Free radical motion in super critical fluids probed by EPR spectroscopy
Article Abstract:
Electron paramagnetic resonance spectroscopic studies were performed to describe free radical reactions in the 2,2,6,6-tetramethyl-1-piperidinyloxy radical in super critical fluids (SCF). In addition, liquid ethanol, n-hexane and other nitroxide samples were also examined. The spin rotation and Heisenberg spin-exchanges of the free radical samples were measured. The findings revealed that solvent density regulates the spin rotation and spin exchange rates among nitroxides in SCFs. Moreover, free radical motion may be determined if the SCF density is lower than the critical density.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
Spin exchange of cation radicals in solid polymeric matrixes
Article Abstract:
Research was conducted to examine the spin exchange of cation radicals in solid polymeric matrixes. Electron paramagnetic resonance spectroscopy was used to determine the rate of spin exchange between cation radicals held in rigid polymeric matrixes. Various diamagnetic compounds were added to the samples to investigate the idea of "superexchange" which was proposed in earlier work. Results indicate that the mechanism is incorrect and that the measurement of exchange energies can be employed to find relative separations of radicals held in the polymeric matrixes.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
High dielectric hyperbalanced polyaniline materials
Article Abstract:
The effect of the microcrystalline size dependence of different polyaniline polymeric systems on the dielectric constant is examined. The mechanism of the increased dielectric response at higher frequencies is investigated by EPR spectroscopy and the results have shown that delocalized polarons might provide a way to boost the dielectric response at high frequency.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2006
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Excited-state localization in a 3-fold-symmetric molecule as probed by electroabsorption spectroscopy. Effects of disorder-induced symmetry breaking on the electroabsorption properties of a model dendrimer
- Abstracts: Interactions in noncovalent PAMAM/TMPyP systems studied by fluorescence spectroscopy. Early aggregation in prion peptide nanostructures investigated by nonlinear and ultrafast time-resolved fluorescence spectroscopy
- Abstracts: Distribution of cations and vacancies in TaFe1.25Te3 studied by Mossbauer spectroscopy. Interpreting the oxidative catalytic activity in iron-substituted ferrierites using in situ Mossbauer spectroscopy
- Abstracts: Formation of ultrasharp vertically aligned Cu-Si nanocones by a DC plasma process. Comment on "acidity of a Cu-bound histidine in the binuclear center of cytochrome c oxidase"
- Abstracts: Mobility of the acidic protons in H-ZSM-5 as studied by variable temperature H MAS NMR. Solvation structure and transport of acidic protons in ionic liquids: A first-principles simulation study