Wetting dynamics describes the processes involved when a liquid spreads on a solid surface. It's an ubiquitous phenomenon in nature, for example when dew beads up on a leaf, as well as in many processes of industrial interest, from the spreading of paint on a wall to the development of high-performance coating processes in nanotechnology. Today, wetting dynamics is relatively well understood in the case of perfectly smooth, homogeneous model solid surfaces, but not in the case of real surfaces featuring roughness and/or chemical heterogeneity, for which fine modeling of the mechanisms remains a major challenge. The main goal of this thesis is to understand how nanometric roughness influences wetting dynamics.

This project is based on an interdisciplinary approach combining physics and surface chemistry. The PhD student will conduct systematic model experiments, combined with multi-scale visualization and characterization tools (optical microscopy, AFM, X-ray and neutron reflectivity, etc.).

Thanks to the complementary nature of the experimental approaches, this thesis will provide a better understanding of the fundamental mechanisms of energy dissipation at the contact line, from the nanometric to the millimetric scale.