Bubble breakup and effects of soluble surfactants on bubble dynamics in a solid-body rotating flow

We present experimental results describing the behavior of a bubble placed within a horizontal high-speed solid-body rotating flow. We focus on the stretching and breakup of the bubble that happens in this situation and on the effect that a surfactant introduced in the liquid has on this. In order to explore the effects of surfactants on the bubble we have used two solutions of tetradecyltrimethylammoniumbromide (TTAB), one whose concentration is lower than the critical micelle concentration (0.33 CMC) and one with a concentration larger than the CMC (2 CMC). The results show that, as expected, the deformation of the bubble is larger in both surfactant solutions than in water and can be modeled by the model of Rosenthal 1962 in the case of both solutions. In the case of the 0.33 CMC solution, the bubble behaves as if it were seeing an effective surface tension equal to that in the saturated solution. We observed that the bubble could break up at certain rotational speeds for large bubble sizes. We show that this breakup occurs through a resonance mechanism when the rotational velocity of the tank becomes of the order of the eigenfrequency of the bubble.