Tanaka Shu, Yoshida Hiroyuki, Kawata Yuto, Kuwahara Ryusuke, Nishi Ryuji, Ozaki Masanori
Division of Electrical, Electronic and Information Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
Sci Rep. 2015 Nov 4;5:16180. doi: 10.1038/srep16180.
Cholesteric blue phases are liquid crystalline phases in which the constituent rod-like molecules spontaneously form three-dimensional, helical structures. Despite theoretical predictions that they are composed of cylindrical substructures within which the liquid crystal molecules are doubly twisted, real space observation of the arrangement of such structures had not been performed. Through transmission electron microscopy of photopolymerized blue phases with controlled lattice plane orientations, we report real space observation and comparison of the lattice structures of blue phases I and II. The two systems show distinctly different contrasts, reflecting the theoretically predicted, body centred and simple cubic arrangement of the double-twist cylinders. Transmission electron microscopy also reveals different tendencies of the two blue phases to align on unidirectionally rubbed surfaces. We thus show that TEM observation of alignment-controlled, photopolymerized liquid crystals can be a powerful tool to investigate complex liquid crystalline order.
胆甾相蓝相是一种液晶相，其中组成的棒状分子会自发形成三维螺旋结构。尽管有理论预测它们由圆柱形子结构组成，在这些子结构中液晶分子呈双螺旋扭曲，但此前尚未对这种结构的排列进行实空间观测。通过对具有可控晶格平面取向的光聚合蓝相进行透射电子显微镜观察，我们报告了蓝相I和蓝相II晶格结构的实空间观测及比较。这两个体系呈现出明显不同的对比度，反映了理论预测的双螺旋圆柱体的体心立方和简单立方排列。透射电子显微镜还揭示了两种蓝相在单向摩擦表面上的不同取向趋势。因此，我们表明，对取向可控的光聚合液晶进行透射电子显微镜观察可以成为研究复杂液晶有序性的有力工具。
