1. Twist grain boundary phases in proper ferroelectric liquid crystals realmDamian Pociecha, Jadwiga Szydłowska, Nataša Vaupotič, Katarzyna Kwiatkowska, Marijus Juodka, Julian Spiess, John M. D. Storey, Corrie T. Imrie, Rebecca Walker, Ewa Górecka, 2025, izvirni znanstveni članek Ključne besede: chirality, liquid crystals, proper ferroelectrics, twist-grain-boundary
Objavljeno v DKUM: 19.08.2025; Ogledov: 0; Prenosov: 7
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2. Multiple twisted chiral nematic structures in cylindrical confinementMilan Ambrožič, Apparao Gudimalla, Charles Rosenblatt, Samo Kralj, 2020, izvirni znanstveni članek Opis: In this article, we theoretically and numerically study the chirality and saddle-splay elastic constant (K24)
-enabled stability of multiple twist-like nematic liquid crystal (LC) structures in cylindrical confinement. We focus on the so-called radially z-twisted (RZT) and radially twisted (RT) configurations, which simultaneously exhibit twists in different spatial directions. We express the free energies of the structures in terms of dimensionless wave vectors, which characterise the structures and play the roles of order parameters. The impact of different confinement anchoring conditions is explored. A simple Landau-type analysis provides an insight into how different model parameters influence the stability of structures. We determine conditions for which the structures are stable in chiral and also nonchiral LCs. In particular, we find that the RZT structure could exhibit macroscopic chirality inversion upon varying the relevant parameters. This phenomenon could be exploited for the measurement of K24.
Ključne besede: liquid crystals, chirality, confinement, saddle-splay elasticity, double twist deformations
Objavljeno v DKUM: 14.01.2025; Ogledov: 0; Prenosov: 7
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3. Photonic bandgap in achiral liquid crystals - a twist on a twistDamian Pociecha, Nataša Vaupotič, Magdalena Majewska, Ewan Cruickshank, Rebecca Walker, John M. D. Storey, Corrie T. Imrie, Cheng Wang, Ewa Górecka, 2021, izvirni znanstveni članek Opis: Achiral mesogenic molecules are shown to be able to spontaneously assemble into liquid crystalline smectic phases having either simple or double-helical structures. At the transition between these phases, the double-helical structure unwinds. As a consequence, in some temperature range, the pitch of the helix becomes comparable to the wavelength of visible light and the selective reflection of light in the visible range is observed. The photonic bandgap phenomenon is reported for achiral liquid crystals.
Ključne besede: chirality, helical structures, liquid crystals, photonic bandgap, twist–bend phases
Objavljeno v DKUM: 10.10.2024; Ogledov: 0; Prenosov: 10
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