Derivation of extended Maxwell Garnett formula for carbon-nanotube-doped nematic liquid crystal

Abstract

A numerical effort for modelling the dielectric behaviour of the novel binary mixture of nematic liquid crystal and carbon nanotube (NLC:CNT) has been carried out using the Maxwell Garnett theory. The CNTs are treated as conductive anisotropic inclusions while the NLCs as dielectric isotropic or anisotropic matrix depending on temperature. Thus, the numerical expressions for the dielectric anisotropy for the scenarios of aligned CNTs in the NLC matrix of either nematic or isotropic phases have been derived, and the results show that the Debye parameter of CNT at optic limit seems to be the decisive factor in the enhancement of the dielectric anisotropy of the nematic system.

Keywords:

• nematic liquid crystal
• carbon nanotube
• Maxwell Garnett theory
• dielectric anisotropy

Acknowledgement

The authors acknowledge funding from the National Science Council of Taiwan (R.O.C) under Grant Nos. NSC 98–2112-M-006–001-MY3 and NSC 101–2112-M-006–011-MY3. The authors gratefully acknowledge Professors Tzong-Yueh Chen and Chuh-Yung Chen for empirical supports, Vickie Hui-Yu Lee, Ching-Han Yang and Dr. Ko-Ting Cheng for valuable discussion.