Drop-solid retention forces

A crucial parameter in cooling using drops is the drop retention forces, which will determine the size of the drop that will fall down. In this talk we will describe a method to study such forces systematically. We will define a new parameter that can describe the lifetime of coatings of solids as the liquid contacting them causes a slow degradation. The paper includes normal adhesion and lateral adhesion. The first relates to the work (energy) that is required to detach a liquid from a solid in the direction normal to the solid. The second relates to the case in which a drop is sliding along a solid surface. In most systems, the process of drop detachment from a solid surface is a combination of both normal and lateral adhesion. Initially, the drops slide on the solid, in which case the important parameter is the lateral adhesion, and eventually, there will be a drop detachment from the solid surface due to body forces (e.g. gravitational forces). A full understanding of the process, therefore, requires understanding of both parameters.