Experimental Studies On The Fluorescent Property Of Optical Resin Containing Lanthanide (Europium Ⅲ) Organic Complex

Compounds containing rare earth ions have long been used asfluorescent and laser materials due to their sharp intensely luminescent f-felectronic transitions. Unfortunately, since the f-f transitions of rare earthions are forbidden by the selection rule, they absorb very little excitationenergy. Photoactive rare earth organic complex exhibits intense narrowemission band via an effective intramolecular energy transfer from theligands to the metal ions under excitation by near ultraviolet light, which iscalled the antenna effect.Therefore, they are expected to be promising luminescent dopants forthe preparation of hybrid fluorescent and other optical sources.However, most of the researches concerning lanthanide b-diketonatechelates have been mainly focused on the solid complexes themselves andthe practical applications of organic rare earth complexes are hindered bytheir weaknesses such as thermal and luminescence stability et al. A varietyof approaches have been developed to overcome the above-mentionedweaknesses and to enlarge their application range.The synthesis of polymer composite materials containing lanthanideorganic complexes is an important approach to the preparation ofphotoelectric functional materials. In the synthetic process, the partial polargroup in polymer chains is able to replace some micro-molecule ligand(such as water) in lanthanide complex occurring interaction with lanthanideion, leading to the profound effect of the structure and performance oflanthanide polymer composite materials.In this paper, the copolymer system of styrene/α-methyl acrylic acidwhich can coordinate with lanthanide and possess polymeric activity wasselected. Novel composite resins possessing good luminescent propertieshave been synthesized through a free radical copolymerization of styrene,α-methyl acrylic acid and the binary or ternary complexes of lanthanideions (Eu3+). We characterized the molecular structure, physical andmechanical performance, and the luminescent properties of the compositeresins. Spectra investigation indicated that α-methyl-acrylic acid act asboth solubilizer and coligand. Photoluminescence measurement indicatedthat the lanthanide complexes show superior emission lines and higherintensities in the resin matrix than in the corresponding pure complexpowders (although the complex content in copolymer system is only 0.31wt%). The phenomenon can be attributed to the restriction of molecularmotion of complexes by the polymer chain networks and the exclusion ofwater molecules from the complex. These results indicated that thesecomposite resins possessed better transparency (80～89%) and mechanicalperformance. The lifetime of the lanthanide complexes is lengthened whenthey were incorporated in the polymer matrix(except Eu(DBM)3CPC).