Eur. Phys. J. E (2008) 26: 151-160
https://doi.org/10.1140/epje/i2007-10314-1

ISMC-2007

Ellipsoidal particles at fluid interfaces

¹ Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, D-70569, Stuttgart, Germany
² Institut für Theoretische und Angewandte Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569, Stuttgart, Germany
³ Institut für Physik, WA 331, Johannes-Gutenberg-Universität Mainz, D-55099, Mainz, Germany

^* e-mail: oettelm@uni-mainz.de

Received: 20 September 2007
Accepted: 17 March 2008
Published online: 2 May 2008

Abstract

For partially wetting, ellipsoidal colloids trapped at a fluid interface, their effective, interface-mediated interactions of capillary and fluctuation-induced type are analyzed. For contact angles different from 90^° , static interface deformations arise which lead to anisotropic capillary forces that are substantial already for micrometer-sized particles. The capillary problem is solved using an efficient perturbative treatment which allows a fast determination of the capillary interaction for all distances between and orientations of two particles. Besides static capillary forces, fluctuation-induced forces caused by thermally excited capillary waves arise at fluid interfaces. For the specific choice of a spatially fixed three-phase contact line, the asymptotic behavior of the fluctuation-induced force is determined analytically for both the close-distance and the long-distance regime and compared to numerical solutions.