Frost nucleation, growth and propagation on a hydrophobic surface*

We report experimental results on the condensation of water vapor on a substrate (-9~$^{\circ}$C) at supercooled conditions. The resulting breath figure grows until the liquid to solid phase transition takes place. The frost seeds start to grow by deposition at the expense of neighboring supercooled water drops that evaporate. Sometimes the propagation (due to the growth of the ice) is faster than the evaporation of the drops, hence they transit to the solid state via a percolation mechanism. In this work [1], we analyze the growth of supercooled condensed drops (first stage), the growth of the ice crystals and the evolution of the supercooled water drops (intermediate and late stages). We also consider the liquid - solid front propagation (growth of the frost figure).\\[4pt] [1] J. Guadarrama-Cetina, A. Mongruel, W. Gonz\'alez-Vi\~nas, D. Beysens. In preparation