scholarly journals Synthesis and Mesomorphic Properties of Novel Bent-shaped Naphthyl Diketones

2019 ◽  
Vol 92 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Anđela Buljan ◽  
Anamarija Knežević ◽  
Irena Dokli ◽  
Andreja Lesac
Keyword(s):  
Thermal Behaviour ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Molecular Packing ◽  
Broad Temperature Range ◽  
Structural Modifications ◽  
Temperature Range ◽  
Mesomorphic Properties

The synthesis and liquid-crystalline properties are reported for novel naphthyl-based diketones incorporating variant terminal chains and lateral fluoro- substitution. Newly prepared materials exhibit a broad temperature range of the nematic phase. The study demonstrates how subtle structural modifications can be exploited to alter the efficiency of molecular packing and consequently the thermal behaviour.

New liquid crystalline material with a broad temperature range ferroelectric phase

1994 ◽  
Vol 44 (7) ◽  
pp. 717-720 ◽  
Author(s):  
M. Kašpar ◽  
H. Sverenyák ◽  
V. Hamplová ◽  
S. A. Pakhomov ◽  
M. Glogarová
Keyword(s):  
Liquid Crystalline ◽  
Ferroelectric Phase ◽  
Crystalline Material ◽  
Broad Temperature Range ◽  
Temperature Range ◽  
Liquid Crystalline Material

Synthesis and Properties of Liquid Crystalline Polyurethanes from 4,4-bis (6-hydroxyhexoxy) Biphenyl and 3,3'-Dimethyl-4, 4’-Biphenylene Diisocyanate

2010 ◽  
Vol 428-429 ◽  
pp. 144-149
Author(s):  
Xiao Dong Chen ◽  
Nan Qiao Zhou ◽  
Hai Zhang
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Decomposition Temperature ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Temperature Range

A thermotropic liquid crystalline polyurethane (LCPU) was synthesized by the polyaddition reaction of 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI) with 4,4-bis(6-hydroxyhexoxy)biphenyl (BHHBP). The liquid crystalline behavior of the polymer was investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD). The LCPU exhibited a nematic phase with a threaded texture and had a wide mesophase temperature range. And thermogravimetric analysis (TGA) indicated the decomposition temperature of the LCPU was >300°C. The observation of POM showed that the LCPU was a thermotropic nematic liquid crystalline polymer at certain temperature range.

Dielectric properties of LC mixture with induced antiferroelectric phase

2008 ◽  
Vol 16 (3) ◽  
Author(s):  
M. Wojciechowski ◽  
G. Bąk ◽  
M. Tykarska
Keyword(s):  
Liquid Crystalline ◽  
Low Frequency ◽  
Broad Temperature Range ◽  
Relaxation Mode ◽  
Temperature Range ◽  
Antiferroelectric Phase ◽  
Mode Characteristic ◽  
Low Frequency Mode ◽  
Identification And Characterization

AbstractMixture of two liquid crystalline components exhibits the antiferroelectric phase in a broad temperature range at room temperatures, though the two components separately do not show an antiferroelectric phase in a temperature range applied. The dielectric spectroscopy technique combined with measurements of the selective light reflection was used for identification and characterization of the phases and subphases existing in the mixture. In the SmC*A phase, the low frequency mode characteristic of antiferroelectric phase has been detected. In the broad temperature range between SmC*A and SmA* phases, no relaxation mode has been detected. The soft mode registered near the phase transition to SmA* phase follows the Curie-Weiss law.

A passively mode-locked quantum-dot laser operating over a broad temperature range

2012 ◽  
Vol 101 (7) ◽  
pp. 071112 ◽  
Author(s):  
J. K. Mee ◽  
M. T. Crowley ◽  
N. Patel ◽  
D. Murrell ◽  
R. Raghunathan ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Broad Temperature Range ◽  
Temperature Range ◽  
Quantum Dot Laser

Nanowires self-assemble into β-MnO2 nanospheres to form crosslinking 3D hierarchical porous networks: with template-free fabrication and good supercapacitive performance over a broad temperature range

2021 ◽  
Vol 5 (19) ◽  
pp. 4944-4954
Author(s):  
Li-Li Yu ◽  
Wei-Ling Xu ◽  
Jian-Guo Zhang ◽  
Shuang Li ◽  
Rong-Bing Li ◽  
...  
Keyword(s):  
Broad Temperature Range ◽  
Supercapacitive Performance ◽  
Temperature Range ◽  
Porous Networks ◽  
Self Assembling ◽  
Hierarchical Porous ◽  
Template Free

Template-free fabrication of nanowires self-assembling into nanospheres and crosslinking into 3D hierarchical porous β-MnO2 networks with good supercapacitive performance over a broad temperature range.

Photophysical, electrochemical, and mesomorphic properties of a liquid-crystalline [60]fullerene–peralkylated ferrocene dyad

2008 ◽  
Vol 18 (13) ◽  
pp. 1504 ◽  
Author(s):  
Stéphane Campidelli ◽  
Marjorie Séverac ◽  
David Scanu ◽  
Robert Deschenaux ◽  
Ester Vázquez ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Mesomorphic Properties

Liquid Crystalline Properties of 4,4and#39;-methylenebis(N-(4-Alkanoxybenzylidene)aniline): Synthesis, Characterization, and Theoretical study

2019 ◽  
Vol 41 (6) ◽  
pp. 1107-1107
Author(s):  
Mohammed Taha Yaseen and Abdullah Hussein Kshash Mohammed Taha Yaseen and Abdullah Hussein Kshash
Keyword(s):  
Liquid Crystalline ◽  
Theoretical Study ◽  
Basis Set ◽  
Spectroscopic Techniques ◽  
Benzene Nucleus ◽  
Crystal Properties ◽  
Ft Ir ◽  
Alkoxy Groups ◽  
Gaussian Program ◽  
Mesomorphic Properties

The paper presents six homologues series of Schiff bases ether compounds distinguished by the length of terminal alkoxy groups which substituted on a side benzene nucleus. The above structures were demonstrated through the use of spectroscopic techniques, like FT- IR and 1H-NMR. Polarized hot stage optical microscopy was used to study both mesomorphic properties and phase transitions. The results showed that out of the six compounds only three (B2, B3 and B4) were pure (marble) nematic mesophase, while no liquid crystal properties for (B5, B6 and B7) compounds. The theoretical study for the electronic structures was intended to study the effects of alkyl chain length on the electronic structure by using Gaussian program, DFT and 6-31G as basis set. The theoretical results indicate that there is no effect to the terminal substituted alkoxy groups on the HOMO energies but there is an effect on LUMO energies through decreasing energy for the prepared compounds.

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