Title: Effect of nonmesogenic impurities on the liquid crystalline phase transitions of octylcyanobiphenyl
Authors: Denolf, Katleen ×
Cordoyiannis, George
Glorieux, Christ
Thoen, Jan #
Issue Date: 2007
Publisher: Published by the American Physical Society through the American Institute of Physics
Series Title: Physical Review E, Statistical, nonlinear, and soft matter physics vol:76
Article number: 051702
Abstract: The effect of the nonmesogenic solutes cyclohexane (CH), biphenyl (BP), and water (W) on the nematicisotropic
(N-I) and the nematic–smectic-A (N-SmA) phase transitions in the liquid crystal octylcyanobiphenyl
(8CB) has been studied by means of adiabatic scanning calorimetry. For BP and CH a linear decrease of both
transition temperatures was observed with increasing solute mole fraction. For water the transition temperature
stayed nearly constant (after a slight decrease for mole fractions of water up to 0.1) over the entire investigated
region. For all concentrations of biphenyl and water studied the N-SmA transition remains second order. For
8CB+CH, however, crossover from second order to first order is observed at a tricritical point of the mole
fraction x of CH around 0.046. For water it was found that for mole fractions of water above 0.1 phase
separation between an 8CB rich and a water rich phase occurred. The changes in the transition temperatures
and differences between the three systems, and in particular the crossover from second order to first order in
the 8CB+CH system, is explained in terms of a mean-field free energy density expression including coupling
terms of the solutes mole fraction with the nematic and smectic-A order parameters.
ISSN: 1539-3755
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Soft Matter and Biophysics
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
artikel_cg_Katleen_PRE76_2007.pdf Published 1115KbAdobe PDFView/Open


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science