Effect of dielectric anisotropy on twisted nematics

Abstract

The electrical and optical threshold voltages for the twisted nematic field effect have been measured using Schiff base mixtures having Δε values from 2 to 16. The electrical threshold was measured by capacitance techniques, and was smaller than the optical threshold by a factor of ∼ 1.5. By using response time data to estimate changes in average elastic constants of the mixtures, the expected variation of the electrical threshold with Δε was found.