How long will a bubble be ?

TL;DR

This paper investigates the lifetime of soap bubbles floating on a liquid surface, demonstrating that larger bubbles last longer and that evaporation critically influences their duration, supported by experimental data and a theoretical model.

Contribution

It introduces a general equation for bubble lifetime based on lubrication theory, highlighting the role of evaporation in bubble rupture.

Findings

Larger bubbles have longer lifetimes.

Small bubbles exhibit more predictable lifetimes.

Evaporation is a key factor in bubble rupture.

Abstract

A soap bubble is a metastable object that eventually breaks. Indeed, the soapy water film thins until rupture, due to drainage and evaporation. In our experimental investigations, floating bubbles at the surface of a liquid bath have been considered. Their lifetime has been measured and reported with respect to their radius. Large bubbles last longer than small ones. Moreover, small bubbles have more predictable lifetimes than large ones. We propose a general equation for that lifetime, based on the lubrication theory. The evaporation is shown to be an essential process which determines the bubble lifetime.