Super-hydrophobic surface on pure magnesium substrate by wet chemical method

A layer of flower-like super-hydrophobic film was fabricated on pure Mg surface by chemical etching in H2SO4, H2O2 and subsequent immersion in stearic acid (CH3(CH2)16COOH) ethanol solution. The super-hydrophobic surface showed a static water contact angle of 154° with the sliding angle of about 3°. With scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Fourier-transform infrared (FT-IR) spectrometer, the microstructure and composition of the sample were analyzed. Results showed that the flower-like structure and the bonding of the CH3(CH2)16COO− on Mg surface can be responsible for the superior water-repellent property. Electrochemical impedance spectroscopy revealed that the transfer resistance of super-hydrophobic surface was increased about four times than bare Mg after one-hour immersion in 0.1 mol/L NaCl solution.