The flexoelectric behaviour of a hypertwisted chiral nematic liquid crystal

Citation
C. Noot et al., The flexoelectric behaviour of a hypertwisted chiral nematic liquid crystal, MOLEC CRYST, 366, 2001, pp. 2577
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Volume
366
Year of publication
2001
Database
ISI
SICI code
Abstract
The flexoelectric behaviour of a hypertwisted chiral nematic bimesogenic li quid crystal is presented. Through detailed electro-optic measurements, wit h particular emphasis on the switching properties, we demonstrate remarkabl y high optical axis tilt angles. The material studied possessed a room temp erature nematic phase and aligned easily on cooling under the application o f a moderate electric field. Switching times of the order of 500 mus and co ntrast ratios of 90:1 are readily achieved. The tilt angles, measured using the rotating analyser technique, were found to be practically temperature independent and linear with the applied field. Tilt angles of 22.5 degrees were obtained with moderate applied fields of 9.4 V/mum whilst fields of 25 V/mum yielded tilt angles of 45 degrees. We believe these are the highest tilt angles ever recorded for such fields.