Comments on Thermodiffusion: The physico-chemical mechanics view. J. Chem. Phys. 154, 024112 (2021)

TL;DR

This paper critically examines the framework for chemical transport and thermodiffusion proposed by Kocherginsky and Gruebele, highlighting their contributions and clarifying some confusions in the theoretical derivation of Soret coefficients.

Contribution

It provides a detailed critique and clarification of the physico-chemical mechanics view on thermodiffusion, emphasizing the macroscopic derivation of Onsager relations without microscopic assumptions.

Findings

Clarification of the systematic framework for thermodiffusion

Discussion of the macroscopic derivation of Onsager relations

Identification of confusions in previous theoretical approaches

Abstract

In a series of publications, Kocherginsky and Gruebele presented a systematic framework for chemical transport and thermodiffusion to predict the Soret coefficients from thermodynamics. A macroscopic derivation of the Onsager reciprocal relations without recourse to microscopic fluctuations or equations of motion was also discussed. Their important contributions and some confusions are discussed.