The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application Prediction of mutual diffusion coefficients in non-ideal binary mixtures from PFG-NMR diffusion measurements

In ideal solutions, binary, or mutual, diffusion is well described by Fick’s law, which describes the driving force for diffusion in terms of a concentration gradient. However, from a thermodynamic per-spective, the driving force is more correctly considered to be a gradient of chemical potential. The simplest analysis for a binary mixture suggests that the molar flux can be written as [1]: j1 =−D12cdx1dz =−