Facile fabrication of superhydrophobic silica coatings with excellent corrosion resistance and liquid marbles

Self-cleaning superhydrophobic coatings with water contact angle as high as 156 degrees and sliding angle as low as 3 degrees were prepared through a facile one-step spray coating process by spraying the hydrophobic silica nanoparticles onto Al substrate. In addition, the superhydrophobic coatings maintained excellent electrochemical corrosion resistance in a 3.5 wt% NaCl aqueous solution. The corrosion behavior of the superhydrophobic coatings on the Al substrate was characterized by the polarization curve and electrochemical impedance spectroscopy. The results indicated that the superhydrophobic coatings possessed excellent corrosion resistance. In addition, liquid marbles coated with hydrophobic silica nanoparticles were prepared by gentle rolling of liquid on powder beds of hydrophobic silica nanoparticles. Furthermore, water evaporation from the silica shell with time evolution was investigated using a contact angle measurement system video camera. Superhydrophobic silica surface with excellent corrosion resistance and liquid marbles coated with hydrophobic silica were fabricated by a facile process.