Interfacial mass transfer of single CO2 bubbles in viscoelastic liquids

Bubble velocity jump discontinuity is a distinctive characteristic of rising bubbles in the presence of viscoelasticity. This study reveals how interfacial mass transfer of single carbon dioxide bubbles stabilizes this discontinuity through two mechanisms. When bubbles experience sufficient exposure to elasticity, they shift smoothly from a high- to low-velocity branch, reproducing the behavior of non-dissolving bubbles with their pointed tip elongating downwards. Otherwise, they preserve the pointed tip and remain in the high-velocity regime even after shrinking to a size smaller than the critical one. These characteristics affect the liquid-side mass transfer coefficient, either enhancing it under the first mechanism or reducing it under the second one. The influence of viscoelasticity, bubble size, and dissolution time is characterized through empirical correlations incorporating the Weissenberg number, which are found accurate in estimating the bubble motion in viscoelastic liquids with dissolution. • CO 2 bubble dissolution in viscoelastic polyacrylamide solutions is investigated. • Two distinct dissolution mechanisms are revealed. • Critical dissolution time relative to relaxation time is identified. • Time-dependent mass transfer coefficient for bubble sizes of 3–5.5 mm is estimated. • Dimensionless correlations including viscoelasticity and dissolution are proposed.