Advanced methods for analysis of mixed gas diffusion in polymeric membranes

The rapid advancement of membrane gas separation processes has spurred the development new and more efficient materials, including polymers intrinsic microporosity. full exploitation such materials requires thorough understanding their transport properties, which in turn necessitates use powerful reliable characterization methods. Most methods focus on permeability, diffusivity solubility single gases or only permeability mixed gases, while studies reporting diffusion mixtures are extremely rare. In this paper we report a mass-spectrometric residual analyser to follow transient phase through benzotriptycene-based ultrapermeable polymer microporosity (PIM-DTFM-BTrip) polydimethylsiloxane (PDMS) for comparison, via continuous online analysis permeate. Computational entire permeation curve allows calculation coefficients all individual present mixture identification non-Fickian other anomalous behaviour. parameters were analysed by three different approaches (integral, differential pulse signal), compared with results ‘classical’ time lag method gases. PDMS shows very similar cases, PIM gives depending specific instrument used. This comparative study provides deep insight into strengths limitations instruments data elaboration characterize rubbery high free volume glassy membranes fundamentally properties will be help novel materials.