Zvetkow Twist Viscosity Measurements of Some Nematic Liquid Crystals

Abstract

Abstract Zvetkow twist viscosity measurements are reported for a series of cyanobiphenyl liquid crystals and their eutectic mixtures in the nematic phase. The values obtained exhibit an odd-even variation. If the data are plotted against a reduced density, they divide into two groups, one corresponding to the odd and the other to the even series. This is attributed to effects of the configuration of the alkyl chain on the molecular packing density in the nematic phase. Using the Maier-Saupe theory, interaction energies are derived.