A method whereby Onsager coefficients may be evaluated

Abstract

Much of our understanding of transport phenomena is based on linear irreversible thermodynamics formalized most notably by Onsager in 1931. As with any theory based on an a priori linear assumption, coefficients appear that may not be calculated from within the theory. In the case of transport these coefficients are usually found empirically. To correctly apply a linear theory the criteria for linearity should be evaluated. In this paper, a general theory of nonequilibrium thermodynamics, statistical rate theory, is used to outline a method whereby Onsager coefficients may be evaluated for a given circumstance. For a particular osmotic transport example, expressions for the Onsager coefficients are found which are shown to satisfy Onsager’s reciprocity hypothesis. Most importantly, criteria for linearity are explicitly formulated.