Journal ArticleDOI
Excimer formation in vinyl polymers. II. Rigid solutions of poly(2‐vinylnaphthalene) and polystyrene
Curtis W. Frank,Larry A. Harrah +1 more
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TLDR
In this article, a statistical model based on the rotational isomeric state approximation is used to formulate an expression for the fraction of excimer forming sites in the solid systems, which is consistent with an activated exciton migration to preformed excimer sites.Abstract:
Excimer formation has been examined in solid films of poly(2‐vinylnaphthalene) (P2VN) and polystyrene (PS) as a function of sample temperature from 373 to 4.2°K and film preparation temperature between 373 and 295°K. The concentration of suitable excimer forming sites in the solid state is fixed by the temperature at which the film is cast. A statistical model based on the rotational isomeric state approximation is used to formulate an expression for the fraction of excimer forming sites in the solid systems. This model makes use of the excimer site conformation energy, found to be 2500 cal for P2VN. Excimer sampling in solid solution is shown to be consistent with an activated exciton migration to preformed excimer sites. The mechanism for this process is attributed to a modulation of interchromophore separation resulting from longitudinal acoustical vibrations of the polymer chain. A semianalytical expression for the enhancement of the excitation migration is developed which has the same general form as the experimental results. The effective vibrational frequency is found to be 157 cm−1 for PS and 84 cm−1 for P2VN.read more
Citations
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Emission properties of vinylcarbazole polymers
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Luminescent solar concentrators and the reabsorption problem.
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Emission spectra of the vinyl polymers with pendant carbazolyl groups.
TL;DR: In this article, the emission properties of poly(N-vinyl carbazole) (PVCz) prepared by radical and cationic polymerization, the oligomers of poly[2-(N-carbazolyl)ethyl vinyl ether] (PCzEVE) were investigated in solutions.
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Luminescent probe studies of the microstructure and mobility of solid polymers
TL;DR: In this article, caracteristiques des sondes luminescentes et phosphorescentes, melanges de polymeres and separation de phase, coefficient de diffusion d'une molecule de polymere dans l'etat solide, les temperatures de transition Tg, Tβ et Tγ, volume libre.
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Some applications of fluorimetry to synthetic polymer studies.
TL;DR: These techniques reveal the microscopically heterogeneous distribution of species in polymer systems, which is specially pronounced in solutions of polyelectrolytes, and allow us to study conformational mobility of flexible chains, diffusion-controlled intermolecular reactions of macromolecular reagents, glass transition phenomena, and polymer compatibility.
References
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Journal ArticleDOI
Intramolecular Excimer Formation. I. Diphenyl and Triphenyl Alkanes
TL;DR: In this article, a class of compounds which are so structured that the phenyl groups along a main alkane chain are separated by exactly three carbon atoms, e.g., 1,3-diphenylpropane, 1, 3,5-triphenylpentane, has been found to possess unique fluorescence characteristics.