Generalized theory of thermal transpiration and thermal diffusion based on the thermodynamics of irreversible processes

Abstract

A generalized theory of thermal transpiration and thermal diffusion based on thermodynamics of irreversible processes is developed for a mixture involving a single chemical reaction. The theory is valid even when a non-linear relation between chemical reaction rate and affinity exists but the domain of validity of the theory cannot, exceed the range of validity of the Gibbs formula for entropy production.A qualitative estimate of the difference in the values of thermal diffusion factors with and without chemical reaction for ortho and para hydrogen mixture is made. It appears that at low temperature the difference is negligible but at higher temperature it may become significant.