Chemical treatments can be used to render metals hydrophobic, causing water to bead on the surface rather than spreading to wet it. Treating the surface by immersing it in boiling water before applying the chemicals creates a nanoscale texture that accentuates the hydrophobicity. Even on a common metal like aluminum, this combination of texturing and chemical treatment leads to superhydrophobic behavior. Here the technique is demonstrated by spraying water droplets on a piece of treated aluminum. (Video credit: B. Rosenberg et al.; submitted by D. Quinn)
Making Metal Water-Repellent
