Lehmann rotation of cholesteric droplets subjected to a temperature gradient: Role of the concentration of chiral molecules
Lehmann rotation of cholesteric droplets subjected to a temperature gradient: Role of the concentration of chiral molecules
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DOI：
10.1140/epje/i2008-10431-3
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发表时间：
2009-04-01
影响因子：
1.8
通讯作者：
Oswald, P.
中科院分区：
文献类型：
--
作者：
Oswald, P.
本文系统地研究了温度梯度作用下手性分子浓度变化时，液滴的莱曼旋转。所选择的液晶是掺杂有少量手性分子R811的8CB和8OCB的低共熔混合物。液滴的角速度强烈地依赖于它们的大小和手性分子的浓度。用三种不同的方法估计了莱曼系数。我们的结果是一致的莱曼系数成正比的手性分子的浓度。我们还表明存在一个临界尺寸的液滴，低于它，他们改变纹理和停止旋转。
We present a systematic study of the Lehmann rotation of cholesteric droplets subjected to a temperature gradient when the concentration of chiral molecules is changed. The liquid crystal chosen is an eutectic mixture of 8CB and 8OCB doped with a small amount of the chiral molecule R811. The angular velocity of the droplets strongly depend on their size and on the concentration of chiral molecules. The Lehmann coefficient is estimated by using three different methods. Our results are consistent with a Lehmann coefficient proportional to the concentration of chiral molecules. We additionally show the existence of a critical size of the droplets below which they change texture and stop rotating.