Two-dimensional microrheology of freely suspended liquid crystal films.
Two-dimensional microrheology of freely suspended liquid crystal films.
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自由悬浮液晶薄膜的二维微流变学。
DOI：
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发表时间：
2011
影响因子：
8.6
通讯作者：
N. Clark
中科院分区：
文献类型：
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作者：
A. Eremin;S. Baumgarten;K. Harth;R. Stannarius;Z. Nguyen;A. Goldfain;C. Park;J. E. Maclennan;M. A. Glaser;N. Clark
近晶液晶形成结构和厚度高度均匀的自由悬浮流体膜，使其成为二维流体动力学研究的理想系统。我们通过直接观察这些流体膜中包含的二氧化硅球和近晶岛的重力漂移来测量颗粒迁移率和剪切粘度。在厚膜中，我们观察到由横向限制效应主导的流体动力学状态，夹杂物的流动性主要由流体流与薄膜固定边界的耦合决定。在薄膜中，夹杂物的流动性主要由流体与周围空气的耦合控制，正如萨夫曼-德尔布吕克理论所预测的那样。
Smectic liquid crystals form freely-suspended, fluid films of highly uniform structure and thickness, making them ideal systems for studies of hydrodynamics in two dimensions. We have measured particle mobility and shear viscosity by direct observation of the gravitational drift of silica spheres and smectic islands included in these fluid membranes. In thick films, we observe a hydrodynamic regime dominated by lateral confinement effects, with the mobility of the inclusion determined predominantly by coupling of the fluid flow to the fixed boundaries of the film. In thin films, the mobility of inclusions is governed primarily by coupling of the fluid to the surrounding air, as predicted by Saffman-Delbrück theory.