SIze distribution of merging bubbles*

The stability of soap bubbles is of crucial importance in many applications. In previous studies, the drainage of bubble walls has been widely investigated. In this study, by switching gears, we focus on the temporal evolution of distribution of bubble size. Using the solution of commercial dishsoap at various concentrations from 0.1% to 10%, we captured the time-lapse videos of the bubble coalescence process up to 5 hours. The results show that the bubbles are most stable when the solution has the concentration of 0.5%. Also, we find that the larger bubbles decay faster than smaller ones, and the decay roughly follows the exponential curve in time.