Showing papers by "S. Chandrasekhar published in 1985"
TL;DR: In this paper, the activation energy for low frequency dielectric relaxation in the nematic and smectic A phases, near-neighbor correlation and some of its consequences, e.g., reentrant polymorphism, and the possibility of producing new kinds of thermotropic phases, by bridging the gap between rod-like and disk-like mesogens, are discussed briefly.
Abstract: The paper draws attention to a few selected problems that are of interest from the molecular point of view. In particular, the following topics are discussed briefly: (i) the activation energy for low frequency dielectric relaxation in the nematic and smectic A phases, (ii) near-neighbor correlation and some of its consequences, e.g., reentrant polymorphism, and (iii) the possibility of producing new kinds of thermotropic phases, e.g., biaxial nematics and discotic smectics, by bridging the gap between rod-like and disk-like mesogens.
51 citations
TL;DR: In this article, pressure-temperature diagrams have been studied for two discotic compounds, hexa-n-octyloxytriphenylene and hexa n-decanoyloxide trioxide, which exhibit columnar (D) phase at atmospheric pressure.
Abstract: Pressure-temperature diagrams have been studied for two discotic compounds, hexa-n-octyloxytriphenylene and hexa-n-decanoyloxytriphenylene, both of which exhibit the columnar (D) phase at atmospheric pressure. Two interesting results, common to both compounds, have been obtained: (a) in contrast to what is usually observed in liquid crystals of rod-like molecules, the columnar-isotropic (D-I) transition, which is enantiotropic at atmospheric pressure, becomes monotropic at high pressures; (b) dT/dP ≈ 0 for theD-I transition, implying that despite the drastic change in the molecular order at this transition, the associated volume change is extremely small.
4 citations