Please use this identifier to cite or link to this item: http://dx.doi.org/10.14279/depositonce-9609
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Main Title: A novel model for smectic liquid crystals: Elastic anisotropy and response to a steady-state flow
Author(s): Püschel-Schlotthauer, Sergej
Meiwes Turrión, Victor
Stieger, Tillmann
Grotjahn, Robin
Hall, Carol K.
Mazza, Marco G.
Schoen, Martin
Type: Article
Language Code: en
Abstract: By means of a combination of equilibrium Monte Carlo and molecular dynamics simulations and nonequilibrium molecular dynamics we investigate the ordered, uniaxial phases (i.e., nematic and smectic A) of a model liquid crystal. We characterize equilibrium behavior through their diffusive behavior and elastic properties. As one approaches the equilibrium isotropic-nematic phase transition, diffusion becomes anisotropic in that self-diffusion D⊥ in the direction orthogonal to a molecule’s long axis is more hindered than self-diffusion D∥ in the direction parallel to that axis. Close to nematic-smectic A phase transition the opposite is true, D∥ < D⊥. The Frank elastic constants K1, K2, and K3 for the respective splay, twist, and bend deformations of the director field n̂ are no longer equal and exhibit a temperature dependence observed experimentally for cyanobiphenyls. Under nonequilibrium conditions, a pressure gradient applied to the smectic A phase generates Poiseuille-like or plug flow depending on whether the convective velocity is parallel or orthogonal to the plane of smectic layers. We find that in Poiseuille-like flow the viscosity of the smectic A phase is higher than in plug flow. This can be rationalized via the velocity-field component in the direction of the flow. In a sufficiently strong flow these smectic layers are not destroyed but significantly bent.
URI: https://depositonce.tu-berlin.de/handle/11303/10712
http://dx.doi.org/10.14279/depositonce-9609
Issue Date: 25-Oct-2016
Date Available: 6-Feb-2020
DDC Class: 540 Chemie und zugeordnete Wissenschaften
530 Physik
Subject(s): bending
convection
elastic constants
liquid crystal phase transformations
molecular dynamics method
Monte Carlo methods
nematic liquid crystals
organic compounds
self-diffusion
smectic liquid crystals
viscosity
Sponsor/Funder: DFG, 65143814, GRK 1524: Self-Assembled Soft-Matter Nanostructures at Interfaces
License: http://rightsstatements.org/vocab/InC/1.0/
Journal Title: The Journal of Chemical Physics
Publisher: American Institute of Physics (AIP)
Publisher Place: Melville, NY
Volume: 145
Issue: 16
Article Number: 164903
Publisher DOI: 10.1063/1.4965711
EISSN: 1089-7690
ISSN: 0021-9606
Notes: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Chem. Phys. 145, 164903 (2016) and may be found at https://doi.org/10.1063/1.4965711.
Appears in Collections:FG Theoretische Chemie » Publications

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