The Library
Elastic constants and dynamics in nematic liquid crystals
Tools
Humpert, Anja and Allen, M. P. (2015) Elastic constants and dynamics in nematic liquid crystals. Molecular Physics, 113 (17-18). pp. 2680-2692. doi:10.1080/00268976.2015.1067730 ISSN 0026-8976.
|
PDF
WRAP-elastic-constants-dynamics-nematic-crystals-Humpert-2015.pdf - Accepted Version - Requires a PDF viewer. Download (2306Kb) | Preview |
Official URL: https://doi.org/10.1080/00268976.2015.1067730
Abstract
In this paper we present molecular dynamics calculations of the Frank elastic constants, and associated time correlation functions, in nematic liquid crystals. We study two variants of the Gay-Berne potential, and use system sizes of half a million molecules, significantly larger than in previous studies of elastic behaviour. Equilibrium orientational fluctuations in reciprocal (k-) space were calculated, to determine the elastic constants by fitting at low k; our results indicate that small system size may be a source of inaccuracy in previous work. Furthermore the dynamics of the Gay-Berne nematic were studied by calculating time correlation functions of components of the order tensor, together with associated components of the velocity field, for a set of wave vectors k. Confirming our earlier work, we found exponential decay for splay and twist correlations, and oscillatory exponential decay for the bend correlation. In the present work, we confirm similar behaviour for the corresponding velocity components. In all cases the decay rates, and oscillation frequencies, were found to be accurately proportional to k-squared for small k, as predicted by the equations of nematodynamics. However, the observation of oscillatory bend fluctuations, and corresponding oscillatory shear flow decay, is in contradiction to the usual assumptions appearing in the literature, and in standard texts. We discuss the advantages and drawbacks of using large systems in these calculations.
Item Type: | Journal Article | ||||||
---|---|---|---|---|---|---|---|
Subjects: | Q Science > QC Physics | ||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | ||||||
Library of Congress Subject Headings (LCSH): | Nematic liquid crystals -- molecular aspects -- Mathematical models, Hydrodynamics, Molecular dynamics | ||||||
Journal or Publication Title: | Molecular Physics | ||||||
Publisher: | Taylor & Francis Ltd. | ||||||
ISSN: | 0026-8976 | ||||||
Official Date: | 24 July 2015 | ||||||
Dates: |
|
||||||
Volume: | 113 | ||||||
Number: | 17-18 | ||||||
Page Range: | pp. 2680-2692 | ||||||
DOI: | 10.1080/00268976.2015.1067730 | ||||||
Status: | Peer Reviewed | ||||||
Publication Status: | Published | ||||||
Access rights to Published version: | Restricted or Subscription Access | ||||||
Date of first compliant deposit: | 28 July 2016 | ||||||
Date of first compliant Open Access: | 10 October 2018 | ||||||
RIOXX Funder/Project Grant: |
|
||||||
Related URLs: |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year