Spectroscopic analysis of 1.75 MeV N5+ ions irradiated polystyrene film and the quest for the reaction mechanisms of fullerene and other products

The effects of 1.75 MeV N5+ ion beams of varying fluences, ranging from 1 x 10(11) to 1 x 10(14) ions/cm(2), have been used to investigate the structural, optical, and chemical properties of polystyrene using X-ray diffraction (XRD), UV-Visible spectroscopic, and Fourier transform infrared (FTIR) spectroscopic techniques. The changes in polystyrene polymer depend on ion fluence. The crystallinity has been increased drastically up to the ion fluence of 5 x 10(12) ions/cm(2), and decreases further up to 1 x 10(14) ions/cm(2). The energy of the direct bandgap is found to be reduced by up to 50% when compared to the pristine one. The shift in absorption maxima towards a higher wavelength supports color development in polymer films and is due to the formation of extended conjugation. The developments of FTIR peaks at 1601, 1697, 3321, and 3723 cm(-1) support the existence of aromatic rings, carbonyl (>C=O), acetylenic (-C equivalent to C-), and hydroxyl functional groups in the irradiated polystyrene. Functional group generation is exponentially dependent on the quantity of ion fluences. The reaction mechanism of degradation products formation chemistry has been discussed.