Capillary interaction between floating particles

When we consider small particles floating on a liquid, deformation of interface creates interactions between particles due to capillarity. For identical floating spheres, attraction is observed and we characterized experimentally the dynamics of aggregation in order to clarify origin of attractions. For millimeter sized particles we found that viscous hydrodynamic interactions and contact friction play a crucial role in aggregation mechanisms.

Experiment performed by Darija Cosic

Video of cluster rearrangement (Experiment performed by Marie-Julie Dalbe)

Structure of capillary aggregates

Moreover a new experiment was developed, where we use capillary attraction to generate a two dimensional cohesive granular medium. This system was submitted to a homogeneous compression and we follow the structural changes as a function of area fraction. Initial structure presents larges pore stabilized by friction and dense regions with a small scale order. When system is compressed, heterogeneity is decreased by the disappearance of pores and structure of non cohesive granular media is reached.


Related publications :

Documents :

Slides of a presentation given at Liege University (March 2011)

Slides of a presentation given at Georgetown university (August 2010)

Slides of a presentation at the 7th Northeastern Granular Materials Workshop (June 2009)

Slides of a presentation at the APS DFD meeting (November 2009)

Slides of a seminar at Center for Fluid Mechanics Seminar (May 2010) at Brown university

Movies of compression of capillary aggregates : N=328, N=688, N=1139.