2024-03-29T13:19:09Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:02004223
2023-07-07T00:26:24Z
320:321:322
Comparison between longitudinal viscoelastic relaxation and sound dispersion of molecular liquids on the molecular scale
Yamaguchi, Tsuyoshi
open access
Copyright 2022 Author(s). Published under an exclusive license by AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing.The following article appeared in (J. Chem. Phys. 156, 244505 (2022)) and may be found at (https://doi.org/10.1063/5.0098098).
Molecular dynamics simulation on some molecular liquids was performed to study sound dispersion on the molecular scale. The sound velocity was determined from the intermediate scattering function, and the relation between the longitudinal modulus and frequency was compared with the frequency-dependent longitudinal modulus in the q = 0 limit evaluated by the Kubo–Green theory. The sound dispersion of a monoatomic liquid up to qσ ≅ 2 was almost quantitatively explained by the viscoelasticity in the q = 0 limit when the wavenumber dependence of the heat capacity ratio was taken into account. The situation was similar for a polyatomic molecular liquid for which the intramolecular degrees of freedom were fixed. For a polyatomic liquid with intramolecular degrees of freedom, the sound dispersion on the molecular scale was connected to the high-frequency limit of the ultrasonic relaxation mode assigned to the vibrational energy relaxation. After subtracting the contribution of the vibrational energy relaxation, both the longitudinal viscoelasticity and the sound dispersion depended little on the presence of intramolecular degrees of freedom.
AIP Publishing
2023-06-29
2022-06-29
eng
journal article
VoR
http://hdl.handle.net/2237/0002004223
https://nagoya.repo.nii.ac.jp/records/2004223
https://doi.org/10.1063/5.0098098
0021-9606
The Journal of Chemical Physics
156
24
244505
https://nagoya.repo.nii.ac.jp/record/2004223/files/5_0098098.pdf
application/pdf
5.2 MB
2023-06-29