scholarly journals OPTICAL AND THERMAL STUDIES ON NANO-MOLECULAR SELF-ASSEMBLED INDUCED SMECTIC PHASES OF LIQUID CRYSTALLINE MATERIALS.

2017 ◽  
Vol 5 (2) ◽  
pp. 1975-1980
Author(s):  
T.N. Govindaiah ◽  
◽  
B.N. Ramakrishna. ◽  
Keyword(s):  
Liquid Crystalline ◽  
Thermal Studies ◽  
Crystalline Materials ◽  
Smectic Phases ◽  
Self Assembled ◽  
Liquid Crystalline Materials ◽  
Induced Smectic Phases

Effective control of optical purity by chiral HPLC separation for ester-based liquid crystalline materials forming anticlinic smectic phases

2020 ◽  
pp. 1-11
Author(s):  
Terézia Vojtylová-Jurkovičová ◽  
Petra Vaňkátová ◽  
Magdalena Urbańska ◽  
Věra Hamplová ◽  
David Sýkora ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Optical Purity ◽  
Effective Control ◽  
Chiral Hplc ◽  
Hplc Separation ◽  
Crystalline Materials ◽  
Smectic Phases ◽  
Liquid Crystalline Materials

scholarly journals Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

2013 ◽  
Vol 9 ◽  
pp. 425-436 ◽  
Author(s):  
Alexej Bubnov ◽  
Miroslav Kašpar ◽  
Věra Hamplová ◽  
Ute Dawin ◽  
Frank Giesselmann
Keyword(s):  
Liquid Crystalline ◽  
Molecular Structures ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
Smectic Phases ◽  
Chiral Nematic ◽  
Nematic Phases ◽  
Liquid Crystalline Materials ◽  
Hydroxy Groups ◽  
Mesomorphic Properties

Several new calamitic liquid-crystalline (LC) materials with flexible hydrophilic chains, namely either hydroxy groups or ethylene glycol units, or both types together, have been synthesized in order to look for new functional LC materials exhibiting both, thermotropic and lyotropic behaviour. Such materials are of high potential interest for challenging issues such as the self-organization of carbon nanotubes or various nanoparticles. Thermotropic mesomorphic properties have been studied by using polarizing optical microscopy, differential scanning calorimetry and X-ray scattering. Four of these nonchiral and chiral materials exhibit nematic and chiral nematic phases, respectively. For some molecular structures, smectic phases have also been detected. A contact sample of one of the prepared compounds with diethylene glycol clearly shows the lyotropic behaviour; namely a lamellar phase was observed. The relationship between the molecular structure and mesomorphic properties of these new LCs with hydrophilic chains is discussed.

scholarly journals Polar columnar assemblies of subphthalocyanines

2020 ◽  
Vol 24 (01n03) ◽  
pp. 33-42
Author(s):  
Maria J. Mayoral ◽  
Tomás Torres ◽  
David González-Rodríguez
Keyword(s):  
Electric Fields ◽  
Liquid Crystalline ◽  
Review Article ◽  
Ferroelectric Polarization ◽  
Crystalline Materials ◽  
Self Assembled ◽  
Liquid Crystalline Materials

In this small review article, we provide an overview of the different self-assembled systems and materials created so far by rationally organizing fluorosubphthalocyanines in a non-centrosymmetric fashion, which allows access to novel polarly ordered liquid crystalline materials that can be aligned in the presence of electric fields and that exhibit permanent or switchable ([Formula: see text] ferroelectric) polarization.

scholarly journals Liquid Crystalline Copolymers Containing Sulfonic and Light-Responsive Groups: From Molecular Design to Conductivity

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2579
Author(s):  
Sakinah Mohd Alauddin ◽  
Nurul Fadhilah Kamalul Aripin ◽  
Thamil Selvi Velayutham ◽  
Alfonso Martinez-Felipe
Keyword(s):  
Liquid Crystalline ◽  
Molecular Design ◽  
Crystalline Materials ◽  
Structural Characterisation ◽  
Monomer Composition ◽  
Smectic Phases ◽  
Reversible Addition ◽  
Energy Conversion And Storage ◽  
Liquid Crystalline Materials ◽  
External Stimuli

In the search for novel smart multifunctional liquid crystalline materials, we report the synthesis, thermal and structural characterisation, and the conductivity, of a set of new block and statistical copolymers, containing light-responsive mesogenic groups (MeOAzB), polar sulfonic acids (AMPS), and methyl(methacrylate) groups (MMA). By using a cascade of reversible addition-fragmentation chain polymerisations, RAFT, we have tailored different side-chain polymeric structures by controlling monomer composition (MeOAzB/AMPS/MMA) and configuration. We have yielded simultaneous liquid crystalline behaviour and appreciable conductivity in polymers with low concentrations of polar acid groups, by the formation of smectic phases in narrow aggregates. The light-responsiveness of the polymers, via reversible trans-to-cis photoisomerization of azobenzene groups, and the local activation of conductivity at relatively low temperatures, opens the possibility to prepare polymer electrolytes for energy conversion and storage, whose conductivity could be controlled and optimised by external stimuli, including light irradiation.

scholarly journals Perhydroazulene-based liquid-crystalline materials with smectic phases

2012 ◽  
Vol 8 ◽  
pp. 403-410 ◽  
Author(s):  
Zakir Hussain ◽  
Henning Hopf ◽  
S Holger Eichhorn
Keyword(s):  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Core System ◽  
Crystalline Materials ◽  
Smectic Phases ◽  
Differential Scanning Colorimetry ◽  
Temperature Ranges ◽  
Nematic Phases ◽  
Liquid Crystalline Materials ◽  
Mesomorphic Properties

New liquid-crystalline materials with a perhydroazulene core were synthesized and the stereochemistry of these compounds was investigated. The mesomorphic properties of the new LC compounds were investigated by differential scanning colorimetry, polarizing optical microscopy and X-ray diffraction. We report here on the LC properties of nonchiral materials, which predominantly exhibit smectic phases and display nematic phases only within narrow temperature ranges. The dependence of the mesogenic behavior of the new materials on the stereochemistry of the core system was also investigated. All newly synthesized compounds were fully characterized by the usual spectroscopic and analytical methods.

Self-assembled liquid crystalline materials with fatty acids

2018 ◽  
Vol 132 (2) ◽  
pp. 989-1000 ◽  
Author(s):  
Sangeetha G. Bhat ◽  
Girish Sharada Ramachandra ◽  
Poornima Bhagavath ◽  
Mahabaleshwara Subrao ◽  
D. M. Potukuchi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Liquid Crystalline ◽  
Crystalline Materials ◽  
Self Assembled ◽  
Liquid Crystalline Materials

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

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