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The Solution of the Puzzle of Smectic‐Q: The Phase Structure and the Origin of Spontaneous Chirality
Author(s) -
Lu Huanjun,
Zeng Xiangbing,
Ungar Goran,
Dressel Christian,
Tschierske Carsten
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201712812
Subject(s) - gyroid , helicity , homochirality , chirality (physics) , substructure , phase (matter) , crystallography , planar , chemical physics , materials science , molecular physics , symmetry breaking , topology (electrical circuits) , chemistry , chiral symmetry breaking , physics , stereochemistry , quantum mechanics , polymer , computer science , enantiomer , mathematics , nambu–jona lasinio model , structural engineering , computer graphics (images) , engineering , copolymer , composite material , combinatorics
The so‐called smectic‐Q (SmQ) liquid crystal phase was discovered in 1983 in rod‐like molecules, but its structure remain unclear in spite of numerous attempts to solve it. Herein, we report what we believe to be the solution: A unique bicontinuous phase that is non‐cubic and is made up of orthogonal twisted columns with planar 4‐way junctions. While SmQ had only been observed in chiral compounds, we show that this chiral phase forms also in achiral materials through spontaneous symmetry breaking. The results strongly support the idea of a helical substructure of bicontinuous phases and long‐range homochirality being sustained by helicity‐matching at network junctions. The model also explains the triangular shape of double‐gyroid domains growing within a SmQ environment. SmQ‐forming materials hold potential for applications such as circularly polarized light emitters that require no alignment or asymmetric synthesis.