XPS analysis of PTFE decomposition due to ionizing radiation

Autor: W. Schnurnberger, Erich Gülzow, Klaus Bolwin, Mathias Schulze
Rok vydání: 1995
Předmět:
Zdroj: Fresenius' Journal of Analytical Chemistry. 353:778-784
ISSN: 1618-2650
0937-0633
Popis: X-ray induced photoelectron spectroscopy (XPS) in combination with depth profiling has been used to investigate the structure and the degradation mechanism of PTFE bonded gas diffusion electrodes (GDE). The XP-spectra of these electrodes show distinctly separated binding states of the C1s electrons at Eb=292 eV and Eb=286 eV. These binding states are related to the carbon in the (CF2)n configuration (C1sCF2) and the graphite (C1sgraphite), respectively. The C1sCF2 signal decreases are induced by both X-ray exposure and ion etching. Simultaneously a decrease of the F1s signal has been approved. The intensity ratio of F1s to C1sCF2 has increased during the experiment. These results indicate a decomposition of PTFE which creates CF fractions, leading to an excess intensity in the energetic range between the C1s binding states of the PTFE and the graphite. Although both the F1s and the C1s spectra are strongly modified by ionizing radiation, samples are comparable, when exposition doses are equal.
Databáze: OpenAIRE
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