Correlation of the scaling exponent of the diffusivity-density function in viscous liquids with their elastic properties

TL;DR

This paper establishes a theoretical link between the density scaling exponent of diffusivity in viscous liquids and their elastic properties, specifically relating it to the pressure derivative of the bulk modulus, using thermodynamics and defect models.

Contribution

It introduces a new theoretical formulation connecting diffusivity scaling to elastic properties in viscous liquids, grounded in thermodynamics and defect elastic models.

Findings

The scaling exponent is related to the pressure derivative of the bulk modulus.

A straightforward proof links diffusivity scaling to elastic properties.

The model provides a fundamental understanding of diffusivity behavior in viscous liquids.

Abstract

Fundamental thermodynamical concepts and a solid-state point defect elastic model are used to formulate a diffusivity-density scaling function for viscous liquids. It is proved in a straightforward manner that the scaling exponent describing the density scaling of the diffusivity, is related with the pressure derivative of the isothermal bulk modulus.