Compositional, structural and optical changes of polyimide irradiated by heavy ions

Abstract

Polyimide (PI, (C22H10O5N2)n) foil, 8 µm thick, was irradiated with 9.6‐MeV C4+ and O4+ ions at fluences of 1010–1013 cm−2. Compositional and structural changes related to the ion species, ion irradiation fluence and the type of polymer were studied and discussed in connection with energy‐loss measurement. The knowledge of these changes of polymers after the irradiation is very important for the estimation of the influence of these effects on the experimentally determined ion‐energy losses. Rutherford back‐scattering (RBS) and elastic recoil detection analysis (ERDA) were used for the elemental composition study, atomic force microscopy (AFM) for the detection of the changes in surface roughness and UV–Visible spectral study (UV–Vis) for variation in the absorbance and the optical band gap. The chemical and structural changes, new radical appearance, and polymeric chain crosslinking especially at ion fluencies above 1013 cm−2 were observed and discussed in the frame of energy stopping experimental determination. Copyright © 2016 John Wiley & Sons, Ltd.