Nucleated wetting layers

Abstract

We observe a new wetting layer growth mechanism at the liquid/vapor surface of the critical mixture acetone+hexadecane. After spinodal decomposition of the bulk liquid, a metastable surface state forms. This metastable state is consistent with critical adsorption and persists until a wetting film or droplets of the lower phase are nucleated at the surface. Film growth occurs for ΔT=${\mathit{T}}_{\mathit{c}}$-T0.1 °C. The droplet nucleation time is consistent with classical nucleation theory provided the droplet line tension, scrL, is included in the surface free energy. We determine that scrL∼${\mathit{t}}^{0.83}$ close to ${\mathit{T}}_{\mathit{c}}$ where t is the reduced temperature.