Abstract-Chemical etching has been used to create nanostructured patterns on aluminum surfaces. The micro/nanostructure obtained of the surfaces has been examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The nanostructured patterns have been passivated using stearic acid and fluoroalkylsilane molecules to obtain low energy surfaces terminated with −CH3 and −CF3 groups, respectively. Optimized annealing temperatures have been obtained for both systems to achieve the highest contact angle and the lowest hysteresis. These surfaces are found to be highly superhydrophobic with a water contact angle higher than 170◦ with a very low hysteresis. However, −CF3 terminated surfaces show lower hysteresis as compared to −CH3 terminated surfaces.
Keywords: Chemical etching; nanostructured patterns; superhydrophobicity; contact angle; thermal desorption.