Berlin 2005 – scientific programme
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CPP: Chemische Physik und Polymerphysik
CPP 22: Colloids
CPP 22.5: Talk
Tuesday, March 8, 2005, 12:15–12:30, TU C243
Effective capillary interaction of colloidal particles at fluid interfaces — •Martin Oettel1, Alvaro Dominguez1,2, and Siegfried Dietrich1 — 1Max–Planck–Institut für Metallforschung, Heisenbergstr. 3, D–70569 Stuttgart, Germany — 2Fisica Teorica, Dept. FAMN, Apartado 1065, E-41080 Sevilla, Spain
We present an analysis of the effective force between two
smooth spherical colloids floating at a fluid interface due to
deformations of the interface. The results hold in general and are
applicable independently of the source of the deformation provided
the capillary deformations are small so that a
superposition approximation for the deformations is valid. We
conclude that an effective long–ranged attraction is possible if the
net force on the system does not vanish. Otherwise, the interaction
is short–ranged and cannot be computed reliably based on the
superposition approximation.
As an application, we consider the case of like–charged, smooth
nanoparticles and electrostatically induced capillary
deformation. The resulting long–ranged capillary attraction can be easily
tuned by a relatively small external electrostatic field, but it
cannot explain recent experimental observations of attraction if these
experimental systems were indeed isolated.
M. Oettel, A. Dominguez and S. Dietrich, cond-mat/0411329.