Slug bubble growth and dissolution by solute exchange

Abstract

Mass transfer of gases in liquid solvents is a fundamental process during bubble generation for specific purposes or, vice versa, removal of entrapped bubbles. In our work, we address the growth dynamics of a trapped slug bubble in a vertical glass cylinder under a water barrier after replacing the ambient air atmosphere by a CO${}_{2}$ atmosphere at the same or higher pressure. The asymmetric exchange of the gaseous solutes between the CO${}_{2}$-rich water barrier and the air-rich bubble always results in net bubble growth, which we call solute exchange. We compare and explain the experimental results with a simple numerical model, with which the underlying mass transport processes are quantified.