DIELECTRIC, VISCOUS, AND ELASTIC PROPERTIES OF MESOGENIC 4-n-HEXYLOXY-4'-CYANOBIPHENYL
G. Czechowski and J. Jad┐yn
Institute of Molecular Physics, Polish Academy of Sciences Smoluchowskiego 17, 60-179 Pozna˝, Poland
Full Text PDF
Received: January 22, 2001
The paper presents the results of measurements of the static and dynamic electric permittivity, the shear viscosity, and the splay and bend elastic constants for 4-n-hexyloxy-4'-cyanobiphenyl (C6H13O-Ph-Ph-C≡N). On the basis of the static values of the nematic principal permittivities, ε||(T) and ε(T), the angle between the dipole moment vector and the long axis of 4-n-hexyloxy-4'-cyanobiphenyl molecule, the apparent dipole moment and the nematic order parameter were determined. From the temperature dependences of the dielectric relaxation time (corresponding to the molecular rotation around the short axis) and the shear viscosity, the strength of the nematic potential and the effective length of 4-n-hexyloxy-4'-cyanobiphenyl molecule (in isotropic phase) were estimated. The K11 and K33 elastic constants were determined from the voltage dependence of the capacitance of the planar nematic cell with the method proposed by Gruler et al. and Uchida et al.
DOI: 10.12693/APhysPolA.99.579
PACS numbers: 64.70.Md, 77.84.Nh, 77.22.Gm, 66.20.+d