X-Ray Structural Study of the Effect of Substrate Preparation on Liquid Crystal Alignment

槽状衬底对液晶的排列在结构分子水平上仍未得到很好的理解。这个问题在根本上和技术上都很重要。微结构器件的使用越来越多，因此有必要更好地了解LC-衬底界面区域的结构，衬底制备类型如何影响它，以及它如何影响LC膜的体积。我们提出研究在栅格衬底上沉积的近晶LC的结构有序演化与膜厚度和膜深度的关系。衬底由光刻光栅组成，其周期和深度可以以可控的方式改变。我们利用x射线掠角技术定量表征了LC的结构演变。本研究提供了LC膜在两个不同的竞争界面之间的行为的详细信息。它将有相当大的影响，改进LC薄膜的应用，包括不同的和对称的表面。

The alignment of liquid crystals by grooved substrates is still not well understood at the structural molecular level. This problem is important both fundamentally as well as technologically. The increased use of microarchitectural devices makes it imperative to obtain a better understanding of the structure of the LC-substrate interfacial region, how it is affected by the type of substrate preparation and how it affects the bulk of the LC film. We propose to study the evolution of structure ordering of smectic LC's deposited on grated substrates on grated substrates as a function of film depth and film thickness. The substrates consist of photolithographed gratings whose period and depth can be changed in a controlled manner. We use the X-ray glancing angle technique to characterize quantitatively the LC structure evolution. This study provide detailed information on the behavior of LC films between two disimilar, competing interfaces. It will have considerable impact on the improved implementation of LC films for applications, involving both disimilar as well as symmetrical surfaces.