A Laboratory for Gaseous Diffusion Through Permeable Solids: The Time Lag
A simple laboratory setup dedicated to the study of transitory gas transfer through permeable solids in a flat design (polymer films, metal or ceramic porous supports, catalysts, adsorbents) is described. An illustrative application for oxygen and nitrogen transport through an elastomer matrix (Silastic) is presented. Data treatment, performed according to the time-lag technique, leads to the sorption and diffusion coefficients of the gas through the solid, as well as to the overall permeability. Based on these aspects, a didactic tutorial for an undergraduate laboratory is proposed.