Surface phase diagrams: evidence of molecular arrangements at the aqueous-solution/solid interface.

Surface state changes described as phase transitions or simple molecular rearrangements have become a key issue in modern science. Indeed, they have an impact on the development of numerous (nano)technologies; they are also involved in biochemical and chemical mechanisms at the molecular level and also in environmental phenomena. At last, they have been at the origin of flourishing statistical descriptions that have illuminated new and very interesting aspects of surface behaviors.

Adsorption mechanisms of carbofuran on silica: structure, kinetics, and solubility influence.

The adsorption processes of carbofuran from solutions in pure water onto silica (Aerosil 200) have been determined in order to bring greater coherence to previous results obtained directly on soils. Adsorption isotherms and their evolution with temperature reveal that adsorption is generally weak, increases with temperature, and does so significantly with concentration when the solubility limit is approached. Kinetics of dissolving, of adsorption on silica, and of desorption all obey an irreversible two-compartment model.