TITLE

A non-isothermal activated kinetics of K-SmA transition of the aligned octylcyanobiphenyl

AUTHOR(S)
Sharma, D.
PUB. DATE
July 2012
SOURCE
Journal of Thermal Analysis & Calorimetry;Jul2012, Vol. 109 Issue 1, p331
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
This study explores a non-isothermal activated kinetics of the Crystalline to Smectic A (K-SmA) transition of the aligned octylcyanobiphenyl (8CB) liquid crystal. High resolution calorimetric technique was used to study the molecular motion and rearrangement of the 8CB molecules near the K-SmA transition as a function of temperature, rate, and time. In the presence of magnetic field, the transition peak was found to be shifted towards lower temperature by 0.5 K when compared with results of un-magnetized 8CB. The K-SmA transition showed a rate dependent kinetics following Arrhenius behavior where the increased shifting rate showing an increased thermal kinetics for the transition. The 8CB molecules get more aligned and more ordered that pushes the temperature of the transition towards lower temperature in the presence of magnetic field. Hence they show a temperature decrease in the peak of the transition temperature with a decrease in the enthalpy and hence needs more activation energy. This study may be useful to understand the liquid crystal behavior to upgrade liquid crystal devices (LCDs).
ACCESSION #
76447138

 

Related Articles

  • An atomistic description of the nematic and smectic phases of 4-n-octyl-4′ cyanobiphenyl (8CB). Palermo, Mattia Felice; Pizzirusso, Antonio; Muccioli, Luca; Zannoni, Claudio // Journal of Chemical Physics;May2013, Vol. 138 Issue 20, p204901 

    We report the results of atomistic molecular dynamics simulations of 4-n-octyl-4′ cyanobiphenyl (8CB) on samples of 750 and 3000 molecules showing the spontaneous formation of the nematic phase and then of smectic layers by gradually cooling down from the isotropic phase. Orientational,...

  • Strongly nonlinear dynamics of ferroelectric liquid crystals. Jeżewski, W.; Śliwa, I.; Kuczyński, W. // European Physical Journal E -- Soft Matter;Jan2013, Vol. 36 Issue 1, p1 

    Molecular reorientation processes induced in thin ferroelectric liquid crystal systems by strong alternating external electric fields are studied both by solving numerically the equation of reorientation motion of molecules and by measuring the electro-optic response of thin samples. It is shown...

  • Structure of Ï€- and 2Ï€-Walls in Smectic films. Dolganov, P.; Dolganov, V.; Cluzeau, P. // JETP Letters;Nov2012, Vol. 96 Issue 5, p317 

    The structure of π- and 2π-walls in smectic films was reconstructed from optical reflectivity measurements. Investigations were made in free standing films of nonpolar Smectic- C and ferroelectric Smectic- C* liquid crystals. π-walls are observed in magnetic field and 2π-walls in...

  • Squeezing-out dynamics in free-standing smectic films. Zakharov, A. V.; Śliwa, Izabela // Journal of Chemical Physics;2015, Vol. 142 Issue 21, p1 

    We have carried out a theoretical study of the dynamics of the removal of one smectic layer from the N-layer free-standing smectic film during the layer-thinning process. Squeezing-out is initiated by a thermally activated nucleation process in which a density fluctuation forms a small hole. The...

  • A novel model for smectic liquid crystals: Elastic anisotropy and response to a steady-state flow. Püschel-Schlotthauer, Sergej; Turrión, Victor Meiwes; Stieger, Tillmann; Grotjahn, Robin; Hall, Carol K.; Mazza, Marco G.; Schoen, Martin // Journal of Chemical Physics;2016, Vol. 145 Issue 16, p164903-1 

    By means of a combination of equilibrium Monte Carlo and molecular dynamics simulations and nonequilibrium molecular dynamics we investigate the ordered, uniaxial phases (i.e., nematic and smectic A) of a model liquid crystal. We characterize equilibrium behavior through their diffusive behavior...

  • Existence of time lag in crystalline to smectic A (K-SmA) phase transition of 4-decyl-4-biphenylcarbonitrile (10CB) liquid crystal. McDonough, Kris; Vy, Ngoc; Sharma, Dipti // Journal of Thermal Analysis & Calorimetry;Jun2014, Vol. 116 Issue 3, p1515 

    This study explores the presence of time lag in crystalline to smectic A (K-SmA) phase transition of 4-decyl-4-biphenylcarbonitrile (10CB) liquid crystal. A non-isothermal heating and cooling study were performed for 10CB liquid crystal using calorimetric technique where heating scan was...

  • Synthesis and Thermotropic Studies of a New Series of Teraryl Liquid Crystals 2-(4'-Alkoxybiphen-4-yl)-5-Cyanopyridines. Win-Long Chia; Xue-Ming Lin // International Journal of Molecular Sciences;Sep2013, Vol. 14 Issue 9, p18809 

    A new series of teraryl 2-(4'-alkoxybiphen-4-yl)-5-cyanopyridines (nO-PPPyCN, n = 2-8) compounds, bearing a cyanopyridine terminus, were synthesized using a short 2-step reaction with overall yields between 33% and 69%. Spectral analyses were in accord with the expected structures. Thermotropic...

  • Use of dielectric spectroscopy for evidencing subphases in an antiferroelectric liquid crystal. Marino, Lucia; Ionescu, Andrei Th.; Pucci, Daniela; Marino, Salvatore; Bruno, Emanuela; Scaramuzza, Nicola // Journal of Applied Physics;2014, Vol. 116 Issue 11, p114101-1 

    The analysis of an orthoconic antiferroelectric liquid-crystalline mixture, using dielectric spectroscopy, has revealed a plurality of ferroelectric smectic C* subphases. A great variety of relaxation responses that could indicate the presence of different SmC* subphases has been observed with...

  • Study of the smecticA-hexaticB phase transition in homeotropic single domain samples of 65OBC liquid crystal by photopyroelectric calorimetry. Mercuri, F.; Paoloni, S.; Marinelli, M.; Pizzoferrato, R.; Zammit, U. // Journal of Chemical Physics;Feb2013, Vol. 138 Issue 7, p074903 

    The smecticA-hexaticB phase transition was studied in a homeotropic single domain sample and in a non-aligned sample of n-hexyl-4′-n-pentyloxybiphenyl-4-carboxylate liquid crystal compound to probe the effect of different amount of defects on the phase transition. The specific heat, the...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics