Nonequilibrium thermodynamics and boundary conditions for reaction and transport in heterogeneous media

TL;DR

This paper develops a thermodynamic framework for understanding how surface reactions influence diffusiophoresis and reciprocal effects at fluid-solid interfaces, with analytical and numerical validation.

Contribution

It introduces a formulation of nonequilibrium interfacial thermodynamics incorporating surface reactions, extending the understanding of diffusiophoresis and reciprocal effects.

Findings

Surface reactions modify diffusiophoretic effects.

Analytic formulas for interfacial phenomena are derived.

Numerical tests confirm theoretical predictions.

Abstract

Nonequilibrium interfacial thermodynamics is formulated in the presence of surface reactions for the study of diffusiophoresis in isothermal systems. As a consequence of microreversibility and Onsager-Casimir reciprocal relations, diffusiophoresis, i.e., the coupling of the tangential components of the pressure tensor to the concentration gradients of solute species, has a reciprocal effect where the interfacial currents of solutes is coupled to the slip velocity. The presence of surface reactions is shown to modify the diffusiophoretic and reciprocal effects at the fluid-solid interface. The thin-layer approximation is used to describe the solution flowing near a reactive solid interface. Analytic formulas describing the diffusiophoretic and reciprocal effects are deduced in the thin-layer approximation and tested numerically for the Poiseuille flow of a solution between catalytic planar surfaces.