無電電鍍法製備金屬反蛋白石結構與性質分析

Abstract

利用不同折射率的介電材料相互堆積成具有2D或3D結構之週期性奈米材料，其結構具有獨特的光子能隙性質，可將光加以限制，我們稱之為光子晶體。其應用相當廣泛，例如，可調式光學濾波器、光子晶體光纖、發光二極體等等。也可用於分析化學的應用上，例如，作為感測器，可以精確的感測金屬離子、葡萄糖、氣體等等，光子晶體的研究實為ㄧ門相當重要的科學。 光子晶體的製備方法很多，其中蛋白石結構(opals)與反式蛋白石結構(inverse opals)為實驗室中最常研究的對象。本文著重於鎳金屬反蛋白石結構的製備。根據文獻，製備金屬反蛋白石結構的方式多為電化學還原法或燒結法，然而，與燒結法和無電電鍍法比較，電化學還原法需要相對繁複的裝置；而燒結法則會出現破裂不完整的結構。本研究利用化學還原的原理，提供一新穎的方式來填充奈米鎳粒子。實驗步驟敘述如下，首先，將玻璃基板敏化活化，使鈀粒子覆蓋於玻璃基板表面做為活性點，再利用蒸發的方式將聚苯乙烯微球整齊排列於玻璃基板上，形成蛋白石結構，聚苯乙烯微球大小約550nm左右。把上述基板浸入還原液中，在適當溫度下，鎳金屬經由鈀金屬催化即於鈀表面產生還原，由結構底層持續向上堆積，最後使用THF除去聚苯乙烯微球後，即可得到鎳金屬反蛋白石結構。藉由不同反應時間，即可得到不同厚度的鎳金屬反蛋白石結構。此種方法可以製備大面積、結構完整的金屬反蛋白石結構，亦不需要複雜裝置，實在為一方便的製程。 最後，簡單量測已製得的鎳金屬反蛋白石結構之相關性質。利用紫外光(uv)量測金屬反蛋白石結構的光子能隙；掃描式電子顯微鏡(SEM)觀察鎳金屬堆積方式與型態；三用電錶與四點探針測量其導電性；X光(x-ray)確定鎳金屬的晶格結構等等。

Construct dielectric materials with different refractive indexes to stack and to form two - dimensional or three - dimensional of periodic nanostructures. Such unique structures have characteristic photonic band gaps, and can control and manipulate the flow of light. We call the structures be photonic crystal. Consequently, photonic crystals are of great interest in applied research and lead to broad applications, like tunable optical filters, photonic crystal fiber, light emitting diode, sensor, etc. The research of photonic crystal is really an important science.

One of the most researched structures in the laboratories is opals and inverse opals. The purpose of this article is to emphasize the synthesis in nickel inverse opals. According to references up to the present, electronic deposition and sintering are the methods used principally. However, the method of electronic deposition needs complicated equipment and takes longer time. The method of sintering would destroy the structures. We found a new method to fill nickel nanoparticles into interspace between polystyrene spheres. Experimental steps of fabricating the macroporous structure are described as follow: At first, make the glass template sensitized and activated, and palladium particles would cover the glass template to form catalytic sites. By evaporation, polystyrene spheres would align on the glass template to form three-dimensionally ordered opals. The diameter of polystyrene spheres is 550 nm. Put this template with polystyrene into the plating solution. At adequate temperature, nickel reduces from the surface of palladium and grows up to the top of colloidal crystal. Finally, use THF to take off polystyrene spheres, and we could get the structure of inverse opals. In different period of time, we could get nickel inverse opals with different thickness. By this method, we can synthesis metal inverse opals having large and unbroken areas without any expensive equipment. It’s really a convenient technology. SEM is carried out to observe the structure of Ni inverse opals. X-ray is used to confirm the lattice ,and ultraviolet ray is used to measure the band gap. Measure electronic conductivity with digital panel meter and 4 Point Probe .