On the multi-component diffusion in the linear region of the extended thermodynamics framework

In this work, the application of axioms such as Onsager reciprocal relations (ORR) and the quasi-equilibrium axiom for multi-component diffusion in the linear region of extended thermodynamics is investigated. It is shown that the quasi-equilibrium axiom is a direct consequence of the Galilean invariance and the ORR are compatible with this principle. This allows the formulation of diffusion models such as the Onsager–Fuoss formalism and the Maxwell–Stefan model for the multi-component diffusion in the linear region of extended thermodynamics. Moreover, criteria for the detection of extrema in the entropy production rate for multi-component diffusion are proposed. It is believed that this work could be applied in processes such as the drying of glassy coatings.