Dielectric, optical and absorption studies of f-MWCNTs dispersed nematic liquid crystal

Abstract

Dielectric, conductivity, birefringence and UV-Vis spectral studies for functionalized multiwalled carbon nanotubes (f-MWCNTs) dispersed 4-methoxybenzylidene-4’-butylaniline (MBBA) liquid crystalline sample have been carried out. The variation of dielectric permittivity, relaxation loss factor and conductivity as a function of frequency for f-MWCNTs dispersed MBBA and pure MBBA sample has been reported. Relative permittivity value increases with the doping of MWCNT due to the π-π* interactions between host and dispersed molecules and local anchoring fields developed along the nematic director that collectively amplify the orientational order. The conductivity of the dispersed sample increased as f-MWCNTs concentration in pure MBBA sample increases. In the tan delta analysis, a variation in relaxation frequencies was observed for dispersed sample due to enhanced dielectric anisotropy. UV-Vis absorbance analysis reveals that after doping MWCNTs into pure NLC, the absorbance has increased. The birefringence was determined for both pure and dispersed systems, and an increase in its value for both dispersed systems has been reported.