Investigation of dielectric and electro-optical properties of nematic liquid crystal with the suspension of biowaste-based porous carbon nanoparticles

ABSTRACT

The effect of biowaste porous carbon nanoparticles (PCNPs) on the dielectric and electro-optical properties of nematic liquid crystal (LC) mixture (1823A) of 4-(4-alkyl-cyclohexyl) benzene isothiocyanates and 4-(4-alkyl-cyclohexyl) biphenyl isothiocyanates has been studied. The dielectric permittivity of nematic LC has been increased with the dispersion of carbon NPs. The dielectric anisotropy has been calculated and found to be decreased with the dispersion of PCNPs into the pure nematic LC. The response time and birefringence have been also observed with the variation of temperature, frequency as well as the concentrations of carbon NPs. After the dispersion of PCNPs achieved better birefringence and faster response in the dispersed system, which is the significant application in display devices. Threshold voltage splay elastic coefficient and rotational viscosity have been calculated for both pure and NPs dispersed nematic system. Its value is increased with the dispersion of NPs. Additionally, photoluminescence and figure of merit have investigated as a comparative study of nematic matrix as well the dispersed system. The experimental results have been found to have good agreement with the theoretical data of nematic LC. An effort has been made to explain these experimental results on the basis of interaction between nematic molecules and carbon NPs.

Graphical Abstract

KEYWORDS:

• Nematic liquid crystal
• porous carbon nanoparticle
• relative permittivity
• dielectric anisotropy
• birefringence
• response time

Acknowledgments

The author is sincerely thankful for the Department of Science & Technology (DST), New Delhi [No. DST/INSPIRE Fellowship/2016/IF160572] for providing financial assistance in the form of INSPIRE Fellowship. The author Rajiv Manohar is grateful to UGC for the grant of a MID Career Award for date 22 March 2018 [No.F.19-224/2018 (BSR)]. The authors are also thankful to UPCST for the grant. Authors are also thankful to APJ Abdul Kalam Centre for Innovation for experimental facilities. One of the authors Dr Gurumurthy Hegde would like to thank DST-SERB, India for providing early career research grant with file No [ECR/2015/000190].

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The author is sincerely thankful for the Department of Science & Technology (DST), New Delhi [No. DST/INSPIRE Fellowship/2016/IF160572] for providing financial assistance in the form of INSPIRE Fellowship.