Direct transition from a nematic phase to a polar biaxial smectic A phase in a homologous series of unsymmetrically substituted bent-core compoundsElectronic supplementary information (ESI) available: physical and spectral data obtained for the compounds of series 1j, 1k and 1l. See http://www.rsc.org/suppdata/jm/b3/b309262c/

2004 ◽  
Vol 14 (3) ◽  
pp. 310 ◽  
Author(s):  
R. Amaranatha Reddy ◽  
B. K. Sadashiva
Keyword(s):  
Spectral Data ◽  
Homologous Series ◽  
Nematic Phase ◽  
Supplementary Information ◽  
Direct Transition ◽  
Smectic A ◽  
Smectic A Phase

ANISOTROPY OF THE NEMATIC-SMECTIC A PHASE TRANSITION

1995 ◽  
Vol 09 (18n19) ◽  
pp. 2139-2155 ◽  
Author(s):  
BARBARA S. ANDERECK
Keyword(s):  
Phase Transition ◽  
Critical Behavior ◽  
Nematic Phase ◽  
Theoretical Work ◽  
Review Article ◽  
Superconducting Transition ◽  
Work Related ◽  
Smectic A ◽  
Smectic A Phase ◽  
Degree Of Anisotropy

Critical behavior at the transition from the nematic phase to the smectic A phase in liquid crystals has been of interest for over two decades. Discussions about the nature of the transition, its analogy to the superconducting transition, and the degree of anisotropy present in the critical exponents have been extensive during this time. This review article concentrates on the question of anisotropy at the nematic-smectic A transition. The experimental and theoretical work related to this question is summarized and compared. While progress has been made, there are many interesting questions related to this transition that remain for investigators to answer.

Structure and Thermal Behaviour of a Thermotropic Liquid Crystalline Polyimide (PI-LC)

1998 ◽  
Vol 10 (1) ◽  
pp. 147-153 ◽  
Author(s):  
M Tanaka ◽  
M Konda ◽  
M Miyamoto ◽  
Y Kimura ◽  
A Yamaguchi
Keyword(s):  
Phase Transition ◽  
Thermal Analysis ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Isotropic Phase ◽  
X Ray ◽  
Smectic A ◽  
Smectic C ◽  
Smectic A Phase

Anomalous solid structures formed by a thermotropic liquid crystalline polyimide (PI-LC) were investigated by thermal analysis, polarized light microscopy and x-ray analysis. It was revealed that PI-LC should undergo a phase transition from the crystalline to the isotropic phase through the smectic or nematic phase in the temperature range 277–300 °C. The PI-LC filament extruded at 280 °C, at which temperature the polymer was in liquid crystalline phase, was formed to have a structure similar to the smectic C phase, while that extruded and melt-drawn at 310 °C, at which temperature the polymer was in the isotropic phase, had a structure similar to the smectic A phase.

Local distortion energy and coarse-grained elasticity of the twist-bend nematic phase

Soft Matter ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 574-580 ◽  
Author(s):  
C. Meyer ◽  
I. Dozov
Keyword(s):  
Nematic Phase ◽  
Coarse Grained ◽  
Local Distortion ◽  
Coarse Grained Model ◽  
Smectic A ◽  
Smectic A Phase ◽  
Distortion Energy

We develop a coarse-grained model describing the macroscopic elasticity of the twist-bend nematic by analogy with the chiral smectic-A phase.

Dielectric Studies on Liquid Crystals under High Pressure: VI. Low Frequency Relaxation Process in the Nematic and Smectic A Phase of 4-n-Octyl-4'-Cyanobiphenyl (8 CB)

1994 ◽  
Vol 49 (4-5) ◽  
pp. 552-558 ◽  
Author(s):  
S. Urban ◽  
T. Brückert ◽  
A. Würflinger
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Low Frequency ◽  
Smectic A ◽  
Liquid Crystalline Phases ◽  
Smectic A Phase ◽  
Frequency Relaxation ◽  
Increasing Temperature

Abstract Dielectric relaxation studies of 4-n-octyl-4'-cyanobiphenyl (8 CB) were performed in the pressure range 0.1 -120 MPa, the frequency range 1 kHz -13 MHz and the temperature range 295-331 K. The dielectric behaviour of 8C B in the nematic phase is similar to that of 5 CB, 6 CB and 7 CB. In particular, the activation enthalpy decreases with increasing pressure and the activation volume decreases with increasing temperature in the nematic phase. In the smectic A phase of 8 CB both these parameters are markedly lower and show opposite pressure and temperature dependencies. We tentatively interpret these effects as a result of breaking of the dipole-dipole correlations which manifests itself differently in these liquid crystalline phases.

Biaxial smectic A phase in homologous series of compounds composed of highly polar unsymmetrically substituted bent-core molecules

2002 ◽  
Vol 12 (4) ◽  
pp. 943-950 ◽  
Author(s):  
B. K. Sadashiva ◽  
R. Amaranatha Reddy ◽  
R. Pratibha ◽  
N. V. Madhusudana
Keyword(s):  
Homologous Series ◽  
Smectic A ◽  
Smectic A Phase

Critical behaviour at the nematic–smectic A phase transition in a binary mixture showing induced nematic phase

RSC Advances ◽  
2014 ◽  
Vol 4 (38) ◽  
pp. 19861 ◽  
Author(s):  
Sudipta Kumar Sarkar ◽  
Malay Kumar Das
Keyword(s):  
Phase Transition ◽  
Binary Mixture ◽  
Nematic Phase ◽  
Critical Behaviour ◽  
Smectic A ◽  
Smectic A Phase

4(4-Alkyloxybenzoyloxy)-4' -cyanoazobenzole: Eine homologe Reihe flüssigkristalliner Verbindungen mit der ungewöhnlichen Phasenfolge smektisch A-nematisch-smektisch A / 4(4-Alkyloxybenzoyloxy)-4'-cyanoazobenzenes: A Homologous Series of Liquid Crystals Exhibiting the Unusual Phase Sequence Smectic A -Nematic -Smectic A

1980 ◽  
Vol 35 (11) ◽  
pp. 1384-1388 ◽  
Author(s):  
Gerd Heppke ◽  
Reinhard Hopf ◽  
Bernd Kohne ◽  
Klaus Praefcke
Keyword(s):  
Phase Transition ◽  
Homologous Series ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Alkyl Chain ◽  
Phase Region ◽  
Alkyl Chain Length ◽  
Smectic A ◽  
Phase Sequence ◽  
Phase Transition Temperatures

The synthesis and the phase transition temperatures of homologous liquid crystalline 4(4-alkyloxybenzoyloxy)-4'-cyanoazobenzenes with alkyl chain length n = 1-12 and n = 16 are reported. All compounds exhibit smectic A phases; the SA phase region being interrupted by a "re-entrant" nematic phase for alkyl chain lengath n ≥ 9.

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