Nanocrystals giant

Magic Nuclearity Giant Clusters of Metal Nanocrystals Formed by Mesoscale Self-Assembly... 

Figure 1. Schematic illustration of a (Mj5) 5 giant cluster. The structure of one of the nanocrystals is shown.

Figure 3. TEM image of Pd5(,i uanocrystals forming giant clusters. The numbers correspond to the proposed number of nanocrystal shells, n.

Figure 5. Giant clusters of different magic nuclearities, (Pd the circles corresponding to the diameters of the clusters calculated on the basis of the effective volume of an individual nanocrystal.

Mesoscale self-assembly of metal nanocrystals into ordered arrays and giant clusters... 

Figure 8.23. TEM micrograph showing the giant clusters comprising Pd561 nanocrystals. The sample for TEM was prepared by the slow evaporation of a PVP- Pd561 hydrosol. (Reproduced with permission from reference [49].)...

The giant clusters could be reproducibly formed starting from Pd561 nanocrystals in water, ethanol and ethanol-water mixtures and from sols with very different concentrations of the nanocrystals. It is possible that the formation of the giant clusters is facilitated by the polymer shell that encases them. Unlike Pd nanocrystals coated with alkanethiols, which self-assemble to form ordered arrays, the polymer shell effectively magnifies the facets of the metallic core, thereby aiding a giant assembly of the nanocrystals. The surface properties of the polymer-coated nanocrystals are clearly more favorable in that the interparticle interaction becomes sufficiently attractive. 

Fig. 4.21. TEM micrograph showing the giant enclosed in circles whose diameters correspond clusters comprising Pdsgi nanocrystals. Sample to magic numbers. The n and the numbers in for TEM was prepared by the slow evaporation the parenthesis indicate the number of of a PVP-Pdssi hydrosol. Giant clusters are nanocrystals and closed-shells respectively.

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