Electrical conductivity and dielectric constant measurements of liquid crystal-gold nanoparticle composites

The behaviour of the anisotropic electrical conductivity of liquid crystal-gold nanoparticle (LC-GNP) composites consisting of a commercially available room temperature nematic compound doped with alkylthiol-capped GNPs has been investigated. The nematic-isotropic transition of the composite decreases nearly linearly with increasing X, the concentration of GNP ( in weight %) at a rate of about 1 degrees C/weight%. The inclusion of GNPs increases the electrical conductivity of the system with the value increasing by more than two orders of magnitude for X=5%. However, the anisotropy in conductivity, defined as the ratio of the conductivity along (sigma(parallel to)) and orthogonal (sigma(perpendicular to)) to the director shows a much smaller but definite decrease as X increases.