期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：10
页码：2515-2519
DOI：10.1073/pnas.1616904114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We study the effect of gravity on giant soap bubbles and show that it becomes dominant above the critical size ℓ = a 2 / e 0 , where e 0 is the mean thickness of the soap film and a = γ b / ρ g is the capillary length ( γ b stands for vapor–liquid surface tension, and ρ stands for the liquid density). We first show experimentally that large soap bubbles do not retain a spherical shape but flatten when increasing their size. A theoretical model is then developed to account for this effect, predicting the shape based on mechanical equilibrium. In stark contrast to liquid drops, we show that there is no mechanical limit of the height of giant bubble shapes. In practice, the physicochemical constraints imposed by surfactant molecules limit the access to this large asymptotic domain. However, by an exact analogy, it is shown how the giant bubble shapes can be realized by large inflatable structures.
