Solvent accessibility and hydrophobicity in the adsorption of alkylammonium cations at air/water and Hg/water interfaces. Part II. Behavior at the Hg/water interface in relation to hydrophobic interactions

Abstract

The adsorption behavior of a series of n-propylammonium ions in which the N+ center has varying accessibility to the solvent, and hence the ions exhibit varying hydrophobicity, is examined at the Hg/H2O interface at various electrode potentials. With the most hydrophobic ion, (n-Pr)4N+, attractive interactions arise in the interphase. An attempt is made to explain this behavior in terms of Gurney hydration co-sphere sharing effects which are significant in 3-dimensional aqueous solutions of R4N+ salts.The surface pressure behavior and Esin and Markov effects are also evaluated.Comparisons are made with the adsorption and surface potential results reported in Part I for the air/water interface.