69th Annual Meeting of the APS Division of Fluid Dynamics (November 20, 2016 — November 22, 2016)

V0036: Periodic Puffs from Dissolving Dropplets

Authors

• Erik Dietrich, Physics of Fluids and Physics of Interfaces and Nanomaterials Groups of the University of Twente
• José Manuel Encarnación Escobar, Physics of Fluids Group of the University of Twente
• Harold J.W. Zandvliet, Physics of Interfaces and Nanomaterials Group of the University of Twente
• E. Stefan Kooij, Physics of Interfaces and Nanomaterials Group of the University of Twente
• Detlef Lohse, Physics of Fluids Group of the University of Twente

DOI: https://doi.org/10.1103/APS.DFD.2016.GFM.V0036

If we take an hydrophobic substrate, immerse it in water and place a droplet of oil soluble in water we will observe the dissolution in stick-jump mode characterized by the intermittent contact line pinning at surfaces heterogeneities. However, if we now take an identical oil droplet placing an air bubble inside the droplet the drop will dissolve as expected until the surface of the drop and the bubble become close enough producing a curious effect. This is caused by a sort of effects driven by the Marangoni surface tensions, the contact angles and the change of dissolution speed of the water-soluble oil caused by the saturation of the water and the later income of fresh pure water. We hope that you enjoy the video showing this phenomenon that we find both fun and interesting because of the implications of many different universal and well known behaviors in an unusual equilibrium.