Superhydrophobic aluminum surfaces by mechanical/chemical combined method and its corrosion behavior

In this paper, a combination of mechanical and chemical operation was used to fabricate superhydrophobic surfaces from aluminum by shot-peening, dislocation etching and immersing into the solutions of stearic, myristic, and decanoic acids. The key point in the combined method is using dislocation etching and also forest dislocations created by dislocations, which dissolve locations of dislocations in the grains and make a hierarchical structure. Hydrophobic properties of the aluminum surface were investigated by drop contact test, SEM, surface roughness, FTIR and AFM. A new test about bouncing and the time that drop contact with surfaces were measured. The corrosion resistance properties of surface-modified samples were studied by potentiodynamic polarization and EIS. Results show that metal surfaces etched by stearic acid, due to the low surface energy show superhydrophobic properties with contact angle about 157 degrees and a low adhesion for 8 mu L drops, vertical bar Z vertical bar (0.01) (Hz) parameter is approximately equal to 37,000 Omega cm(2). Because of the desirable properties obtained from the mentioned combined method, as well as its low cost, this method is expected to be vastly used for creating superhydrophobic surfaces in industry. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.