2019/08/21 by José Graña Otero, Otero, José Graña, Ignacio E. Parra Fabián +1
Computer Science · Engineering · Materials Science · #Advanced Data Storage Technologies #Electrohydrodynamics and Fluid Dynamics #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Soft Condensed Matter (cond-mat.soft) #Surface Modification and Superhydrophobicity
paper · pdf · doi:10.48550/arxiv.1908.07971
openalex publication_date 2019/08/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Superhydrophobicity relies on the stability of drops's interfaces pinned on sharp edges to sustain non-wetting (Cassie-Baxter) equilibrium states. Gibbs already pointed out that equilibrium is possible as long as the pinning angle at the edge falls between the equilibrium contact angles corresponding to the flanks of the edge. However, the lack of stability can restrict further the realizable equilibrium configurations. To find these limits we analyze here the equilibrium and stability of two-dimensional drops bounded by interfaces pinned on mathematically sharp edges. We are specifically interested on how the drop's stability depends on its size, which is measured with the Bond number Bo = (Wd/ℓc)2, defined as the ratio of the drop's characteristic length scale Wd to the capillary length ℓc = √(σ/ρg). Drops with a fixed volume become more stable as they shrink in size. On the contrary, open drops, i.e. capable of exchanging mass with a reservoir, are less stable as their associated Bond number decreases.