Spectrophotometry and electrical conductivity studies of multiwall nanotubes dispersed in nematic liquid crystals

Abstract

Optical transmission and electric conductivity were measured as a function of temperature for thin layers of multiwall nanotubes (MWNTs) dispersed in a mixture of cyanobiphenyl nematic liquid crystals (LC) ZhK-1282. At MWNT concentrations of 0.01-0.15 wt. % , characteristic changes in transmission at the nematic-isotropic phase transition temperature evidence that MWNTs integrate into LC matrix in a manner similar to that of the conventional non-mesogenic dopants. The electrical conductivity shows a percolation-like behaviour at ultra-low MWNTs loading of LC matrix below concentration levels of ~0.01 wt. % , which reflects the high aspect ratio of the conductive filler and the existence of strong interactions between LC matrix and MWNTs.