Solid-state nuclear magnetic resonance study of relaxation processes in MEH-PPV

Autor:	Rodrigo Fernando Bianchi, Tito José Bonagamba, Débora Terezia Balogh, Roberto Mendonça Faria, Teresa D. Z. Atvars, Eduardo R. deAzevedo, A. C. Bloise, R. F. Cossiello
Rok vydání:	2005
Předmět:	Molecular dynamics Photoluminescence Materials science Solid-state nuclear magnetic resonance Relaxation (NMR) Libration Side chain Physical chemistry Atomic physics Atmospheric temperature range Condensed Matter Physics Rotation Electronic Optical and Magnetic Materials
Zdroj:	Physical Review B. 71
ISSN:	1550-235X 1098-0121
DOI:	10.1103/physrevb.71.174202
Popis:	Solid-state nuclear magnetic resonance methods were used to study molecular dynamics of MEH-PPV at different frequency ranges varying from 1 Hz to 100 MHz. The results showed that in the 213 to 323 K temperature range, the motion in the polymer backbone is predominantly slow (Hz--kHz) involving small angle librations, which occurs with a distribution of correlation times. In the side chain, two motional regimes were identified: Intermediate regime motion (1--50 kHz) for all chemical groups and, additionally, fast rotation $(\ensuremath{\sim}100\phantom{\rule{0.3em}{0ex}}\mathrm{MHz})$ for the terminal $\mathrm{C}{\mathrm{H}}_{3}$ group. A correlation between the motional parameters and the photoluminescent behaviors as a function of temperature was observed and is discussed.
Databáze:	OpenAIRE
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