Development of a New Technique of Analyzing the Liquid Crystal Interface Reorientation Dynamics using Reflection FT-IR Time-Resolved Spectroscopy

本研究发展了两种新的光谱技术，分别具有空间和时间分辨率，以分析液晶分子在基片表面的取向动力学：1.为了分析液晶分子在电场诱导的取向转变过程中的基本链段过程，我们开发了一种新的步进扫描FT-IR时间分辨光谱法（FT-IR TRS），时间为200 ns-2.为了提高液晶的空间分辨力，为了能够分析液晶表面的再取向动力学，我们还开发了一种新的时间分辨偏振调制椭圆偏振光谱系统（PMSE）。该系统具有100 nm的空间分辨率和20 μ s的时间分辨率，使我们能够定量地分析液晶在基片表面附近的表面锚定效应和指向矢重取向动力学。我们已经能够开辟一个新的液晶动态分析领域，可以深入到该领域的详细亚分子机制-诱导的重取向转变在双相和近晶液晶。本研究所获得的结果可望有助于液晶显示器的进一步发展。

In this study, we have developed two new spectroscopic techniques, both with spacial and temporal resolution, in order to analyze the liquid crystal reorientation dynamics at the substrate surfaces.1.First, in order to analyze the elementary segmental processes of liquid-crystalline molecules during their electric-field induced reorientational transition, we have developed a new step-scan FT-IR time-resolved spectroscopy (FT-IR TRS) with 200ns time-resolution.Applicability of this new techniques has been demonstrated for nematic liquid crystals and for ferrolelectric smectic liquid crystals.2.To improve the spacial resolution and make it possible to analyze the liquid-crystal's surface reorientation dynamics, we have also developed a new time-resolved, polarization-modulated spectroellipsometry system (PMSE). This system, with 100nm spacial resolution and 20mus time-resolution, has enabled us to quantitatively analyze the surface anchoring effect and the director reorientation dynamics of liquid crystals in the very vicinity of substrate surfaces.By developing these new spectroscopic techniques, we have been able to open up a new field of dynamic analysis of liquid crystals that can penetrate into the detailed submolecular mechanisms of the field-induced reorientational transition in both nematic and smectic liquid crystals. The results obtained in this study are expected to be able to contribute to the further development of liquid crystal display devices.