Characterization of local molecular ordering and the layer structure of smectic liquid crystals by synchrotron micro-beam scattering

同步加速器微束散射表征近晶液晶的局域分子有序性和层结构

• 批准号: 18360013
• 负责人: IIDA Atsuo
• 金额: $ 10.37万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18360013/
• 关键词: synchrotron radiation; X-ray microbeam; liquid crystal; smectic liquid crystal; aspherical X-ray mirror; resonant X-ray scattering; layer structure; small angle X-ray scattering

The purpose of the present study is to clarify the relation between the local layer structure and the local molecular ordering or orientation in (anti-) ferroelectric liquid crystals by synchrotron X-ray micro-beam scattering.Experiments have been performed on the beam-line 4A at the Photon Factory, Institute of materials structure science, KEK, using synchrotron radiation from a bending magnet. The textures observed in the smectic liquid crystal cells are in various sizes from a few μm to a few tens of pm corresponding to the cell thickness. In order to investigate the detailed structure, X-ray optics having appropriate performance (spatial resolution, angular divergence and intensity) were developed. By developing the bendable aspherical mirror system, X-ray micro-beams from a few μm to 30〜40 μm are now available. The small beam is effective for the high resolution experiment while the larger beam is suitable for the rapid data acquisition with the moderate radiation damage.The molecular ordering in the layer and the layer structure itself were investigated with X-ray micro-beams. With a high resolution large area X-ray CCD detector, we have succeeded in the measurement of the time resolved halo pattern from the electroclinic liquid crystal under the triangular and rectangular electric field. We have also succeeded in the measurement of resonant X-ray scattering from the small region of the liquid crystal consisting of bent type molecules, for the first time. Since the intensity of the resonant X-ray scattering is weak, whereas the liquid crystal itself is damaged easily with strong high density X-rays, we have investigated the optimum conditions of the beam size and the X-ray photon density. Furthermore, with an adoption of the high spatial resolution X-ray CCD camera, we have obtained the layer spacing with high accuracy. From these observations, the intra- and inter-layer molecular interactions were discussed.

为了研究铁电液晶中的局域层结构与局域分子有序或取向之间的关系，采用同步辐射X射线微束散射技术，在KEK材料结构科学研究所光子工厂的4A光束线上进行了实验研究。在近晶液晶盒中观察到的织构具有从几μm到几十μ m的各种尺寸，对应于盒厚度。为了研究详细的结构，X射线光学具有适当的性能（空间分辨率，角发散度和强度）的开发。通过研制可弯曲非球面反射镜系统，可以获得从几μm到30 ~ 40 μm的X射线微束。小光束适用于高分辨率实验，大光束适用于中等辐照损伤的快速数据采集。用X射线微束研究了膜层中的分子有序性和膜层本身的结构。利用高分辨率大面积X射线CCD探测器，成功地测量了三角形和矩形电场作用下电斜液晶的时间分辨晕斑图。我们还首次成功地测量了由弯曲型分子组成的液晶小区域的共振X射线散射。由于共振X射线散射的强度很弱，而液晶本身很容易被强的高密度X射线破坏，我们已经研究了光束尺寸和X射线光子密度的最佳条件。此外，采用高空间分辨率的X射线CCD相机，我们得到了高精度的层间距。从这些观察，层内和层间的分子相互作用进行了讨论。

项目成果

Characterization of focal conics in chiral smectic C liquid crystals by X-ray microdiffraction

X 射线微衍射表征手性近晶 C 液晶中的焦锥曲线

• 发表时间: 2007
• 期刊: Liquid Crystals 34
• 作者: A. Iida and Y. Takanishi

In-situ X-ray diffraction studies of formation process mesostructured silica films with highly aligned porous structure by dip-coating

浸涂形成高度排列多孔结构介孔二氧化硅薄膜的原位 X 射线衍射研究

• 发表时间: 2006
• 作者: H. Itoh;et. al.
• 通讯作者: et. al.

Frustrated Smectic Layer Structures in Bent-Shaped Dimer Liquid Crystals Studied by X-Ray Microbeam Diffraction

X 射线微束衍射研究弯曲形二聚体液晶中的受抑近晶层结构

• 发表时间: 2006
• 期刊: Phys. Rev. E 74
• 作者: Y. Takanishi;M. Toshimitsu;M. Nakata;N. Takada;T. Izumi;K. Ishikawa;H. Takezoe;J. Watanabe;Y. Takahashi and A. Iida
• 通讯作者: Y. Takahashi and A. Iida

Interlayer molecular orientation in the B1 phase of a prototype bent-core molecule P-6-O-PIMB studied by X-ray micro beam diffraction

通过 X 射线微束衍射研究原型弯核分子 P-6-O-PIMB 的 B1 相中的层间分子取向

• 发表时间: 2006
• 期刊: J.Mater.Chem. 16
• 作者: Yoichi Takanishi;Hideo Takezoe;Junji Watanabe;Yumiko Takahashi;Atsuo Iida
• 通讯作者: Atsuo Iida

Intralayer molecular orientation in the B1 phase of a prototype bent-core molecule P-6-O-PIMB studied by X-ray microbeam diffraction

通过 X 射线微束衍射研究原型弯核分子 P-6-O-PIMB 的 B1 相中的层内分子取向

• 发表时间: 2006
• 期刊: J. Mater. Chem. 16
• 作者: Yoichi Takanishi;Hideo Takezoe;Junji Watanabe;Yumiko Takahashi and Atsuo Iida
• 通讯作者: Yumiko Takahashi and Atsuo Iida