Douglas A. Olsen

Modification of metal surfaces with difluorocarbene and heptyl nitrene

Abstract Difluorocarbene and heptyl nitrene have been shown to irreversibly modify the surfaces of several metals as established by wettability measurements. The critical surface tension values thus obtained are shown to have a strong dependence upon the atomic radius of the underlying metal substrate. Several possible surface structures are discussed; however, the results suggest bonding between the difluorocarbene (or heptylnitrene) biradical and the metal substrate.

Diffusional kinetics of difluorocarbene

Abstract The generation of difluorocarbene from sodium chlorodifluoroacetate and its subsequent reaction with metal surfaces involves a complex set of reactions. As shown here it is possible to evaluate an effective diffusion constant incorporating several rate and diffusion constants. The procedure used was to determine the degree of reaction of the difluorocarbene on stainless steel surfaces. Extrapolation back to the onset of the surface reaction gave the time required for diffusion. Since the diffusion distance was known, the diffusion constant could be calculated. The results are also shown to be consistent with equations derived from Ficks laws.

Surface reactions of carbenes and nitrenes on stainless steel

Abstract Three substituted carbenes, nitrene, and two substituted nitrenes generated by pyrolysis of the appropriate precursors are shown to irreversibly modify the surface of stainless steel. Critical surface tension values obtained from wettability measurements are used to establish the presence of the various reacted species on the stainless steel surface. The infrared frustrated multiple internal reflection spectrum of the difluorocarbene modified stainless steel surface is used to establish that a sigma-diadsorbed-olefin complex may be formed on the metal surface.