Twist distortion in rod/liquid crystal mixtures

Abstract

A simple model is introduced to describe the twist distortion in mixtures of a rigid rod-like molecule (rod) and a liquid crystal (LC) molecule. We take into account the coupling between rods and LCs and calculate the equilibrium reorientation angles of rods and LCs when an external field applies. We find that the dependence of the critical threshold on the rod concentration is changed due to the ratio of the twist elastic constant K _22,2 to the dielectric or magnetic anisotropy χ₂ of the rod. The theory can qualitatively describe the observed properties of carbon nanotube/LC mixtures. We also discuss the reorientation dynamics.

Keywords:

• Freedericksz transition
• carbon nanotube
• liquid crystal
• rod
• distortion

Acknowledgements

This work was supported by a Grant-in-Aid for Scientific Research (C) (Grant No. 19540428) and that on the Priority Area ‘Soft Matter Physics’ (Grant No. 21015025) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.