Experimental determination of self-diffusivities through a polymer network for single components in a mixture

► Tracer diffusion coefficients in a multicomponent solvent-solvent-polymer system were successfully estimated by PFG-NMR measurements on a free-standing crosslinked PDMS. ► Experimental diffusivities were correlated with available diffusion models (i.e., Vrentas & Duda diffusion theory and Wesselingh & Bollen multicomponent diffusion model). Therefore, a method was developed to calculate free volume parameters of the compounds/system. ► A discussion about advantages, disadvantages, theoretical limitations, necessary assumptions, as well as a way to proceed in modeling of nanofiltration has been done.