Synthesis of heterodimeric sphere-prism nanostructures via metastable gold supraspheres

COLL 302

Rafal Klajn, rafal@northwestern.edu, Department of Chemical Engineering, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208 and Bartosz A. Grzybowski, Department of Chemical Engineering, Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208.
Spherical assemblies of gold nanoparticles (supraspheres) undergo a thermally-induced, "stoichiometric" transformation into heterodimeric gold nanostructures comprising spherical and prismatic domains. By controlling the reaction time, it is possible to isolate various structures differing in the relative sizes and shapes of the two domains. Initially, the supraspheres "bud" hexagonal gold prisms, giving rise to stable hexagon-sphere heterodimers. Upon further heating, hexagons grow and evolve into triangles and dodecagons at the expense of the supraspheres. Finally, a mixture of triangular and dodecagonal gold prisms is obtained as the final product. Our experiments indicate that the supraspheres act as "nanoreservoirs" of gold, and that it is possible to regulate dimensions of the prisms by varying the size of the initial supraspheres.

 

Polymer-Nanoparticle Systems: Theory, Simulation, Experiments
9:00 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 227, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008