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Pramana

, Volume 23, Issue 5, pp 639–643 | Cite as

Optical anisotropy of some cholesteryl esters of fatty acids

  • H S Subramhanyam
  • Upkar Singh Hunjan
Liquid Crystals

Abstract

Assuming the Neugebauer relations to be valid we have made calculations with regard to the effective polarizabilities and hence the optical anisotropy in smectic and cholesteric mesophases of five cholesteryl esters of fatty acids. The variation of optical anisotropy as a function of temperature and the change in optical anisotropy as we pass from the lowest temperature in the smectic phase to the lowest temperature of the cholesteric phase are correlated with the number of C-C bonds in the alkyl end groups of the molecules. It emerges that the end groups do not contribute significantly to the effective optical anisotropy owing to the existence of rotational isomerism.

Keywords

Optical anisotropy cholesteryl esters fatty acids Neugebauer relations smectic phase cholesteric phase rotational isomerism 

PACS No.

61·30 V 

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Copyright information

© Indian Academy of Sciences 1984

Authors and Affiliations

  • H S Subramhanyam
    • 1
    • 2
  • Upkar Singh Hunjan
    • 1
  1. 1.Kenyatta University CollegeNairobi
  2. 2.Department of PhysicsManasagangotri, MysoreIndia

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