A fast method to fabricate superhydrophobic surfaces on zinc substrate with ion assisted chemical etching

A metal assisted chemical etching process was proposed to rapidly fabricate super-hydrophobic surfaces on Zn substrates. The influence of three assisting metal ions (Ag+, Cr3+) on the morphology of the fabricated surfaces, and their hydrophobicity after modification by fluorosilane, were studied. This work indicates that the metal ions play an important role on the structure and the hydrophobicity of the prepared surfaces. The rough structure required for super-hydrophobic surfaces, with contact angles of 158 +/- 2 degrees and 161 +/- 2 degrees, respectively, can be easily obtained within 5s with Cu2+ or Ag+ assisted chemical etching process. The treatment conditions of Cu2+ assisted chemical etching method were optimized. The sample with the highest contact angle can be achieved when the concentration of Cu(NO3)(2) is 0.08 mol L-1, the concentration of HNO3 is 0.6 mol L-1, and the etching time is 5s at 30 degrees C. And the prepared superhydrophobic surfaces exhibited enough stability in the air. (C) 2014 Elsevier B.V. All rights reserved.