Determination of Viscoelastic Properties in a Chiral Smectic C* Liquid Crystal Using Different Methods

Abstract

The viscoelastic properties belong to the most important properties of chiral smectic liquid crystals. In this paper different methods for determination of viscoelastic properties of chiral smectic liquid crystals are compared. All of them belong to small deformation methods. The importance of the director alignment in the sample for determination of the bulk elasticity and viscosity coefficients is described. Using a typical ferroelectric in the chiral smectic C* phase we demonstrated that the correct bulk values of mentioned material constants can be determined using thick, homeotropically aligned samples only.

Keywords:

• Chiral liquid crystal
• dielectric method
• elasticity
• electrooptic method
• viscosity

Acknowledgment

This work was supported by the funds for science in the years 2007–2010 as a research project.