Temperature Response of Charged Colloidal Particles by Mixing Counterions Utilizing Ca2+/Na+ Montmorillonite as Model System
(2017) In Journal of Physical Chemistry C 121(14). p.7951-7958- Abstract
The osmotic pressure and the aggregation of charged colloids as a function of temperature have been investigated using Monte Carlo and molecular dynamics simulations for different ratios of monovalent and divalent counterions. In the simulations the water is treated as a temperature-dependent dielectric continuum, and only the electrostatic interactions are considered. It was found that the temperature response can be controlled, i.e., the osmotic pressure can increase, decrease, or be kept constant, as a function of temperature depending on the monovalent/divalent counterion ratio. The increase in osmotic pressure with temperature, which occurs at low enough surface charge density and/or low fraction of divalent ions, can be understood... (More)
The osmotic pressure and the aggregation of charged colloids as a function of temperature have been investigated using Monte Carlo and molecular dynamics simulations for different ratios of monovalent and divalent counterions. In the simulations the water is treated as a temperature-dependent dielectric continuum, and only the electrostatic interactions are considered. It was found that the temperature response can be controlled, i.e., the osmotic pressure can increase, decrease, or be kept constant, as a function of temperature depending on the monovalent/divalent counterion ratio. The increase in osmotic pressure with temperature, which occurs at low enough surface charge density and/or low fraction of divalent ions, can be understood from the DLVO theory. The origin of the opposite behavior can be explained by the enhanced attractive electrostatic ion-ion correlation interactions with temperature. The constraint is that the absolute value of the surface charge density of the colloids must be above a certain threshold, i.e., high enough such that the attractive ion-ion correlations can dominate the interaction regarding the divalent ions. The current conclusions are supported by the microstructural characterization of Ca2+/Na+-montmorillonite clay using small-angle X-ray scattering. A qualitative agreement is observed between the simulations and the experimental data.
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- author
- Thuresson, Axel LU ; Jansson, Maria LU ; Plivelic, Tomás S. LU and Skepö, Marie LU
- organization
- publishing date
- 2017-04-13
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry C
- volume
- 121
- issue
- 14
- pages
- 8 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85019996566
- wos:000399629000040
- ISSN
- 1932-7447
- DOI
- 10.1021/acs.jpcc.7b00882
- language
- English
- LU publication?
- yes
- id
- 990102e6-c05d-4bf0-b346-26cf557de026
- date added to LUP
- 2017-06-28 15:56:42
- date last changed
- 2024-09-16 04:10:01
@article{990102e6-c05d-4bf0-b346-26cf557de026, abstract = {{<p>The osmotic pressure and the aggregation of charged colloids as a function of temperature have been investigated using Monte Carlo and molecular dynamics simulations for different ratios of monovalent and divalent counterions. In the simulations the water is treated as a temperature-dependent dielectric continuum, and only the electrostatic interactions are considered. It was found that the temperature response can be controlled, i.e., the osmotic pressure can increase, decrease, or be kept constant, as a function of temperature depending on the monovalent/divalent counterion ratio. The increase in osmotic pressure with temperature, which occurs at low enough surface charge density and/or low fraction of divalent ions, can be understood from the DLVO theory. The origin of the opposite behavior can be explained by the enhanced attractive electrostatic ion-ion correlation interactions with temperature. The constraint is that the absolute value of the surface charge density of the colloids must be above a certain threshold, i.e., high enough such that the attractive ion-ion correlations can dominate the interaction regarding the divalent ions. The current conclusions are supported by the microstructural characterization of Ca<sup>2+</sup>/Na<sup>+</sup>-montmorillonite clay using small-angle X-ray scattering. A qualitative agreement is observed between the simulations and the experimental data.</p>}}, author = {{Thuresson, Axel and Jansson, Maria and Plivelic, Tomás S. and Skepö, Marie}}, issn = {{1932-7447}}, language = {{eng}}, month = {{04}}, number = {{14}}, pages = {{7951--7958}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Journal of Physical Chemistry C}}, title = {{Temperature Response of Charged Colloidal Particles by Mixing Counterions Utilizing Ca<sup>2+</sup>/Na<sup>+</sup> Montmorillonite as Model System}}, url = {{http://dx.doi.org/10.1021/acs.jpcc.7b00882}}, doi = {{10.1021/acs.jpcc.7b00882}}, volume = {{121}}, year = {{2017}}, }