Electro-optical, dielectric and optical properties of graphene oxide dispersed nematic liquid crystal composites

ABSTRACT

Graphene oxide (GO) in various concentrations (0.04 wt.%, 0.1 wt.% and 0.3 wt.%) was dispersed into nematic liquid crystal (LC) 5CB and studied for electro-optical, dielectric and optical responses. The textural and phase transition studies were investigated by optical polarising microscopy in the nematic phase. The effect of GO concentration on the micro-texture, phase transition temperatures, birefringence, threshold voltage, contrast ratio, dielectric permittivity, dielectric loss and conductivity was also investigated. The nematic–isotropic transition temperature slight increases (~3%) in the 0.04 wt.% and 0.1 wt.% GO dispersed 5CB composites as compared to 5CB. Threshold voltage decreases in the GO–5CB composites with the increase of GO concentration. Additionally, the effect of GO concentration on the optical absorbance of UV–visible light and energy bandgap is also considered.

Graphical Abstract

KEYWORDS:

• Nematic liquid crystals
• graphene oxide
• birefringence
• phase transitions
• threshold voltage

Acknowledgments

Financial support from DST, New Delhi (EMR/2016/003540) and CSIR, New Delhi 03(1451)/18/EMR-II in the form of research projects is deeply acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Department of Science and Technology [EMR/2016/003540].