Superhydrophobic fluoropolymer-modified copper surface via surface graft polymerisation for corrosion protection

With the objective of developing materials with repellent surfaces by combining both low surface energy and rough structure, superhydrophobic fluoropolymer films were prepared via surface graft polymerisation from copper substrates. A vinyl-terminated trimethoxysilane was firstly immobilised on the etched-copper surface to introduce active carbon–carbon double bonds. Subsequent graft polymerisation of 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), in the presence of a polymerisation initiator 4,4′-azobis-(4-cyanpentanoic acid), yielded the fluoropolymer films on the copper substrates. The resultant P(HFBA)-grafted surfaces not only exhibited desired superhydrophobic property with water contact angle above 150°, but substantially improved the corrosion resistance of copper substrates.

The representative SEM images of (a) etched Cu and (b) Cu-g-P(HFBA)2 surfaces, and the insets are contact angle profiles of water droplet on the corresponding etched Cu and Cu-g-P(HFBA)2 surfaces.Figure optionsDownload as PowerPoint slideHighlights
► Fabrication of superhydrophobic films on copper via surface graft polymerisation.
► The superhydrophobicity arising from surface compositions and microstructures.
► The substantially-enhanced corrosion resistance of the grafted fluoropolymer films.
► The gradual change of superhydrophobicity with immersion time.