Phase diagram of a rigid rod system with attractive end groups
File(s)
Author(s)
Crane, Andrew
Muller, Erich
Type
Journal Article
Abstract
We present a molecular dynamics study into the thermotropic liquid crystalline phase behaviour of a coarse-grained model of a rigid bolaamphiphilic molecule. The model consists of 11 spherical beads held in a fixed linear arrangement, where the two opposing terminal beads are self-attracting, mimicking hydrophilic segments and the remaining internal beads, as well as cross-bead interactions, are softly repulsive, mimicking hydrophobic organic segments. The effect of the model’s end bead self-attraction strength on liquid crystalline phase behaviour is studied. Coexistence points between the smectic A, nematic and isotropic phases exhibited by the model are determined following a thermodynamic integration pathway, using equations of state constructed by multiple histogram reweighting of simulation data. Variants of Gibbs–Duhem integration are used to trace pressure–temperature coexistence curves. Under isobaric conditions, the effect of increasing the end-group self-attraction on the nematic–isotropic coexistence temperature is relatively small; however, the nematic phase stability is reduced at the expense of a significant increase in the smectic A–nematic coexistence temperature. Lower temperature simulations show the approximate smectic A–crystalline transition temperature to be only weakly dependent on the strength of the end-group self-attraction.
Date Issued
2024-11
Date Acceptance
2024-03-03
Citation
Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, 2024, 122 (21-22)
ISSN
0026-8976
Publisher
Taylor and Francis Group
Journal / Book Title
Molecular Physics: An International Journal at the Interface Between Chemistry and Physics
Volume
122
Issue
21-22
Copyright Statement
© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License(http://creativecommons.org/licenses/by-nc-nd/4.0/),
which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any
way. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License(http://creativecommons.org/licenses/by-nc-nd/4.0/),
which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any
way. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.
Identifier
https://www.tandfonline.com/doi/full/10.1080/00268976.2024.2327528?src=
Publication Status
Published
Article Number
e2327528
Date Publish Online
2024-03-20