Study on the monolayer arrangement and optical properties of single-dispersed metallic particles on solid surfaces

固体表面单分散金属粒子的单层排列及光学性质研究

基本信息

批准号：
15560570
负责人：
HATTA Aritada
金额：
$ 1.98万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

1.Infrared absorption spectral measurements have been performed at normal incidence of radiation on octadecanethiol (ODT) deposited from ethanol-water mixed solutions onto colloidal silver particles (ca. 30 nm in diameter) on Si(111) substrates. The spectra taken as a function of silver mass thickness and ODT concentration. indicate that the absorption bands of ODT are enhanced in intensity in comparison to the case in which no silver particles are present. It is also found that regardless of ODT concentration each absorption band reaches a maximum in intensity at a particular mass thickness of the particles, suggesting an intimate relationship between the absorption enhancement and the aggregation of the particles. This indeed was supported by FE-SEM morphological inspection of the particles.2.Aggregation of silver colloidal particles in the hydrosol through chemisorption of ODT molecules has been investigated on the basis of UV-visible transmission and infrared attenuated total refle … More ction (ATR) experiments. As-prepared silver sol showed a single absorption peak centered at 395 nm due to plasma resonance of the particles. Upon addition of ODT-dissolved ethanol to the sol, the plasma resonance peak showed a redshift accompanying a broadening, an indication of the aggregation of the particles in the solution by ODT adsorption. By use of infrared ATR spectroscopy, it was found that the particles in the solution aggregate on the base plane of a germanium ATR prism upon addition of ODT-dissolved ethanol to the solution. At moderate ODT concentrations, intense aggregation via ODT adsorption takes place on the prism surface, thus making it possible to observe ODT absorption bands.3.Raman scattering from the adsorbed species on the colloidal particles after dropping on Si substrates has been taken using a He-Ne laser (632.8 nm) in order to more clarify the influence of ionic species produced during preparation of the colloidal silver sol upon aggregation of the particles after dropping the particles on the silicon substrate. A Raman band due to nitrate ion was observed. This band almost disappeared by immersing the deposited silicon substrate into pure water far 1 hour. However ; the nitrate band was observed more strongly after immersion of the substrate into the water for 5 hours. This increase of Raman scattering intensity can be explained by assuming that the environmental nitrate ions were diluted or adsorbed nitrate ions were desorbed more or less by the water and thereby aggregation of the silver colloid particles proceeded, leading to an increase of the so-called SERS active sites. Actually, no Raman bands due to ODT could be observed when the deposited silicon substrate was subsequently immersed into ODT-dissolved ethanol This maybe explained by assuming that the SERS active sites were occupied by nitrate ions. Less

1.从乙醇 - 水混合溶液沉积到胶体银颗粒上（直径30 nm）的乙醇 - 水混合溶液（直径30 nm）上的八烷醇（ODT）上，已经在辐射的正常发生率（ODT）上进行了1.三红外抽象光谱测量。该光谱取决于银质量厚度和ODT浓度的函数。表明与不存在银颗粒的情况相比，ODT的抽象带的强度增强了。还发现，在特定的粒子质量厚度下，每个滥用带均达到最大强度，这表明抽象增强与颗粒的聚集之间存在亲密关系。确实，已经通过紫外可见的传播和insundrared减弱的总refle，更多的是，更多的实验。根据颗粒的血浆共振，预备的银溶胶显示出一个以395 nm为中心的单个遭受峰值。将ODT溶解的乙醇添加到溶胶中后，等离子体共振峰显示出红移进行宽扩展，这表明通过ODT添加吸附在溶液中颗粒聚集。通过使用红外ATR光谱法，发现溶液中的溶液中的颗粒在将ODT溶解的乙醇添加到溶液中后，在锗ATR棱镜的基本平面上聚集。 At moderate ODT concentrations, intense aggregation via ODT addition takes place on the prism surface, thus making it possible to observe ODT sufferer bands.3.Raman scattering from the adsorbed species on the colloidal particles after dropping on Si substrates has been taken using a He-Ne laser (632.8 nm) in order to more clariify the influence of ionic species produced during preparation of the colloidal silver sol upon aggregation of the将颗粒滴在硅底物上后的颗粒。观察到由于硝酸盐离子引起的拉曼带。通过将沉积的硅基板浸入纯水中1小时的纯水中几乎消失了。然而;浸入水中5小时后，更强烈地观察到硝酸盐条带。可以通过假设环境硝酸离子被稀释或吸附的硝酸盐离子或多或少地通过水解吸，从而通过水稀释环境硝酸离子，从而可以通过水来解释拉曼散射强度的这种增加，从而使银胶体颗粒的聚集得出，从而增加所谓的SERS活性位点的增加。实际上，当随后将沉积的硅底物浸入ODT脱落的乙醇中时，无法观察到由于ODT而引起的拉曼带，因此可以通过假设SERS活性位点被硝酸盐离子占据。