Diffusion of small solute particles in viscous liquids: cage diffusion, a result of decoupling of solute-solvent dynamics, leads to amplification of solute diffusion

TitleDiffusion of small solute particles in viscous liquids: cage diffusion, a result of decoupling of solute-solvent dynamics, leads to amplification of solute diffusion
Publication TypeJournal Article
Year of Publication2015
AuthorsAcharya, S, Nandi, MK, Mandal, A, Sarkar, S, Bhattacharyya, SMaitra
JournalJournal of Physical Chemistry B
Volume119
Issue34
Pagination11169-11175
Date PublishedAUG
ISSN1520-6106
Abstract

We study the diffusion of small solute particles through solvent by keeping the solute solvent interaction repulsive and varying the solvent properties. The study involves computer simulations, development of a new model to describe diffusion of small solutes in a solvent, and also mode coupling theory (MCT) calculations. In a viscous solvent, a small solute diffuses via coupling to the solvent hydrodynamic modes and also through the transient cages formed by the solvent. The model developed can estimate the independent contributions from these two different channels of diffusion. Although the solute diffusion in all the systems shows an amplification, the degree of it increases with solvent viscosity. The model correctly predicts that when the solvent viscosity is high, the solute primarily diffuses by exploiting the solvent cages. In such a scenario the MCT diffusion performed for a static solvent provides a correct estimation of the cage diffusion.

DOI10.1021/acs.jpcb.5b03034
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

3.187

Divison category: 
Polymer Science & Engineering