Reentrant Mesophases in Disc-Like Liquid Crystals
- 1 November 1984
- journal article
- liquid crystals
- Published by Taylor & Francis in Molecular Crystals and Liquid Crystals
- Vol. 111 (3-4) , 277-292
- https://doi.org/10.1080/00268948408072438
Abstract
The first case of reentrant phenomenon in disc-like mesogens was observed in hexaal-kanoyloxytruxenes (Cn HATX). In this series of ten compounds (n = 6 to 15) a few of them, the long chain ones, displayed a reentrant columnar phase. On the other hand, a reentrant ND nematic series was prepared: truxene P-alkoxybenzoates (Cn HBTX) with n = 6 to 14. Phase transitions between solid, mesomorphic and isotropic phases were studied by hot-stage microscopy and differential scanning calorimetry. Binary phase diagram studies, optical textural observations and X-ray measurements showed a rich polymorphism in these two series: a nematic disc-like phase (ND ), a hexagonal ordered columnar phase (Dho ), a hexagonal disordered columnar phase (Dhd ), a rectangular disordered columnar phase [Drd(P21/a) ] and a strongly tilted rectangular columnar phase [Drd(C2/m) ].Keywords
This publication has 9 references indexed in Scilit:
- An Homologous Series of Disc-Like Mesogens with Nematic and Columnar PolymorphismMolecular Crystals and Liquid Crystals, 1981
- Truxene DerivativesMolecular Crystals and Liquid Crystals, 1981
- Reentrant Phenomenon in Disc-Like Liquid CrystalMolecular Crystals and Liquid Crystals, 1981
- X-ray investigations and magnetic field effect on a nematic phase of disc-like moleculesJournal de Physique, 1981
- Reentrant nematic and columnar phases in disc-like liquid crystals at atmospheric pressureJournal de Physique Lettres, 1981
- On a “cholesteric” phase in disc-like mesogensPhysics Letters A, 1980
- X-Ray study of the reentrant polymorphism N-SA-N-SA in a pure liquid crystal compoundJournal de Physique, 1980
- Nematic disc-like liquid crystalsPhysics Letters A, 1979
- Crystalline arrangement of some disc like compoundsJournal de Physique Lettres, 1979