Outcomes from a drop impact on solid surfaces

A qualitative analysis of the various outcomes of a drop impact on solid surfaces with different roughness and wettability is carried out. Water, ethanol, different mixtures of glycerin and water, liquid alloys, and silicone oil were used to provide a wide range of material properties such as surface tension, viscosity, and density. The impact velocity was varied by moving the drop generator vertically with respect to the plate. Also two drop diameter classes were considered. A variation of roughness amplitude and wavelength was achieved using a laser ablation process on polyvinyl chloride and glass substrates, creating a deterministic microstructure. A highly nonwettable rough surface was prepared with alkylketene dimer (AKD) [1]. A first classification of the different outcomes, in terms of splash, rebound, partial rebound, deposition, and other features, is presented.