Source:http://linkedlifedata.com/resource/pubmed/id/18543988
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
26
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| pubmed:dateCreated |
2008-6-27
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| pubmed:abstractText |
We investigated the effect of counterion valence on the structure and swelling behavior of polyelectrolyte brushes using a nonlocal density functional theory that accounts for the excluded-volume effects of all ionic species and intrachain and electrostatic correlations. It was shown that charge correlation in the presence of multivalent counterions results in collapse of a polyelectrolyte brush at an intermediate polyion grafting density. At high grafting density, the brush reswells in a way similar to that in a monovalent ionic solution. In the presence of multivalent counterions, the nonmonotonic swelling of a polyelectrolyte brush in response to the increase of the grafting density can be attributed to a competition of the counterion-mediated electrostatic attraction between polyions with the excluded-volume effect of all ionic species. While a polyelectrolyte brush exhibits an "osmotic brush" regime at low salt concentration and a "salted brush" regime at high salt concentration regardless of the counterion valence, we found a smoother transition as the valence of the counterions increases. As observed in recent experiments, a quasi-power-law dependence of the brush thickness on the concentration ratio can be identified when the monovalent counterions are replaced with trivalent counterions at a fixed ionic strength.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Jul
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| pubmed:issn |
1520-6106
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
3
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| pubmed:volume |
112
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
7713-20
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| pubmed:year |
2008
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| pubmed:articleTitle |
Ionic effects in collapse of polyelectrolyte brushes.
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| pubmed:affiliation |
Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0444, USA.
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| pubmed:publicationType |
Journal Article
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