Linear and branched perfluoropolyether coatings on diamond-like carbon films: covalent linkage and physical deposition

The progresses in the magnetic media technology brought to the application of liquid lubricant films on diamond-like carbon (DLC) coatings. Hard surfaces are typically lubricated with fluorinated or perfluorinated organic compounds, such as perfluoropolyethers (PFPE) (1). Many attempts have been done to obtain a stable layer of PFPE lubricant on the DLC surface by dip-coating or by vapour deposition so as to minimize any friction and wear (2, 3). Diamond-like carbons are formed by an amorphous mixture of sp3 and sp2 hybridized carbon atoms with hydrogen atoms incorporated in the structure (a-C:H DLC). We have established a specific methodology for the straight-forward introduction of perfluorinated groups with carbon-carbon bond formation on a variety of unsaturated materials (4-8)