Influence of double-layer polarization and chemiosmosis on the diffusiophoresis of a non-spherical polyelectrolyte
Journal
Journal of Colloid and Interface Science
Journal Volume
446
Pages
272-281
Date Issued
2015
Author(s)
Abstract
The diffusiophoresis of a non-spherical polyelectrolyte (PE) is modeled theoretically by considering an ellipsoidal PE of fixed volume and varying aspect ratio, capable of simulating porous entities such as DNAs, proteins, and synthetic polymeric particles. A continuum model comprising coupled Poisson-Nernst-Planck equations and Stokes equations is adopted. Parameters including the physicochemical properties of a PE, the degree of deformation, and the bulk ionic concentration are examined in detail for their influence on the diffusiophoretic behavior of the PE. We show that the effects of double-layer polarization, polarization of the condensed counterions inside a PE, and the chemiosmotic retardation flow inside it yield complicated diffusiophoretic behavior. In particular, the mobility of an elliptic PE can differ both quantitatively and qualitatively from that of a spherical PE. This phenomenon, which has not been reported previously, provides valuable information for both experimental data interpretation and device design. ? 2015 Elsevier Inc.
Subjects
Chemiosmosis
Diffusiophoresis
Double-layer polarization
Non-spherical polyelectrolyte
Type
journal article