Molecular structure and chiral liquid crystalline phases

Abstract

We describe briefly some results obtained on both chiral and achiral compounds exhibiting chiral mesophases. We report the first example of a single component system exhibiting the undulated twist grain boundary C Ã or UTGB C Ã phase. Preliminary results concerning a few achiral compounds composed of banana-shaped molecules exhibiting a mesophase is reported. They have been investigated by polarized light optical microscopy, differential scanning calorimetry and x-ray diffraction studies.

Twisted-grain-boundary (TGB) phases:nanostructured liquid-crystal analogue of Abrikosov vortex lattices

“…It has been named UTGBC Ã phase by Pramod et al [60]. Sadashiva realized UTGBC Ã phase in a single-component system [61], and Yelamaggad et al realized it in a trimesogenic system joined together [62].…”

Optical and Thermal Studies on Nano-Molecular Self-Assembled Induced Smectic Phases of Liquid Crystalline Materials.

“…But in SmA phase the layer spacing's are almost constant. These variations are as shown in Figure 5 [15,16]. …”

“…The helical pitch measurements were performed on the cholesteric phase following the well-known Grandjean-Cano wedge method [16,17]. The given mixture was taken in a wedge-shaped cell treated for homogeneous alignment.…”

Study of Structural Patterns Exhibited by a Binary Mixture of Smectic and Cholesteryl Compounds

“…al., [12] have observed TGB-A phase in the mixtures of cholesteric and nematic compounds. Sadashiva [13] and Pramod et. al., [14] have observed a transition from TGB-A -TGB-C* in some pure and mixtures of the chiral liquid crystals.…”