The Maxwell-Stefan theory for zeolite diffusion

Using the Maxwell-Stefan theory for microporous diffusion, the following expression can be derived for diffusion of species i in a zeolite [206,207]  

The chemical potential gradients cire related to the gradients in the component loadings by 

The more commonly used Pick diffusivity matrix is defined as 

Comparing these equations we obtain the following inter-relation between the Pick and the Maxwell-Stefan diffusivities 

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