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.

本研究的目的是通过同步加速器 X 射线微束散射阐明（反）铁电液晶中局域层结构与局域分子有序或取向之间的关系。在 KEK 材料结构科学研究所光子工厂的光束线 4A 上，使用来自弯曲磁体的同步加速器辐射进行了实验。在近晶液晶盒中观察到的纹理具有不同的尺寸，从几微米到几十微米，与盒的厚度相对应。为了研究详细结构，开发了具有适当性能（空间分辨率、角发散和强度）的 X 射线光学器件。通过开发可弯曲非球面镜系统，现在可以实现从几μm到30〜40μm的X射线微束。小光束适用于高分辨率实验，而较大光束适用于中等辐射损伤的快速数据采集。用X射线微束研究了层中的分子有序性和层结构本身。利用高分辨率大面积X射线CCD探测器，我们成功地测量了三角形和矩形电场下电斜液晶的时间分辨光晕图案。我们还首次成功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射线散射强度较弱，而强高密度X射线容易损坏液晶本身，因此我们研究了光束尺寸和X射线光子密度的最佳条件。此外，通过采用高空间分辨率的X射线CCD相机，我们获得了高精度的层间距。根据这些观察，讨论了层内和层间分子相互作用。

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