Reducing the photo-bleaching effect of a new europium complex embedded in styrene butadiene copolymer

Abstract A highly luminescent europium complex obtained with two different ligands, succinimide ( S I ) and 2-thenoyltrifluoroacetone ( T T A ) , was synthetized with different TTA concentrations. The photoluminescence (PL) emission from these materials corresponds to the characteristic inter-electronic energy level transitions of the Eu3+ ions. However, the excitation spectrum is strongly dependent on the presence of TTA, having an optimum response when 0.75 mmol of this compound is added to the E u L 3 ( H 2 O ) 3 complex. The quantum yield obtained by these powders were around 72 % ± 1.7 % indicating an optimum sensitization of these complex. The E u L 3 T T A complex with the best PL properties was embedded in a styrene butadiene copolymer (SBC) film, produced by the drop casting method, obtaining similar PL behavior at different concentrations, the highest intensity was observed at 1.2% (w/v) of E u L 3 T T A complex and the quantum yield of these composite films was 60.5 % ± 2 % . These films were exposed to continuous UV irradiation and after 141 h no photo-bleaching effect was observed in contrast with the E u L 3 T T A complex that exhibited a noticeable photoluminescence intensity degradation at much shorter exposure times. Both the Eu-complexes and the composite films were characterized by FT-IR, XRD, SEM and fluorescence spectroscopy.