Fig. 4: Application of the proposed methodology to predict corrosion resistance of Al samples.
From: Predicting plastron thermodynamic stability for underwater superhydrophobicity
a Scanning electron microscopy images of the E-Al/FS (a1) and EA-Al/FS (a2) samples. b Energy-dispersive X-ray spectroscopy (EDS) measurements of the bare, E-Al/FS, and EA-Al/FS samples. c Optical reflectance microscopy image of the E-Al/FS (c1) and EA-Al/FS (c2) samples immersed underwater to assess air plastron shape and surface coverage. Inset images are the apparent water CA measured on the E-Al/FS and EA-Al/FS surfaces. d 3D reconstruction AFM image of EA-Al/FS. e Lafuma and Quéré diagram demonstrates the stability of the Cassie–Baxter wetting regime on the EA-Al/FS samples. f Marmur diagram calculated for bare and EA-Al/FS samples using the solid–liquid area fraction values as shown in (c). g–h Digital images showing the bare Al (g) and EA-Al/FS (h) samples were recorded on day 0 and on day 234 of immersion in artificial seawater. The bottom images were captured at a grazing angle to prove the existence of plastron on the EA-Al/FS samples by their high reflectivity, in contrast to the bare Al samples that were severely corroded. The most stable, advancing and receding CAs and dimensionless roughness parameter were measured on N = 3 independent samples, while the data represent the measured average value and the s.d.
