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Long-Ranged Attractive Forces Induced by Adsorbed Dendrimers: Direct Force Measurements and Computer Simulations

Popa, Ionel; Trulsson, Martin LU ; Papastavrou, Georg; Borkovec, Michal and Jönsson, Bo LU (2009) In Langmuir 25(21). p.12435-12438
Abstract
Interaction forces between charged interfaces in the presence of oppositely charged dendrimers are studied by experiment and simulation. The experiments involve direct force measurements with all atomic force microscope (AFM) between two negatively charged colloidal particles in the presence of adsorbed, positively charged globular dendrimers. The simulations are carried out by treating the macroions explicitly, while the small salt ions are treated implicitly through the Debye-Huckel approximation. The system undergoes overcharging, and at the isoelectric point long-ranged attractive electrostatic forces are present. The range of the attraction is on the order of half the Debye length at high salt concentration, but it becomes smaller at... (More)
Interaction forces between charged interfaces in the presence of oppositely charged dendrimers are studied by experiment and simulation. The experiments involve direct force measurements with all atomic force microscope (AFM) between two negatively charged colloidal particles in the presence of adsorbed, positively charged globular dendrimers. The simulations are carried out by treating the macroions explicitly, while the small salt ions are treated implicitly through the Debye-Huckel approximation. The system undergoes overcharging, and at the isoelectric point long-ranged attractive electrostatic forces are present. The range of the attraction is on the order of half the Debye length at high salt concentration, but it becomes smaller at low salt concentration. Away from the isoelectric point, repulsive electrostatic forces are observed due to diffuse layer overlap. A semiquantitative agreement between experiment and Simulation is obtained, despite the fact that the simple theoretical model does not involve any adjustable parameters. This study provides for the first time detailed comparison between experimental and simulation data of interaction forces between colloidal particles in the presence of multivalent macroions and monovalent salt ions. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
25
issue
21
pages
12435 - 12438
publisher
The American Chemical Society
external identifiers
  • wos:000271106600008
  • scopus:70449358307
ISSN
0743-7463
DOI
10.1021/la902617x
language
English
LU publication?
yes
id
14fbf30f-c15d-4621-bc4c-a2538364906c (old id 1505348)
date added to LUP
2009-11-24 11:50:42
date last changed
2017-10-01 03:46:47
@article{14fbf30f-c15d-4621-bc4c-a2538364906c,
  abstract     = {Interaction forces between charged interfaces in the presence of oppositely charged dendrimers are studied by experiment and simulation. The experiments involve direct force measurements with all atomic force microscope (AFM) between two negatively charged colloidal particles in the presence of adsorbed, positively charged globular dendrimers. The simulations are carried out by treating the macroions explicitly, while the small salt ions are treated implicitly through the Debye-Huckel approximation. The system undergoes overcharging, and at the isoelectric point long-ranged attractive electrostatic forces are present. The range of the attraction is on the order of half the Debye length at high salt concentration, but it becomes smaller at low salt concentration. Away from the isoelectric point, repulsive electrostatic forces are observed due to diffuse layer overlap. A semiquantitative agreement between experiment and Simulation is obtained, despite the fact that the simple theoretical model does not involve any adjustable parameters. This study provides for the first time detailed comparison between experimental and simulation data of interaction forces between colloidal particles in the presence of multivalent macroions and monovalent salt ions.},
  author       = {Popa, Ionel and Trulsson, Martin and Papastavrou, Georg and Borkovec, Michal and Jönsson, Bo},
  issn         = {0743-7463},
  language     = {eng},
  number       = {21},
  pages        = {12435--12438},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Long-Ranged Attractive Forces Induced by Adsorbed Dendrimers: Direct Force Measurements and Computer Simulations},
  url          = {http://dx.doi.org/10.1021/la902617x},
  volume       = {25},
  year         = {2009},
}