Effect of surface microstructure on the hydrophobicity of coatings

In this paper, coatings adopted SiO2 nanoparticles ranging from 1 wt% to 7 wt% were in situ polymerized with low surface energy polymer, and different surface microstructures were built automatically during painting film. Copper microstructure surface was also achieved by chemical etching method and then was modified by low surface energy resin as contrast. The contact angle and the peel strength between the coating and bio-gooey simulacrum were studied. The results showed that the hydrophobicity of the coating was remarkably affected by the surface microstructure. The coating containing 5 wt% SiO2 nanoparticles was covered with micro- and nano-scale salience and holes, and had the maximum contact angle and the minimum peel strength. Copper slices presented uniform micron and sub-micron structure surface when etching for 15 min and the contact angle reached a maximum of 125° after being modified.

► We build coating microstructures by SiO2 nanoparticles filling and chemical etching.
► Surface microstructure affects the hydrophobicity of the coating remarkably.
► Peel strength of bio-gooey can characterize the hydrophobicity of coating.