Receding contact lines in water-ice systems*

This presentation will be about theoretical and experimental investigations on the wetting behavior of water on ice. Several previous experimental observations and theoretical considerations points towards the idea that the ice-water system is not perfectly wetting. However, investigating that phenomenon systematically using classical techniques used to measure wettability is an experimental challenge, as ice and liquid water are usually not at equilibrium when coexisting. Our experiments force a well-controlled out-of-equilibrium situation, namely the receding motion of a contact line on a vertical plate of ice, and we compare the results with a model for the solidifying film. Our results show that solidification allows contact lines to stay stationary in regimes of the capillary number that are out of reach for inert systems. These results also point towards the idea that water does not perfectly wet ice.