柔性核心弯曲形状手性二聚体的扭曲-晶粒边界-扭曲-弯曲相的指示。

Indication of a twist-grain-boundary-twist-bend phase of flexible core bent-shape chiral dimers.

作者信息

Murachver Matthew T, Nemati Ahlam, Salamończyk Mirosław, Bullock Carson, Sabata Zachary, Rahmani Haumed, Vorobiova Tetiana, Izadnegahdar Alain, Salili Seyyed Muhammad, Norman Victoria, Zhu Chenhui, Hegmann Torsten, Sprunt Samuel N, Gleeson James T, Jakli Antal I

机构信息

Chemical Physics Interdisciplinary Program & Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.

出版信息

Soft Matter. 2019 Apr 17;15(16):3283-3290. doi: 10.1039/c8sm02338g.

DOI:10.1039/c8sm02338g

PMID:30931469

Abstract

The effect of the molecular chirality of chiral additives on the nanostructure of the twist-bend nematic (NTB) liquid crystal phase with ambidextrous chirality and nanoscale pitch due to spontaneous symmetry breaking is studied. It is found that the ambidextrous nanoscale pitch of the NTB phase increases by 50% due to 3% chiral additive, and the chiral transfer among the biphenyl groups disappears in the NTB* phase. Most significantly, a twist-grain boundary (TGB) type phase is found at c > 1.5 wt% chiral additive concentrations below the usual N* phase and above the non-CD active NTB* phase. In such a TGB type phase, the adjacent blocks of pseudo-layers of the nanoscale pitch rotate across the grain boundaries.

摘要

研究了具有双手性和由于自发对称性破缺导致的纳米级螺距的扭曲弯曲向列相（NTB）液晶相中手性添加剂的分子手性对其纳米结构的影响。发现由于3%的手性添加剂，NTB相的双手性纳米级螺距增加了50%，并且在NTB相中联苯基团之间的手性转移消失。最显著的是，在低于通常的N相且高于非CD活性的NTB*相的手性添加剂浓度c>1.5 wt%时，发现了一种扭曲晶粒边界（TGB）型相。在这种TGB型相中，纳米级螺距的伪层相邻块体跨晶粒边界旋转。