Adsorption-desorption phenomena of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate at a hanging mercury drop electrode

Adsorption-desorption phenomena of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate at a mercury electrode were studied by a.flow injection method with measuring differential capacity-time curves. Adsorption of sodium dodecyl sulfate at -0.2 V is irreversible, while that at the potential more negative than - 0.4 V is reversible. Adsorption of sodium dodecylbenzenesulfonate is irreversible at the potential more positive than -0.8 V. It is reversible at the potential more negative than -1.0 V. From these results, adsorption models for the two surfactants were proposed.