Review of Micronano Bubbles: Stability, Mass Transfer Performance, and Application

Abstract

Micronano bubbles (MNBs), as a gas–liquid system exhibiting unique advantages across multiple fields, have attracted considerable attention regarding their high stability and mass transfer performance. In this review, the generation, stability, mass transfer performance, and applications of MNBs in process intensification are summarized. With sizes in the micronano range, these bubbles are characterized by a slow rising velocity, prolonged residence time, and surface charges, contributing to their high stability. In terms of mass transfer performance, MNBs exhibit a high mass transfer coefficient and a large specific surface area, with mass transfer rates significantly surpassing those of conventional bubbles under certain conditions. However, the variation of the boundary layer thickness with bubble diameter warrants further investigation. Currently, MNBs have been applied in mineral flotation, water treatment, chemical engineering, and other fields, demonstrating improved processing efficiency and reaction effectiveness in specific scenarios. This review systematically elucidates the stability and mass transfer characteristics of MNBs and discusses their applications, offering theoretical insights and practical guidance for research and industrial implementation in related fields.