PHOTODEGRADATION OF POLY(TETRAFLUOROETHYLENE) AND POLY(VINYLIDENE FLUORIDE) THIN FILMS BY INNER SHELL EXCITATION

Abstract

Ion time-of-flight (TOF) mass spectra of poly(tetrafluoroethylene) (PTFE) and poly(vinylidene fluoride) (PVDF) thin films near fluorine and carbon K-edges were observed. For PTFE thin films, peaks corresponding to F +, CF +, and [Formula: see text] appeared, while for PVDF F + and H + were mainly observed. They indicate that for PTFE the polymer chain (C–C bonds) as well as C–F bonds are broken by irradiation of photons near fluorine and carbon K-edges, while for PVDF the bond scission occurs mainly at the C–F and C–H bond. Partial ion yields (PIY) of these ions for PTFE and PVDF thin films show strong photon energy dependencies near fluorine and carbon K-edges. The excitation from fluorine 1s to σ( C – F )* is specially efficient for F + ion production for both PTFE and PVDF.