Chemical modification of polycarbonate induced by 1.4 GeVAr ions

Polycarbonate foil stacks were irradiated with 1.4 GeV Ar ions at room temperature. The induced modifications in chemical structure were studied by Fourier transform infrared (FTIR) and ultraviolet/visible absorption (UV/VIS) spectroscopies. FTIR measurements reveal that material degradation through bond breaking are the main effects. Significant reduction in absorbance of the typical infrared bands is observed at energy densities higher than 8 x 10(22) eV/cm(3). Alkyne end groups are produced by the irradiations and the electronic energy loss threshold for production of the alkyne end group is found to be below 0.61 keV/nm. UV/VIS measurements indicate a shifting of the absorption edge from ultraviolet towards visible and a strong increase of absorbance in the ultraviolet and visible regions. The irradiation induced changes in absorbance at wavelengths of 384 450 and 500 nm follow roughly linear relationship with fluence and scale rather good with the square of electronic energy loss. The results are briefly discussed. (C) 2000 Elsevier Science B.V. All rights reserved.