Ferroelectric and electroclinic characterisation of a new organic siloxane bimesogen
Authors:
- 1 November 1993
- journal article
- research article
- Published by Taylor & Francis in Ferroelectrics
- Vol. 148 (1) , 323-336
Abstract
A new siloxane based twin dimer has been synthesised which exhibits both a broad ferroelectric phase (from sub ambient temperatures to 37.5°C), and a Sa phase extending over 12.5°C (from 37.5°C to 50°C). The electroclinic effect within the Sa phase is very pronounced, occurs throughout the Sa phase and exhibits electroclinic coefficients as large as 2°/Vrms/μm at a temperature of Tsc*/Sa+5°C. The response times are correspondingly low (as little as 25μs at the end of the Sa range) and the maximum induced tilt angles very large, up to 17° at TSc*/sa+6°C and even higher closer to the phase transition. The effect of the soft mode contribution to the measured tilt angle can be seen far back into the ferroelectric phase. Characterisation has been performed by electro optic analysis, X ray studies, textural observations and measurement of spontaneous polarisation.Keywords
This publication has 13 references indexed in Scilit:
- Smectogenic dimeric liquid crystals. The preparation and properties of the α,ω-bis(4-n-alkylanilinebenzylidine-4′-oxy)alkanesLiquid Crystals, 1992
- A ferroelectric liquid crystal dimer: Synthesis and propertiesAdvanced Materials, 1992
- Ferroelectric liquid crystal siloxane homo and copolymersLiquid Crystals, 1991
- Switching behaviour and electro-optic response due to the soft mode ferroelectric effect in chiral smectic A liquid crystalsLiquid Crystals, 1991
- Synthesis and Electrooptical Properties of Terminal–Terminal Type of Ferroelectric Liquid CrystalChemistry Letters, 1990
- Measurement of the rotational viscosity of ferroelectric liquid crystals based on a simple dynamical modelLiquid Crystals, 1988
- Effect of Molecular Structure on Mesomorphism. 18.1Twin Dimers Having Methylene, Ethylene Oxide and Siloxane SpacersMolecular Crystals and Liquid Crystals, 1987
- Effect of molecular structure on mesomorphism. 12. Flexible-center Siamese-twin liquid crystalline diesters - a "prepolymer" modelJournal of the American Chemical Society, 1981
- Einfaches Verfahren zur Veresterung von CarbonsäurenAngewandte Chemie, 1978
- Electroclinic Effect at thePhase Change in a Chiral Smectic Liquid CrystalPhysical Review Letters, 1977