Fig. 3: Top-view snapshots of oil spreading on the cavity surface during bubble bursting at the aqueous surface.
From: Compound jetting from bubble bursting at an air-oil-water interface
The water surfaces shown here are (a) clean, and covered by a layer of (b) 100 cSt silicone oil, h/R = 0.8, (c) 1000 cSt silicone oil, h/R = 0.8, and (d) 1000 cSt silicone oil, h/R = 1.2. Scale bar = 1 mm. Comparing with the pure water case (a), a macroscopic oil edge (marked by red arrows) along the cavity after the cap rupture at an oil-covered aqueous surface is clearly observed, which is generated by oil spreading in the complete-wetting state (b–d). The macroscopic oil edges can be distinguished since they typically show asymmetric and irregular morphology, while the capillary waves from cavity collapse show axisymmetric and smooth patterns. Additional evidence is shown in Supplementary Fig. 5 with tracer particles to assist visualization of the macroscopic oil edges.
