Annihilating Foam Using an Applied Voltage

Here we discuss a voltage-driven mechanism of foam breakage - a method free from chemicals and mechanical components, that could be pivotal in settings like bioreactors. We provide direct experimental evidence of the origin of the foam rupture: hydrogen evolution at the cathode, where a proton deficit reduces surface tension, triggering localized Marangoni flows leading to cascade of bubble ruptures. Two operational regimes are identified: one where foam breakage conforms to natural evaporation rates and another where it accelerates (at least) eightfold beyond a critical electrolysis voltage. The latter regime reveals constant breakage rates, a feature that underscores a lack of electrokinetic effects. Finally, building on our mechanistic findings, we engineer a bench-scale foam mitigator designed for continuous foam suppression using electrolysis.