Journal of Polymer Science Part B: Polymer Physics, Vol.39, No.13, 1496-1504, 2001
Onsager consistency checks for multicomponent diffusion models
The Onsager reciprocity relations are applied to several recently proposed multicomponent diffusion models in an attempt to gauge their validity and ascertain their applicability. Each of these friction-based diffusion models stems from the more general Bearman formalism through various assumptions regarding the individual friction coeffcients, By assessing the compliance of the Bearman model with respect to the Onsager relations, we ascertain the validity of the simplifications introduced to each diffusion model and suggest which postulates lead to results consistent with the Onsager relations. Although some models are not consistent with the Onsager relations, each model predicts the multicomponent drying of polymer films reasonably well. The necessity for consistency with the Onsager development is, therefore, revisited.
Keywords:self-diffusion;mutual diffusion;multicomponent diffusion;cross coefficients;friction coefficients;transport;Onsager;drying