Investigation of dielectric and optical properties of pure and diamond nanoparticles dispersed nematic liquid-crystal PCH5

ABSTRACT

In the present work, we have dispersed diamond nanoparticles (DNPs) in nematic liquid crystal 4-(Trans-4ʹ-n-Pentylcyclohexyl) Benzonitrile (PCH5) and studied the dielectric and optical properties of pure and DNPs dispersed nematic systems. We have investigated the effect of dispersion of DNPs (concentrations 0.5 and 1.0 wt%) in nematic liquid crystals (NLC) PCH5 on the dielectric permittivity, dielectric loss, dielectric anisotropy, photoluminescence, UV-Vis absorbance. It has been found that these properties are influenced by the dispersion of DNPs in nematic PCH5 system and applied electric field. Due to the dispersion of DNPs (1.0 wt% concentration) in PCH5, a significant decrease in the relative permittivity occurs. The relaxation peaks of dielectric loss shifts towards higher frequency side for NLC-DNPs composites. The dielectric anisotropy has been found to decrease with the dispersion of DNPs into pure NLC. The PL emission and UV-Vis absorbance for the dispersed systems have been decreased. An effort has been made to explain the observed results on the basis of interaction between nematic molecules and diamond NPs. The possible applications have also been suggested for the dispersed systems in this study.

GRAPHICAL ABSTRACT

KEYWORDS:

• Diamond nanoparticles
• nematic liquid crystal
• dielectric permittivity
• UV - Vis absorbance
• photoluminescence

Acknowledgments

DKG, AR and RM are grateful to UGC, New Delhi for the financial support. We are thankful to the Centre of Excellence at APJ Kalam Centre, University of Lucknow.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the University Grants Commission [21/06/2015(i)EU-V].