Twisted grain boundary phase in the binary mixture of nematic and cholesteryl compounds.

The binary mixture of cholesteryl nonanoate (CN) and 4,4'-hexyloxy azoxy benzene (HOB) exhibit a very interesting mesophases like blue phase, twisted drain boundary (TCB) phase, induced smectic A, smectic C and smectic B phases at different temperatures when the mixture is coo led from isotropic phase. The existence of TGB phase is confirmed by DSC and optical microscopic studies. The mixtures with concentration 30 to 45% of CN exhibit TGB phase at higher temperature. The optical anisotropy of cholesteric phase is estimated. Numerous interesting optical textures are also illustrated