Permeability of PTFE studied with a potentiometric SO2-sensitive sensor

Permeability of PTFE to SO2 is studied by the least-squares fitting of the dynamic response of a potentiometric sensor with PTFE as gas-permeable membrane. oposed method establishes D×k product values for the diffusion of SO2 through PTFE that may be compared with the reported D×k product value at the diffusion through dimethylsilocone rubber. It also evidences morphology differences between the considered PTFE samples, especially in the low concentration range that yield to the very long recovery time of the sensor, i.e. the variation of the superficial tension in the triphasic SO2/PTFE/internal electrolyte system. thod is accessible and may be used for the study of the permeability of other polymeric membranes or triphasic systems.