The controlled self-assembly of nano-particles has the unique opportunity to tailor material properties via enhanced collective properties by new field coupling within the ordered arrays over the micro- to macroscopic size range of the aggregate. Such aggregates called mesocrystals are made by non-classical particle mediated crystallization and can consequently form significantly different crystalline symmetry than those of their constituents. The physical properties of these newly formed crystalline forms originate from their special structure, which is, in some cases, impossible for a crystal of similar size.
In this work, the authors demonstrate the simultaneous self-assembly of platinum and iron oxide nanocubes into micrometre sized 3D mesocrystals via gas-phase diffusion technique. By the addition of minor amounts of a secondary particle type tailored to nearly identical size, shape and surface chemistry, it becomes possible to promote random incorporation of foreign particles into a self-assembling host lattice. Nanoparticles sizes, incorporation ratios, symmetry and orientation was determined via microscopy techniques and small-angle x-ray scattering performed at the cSAXS beamline. The 20-40 µm sized binary mesocrystals revealed a long-range ordering on the atomic scale throughout the crystal while showing clear evidence that the material consists of individual building blocks.
This pioneering work opens the door to a new range of complex multi-component binary or even ternary superstructures with novel features, packing order as well as physical and chemical properties that are yet to be discovered.
Contact
Helmut Cölfen
Department of Chemistry
Physical Chemistry
University of Konstanz
Universitätsstraße 10
Helmut.Coelfen@uni-konstanz.de
Christian Appel
Laboratory of Macromolecules and Bioimaging
Photon Science Division PSD
Paul Scherrer Institut
Forschungsstrasse
Villigen
christian.appel@psi.ch
Original Publication
Jenewein Christian, Jonathan Avaro, Christian Appel, Marianne Liebi, and Helmut Coelfen. 2021. ‘3D Binary Mesocrystals from Anisotropic Nanoparticles’. Angewandte Chemie International Edition, 10. https://doi.org/10.1002/anie.202112461
