Mesoscale assembly

In contrast to mesoscale assemblies, mesocrystals are considered intermediates on the formation pathway to single crystals (Colfen and Yu, 2005). The full growth mechanism has been reported for very few mesocrystals, two of... 

The nonhydrolytic M—O—M bond formation via ester elimination between metal alkoxides and carboxylic acids is a well-known approach in sol-gel chemistry. In this direction, titanium -butoxide and acetic acid were used for the nonhydrolytic synthesis of anatase Ti02 nanopartides at 100 °C [92]. Moreover, spindle-shaped nanoporous anatase Ti02 mesocrystals with a single-crystal-like structure and tunable sizes were synthesized in the tetrabutyl titanate and acetic acid system without any additives imder solvothermal conditions [93]. A complex mesoscale assembly process, involving oriented aggregation of tiny anatase nanocrystals and entrapment of in situ produced butyl acetate as a porogen, was proposed for the formation of the mesocrystals. They exhibited a good performance as anode material for lithium ion batteries [93]. 

The use of DNA as a template to fabricate mesoscale structures was also demonstrated in a recent work of Torimoto and coworkers. They used preformed, positively charged 3-nm CdS nanoparticles with a thiocholine-modified surface to be assembled into chains by using the electrostatic interaction between positively charged nanoparticle snr-faces and the phosphate groups of DNA. As determined by TEM analysis, the CdS nanoparticles were arranged in a qnasi-one-dimensional dense packing. This revealed interparticle distances of about 3.5 nm, which is almost equal to the height of one helical tnm of the DNA double strand [98]. 

Golfen, H. and Mann, S. (2004) Higher-order organization by mesoscale self-assembly and transformation of hybrid nanostructures. Angewandte Chemie-Intemational Edition, 42, 2350-2365. 

The use of magnetism to align nanoscale-mesoscale objects has been previously reported by Meyer and Whitesides. Meyer used magnetism to self-assemble... 

A. O Riordan, R Delaney, and G. Redmond, Field configured assembly Programmed manipulation and self-assembly at the mesoscale. Nano Lett. 4(2), 761-765 (2004). 

Fig. 37 Schematic illustrating the organization of nanoparticles in two- (2-D) and three-(3-D) dimensional gradients and the dual character of such assemblies - continuous on mesoscale and discontinuous on micro- and nanoscales. (Reproduced with permission from [140])...

There are nevertheless a number of recent indicators that the biotechnological challenge has fostered the chemists creativity. Some of them are able to self-assemble components, thanks to a clever use of surfactants as supramolecular templates. Inorganic complex structures presenting a variety of interesting shapes such as discs or helix can be obtained at a mesoscale or in some cases at the macroscopic level. [28]... 

For instance, H.Yang, N. Coombs, G.A. Ozin, Morphogenesis of shapes and surface patterns in mesoporous silica, Nature 386 (1997) 692-695 N. Bowden, A. Ter-fort, J. Carbeck, G. Whitesides, Self-assembly of mesoscale objects into ordered two-dimensional arrays, Science TIB (1997) 233-235. 

In this chapter, supramolecular chemistry related to developments in materials fabrication and functionalization at the mesoscale are discussed, with an emphasis on those systems based on organic-inorganic hybrid structures. The contents of this chapter are classified into (1) supramolecular chemistry within mesoscopic media, (2) supramolecular assembly at the mesoscale, and (3) supramolecular materials at the mesoscale. Despite this classification these topics have considerable similarities. 

Precursors with a distinctive tendency to undergo molecular self-assembly processes (i.e., even without the presence of SDAs), for instance driven by n-stacking or hydrogen bonds, also facilitate the onset of mesoscale periodicity in templated synthesis approaches. 

Despite these difficulties, mesoscale self-assembly of inorganic materials holds promise. In fact, it is believed that the importance of self-assembly in the manufacturing of electronics, photonics, optics, and robotics mesoscale components could conceivably supersede its importance in the molecular and nanoscale sciences. Some hybrid organic—inorganic systems have attracted attention because... 

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

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