METALLIZATION OF TEFLON PFA .2. INTERACTIONS OF TI, AG, AND AU MEASURED BY X-RAY PHOTOELECTRON-SPECTROSCOPY

Ti, Ag, and Au were evaporated onto Teflon PFA (polytetrafluoroethylen e-co-perfluoroalkoxy vinyl ether) surfaces by electron beam evaporatio n. Au was also sputtered onto PFA, in order to examine the effect of t he kinetic energy of the depositing metal atoms on the metal/polymer i nteraction. The evolution of metal/polymer interfacial structures with increasing deposited metal thickness was followed using x-ray photoel ectron spectroscopy. It was found that Ti deposition leads to defluori nation and the formation of fluoride and carbide species. The reaction s increased with deposited Ti thickness, slowly in the initial stages of deposition but more rapidly afterwards. The effects of evaporated A g and Au were very similar, both resulting in slight losses of fluorin e: No formation of new species was detected. Compared to evaporated Au , sputtered Au increased polymer surface modification, indicated by th e formation of -CF3, -CF-, and -C- species; an enhanced chemical react ivity was manifested by die appearance of Au fluorides. After depositi on of the first several angstrom of metal, the rate of deposition onto the PFA was enhanced for evaporation but decreased for sputtering, du e to the action of subsequently sputtered species.