NUCLEATION OF WETTING LAYERS

Using Nakanishi and Fisher's model [Phys. Rev. Lett. 49, 1565 (1982)] for the wetting of a liquid on a substrate, we calculate the structure and free energy of critical circular domains. The first creation of critical domains denotes the onset of the nucleation of the wetting layer from a metastable surface state. It is shown that at the metastable limit, where the metastable surface state ceases to exist, the free energy and height of the critical domain vanish while the radius of the critical domain diverges. First-order corrections in an expansion in S, the surface tension difference between the metastable and the equilibrium surface state, to the usual thermodynamic analysis are calculated. As a result we have that, at coexistence, the nucleation time is given by ΔtS8πRexp(πτ2/kTS), where τ is the line tension at the wetting transition and R is the rescaled surface tension of the liquid-vapor interface that is universal (R0.10) near the critical temperature. © 1995 The American Physical Society.