Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Assunto da revista
País de afiliação
Intervalo de ano de publicação
1.
J Fluoresc ; 32(4): 1509-1516, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35522344

RESUMO

Optical and photophysical properties of 6-substituted-1,2,4-Triazine fluorescent derivative dye doped in silicate based sol-gel, homopolymer of methyl methacrylate (PMMA), and copolymer (MMA/diethylene glycol dimethacrylate) (DEGDMA) were investigated. The pores of different hosts and caging of the dye were found to effect on the parameters such as molar absorptivity, cross sections of singlet-singlet electronic absorption and emission spectra, excited state lifetime, quantum yield of fluorescence. The dipole moment of electronic transition, the length of attenuation and oscillator strength of electronic transition from So → S1 have been calculated. The dye was pumped with different powers using 3rd harmonic Nd: YAG laser of 355 nm and pulse duration 8 ns, with repetition rate 10 Hz. Good photo stability for dye was attained. After 55,000 pumping pulses of (10 mJ/pulse), the photo-stabilities were decreased to 53%, 48%, and 45% of the initial ASE of dye in sol gel, PMMA, and Co-polymer respectively. The dye in sol-gel matrix showed improvement of photo stability compared with those in organic polymeric matrices.

2.
J Fluoresc ; 31(5): 1547-1554, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34331183

RESUMO

This paper deals with the optical and photophysical properties of dihydrophenanthro[9,10-e][1,2,4]triazine fluorescent dyes doped in Silicate based sol-gel and homo-poly methyl methacrylate (PMMA). Solid hosts were found to effect on the optical and photophysical parameters such as molar absorptivity, cross sections of singlet-singlet electronic absorption and emission spectra, excited state lifetime, quantum yield of fluorescence. The dipole moment of electronic transition, the length of attenuation and oscillator strength of electronic transition from So → S1 have been calculated. The dyes were pumped with different powers using 3rd harmonic Nd:YAG laser of 355 nm and pulse duration 8 ns, with a repetition rate at (10 Hz). Good photostability for compounds 1 and 2 were attained. It was decreased to 49% & 54% and 46% & 40% of the initial ASE of dyes in sol gel and PMMA, respectively, after 55,000 pumping pulses at (10 mJ/pulse). The dyes in sol-gel showed improved photostability compared with those in organic polymeric matrices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA