Metastable States and Nucleation near First-Order Wetting Transitions

Ellipsometry experiments on wetting in a binary liquid mixture show that the thick wetting film can be undercooled below the first-order transition temperature and has an anomalously long lifetime. Also, a metastable thin film can be observed in the experiments with a much shorter lifetime. We employ a simple theory to calculate the wetting and prewetting phase diagram, including the spinodals of the first-order surface transition. The location of the spinodals in the phase diagram provides us with qualitative information on the lifetimes of metastable states, which agrees with the experiments.