On the kinetics of adsorption and desorption of perchlorate ions in the presence of 3-methyl-isoquinoline at the mercury—aqueous solution interface

Abstract

Coadsorption of perchlorate ions and 3-methyl-isoquinoline molecules at the mercury—aqueous solution interface results in the formation of a condensed film. The process of ClO − 4 incorporation (or removal) is very slow. Characteristic relaxation times (about 10 −2 s) are several orders of magnitude larger than values typical of ion adsorption at a mercury—solution interface which is free from organic surfactant. The relationships between the rate of the process, the electrode potential and the amount of adsorbed ClO − 4 ions are determined and discussed. The results indicate that the rate of the overall process is controlled by a slow adsorption (or desorption) step whose kinetics are consonant with an isotherm of the Temkin type.