Bubble rupture plays an important role in aerosol generation and mass transfer processes taking place at air water interface. Applications can be found in Marine aerosol generation, transportation of bacteria and harmful substances from water bodies and chemical processes, such as froth floatation, degassing etc.
Bubble rupture is a fast phenomenon lasting only a few milliseconds. Film thickness of bubble film is of the order of microns. It involves intricate physics including intermolecular instabilities and interfacial forces. These characteristics make the experimental study of bubble rupture a challenge. In the past, researchers have postulated two differing mechanisms involved in bubble rupture. A few suggested that bubble film breaks up uniformly and film drops are produced when the mass hits the edge of bubble. On the other hand, others contradicted by saying that bubble rupture is a random spontaneous event which is a consequence of film instabilities and film drops are fragments of liquid ligaments. In lieu of high speed photographical evidence, both of hypotheses were flawed and lacked time based experimental observations.
The present work is aimed at studying the entire bubble rupture process by means of high speed photography and studying the effect of surface tension, bubble diameter and the location of initial rupture. The experiments were carried out with water and ethanol representing the effect of surface tension. High visualization images were analyzed to find out the rupture velocity of the bubbles. It was found that the bubble undergoes film rolling and then toroids breakage to release film drops. Therefore, it can be concluded that above mentioned theories were valid only for certain conditions.