Hostname: page-component-6bf8c574d5-rwnhh Total loading time: 0 Render date: 2025-02-18T06:38:18.319Z Has data issue: false hasContentIssue false
  • English
  • Français

Synchrotron X-Ray Radiation (CHESS) Study of Electric-Field Induced Changes in the Structure of Thermotropic Side-Chain Liquid Crystals

Published online by Cambridge University Press:  15 February 2011

T. J. Bunning ,
S. G. McNamee ,
C. M. McHugh ,
S. S. Patnaik ,
C. K. Ober  and
W. W. Adams
T. J. Bunning
Affiliation:
WL/MLPJ, Wright-Patterson AFB, OH 45433
S. G. McNamee
Affiliation:
Dept. of MS&E, Cornell University, Ithaca, NY 14853
C. M. McHugh
Affiliation:
WL/MLPJ, Wright-Patterson AFB, OH 45433
S. S. Patnaik
Affiliation:
WL/MLPJ, Wright-Patterson AFB, OH 45433
C. K. Ober
Affiliation:
Dept. of MS&E, Cornell University, Ithaca, NY 14853
W. W. Adams
Affiliation:
WL/MLPJ, Wright-Patterson AFB, OH 45433
Get access

Abstract

Synchrotron radiation from the Cornell High Energy Synchrotron Source (CHESS) was used to probe the alignment kinetics of a class of thermotropic siloxane-based liquid crystals under the influence of an electric field. The high flux allows for real-time investigation of microstructural changes as a function of frequency and temperature. The packing behavior of a pentamethylcyclosiloxane ring with pendant biphenyl mesogens was thoroughly investigated. The director orientation parameter, Sd, typically increased with decreasing temperature and was not strongly affected by frequency. Electric-field induced changes in the director orientation were also monitored. Upon application of an electric field, the nematic system exhibited a tendency to pack in columns with short-range correlation of the mesogens. Column correlation lengths are examined as a function of temperature for two frequencies. At the low temperature end of the mesophase, a tendency for the mesogens to layer pack was observed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 307: Symposium L – Applications of Synchrotron Radiation Techniques to Materials Science , 1993 , 311
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Haase, W., Pranato, H., and Brmuth, F. J., Ber. Bunsenges. Phys. Chem. 89, 1229 (1985).CrossRefGoogle Scholar
2. Haase, W. and Pranato, H., Progr. Colloid & Polymer. Sci. 69, 139 (1984).Google Scholar
3. Pranato, H. and Haase, W., Mol. Cryst. Liq. Cryst. 98, 99 (1983).Google Scholar
4. Haase, W. and Pranato, H., in Polymeric Liquid Crystals, edited by Blumstein, A., (Plenum, New York, 1985) pp. 313.CrossRefGoogle Scholar
5. Attard, G. S., Mol. Phys. 58, 187 (1986).Google Scholar
6. Anwer, A. and Windle, A. H., Polymer 32, 103 (1991).Google Scholar
7. Ober, C. K. and Delvin, A., J. Polym. Sci. Part B. Polym. Phys. 28, 1047 (1990).Google Scholar
8. Delvin, A., Ober, C. K., and Bluhm, T. L., Macromolecules 22, 498 (1989).Google Scholar
9. Bunning, T. J., Klei, H. E., Samulski, E. T., Ober, C. K., and McNamee, S.G., Polym. Prep. 33, 315 (1992).Google Scholar
10. Kozak, A., Simon, G. P., and Williams, G., Polym. Commun. 30, 102 (1989).Google Scholar
11. Davidson, P. and Levelut, A. M., Liq. Cryst. 11, 469 (1992).Google Scholar