The adsorption thermodynamics and interfacial speciation of several di- and trivalent metal cations are studied at the silica/water and iron oxide/water interfaces using second harmonic generation.  Specifically, the ?3 technique is employed to quantify binding constants, absolute number densities, and interfacial charge densities of several ions adsorbing to these interfaces.  We also examine the relationship between the measured adsorption free energies and the electric double layer interfacial potential at different electrolyte concentrations to elucidate the charge state and possible binding pathways for different metal ions at the silica/water and hematite/water interface.  Using this highly sensitive surface-specific technique, it was found that the charge states of adsorbed metal ions differ from those in the bulk aqueous environment. The implications for geochemical transport and environmental fate of metal contaminants are discussed.

Studying the adsorption of metal ions to mineral oxide/water interfaces using second harmonic generation

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.