title: Organically linked iron oxide nanoparticle supercrystals with exceptional isotropic mechanical properties.
abstract: It is commonly accepted that the combination of the anisotropic shape and nanoscale dimensions of the mineral constituents of natural biological composites underlies their superior mechanical properties when compared to those of their rather weak mineral and organic constituents. Here, we show that the self-assembly of nearly spherical iron oxide nanoparticles in supercrystals linked together by a thermally induced crosslinking reaction of oleic acid molecules leads to a nanocomposite with exceptional bending modulus of 114 GPa, hardness of up to 4 GPa and strength of up to 630 MPa. By using a nanomechanical model, we determined that these exceptional mechanical properties are dominated by the covalent backbone of the linked organic molecules. Because oleic acid has been broadly used as nanoparticle ligand, our crosslinking approach should be applicable to a large variety of nanoparticle systems.
authors.affiliation: Institute of Advanced Ceramics, Hamburg University of Technology, Denickestrasse 15, D-21073 Hamburg, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Dreyer
authors.affiliation: Institute of Physical Chemistry, Hamburg University, Grindelallee 117, D-20146 Hamburg, Germany.
authors.forename: Artur
authors.initials: A
authors.lastname: Feld
authors.affiliation: Institute of Physical Chemistry, Hamburg University, Grindelallee 117, D-20146 Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kornowski
authors.affiliation: Institute of Advanced Ceramics, Hamburg University of Technology, Denickestrasse 15, D-21073 Hamburg, Germany.
authors.forename: Ezgi D
authors.initials: ED
authors.lastname: Yilmaz
authors.affiliation: DESY NanoLab, Deutsches Elektronensynchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany.
authors.forename: Heshmat
authors.initials: H
authors.lastname: Noei
authors.affiliation: Institute of Physical Chemistry, Hamburg University, Grindelallee 117, D-20146 Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyer
authors.affiliation: Electron Microscopy Unit, Hamburg University of Technology, Eißendorfer Strasse 42, D-21073 Hamburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Krekeler
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: Chengge
authors.initials: C
authors.lastname: Jiao
authors.affiliation: DESY NanoLab, Deutsches Elektronensynchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany.|Physics Department, Hamburg University, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stierle
authors.affiliation: Institute of Physical Chemistry, Hamburg University, Grindelallee 117, D-20146 Hamburg, Germany.|Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Abetz
authors.affiliation: Institute of Physical Chemistry, Hamburg University, Grindelallee 117, D-20146 Hamburg, Germany.|Center for Applied Nanotechnology, Grindelallee 117, D-20146 Hamburg, Germany.|Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Horst
authors.initials: H
authors.lastname: Weller
authors.affiliation: Institute of Advanced Ceramics, Hamburg University of Technology, Denickestrasse 15, D-21073 Hamburg, Germany.
authors.forename: Gerold A
authors.initials: GA
authors.lastname: Schneider
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