Étude des propriétés diélectriques de solutions aqueuses diluées d'électrolytes forts II. Les phénomènes d'electrode

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Abstract
Electrode or polarization effects in alternating fields (frequency range: 10 to 400 kilocycles/sec.) have been investigated using aqueous solutions of KCl, NaCl, KI and BaCl2 at molalities varying from 10−4 to 5.10−3 mole/1000 grs. Blank, unpolished platinum electrodes were used.Under our experimental conditions there was no ionic discharge and adsorption currents could be neglected; electrode effects seemed due exclusively to a relaxation current of the double layer.It was shown that the electrode capacity was independent of the distance between electrodes. The experimental value of the relaxation time of the double layer was considerably larger than that calculated from the known values of the diffusion constants of all ions involved. This may be explained by a lowering of the ionic mobilities in the double layer.The time evolution, both for the total resistance and for the electrode capacitance indicates that there is some irreversible surface phenomenon. This may be partly responsible for the discrepancies between experimental and theoretically predicted results.