Probing the link between residual entropy and viscosity of molecular fluids and model potentials

Published

December 24, 2018

Author(s)

Ian H. Bell

Abstract

This work investigates the link between residual entropy and viscosity based on wide-ranging, highly accurate experimental ans simulation data. This link was originally postulated by Rosenfeld in 1977, and it is shown that this scaling results in an approximately monovariate relationship between residual entropy and reduced viscosity for a wide range of molecular fluids (argon, methane, CO2, Sf6, refrigerant R-134a (1,1,1,2-tetrafluoroethane), refrigerant R-125 (pentafluoroethane), methanol, and water), and a wide range of model potentials (hard sphere, inverse power, Lennard-Jones, and Weeks-Chandler-Andersen). While the propsed "universal" correlation of Rosenfeld is shown to be far from universal, when used with the appropriate density scaling for molecular fluids, the viscosity of non-associating molecular fluids can be mapped onto the model potentials. This mapping results in a length scale that is proportional to that obtained from experimentally measureable liquid density values.

Citation

Proceedings of the National Academy of Sciences of the United States of America

Pub Type

Journals

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Keywords

viscosity, entropy, transport

Citation

Bell, I. (2018), Probing the link between residual entropy and viscosity of molecular fluids and model potentials, Proceedings of the National Academy of Sciences of the United States of America, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926626 (Accessed December 26, 2024)