Mass mapping with the scanning transmission electron microscope.

The simple combination of tritopic pyridine donor linkers with a new flexible acceptor "clip" in a 2:3 stoichiometric ratio generates three-dimensional M3L2 cages which possess large cavities in essentially quantitative yields.

Macromolecular Substances↗

PubMed2006

Dispersion of pristine single-walled carbon nanotubes in water by a thiolated organosilane: application in supramolecular nanoassemblies.

We report a novel technique to disperse pristine single-walled carbon nanotubes in water by ultrasonication in the presence of a thiolated organosilane and subsequent ultracentrifugation. As revealed by the sharp features in the visible range of the absorption spectrum and by transmission electron microscopy, the collected supernatant fraction was composed of small bundles of nanotubes coated by a thin layer of organosilane molecules. We hypothesized and demonstrated that the organosilane adsorbed onto the nanotubes through the thiol group leaving the silane group extruding out. The pristine properties of the nanotubes and the versatile chemistry available for sol-gel materials make the reported dispersed nanotubes an excellent scaffold for the realization of supramolecular nanoassemblies suitable for different applications. As examples, we decorated them with silica nanobeads, by using a water-in-oil nanoemulsion system, and with gold nanoparticles, by a previous derivatization with a second layer of thiolated organosilane providing exposed thiol groups.

Macromolecular Substances↗

PubMed2006

Shapes of embedded minimal surfaces.

Surfaces that locally minimize area have been extensively used to model physical phenomena, including soap films, black holes, compound polymers, protein folding, etc. The mathematical field dates to the 1740s but has recently become an area of intense mathematical and scientific study, specifically in the areas of molecular engineering, materials science, and nanotechnology because of their many anticipated applications. In this work, we show that all minimal surfaces are built out of pieces of the surfaces in Figs. 1 and 2.

Macromolecular Substances↗