Electrooptical properties of carbon-nanotube-doped twisted nematic liquid crystal cell

We investigated the electrooptical properties of a carbon nanotube (CNT)-doped twisted nematic (TN) liquid crystal (LC) cell. Experimental results reveal that the doped CNTs influence the elastic constant of LC-CNT dispersion. Using a small amount of CNT dopant, the field-on response time of the LC cell is nearly invariant; the threshold voltage of the cell increases due to the increase in the elastic constant of LC-CNT dispersion. At a higher CNT concentration, the marked increase in the dielectric anisotropy of LC-CNT dispersion markedly decreases the field-on response time and threshold voltage of the LC cell. The field-off response time of this cell decreases with increasing CNT concentration due to the increase in elastic constant and the slight increase in viscosity of LC-CNT dispersion. The field-on and field-off response times of the LC cell are reduced simultaneously when the LC host is doped with a moderate amount of CNT dopant.