Dye Mixtures for Ultrafast Wavelength Shifters

1994 ◽  
Vol 348 ◽  
Author(s):  
S. Cangopadhyay ◽  
N. Barashkov ◽  
L. Liu ◽  
C. Palsule ◽  
W. Borst ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Fluorescence Spectra ◽  
Continuous Wave ◽  
Quantum Yields ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Epoxy Polymers ◽  
Decay Times ◽  
The Mean ◽  
Coumarin Dyes

ABSTRACTWe have produced fast wavelength shifters using mixtures of various Coumarin dyes with DCM in epoxy-polymers (DGEBA+HHPA) and measured the properties of these wavelength shifters. The particular mixtures were chosen because there is a substantial overlap between the emission spectrum of Coumarin and the absorption spectrum of DCM. The continuous wave and time-resolved fluorescence spectra have been studied as a function of component concentration to optimize the decay times, emission peaks and quantum yields. The mean decay times of these mixtures are in the range of 2.5-4.5 ns. The mean decay time increases with an increase in Coumarin concentration at a fixed DCM concentration or with a decrease in DCM concentration at a fixed Coumarin concentration. This indicates that the energy transfer is radiative at lower relative DCM concentrations and becomes non-radiative at higher DCM concentrations.

Fluorescence dynamics of poly (N-vinylcarbazole) in fluid solution. Multivariate analysis of time-resolved fluorescence spectra

1993 ◽  
Vol 208 (3-4) ◽  
pp. 283-289 ◽  
Author(s):  
Hisashi Sakai ◽  
Akira Itaya ◽  
Hiroshi Masuhara ◽  
Keiji Sasaki ◽  
Satoshi Kawata
Keyword(s):  
Multivariate Analysis ◽  
Fluorescence Spectra ◽  
Fluid Solution ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Lifetimes of normal and tumorous human lung tissues by time-resolved fluorescence spectra

1996 ◽  
Author(s):  
Wei Zheng ◽  
Zhiwei Huang ◽  
Shusen Xie ◽  
Teck-Chee Chia ◽  
Zukang Lu ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Human Lung ◽  
Time Resolved Fluorescence ◽  
Time Resolved

scholarly journals Effect of the Substitution Position on the Electronic and Solvatochromic Properties of Isocyanoaminonaphthalene (ICAN) Fluorophores

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2434 ◽  
Author(s):  
Sándor Lajos Kovács ◽  
Miklós Nagy ◽  
Péter Pál Fehér ◽  
Miklós Zsuga ◽  
Sándor Kéki
Keyword(s):  
Radiative Decay ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Decay Rates ◽  
Quantum Yields ◽  
Time Resolved Fluorescence ◽  
Solvatochromic Shift ◽  
Fluorescence Emission Spectra ◽  
Time Resolved ◽  
Donor And Acceptor

The properties of 1,4-isocyanoaminonaphthalene (1,4-ICAN) and 2,6-isocyanoaminonaphthalene (2,6-ICAN) isomers are discussed in comparison with those of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which exhibits a large positive solvatochromic shift similar to that of Prodan. In these isocyanoaminonaphthalene derivatives, the isocyano and the amine group serve as the donor and acceptor moieties, respectively. It was found that the positions of the donor and the acceptor groups in these naphthalene derivatives greatly influence the Stokes and solvatochromic shifts, which decrease in the following order: 1,5-ICAN > 2,6-ICAN > 1,4-ICAN. According to high-level quantum chemical calculations, this order is well correlated with the charge transfer character of these compounds upon excitation. Furthermore, unlike 1,5-ICAN, the 1,4-ICAN and 2,6-ICAN isomers showed relatively high quantum yields in water, that were determined to be 0.62 and 0.21, respectively. In addition, time-resolved fluorescence experiments revealed that both the radiative and non-radiative decay rates for these three ICAN isomers varied unusually with the solvent polarity parameter ET(30). The explanations of the influence of the solvent polarity on the resulting steady-state and time-resolved fluorescence emission spectra are also discussed.

Lumineszenzuntersuchungen zum Problem der Energieübertragung in organischen Molekülkristallen

1970 ◽  
Vol 25 (6) ◽  
pp. 955-966 ◽  
Author(s):  
F. Belitz
Keyword(s):  
Energy Transfer ◽  
Single Crystals ◽  
Fluorescence Spectra ◽  
Dipole Interaction ◽  
Main Process ◽  
Transfer Processes ◽  
Decay Times ◽  
Different Types ◽  
The Mean ◽  
Host Lattices

Abstract From fluorescence spectra and decay times of single crystals of 2.3-dimethylnaphthalene, phenanthrene and p-terphenyl doped with one or two different types of fluorescence molecules (anthracene and, or tetracene) informations about the energy transfer processes are obtained. For doping concentrations smaller than 4·10-4 Mol/Mol the transfer by excitons is the main process. The dipole-dipole interaction over distances more than 80 Å (14 mean molecular distances) can be excluded. The mean travelling distance of the excitons in the three host lattices was found to be 250 - 300 mean molecular distances.

scholarly journals Photophysics on Solid Surfaces. Time-Resolved Fluorescence Spectra of Pyrene Adsorbed on Calcinated Vycor Glass

1990 ◽  
Vol 63 (9) ◽  
pp. 2475-2480 ◽  
Author(s):  
Tsuneo Fujii ◽  
Akira Ishii ◽  
Hiroshi Satozono ◽  
Satoshi Suzuki ◽  
Michel Che ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Solid Surfaces ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Vycor Glass
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