COLL 519 |
| David J. Burleson and R. Lee Penn. Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455 |
| Nanoparticles have many size-dependent properties (eg., chemical reactivity, electrical, magnetic, and optical properties) that make them exciting for use in various industrial applications such as catalysis or magnetic recording media. A greater understanding of how nanoparticles grow is required in order to 1) better understand how nanoparticles form in the environment and 2) control the growth and, therefore, the final material properties of the nanoparticles. Nanoparticles grow by two main mechanisms: coarsening and aggregation. The growth of goethite (α-FeOOH) nanoparticles from smaller ferrihydrite (Fe5HO8•4H2O) nanoparticles presents a unique situation whereby, under normal aqueous conditions, the growth occurs almost exclusively by oriented aggregation, a special case of aggregation. The dependence of the growth of goethite nanoparticles particles in aqueous suspension on pH and temperature as characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) will be presented. |
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Environmental Colloids
2:00 PM-3:40 PM, Thursday, April 1, 2004 Marriott -- Grand Ballroom H, Oral
Division of Colloid and Surface Chemistry |