Surface stress and surface energy are two fundamental parameters that determine the surface properties of any materials. While it is commonly believed that the surface stress and surface energy of...

We investigate the dynamics of a drop containing a single solid particle impacting on a solid surface. The particle rebounds through the drop during impact and can separate from the deposited liquid above an impact velocity threshold. We show that this threshold can be predicted by a simple energy balance. Moreover, we discover a new type of liquid jetting ejected above the particle faster than the impact velocity. We demonstrate that this jetting is due to the focusing effect of the liquid on the solid substrate below the rebounding particle. Although the wetting properties of the particle have a minor effect on the separation threshold, they play a key role in the liquid jetting by affecting the immersion depth of the particle at the time of impact.

Small solid particles can be attached to an air–liquid interface due to the pulling of surface tension. We investigate experimentally under which conditions a spherical solid particle can be attached under a pendant drop, varying the density and diameter of the particle, as well as the size of the liquid drop. We demonstrate that depending on the drop size, the largest particle size that can be attached is limited by two different mechanisms, either falling from the nozzle together with the drop, or separating from the bottom of the liquid drop. Moreover, we show that for smaller volumes of the drop, a suction Laplace pressure can dramatically increase the maximum size of the particle that can be supported. Finally, we propose a theoretical model for each of these regimes to explain the maximum size of particle that can remain attached to a pendant drop.