Graduate School of Nanoscience and Technology and KINC and ‡Department of Chemistry, KAIST , Daejeon 34141, Korea.
Langmuir. 2018 Feb 20;34(7):2551-2556. doi: 10.1021/acs.langmuir.7b04216. Epub 2018 Feb 6.
One of the alluring aspects of liquid crystals (LCs) is their readily controllable self-assembly behavior, leading to comprehension of complex topological structures and practical patterning applications. Here, we report on manipulating various kinds of topological defects by adopting an imprinted polymer-based soft microchannel that simultaneously imposes adjustable surface anchoring, confinement, and uniaxial alignment. Distinctive molecular orientation could be achieved by varying the surface anchoring conditions at the sidewall polymer and the rubbing directions on the bottom layer. On this pioneering platform, a common LC material, 8CB (4'-n-octyl-4-cyano-biphenyl), was placed where various topological defect domains were generated in a periodic arrangement. The experimental results showed that our platform can change the packing behavior and even the shape of topological defects by varying the rubbing condition. We believe that this facile tool to modulate surface boundary conditions combined with topographic confinement can open a way to use LC materials in potential optical and patterning applications.
液晶（LCs）的一个诱人之处在于其易于控制的自组装行为，这导致了对复杂拓扑结构的理解和实际的图案化应用。在这里，我们报告了通过采用基于压印聚合物的软微通道来操纵各种拓扑缺陷，该微通道同时施加了可调的表面锚定、限制和单轴取向。通过改变侧壁聚合物的表面锚定条件和底层的摩擦方向，可以实现不同的分子取向。在这个开创性的平台上，将一种常见的 LC 材料 8CB（4'-正辛基-4-氰基联苯）放置在其中，在那里可以以周期性排列生成各种拓扑缺陷域。实验结果表明，我们的平台可以通过改变摩擦条件来改变 LC 的堆积行为甚至拓扑缺陷的形状。我们相信，这种调节表面边界条件的简单工具与形貌限制相结合，可以为 LC 材料在潜在的光学和图案化应用中开辟道路。
