Dissolution kinetics of bulk nanobubbles derived from modified Epstein-Plesset theory

The dissolution dynamics of bulk nanobubbles (BNBs), which are submicron gas domains dispersed in solution, represent a complex and intriguing area of contemporary scientific research involving a multitude of interactions. While the classical Epstein-Plesset (EP) theory provides a foundational framework for understanding bubble dissolution and growth, it falls short in explaining the long-term stability of BNBs due to the pronounced effects of surface tension at nanometer scales. In this review, we refine the EP theory by first expanding our focus from the intrinsic physical properties of BNBs, such as high internal gas density, to the unique characteristics of the BNB interface, including modifications of surface tension and the non-zero polarization of water molecules. We then consider the effects of extrinsic adsorption, such as surface charges and surfactants, to explore how these factors contribute to the stability of BNBs. In particular, we analyze nanoscale surface tension variations and determine that, under Tolman-dependent surface tension, an equilibrium solution with a radius of 34 nm is achieved, which is consistent with sizes of ultra-small NBs reported by experiments. Additionally, we present a model addressing the role of water molecule polarization in BNB stability, revealing that a polarization orientation probability of 0.1448 results in an equilibrium solution for BNBs. This review aims to advance current EP theory to enhance our understanding of the stability of BNBs as observed in experiments, thereby providing a robust theoretical basis for their applications across various fields.