Influence of a surfactant on bubble bursting
E. J. Vega, J. M. Montanero
Abstract
We study the bursting of a bubble covered with a surfactant experimentally. We conclude that the bubble bursting takes longer than that of a surfactant-free bubble with the same equilibrium surface tension due to the interfacial elasticity. A tiny bubble is formed at the cavity bottom right before the free surface reversal due to the Marangoni stress. This stress also drives the liquid flow that makes the jet escape from the end-pinching mechanism for a certain surfactant concentration interval. A diminutive liquid droplet manages to escape from the jet for a sufficiently large surfactant concentration. This droplet is much smaller than its surfactant-free counterpart but moves at a similar speed. The surfactant molecules are convected toward the jet tip so that the monolayer covering the first-emitted droplet is practically saturated.