液晶中鞍展开和Oseen-Frank自由能的解释

IF 4.8 3区材料科学 Q2 CHEMISTRY, PHYSICAL

Liquid Crystals Reviews Pub Date : 2018-07-03 DOI:10.1080/21680396.2019.1581103

Jonathan V Selinger

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引用次数: 72

摘要

摘要本文重新审视了液晶物理学中的一个经典问题：向列型液晶的弹性模式是什么？该分析使用了最近的数学结构，将指向矢梯度张量分解为四种不同类型的数学对象，分别表示展开、扭曲、弯曲和第四种变形模式。利用这种结构，Oseen-Frank自由能可以写成四种模式的平方和，鞍展开可以被视为体积而不是表面弹性。这种解释为思考液晶物理学中先前的几个结果提供了另一种方式，包括：（1）胆甾醇相和蓝相之间的自由能平衡，（2）混合排列向列相单元中的指向矢变形，（3）限制在环面或圆柱体中的非手性液晶的自发扭曲，以及（4）近晶层的曲率。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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Interpretation of saddle-splay and the Oseen-Frank free energy in liquid crystals

ABSTRACT This article re-examines a classic question in liquid-crystal physics: What are the elastic modes of a nematic liquid crystal? The analysis uses a recent mathematical construction, which breaks the director gradient tensor into four distinct types of mathematical objects, representing splay, twist, bend, and a fourth deformation mode. With this construction, the Oseen-Frank free energy can be written as the sum of squares of the four modes, and saddle-splay can be regarded as bulk rather than surface elasticity. This interpretation leads to an alternative way to think about several previous results in liquid-crystal physics, including: (1) free energy balance between cholesteric and blue phases, (2) director deformations in hybrid-aligned nematic cells, (3) spontaneous twist of achiral liquid crystals confined in a torus or cylinder, and (4) curvature of smectic layers.

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来源期刊

Liquid Crystals Reviews CHEMISTRY, PHYSICALCRYSTALLOGRAPHY&n-CRYSTALLOGRAPHY

CiteScore

7.60

自引率

5.90%

发文量

期刊介绍： Liquid Crystals Reviews publishes review articles on all aspects of liquid crystal fundamentals and applied science, including experimental and theoretical studies of physical and chemical properties, molecular design and synthesis and engineering of liquid crystal devices. The Journal fosters cross-disciplinary exchange of ideas, encouraging authors to present material at a level accessible to specialists from other fields of science and engineering. Liquid Crystals Reviews provides the scientific community, in both academia and industry, with a publication of standing, guaranteed by the Editors and by the International Editorial Board who are active scientists in the worldwide liquid crystal community.