Polarization of acetonitrile under thermal fields via non-equilibrium molecular dynamics simulations.
File(s)
Accepted version
Author(s)
Gittus, Oliver R
Albella, Pablo
Bresme, Fernando
Type
Journal Article
Abstract
We show that thermal gradients polarize liquid and supercritical acetonitrile. The polarization results in a stationary electrostatic potential that builds up between hot and cold regions. The strength of the field increases with the static dielectric constant or with decreasing temperature. At near standard conditions, the thermal polarization coefficient is ∼-0.6 mV/K, making it possible to induce significant electrostatic fields, ∼103 V/m, with thermal gradients ∼1 K/μm. At supercritical conditions, ∼600 K and 0.249 g/cm3 (the critical isochore), the electrostatic field is of the same order, despite the low dielectric constant of the fluid. In this case, the electrostatic field is determined by the enhanced rotational diffusion of the molecules and stronger cross-coupling between heat and polarization fluxes. We show that the coupling between the heat and polarization fluxes influences the thermal conductivity of acetonitrile, which becomes a worse heat conductor. For the thermodynamic states investigated in this work, the thermal polarization effect leads to a ∼2%-5% reduction in thermal conductivity.
Date Issued
2020-11-24
Date Acceptance
2020-10-28
Citation
Journal of Chemical Physics, 2020, 153 (20), pp.204503-204503
ISSN
0021-9606
Publisher
American Institute of Physics
Start Page
204503
End Page
204503
Journal / Book Title
Journal of Chemical Physics
Volume
153
Issue
20
Copyright Statement
© 2020 Author(s).
This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Chem. Phys. 153, 204503 (2020); https://doi.org/10.1063/5.0025148
This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Chem. Phys. 153, 204503 (2020); https://doi.org/10.1063/5.0025148
Sponsor
The Leverhulme Trust
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/33261474
Grant Number
RPG-2018-384
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
CONDUCTIVITIES
TEMPERATURE
MIXTURES
LIQUIDS
WATER
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Chemical Physics
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2020-11-24