Surface-mediated attraction between colloidsH. Kaïdi1, T. Bickel2 and M. Benhamou1
1 Laboratoire de Physique des Polymères et Phénomènes Critiques Faculté des Sciences Ben M'sik - B.P. 7955, Casablanca, Morocco
2 Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux 1 UMR 5798 - 351 cours de la Libération, 33405 Talence, France
received 27 July 2004; accepted in final form 28 October 2004
published online 8 December 2004
We investigate the equilibrium properties of a colloidal solution in contact with a soft interface. As a result of symmetry breaking, surface effects are generally prevailing in confined colloidal systems. In this letter, particular emphasis is given to surface fluctuations and their consequences on the local (re)organization of the suspension. It is shown that particles experience a significant effective interaction in the vicinity of the interface. This potential of mean force is always attractive, with range controlled by the surface correlation length. We suggest that, under some circumstances, surface-induced attraction may have a strong influence on the local particle distribution.
05.20.-y - Classical statistical mechanics.
82.70.-y - Disperse systems; complex fluids.
87.16.Dg - Membranes, bilayers, and vesicles.
© EDP Sciences 2005