A POSTECH research team investigated how an air bubble bursts and forms a liquid jet at air-liquid interface, making aerosols, small particles of several microns, in the air.

Professor Jung Ho Je of the Department of Material Science and Engineering developed the research with Research Prof. Byung Mook Weon and Ph.D candidate Ji San Lee. The result was published on Nature Communications, titled ‘Size limits the formation of liquid jets during bubble bursting.’

The phenomenon can be easily seen with a glass filled with soda. When bubbles go up, they burst and water aerosols are discovered as well. Produced aerosols act in many ways; they make up clouds and typhoons over the sea, and enter noses to make people smell liquids.

Using an X-ray microscope, the research team succeeded in capturing scenes of changing microscopic cells in the liquid by the microseconds. By analyzing them they could find how the bubble bursts and aerosols are produced physically.

At the moment when bubbles reach the surface, bubbles open and water surface becomes a little bit distorted. Because potential energy of distorted surface is larger than that of flat, water particles of the surface are rearranged. At that time, energy moves in the form of wave and it collides with each other at the bottom center of a bubble-shaped surface. Then, aerosols can be produced when the bubble is small enough or the liquid is not viscous enough.

Prof. Je expanded upon the meaning of research in that, “From this result, not only developments of integrated principles which can be applied to phenomena related to bubbles and water drops, but also control of bubbles in industries and improved climate models are expected.”