Short Poster Lecture
Novel processing routines for ceramic/organic biomimetics have been developed, enabling the production of macro-sized 3D components and the design of materials with multiple levels of hierarchy. The selected building blocks are spherical nanoparticles, grafted with oleic acid, self-assembled into superlattices. The formation of supercrystals leads to the minimization of the organic content, and thus to improved mechanical behavior. A sequence of pressing and heat treatment finalizes the process, by shaping the material into bulk pellets and inducing its strengthening via crosslinking of the organic ligand. The resulting composites present an exceptional combination of isotropic properties, with modulus, hardness and strength up to 114 GPa, 4 GPa and 630 MPa, respectively. The manufacturing routine has been fine-tuned and additional processing technologies have been explored. In particular, spark plasma sintering has turned out to be a promising tool to achieve fast net-shaping of bulk pellets with minimized defects and introduction of multi-functionality. These nanocomposites do not serve only as model system for ultra-strong and hard bioinspired materials, but also as building blocks for material structures with increasing hierarchical levels. By coating supercrystalline micro-sized powders with a polymeric layer and applying an additional pressing step, nacre-mimetics are developed.