Fabrication of Superhydrophobic Surface on Aluminum Substrate

The authors develop a simple and economic method to fabricate the superhydrophobic surface by means of electrochemical machining. The fabrication mechanism is based on the fact that the grain boundaries/dislocations are micro/nano-scale and more likely to be anodic dissolved than that of grain self; so the multi-scale micro/nano-structures surface can be generated by an applied electric field and the chemical solution. The relationship of processing quality, efficiency and conditions is studied in experiments in this paper. The results show that electrochemical processing can be used to fabricate dual-scale micro/nano-structures on aluminum surfaces, and further applying to generate the large size of superhydrophobic surface. The method is easier to control the reaction process than chemical etching meanwhile more economical than other techniques. After modified with low surface energy materials, the surface exhibits superhydrophobic property with water contact angle of 1600 and tilt angle less than 5 degrees.