DE-FG02-06ER15364: Final Technical Report Nanoscale Reactivity of Clays, Clay Analogues (Micas), and Clay Minerals

[摘要] The project objectives were to determine the nanoscale to molecular scale structure of the interface between muscovite mica and aqueous solutions containing various sorbates and to explore systematics that control the incorporation of inorganic and organic chemical components during aging of nanoparticles of iron-oxides and aluminosilicate clays. The basal surface of phyllosilicates is a primary sorbent of environmental contaminants, natural organic matter, and nutrients. Micas are also superb atomically-flat substrates used in materials science and surface physics applications. We applied X-ray scattering techniques using high brilliance synchrotron radiation to investigate molecular-scale details of mica’s interface structure in solutions containing common and toxic cations, anions, and natural organic molecules. Nanoparticles are ubiquitous in the environment and have a high capacity for sorbing contaminants through the combined effects of their high surface areas and pH-dependent surface charge. Aging of nanoparticles from metastable to stable phases can be inhibited by sorption of nonstructural components, but exact mechanisms are unknown. We synthesized Fe-oxides and aluminosilicate clay minerals from aqueous solutions in the presence of selected anions, and organic molecules, and quantified the uptake of these additives during aging and some implications for nanoparticle formation.

[发布日期] 2008-07-03

[学科分类] 地球科学(综合)

[关键词] ADDITIVES;AGING;ANIONS;AQUEOUS SOLUTIONS;CATIONS;CLAYS;IRON OXIDES;MICA;MUSCOVITE;NUTRIENTS;ORGANIC MATTER;PHYSICS;SCATTERING;SORPTION;SUBSTRATES;SURFACE AREA;SYNCHROTRON RADIATION muscovite;mica;adsorption;natural organic matter;X-ray reflectivity;resonant anomalous X-ray reflectivity