Scientists have managed to bounce a water drop on dry ice, showing a low temperature analogue of the well-known Leidenfrost effect. The process was captured in this rather pleasing video showing the drop rebounding. The vortex ring that can be seen is created by the droplet as it moves through water vapour which has condensed at the cold carbon dioxide surface.
In the Leidenfrost effect, a liquid collides with a surface much hotter than its boiling point, forming a protective cushion of gas that also becomes an insulating layer, slowing further evaporation. Scientists at the University of Bergano and ETH Zurich, found that liquid water bounced off dry ice at -79°C, just like it does off a hot plate at 300°C, because the gaseous CO2 layer between the droplet and the surface pushes the drop back without it freezing.
No comments yet