New features of drops dynamics under Marangoni effect

Following initial observations in microgravity, laboratory experiments have been performed to investigate wetting and coalescence phenomena in presence of Marangoni effect. The problem was also investigated by numerical simulations based on the existence of a thin air film between the adjacent surfaces (liquid-liquid or liquidsolid) convected by the Marangoni velocities. This entrainment effect results in a pressure increase that balances the pressure necessary to prevent coalescence or wetting of the surfaces. A number of experimental findings and numerical simulations are reviewed, including anchored or free drops on solid or liquid surfaces, and the behaviour of droplets in liquid matrices. __________________________________________________________________R. Savino et al. 16