Advertisement

Cylindrically Symmetric Textures in Mesophases of Cholesteryl Esters

  • Fraser P. Price
  • Chan S. Bak

Abstract

We have produced cylindrically symmetric single crystal textures of the cholesteric and smectic phases of cholesteryl esters by containing them in glass capillaries of smaller than 50 μ radius and inducing shear either by air-pressure changes from one end of the capillary or by volume changes on phase transformations of the sample itself. In the cholesteric phase, when the long axes of the molecules at the capillary interface are aligned parallel to the tube axis, the optic (twist) axes of the weakly negative uniaxial indicatrix are all radially oriented. In the smectic phase, when the molecules are aligned perpendicular to the substrate, the optic axes of the somewhat stronger positive uniaxial indicatrix are again radial. With the molecules aligned parallel to the tube axis, the optic axes of the smectic phase are everywhere parallel to the tube axis. These cylindrically symmetric orientations allow determination of the birefringence of the mesophase. The axial ratios of the refractive index ellipsoids are close to unity, for example, 1.014 and 1.028 respectively for the cholesteric and smectic phases of cholesteryl nonanoate. So far as we know these birefringences have been measured for the first time from cylindrical textures.

Keywords

Cholesteryl Ester Tube Axis Color Band Smectic Phase Pitch Change 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    B. Bottcher and G. Graber, Mol. Cryst. Liq. Cryst. 14, 1 (1971) .CrossRefGoogle Scholar
  2. 2.
    G. Pelzland H. Sackmann, Mol. Cryst. Liq. Cryst. 15, 75 (1971) .CrossRefGoogle Scholar
  3. 3.
    F. C. Frank, Discuss. Faraday Soc, 25, 19 (1958) .CrossRefGoogle Scholar
  4. 4.
    C. Williams, P. Pieranski and P. G. Cladis, Phys. Rev. Lett., 29, 90 (1972).CrossRefGoogle Scholar
  5. 5.
    P. G. deGennes, Mol. Cryst. Liq. Cryst. 12, 193 (1971) .CrossRefGoogle Scholar
  6. 6.
    F. P. Price and J. H. Wendorff, Mol. Cryst. Liq. Cryst., in press.Google Scholar
  7. 7.
    F. P. Price and J. H. Wendorff, J. Phys. Chem. 76, 276 (1972).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1974

Authors and Affiliations

  • Fraser P. Price
    • 1
  • Chan S. Bak
    • 1
  1. 1.University of MassachusettsAmherstUSA

Personalised recommendations