Hydrophobic carbonaceous materials obtained by covalent bonding of perfluorocarbon and perfluoropolyether chains

Abstract

Perfluorocarbon residues, i.e. perfluoroethyl (PFE), CF₃CF₂–, perfluoro-n-propyl (PFnP), CF₃CF₂CF₂–, perfluoro-isopropyl (PFiP), (CF₃)₂CF–, and perfluoropolyether (PFPE) chains, e.g. (CF₂CF₂O)_m(CF₂O)_n, were covalently bonded on the surface of carbon black (CB) and diamond-like carbon (DLC) using PFPE and perfluorodiacyl (PFDA) peroxides. The thermal decomposition of the peroxidic moieties of these perfluorinated peroxides generated reactive perfluorinated radicals. The perfluorinated free radicals could directly bond to the sp² sites avoiding any spacer, which usually decreases both thermal and chemical stabilities of the resulting materials. The effects of chemical treatment on the carbonaceous materials were studied using X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Contact Angle (CA) measurements. The surface areas of CB powders were determined by the BET technique; the morphology of the DLC coatings was evaluated by Atomic Force Microscopy (AFM) and the friction forces were measured by means of Lateral Force Microscopy (LFM).