How Free Volume Does Influence the Dynamics of Glass Forming Liquids
| Autor: | Jane E. G. Lipson, Ronald P. White |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Physics
Mathematical optimization Polymers and Plastics Organic Chemistry Thermodynamics Inverse 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Glass forming 0104 chemical sciences Inorganic Chemistry Lattice (order) Materials Chemistry 0210 nano-technology |
| Zdroj: | ACS macro letters. 6(5) |
| ISSN: | 2161-1653 |
| Popis: | In this article we show that inverse free volume is a natural variable for analyzing relaxation data on glass-forming liquids, and that systems obey the general form, log(τ/τref) = (1/Vfree) × f(T), where f(T) is a function of temperature. We demonstrate for eight glass-forming liquids that when experimental relaxation times (log τ), captured over a broad pressure–volume–temperature (PVT) space, are plotted as a function of inverse free volume (1/Vfree), a fan-like set of straight line isotherms with T-dependent slopes ensues. The free volume is predicted independently of the dynamic results for each state point using PVT data and the Locally Correlated Lattice (LCL) equation of state. Taking f(T) ∝ 1/Tb, we show that, for each of the systems studied, only the single, system-dependent parameter, b, is required to collapse the fan of linear isotherms into a straight line. We conclude that log τ is a function of the combined variable, 1/(VfreeTb), and because it is linear, it allows us to write an explicit ... |
| Databáze: | OpenAIRE |
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