Preparation of Nano-structure Superhydrophobic Surfaces on Aluminum Alloy by Simple Immersion Chemical Etching Method

In the present research, a novel simple cost-effective powerless method for fabrication of micro-nano structured superhydrophobic surface on aluminum alloy has been suggested. A contact angle of 167.1 º was measured for water drop on superhydrophobic surface. Micro-nano roughness feature was observed by SEM images on the surface and chemical analysis of the surface revealed by EDS and showed the presence of carbon chains on the surface. The effect of etching time on water contact angle value was investigated and the optimum etching time of 4 min was reported. It was estimated that 97% of surface are contacted with air in aqueous solution. Potentiodynamic polarization test showed that the corrosion current density has been decreased on superhydrophobic surface from 1.4 to 0.7 µA/cm2 in compared with normal polished Al alloy surface. This indicates that the alloy lifetime has been increased two folds. Furthermore, self-cleaning character and repulsion capability of the surface against various common liquids was investigated experimentally.