Thin liquid or gas films are everywhere in nature, from foams to submillimetric bubbles at a free surface, and their rupture leaves a collection of small drops and bubbles. However, the mechanisms at play responsible for the bursting of these films is still in debate. The present study thus aims at understanding the drainage dynamics of the thin air film squeezed by gravity between a millimetric droplet and a smooth solid or a liquid thin film. Solving coupled lubrication equations and analyzing the dominant terms in the solid- and liquid-film cases, we explain why the drainage is much faster in the liquid-film case, leading often to a shorter coalescence time, as observed in recent experiments.

薄薄的液膜或气膜在自然界无处不在，从泡沫到自由表面上的亚微气泡，它们的破裂留下许多小滴和气泡。但是，导致这些电影破裂的机制仍在争论中。因此，本研究旨在了解在重力液滴和光滑的固态或液态薄膜之间受重力挤压的空气薄膜的排水动力学。解决了耦合润滑方程并分析了固态和液态膜情况下的主导项，我们解释了为什么在液态膜情况下排液要快得多，通常会缩短凝结时间，如最近的实验所示。