Research on Availability of Shear-induced Method for Making Bulk Colloidal-Photonic Crystals

本研究的目的是阐明一种新方法的特点，这种新方法可能是一种固化由胶体粒子组成的块状单晶光子晶体的东工艺。本文提出的方法是通过强剪切流将多晶胶体分散的起始材料重新排列成单晶形式。我们研究了剪切诱导过程是否有效，甚至对于厚如毫米大小的大块样品。对剪切后的样品进行了光谱分析，发现随着剪切速率的增加，样品的透光率急剧增加，达到饱和状态。研究了透射率与样品厚度的关系，表明厚样品的光学质量与薄样品一样好。这意味着剪切诱导法对厚（大块）样品也是有效的。然而，我们遇到了一个问题，固定化排列厚胶晶体的光诱导凝胶。入射光的衰减导致样品内部聚合不足，特别是当样品较厚时，这一问题无法通过简单的加强光照射来解决，从而导致凝胶样的光学质量恶化，这是今后的工作。

The purpose of this research is to clarify the characteristics of a new method that could be a East process to firm bulk, single-crystalline photonic crystals consisted of colloidal particles. The method proposed here is that the starting material of polycrystalline colloidal dispersion is realigned into a single-crystalline form by strong shear-flow.We investigated whether the shear-induced process was effective or not even for bulk samples as thick as millimeter size. Sheared samples were examined by optical spectrometry, and we found that transmittance of the samples was drastically increased and saturated with increasing the shear rate. Dependence of transmittance on the sample thickness was also investigated, and it was suggested that optical quality of the thick samples was as good as the thin sample. This means the shear-induced method is effective also Sir the thick (bulk) samples.However we encountered a problem for immobilizing the aligned thick colloidal crystals by means of photo-induced gelation. Attenuation of incident light causes insufficient polymerization inside, a sample especially when the sample is thick This problem could not be solved by simply strengthening light-irradiation, which caused deterioration in optical quality of gelled samples, and remained as future works.