Enthalpies of Mixing in Binary Systems of Nematic Liquid Crystals

Abstract

The mixing enthalpies of binary mixtures of nematic liquid crystals are studied using a Calvet calorimeter. The systems studied are: 4-ethoxybenzylidene-4′-n-butylaniline-4-n-pentylphenyl-4′-methoxybenzoate and 4-n-butyl-4′-methoxyazoxybenzene-4-n-pentyl-4′-cyanobiphenyl. In the second system the induced smectic A phase occurs in the medium concentration range. The results are discussed in terms of molecular properties and interactions.

Key Words:

• nematic liquid crystals
• binary systems
• phase transitions
• induced smectic A phase
• enthalpy of mixing