Funct. Mater. 2017; 24 (2): 197-202.

doi:https://doi.org/10.15407/fm24.02.197

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

A.N.Samoilov1, S.S.Minenko1, A.P.Fedoryako2, L.N.Lisetski1, T.V.Bidna3

1Institute for Scintillation Materials, STC Institute for Single Crystals, National Academy of Sciences of Ukraine, 60 Nauky Ave., 61001 Kharkiv, Ukraine
2Dept. of Chemistry of Functional Materials, SSI Institute for Single Crystals, National Academy of Sciences of Ukraine, 60 Nauky Ave., 61001 Kharkiv, Ukraine
3Institute of Physics, National Academy of Sciences of Ukraine, 46 Nauky Ave., 03028 Kyiv, Ukraine

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.

Keywords: 
nematic liquid crystals, dielectric anisotropy, electrophysical properties.
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