AI Article Synopsis
- The study focused on the stretched dynamics of molecular glass formers' structural relaxation, utilizing both dielectric and thermal relaxations.
- The researchers determined stretching exponents (β) through the Havriliak-Negami function for dielectric relaxation and the Tool-Narayanaswamy-Moynihan-Hodge formalism for enthalpic relaxation.
- They proposed a new parameter (μ*beads) to explain differences in β values for different molecules, noting that while most glass-formers show minor differences, those with high dipole moments and flexibility exhibit significant variations.
Article Abstract
We investigated the stretched dynamics of the structural relaxation in molecular glass formers by using dielectric and thermal (or enthalpic) relaxations. The dielectric stretching exponents β are determined by the Havriliak-Negami function, while the enthalpic β is quantified by using the Tool-Narayanaswamy-Moynihan-Hodge formalism. We found β is anticorrelated with the degree of freedom, a molecule addressed by the concept of beads. Referring to the reported relation of β to the dipole moment μ, we proposed a combined parameter of μ*beads, which can rationalize the difference in stretching exponents obtained by dielectric and enthalpic relaxations. For the majority of glass-forming molecules, the difference is trivial, but for those molecules with both unusually high dipole moments and flexibility, a large difference is obvious. The interplay of the degree of freedom and dielectric dipole-dipole interaction in molecular dynamics is addressed.
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| http://dx.doi.org/10.1063/5.0122186 | DOI Listing |
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Article Synopsis
- The study focused on the stretched dynamics of molecular glass formers' structural relaxation, utilizing both dielectric and thermal relaxations.
- The researchers determined stretching exponents (β) through the Havriliak-Negami function for dielectric relaxation and the Tool-Narayanaswamy-Moynihan-Hodge formalism for enthalpic relaxation.
- They proposed a new parameter (μ*beads) to explain differences in β values for different molecules, noting that while most glass-formers show minor differences, those with high dipole moments and flexibility exhibit significant variations.
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