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

本研究的目的是：(1)利用共聚焦x射线源的强、小倍频x射线衍射确定新型液晶相的结构；(2)利用像增强器和CCD相机的时间分辨x射线衍射评价近晶液晶的层动力学。第一年，为了增加入射x射线的强度，减小光束的尺寸，我引入了共聚焦镜。第二年，我引入了图像增强器和CCD相机，用于测量时间分辨x射线衍射。同时，对P-8-0PIMB和5CB二元混合物的B4和Bx相进行了x射线衍射测量，测定了两种结构的混合比依赖性。在去年，我测量了弯曲型二聚体层结构的末端链依赖性。发现随着末端链的增加，结构由单层变为二维受挫结构。在此之前，在末端链长碳数为16的化合物中，该结构被认为是双层结构，但即使在该化合物中也发现它形成了受挫层。对于称为SmBPiso的光学各向同性中间相，已经发现激光照射导致选择性反射带移位。为了研究这一过程中的层响应，我测量了该相的时间分辨x射线衍射。结果发现，层响应为数百微秒，比光学响应（数微秒）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).