The roughening process, surface modifier, amount of modifier, roughness, WCA, and CAH of the specimens.

SEM image of 1 M NaOH treated aluminium alloy surface that creates cone-like structure over the aluminum surface. The inset shows a closer look of a typically treated aluminum alloy surface.

SEM images of  the aluminum alloy surfaces etched for (a) 5 min and (b) 7 min in acid solution with volume ratio of V(H2O): V(HCl) : V(CH3COOH) = 20 : 8 : 1. The insets show a closer look of the etched aluminum alloy surfaces.

The EDS spectrum of (a) 7 min acid solution etched and (b) 7 min acid solution etched and cholosilane modified specimens. 

The WCA and CAH of (a) S71, (b) S73, and (c) S74 specimens.

Dynamic droplet/surface interaction on the surface of S71 specimen. Time between frames is about 25 milliseconds.

The rolling droplet on the surface of S71 specimen which is tilted 2.65°. Each consecutive image (a–f) was taken at 50 milliseconds interval.

The WCA of S71 specimen held at different temperatures. The insets show the water droplets on the surfaces after heating at different temperatures for 20 minutes.

Graphical Abstract