Twist grain boundary and blue phase in binary system of liquid crystalline materials

Abstract

The behaviour of one chiral mesogenic material with another mesogen in a mixed system has been investigated The mixture of chiral component having smectic Q phase and chiral antiferroelectric smectic C phase and non-chiral component having nematic and smectic C phases exhibits some interesting mesophases like blue phase, twist grain boundary phase, smectic A phase and smectic C phase, both on cooling the isotropic melt as well as on heating the crystalline material. The appearance of twist grain boundary phase and blue phase, which is studied by optical microscope, lies in a very narrow temperature and composition range. These phases are illustrated by their optical textures.