PHYS 433 |
| Ligand-passivated colloidal nanoparticles are novel building-block materials whose physical and chemical properties can be designed independently. We have developed a synthetic route for making small thiol-passivated silver nanoparticles in aerobic conditions and where core and shell are synthesized separately. Large-angle XRD confirms the presence of a metallic Ag core with a diameter of ~4 nm. These nanoparticles have a strong tendency to crystallize into micron- to millimeter-sized 3D superlattices, suggesting that a large fraction of our product may be monodisperse. Optical images show platelets and needle-like superlattice morphologies. Small-angle XRD shows up to 28 orders of reflections for these superlattices, with d-spacings that depend on the thiol chain length. We have found that superlattices composed of thiol-capped nanoparticles are quite soft whereas those composed of nanoparticles without thiol ligands are brittle. We will also discuss the relationship between chain length and superlattice structure. |
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PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Sci-Mix
Division of Physical Chemistry |