Equilibrium contact angle at the wetted substrate

We construct a novel model for the steady-state contact angles of liquid droplets at wetted substrate. The non-removable, thin film covering substrate is governed by intermolecular forces between molecules and solid, which we describe using standard disjoining pressure approximation. Balancing against surface tension, find smooth shape liquid. show that can extract an effective angle from region where droplet meet. Crucially, large independent size. Instead, determined tension parameters through simple formula works both small angles. suggest comparing predictions our to experimentally measure will enable constraining models.