Investigations into the chemistry of perfluorodiethoxymethane at nickel and nickel oxide surfaces

We describe the surface chemistry of a Iow -moieeuiar-weight perfluoroether with an acetal (-0-CF₂~0-) unit. The acetal unit has been proposed by others as the critical moiety responsible for the decomposition of linear perfluoropolyethers at metal surfaces. Three nickel surfaces are studied, clean Ni(100), Ni(100) c(2X2)-G, and NiO(lOO). The experimental techniques are temperature-programmed desorption and high-resolution electron energy loss spectroscopy. Our work shows that even when a perfluoroether containing an acetal unit is used, in this case perfluorodiethoxymethane, decomposition is not apparent on any of the surfaces studied under typical ultrahigh vacuum conditions.