scholarly journals Nematic phases and the breaking of double symmetries

2007 ◽  
Vol 322 (3) ◽  
pp. 709-735 ◽  
Author(s):  
C.J.M. Mathy ◽  
F.A. Bais
Keyword(s):  
Nematic Phases ◽  
Double Symmetries

Liquid Crystal Trimers Incorporating Saturated Isosteres of Benzene and Exhibiting Modulated Nematic Phases

2019 ◽  
Author(s):  
Adam Al-Janabi ◽  
Richard Mandle
Keyword(s):  
Liquid Crystal ◽  
Helical Structure ◽  
Molecular Shape ◽  
Saturated Hydrocarbons ◽  
Fluid System ◽  
Structural Requirement ◽  
Disubstituted Benzene ◽  
Bona Fide ◽  
Nematic Phases ◽  
Bend Angles

<p>The nematic twist-bend (N<sub>TB</sub>) liquid crystal phase possesses a local helical structure with a pitch length of a few nanometres and is the first example of spontaneous symmetry breaking in a fluid system. All known examples of the N­<sub>TB­</sub> phase occur in materials whose constituent mesogenic units are aromatic hydrocarbons. It is not clear if this is due to synthetic convenience or a <i>bona fide</i> structural requirement for a material to exhibit this phase of matter. In this work we demonstrate that materials consisting largely of saturated hydrocarbons could also give rise to this mesophase. Furthermore, replacement of 1,4-disubstituted benzene with <i>trans</i> 1,4-cyclohexane or even 1,4-cubane does not especially alter the transition temperatures of the resulting material nor does it appear to impact upon the heliconical tilt angle, suggesting the local structure of the phase is unperturbed. Calculating the probability distribution of bend angles reveals that the choice of isosteric group has little impact on the overall molecular shape, demonstrating the shape-driven nature of the N<sub>TB</sub> phase. </p>

Carbonyl- and thioether-linked cyanobiphenyl-based liquid crystal dimers exhibiting twist-bend nematic phases

Tetrahedron ◽  
2020 ◽  
pp. 131870
Author(s):  
Yuki Arakawa ◽  
Kenta Komatsu ◽  
Yuko Ishida ◽  
Kazunobu Igawa ◽  
Hideto Tsuji
Keyword(s):  
Liquid Crystal ◽  
Nematic Phases

scholarly journals Hexakis(terthiophenylthio)benzene as a Mew Class Liquid Crystalline Molecule

1999 ◽  
Vol 23 (10) ◽  
pp. 596-597
Author(s):  
Shinobu Inoue ◽  
Shoji Nishiguchi ◽  
Satoshi Murakami ◽  
Yoshio Aso ◽  
Tetsuo Otsubo ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Smectic A ◽  
Smectic C ◽  
Nematic Phases

A disk-like molecule, in which six α-linked terthiophenes are connected to a central benzene core via a thioether linkage, shows a sequence of calamitic liquid crystalline mesomorphism involving smectic C, smectic A and nematic phases.

scholarly journals Dielectric Spectroscopy Analysis of Liquid Crystals Recovered from End-of-Life Liquid Crystal Displays

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2873
Author(s):  
Ana Barrera ◽  
Corinne Binet ◽  
Frédéric Dubois ◽  
Pierre-Alexandre Hébert ◽  
Philippe Supiot ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
End Of Life ◽  
Room Temperature ◽  
Liquid Crystal Displays ◽  
Dielectric Anisotropy ◽  
Frequency Range ◽  
Spectroscopy Analysis ◽  
Diamond Nanoparticles ◽  
Nematic Phases ◽  
Universal Law

In the present work, the dielectric properties of recycled liquid crystals (LCs) (non-purified, purified, and doped with diamond nanoparticles at 0.05, 0.1, and 0.2 wt%) were investigated. The studied LC mixtures were obtained from industrial recycling of end-of-life LC displays presenting mainly nematic phases. Dielectric measurements were carried out at room temperature on a frequency range from 0.1 to 106 Hz using an impedance analyzer. The amplitude of the oscillating voltage was fixed at 1 V using cells with homogeneous and homeotropic alignments. Results show that the dielectric anisotropy of all purified samples presents positive values and decreases after the addition of diamond nanoparticles to the LC mixtures. DC conductivity values were obtained by applying the universal law of dielectric response proposed by Jonscher. In addition, conductivity of the doped LC mixtures is lower than that of the undoped and non-purified LC.

Hexagonal and nematic phases of chains. II. Phase transitions

1991 ◽  
Vol 43 (6) ◽  
pp. 2922-2931 ◽  
Author(s):  
Jonathan V. Selinger ◽  
Robijn F. Bruinsma
Keyword(s):  
Phase Transitions ◽  
Nematic Phases

Refractive index measurements in uniaxial and biaxial lyotropic nematic phases

2016 ◽  
Vol 213 ◽  
pp. 186-190 ◽  
Author(s):  
W.S. Braga ◽  
O.R. Santos ◽  
D.D. Luders ◽  
N.M. Kimura ◽  
A.R. Sampaio ◽  
...  
Keyword(s):  
Refractive Index ◽  
Nematic Phases

scholarly journals Uniaxial and Biaxial Spin Nematic Phases Induced by Quantum Fluctuations

2007 ◽  
Vol 98 (16) ◽  
Author(s):  
Jun Liang Song ◽  
Gordon W. Semenoff ◽  
Fei Zhou
Keyword(s):  
Quantum Fluctuations ◽  
Nematic Phases
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