The Physical Properties of the Cyanophenylcyclohexyl Ethanes (PECH)

Abstract

The physical properties of a new homologous series of stable, low-melting nematic materials, the cyanophenylcyclohexyl ethanes (PECH) are reported and compared with those of other stable, nematic materials. A broad range mixture is reported with a low viscosity, medium birefringence and large positive dielectric anisotropy. This mixture shows a high order parameter which increases the contrast of displays using dissolved pleochroic dyes. A comparison is also made between the structural isomers of PECH and PCH which questions the validity of molecular theories of elastic constants.