Diffusiophoresis in one-dimensional solute gradients.

TitleDiffusiophoresis in one-dimensional solute gradients.
Publication TypeJournal Article
Year of Publication2017
AuthorsAult, JT, Warren, PB, Shin, S, Stone, HA
JournalSoft Matter
Volume13
Issue47
Pagination9015-9023
Date Published2017 Dec 06
ISSN1744-6848
Abstract

The diffusiophoretic motion of suspended colloidal particles under one-dimensional solute gradients is solved using numerical and analytical techniques. Similarity solutions are developed for the injection and withdrawal dynamics of particles into semi-infinite pores. Furthermore, a method of characteristics formulation of the diffusion-free particle transport model is presented and integrated to realize particle trajectories. Analytical solutions are presented for the limit of small particle diffusiophoretic mobility Γp relative to the solute diffusivity Ds for particle motions in both semi-infinite and finite domains. Results confirm the build up of local maxima and minima in the propagating particle front dynamics. The method of characteristics is shown to successfully predict particle motions and the position of the particle front, although it fails to accurately predict suspended particle concentrations in the vicinity of sharp gradients, such as at the particle front peak seen in some injection cases, where particle diffusion inevitably plays an important role. Results inform the design of applications in which the use of applied solute gradients can greatly enhance particle injection into and withdrawal from pores.

DOI10.1039/c7sm01588g
Alternate JournalSoft Matter
PubMed ID29165484