Study of stability in gamma irradiation of luminescent film of PMMA with Eu(3+)/AG nanoparticles

Abstract

Lanthanides, which are part of rare earths, have attracted attention due to their optical properties not only in research field, but also, in industrial and technological areas. Eu3+ ions are among the most studied of the rare earth complexes because they present higher luminescence, due to the structures of their energy levels. The combination with ligands of high molar absorptivity can promote a higher emission of the rare earth ions. The luminescent polymer system used as markers was obtained from doping with rare earth complexes, incorporating a Europium complex containing tenoyltrifluoroacetonate (TTA) and triphenylphosphine oxide (TPPO) anion in the process of encapsulating silver nanoparticles in methyl polymethacrylate (PMMA). The luminescent and thermal properties of the material were analyzed in the luminescent films before and after exposure to ionizing radiation in a 60Co source at doses of 10, 30 and 50 kGy. The TTA ligand undergoes decay of the luminescence when the precursor complex is exposed to ionizing radiation. Once doped in the PMMA polymer matrix it will be possible to protect stabilizing the luminescence of the complex. The study of the luminescence properties was performed by the spectrofluorimetry technique. The thermal properties and the decomposition profile of the material were obtained by the Thermogravimetric Analysis (TGA / DTG) in N2 atmosphere. To investigate the enthalpic variations of the samples, the Differential Exploration Calorimetry (DSC) technique was used in N2 atmosphere.