Multiscale Nanomaterials - From Colloidal Self-Assembly to Macroscale, Functional Materials Systems

Nanoparticle assembly has emerged as a key tool to dictate the arrangement and the collective properties of nanocomposite materials. However, the lack of understanding on the self-assembly itself and the difficulty of controlling the processes involved in a large spectrum of length-scales (from nano to macro) typically leads to defects which scale with the dimensions of the specimen. This ultimately limits their structural integrity and hence their development beyond microscale materials and devices. This dissertation addresses the multiscale challenges which arise during the transition of nanomaterials’ development from small-scale, functional units towards serviceable, macro-scale, engineering components. A novel combination of bottom-up and top-down strategy is presented to fabricate a nature-inspired material design consisting of self-similar, hard, inorganic structures interconnected via soft, organic layers on multiple hierarchy levels. First, this approach allows to understand and control the processes occurring on the atomic to the nanoscale during nanocrystal self-assembly and for the manipulation of nanocrystals’ interfaces. The gained new insights allow to modulate the high concentration of interfaces in nanostructured materials and give the opportunity to tailor the mechanical and functional properties of the developed hybrid materials. Secondly, a new emulsion based strategy is presented which allows to control the microstructure of self-assembled nanocrystals. This technique is further optimized and utilized as a means to precisely control the mesostructure of the intended bioinspired material design. Lastly, the developed nanostructured meso-materials are implemented in a macroscale, multi-hierarchical composite. The overall multiscale approach ultimately allows to create a robust architecture with multifunctional properties fostered through adjustable nanoscale features.