Abstract
In the past few years, the fabrication of fluorocarbon superhydrophobic surfaces has attracted considerable attention due to the great potential of such materials in a wide range of applications. As a consequence, various vacuum-based deposition methods were developed for achieving superhydrophobicity.
They are based either on etching of fluorocarbon surfaces, their self-nanostructuring during the deposition, or on two-step processes, where in the first step nano-rough surface is produced that is subsequently coated by a thin fluorocarbon film. In this study we introduce and compare three novel and alternative vacuum deposition techniques that may be utilized for fabrication of superhydrophobic coatings.
We employed (i) deposition on remote substrates by magnetron sputtering of PTFE targets, (ii) deposition of PTFE nanoparticles produced by means of a gas aggregation source and (iii) a two-step process combining the deposition of a nano-cluster film and its overcoating with magnetron sputtered PTFE. All prepared samples were characterized in terms of their chemical structure (XPS, FT-IR), morphology (SEM, AFM) and wettability.
It appeared that although the chemical composition and morphology of the coatings prepared by the above-mentioned techniques differ, all three tested methods are suitable for production of films that exhibit a superhydrophobic character.