Research on Various Display Properties of a Room-Temperature Twisted Nematic Display Material 6CHBT by Doping Single-Walled Carbon Nanotubes

Abstract

Present studies concentrate on the optical, dielectric, and electro-optical properties of single-walled carbon nanotubes (SWCNTs) doped in the nematic matrix of the liquid crystalline material 4-(trans-4¢-n-hexylcyclohexyl)isothiocyanatobenzene (6CHBT). 6CHBT is the nematic liquid crystalline substance that was employed in the investigation. SWCNTs having a diameter of around 0.8-1.4 nm and a length of about 100-300 nm have been inserted into it. For displays, the nematic liquid crystalline material 6CHBT is a perfect basis material due to its nematic phase temperature range of 12.5 - 43.0 °C. SWCNTs have been doped in 6CHBT in two different concentrations i.e., 0.01 and 0.02% (weight ratio). For higher concentrations, CNTs were observed to be bundled at different locations. For this reason, higher concentrations were not studied.  Using electro-optical and dielectric spectroscopy, the effects of SWCNTs doping on a number of display characteristics, including threshold voltage, dielectric anisotropy, and splay elastic constant, have been investigated. SWCNTs alignment parallel to the nematic direction is supported by the nematic phase. Nevertheless, in the nematic phase, the SWCNTs improve the molecules' local orientational arrangement. Consequently, the use of SWCNTs considerably reduces the threshold voltage required to change the geometry of the molecules from planar (bright state) to homeotropic (dark state).