Liquid Crystalline Samples: Static and Dynamic Measurements of Director Alignment
Liquid Crystalline Samples: Static and Dynamic Measurements of Director Alignment
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液晶样品：指向矢排列的静态和动态测量
DOI：
10.1002/9780470034590.emrstm1321
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
G. Luckhurst
中科院分区：
文献类型：
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作者：
A. Sugimura;G. Luckhurst
在磁场和/或电场作用下，液晶的取向已经有了许多研究。这些重要的流体动力学过程的基本特征已经被描述为系统在平衡和非平衡状态下的特征。为了补充实验，已经开发了基于连续介质理论的理论模型，成功地描述了静态和动态现象。这种宏观行为已经用氘核磁共振（DNMR）光谱学研究，其中除了光谱仪的磁场之外，电场还用于旋转指向矢并产生非平衡态。这种强大的技术已被证明在液晶的研究中特别重要。由于在液晶相中观察到的氘核的四极分裂是由指向矢和磁场之间的角度决定的，因此时间分辨的DNMR光谱已经被用来研究在施加或去除电场之后的薄磁致伸缩膜中的动态指向矢对准过程。在这篇文章中，我们描述了说明性的关键研究，场诱导的指向矢取向低摩尔质量向列相使用DNMR与电场和磁场对齐的方向。
There have been many investigations on the alignment of nematic liquid crystals by either a magnetic and/or an electric field. The basic features of these important hydrodynamic processes have been characterized for systems in their equilibrium and non‐equilibrium states. To complement the experiments, theoretical models based on continuum theory have been developed, which successfully describe the static and dynamic phenomena. Such macroscopic behavior has been investigated with deuterium nuclear magnetic resonance (DNMR) spectroscopy, in which the electric field, in addition to the magnetic field of the spectrometer, is used to rotate the director and produce a non‐equilibrium state. This powerful technique has proved to be especially important in the investigation of liquid crystals. Since the quadrupolar splitting for deuterons observed in the liquid crystal phase is determined by the angle between the director and the magnetic field, time‐resolved DNMR spectroscopy has been employed to investigate the dynamic director alignment process in a thin nematic film following the application or removal of an electric field. In this article, we describe illustrative key studies of field‐induced director orientations for low molar mass nematics using DNMR with an electric and a magnetic field to align the director.