Journal ArticleDOI
Synthesis and characterization of thiophene-containing liquid crystals
Reads0
Chats0
TLDR
In this article, the properties of liquid crystalline phases were investigated as a function of spacer units, number of aromatic core rings and different terminal moieties, and the polarity of terminal groups.Abstract:
Six series of liquid crystal materials containing a 2,5-disubstituted thiophene unit were synthesized. The liquid crystal compounds obtained were characterized by NMR, differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction techniques. The properties of liquid crystalline phases were investigated as a function of spacer units, number of aromatic core rings and different terminal moieties. Cyano, methoxy and iodo groups were used as terminal groups. It is found that: (i) compounds having one thiophene ring and one phenyl ring connected by an ester group, with a length/breadth value of 2.1, exhibit no mesophase, while other compounds containing two biphenyl rings, with a length/breadth ratio of 2.7, show mesophases; (ii) the polarity of terminal groups and the flexible spacer length significantly affect the thermal behaviour of these compounds; (iii) the nematic transition range of cyano-containing compounds decreases with increasing length of the flexible spacer, and long alk...read more
Citations
More filters
Journal ArticleDOI
Recent progress in luminescent liquid crystal materials: design, properties and application for linearly polarised emission
TL;DR: In this paper, the structure-property relationships for polarised emission and electroluminescence of liquid crystal materials are presented and discussed, with a focus on phosphorescent metallomesogens.
Journal ArticleDOI
Interactions between halloysite nanotubes and 2,5-bis(2-benzoxazolyl) thiophene and their effects on reinforcement of polypropylene/halloysite nanocomposites
TL;DR: 2,5-bis(2-benzoxazolyl) thiophene (BBT), capable of donating electrons, is selected as the interfacial modifier for polypropylene (PP)/halloysite nanotube (HNTs) composites and shows substantially increased tensile and flexural properties, which are attributed to the enhanced crystallinity of the nanocomposites.
Journal ArticleDOI
Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds and Ionic Liquids. Sublimation, Vaporization, and Fusion Enthalpies from 1880 to 2015. Part 2. C11–C192
TL;DR: A collection of phase change enthalpies of organic molecules including fusion, vaporization, and sublimation enthalphies for organometallic, ionic liquids, and a few inorganic compounds can be found in this paper.
Journal ArticleDOI
Novel liquid crystals based on [1]benzothieno[3,2- b][1]benzothiophene
Bedrˇich Kosˇata,Václav Kozmík,Jirˇí Svoboda,Vladimíra Novotná,Prˇemysl Vaneˇk,Milada Glogarová +5 more
TL;DR: In this paper, four series of new [1]benzothieno[3,2-b][1] benzothiophene derivatives have been synthesized, and the SmA-SmCA* phase transition was studied using DSC and dielectric spectroscopy.
Journal ArticleDOI
Total phase change entropies and enthalpies: An update on their estimation and applications to the estimations of amphiphillic fluorocarbon–hydrocarbon molecules
TL;DR: In this paper, a group additivity method was developed to estimate the total phase change entropies and enthalpies of organic solids and the results were compared to the fusion Entropies of 547 new measurements, and the method was expanded to also include estimations for 58 fluorinated compounds whose liquid phase at the melting point does not behave isotropically.
References
More filters
Book
Introduction to Liquid Crystals
TL;DR: In this paper, the authors present a model of the Nematic-Isotropic phase transition and its relation to the elastic continuuum theory of liquid crystals, which is used to describe the properties of liquid crystal structures.
Book
Thermotropic liquid crystals
TL;DR: In this article, the authors classify liquid crystal phases in relation to molecular structure materials requirements for Nematic and Chiral Nematic Electro-optical Displays Materials Requirements for Smectic Liquid Crystal Displays Cholesteric Materials for Surface Thermography Liquid Crystal Polymers.