Ionic correlations in highly charge-asymmetric colloidal liquids.
We use electrophoretic mobility (mu) measurements of charged colloidal particles under the presence of multivalent counterions as a probe of the electrostatic correlations between them; they become important for sufficiently high surface charge densities of the colloid (sigma) and result in a decreasing mu upon increasing sigma. The physics of this decrease is the same as that giving rise to charge inversion. We account qualitatively for the observations by considering recent theoretical arguments that assume the counterions next to the colloid surface as a strongly correlated liquid of properties similar to that of a Wigner crystal.
Fernández-Nieves
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Group of Complex Fluids Physics, Department of Applied Physics, University of Almería, 04120 Almería, Spain. afnieves@ual.es
Fernández-Barbero
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de Las Nieves
F J
FJ
Vincent
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