Structure formation mesocrystals

Figure 5 Hierarchical structure of mesocrystals (A) porous balls of ZnO quantum dots and (B) ellipsoids of ZnO nanorods and their formation mechanism. Panel (A) Distaso et al (2012). Panel (B) KlaumUnzer et al (2014). Reproduced with permission from the Royal Society of Chemistry.

Fig. 16 SEM image of the convex-concave calcite (a) and its proposed formation mechanisms (b). The primary blocks assemble to give flat, pseudo-symmetric mesocrystal structures. When a certain size is exceeded, not only primary platelets, but also amorphous intermediates (spheres) are attracted. By recrystallization of those species, bent crystalline structures without translational order can develop. Reprinted with permission from Wiley-VCH. ...

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]. 

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