On the mutual relationships between spin probe mobility, free volume and relaxation dynamics in organic glass-formers: Glycerol

• Published in: Chemical physics letters Vol. 670; pp. 58 - 63
• Main Authors: Bartoš, J., Švajdlenková, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.02.2017
• Subjects: BDS; ESR; Free volume; Molecular mobility; PALS; Relaxation dynamics; BDS; Free volume; Relaxation dynamics; Molecular mobility; ESR; PALS
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2016.12.064

[Display omitted] •Spin probe TEMPO dynamics in glycerol (GL) measured by ESR.•Ortho-positronium (o-Ps) annihilation study in GL performed by PALS.•The mutual relationships between the characteristic ESR and PALS temperatures Tx1slow,τ≡Tb1L and Tcτ≡Tb2L.•The secondary β- and the primary α relaxation from BDS as underlying physical processes influencing or controlling the rotation dynamics of TEMPO and o-Ps annihilation, respectively. β and α relaxation from BDS control rotation dynamics of TEMPO and o-Ps annihilation. The rotation dynamics of the spin probe TEMPO in glycerol from ESR is compared with the ortho-positronium (o-Ps) annihilation from PALS and interpreted using the relaxation dynamics from BDS. Rotation time scale within the slow motion regime exhibits two Arrhenius regions with the characteristic ESR temperature, TX1τ, close to the characteristic PALS temperature, Tb1L, which is related to the secondary β process above Tg. Next, a slow to fast motion regime transition at the characteristic ESR temperature, Tcτ, close to the characteristic PALS temperature, Tb2L, followed by non-Arrhenius fast motion regime region is fully coupled with the primary α process.