Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their binary mixtures III. Binary mixtures of alkoxyphenyl arylates and arylalkoxybenzoates
作者:
MAGDI M. NAOUM,
GAMAL R. SAAD,
REFAAT I. NESSIM,
TALAL A. ABDEL AZIZ,
期刊:
Liquid Crystals
(Taylor Available online 1998)
卷期:
Volume 25,
issue 2
页码: 165-173
ISSN:0267-8292
年代: 1998
DOI:10.1080/026782998206308
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
4-Substituted phenyl-4-hexadecyloxybenzoates and 4-hexadecyloxyphenyl-4-substituted benzoates were prepared and thermally characterized by differential scanning calorimetry. Transition temperatures were identified by polarized-light microscopy. Substituents were chosen to cover a wide range of electronic and dipolar characteristics. Binary mixtures of different components were prepared and similarly characterized to construct their phase diagrams. In mixtures of the 4-CN and 4-NO2 analogues, enhanced SmA mesophases were found when either of these esters was mixed with one of the methoxy analogues. A weak molecular complex is proposed to account for this non-ideal solution behaviour. Linear or slightly enhanced mixture behaviours were found for the nitro or cyano derivatives when mixed with each other. The results are interpreted in terms of electronic, dipolar, and molecular interactions.
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