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Diffusion in evaporating solutions

Kabalnov, A. and Wennerström, Håkan LU (2009) In Soft Matter 5(23). p.4712-4718
Abstract
We present an analysis of the colloidal dynamics of particles in a mixture of two solvents subjected to evaporation. For simplicity, only one out of the two solvents is considered to be volatile. The evaporation generates a distribution of the solvent concentration in the system. As the particles selectively interact with the solvents, their migration becomes affected by a "chemotaxis" force, caused by the gradient in the solvation energy along the diffusion path. The net particle flux is the result of the interplay between the migration under the action of the chemotaxis and the bulk convection flow caused by the evaporation. The most unusual features of the particle migration occur when the particles have an affinity to the evaporating... (More)
We present an analysis of the colloidal dynamics of particles in a mixture of two solvents subjected to evaporation. For simplicity, only one out of the two solvents is considered to be volatile. The evaporation generates a distribution of the solvent concentration in the system. As the particles selectively interact with the solvents, their migration becomes affected by a "chemotaxis" force, caused by the gradient in the solvation energy along the diffusion path. The net particle flux is the result of the interplay between the migration under the action of the chemotaxis and the bulk convection flow caused by the evaporation. The most unusual features of the particle migration occur when the particles have an affinity to the evaporating solvent. In this case, the particles may diffuse against the concentration gradient and form bands with increased particle concentration, i.e., undergo focusing. The resulting particle concentration patterns are strongly dependent on the geometry of the container in which the evaporation occurs. This model has important practical applications. It provides a framework for understanding and controlling the skin formation at the surface of evaporating colloidal suspensions, an effect that is briefly illustrated experimentally on the example of ink-jet printing. On a thermodynamic level, the model is also applicable to cases, in which the third component is molecularly dispersed, although a smaller magnitude of the effects is predicted. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
5
issue
23
pages
4712 - 4718
publisher
Royal Society of Chemistry
external identifiers
  • wos:000271907900015
  • scopus:70450265335
ISSN
1744-6848
DOI
10.1039/b912648a
language
English
LU publication?
yes
id
6680e18f-ae65-4537-98bf-02b9a4a074d2 (old id 1517932)
date added to LUP
2010-01-13 11:50:39
date last changed
2017-06-04 04:09:33
@article{6680e18f-ae65-4537-98bf-02b9a4a074d2,
  abstract     = {We present an analysis of the colloidal dynamics of particles in a mixture of two solvents subjected to evaporation. For simplicity, only one out of the two solvents is considered to be volatile. The evaporation generates a distribution of the solvent concentration in the system. As the particles selectively interact with the solvents, their migration becomes affected by a "chemotaxis" force, caused by the gradient in the solvation energy along the diffusion path. The net particle flux is the result of the interplay between the migration under the action of the chemotaxis and the bulk convection flow caused by the evaporation. The most unusual features of the particle migration occur when the particles have an affinity to the evaporating solvent. In this case, the particles may diffuse against the concentration gradient and form bands with increased particle concentration, i.e., undergo focusing. The resulting particle concentration patterns are strongly dependent on the geometry of the container in which the evaporation occurs. This model has important practical applications. It provides a framework for understanding and controlling the skin formation at the surface of evaporating colloidal suspensions, an effect that is briefly illustrated experimentally on the example of ink-jet printing. On a thermodynamic level, the model is also applicable to cases, in which the third component is molecularly dispersed, although a smaller magnitude of the effects is predicted.},
  author       = {Kabalnov, A. and Wennerström, Håkan},
  issn         = {1744-6848},
  language     = {eng},
  number       = {23},
  pages        = {4712--4718},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Diffusion in evaporating solutions},
  url          = {http://dx.doi.org/10.1039/b912648a},
  volume       = {5},
  year         = {2009},
}