Solvent accessibility and hydrophobicity in the adsorption of alkylammonium cations at air/water and Hg/water interfaces. Part 1. Behavior at the air/water interface in relation to hydration properties

Abstract

By means of adsorption and surface-potential studies on a series of R4−nN+Hn perchlorates at the air/water interface, the role of hydrophobic and hydrophilic interaction in the adsorption and ion distribution of these salts near the air/water interface is examined. While the adsorption of the alkylamine ions increases as n decreases from three to zero, inclusive, the surface-potential change accompanying the adsorption decreases. This effect is interpreted in terms of opposing hydrophilic, electrostatic and hydrophobic interactions between the organic ion and water near the liquid surface, leading to a progressive change of double-layer ion distribution. In Part II, comparative studies of the same series of compounds at the Hg/water interface are reported.