Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/7416
Título: | Highly photostable luminescent poly(caprolactone)siloxane biohybrids doped with europium complexes |
Autor(es): | Fernandes, M. Zea Bermudez, V. de Ferreira, R. A. Sá Carlos, Luís Charas, A. Morgado, J. Silva, Maria Manuela Smith, Michael John |
Palavras-chave: | Biohybrid Luminescent polymer Eu3+ doped network |
Data: | 2007 |
Editora: | ACS Publications |
Revista: | Chemistry of Materials |
Citação: | "Chemistry of Materials". ISSN 0897-4756. 19:16 (2007) 3892-3901. |
Resumo(s): | In this paper, we propose for the first time that the combination of a sol-gel derived diurethane cross-linked siloxane-based biohybrid host including short poly(ε-caprolactone) segments (PCL(530)) and lanthanide aquocomplexes incorporating β-diketonate ligands yields an effective protecting cage that efficiently encapsulates the emitting centers and reduces luminescence quenching. The results obtained using the Eu(tta) 3 (H 2 O) 2 (where tta - is 2-thenoyltrifluoracetonate) complex demonstrate that 1 (2) carbonyl oxygen atoms of the host matrix enter the Eu 3+ coordination shell, thus replacing the labile water molecule-(s). The significant increase in the quantum efficiency q of the doped hybrid with respect to that of Eu(tta) 3 (H 2 O) 2 (44.2 versus 29.0%, respectively) reveals that complex anchoring to the PCL(530)-based host structure contributes to enhancement of the 5 D 0 quantum efficiency. However, when a complex that contains only strong chelating ligands, such as Eu(tta) 3 phen (where phen is 1,10-phenantroline), is incorporated into the same host medium, the effect is lost and the 5 D 0 nonradiative paths in the doped hybrid are higher than those existing in the complex itself. Under UVA exposure, the emission intensity of PCL(530)/siloxane/Eu(tta) 3 (H 2 O) 2 decreased 10% in 11 h, whereas that of PCL(530)/siloxane/Eu-(tta) 3 phen decreased 25% in the same period of time. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/7416 |
DOI: | 10.1021/cm062832n |
ISSN: | 0897-4756 1520-5002 |
Versão da editora: | http://pubs.acs.org/journals/cmatex/index.html http://pubs.acs.org/cgi-bin/article.cgi/cmatex/2007/19/i16/pdf/cm062832n.pdf |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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Chem.Mater. 2007.pdf Acesso restrito! | main article with figures | 434,91 kB | Adobe PDF | Ver/Abrir |