Fig. 4: Freezing on superhydrophobic surfaces at ambient pressure.
From: Freezing-induced wetting transitions on superhydrophobic surfaces
a,b, Synchronized side- (a) and bottom- (b) view image sequences of a water droplet freezing in a cold, dry environment at atmospheric pressure (red circles mark the approximate location of the contact line post-recalescence) on a superhydrophobic PDMS texture [d, s, h] = [10, 50, 40] µm (identifier D2 in Supplementary Table 1). c, Enlarged view between the pillars underneath the droplet for each timestep (for the regions of interest marked in b). d, Schematic of the bottom-up suffusion mechanism responsible for surface failure from condensation filling, coalescence (black arrow) and freezing. Water, ice slush and solid ice are represented by blue shading, light blue shading and hatching, respectively. Scale bars: a, 1 mm; b, 300 µm; c, 100 µm. All experiments (N = 24) showed bottom-up suffusion. Employed surfaces: D2 and D5 with pillar heights of 25 and 40 μm (n = 6) (see Supplementary Table 1 for details).
