The University of Southampton
University of Southampton Institutional Repository

NMR determination of the physical properties of nematics

NMR determination of the physical properties of nematics
NMR determination of the physical properties of nematics
Certain physical properties of nematics can be obtained from the field-induced static and dynamic director orientations in thin films. Here we describe how deuterium nuclear magnetic resonance (NMR) spectroscopy can be used to investigate the field-induced director orientation in nematic liquid crystals. This powerful approach is illustrated with specifically deuteriated 4-pentyl-4'-cyanobiphenyl (5CB) subject to the magnetic field of the spectrometer and an electric field applied at an angle to it. A series of deuterium NMR spectra was acquired as a function of the applied electric field, which can be used to explore the static director orientation. When the electric field is applied to the nematic, the director moves from being parallel to the magnetic field to being at an angle to it (the turn-on process) because Delta epsilon and Delta chi are both positive for 5CB. After the electric field is switched off, the director relaxes back to being parallel to the magnetic field (the turn-off process). Deuterium NMR spectra were recorded during the turn-on and the turn-off alignment processes as a function of time. Analysis of these results for the static and dynamic experiments, based on the predictions of continuum theory, provides the physical properties of the nematic.
induced director dynamics, magnetic-resonance spectroscopy, liquid-crystal, orientational order, phase, reorientation, polymer, 4-octyl-4'-cyanobiphenyl, behavior
1366-5855
1389-1396
Luckhurst, G.R.
7807d1c6-54a1-414f-9abe-22de4d9c30f7
Sugimura, A.
ad404617-1e0f-445f-84d4-1f7efdf57909
Timimi, B.A.
a1aa2a58-5d7a-4c22-9339-b8ed8e81d053
Zimmermann, H.
559ddd30-a833-4cf0-a67e-b7b53bbfba17
Luckhurst, G.R.
7807d1c6-54a1-414f-9abe-22de4d9c30f7
Sugimura, A.
ad404617-1e0f-445f-84d4-1f7efdf57909
Timimi, B.A.
a1aa2a58-5d7a-4c22-9339-b8ed8e81d053
Zimmermann, H.
559ddd30-a833-4cf0-a67e-b7b53bbfba17

Luckhurst, G.R., Sugimura, A., Timimi, B.A. and Zimmermann, H. (2005) NMR determination of the physical properties of nematics. Liquid Crystals, 32 (11-12), 1389-1396. (doi:10.1080/02678290500124692).

Record type: Article

Abstract

Certain physical properties of nematics can be obtained from the field-induced static and dynamic director orientations in thin films. Here we describe how deuterium nuclear magnetic resonance (NMR) spectroscopy can be used to investigate the field-induced director orientation in nematic liquid crystals. This powerful approach is illustrated with specifically deuteriated 4-pentyl-4'-cyanobiphenyl (5CB) subject to the magnetic field of the spectrometer and an electric field applied at an angle to it. A series of deuterium NMR spectra was acquired as a function of the applied electric field, which can be used to explore the static director orientation. When the electric field is applied to the nematic, the director moves from being parallel to the magnetic field to being at an angle to it (the turn-on process) because Delta epsilon and Delta chi are both positive for 5CB. After the electric field is switched off, the director relaxes back to being parallel to the magnetic field (the turn-off process). Deuterium NMR spectra were recorded during the turn-on and the turn-off alignment processes as a function of time. Analysis of these results for the static and dynamic experiments, based on the predictions of continuum theory, provides the physical properties of the nematic.

Full text not available from this repository.

More information

Published date: 2005
Keywords: induced director dynamics, magnetic-resonance spectroscopy, liquid-crystal, orientational order, phase, reorientation, polymer, 4-octyl-4'-cyanobiphenyl, behavior

Identifiers

Local EPrints ID: 44495
URI: http://eprints.soton.ac.uk/id/eprint/44495
ISSN: 1366-5855
PURE UUID: a993f1fc-2c85-4420-a89b-ac25bab6011d

Catalogue record

Date deposited: 02 Mar 2007
Last modified: 13 Mar 2019 21:07

Export record

Altmetrics

Contributors

Author: G.R. Luckhurst
Author: A. Sugimura
Author: B.A. Timimi
Author: H. Zimmermann

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×