Pinching Dynamics of Thin Films of Binary Mixtures

Abstract

In binary mixtures, the lifetimes of surface bubbles can be five orders of magnitude longer than those in pure liquids because of slightly different compositions of the bulk and the surfaces, leading to a thickness-dependent surface tension of thin films. Taking profit of the resulting simple surface rheology, we derive the equations describing the thickness, flow velocity and surface tension of a single liquid film. Numerical resolution shows that, after a first step of tension equilibration, a parabolic flow with mobile interfaces is associated with film pinching in a further drainage step. Our model paves the way for a better understanding of the rupture dynamics of liquid films.