par Pourcelly, Gerald;Lindheimer, Arlette;Gavach, Claude;Hurwitz, Heinz Dieter 
Référence Journal of electroanalytical chemistry and interfacial electrochemistry, 305, 1, page (97-113)
Publication Publié, 1991-04
Référence Journal of electroanalytical chemistry and interfacial electrochemistry, 305, 1, page (97-113)
Publication Publié, 1991-04
Article révisé par les pairs
| Résumé : | The electrical transport properties of sulphuric acid in a Nation 117 perfluorosulphonic membrane have been studied. Using a mercury cell, the conductivity of the membrane was determined by ac impedance measurements as a function of the degree of swelling and of the amount of sorbed species. The excellent penmselectivity of the Nation 117 membrane to protons was confirmed. By means of radiotracer measurements, the transport number of chemical species bearing a sulphur atom was determined; it was lower than 2% regardless of the amount of sorbed acid or the applied current density. The electro-osmotic flux of water was measured by means of an electro-electrodialysis device. The coefficient of the first dissociation step of molecular sulphuric acid to HSO-4 within the membrane was calculated as a function of the amount of sorbed acid species; it was found to be less than those observed for hydrohalogenic acids. This dissociation coefficient decreased from 0.42 to 0.22 when the concentration of the sorbed sulphuric acid varied from 0.005 to 0.16 mole per sulphonic site. © 1991. |
