INVESTIGATIONS INTO THE CHEMISTRY OF PERFLUORODIETHOXYMETHANE AT NICKEL AND NICKEL-OXIDE SURFACES

We describe the surface chemistry of a low-molecular-weight perfluoroe ther with an acetal (-O-CF2-O-) unit. The acetal unit has been propose d by others as the critical moiety responsible for the decomposition o f linear perfluoropolyethers at metal surfaces. Three nickel surfaces are studied, clean Ni(100), Ni(100) c(2X2)-O, and NiO(100). The experi mental techniques are temperature-programmed desorption and high-resol ution electron energy loss spectroscopy. Our work shows that even when a perfluoroether containing an acetal unit is used, in this case perf luorodiethoxymethane, decomposition is not apparent on any of the surf aces studied under typical ultrahigh vacuum conditions.