On the Proper Use of Concentration Profiles for Determining Polymer Diffusion Coefficients via Fluorescence Nonradiative Energy Transfer

1997 ◽  
Vol 30 (18) ◽  
pp. 5560-5562 ◽  
Author(s):  
Gregory A. O'Neil ◽  
John M. Torkelson
Keyword(s):  
Energy Transfer ◽  
Diffusion Coefficients ◽  
Nonradiative Energy Transfer ◽  
Concentration Profiles ◽  
Polymer Diffusion

Recent Applications of Nonradiative Energy Transfer to Polymer Studies

1993 ◽  
Vol 58 (10) ◽  
pp. 2266-2271 ◽  
Author(s):  
Herbert Morawetz
Keyword(s):  
Energy Transfer ◽  
Polymer Chain ◽  
Cluster Formation ◽  
Nonradiative Energy Transfer ◽  
Molecular Cluster ◽  
Fluorescent Labels ◽  
Latex Particles ◽  
Polymer Latex

Recent studies of polymers in solution and in bulk by energy transfer between two fluorescent labels are reviewed. Such studies are concerned with the equilibrium and dynamics of polymer chain expansion, molecular cluster formation in solution, the miscibility of polymers in bulk, and the interdiffusion of polymer latex particles.

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

Luminescence Linewidth Broadening and Nonradiative Energy Transfer Studies of Solid UO2+2-Datura

1992 ◽  
Vol 46 (9) ◽  
pp. 1376-1381 ◽  
Author(s):  
Huei-Yang D. Ke ◽  
Gary D. Rayson
Keyword(s):  
Energy Transfer ◽  
Emission Spectra ◽  
Blue Shift ◽  
Liquid Nitrogen Temperature ◽  
Peak Position ◽  
Nonradiative Energy Transfer ◽  
Wall Material ◽  
Transfer Model ◽  
Solution Ph ◽  
Linewidth Broadening

The emission spectra and fluorescence decay curves of solid UO2+2- Datura at liquid nitrogen temperature have been measured. The linewidth of the emission peaks of UO2+2 ions in UO2+2- Datura decreases with the UO2+2 concentration. This linewidth broadening phenomenon can be explained by the existence of resonance interactions between adjacent UO2+2- Datura species. The analysis of the emission peak position of the bound ions has been used to provide a measure of the electronic factors contributing to the interaction between the uranyl ion and phosphoryl and dicarboxyl moieties on the cell wall material. An observed blue shift of the uranyl fluorescence spectrum as a function of solution pH has been ascribed to a distortion of the normally linear O-U-O bond. An inter- and intra-molecular nonradiative energy transfer model has been successfully used to interpret the measured lifetime data of UO2+2- Datura.

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