Morphology Correlation To the Superhydrophobicity in AN Organic Thin Film on Rough Al

A novel superhydrophobic ultra-thin film with contact angle of 166degrees was prepared by stearic acid (STA) chemically adsorbed onto the polyethyleneimine (PEI) coated aluminum wafer. Composite interface between the water droplet and the rough needle-like surface was attributed to responsible for the super water-repellent property. It was found that close relationship existed between the surface morphology and the contact angle. The ultra-thin film has weak contact angle hysteresis with the advancing and receding contact angle about 168degrees and 156degrees, respectively. However, if the water droplet was placed onto the surface keeping static for a long times, the contact mode might be changed from composite interface into noncomposite interface, and then generate large angle hysteresis