Irreversible Thermodynamics of Vectorial Phenomena. I. The Second-Order Transport Equations of Thermal and Electrochemical Diffusion

Abstract

A phenomenological description of transport processes in concentrated multicomponent systems driven by generalized thermodynamic driving forces of vectorial character is derived by the methods of classical irreversible thermodynamics. The approach differs from that used in previous work in two major respects, first, in an emphasis in the first-order equations on the use of experimentally measurable quantities, and, second, on mathematical consistency in the derivation of the second-order equations. This second requirement is shown to lead to the introduction of a number of new transport coefficients which are analogous to the already known Thomson coefficient. A further difference lies in the fact that electroneutrality is not assumed and Poisson's equation is incorporated. A discussion of the nature and use of phenomenological transport coefficients is included, and an extension of the theory to large systems is made.