Evaluation of dynamics of liquid crystalline structures by time-resolved X-ray diffraction

本研究的目的是：（1）利用共焦X射线源，通过大功率和小功率X射线衍射确定新型液晶相的结构;（2）利用图像增强器和CCD相机，通过时间分辨X射线衍射评估近晶液晶的层动力学。为了提高入射X射线强度和减小光束尺寸，引入了共焦镜。在第二年，我介绍了图像增强器和CCD相机，以测量时间分辨X射线衍射。同时，我测量了P-8- 0 PIMB和5CB的二元混合物的B4和Bx相的X射线衍射，并确定了结构的混合比依赖性，在过去的一年中，我测量了X-8- 0 PIMB和5CB的二元混合物的层结构的末端链依赖性。结果表明，随着末端链的增加，结构由单层向二维阻挫结构转变。以前，在末端链长的碳数为16的化合物中，该结构被认为是双层的，但发现即使在该化合物中也形成受抑层，关于称为SmBPiso的光学各向同性中间相，已经发现选择性反射带因激光照射而移动。为了研究在这个过程中的层响应，我测量了这个阶段的时间分辨x射线衍射。结果，发现层响应为几百毫秒，这比光学响应（几毫秒）长。

The purposes of this research are (1) the determination of the structures of novel liquid crystalline phases by powerful and small bema X-ray diffraction using the confocal X-ray source, and (2) the evaluation of the layer dynamics of smectic liquid crystals by time-resolved x-ray diffraction using the image intensifier and CCD camera.In the first year, I introduced confocal mirror in order to increase the incident X-ray intensity and to decrease the beam size. In the second year, I introduced the image intensifier and CCD camera in order to measure time resolved x-ray diffraction. At the same time, I measured the x-ray diffraction of the B4 and Bx phases of binary mixture of P-8-0PIMB and 5CB, and the determined the mixing ratio dependence of the structures for two years.In the last year, I measured the terminal chain dependence of the layer structure of bent-shaped dimers. It was found that the structure changes from a single layer to the 2D frustrated one with increasing the terminal chain. Previously, the structure was considered to be bilayer in the compound in which the carbon number of the terminal chain length is 16, but it was found to form frustrated layer even in this compound.With respect to the optically isotropic mesophase called SmBPiso, it has been already found that the selective reflection band was shifted by the laser irradiation. In order to study-the layer response at this process, I measured time-resolved x-ray diffraction of this phase. As a result, the layer response was found to be several hundreds of msec, which is longer than the optical response (several msec).