Decoupling between Solvent Viscosity and Diffusion of a Small Solute Induced by Self-Motion

• Yamaguchi, Tsuyoshi

Abstract

The self-diffusion of a monatomic solute in liquid 1-octanol and n-tetradecane was investigated by means of a molecular dynamics simulation. The diffusion coefficient of a solute as small as argon is much greater than that obtained from the hydrodynamic-based Stokes–Einstein (SE) relation, as was reported experimentally. A relaxation of the memory function of a freely diffusing solute is much faster than that of the autocorrelation function of a shear stress. However, the SE behavior is recovered when the solute is spatially fixed, and the diffusion coefficient is calculated from the force–force autocorrelation function. A relaxation of the autocorrelation function of the force also follows that of shear stress. The fast diffusion of a small solute is thus ascribed to the decoupling between the structural relaxation of solvent and the solute diffusion induced by the self-motion of the solute.

Journal

• The Journal of Physical Chemistry Letters

  The Journal of Physical Chemistry Letters 12 (32), 7696-7700, 2021-08-19

  ACS Publications

Keywords

• General Materials Science
• Physical and Theoretical Chemistry

Details

• CRID: 1050572590044625792
• NII Article ID: 120007190687
• DOI: 10.1021/acs.jpclett.1c02219
• ISSN: 19487185
• HANDLE: 2237/0002002049
• Web Site: https://nagoya.repo.nii.ac.jp/records/2002049
• Web Site: https://pubs.acs.org/doi/pdf/10.1021/acs.jpclett.1c02219
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN