The Influence of Polyelectrolytes on the Stability of Colloids
(1998)- Abstract
- The interaction between two colloids with grafted polyelectrolytes in aqueous solution is studied within the primitive model by Monte Carlo simulations. For neutral colloids with grafted polyelectrolytes and in absence of salt the interaction is strongly repulsive in absence of salt. The interaction depends on the extension of the polyelectrolytes from the surfaces and the interaction is derived and the interaction can be estimated for different chain length.
The interaction between two charged colloids depends on the amount of surface charge neutralized by polyelectrolytes. The interaction has a minimum when the surface charge is perfectly neutralized by polyelectrolytes. When the energy term dominates in a double layer... (More) - The interaction between two colloids with grafted polyelectrolytes in aqueous solution is studied within the primitive model by Monte Carlo simulations. For neutral colloids with grafted polyelectrolytes and in absence of salt the interaction is strongly repulsive in absence of salt. The interaction depends on the extension of the polyelectrolytes from the surfaces and the interaction is derived and the interaction can be estimated for different chain length.
The interaction between two charged colloids depends on the amount of surface charge neutralized by polyelectrolytes. The interaction has a minimum when the surface charge is perfectly neutralized by polyelectrolytes. When the energy term dominates in a double layer almost all ions are found in the vicinity of the charged surfaces forming alternating layers of counterions and coions. Coions have the same charge as the surface and counterions the opposite charge. The energy term becomes dominant at high surface charge density, low dielectric constant, low temperature or by reducing the entropy by a increasing the counterions valency. Another way to reduce the importance of the entropy is replace the counterions by polyelectrolytes. In the latter case the effect increases with the chain length.
If the polyelectrolytes are only grafted to one of two equally but oppositely charged surfaces a more long-range attraction occurs than if both surfaces are neutralized by either ions or polymers. The origin of this extra atrraction is the small ions, which are spread over the whole volume and causes a charge imbalance of the system. The MC results are shown to be in qualitatively agreement with results from surface force measurements. (Less) - Abstract (Swedish)
- Popular Abstract in Swedish
Den här avhandlingen handlar om interaktion mellan två ytor (t.ex. fibrer, lerpartiklar eller proteiner) i en vattenlösning med motjoner, salt och/eller polyelektrolyter. Polyelektrolyter är laddade polymerer. Avhandlingen är fokuserad på elektrostatisk växelverkan och interaktionerna har undersöks med hjälp av Monte Carlo-simuleringar. De kvalitativa resultaten har ofta jämförts med ytkraftsmätningar med god överensstömmelse.
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/38449
- author
- Sjöström, Lena LU
- supervisor
- opponent
-
- Stuart, Martien Cohen, Prof. Dept of Physical & Colloid Chemistry, Wageningen University, The Netherlands
- organization
- publishing date
- 1998
- type
- Thesis
- publication status
- published
- subject
- keywords
- electrostatic interaction, charge reversal, colloid, asymmetric systems, electric double layer, polyelectrolyte, Monte Carlo, Physical chemistry, Fysikalisk kemi
- pages
- 136 pages
- publisher
- Biophysical Chemistry (LTH), Lund University
- defense location
- Room D, Chemical Center, Lund
- defense date
- 1998-03-20 10:15:00
- external identifiers
-
- other:ISRN: LUTKDH/TKFK--98/1005--SE
- language
- English
- LU publication?
- yes
- additional info
- Article: Charge Reversal in Electric Double Layer - a Balancebetween Entropy and EnergyLena Sjöström, Torbjörn Åkesson and Bo JönssonBer. Bunsenges. Phys. Chem. 1996, 100 p 889. Article: Salt Effects on the Interaction between AdsorbedCationic Polyelectrolyte Layers - Theory and ExperminentMats A. G. Dahlgren, Åsa Waltermo, Eva Blomberg, Per M. Claesson,Lena Sjöström, Torbjörn Åkesson and Bo JönssonJ. Phys. Chem. 1993, 97, p 11769. Article: Interaction and Confromation of Polyelectrolyte ChainsAdsorbed on Neutral SurfacesLena Sjötröm, Torbjörn Åkesson and Bo JönssonJ. Chem. Phys. 1993, 99, p 4739. Article: The Stability of charged Colloids - AttractiveDouble Layer Forces due to Assymmetric Charge DistributionLena Sjöström and Torbjörn ÅkessonJ. Colloid Interface Sci. 1996, 181, p 645. Article: Attractive Osmotic Pressure in an Electric DoubleLayer with Grafted PolyelectrolytesJonathan Ennis, Lena Sjöström, Torbjörn Åkesson and Bo Jönssonaccepted for publication in J. Phys. Chem.
- id
- ae3f8bf6-d3d1-4f30-8f5f-2156d52e71a7 (old id 38449)
- date added to LUP
- 2016-04-04 11:29:04
- date last changed
- 2018-11-21 21:05:09
@phdthesis{ae3f8bf6-d3d1-4f30-8f5f-2156d52e71a7,
abstract = {{The interaction between two colloids with grafted polyelectrolytes in aqueous solution is studied within the primitive model by Monte Carlo simulations. For neutral colloids with grafted polyelectrolytes and in absence of salt the interaction is strongly repulsive in absence of salt. The interaction depends on the extension of the polyelectrolytes from the surfaces and the interaction is derived and the interaction can be estimated for different chain length.<br/><br>
<br/><br>
The interaction between two charged colloids depends on the amount of surface charge neutralized by polyelectrolytes. The interaction has a minimum when the surface charge is perfectly neutralized by polyelectrolytes. When the energy term dominates in a double layer almost all ions are found in the vicinity of the charged surfaces forming alternating layers of counterions and coions. Coions have the same charge as the surface and counterions the opposite charge. The energy term becomes dominant at high surface charge density, low dielectric constant, low temperature or by reducing the entropy by a increasing the counterions valency. Another way to reduce the importance of the entropy is replace the counterions by polyelectrolytes. In the latter case the effect increases with the chain length.<br/><br>
<br/><br>
If the polyelectrolytes are only grafted to one of two equally but oppositely charged surfaces a more long-range attraction occurs than if both surfaces are neutralized by either ions or polymers. The origin of this extra atrraction is the small ions, which are spread over the whole volume and causes a charge imbalance of the system. The MC results are shown to be in qualitatively agreement with results from surface force measurements.}},
author = {{Sjöström, Lena}},
keywords = {{electrostatic interaction; charge reversal; colloid; asymmetric systems; electric double layer; polyelectrolyte; Monte Carlo; Physical chemistry; Fysikalisk kemi}},
language = {{eng}},
publisher = {{Biophysical Chemistry (LTH), Lund University}},
school = {{Lund University}},
title = {{The Influence of Polyelectrolytes on the Stability of Colloids}},
year = {{1998}},
}