Mixtures of 4-pentyl-4'-cyanobiphenyl and photosensitive azoxy nematics as hosts for liquid crystal dispersions of carbon nanotubes

Abstract

In mixtures of nematic liquid crystals with opposite signs of dielectric anisotropy (4-n-pentyl-4'-cyanobiphenyl (5CB), Δε>>0, and azoxy nematic ZhK440, Δε << 0), anomalous behavior of optical transmission and electrophysical properties was observed at concentrations close to the compensation point. The observed features, which could be ascribed to enhancement of the director fluctuations, were suppressed by addition of small amounts (~0.04 %) of dispersed carbon nanotubes. In such systems, it is possible to realize the Freedericks transition at relatively small (~15 %) concentration of 5CB, preserving the possibility of UV-induced effects due to trans-cis isomerization of azoxy nematics.