Identifying the structural relaxation dynamics in a strongly asymmetric binary glass former

Autor: Zijing Li, Li-Min Wang, Yingdan Liu, Xiao Jin, Shidong Feng
Rok vydání: 2021
Předmět:
Zdroj: The Journal of Chemical Physics. 154:144504
ISSN: 1089-7690
0021-9606
DOI: 10.1063/5.0046361
Popis: Here, we provide calorimetric and dielectric studies in asymmetric binary mixtures constituted by 2-picoline and triphenylethylene. Extreme broadening of the calorimetric glass transition is observed in the mixtures, which is accompanied by a large mismatch of the glass transition temperatures defined by the two techniques. As large broadening in the relaxation dispersion is identified in the mixtures of intermediate concentrations, strong temperature dependence of the relaxation dispersion is detected. The relation between the stretching exponent and non-linear factor derived from the Tool-Narayanaswamy-Moynihan-Hodge model shows a remarkable shift from the one established by pure molecular glass formers and symmetric mixtures. The unusual behaviors suggest an extreme dynamical decoupling mode imposed by the occurrence of strong concentration fluctuation.
Databáze: OpenAIRE