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Attractive Forces between Charged Colloidal Particles Induced by Multivalent Ions Revealed by Confronting Aggregation and Direct Force Measurements
- Source :
- Journal of Physical Chemistry Letters, Vol. 4, No 4 (2013) pp. 648-652
- Publication Year :
- 2013
- Publisher :
- American Chemical Society (ACS), 2013.
-
Abstract
- Interactions involving charged particles in the presence of multivalent ions are relevant in wide-range of phenomena, including condensation of nucleic acids, cement hardening, or water treatment. Here, we study such interactions by combining direct force measurements with atomic force microscopy (AFM) and aggregation studies with time-resolved light scattering for particles originating from the same colloidal suspension for the first time. Classical DLVO theory is found to be only applicable for monovalent and divalent ions. For ions of higher valence, charge inversion and additional non-DLVO attractive forces are observed. These attractive forces can be attributed to surface charge heterogeneities, which leads to stability ratios that are calculated from direct force measurements to be higher than the experimental ones. Ion-ion correlations are equally important as they induce the charge inversion in the presence of trivalent or tetravalent ions, and they enhance the surface charge heterogeneities. Such heterogeneities therefore play an essential role in controlling interactions in particle suspensions containing multivalent ions.
- Subjects :
- Multivalent ions
Surface forces
Chemistry
Surface force
Light scattering
Colloidal probe technique
Charged particle
Ion
Condensed Matter::Soft Condensed Matter
Atomic force microscopy
Colloid
Chemical physics
ddc:540
DLVO theory
General Materials Science
Surface charge
Physical and Theoretical Chemistry
Atomic physics
Particle stability
Subjects
Details
- ISSN :
- 19487185
- Volume :
- 4
- Database :
- OpenAIRE
- Journal :
- The Journal of Physical Chemistry Letters
- Accession number :
- edsair.doi.dedup.....6245a6c52c2c15d019b6c0d273c9cde8