Self-assembly of nano-building blocks: towards ceramic nanocomposites with exceptional mechanical properties
In the strive to produce hierarchical materials with an outstanding combination of mechani-cal properties, new materials based on the self-assembly of nano building blocks have been developed and characterized from a variety of perspectives. The constitutive effect is based on a highly ordered, supercrystalline structure of ceramic nanoparticles bound together via soft organic molecules. The material is strengthened via a thermal induced crosslinking of their surface ligands . Moreover, the organo-functionalization and the interaction with the surrounding medium during the solvent evaporation induced self-assembly has resulted in a controllable way to tune the micromechanical behavior of the obtained 3D bulk struc-ture . Recently, the size and shape of the supercrystalline structures have been further controlled in an emulsion based self-assembly technique allowing the obtention of wet pro-cessible, spherical supercrystalline micro-building blocks. These structures allowed further assessment of their mechanical behavior via in situ SEM compression tests of single spheres. Furthermore, the building blocks can be processed into higher hierarchical level materials by adding a polymeric shell e.g. via emulsion polymerization, spray drying, and spouted bed to establish further hierarchical level with improved final properties.
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