Morphology control and shape evolution in 3D hierarchical superstructures

Hierarchical structures, in which structure is generated and controlled simultaneously at different size scales, have attracted increasing attention due to their potentials in both theoretical research and practical applications. In this review, a non-classical crystallization mechanism is discussed for their possibilities in morphology control of hierarchically-structured materials. Differently, this crystallization route is not based on the attaching and detaching of monomers as happened in the classical case, but through the self-organization of preformed building blocks as nanosized subunits, whose oriented attachment leads to mesocrystals with favorable morphology and texture. Representative materials including both inorganic and organic crystals are reported with possible mechanisms proposed. Synthetic protocols based on this mechanism provide unique inspirations for materials design and could be applied to morphological and structural control of new materials with optimized functions.