Determination of the Thermodynamic Scaling Exponent from Static, Ambient-Pressure Quantities

Abstract

An equation is derived that expresses the thermodynamic scaling exponent, g, which superposes relaxation times and other measures of molecular mobility determined over a range of temperatures and densities, in terms of static, physical quantities. The latter are available in the literature or can be measured at ambient pressure. We show for 13 materials, both molecular liquids and polymers, that the calculated g are equivalent to the scaling exponents obtained directly by superpositioning. The assumptions of the analysis are that the glass transition is isochronal and that the first Ehrenfest relation is valid; the first assumption is true by definition, while the second has been corroborated for many glass-forming materials at ambient pressure. However, we find that the Ehrenfest relation breaks down at elevated pressure, although this limitation is of no consequence herein, since the appeal of the new equation is its applicability to ambient pressure data.

arXiv comment9 pages, 3 figures, 1 table

References in corpus (20)

• Thermodynamical Scaling of the Glass Transition Dynamics
• Thermodynamic Scaling of the Viscosity of Van Der Waals, H-Bonded, and Ionic Liquids
• Pressure-energy correlations in liquids. I. Results from computer simulations
• Scaling out the density dependence of the $\alpha$ relaxation in glassforming polymers
• Thermodynamic interpretation of the scaling of the dynamics of supercooled liquids
• Pressure-energy correlations in liquids. II. Analysis and consequences
• Strong pressure-energy correlations in van der Waals liquids
• Scaling the alpha-relaxation time of supercooled fragile organic liquids
• Scaling of the supercooled dynamics and its relation to the pressure dependences of the dynamic crossover and the fragility of glass-formers
• Thermodynamic scaling of diffusion in supercooled Lennard-Jones liquids
• Beyond power-law density scaling: Theory, Simulation, and Experiment
• A repulsive reference potential reproducing the dynamics of a liquid with attractions
• Ehrenfest relations at the glass transition: solution to an old paradox
• Pressure-energy correlations and thermodynamic scaling in viscous Lennard-Jones liquids
• Statistical mechanics of Roskilde liquids: Configurational adiabats, specific heat contours and density dependence of the scaling exponent
• Glass-forming liquids: One or more "order" parameters?
• Effect of Chemical Structure on the Isobaric and Isochoric Fragility in Polychlorinated Biphenyls
• Scaling of Volumetric Data in Model Systems Based on the Lennard-Jones Potential
• Entropy Basis for the Thermodynamic Scaling of the Dynamics of OTP
• Effect of entropy on the dynamics of supercooled liquids: New results from high pressure data

Cited by in corpus (11)

• Dynamic Correlation Length Scales under Isochronal Conditions
• Equation of State and Entropy Theory Approach to Thermodynamic Scaling in Polymeric Glass-Forming Liquids
• Thermodynamic scaling of vibrational dynamics and relaxation
• Corroborative evidences of TVgamma-scaling of the alpha-relaxation originating from the primitive relaxation/JG beta relaxation
• Experimental evidence of a state-point dependent scaling exponent of liquid dynamics
• Qualitative change in structural dynamics of some glass-forming systems
• Scaling of the dynamics of flexible Lennard-Jones chains. II. Effects of harmonic bonds
• A pathway towards proper modeling of physical properties
• Combined Description of Pressure-Volume-Temperature and Dielectric Relaxation of Several Polymeric and Low-Molecular-Weight Organic Glass-Formers using 'SL-TS2' Mean-Field Approach
• Thermodynamics and dynamics of the inherent states at the glass transition
• The origin of the density scaling exponent for polyatomic molecules and the estimation of its value from the liquid structure