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Updated: Sep 15, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Twist Grain Boundary Phases in Proper Ferroelectric Liquid Crystals Realm
Damian Pociecha1, Jadwiga Szydlowska1, Nataša Vaupotič2,3
1Department of Chemistry, University of Warsaw, Warsaw, 02-089, Poland.
None:
The twist-grain-boundary (TGB) phases, characterized by a periodic, helical arrangement of blocks made of polar smectic phases, SmAF and SmCF, have been discovered. They are observed for rod-like molecules with a strong longitudinal dipole moment, featuring an (S)-2-methylbutyl end group having only weak twisting power, and emerge below the antiferroelectric SmAAF phase, where the lamellar structure is already well established. It is suggested that the structure is governed by electrostatic interactions amplified by weak chiral forces, in striking contrast to the mechanism of TGB phase formation found in non-polar materials. The TGB phases exhibit selective light reflection in the visible range, while the value of electric polarization confirms an almost perfectly ordered dipole alignment.
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