COLL 71 |
| Xiao-Min Lin1, Suresh Narayanan2, and Jin Wang2. (1) Materials Science Division, Chemistry Division and Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, (2) Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 |
| Self-assembly is an important process nature adopts to form much of the physical world around us. Many supermolecular systems use nanoscale building blocks, such as proteins, to form complex macroscopic structures. Self-assembly of chemically synthesized monodispersed colloidal nanocrystals can provide a simple model system to mimic this process. Understanding the nanoscale self-asembly dynamics requires in situ measurements with high spatial and temporal resolution. We describe here the first in situ small-angle x-ray scattering measurement of the formation of a highly ordered nanocrystal superlattice monolayer during colloid droplet evaporation. We show that the kinetics of the droplet evaporation determines the dimensionality of the superlattices. Above a critical evaporation rate, a two-dimensional nanocrystal superlattice monolayer can preferentially form at the liquid-air interface, whereas under low evaporation condition, 3D superlattice forms inside the colloidal droplet. |
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Nanoscience and Nanotechnology
2:00 PM-5:15 PM, Sunday, March 28, 2004 Marriott -- Grand Ballroom K, Oral
Division of Colloid and Surface Chemistry |