Nanodroplets wetting an elastic half-space.

Abstract

Wetting of deformable surfaces is a highly debated topic in interface science. A classical approach employing the localized Young's traction <i>γ</i>sin<i>θ</i> and curvature-induced traction following from the spherical cap assumption, is commonly used for the evaluation of the deformation - particularly, a wetting ridge - of the surface. This, however, does not provide insight into the nanophysics behind the soft wetting, and the effect the surface forces have on the wetting ridge geometry is still poorly understood. In the present paper, we use the disjoining pressure concept to study statics and dynamics of nanoscale droplets on elastic, infinitely thick surfaces. We show that the wetting ridge tip geometry does depend on the surface forces. We demonstrate that when the droplet comparable with the range of the surface force action spreads, the wetting ridge evolves in a way that its maximal height and solid angle changes with time non-monotonically.