NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

An Entropy Scaling Demarcation of Gas- and Liquid-like Fluid Behaviors

Published

Author(s)

Ian H. Bell, Guillaume Galliero, Stephanie Delage-Santacreu, Lorenzo Costigliola

Abstract

In this work we propose a generic and simple definition of a line separating gas-like and liquid-like fluid behaviors in the supercritical region. We argue that this line is defined by the location of the minimum of the macroscopically scaled viscosity when plotted as a function of the excess entropy, which differs from the popular Widom and Frenkel lines. For hard sphere, Lennard-Jones, and inverse-power-law fluids, such a line is located at a excess entropy approximately equal to -2/3 times Boltzmann's constant and corresponds to points in the thermodynamic space for which the kinetic contribution to viscosity is approximately half of the total viscosity. For flexible Lennard-Jones chains, the transitional excess entropy is a linear function of the chain length. This definition opens a straightforward route to classify the dynamic behavior of supercritical fluids from a single thermodynamic quantity obtainable from high-accuracy thermodynamic models. This methodology also applies to fluids without attraction, unlike the Widom lines.
Citation
The Journal of Chemical Physics
Volume
152
Pub Type
Journals

Download Paper

https://doi.org/10.1063/1.5143854
Local Download
Thermodynamics

Citation

Bell, I. , Galliero, G. , Delage-Santacreu, S. and Costigliola, L. (2020), An Entropy Scaling Demarcation of Gas- and Liquid-like Fluid Behaviors, The Journal of Chemical Physics, [online], https://doi.org/10.1063/1.5143854 (Accessed October 14, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created March 31, 2020, Updated July 8, 2020
Was this page helpful?