Viscous Properties and Dynamic Electrooptical Performance in Twisted Nematic Displays of Several Liquid Crystal Classes

The temperature dependence of the rotational viscosities of several physically markedly different binary mixtures belonging to ten different liquid crystal classes is measured. An attempt is made to correlate the results with class-specific structural properties such as hydrogenated rings, molecular polarity and structure of flexible side-chains. It is show that the measured smallscale dynamic properties of twist cells compare well with approximative theoretical calculations and experimentially determined class-specific material parameters. For the switching times corresponding to large-scale twist deformations heuristic approximations lead to satisfactory results.