Dynamics of heterogeneous wetting in periodic hybrid nanopores.

We present experimental and theoretical results concerning the forced filling and spontaneous drying of hydrophobic cylindrical mesopores in the dynamical regime. Pores are structured with organic/inorganic moieties responsible for a periodicity of the surface energy along their axis. We find that the forced intrusion of water in these hydrophobic pores presents a slow dynamics: the intrusion pressure decreases as the logarithm of the intrusion time. We find that this slow dynamics is well described quantitatively by a classical model of activated wetting at the nanoscale, giving access to the structural length scales and surface energies of the mesoporous material.