The Effect of Surfactant on a Rising Bubble

Abstract

The behavior of a single bubble rising in water with some surfactant dissolved is analyzed numerically and experimentally. Marangoni effect due to adsorption of the surfactant is taken into consideration. As a surfactant, 1-Pentanol, 3-Pentanol, 2-Octanol, Triton X-100 is chosen. And then, it is found that the bubble motion strongly depends on the physical properties of each surfactant such as kinetic constant, desorption constant, saturation adsorption etc. It showed good agreement of drag coefficient between experimental result and numerical one, even for narrow transient area from clean bubble to rigid sphere. In addition, a new method is proposed to estimate unknown surface properties of surfactant in water.