Wetting and Contact Lines of Micrometer-sized Ellipsoids

coauthor: Jean Christophe Loudet, Centre de Recherche Paul Pascal
published: Dec. 22, 2007,   recorded: November 2007,   views: 3667

Related Open Educational Resources

Related content

Report a problem or upload files

If you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.
Lecture popularity: You need to login to cast your vote.


We experimentally and theoretically investigated the wetting of a fluid interface on solid micrometer-sized ellipsoidal particles. The latter were obtained from uniaxial stretching of monodisperse polystyrene spheres (radius R = 5m) and the aspect ratio, k, was varied from 1 to about 10. We have demonstrated that such ellipsoids at oil-water interfaces manifest long range capillary interactions of considerable energies, up to about 105 times the thermal energy. The contact line exhibits saddle-like deformations and has a quadrupolar symmetry: the interface is pulled down near the tips of the ellipsoid and pulled up near the middle of the particle. Two ellipsoids attract each other tip to tip or side by side but repel one another when in a side-to-tip configuration. These trends are indeed in line with the general rule according to which the interaction between capillary charges of the same sign is attractive while it is repulsive between charges of opposite signs. To interpret our experimental data, we numerically solved the partial wetting problem on a single ellipsoid and found that the contact line is indeed a saddle-shaped curve with a quadrupolar symmetry. Furthermore, comparisons of experimental and simulated data allowed us to determine contact angles and rather unexpectedly, the latter were found to decrease significantly with increasing ellipsoid aspect ratio.

Link this page

Would you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !

Write your own review or comment:

make sure you have javascript enabled or clear this field: