Fig. 1: Non-rebound of an impinging hollow droplet.
From: Suppression of hollow droplet rebound on super-repellent surfaces
a, b Schematic of a single-phase droplet (SD) of radius R0 (a) and a hollow droplet of apparent radius R0 and bubble radius Rb (b), released from the initial height H0. c, d Snapshots of the SD (c) and HD (d) impacting a super-repellent surface released from a height of H0 = 0.9 mm. The SD takes off, whereas the HD rests on the surface after impact. e The plot of the droplet’s bottom height (Hb) versus time for the two events in (c) and (d). f Dependence of the contact time tc on bubble volume fraction Φ. Φ = 0 stands for SD while Φ > 0 for HD. In the case of the non-rebound HD, the contact time is set to be equal to the droplet’s complete evaporation time t*, which was approximately 7200 s in experiments. Insets, snapshots of a bouncing HD with Φ = 0.2 (left) and a resting HD with Φ = 0.8. The liquid surface tension is 53 mN m−1 in (c)–(f). Scale bars, 1 mm.
