Research Information System
Journal of the Faculty of Engineering and Architecture of Gazi University, vol.26, no.1, pp.213-221, 2011 (SCI-Expanded)
Especially with applications in display technology, liquid crystals have become the focus of great interest in recent years. Guest-host liquid crystal displays (GH-LCDs) are widely used because of their wide viewing angle, lower costs, excellent hues and high brightness levels. The aim of this study is to improve the molecular orientation and to examine effects on the nematic-isotropic phase transition temperature of dyes having different molecular structure and single walled carbon nanotubes used in GH-LCDs. For this purpose, three different dyes were separately doped to two different nematic liquid crystals and, their order parameters and phase transition temperatures were determined. At the second stage, single walled carbon nanotubes in different amounts were added to each of these solutions and the experiments were repeated as similar to previous ones. Although the order parameter had different values depending on dye, its maximal value was attained with anthraquinone structured dye. Addition of carbon nanotubes gave rise to different effects for each case. The dyes and nanotube did not significantly destabilize the mesomorphic phase of nematic hosts because the change in phase transition temperature stayed within limitations required.