A Liquid-crystalline(Nematic) Phase with a Particularly Low Solidification Point

1969 ◽  
Vol 8 (11) ◽  
pp. 884-885 ◽  
Author(s):  
H. Kelker ◽  
B. Scheurle
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Solidification Point

Hydrogen bonding liquid crystalline benzoic acids with alkylthio groups: phase transition behavior and insights into the cybotactic nematic phase

2017 ◽  
Vol 41 (14) ◽  
pp. 6514-6522 ◽  
Author(s):  
Yuki Arakawa ◽  
Yukito Sasaki ◽  
Kazunobu Igawa ◽  
Hideto Tsuji
Keyword(s):  
Phase Transition ◽  
Hydrogen Bonding ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Benzoic Acids ◽  
Phase Transition Behavior ◽  
Transition Behavior

A novel class of hydrogen bonding liquid crystalline benzoic acids with alkylthio groups was established and their phase transition behavior was investigated in detail.

scholarly journals Order Parameters, Orientational Distribution Functions and Heliconical Tilt Angles of Oligomeric Liquid Crystals

2019 ◽  
Author(s):  
Richard Mandle ◽  
John W. Goodby
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Tilt Angle ◽  
Order Parameter ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Thermal Evolution ◽  
Order Parameters ◽  
Distribution Functions ◽  
Orientational Distribution

We compare the order parameters, orientational distribution functions (ODF) and heliconical tilt angles of the TB phase exhibited by a liquid-crystalline dimer (CB7CB) to a tetramer (O47) and hexamer (O67) by SAXS/WAXS. Following the N-TB phase transition we find that all order parameters decrease, and while 〈P2 〉 remains positive 〈P4 〉 becomes negative. For all three materials the order parameter 〈P6 〉 is near zero in both phases. The ODF is sugarloaf-like in the nematic phase and volcano-like in the TB phase, allowing us to estimate the heliconical tilt angle of each material and its thermal evolution. The heliconical tilt angle appears to be largely independent of the material studied despite the differing number of mesogenic units.

Helical twisting power and compatibility in twisted nematic phase of new chiral liquid crystalline dopants with various liquid crystalline matrices

2019 ◽  
Vol 46 (12) ◽  
pp. 1769-1779 ◽  
Author(s):  
Łukasz Duda ◽  
Maciej Czajkowski ◽  
Bartłomiej Potaniec ◽  
Petra Vaňkátová
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Twisted Nematic ◽  
Helical Twisting Power

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.

PBLG as a versatile liquid crystalline medium for anisotropic NMR data acquisition

2019 ◽  
Vol 55 (30) ◽  
pp. 4327-4330 ◽  
Author(s):  
Ikenna E. Ndukwe ◽  
Xiao Wang ◽  
István Pelczer ◽  
Mikhail Reibarkh ◽  
R. Thomas Williamson ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Solvent System ◽  
High Quality ◽  
Nmr Data ◽  
Chiral Nematic ◽  
Liquid Crystalline Medium ◽  
Crystalline Medium

The chiral nematic phase of poly-γ-benzyl-l-glutamate (PBLG) formed in a chloroform–DMSO co-solvent system can be used as a versatile alignment medium for the acquisition of high quality anisotropic NMR data for molecules of varying polarities.

Phase Transition Behavior of Main Chain Nematic Liquid-Crystalline Polymers Based on 2-methyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone and 2-tert-butyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone

2012 ◽  
Vol 1403 ◽  
Author(s):  
Christain Melchert ◽  
M. Behl ◽  
A. Lendlein
Keyword(s):  
Phase Transition ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Phase Transition Behavior ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Crystalline Polymers ◽  
Transition Behavior ◽  
X Ray Scattering

ABSTRACTThe control of phase transition behavior in liquid crystalline polymers could enable potential application in the field of actuators and sensors by enabling a higher actuator performance of liquid crystalline elastomers (LCE). In this context the phase transition behavior of siloxane based liquid crystalline copolymers synthesized from 1,1,3,3-tetramethyldisiloxane, 2-methyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone (M-MeHq), and 2-tert-butyl-1,4-bis[4-(4-pentenyloxy)benzoyl]hydroquinone (M-tBHq) was explored. The selected monomers provided different thermal stabilities of the nematic phase, while the non-flexible siloxane spacer suppressed a smectic phase. The mesogenic properties were studied by means of differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and wide angle X-ray scattering (WAXS). With increasing fraction of M-MeHq the nematic phase of the copolymer was stabilized and a tailoring of relatively low TNI was achieved.

Chromonic liquid crystalline nematic phase exhibited in binary mixture of two liquid crystals

2015 ◽  
Author(s):  
T. N. Govindaiah ◽  
H. R. Sreepad ◽  
K. N. Sridhar ◽  
G. R. Sridhara ◽  
N. Nagaraja
Keyword(s):  
Liquid Crystals ◽  
Binary Mixture ◽  
Nematic Phase ◽  
Liquid Crystalline

Study of the Liquid Crystalline Phases in Some Compounds of 4-Trans-(4-Alkyl)Cyclo-Hexylphenyl-Alkylcarboxylate

1983 ◽  
Vol 38 (12) ◽  
pp. 1362-1364 ◽  
Author(s):  
I. H. Ibrahim ◽  
W. Haase
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Intermolecular Distance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Enthalpy Changes ◽  
Liquid Crystalline Phases ◽  
Nematic Phases

Abstract Three mesogenic compounds of the general formula have been investigated by differential scanning calorimetry. thermal optical microscopy and X-ray diffraction methods/Enthalpy changes of The different phase transitions for these compounds have been determined. H33 exhibits smectic B and nematic phases, whereas H34 and H75 exhibit only smectic B phases. The thickness of the smectic layers and the average intermolecular distance have been evaluated, as well as the corresponding molecular parameters in the nematic phase.

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