2024-01-08 マサチューセッツ工科大学(MIT)
◆この発見は、キラル構造が非キラルな材料から非キラルな手段で出現する可能性を示唆し、新しいキラル構造の生成方法を開く可能性があります。このような構造は、複雑な分子構造を組み立てるためのらせんの足場として機能し、また光センサーとして使用できる可能性があります。
＜関連情報＞
- https://news.mit.edu/2024/stripes-flowing-liquid-crystal-suggest-chiral-fluids-0108
- https://www.nature.com/articles/s41467-023-43978-6
アキラルネマチック液晶における流動誘起周期的キラル構造 Flow-induced periodic chiral structures in an achiral nematic liquid crystal
Qing Zhang,Weiqiang Wang,Shuang Zhou,Rui Zhang & Irmgard Bischofberger
Nature Communications Published:08 January 2024
DOI:https://doi.org/10.1038/s41467-023-43978-6
Abstract
Supramolecular chirality typically originates from either chiral molecular building blocks or external chiral stimuli. Generating chirality in achiral systems in the absence of a chiral input, however, is non-trivial and necessitates spontaneous mirror symmetry breaking. Achiral nematic lyotropic chromonic liquid crystals have been reported to break mirror symmetry under strong surface or geometric constraints. Here we describe a previously unrecognised mechanism for creating chiral structures by subjecting the material to a pressure-driven flow in a microfluidic cell. The chirality arises from a periodic double-twist configuration of the liquid crystal and manifests as a striking stripe pattern. We show that the mirror symmetry breaking is triggered at regions of flow-induced biaxial-splay configurations of the director field, which are unstable to small perturbations and evolve into lower energy structures. The simplicity of this unique pathway to mirror symmetry breaking can shed light on the requirements for forming macroscopic chiral structures.
