Substructure shock-friction theory for molecular transport in liquids

摘要

Transport properties, such as viscosity and diffusion coefficient, are of fundamental importance in chemical processes and in formulation science. In this paper, a mathematically simple theory, based on frictions between "substructures", which are effective units of motion, and contact probabilities, is proposed for transport properties. Its predictive power is demonstrated on viscosity. Fitted on a set of 82 pure liquids containing molecules of various sizes, rigidities, and functionalities, with many of them multifunctional and/or hydrogen-bonded, the method is then tested on 882 binary mixtures (represented by 13,687 compositions and containing 234 different compounds), yielding a standard error of 0.30 log units. This corresponds to an accuracy of a factor of two, in line with other free energy-based predictions methods like COSMO-RS, supporting a pseudo-thermodynamic representation of transport properties. (C) 2021 Elsevier B.V. All rights reserved.