Effects of copper nanoparticles on the thermodynamic, electrical and optical properties of a disc-shaped liquid crystalline material showing columnar phase

Abstract

Thermodynamic, electrical and optical studies have been carried out on a discotic liquid crystal (DLC), namely 2, 3, 6, 7, 10, 11-hexabutyloxytriphenylene (possessing columnar phase) and its copper nanoparticles (0.6 wt%) based composite. The ionic conductivity of DLC–copper nanocomposite has increased by about two orders of magnitude as compared to the pure system. Dielectric permittivity has also increased. The absorption spectra for pure and nanocomposites have been studied by UV–Vis spectrophotometer. The optical study suggests that surface plasmon resonance has been introduced in DLC due to the incorporation of copper nanoparticles. It has been observed that the presence of nanoparticles has decreased the optical band gap to 3.3 eV from 4.2 eV of the pure DLC. Enhanced properties are useful for one-dimensional conduction and photovoltaic applications.

Keywords:

• liquid crystals
• columnar hexagonal phase
• aromatic cores
• homeotropic alignment
• ionic conductivity
• surface plasmons

Acknowledgements

P. Yaduvanshi thanks the Department of Information Technology (DIT) for junior research fellowship under the project.

Additional information

Funding

The work is financially supported by the Department of Information Technology (DIT) under project no. 12(6)/2011-EMCD.