Physics of Polymers at the Italian High-Field EPR Facility: Heterogeneities and Fast Dynamics |
| |
| Authors: | V. Bercu M. Martinelli C. A. Massa L. A. Pardi D. Leporini |
| |
| Affiliation: | (1) Istituto per i Processi Chimico Fisici, Consiglio Nazionale delle Ricerche, Pisa, Italy;(2) Dipartimento di Fisica "Enrico Fermi", Università di Pisa, Pisa, Italy;(3) Research Center Soft, Istituto Nazionale per la Fisica della Materia, Consiglio Nazionale delle Ricerche, Pisa, Italy |
| |
| Abstract: | The reorientation of the paramagnetic molecule 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) dissolved in glassy polystyrene (PS) is studied by electron paramagnetic resonance (EPR) spectroscopy in a wide range of Larmor frequencies (9–285 GHz). High-field EPR reveals that TEMPO rotates by small angular steps with a distribution of correlation times and is able to detect the onset of fast motion of PS. Differently, X-band EPR shows that TEMPO undergoes a large-angle reorientation with virtually no distribution of correlation times and largely misses the fast dynamics of PS. A unified view is proposed. Authors' address: Dino Leporini, Dipartimento di Fisica "Enrico Fermi", Università di Pisa, Largo Pontecorvo 3, Pisa 56127, Italy |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
