Article révisé par les pairs
Résumé : At the mercury electrode and for low charge densities, the capacity curves show a pit which results from the formation of a condensed film of adsorbed adenosine molecules. The width of the capacity pit increases with the concentration of the surfactant. The sudden phase transition between the two superficial structures differing by the spatial arrangement and the mobility of the adsorbed molecules is studied by the potential-step method. The kinetics of condensed phase formation are controlled by a two-dimensional nucleation and growth process. The rate of relaxation measured in function of the final potential presents a maximum whose amplitude increases with organic molecules concentration. In agreement with the fact that the driving force which controls the nucleation process is the difference δΔγ of superficial tension between the final state and the metastable state preceding the relaxation, a meaningful relation between the interfacial tension and the rate of relaxation has been observed at every potential. © 1984.