电子显微镜(SEM)对银纳米粒子的形貌进行表征,并将其作为一种光纤SERS传感器,对1, 4– 2 [2 - (4 -吡啶基)乙烯基]-苯(BVPP)分子进行了SERS检测。更多还原

【Abstract】 Along with the development of science and technology, nano-technology have developed rapidly in China, nano-materials have been widely applied to optical, electrical, and catalytic and other fields for its unique characterazation. Nano-silver which has very stable properties in the physical and chemical has been widely applied as coating materials and environmentally friendly materials and other fields. Currently,silver nano-materials have been extensively studied in the surface-enhanced filed.There are many ways to synthesize Silver nano-materials, such as chemical reduction, photochemical and electrochemical method. Every methods reflects its unique characteristic. however, Some of the approaches have caused certain harm to the environment, therefore,more and more researchers begin to use the method of green chemistry to synthesize nano-materials.Green Chemistry not using hazardous and toxic substances, not producing harmful toxic waste, not using backward production technology , not producing toxic products and making full use of green products, not releasing harmful substances. strive to prevent any pollution from the source. Comply with the requirements of sust-ainable economic development, Green chemistry is closely related to biology, physics, computer science, materials science, it will certainly spur the development of these subjects.Based on the above, this article summarized as the following three aspects :1. Anisotropy silver nanoparticles were synthesized using sesbania gum asreducer and stabilizer.The silver nanoparticles were synthesized using sesbania gum at hot temperature and characterized with UV-visible absorption spectroscopy, Scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Meanwhile, the SERS activity of colloid was also analyzed.The results show that the colloid is spherical,and some are polygon.it has better stablility compared with citrate-stablized silver colloid. Gold colloid was also reduced by sesbania gum. Its characterization was measured with UV-visible absorption spectroscopy and Fourier transform IR spectroscopy and transmission electron microscopy. The results show that sesbania gum is a very reductive, and we think that it will be applied to synthesize other metal nano-materials.2. Sesbania Gum-silver nanoparticles was synthesized at room temperature using green chemistry method.The effects of concentration, time on the reaction was measured by UV-visible absorption spectra , the morphology of the silver nanoparticles was characterized by transmission electron microscopy; The structure of Sesbania Gum and silver colloid was measured by Fourier transform infrared spectroscopy .We Preliminary studied the stability of colloidal silver and filming , the entire system was under room temperature, using sesbania gum as reductant,which is a natural, non-toxic polymer, water as a solvent, it provides a mild reaction conditions, one step,“green synthesis“method of silver nanoparticles.3 . The mixed solution of Sesbania Gum and silver nitrate was induced bylaser .Silver nanoparticles were deposited on the fiber end face by laser-induced method. The morphology of silver nanoparticles was measured by scanning electron microscopy(SEM), SERS of molecular BVPP was detected by optical fiber probe.更多还原