Learn More
Crystalline surfaces of common rock-forming minerals are likely to have played several important roles in life's geochemical origins. Transition metal sulfides and oxides promote a variety of organic reactions, including nitrogen reduction, hydroformylation, amination, and Fischer-Tropsch-type synthesis. Fine-grained clay minerals and hydroxides facilitate(More)
Correlations among experimentally determined standard partial molal thermodynamic properties of inorganic aqueous species at 25 degrees C and 1 bar allow estimates of these properties for numerous monatomic cations and anions, polyatomic anions, oxyanions, acid oxyanions, neutral oxy-acid species, dissolved gases, and hydroxide complexes of metal cations.(More)
A large number of aqueous metal complexes contribute significantly to hydrothermal, metamorphic, and magmatic processes in the crust of the Earth. Nevertheless, relatively few thermodynamic data other than dissociation constants (K) for a few dozen of these complexes have been determined experimentally at elevated temperatures and pressures. The(More)
Hydrous ferric oxide (HFO) and titanium dioxide exhibit similar strong attachment of many adsorbates including biomolecules. Using surface complexation modeling, we have integrated published adsorption data for glutamate on HFO over a range of pH and surface coverage with published in situ ATR-FTIR studies of glutamate speciation on amorphous titanium(More)
Water is a major component of fluids in the Earth's mantle, where its properties are substantially different from those at ambient conditions. At the pressures and temperatures of the mantle, experiments on aqueous fluids are challenging, and several fundamental properties of water are poorly known; e.g., its dielectric constant has not been measured. This(More)
Nucleic acids, the storage molecules of genetic information, are composed of repeating polymers of ribonucleotides (in RNA) or deoxyribonucleotides (in DNA), which are themselves composed of a phosphate moiety, a sugar moiety, and a nitrogenous base. The interactions between these components and mineral surfaces are important because there is a tremendous(More)
Metal adsorption data over a range of surface coverages typically are characterized by curvilinear metal adsorption isotherms. These isotherms generally have a slope of 1 at low surface coverage and a shallower slope at higher surface coverages. The curvature of metal adsorption isotherms with increasing surface coverage is frequently interpreted in terms(More)
Dihydroxyphenylalanine (DOPA) and similar molecules are of considerable interest in studies of bioadhesion to minerals, solar cells involving titanium dioxide, and biomedical imaging. However, the extent and mechanisms of DOPA adsorption on oxides in salt solutions are unknown. We report measurements of DOPA adsorption on well-characterized rutile (α-TiO₂)(More)
We studied the adsorption of short single-stranded deoxyribonucleic acid (ssDNA) oligomers, of approximately 30 nucleotides (nt) in length, of varying sequence, adenine+guanine+cytosine (AGC) content, and propensity to form secondary structure, to equal surface area samples of olivine, pyrite, calcite, hematite, and rutile in 0.1M NaCl, 0.05M pH 8.1 KHCO(3)(More)
The adsorption configuration of organic molecules on mineral surfaces is of great interest because it can provide fundamental information for both engineered and natural systems. Here we have conducted surface-enhanced Raman spectroscopy (SERS) measurements to probe the attachment configurations of DOPA on nanorutile particles under different pH and surface(More)