Unique effect of an electric field on a new liquid crystalline lactic acid derivative

Soft Matter ◽  
2015 ◽  
Vol 11 (23) ◽  
pp. 4649-4657 ◽  
Author(s):  
Vladimíra Novotná ◽  
Milada Glogarová ◽  
Miroslav Kašpar ◽  
Věra Hamplová ◽  
Lubor Lejček ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Electric Field ◽  
Acid Derivative ◽  
Applied Electric Field ◽  
Liquid Crystalline ◽  
Planar Texture ◽  
Unique Effect

A unique effect is observed in the TGBA phase under an applied electric field, which reversibly transforms the planar texture to a homeotropic one.

Comb-shaped liquid crystalline stereoregular cyclolinear methylsiloxane copolymer containing lactic acid derivative as chiral mesogenic side group

2013 ◽  
Vol 23 (6) ◽  
pp. 347-349 ◽  
Author(s):  
Irina M. Petrova ◽  
Maksim A. Shcherbina ◽  
Artem V. Bakirov ◽  
Sergei N. Chvalun ◽  
Nataliya N. Makarova
Keyword(s):  
Lactic Acid ◽  
Acid Derivative ◽  
Liquid Crystalline ◽  
Side Group

Rheological characterisation of a liquid-crystalline diol and its dependence with an applied electric field

2012 ◽  
Vol 39 (2) ◽  
pp. 191-197 ◽  
Author(s):  
M.T. Cidade ◽  
G. Pereira ◽  
A. Bubnov ◽  
V. Hamplova ◽  
M. Kaspar ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Liquid Crystalline

Nematic-to-columnar mesophase transition by in situ supramolecular polymerization

Science ◽  
2019 ◽  
Vol 363 (6423) ◽  
pp. 161-165 ◽  
Author(s):  
Keiichi Yano ◽  
Yoshimitsu Itoh ◽  
Fumito Araoka ◽  
Go Watanabe ◽  
Takaaki Hikima ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Electric Field ◽  
Applied Electric Field ◽  
Liquid Crystalline ◽  
Crystalline Material ◽  
Core Shell ◽  
Condensed Phases ◽  
Supramolecular Polymerization ◽  
Liquid Crystalline Material

Disk- and rod-shaped molecules are incompatible in coassembly, as the former tend to stack one-dimensionally whereas the latter tend to align in parallel. Because this type of incompatibility can be more pronounced in condensed phases, different-shaped molecules generally exclude one another. We report that supramolecular polymerization of a disk-shaped chiral monomer in nematic liquid crystals comprising rod-shaped molecules results in order-increasing mesophase transition into a single mesophase with a core-shell columnar geometry. This liquid crystalline material responds quickly to an applied electric field, resulting in unidirectional columnar ordering. Moreover, it can be modularly customized to be optoelectrically responsive simply by using a photoisomerizable rod-shaped module. The modular strategy allows for cooperative integration of different functions into elaborate dynamic architectures.

LIQUID CRYSTLASLIGHT SCATTERING BY FLUCTUATIONS INDUCED BY AN APPLIED ELECTRIC FIELD IN A NEMATIC LIQUID CRYSTAL (APAPA)

1972 ◽  
Vol 33 (C1) ◽  
pp. C1-63-C1-67 ◽  
Author(s):  
M. BERTOLOTTI ◽  
B. DAINO ◽  
P. Di PORTO ◽  
F. SCUDIERI ◽  
D. SETTE
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Applied Electric Field

Improved technique for measuring mechanical deformations induced by an applied electric field to an organic insulator

2012 ◽  
Vol 15 (2-3) ◽  
pp. 127-139
Author(s):  
Tung Tran Anh ◽  
Laurent Berquez ◽  
Laurent Boudou ◽  
Juan Martinez-Vega ◽  
Alain Lacarnoy
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Mechanical Deformations ◽  
Improved Technique

Synthesis and Properties of Biodegradable Liquid Crystalline Poly(ester-Urethane)s Based on Poly(L-Lactic Acid)

2013 ◽  
Vol 652-654 ◽  
pp. 459-462
Author(s):  
Ya Tong Guo ◽  
Zhu Zheng ◽  
Zhen Qi Hou ◽  
Jie Du
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Physical Properties ◽  
Liquid Crystalline ◽  
Degradation Rate ◽  
Hydrolytic Degradation ◽  
Hexamethylene Diisocyanate ◽  
Solution Polymerization ◽  
Phase Transition Temperatures

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(L-lactic acid) (PLLA), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and hydrolytic degradation were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate.

Solution for a Semi-Permeable Interface Crack in Elastic Dielectric/Piezoelectric Bimaterials

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
Q. Li ◽  
Y. H. Chen
Keyword(s):  
Electric Field ◽  
Mechanical Loading ◽  
Interface Crack ◽  
Applied Electric Field ◽  
Crack Tip ◽  
Crack Model ◽  
Permeable Crack ◽  
Impermeable Crack ◽  
Silicon Oil ◽  
Elastic Dielectric

A semi-permeable interface crack in infinite elastic dielectric/piezoelectric bimaterials under combined electric and mechanical loading is studied by using the Stroh complex variable theory. Attention is focused on the influence induced from the permittivity of the medium inside the crack gap on the near-tip singularity and on the energy release rate (ERR). Thirty five kinds of such bimaterials are considered, which are constructed by five kinds of elastic dielectrics and seven kinds of piezoelectrics, respectively. Numerical results for the interface crack tip singularities are calculated. We demonstrate that, whatever the dielectric phase is much softer or much harder than the piezoelectric phase, the structure of the singular field near the semi-permeable interface crack tip in such bimaterials always consists of the singularity r−1∕2 and a pair of oscillatory singularities r−1∕2±iε. Calculated values of the oscillatory index ε for the 35 kinds of bimaterials are presented in tables, which are always within the range between 0.046 and 0.088. Energy analyses for five kinds of such bimaterials constructed by PZT-4 and the five kinds of elastic dielectrics are studied in more detail under four different cases: (i) the crack is electrically conducting, (ii) the crack gap is filled with air/vacuum, (iii) the crack gap is filled with silicon oil, and (iv) the crack is electrically impermeable. Detailed comparisons on the variable tendencies of the crack tip ERR against the applied electric field are given under some practical electromechanical loading levels. We conclude that the different values of the permittivity have no influence on the crack tip singularity but have significant influences on the crack tip ERR. We also conclude that the previous investigations under the impermeable crack model are incorrect since the results of the ERR for the impermeable crack show significant discrepancies from those for the semi-permeable crack, whereas the previous investigations under the conducting crack model may be accepted in a tolerant way since the results of the ERR show very small discrepancies from those for the semi-permeable crack, especially when the crack gap is filled with silicon oil. In all cases under consideration the curves of the ERR for silicon oil are more likely tending to those for the conducting crack rather than to those for air or vacuum. Finally, we conclude that the variable tendencies of the ERR against the applied electric field have an interesting load-dependent feature when the applied mechanical loading increases. This feature is due to the nonlinear relation between the normal electric displacement component and the applied electromechanical loadings from a quadratic equation.

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