Drop Ejection Research Articles

Aging and bursting bubbles in trace-contaminated water

The rise speeds and top jet drop ejection heights of rising and bursting bubbles in water are measured as a function of bubble age. Equivalent spherical diameters range from 0.08 < d < 0. 125 cm. Various types of relatively surfactant-free water are used. Both rise speeds and top jet drop ejection heights decrease with bubble age. This is due to adsorption of surface-active materials on the bubble surface which increases the rigidity of the surface and decreases its surface free energy. In general, terminal values of rise speed and ejection height are not reached at the same bubble age. The ages at which these terminal values are reached are characteristically greater for larger bubbles in a given water sample. These ages are also characteristically greater for bubbles of a given size as the concentration of surface-active material in the water decreases.