Continuous and time-resolved luminescence spectroscopy of sulfonatoporphyrin dopants in sol-gel hosts

1994 ◽  
Vol 2 (1-3) ◽  
pp. 745-749 ◽  
Author(s):  
L. M. Yates ◽  
X. -J. Wang ◽  
E. T. Knobbe
Keyword(s):  
Sol Gel ◽  
Luminescence Spectroscopy ◽  
Time Resolved

Energy Transfer And Emission Processes In Sol-Gel Materials Doped With Europium (III) Complexes

1993 ◽  
Vol 328 ◽  
Author(s):  
Xiao-Jun Wang ◽  
Lowell R. Matthews ◽  
E. T. Knobbet
Keyword(s):  
Energy Transfer ◽  
Sol Gel ◽  
Optical Emission ◽  
Luminescence Spectroscopy ◽  
Dynamic Processes ◽  
Time Resolved ◽  
Transfer Rates ◽  
Transfer Processes ◽  
Emission Behavior ◽  
Host Matrices

ABSTRACTOptical emission behavior in sol-gel-derived Materials doped with tris (4,4,4-trifluoro-l- (2′-thienyl) -l,3-butanedionato-O,O′)europium (III), Eu (ttfa)3, has been investigated by exciting the electronic levels of both europium (III) and the β-diketonate ligand (ttfa-). Energy transfer processes between the ttfa− ligands and europium (III) have been studied by time-resolved luminescence spectroscopy. The dynamic processes were compared in three sol-gel-derived host Matrices (silica, an acrylate ORMOSIL, and an epoxide ORMOSIL). Concentration dependence of the energy transfer rates was also studied.

scholarly journals Induced Crystallization In CW Laser-Irradiated Sol-Gel Deposited Titania Films

1993 ◽  
Vol 321 ◽  
Author(s):  
Gregory J. Exarhos ◽  
Nancy J. Hess
Keyword(s):  
Laser Fluence ◽  
Sol Gel ◽  
Film Stress ◽  
Amorphous Films ◽  
Time Resolved ◽  
Cw Laser ◽  
Residual Film ◽  
Titania Films ◽  
Induced Crystallization ◽  
Nanograin Size

AbstractIsothermal annealing of amorphous TiO2 films deposited from acidic sol-gel precursor solutions results in film densification and concomitant increase in refractive index. Subsequent heating above 300°C leads to irreversible transformation to an anatase crystalline phase. Similar phenomena occur when such amorphous films are subjected to focused cw laser irradiation. Controlled variations in laser fluence are used to density or crystallize selected regions of the film. Low fluence conditioning leads to the evolution of a subtle nanograin-size morphology, evident in AFM images, which appears to retard subsequent film crystallization when such regions are subjected to higher laser fluence. Time-resolved Raman spectroscopy has been used to characterize irradiated regions in order to follow the crystallization kinetics, assess phase homogeneity, and evaluate accompanying changes in residual film stress.

Time-Resolved Small Angle X-Ray Scattering and Dynamic Light Scattering Studies of Sol-Gel Transition in Gelatin

1988 ◽  
Vol 143 ◽  
Author(s):  
Dan Q. Wu ◽  
Benjamin Chu
Keyword(s):  
Light Scattering ◽  
Cross Section ◽  
Sol Gel ◽  
Slow Mode ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Intensity ◽  
Sol Gel Transition ◽  
Gel Transition

AbstractStructural and dynamical properties of an aqueous gelatin solution (5 wt%, 0.1M NaCi, pH=7) in a sol-gel transition were studied by time-resolved small angle x-ray scattering (SAXS) and dynamic light scattering (DLS) after quenching the gelatin sol at ∼45”C to 11°C. SAXS intensity measurements suggested the presence of gel fibrils which grew initially in cross-section. The average cross-section of the gel fibrils reached a constant value after an initial growth period of ∼800 sec. Further increase in SAXS intensity could be attributed to the increase in the length of the gel fibrils. Photon correlation, on the other hand, clearly showed two relaxation modes in both the sol and the gel (∼1 hr after the quenching process) states: a fast cooperative diffusion mode which remained constant from the sol to the gel state after correction for the temperature dependence of solvent viscosity; and a slow mode that could be attributed to the self-diffusion of the “free” gelatin chains and aggregates. The slow mode contribution to the time correlation function was reduced from ∼40% in sol to ∼20% in gel signaling a decrease but not the elimination of “free” particles in the gel network. The decrease in the intensity contribution by the slow mode is, however, accompanied by a large increase in the characteristic line-width distribution.

Techniques in Time-Resolved Luminescence Spectroscopy

1984 ◽  
pp. 393-407 ◽  
Author(s):  
D.L. ROSEN ◽  
A.G. DOUKAS ◽  
A. KATZ ◽  
Y. BUDANSKY ◽  
R.R. ALFANO
Keyword(s):  
Luminescence Spectroscopy ◽  
Time Resolved

scholarly journals Luminescence of uranium(VI) after liquid-liquid extraction from HCl by Aliquat® 336 in n-dodecane:1-decanol by time-resolved laser-induced luminescence spectroscopy

2020 ◽  
Vol 108 (7) ◽  
pp. 527-533 ◽  
Author(s):  
Pascal E. Reiller ◽  
Clarisse Mariet
Keyword(s):  
Organic Phase ◽  
Decay Time ◽  
Specific Interaction ◽  
Intensity Variation ◽  
Pitzer Model ◽  
Luminescence Spectroscopy ◽  
Luminescence Spectra ◽  
Time Resolved ◽  
Crystal Field Effect ◽  
Hcl Concentration

AbstractTo investigate the extraction of uranium(VI) in HCl media by Aliquat® 336 in 1:99 (v:v) 1-decanol:n-dodecane mixture, our objective is to identify the complexe(s) in the organic phase by time-resolved laser-induced luminescence spectroscopy (TRLS). The extraction mechanism is supposed to involve the formation of $[U{O_2}Cl_4^{2 - } \cdot {({R_4}{N^ + })_2}]$ in the organic phase. The occurrence of such a species leads to the presence of the ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ species in the organic solution, which luminescence shows particular features. The luminescence spectra and decay time evolutions are obtained in the organic phase as a function of HCl concentration in the aqueous phase (0.5–6 M). The extraction of ${\rm{U}}{{\rm{O}}_2}{\rm{Cl}}_4^{2 - }$ is confirmed by the particular spectrum of uranium(VI) in the organic phase, and the typical splitting of the luminescence bands, due to the crystal field effect, is clearly evidenced. The stoichiometry is verified using luminescence intensity variation as a function of the activity of Cl−, and extraction constants are calculated both using the specific interaction theory and Pitzer model. A decomposition of the spectrum of the extracted complex in the organic phase is also proposed. The decay time variation as a function of temperature allows estimating the activation energy of the luminescence process of the extracted complex.

A time-resolved luminescence spectroscopy study of non-linear optical crystals K2Al2B2O7

2012 ◽  
Vol 132 (7) ◽  
pp. 1632-1638 ◽  
Author(s):  
I.N. Ogorodnikov ◽  
V.A. Pustovarov ◽  
S.A. Yakovlev ◽  
L.I. Isaenko ◽  
S.A. Zhurkov
Keyword(s):  
Luminescence Spectroscopy ◽  
Spectroscopy Study ◽  
Time Resolved ◽  
Optical Crystals ◽  
Non Linear ◽  
Linear Optical
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