Preparation of super-hydrophobic micro-needle CuO surface as a barrier against marine atmospheric corrosion

A super-hydrophobic (SH) CuO surface was prepared on copper using chemical etching followed by fluorination treatment. The relationship between surface morphology and hydrophobicity was investigated. When the etching time varied from 5 to 120 min, morphology changed from sparse sharp needles to dense sharp needles, and then to a stamen-like structure with flower-like dusters. All these surfaces were SH with the dense micro needle surface (10 min etching) the best. This SH surface made salt (NaCl) particles deliquesce and roll away. Electrochemical tests showed that it reduced corrosion in a 3.5% (w/w) NaCl solution by more than 10(2) times.