2016/01/01 by Etienne Jambon-Puillet, Dominic Vella, Suzie Protière
Engineering · Materials Science · Physics and Astronomy · #Advanced Materials and Mechanics #Buckling #Buoyancy #Compression (physics) #Drop (telecommunication) #Fluid Dynamics and Thin Films #Pickering emulsions and particle stabilization #Rotational symmetry #Surface tension #Thin film #Wrinkle #cond-mat.soft
paper · pdf · doi:10.1039/c6sm00945j
published as Soft Matter 12, 9289 (2016) · 16 pages, including Supplementary Information. Approximately the published version
openalex publication_date 2016/01/01 · openalex created_date 2016/09/23 · arxiv created 2020/08/10 · arxiv updated 2020/08/11 · openalex updated_date 2026/08/05
We study the effect of film density on the uniaxial compression of thin elastic films at a liquid-fluid interface. Using a combination of experiments and theory, we show that dense films first wrinkle and then fold as the compression is increased, similarly to what has been reported when the film density is neglected. However, we highlight the changes in the shape of the fold induced by the film's own weight and extend the model of Diamant and Witten [Phys. Rev. Lett., 2011, 107, 164302] to understand these changes. In particular, we suggest that it is the weight of the film that breaks the up-down symmetry apparent from previous models, but elusive experimentally. We then compress the film beyond the point of self-contact and observe a new behaviour dependent on the film density: the single fold that forms after wrinkling transitions into a closed loop after self-contact, encapsulating a cylindrical droplet of the upper fluid. The encapsulated drop either causes the loop to bend upward or to sink deeper as the compression is increased, depending on the relative buoyancy of the drop-film combination. We propose a model to qualitatively explain this behaviour. Finally, we discuss the relevance of the different buckling modes predicted in previous theoretical studies and highlight the important role of surface tension in the shape of the fold that is observed from the side-an aspect that is usually neglected in theoretical analyses.