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Block polyelectrolytes and colloidal stability.

Turesson, Martin LU ; Åkesson, Torbjörn LU and Forsman, Jan LU (2008) In Journal of Colloid and Interface Science 329(1). p.67-72
Abstract
We simulate interactions between charged flat surfaces in the presence of block polymers, where the end blocks carry a charge opposite to the surfaces. Using a recently developed simulation technique, we allow full equilibrium, i.e. the chemical potential of the polyelectrolyte is retained as the separation is changed. In general, the block polyions will adsorb strongly enough to overcharge the surfaces. This results in a double layer repulsion at large separation, with a concomitant free energy barrier. At short separations, the surfaces are pulled together by bridging forces. We make some efforts to theoretically design the polymers to be efficient flocculants, i.e. minimize the free energy barrier and still allow for a long-ranged... (More)
We simulate interactions between charged flat surfaces in the presence of block polymers, where the end blocks carry a charge opposite to the surfaces. Using a recently developed simulation technique, we allow full equilibrium, i.e. the chemical potential of the polyelectrolyte is retained as the separation is changed. In general, the block polyions will adsorb strongly enough to overcharge the surfaces. This results in a double layer repulsion at large separation, with a concomitant free energy barrier. At short separations, the surfaces are pulled together by bridging forces. We make some efforts to theoretically design the polymers to be efficient flocculants, i.e. minimize the free energy barrier and still allow for a long-ranged bridging attraction. Here, we also take into account the possibility of nonequilibrium circumstances, which may be relevant in practice. Our results suggest that short chains, with small charged end blocks and a (relatively speaking) long neutral mid block, are likely to promote rapid flocculation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Colloid and Interface Science
volume
329
issue
1
pages
67 - 72
publisher
Elsevier
external identifiers
  • pmid:18929372
  • scopus:55349130287
ISSN
1095-7103
DOI
10.1016/j.jcis.2008.09.049
language
English
LU publication?
yes
id
43bb7aa2-4ddf-42ea-a552-1a043e4a8ce7 (old id 1262127)
date added to LUP
2008-11-25 18:01:50
date last changed
2017-01-01 05:15:48
@article{43bb7aa2-4ddf-42ea-a552-1a043e4a8ce7,
  abstract     = {We simulate interactions between charged flat surfaces in the presence of block polymers, where the end blocks carry a charge opposite to the surfaces. Using a recently developed simulation technique, we allow full equilibrium, i.e. the chemical potential of the polyelectrolyte is retained as the separation is changed. In general, the block polyions will adsorb strongly enough to overcharge the surfaces. This results in a double layer repulsion at large separation, with a concomitant free energy barrier. At short separations, the surfaces are pulled together by bridging forces. We make some efforts to theoretically design the polymers to be efficient flocculants, i.e. minimize the free energy barrier and still allow for a long-ranged bridging attraction. Here, we also take into account the possibility of nonequilibrium circumstances, which may be relevant in practice. Our results suggest that short chains, with small charged end blocks and a (relatively speaking) long neutral mid block, are likely to promote rapid flocculation.},
  author       = {Turesson, Martin and Åkesson, Torbjörn and Forsman, Jan},
  issn         = {1095-7103},
  language     = {eng},
  number       = {1},
  pages        = {67--72},
  publisher    = {Elsevier},
  series       = {Journal of Colloid and Interface Science},
  title        = {Block polyelectrolytes and colloidal stability.},
  url          = {http://dx.doi.org/10.1016/j.jcis.2008.09.049},
  volume       = {329},
  year         = {2008},
}