Surface chemical changes of polytetrafluoroethylene under sub-keV (10–500 eV) electron irradiation: An X-ray photoelectron spectroscopy analysis
Year: 2026
Type: article
Abstract: Per- and polyfluoroalkyl substances (PFAS) are a significant environmental concern because of their extreme persistence. High-energy (keV-MeV) irradiation has the potential to cause complete PFAS decomposition; however, the surface chemical changes induced by sub-keV remain poorly understood. In this study, we investigated sub-keV (10-500 eV) electron-induced surface chemical changes in polytetrafluoroethylene (PTFE, CnF2n), the simplest solid PFAS polymer, using X-ray photoelectron spectroscopy (XPS). At 500 eV, electron irradiation induced extensive ionization-driven reactions within the surface region, resulting in pronounced defluorination and backbone rearrangements of the polymer chains. The CF₂ component decreases while CF₃, C–F, and C–CF species sequentially emerge, and the fluorine-to-carbon(F/C) ratio declines from 1.9 to 0.6 after 4 h of irradiation. At 70 eV, ionization-driven surface degradation of PTFE was milder than that observed at 500 eV. Even at 10 eV, irradiation induced both ionization and dissociative electron attachment (DEA), making its efficiency higher than that of 70 eV irradiation. These results provide direct experimental evidence that clarifies the role of sub-keV electrons in PFAS degradation, indicating the potential for using sub-keV electrons for controlled surface modifications.
Source: Applied Surface Science
Authors: Hao Yu, Jackson King, Sylwia Ptasińska
Institution: University of Notre Dame
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,930
Award: G444357326
OpenAlex ID: W7124989471