Synthesis and luminescence properties of novel Eu-containing copolymers consisting of Eu(III)-acrylate-beta-diketonate complex monomers and methyl methacrylate

Luminescent Eu-containing copolymers were synthesized through the copolymer ization of Eu-complex monomers containing beta-diketones with methyl methac rylate and characterized by FT-IR, UV-vis, XPS, GPC, TGA, and DSC. All thes e Eu copolymers are fully soluble in common organic solvents and can be cas t into transparent, uniform, thin films with good mechanical flexibility an d thermal stability. The Eu-copolymer luminophores exhibited intense red li ght at 615 nm under UV excitation at room temperature, which is attributed to the D-5(0)-->F-7(2) transition of Eu(III) ions. The luminescence intensi ties, lifetimes and monochromaticities, eta(D-5(0)-->F-7(2)/D-5(0)-->F-7(1) ), Of the Eu-copolymers are much higher than that of the corresponding Eu-c omplex monomers as well as Eu-complex/PMMA blends. Energy transfer processe s and microenvironment effects were found to contribute to the improvement of the luminescence properties of the Eu-copolymers. A study of the depende nce of emission intensities of the Eu-copolymers on the Eu content showed t hat the emission intensities increased nearly linearly with increasing Eu c ontent, and no significant emission concentration quenching phenomenon was observed at the Eu content of 0-6.38 mol %. This indicates that the Eu-comp lex units in the Eu-copolymers are very uniformly bonded to the polymer cha in, which is in good agreement with the result of polymer structure analysi s.