Drainage and convective evaporation of thin films in the presence of salt
We investigate the effect of salinity and atmospheric humidity on the drainage and lifetime of soap films in conditions relevant to air-sea mass exchanges. We show that the drainage is independent of humidity and that the effect of a change in salinity is only reflected through the associated change in viscosity. On the other hand, film lifetime displays a strong dependence on humidity, with more than a tenfold increase between low and high humidities. We additionally show that mixing the air surrounding the film has a very important effect on lifetime, improving repeatability and reducing the mean lifetime of the film. From estimations of the evaporation rate, we are able to derive scaling laws that describe well the evolution of lifetime with a change of humidity.
Contact Nathanaël Machicoane for more information or to schedule a discussion with the seminar speaker.