Advantage of Super-hydrophobic Surface as a Barrier against Atmospheric Corrosion Induced by Salt Deliquescence

This study demonstrates the advantage of using super-hydrophobic surface as a barrier against atmospheric corrosion induced by salt deliquescence. Different from the behaviour on hydrophilic and hydrophobic surfaces, deliquesced NaCl particle slips off super-hydrophobic surface inclined at an angle of similar to 20 degrees, thereby preventing corrosion of underlying substrate by deliquesced salt. The observed slipping behaviour could be attributed to lubrication action of saline solution between deliquesced NaCl particle and super-hydrophobic film, as well as weak attraction between saline solution and substrate. Electrochemical measurements prove that the existence of air film contributes to the enhancement of barrier performance of super-hydrophobic film. (C) 2014 Elsevier Ltd. All rights reserved.