State transition of stable nanobubbles to unstable microbubbles on homogeneous surfaces

Abstract

The widely accepted Epstein-Plesset theory (EPT) suggests that all gas bubbles are diffusively unstable in practical situations of accelerative shrinkage or unbounded growth. The stable nanobubbles confirmed by experiments go against EPT, which is verified by experiments on bubble radii down to micrometers. The theoretical gap between stable nanobubbles and unstable microbubbles requires a full-scale physical understanding. We present a model that describes the state transition from stable nanobubbles to unstable microbubbles on homogeneous surfaces, achieving diffusive equilibrium at the liquid-bubble interface and mechanical equilibrium at the triple-phase contact line simultaneously.