npj Microgravity Brief Communication: How antifoams act: a microgravity study
This article by Pavel Yazhgur, Dominique Langevin, Vincent Klein, Emmanuelle Rio and Anniina Salonen (Université Paris Sud—CNRS UMR, Orsay, France) and Hervé Caps (Université de Liège, Liège, Belgium) was published online by npj Microgravity on May 27, 2015.
Antifoams are widely used to control or to avoid foam production. In order to work, antifoam particles need to break foam films efficiently, which many antifoams do very well. However, once they have broken a film, to continue to be effective they need to be transported to the next film. We show, for the first time, that buoyancy has an important part in the transport of the antifoam particles. In microgravity, where buoyancy and gravitational drainage are strongly slowed down, diffusion leads to poor antifoam performance. The foam is stable for the duration of the experiment, whereas on Earth the foam starts to disappear immediately. Indeed, microgravity renders highly efficient antifoam practically useless.