Size dependence of solute diffusivity and Stokes-Einstein relationship: effect of van der Waals interaction

• Main Authors: Sharma, Manju, Yashonath, Subramanian
• Other Authors: Solid State and Structural Chemistry Unit, India Institute of Science
• Format: Article
• Language: English
• Published: Universitätsbibliothek Leipzig 2016
• Subjects: Diffusion; Transport; diffusion; transport; ddc:530
• Online Access: http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-193071; http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-193071; http://www.qucosa.de/fileadmin/data/qucosa/documents/19307/diff_fund_7%282007%2911.pdf

Size dependence of solute diffusivity has been investigated using molecular dynamics simulations for a range of solute radii in a binary mixture consisting of solute and solvent species. We demonstrate that the Stokes-Einstein relationship between self diffusivity and solute radius breaks down over a range of solute-solvent size ratios. This is a result of the previously known Levitation Effect. Three distinct regimes can be seen depending on the solute-solvent size ratio. Several properties have been computed to understand the nature of solute motion in the three regimes.