Poly electron paramagnetism

Poly(acrylic acid) (PAA) with an average molecular weight of 250,000 was used to coat a dry tablet of ZnS Mn, which was obtained by compressing the powder at 173 MPa. The amount and state of doped manganous ion, Mn(II), was examined by electron paramagnetic resonance spectroscopy (EPR). EPR enables us to gather various extra information with respect to the state of Mn(II). 

Poly (methyl methacrylate) was also subjected to mechanical reaction in a vibrating mill in common solvent for several monomers (ethylene, acrylic acid and its esters, acrylonitrile and styrene) at temperatures from —196 to 20° C (22). The formation of macroradicals and their reactions were followed by EPR (electron paramagnetic resonance). The macroradicals reacted with vinyl monomers at temperatures less than —100° C, while quinones underwent reaction as low as —196° C. The same experiments were performed also with polystyrene and polybutylenedimethacrylate. The radicals from polystyrene were more reactive than those from poly(methyl methacrylate). 

Mroczka N, Bernhard WA. (1995) Electron paramagnetic resonance investigation of X-irradiated poly(U), poly(A) and poly(A) poly(U) Influence of hydration, packing and conformation on radical yield at 4 K. Radiat Res 144 251-257. 

Identification of the Source of the Electron Paramagne11sm In Poly-DCH. We have Investigated a series of possible radical site structures and models to explain the observed electron paramagnetism In poly-DCH and poly-DCHBrg. The model which holds the most promise for poly-DCH Is that proposed by Slxl and co-workers(14). 

Electron behavior, optical properties, catalytic properties, conductivity, and magnetic properties of nanocomposites were discussed in an extensive review pa-per. Complementary use of electron paramagnetic resonance and nuclear magnetic resonance helped to understand chain mobility in nanocomposites obtained from poly(ethylene oxide) encapped with triethoxy silicon. This nanocomposite is composed of PEO chains attached to silica clusters. It was found that chain fragments close to the silica clusters have hindered mobility due to the reduction of local free volume. The length of this hindered segment is estimated as three ethylene oxide units. 

Capancioni S, Schwach-Abdellaoui K, Kloeti W, et al. In vitro monitoring of poly(ortho ester) degradation by electron paramagnetic resonance imaging. Macromolecules 2003 36(16) 6135-6141. 

Chen, W.-T, G.A. Bowmaker, and R.P. Cooney. 2002. An electron paramagnetic resonance study of poly(isothianaphthene). Phys Chem Chem Phys 4 4218. 

Polypyrrole was one of the earliest conducting polymers produced. In 1968 DalT-Olio et al. [2] oxidized pyrrole in aqueous sulfuric acid to obtain a powdery precipitate on a platinum electrode. Pyrrole black, as this material became known, had a conductivity of 8 S cm". Chemical analysis determined the presence of 75% poly pyrrole and 25% sulfate anions. An intense electron paramagnetic resonance signal indicated that the polymer possessed a large number of free spins and gave a g value of 2.0026 (comparable to that of a free electron, g = 2.0023). 

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