The Thermodynamics of Restoring Underwater Superhydrophobicity

Superhydrophobic surfaces submerged in liquids are susceptible to permanently becoming wet. This is especially true when the ambient liquid is pressurized or undersaturated with air. To gain insight into the thermodynamics of restoring underwater superhydrophobicity, nucleation theory is applied to the design of spontaneously dewetting conical pores. It is found that, for intrinsically hydrophobic materials, there is a geometric constraint for which reversible superhydrophobic behavior may occur. Molecular dynamics simulations are implemented to support the theory, and steered molecular dynamics simulations are used to investigate the energy landscape of the dewetting process. The results of this work have implications for the efficacy of underwater superhydrophobicity and enhanced nucleation sites for boiling heat transfer.