A major challenge in designing and making potentially valuable nanostructures is to find suitable ways to effectively tune their properties and function. Recent work in our lab has demonstrated a powerful strategy to engineer the morphology and properties of metal chalcogenide 3-D nanostructured assemblies prepared by sol-gel methods. Here we show that by altering the shape of CdSe building blocks from dot to rod, the morphology of the gel can be altered from colloidal to polymeric, and this morphology is retained throughout the supercritical drying step to produce aerogels. Notably, the polymeric (rod) aerogel has twice the surface area of the colloidal (dot) aerogel, and while both materials almost fully maintain the degree of quantum confinement of the building blocks (a phenomenon attributed to the low dimensionality of the framework) the rod aerogel monoliths demonstrate significantly higher quantum yields. Rheological studies of aerogel-PDMS (polydimethylsiloxane) composites indicate that the rod aerogel structure is stronger than the dot aerogel, and the reinforcement is due to the structure of the gel, not the particle geometry. Finally, in addition to dots and rods, the morphological consequences of CdSe branched and hyperbranched nanoparticles on resultant aerogels will also be discussed.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2008: Materials, Fabrication, Particles, and Characterization – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: June 1, 2008
Pages: 316 - 319
Industry sector: Advanced Materials & Manufacturing
Topics: Composite Materials