Electronic energy transfer effects of Ti9+ and S9+ ions irradiations upon structural, optical and chemical properties of Kapton-H polymer

The exposure of polymeric materials to high energy ions increases their applicability in numerous fields by altering certain properties. The electronic energy loss (Se) of swift heavy ions (SHI) is the most responsible parameter for the change of properties of a material under exposure. The value of Se increases as the atomic number (Z) of the impinging ions upon the target sample is increased. The current research enlightens the structural, optical and chemical modifications in Kapton-H polyimide polymer due to S9+ (Z = 16) and Ti9+ (Z = 22) ions (each of energy 120 MeV) irradiations in the fluence range of 5 × 1010 to 5 × 1012 ions/cm2. In the results, the polymer amorphization was observed in the X-ray diffraction (XRD) studies whereas UV visible (UV-Vis) spectroscopy showed shift in the absorption peak thereby decreasing the band gap energy up to 12.4% as per Tauc's relation calculations. In addition to these results, certain modifications in prominent bands such as C= O carbonyl symmetric stretching and OH stretching were observed in Fourier transform infrared (FTIR) spectroscopy. The crystallite size was observed to be modified in XRD study. The photoluminescence studies revealed that the intensity peaks of irradiated samples decreased at lower fluences, however the opposite behaviour was observed at higher fluences in both cases of irradiations.