Journal of Applied Polymer Science, Vol.83, No.12, 2716-2726, 2002
Enhancement of the luminescent intensity of the novel system containing Eu3+-beta-diketonate complex doped in the epoxy resin
Photoluminescent properties of the europium tris(thenoyltrifluoroacetonate) dihydrate [Eu(TTA)(3)(H2O)(2)] incorporated in epoxy resin in the solid state are reported. The polymeric Eu3+ complex and the precursor compound were characterized by elemental analysis, thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy, nuclear magnetic resonance (NMR), and electronic spectroscopy. Due to efficient energy transfer from the polymer to the rare earth ion, the polymer phosphorescence intensity was observed to decrease with an increase of the Eu3+ ion concentration. High values of the Omega(2) intensity parameter were obtained, reflecting the hypersensitive character of the (5)Do --> F-7(2) transition and indicating that the Eu3+ ions are in a highly polarizable chemical environment. This is consistent with systems containing epoxy resin that generally show a higher value for the 0, parameter as a consequence of the difference in the basicity of the oxygen donor from the polymer. Lifetime measurement (T = 0.442 ms) suggests that the Eu` luminescence has a higher efficiency than in the case of hydrated compound (tau = 0.260 ms). The emission quantum efficiency shows higher luminescence for the polymer containing 1% of EU3+- beta-diketonate complex.