Perfluoropolyether-based organic-inorganic hybrid coatings: Preparation and surface characterisation

Hydrophobic-oleophobic coatings were prepared by using the sol-gel process with organic-inorganic hybrids based on perfluoropolyether-polycaprolactone (PFPE-PCL) copolymers. Hybrid coatings were prepared by changing the organic-inorganic ratio, the PFPE/PCL ratio in the copolymer, and the reaction conditions. A complete surface characterisation was carried out by contact angle analysis and x-ray photoemission spectroscopy (XPS). In all cases the wettability of the coatings was found to be very low. Surface composition analysis showed that the surface segregation of the fluorinated PFPE segments was always high enough to give a very high hydrophobic character to the coating surface.