کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1686082 | 1518757 | 2008 | 7 صفحه PDF | دانلود رایگان |
Electron spin resonance spectroscopy investigations on γ irradiated 3-methyl nylon 3 (poly-3-methyl β-alanine) are reported. The resonance spectra (recorded after the irradiation in nitrogen atmosphere has been stopped) have been attributed to the parallel and perpendicular components of a triplet line assigned to the delocalization of the uncoupled electron over an effective nuclear spin 1. It was suggested that this effective spin arises from the fast tunneling/rotation of a proton between two positions. The resonance spectra have been simulated with accuracy by using a simplified spin Hamiltonian and assuming Lorentzian-like resonance line shapes and axial asymmetry of the resonance line due to the trapping of free radicals in randomly oriented crystallites. The time evolution of free radicals in nitrogen atmosphere at room temperature has been analyzed. The decay kinetics of stable free radicals in 3-methyl nylon 3 (under inert atmosphere) has been investigated. It was shown that the radiation-induced radicals in inert atmosphere decay through a unimolecular reaction.
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 266, Issues 12–13, June 2008, Pages 3100–3106