Liquid-crystalline polymorphism of 4-heptyloxybenzylidene-4?alkyloxyanilines and their phase equilibrium with 4-octyloxyphenyl 4-nitrobenzoate
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- 作者：Joanna Godzwon godzwonj@gmail.com ; Monika J. Sienkowska monika.sienkowska@usa.dupont.com ; Zbigniew Galewski ; zg@wchuwr.pl
- 关键词：Liquid crystals ; DSC ; POM ; Nematic ; Smectics ; Schiff bases ; Phase diagrams ; Phase transitions
- 刊名：Thermochimica Acta
- 出版年：2012
- 出版时间：10 March, 2012
- 年：2012
- 卷：531
- 期：Complete
- 页码：75-82
- 全文大小：1856 K
文摘
This paper describes the synthesis and liquid-crystalline properties of the homologous series of 4-heptyloxybenzylidene-4?alkyloxyanilines (7-n). Six of them are presented for the first time. Based on the polarization microscopy (POM and TOA methods) and the calorimetric (DSC) measurements following polymorphism has been detected: nematic, smectic C and smectic I mesophases. The presence of these mesophases was confirmed by the miscibility method, using 4-octyloxyphenyl 4-nitrobenzoate and terephtal-bis (4-butyloaniline) as a mesophase references.
Extraordinary results have been found in the mixtures of the investigated compounds with 4-octyloxyphenyl 4-nitrobenzoate; Induced smectic A has been observed, which is connected with very strong intermolecular interactions. Additionally destabilization of nematic and smectic C phases was visible.