Morphology evolution of liquid–gas interface on submerged solid structured surfaces

liquid–gas interface (LGI) on submerged solid structured surfaces is ubiquitous in nature and has various practical applications. The evolution, equilibrium, and stability of LGI are crucial to the underwater performances and functionalities of the surfaces, such as wetting, drag reduction, heat and mass transfer, etc., and have been studied for decades. In this review, we systematically summarize the underlying mechanisms of the morphology evolution of LGI on submerged solid structured surfaces under both quiescent and flow conditions. First, a thermodynamic framework for the analysis of the equilibrium and stability of submerged LGI in quiescent ambient is introduced. The conditions necessary to achieve equilibrium are surveyed. Then, both effects of hydrostatic pressure and gas diffusion on the morphology evolution of submerged LGI are reviewed. Some specific topics on interface morphologies, critical pressure, metastable state and gas diffusion equilibrium state are discussed. Finally, the morphology evolution of LGI under flow conditions is reviewed, including the effects of laminar and turbulent shear flow, and the flow enhanced gas diffusion.