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Effects of Electric Fields on Mixtures of Nematic and Cholesteric Liquid Crystals

  • E. F. Carr
  • J. H. Parker
  • D. P. McLemore

Abstract

This work involves nematic materials mixed with small amounts of cholesteryl acetate. It is assumed that the structures for these mixtures are similar to the cholesteric structure. The dielectric constant of p-methoxybenzylidene-p-cyanoaniline is greatest in a direction parallel to the long axes of the molecules; therefore, the structure for mixtures of this material with a cholesteric material can be changed to a nematic structure by applying external electric fields. NMR techniques and measurements of the dielectric loss at a microwave frequency are used to obtain information about the cholesteric-nematic phase transition as the external electric field and the concentration of cholesteryl acetate are varied. Although mixtures of p-[n-(p-methoxybenzylidene)-amino]-phenyl acetate and cholesteryl acetate cannot be changed to a nematic phase by employing electric fields because of the negative dielectric anisotropy, an ordering can be obtained with the screw axis of the helix parallel to a 300 kHz electric field.

Keywords

Nematic Phase Cholesteric Liquid Crystal Side Peak Dielectric Anisotropy Phenyl Acetate 
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.

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Footnotes and References

  1. 1.
    G. Friedel, Ann. Phys. (Paris) 18, 272 (1922)Google Scholar
  2. G. Friedel, Compte Rend. 17b, 475 (1923).Google Scholar
  3. 2.
    R.B. Meyer, Bull. Am. Phys. Soc. 14, 73 (1969)Google Scholar
  4. R.B. Meyer, Appl. Phys. Letters, 14, 208 (1969).CrossRefGoogle Scholar
  5. 3.
    G. Durand, L. Leger, F. Rondelez, and M. Veyssie, Phys. Rev. Letters, 22, 227 (1969).CrossRefGoogle Scholar
  6. 4.
    P.G. deGennes, Solid State Commun. 6, 163 (1968).CrossRefGoogle Scholar
  7. 5.
    R.B. Meyer, Appl. Phys. Letters 12, 281 (1968).CrossRefGoogle Scholar
  8. 6.
    E.F. Carr, Proceedings of the Second International Conference on Liquid Crystals, Kent, Ohio, August, 1968 (to be published)Google Scholar
  9. 7.
    J.J. Wysocki, J. Adams, and W. Haas, Phys. Rev. Letters 20, 1024 (1968).CrossRefGoogle Scholar
  10. 8.
    H. Baessler and M.M. Labes, Phys. Rev. Letters 21, 1791 (1968).CrossRefGoogle Scholar
  11. 9.
    E. Sackman, S. Meiboom, and L. Snyder, J. Am. Chem. Soc. 89, 5981 (1967).CrossRefGoogle Scholar
  12. 10.
    E. Sackmann, S. Meiboom, L. Snyder, A. Meixner, and R. Dietz, J. Am. Chem. Soc. 90, 3567 (1968).CrossRefGoogle Scholar
  13. 11.
    E.F. Carr, Advan. Chem. Series 63, 76 (1965).Google Scholar
  14. 12.
    E.F. Carr, E.A. Hoar, and W.T. MacDonald, J. Chem. Phys. 48, 2822 (1968).CrossRefGoogle Scholar
  15. 13.
    P.L. Jain, J.C. Lee, and R.D. Spence, J. Chem. Phys. 23, 878 (1955).CrossRefGoogle Scholar
  16. 14.
    E.F. Carr, J. Chem. Phys. 38, 1536 (1963).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1970

Authors and Affiliations

  • E. F. Carr
    • 1
  • J. H. Parker
    • 1
  • D. P. McLemore
    • 1
  1. 1.Physics DepartmentUniversity of MaineOronoUSA

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