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Sterically stabilized colloids with tunable repulsions

van Gruijthuijsen, Kitty; Obiols-Rabasa, Marc LU ; Heinen, Marco; Nägele, Gerhard and Stradner, Anna LU (2013) In Langmuir 29(36). p.11199-11207
Abstract
When studying tunable electrostatic repulsions in aqueous suspensions of charged colloids, irreversible colloid aggregation or gelation may occur at high salt concentrations. For many commonly used synthetic colloids, such as polystyrene and silica particles, the reason for coagulation is the presence of unbalanced, strongly attractive, and short-ranged van der Waals (VDW) forces. Here, we present an aqueous polystyrene model colloid that is sterically stabilized against VDW attractions. We show that the synthesis procedure, based on a neutral initiator couple and a nonionic surfactant, introduces surface charges that can be further increased by the addition of charged comonomer methacrylic acid. Thus, the interactions between the... (More)
When studying tunable electrostatic repulsions in aqueous suspensions of charged colloids, irreversible colloid aggregation or gelation may occur at high salt concentrations. For many commonly used synthetic colloids, such as polystyrene and silica particles, the reason for coagulation is the presence of unbalanced, strongly attractive, and short-ranged van der Waals (VDW) forces. Here, we present an aqueous polystyrene model colloid that is sterically stabilized against VDW attractions. We show that the synthesis procedure, based on a neutral initiator couple and a nonionic surfactant, introduces surface charges that can be further increased by the addition of charged comonomer methacrylic acid. Thus, the interactions between the polystyrene spheres can be conveniently tuned from hard-sphere-like to charge-stabilized with long-ranged electrostatic repulsions described by a Yukawa-type pair potential. The particle size, grafting density, core-shell structure, and surface charge are characterized by light and neutron scattering. Using X-ray and neutron scattering in combination with an accurate analytic integral equation scheme for the colloidal static structure factor, we deduce effective particle charges for colloid volume fractions ≥0.1 and salt concentrations in the range of 1.5 to 50 mM. (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
Langmuir
volume
29
issue
36
pages
11199 - 11207
publisher
The American Chemical Society (ACS)
external identifiers
  • wos:000330079900001
  • scopus:84884181006
ISSN
0743-7463
DOI
10.1021/la402104q
language
English
LU publication?
yes
id
c2b3d660-9a4c-45ab-a662-2454698741f9 (old id 4239502)
date added to LUP
2014-02-10 11:19:31
date last changed
2019-10-23 01:24:54
@article{c2b3d660-9a4c-45ab-a662-2454698741f9,
  abstract     = {When studying tunable electrostatic repulsions in aqueous suspensions of charged colloids, irreversible colloid aggregation or gelation may occur at high salt concentrations. For many commonly used synthetic colloids, such as polystyrene and silica particles, the reason for coagulation is the presence of unbalanced, strongly attractive, and short-ranged van der Waals (VDW) forces. Here, we present an aqueous polystyrene model colloid that is sterically stabilized against VDW attractions. We show that the synthesis procedure, based on a neutral initiator couple and a nonionic surfactant, introduces surface charges that can be further increased by the addition of charged comonomer methacrylic acid. Thus, the interactions between the polystyrene spheres can be conveniently tuned from hard-sphere-like to charge-stabilized with long-ranged electrostatic repulsions described by a Yukawa-type pair potential. The particle size, grafting density, core-shell structure, and surface charge are characterized by light and neutron scattering. Using X-ray and neutron scattering in combination with an accurate analytic integral equation scheme for the colloidal static structure factor, we deduce effective particle charges for colloid volume fractions ≥0.1 and salt concentrations in the range of 1.5 to 50 mM.},
  author       = {van Gruijthuijsen, Kitty and Obiols-Rabasa, Marc and Heinen, Marco and Nägele, Gerhard and Stradner, Anna},
  issn         = {0743-7463},
  language     = {eng},
  number       = {36},
  pages        = {11199--11207},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Langmuir},
  title        = {Sterically stabilized colloids with tunable repulsions},
  url          = {http://dx.doi.org/10.1021/la402104q},
  volume       = {29},
  year         = {2013},
}