Hydrophobic and super-hydrophobic coatings based on nanoparticles overcoated by fluorocarbon plasma polymer

• We present new method for deposition of highly hydrophobic surfaces.
• Proposed process is fully vacuum-based, time and cost effective.
• The roughness of prepared samples may be adjusted by the size of used nanoparticles.
• Superhydrophobic and slippery coatings were produced at higher values of roughness.

This study proposes preparation of highly hydrophobic and super-hydrophobic fluorocarbon surfaces using a simple fully vacuum-based method. The method combines deposition of nanoparticle films by means of gas aggregation sources and overcoating of such films by a magnetron sputtered polytetrafluoroethylene layer. This makes it possible to vary independently the roughness of the resulting surfaces and their chemical composition. The surface roughness is given by the underlying nanoparticle film and surface chemical composition by the chemical structure of the thin film overcoat. It is demonstrated that the surface roughness, i.e. a key parameter that governs wettability, may be adjusted by the size of nanoparticles used in a relatively wide range. Finally, it is shown that at certain surface roughness, 60 nm in this study, the fabricated surfaces become super-hydrophobic and slippery.