[Paper] Systematic Investigation of Molecular Structure of Nematic-phase Liquid Crystals for Reduction of Dielectric Loss in Microwave Control Applications

Abstract A simple way of determining the helix screw sense of a cholesteric phase using the Grandjean-Cano method is described. The helix pitch as well as its sense is investigated for ten cholesteric phases, induced by mesogenic chiral compounds in the nematic isomere mixture of 4-methoxy-4′-n-butylazoxybenzene (Nematic Phase 4, Merck). For the chiral compounds with nematic-like molecular structure it is found that the screw sense alternates with the number of bonds between the chiral centre and the ring system.

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The inherent dynamics of isotropic- and nematic-phase liquid crystals

The Journal of Chemical Physics ◽

10.1063/1.4953618 ◽

2016 ◽

Vol 144 (23) ◽

pp. 234505 ◽

Cited By ~ 2

Author(s):

Layne Frechette ◽

Richard M. Stratt

Keyword(s):

Liquid Crystals ◽

Nematic Phase ◽

Phase Liquid

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Dynamic Capacitance Changes by Flow Effect of Nematic-phase Liquid Crystals with Compressive Force

IEICE Transactions on Electronics ◽

10.1587/transele.2020dip0002 ◽

2020 ◽

Author(s):

Yosei SHIBATA ◽

Nobuki FUKUNAGA ◽

Takahiro ISHINABE ◽

Hideo FUJIKAKE

Keyword(s):

Liquid Crystals ◽

Nematic Phase ◽

Compressive Force ◽

Flow Effect ◽

Phase Liquid ◽

Dynamic Capacitance

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Synthesis of Liquid Crystals with Substituents in Terminal Benzene Cores and their Mesomorphic Behaviour

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.58.144 ◽

2015 ◽

Vol 58 ◽

pp. 144-153 ◽

Cited By ~ 3

Author(s):

Vinay S. Sharma ◽

R.B. Patel

Keyword(s):

Molecular Structure ◽

Liquid Crystals ◽

Spectral Data ◽

Homologous Series ◽

Nematic Phase ◽

Side Chain ◽

The Novel ◽

Methyl Ethyl ◽

Texture Image ◽

Mesomorphic Properties

A new homologous series consisting of thirteen homologues central ester and chalcone linkage with Pentyloxy side chain at terminal benzene ring is synthesized and their mesomorphic properties are studied, with the exception of the methyl, ethyl and propyl homologues. However, the rest of homologues show mesomorphism enantiotropically manner with exhibition of nematic phase. The texture image of the nematic mesophases is observed by optical polarizing microscope equipped with heating stage (POM) is threaded or Schlieren type. An odd-even effect is observed in the nematic-isotropic curve with alternation in transition temperatures. The mesomorphic properties of the novel series are compared with other structurally similar homologous series. Analytical and spectral data confirm the molecular structure of the compounds.

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Diffusionless transformation of soft cubic superstructure from amorphous to simple cubic and body-centered cubic phases

Nature Communications ◽

10.1038/s41467-021-23631-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jie Liu ◽

Wenzhe Liu ◽

Bo Guan ◽

Bo Wang ◽

Lei Shi ◽

...

Keyword(s):

Liquid Crystals ◽

X Ray Diffraction ◽

Photonic Materials ◽

Simple Cubic ◽

Cubic Phases ◽

Transmission Electron ◽

Phase Liquid ◽

Blue Phase ◽

Blue Phases ◽

Temperature Window

AbstractIn a narrow temperature window in going from the isotropic to highly chiral orders, cholesteric liquid crystals exhibit so-called blue phases, consisting of different morphologies of long, space-filling double twisted cylinders. Those of cubic spatial symmetry have attracted considerable attention in recent years as templates for soft photonic materials. The latter often requires the creation of monodomains of predefined orientation and size, but their engineering is complicated by a lack of comprehensive understanding of how blue phases nucleate and transform into each other at a submicrometer length scale. In this work, we accomplish this by intercepting nucleation processes at intermediate stages with fast cross-linking of a stabilizing polymer matrix. We reveal using transmission electron microscopy, synchrotron small-angle X-ray diffraction, and angle-resolved microspectroscopy that the grid of double-twisted cylinders undergoes highly coordinated, diffusionless transformations. In light of our findings, the implementation of several applications is discussed, such as temperature-switchable QR codes, micro-area lasing, and fabrication of blue phase liquid crystals with large domain sizes.

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