Self-assembly of colloidal particles in deformation landscapes of electrically driven layer undulations in cholesteric liquid crystals
Self-assembly of colloidal particles in deformation landscapes of electrically driven layer undulations in cholesteric liquid crystals
复制标题
胆甾型液晶电驱动层起伏变形景观中胶体颗粒的自组装
DOI：
10.1103/physreve.94.042709
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发表时间：
2016
影响因子：
2.4
通讯作者：
Smalyukh, Ivan I.
中科院分区：
文献类型：
--
作者：
Varney, Michael C.;Zhang, Qiaoxuan;Senyuk, Bohdan;Smalyukh, Ivan I.
我们研究了在垂直于胆甾层的电场作用下，胆甾相液晶中胶体粒子与起伏形变景观之间的弹性相互作用。起伏不稳定性的开始受胶体包裹体的存在的影响，反过来，层的起伏调节了颗粒位置的空间图案。我们发现，围绕胶体颗粒表面的胆固醇层的弯曲促使起伏晶格在低于无包裹体液晶的明确阈值的电场下局部成核，并且所产生的晶格的开始在尺寸和方向上都受到使用激光镊子定义的胶体初始排列的局部影响。球形颗粒倾向于在空间上定域在胆固醇层的强烈扭曲区域，而胶体纳米线则表现出沿波动晶格的不同矢量的多稳态取向偏移的额外偏好。超顺磁性胶体颗粒的磁旋转与局部扭曲的螺旋轴和起伏的胆固醇层以允许这些颗粒的受控三维平移的方式耦合。这些相互作用模式有助于深入了解液晶结构-胶体弹性相互作用的物理机制，并为可重构胶体复合材料的引导自组装指明了方向，在衍射光学和光子学中具有潜在的应用前景。
We study elastic interactions between colloidal particles and deformation landscapes of undulations in a cholesteric liquid crystal under an electric field applied normal to cholesteric layers. The onset of undulation instability is influenced by the presence of colloidal inclusions and, in turn, layers’ undulations mediate the spatial patterning of particle locations. We find that the bending of cholesteric layers around a colloidal particle surface prompts the local nucleation of an undulations lattice at electric fields below the well-defined threshold known for liquid crystals without inclusions, and that the onset of the resulting lattice is locally influenced, both dimensionally and orientationally, by the initial arrangements of colloids defined using laser tweezers. Spherical particles tend to spatially localize in the regions of strong distortions of the cholesteric layers, while colloidal nanowires exhibit an additional preference for multistable alignment offset along various vectors of the undulations lattice. Magnetic rotation of superparamagnetic colloidal particles couples with the locally distorted helical axis and undulating cholesteric layers in a manner that allows for a controlled three-dimensional translation of these particles. These interaction modes lend insight into the physics of liquid crystal structure-colloid elastic interactions, as well as point the way towards guided self-assembly of reconfigurable colloidal composites with potential applications in diffraction optics and photonics.