首页   按字顺浏览 期刊浏览 卷期浏览 Comparison of Mesomorphic Behaviour and Electro-Optic Properties of Ferroelectric Mesog...
Comparison of Mesomorphic Behaviour and Electro-Optic Properties of Ferroelectric Mesogens With and Without Disiloxane End-Groups

 

作者: H.L. Owen,   J. Newton,   P. Hodge,   H.J. Coles,  

 

期刊: Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals  (Taylor Available online 1995)
卷期: Volume 265, issue 1  

页码: 563-575

 

ISSN:1058-725X

 

年代: 1995

 

DOI:10.1080/10587259508041723

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

Low molar mass liquid crystals with phase properties similar to polymers may be obtained by the addition of a disiloxane tail to an organic mesogen. We present a comparison of the properties of two chiral mesogens (based on the 4-((S)-(+) 2-Methylbutanoyloxy)phenyl 4-(9-decenyloxy)benzoate and 4-((2S)-2-Chloro-3- methylbutanoyl)phenyl 4′-(9-decenyloxy)benzoate moieties) with and without a pentamethyl disiloxane tail and with their vinyl-terminated analogues. We show a general decrease in transition temperatures, and a widening of the mesophase range in the disiloxane-substituted materials due to a suppression of the crystallisation temperature. The phases exhibited are modified, with a tilted smectic-C phase favoured on substitution of the disiloxane tail, eliminating the smectic-A phase found in the unsubstituted mesogen; this gives high tilt angle (28–36°) single mesophase materials. We summarise the electro-optic properties of a series of the disiloxane-substituted materials, which show low viscosity (∼500mPas) and moderate spontaneous polarisation (20–150nCcm−2) across the range of materials, and show their variation with temperature. We demonstrate the variations of these properties with varying alkyl spacer length, alkyl tail length and changing chiral end-group.

 

点击下载:  PDF (637KB)



返 回