Impact of dispersed graphene oxide on thermodynamical, optical, electro optical and dielectric properties of nematic liquid crystal

ABSTRACT

Colloidal suspension of 8CB dispersed with graphene oxide has been prepared. Differential scanning calorimetry scans have been performed for both pure and graphene oxide dispersed samples. The Cr-SmA, SmA-N and N-I transition temperature have been reduced in graphene oxide dispersed sample. Textures have also been recorded in nematic and smectic phases for pure and dispersed samples. Optical studies have been carried out with UV-Visible spectrophotometer in order to determine optical band gap of the samples. Increased optical band gap for nanocomposite has been observed. Increased threshold voltage, splay elastic constant and rotational viscosities have been observed for dispersed nanocomposite. Furthermore, dielectric studies have been carried out for both homeotropic and planar alignment of molecules. Dielectric anisotropy has been found to be increased in the dispersed sample. Observed value of conductivity for graphene oxide dispersed nanocomposite is lower in the smectic phase while it is higher in the nematic phase. Relaxation phenomenon shifts to low frequency for graphene oxide dispersed nanocomposite as compared to the pure sample.

Graphical abstract

KEYWORDS:

• Liquid crystals-nanocomposite
• dielectric anisotropy
• electro-optical study
• permittivity

Acknowledgments

We wish to thank DST, New Delhi, for financial support to the Centre under FIST programme. One of us (PKS) thanks the University Grants Commission, New Delhi, for support through a University Research Fellowship.

Disclosure statement

No potential conflict of interest was reported by the author(s).