Erosion Study of Poly(ethylene tetrafluoroethylene) (Tefzel) by Hyperthermal Atomic Oxygen

This is the authors' abstract. We don't add key points for this paper.

In this study the erosion of poly(ethylene tetrafluoroethylene) (ETFE) (Tefzel) by hyperthermal atomic oxygen (AO) has been examined using X-ray photoelectron spectroscopy (XPS). Initially, the Tefzel film had F/C and O/C atom ratios of 0.74 and 0.04, which decrease to 0.17 and 0.01, respectively, after a 2 h exposure to a flux of 2 × 10 15 atoms/(cm 2 s) AO with an average kinetic energy of 5 eV. The F/C atom ratio is further reduced to 0.02 with longer AO exposures, essentially producing a graphitic or amorphous carbon-like layer with a carbon content greater than 90 at. %. Longer AO exposures do not alter the composition of this layer significantly. Exposure of the AO-damaged surface to O 2 or air nearly doubles the oxygen content in the near-surface region. This is due to dissociative oxygen adsorption at reactive sites formed at the polymer surface during AO exposure. Further exposure to AO removes this chemisorbed oxygen. C−H bonds are important sites for attack during erosion by hyperthermal AO.