Figure 2
How morphology, surface elements and wettability changed when 10–30 V etching voltages were applied. SEM images of dimples that were electrochemically etched at 10 V for (a) 4, (b) 8, (c) 12 and (d) 16 minutes, respectively. EDS spectrums of (e) superhydrophobic area without second etching and (f) the second etched dimple area. (g) CAs of 5 μL water droplets in the dimples etched at 10 V for different times. SEM images of dimples that were electrochemically etched at 20 V for (h) 3, (j) 5 and (l) 8 minutes, respectively. (i) Magnified SEM image of the boundary between the unetched isolated area and the etched area in (h). (k) Magnified SEM image of the unetched isolated area in (j). (m) Magnified SEM image of the bulged area in (l). (n) CAs of 5 μL water droplets in the dimples etched at 20 V for different times. SEM images and magnified SEM images of dimples that were electrochemically etched for 30 V at (o,p) 1, (q,r) 2 and (s,t) 3 minutes, respectively. (u) CAs of 5 μL water droplets in the dimples etched at 30 V for different times.
