The objective of this study is to investigate the dynamics of flows occurring in the wakes of rising bubbles of different shapes and sizes. Different wake dynamics can result in qualitatively different mixing characteristics. In the case of fast gas-liquid reaction networks, reactions occur almost exclusively in the bubble wake. Thus, wake mixing can have a strong impact on the reaction yield and selectivity. Dynamic numerical simulations were performed to study the flow of liquid around bubbles of different shapes. The obtained velocity and pressure fields were used to investigate the liquid-phase mixing in the flow for each case. As a strong connection between mixing and chaos is known to exist, Lagrangian tracking of passive tracer particles was used to identify chaotic fluid transport in the flows. Chaotic dynamics lead to folding and stretching of fluid elements, which results in very effective mixing. To quantify mixing, stretching fields were computed for each flow case. Finally, different liquid-phase chemical reaction networks were tested to illustrate the effects Of Mixing on chemical reaction yields and selectivities. (C) 2004 Elsevier Ltd. All rights reserved.