Fabrication of a robust superhydrophobic coating
Artificial superhydrophobic coatings inspired by nature are expected to have extensive applications in several aspects of our daily lives once their poor mechanical and chemical durability is overcome. In a new study, researchers have developed a robust superhydrophobic organic-inorganic hybrid coating through the combination of fluorinated ethylene propylene (FEP) and aluminum dihydrogen phosphate (ADP) using a novel two-step phase separation method.
An inorganic adhesive of ADP was introduced as a building block to enhance the structural robustness of the superhydrophobic coating. Carboxylated carbon nanotubes (C-CNTs) with good dispersibility in both water and ethanol were employed as emulsifiers to promote the liquid phase separation of FEP and ADP, which was beneficial for the formation of abundant microspheres in aqueous ethanol. After spraying and thermal treatment, the uniform mastoid micro-/nanostructures were formed on the coating surface due to the thermal phase separation of microspheres, which can provide excellent superhydrophobicity with a water contact angle of 162 ± 1.1° and a sliding angle of 5 ± 0.5°.
The prepared coating could maintain its outstanding hydrophobicity even after 1000 abrasion cycles with sandpaper and upon jetting with high pressure water flow (200 kPa). Moreover, owing to the chemical inertness of the hybrid micro-/nanostructures, the prepared coating could provide a high level of corrosion protection against strong corrosive mediums as well as weather protection against UV radiation.
The study has been published in Progress in Organic Coatings, Volume 157, August 2021.