Swift heavy ion induced modifications of luminescence and mechanical properties of polypropylene/ZnO nanocomposites

The effect of irradiation with 150 MeV Kr ions at fluencies 1011 and 1012 ions/cm2 on luminescence of PP/ZnO nanocomposites and PP matrix has been studied. In unirradiated composite the luminescence is comparatively weak and is contributed mainly by the excitonic luminescence of ZnO. Irradiation of nanocomposite and PP matrix leads to a strong increase of luminescence intensity in a wide spectral range of 360-600 nm. It follows from the obtained results that the enhancement of luminescence originates mainly from the broken bonds in PP matrix. Ion-induced scission of polymer bonds and fragmentation of polymer chains is deduced also from the nanoindentation tests which show a remarkable reduction of hardness for the irradiated samples.