Dielectric properties of mixtures of a bent-core and a calamitic liquid crystal.

Dielectric spectroscopy measurements have been performed on a bent-core nematic liquid crystal and on its binary mixtures with a calamitic nematic. We have detected more dispersions in the bent-core compound than in the calamitic one, including one at an unusually low frequency of a few kilohertz. The dispersions detected in the mixtures have been identified and the spectra have been split into contributions of the constituents. In order to connect the dielectric increment with the molecular dipole moment we have applied a sophisticated conformational calculation not performed before for a large, flexible mesogen molecule with numerous polar groups.

[1]  G. R. Luckhurst,et al.  Physical Properties of Liquid Crystals: Nematics , 2011 .

[2]  K. S. Krishnamurthy,et al.  Permittivity, conductivity, elasticity, and viscosity measurements in the nematic phase of a bent-core liquid crystal. , 2010, The journal of physical chemistry. B.

[3]  K. S. Krishnamurthy,et al.  Patterned electroconvective states in a bent-core nematic liquid crystal. , 2010, The journal of physical chemistry. B.

[4]  J. Gleeson,et al.  Rheological properties of bent-core liquid crystals , 2009 .

[5]  C. Zannoni,et al.  Ferroelectric Response and Induced Biaxiality in the Nematic Phase of Bent‐Core Mesogens , 2009 .

[6]  H. Takezoe,et al.  Electroconvection in nematic mixtures of bent-core and calamitic molecules. , 2009, Physical review. E, Statistical, nonlinear, and soft matter physics.

[7]  V. Domenici,et al.  Molecular motions of banana-shaped Liquid Crystals studied by NMR spectroscopy , 2008 .

[8]  Z. Varga,et al.  Electrically Tunable Color by Using Mixtures of Bent‐Core and Rod‐Shaped Molecules , 2008 .

[9]  J. Gleeson,et al.  Flexoelectric effect in a bent-core liquid crystal measured by Dynamic Light Scattering , 2008 .

[10]  W. Coffey,et al.  Rotational Diffusion and Dielectric Relaxation in Nematic Liquid Crystals , 2007 .

[11]  Badel L. Mbanga,et al.  Giant flexoelectricity of bent-core nematic liquid crystals. , 2006, Physical review letters.

[12]  A. Kocot,et al.  Orientational order and dynamics of the dendritic liquid crystal organo-siloxane tetrapodes determined using dielectric spectroscopy. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[13]  J. Gleeson,et al.  Critical behavior at the isotropic-to-nematic phase transition in a bent-core liquid crystal. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[14]  Y. Takanishi,et al.  Bent-Core Liquid Crystals: Their Mysterious and Attractive World , 2006 .

[15]  J. Gleeson,et al.  Nonstandard electroconvection in a bent-core nematic liquid crystal. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.

[16]  G. R. Luckhurst,et al.  Molecular theory of dielectric relaxation in nematic dimers. , 2004, The Journal of chemical physics.

[17]  A. Jákli,et al.  Ester‐type banana‐shaped monomers and investigations of their electro‐optical properties , 2002 .

[18]  G. R. Luckhurst,et al.  Dielectric relaxation in liquid crystalline dimers , 2001 .

[19]  S. Lagerwall,et al.  BROAD-BAND DIELECTRIC-RELAXATION SPECTROSCOPY OF A CHIRAL SMECTIC-B-CRYSTAL PHASE , 1994 .

[20]  Carlsson,et al.  Theoretical model of the frequency and temperature dependence of the complex dielectric constant of ferroelectric liquid crystals near the smectic-C*-smectic-A phase transition. , 1990, Physical review. A, Atomic, molecular, and optical physics.

[21]  H. Kresse,et al.  Dielectric Relaxation and Viscosity in a Mixture of Liquid Crystalline Substances , 1989 .

[22]  C. Druon,et al.  Characterization of the Sc Phase In a Liquid Crystal by Dielectric Relaxation , 1984 .

[23]  L. Bata,et al.  Dielectric dispersion measurements in a nematic liquid crystal mixture , 1975 .

[24]  Reinhard Pottel,et al.  N. E. Hill, W. E. Vaughan, A. H. Price und M. Davies: Dielectric Properties and Molecular Behaviour D. Van Nostrand. London, 1969. 480 Seiten. Preis: £ 6.10 , 1970, Berichte der Bunsengesellschaft für physikalische Chemie.

[25]  G. Meier,et al.  Eine einfache Theorie der dielektrischen Eigenschaften homogen orientierter kristallinflüssiger Phasen des nematischen Typs , 1961 .

[26]  J. Kirkwood.  The Dielectric Polarization of Polar Liquids , 1939 .

[27]  L. Onsager.  Electric Moments of Molecules in Liquids , 1936 .

[28]  M. Ferenets,et al.  Thin Solid Films , 2010 .

[29]  L. Bata.  Advances in liquid crystal research and applications , 1982 .

[30]  W. Kendall.  ROTATIONAL BROWNIAN MOTION AND DIELECTRIC THEORY , 1982 .

[31]  J. McConnell,et al.  Rotational Brownian motion and dielectric theory , 1980 .

[32]  A. Buka,et al.  Dielectric Relaxation in MBBA , 1979 .

[33]  N. E. Hill,et al.  Dielectric properties and molecular behaviour , 1969 .