Advanced

Adsorption versus aggregation. Particles and surface of the same material

Linse, Per LU and Wennerström, Håkan LU (2012) In Soft Matter 8(8). p.2486-2493
Abstract
A model for the adsorption of colloidal particles on a planar surface is analyzed by using a thermodynamic chemical equilibrium model and Monte Carlo simulations. Central to this investigation are that (i) particles and surface are considered to be of the same material and (ii) the particle-surface and particle-particle interactions are related using the Derjaguin approximation using a surface-surface square-well potential as a basis. Thereby, all interactions within the system are characterized by the same parameters, and hence the difference between particle adsorption on the surface and particle aggregation in bulk is solely due to geometrical effects. Equilibrium constants for the different binary associations are calculated from the... (More)
A model for the adsorption of colloidal particles on a planar surface is analyzed by using a thermodynamic chemical equilibrium model and Monte Carlo simulations. Central to this investigation are that (i) particles and surface are considered to be of the same material and (ii) the particle-surface and particle-particle interactions are related using the Derjaguin approximation using a surface-surface square-well potential as a basis. Thereby, all interactions within the system are characterized by the same parameters, and hence the difference between particle adsorption on the surface and particle aggregation in bulk is solely due to geometrical effects. Equilibrium constants for the different binary associations are calculated from the interaction potentials enabling a direct comparison between predictions based on a chemical equilibrium model and on computer simulations with no adjustable parameters. As the interaction gradually is made more attractive for a given particle concentration, we find the following sequence of events: (A) a weak particle adsorption onto the surface, (B) particle association on the surface forming a denser single adsorbed layer, (C) formation of a second adsorbed layer on the surface, (D) multiple adsorbed layers on the surface, and (E) bulk phase separation. There is a semi-quantitative agreement between the predictions of the equilibrium model and the results of the simulations. The equilibrium model calculations facilitate a conceptual understanding of the competition between association on a surface and in bulk. Our study is relevant both for understanding processes where colloidal particle adsorption is used to modify surface properties and also for the understanding of heterogeneous versus homogeneous nucleation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
8
issue
8
pages
2486 - 2493
publisher
Royal Society of Chemistry
external identifiers
  • wos:000299741200019
  • scopus:84857252295
ISSN
1744-6848
DOI
10.1039/c2sm07000f
language
English
LU publication?
yes
id
9e741029-7e48-4a75-aa1f-a1d8e6e29d08 (old id 2425502)
date added to LUP
2012-03-28 09:53:05
date last changed
2017-07-30 04:04:37
@article{9e741029-7e48-4a75-aa1f-a1d8e6e29d08,
  abstract     = {A model for the adsorption of colloidal particles on a planar surface is analyzed by using a thermodynamic chemical equilibrium model and Monte Carlo simulations. Central to this investigation are that (i) particles and surface are considered to be of the same material and (ii) the particle-surface and particle-particle interactions are related using the Derjaguin approximation using a surface-surface square-well potential as a basis. Thereby, all interactions within the system are characterized by the same parameters, and hence the difference between particle adsorption on the surface and particle aggregation in bulk is solely due to geometrical effects. Equilibrium constants for the different binary associations are calculated from the interaction potentials enabling a direct comparison between predictions based on a chemical equilibrium model and on computer simulations with no adjustable parameters. As the interaction gradually is made more attractive for a given particle concentration, we find the following sequence of events: (A) a weak particle adsorption onto the surface, (B) particle association on the surface forming a denser single adsorbed layer, (C) formation of a second adsorbed layer on the surface, (D) multiple adsorbed layers on the surface, and (E) bulk phase separation. There is a semi-quantitative agreement between the predictions of the equilibrium model and the results of the simulations. The equilibrium model calculations facilitate a conceptual understanding of the competition between association on a surface and in bulk. Our study is relevant both for understanding processes where colloidal particle adsorption is used to modify surface properties and also for the understanding of heterogeneous versus homogeneous nucleation.},
  author       = {Linse, Per and Wennerström, Håkan},
  issn         = {1744-6848},
  language     = {eng},
  number       = {8},
  pages        = {2486--2493},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Adsorption versus aggregation. Particles and surface of the same material},
  url          = {http://dx.doi.org/10.1039/c2sm07000f},
  volume       = {8},
  year         = {2012},
}