奈米銀具有非常特殊的光學性質，當電磁波通過金屬奈米粒子時，奈米粒子上的 電子會受交流電場的驅動而產生振盪，並在奈米粒子表面產生表面電漿子(surface plasmon)。當此電磁波波長接近此金屬奈米粒子的表面電漿共振波長 λSP 時，會因局部 表面電漿共振現象而有相當大的光吸收。此表面電漿子共振效應在三個方面有潛在應用 領域，生醫方面：生物感測元件、生物抗菌技術等；光電方面：高亮度 LED，染料敏化 太陽能電池等；奈米檢測方面：散射式掃描近場光學顯微鏡，表面電漿顯微鏡等。然而， 國內對於結合『粒子工程』與『表面電漿』用於製造『核殼奈米結構粒子』的相關研究， 相當缺乏。 本計畫『銀奈米顆粒披覆於氧化物奈米球之合成及其塗佈之運用』為一年期的計 畫。在執行面可以分為三種主要核殼奈米材料，且兩個階段來研發： 1. 合成出不同幾何形狀的核殼奈米粒子：(1)二氧化矽/銀核殼奈米粒子、(2)二氧化鈦/ 銀核殼奈米粒子及(3)二氧化錫/銀核殼奈米粒子。利用 Stöber 法及熔膠凝膠法製作二氧 化矽、二氧化鈦及二氧化錫核心奈米球。再用表面修飾法、種子成長法與低溫退火，合 成出不同外形的三種不同材質的核殼奈米粒子。並以材料、抗菌及奈米光學分析技術， 找出有潛力的樣品，作為第二階段的主要塗料。 2. 將第一階段先合成出有潛力的多種核殼奈米粒子，在本階段利用濕式薄膜塗佈機，塗 佈於PE、玻璃、氧化矽平板，而後分別做抗菌、奈米光學測試及太陽能光學及電學測試。 依所需之不同找出適當的奈米銀幾何因子及披覆方式，來提升奈米銀之應用，除了 作為學術研究之目的，更為國內相關產業作為技術提升、專利突破之引導。 The optical properties of silver nanoparticles have attracted much attentions due to the potential applications in biomaterials, biosensors, LED devices, dye- sensitized solar cells etc. Electrons on the surface of metal nanoparticles can be set into oscillation when electromagnetic waves pass through and surface plasmons are thus generated. Large light absorption will take place when the incoming wave length is comparable to that of the surface plasmon resonance. There are few literatures available on the fabrication of metal oxide-silver core-shell nanospheres, that directly and effectively combine the particle engineering and the surface plasma. This proposal entitled “Studies on the synthesis of metal oxide-Ag core-shell nanospheres and on the applications of the spin coatings” is an one-year project which consists of two major steps: Step 1, SiO2, TiO2 and SnO2 nanospheres(~330 nm) will be fabricated by Stöber sol-gel methods and followed by the oxide-metal core-shell formation to have combinations of TiO2- , SiO2- and SnO2-Ag products through surface decorated method, seed-mediated growth technique and annealing will finally be analyzed according to the aspects of material, interphase and biocompatibility. Step 2, Spin coating will be applied to produce several potential core-shell nanospheres on PE, glass and quartz substrates. Subsequent studies on structure, chemical composition, optical transparency and I-V curve are evaluated and compared in terms of the performance. It is interesting and worthwhile to find out the working parameters of the core-shell nanospheres formation as step 1, and the eventual quality and performance of the spin-coated core-shell nanospheres on various substrates as step 2. The outcome of this task would mean that the nanotechnology of metal oxide-Ag core-shell is not only beneficial to academic research but also to the high-tech industries in Taiwan.
