Physical properties of a bent-core nematic liquid crystal and its mixtures with calamitic molecules

A. Buka, N. Ber, K. Fodor-Csorba, A. Jákli, P. Salamon

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13 Citations (Scopus)

Abstract

This article summarizes the results obtained by various experimental methods on the physical properties of a bent-core nematic liquid crystal 4-chloro-1,3-phenylene bis-4-[4-(9-decenyloxy) benzoyloxy] benzoate (ClPbis10BB). The material exhibits unusual properties in all aspects tested. Its bend flexoelectric coefficient is 1000 times larger than in calamitics; it is viscoelastic with a large, shear-rate-dependent viscosity. Its bend and twist elastic constants are abnormally low; thus the nematic phase can be rendered to be a blue fog phase with a small amount of chiral dopant. It shows very high flow birefringence and unusually small leading Landau coefficient. It has two types of isotropic phases; at lower temperature it is probably tetrahedratic that can be transferred into the nematic phase with magnetic field. ClPbis10BB has a frequency-dependent conductivity anisotropy which is characterized by a double sign inversion. It exhibits various electroconvection (EC) patterns which are currently not understood in the frame of the standard theory of EC.

Original languageEnglish
Pages (from-to)872-887
Number of pages16
JournalPhase Transitions
Volume85
Issue number10
DOIs
Publication statusPublished - Oct 1 2012

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Keywords

  • bent-core nematic liquid crystal
  • dielectric spectroscopy
  • elastic constant
  • electroconvection
  • flexoelectricity
  • flow birefringence

ASJC Scopus subject areas

  • Instrumentation
  • Materials Science(all)

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