DIVERGING LENGTH SCALES AT FIRST-ORDER WETTING TRANSITIONS

The singular behavior of the equilibrium line tension at first-order wetting transitions can be understood as a critical phenomenon with diverging length scales. Also, near the wetting transition the decay of a metastable nonwet state is accompanied by the divergent length scales of the unstable critical droplet. We discuss the relationship between these two sets of diverging lengths and verify a scaling hypothesis for the singular part of the line tension and a generalized Laplace equation for critical droplets. For sufficiently long-ranged forces the equilibrium and nonequilibrium lengths are governed by the same universal laws, whereas for short-ranged forces the results indicate a distinct nonequilibrium universality class.