Porous carbon nanoparticles dispersed nematic liquid crystal: influence of the particle size on electro-optical and dielectric parameters

ABSTRACT

Porous carbon nanoparticles (PCNPs) of four different sizes (~180 nm, ~51 nm, ~41 and ~25 nm) were dispersed into a nematic liquid crystal (NLC) in 0.25 wt% concentration. PCNPs were derived from biowaste materials and pyrolysed at elevated temperatures to get the porous structure. Polarising optical microscopic observations were carried out in dark and bright states on both the pure NLC as well as NLC-PCNPs composites. Homogeneous alignment was well maintained in all the composites except the one with the highest sized (~180 nm) PCNPs. Birefringence, relative permittivity and dielectric anisotropy, increases as the size of the PCNPs is decreased in the composites. The threshold voltage was also found to decrease with the decrease in the size of the PCNPs. Such investigations may be useful for the fabrication of display devices such as flat panel displays (FPDs) and phase shifters.

Graphical Abstract

KEYWORDS:

• Porous carbon nanoparticles
• nematic liquid crystal
• composite
• birefringence
• dielectric anisotropy
• electro-optical

Acknowledgments

We sincerely acknowledge Dr. Titilope Jayeoye for helping us in conducting nano characterizations. Thanks are also due to Dr. Jitendra Kumar for his useful discussions during this manuscript preparation.

Disclosure statement

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