Modeling of bubble nucleation of an air–water mixture near hydrophobic walls

Abstract

In this work, a density functional approach is applied to calculate the interfacial thermodynamic properties of an air–water mixture in the presence of a hydrophobic wall. Without any mixing parameter, the theoretical model can correctly reproduce the measured interfacial tensions of a nitrogen–water binary mixture. The density profiles of the dissolved air and water near the hydrophobic walls are predicted using the validated model. It is shown clearly that a hydrophobic wall leads to air enrichment and water depletion. According to the extent of air enrichment, the free energy barriers and critical radii of bubble nucleation at different hydrophobic interfaces are calculated to evaluate the possibility of spontaneous bubble nucleation.