Analysis of pseudopartial and partial wetting of various substrates by lead.

Lead drops exhibit partial wetting on some substrates and pseudopartial wetting on others. In pseudopartial wetting, a film is in equilibrium with a capillary body with a nonzero contact angle. Using a free energy formulation appropriate for the experiments, we show the conditions under which minimization of the system energy is accurately achieved by minimizing the energy of the film alone. Using a set of simple surface energy isotherms, we explain the various wetting behaviors of lead. We contrast isotherms for autophobing systems and the metallic systems considered here.