Effects of neutron–gamma radiation on the free radical contents in epoxy resin: upconversion luminescence and structural stabilization

Abstract

The purpose of this work is to study the effect of mixed neutron–gamma radiation (MNGR) on structural, optical and paramagnetic properties on epoxy resin nanostructure thin films [ER]NSTF. These films were prepared and irradiated in the nuclear reactor with dose range between 100 and 900 Gy. After exposure to MNGR, FT-IR results demonstrated the broad ν(OH) and ν(C=O) band to increase with increase in radiation dose, while the ν(C–H) band decreased with increase in radiation dose. This is due to the formation of chain stretch, bending and scission/cross-linking through MNGR that lead to a decrease in the crystallinity region contained within the [ER]NSTF. XRD data confirm these results and show that the crystalline phase was destroyed by MNGR irradiation. PL is used to determine the fundamental transition and defects transitions in [ER]NSTF at 300 K. It was found that MNGR leads to significant enhancement of the luminescence properties. Samples of [ER]NSTF irradiated with 600 Gy dose presented the highest response. Therefore, EPR results confirmed that MNGR induces the paramagnetic center’s formation of the [ER]NSTF whose concentration varies differently.