title: Nacre-mimetics with synthetic nanoclays up to ultrahigh aspect ratios.
abstract: Nacre-mimetics hold great promise as mechanical high-performance and functional materials. Here we demonstrate large progress of mechanical and functional properties of self-assembled polymer/nanoclay nacre-mimetics by using synthetic nanoclays with aspect ratios covering three orders in magnitude (25-3,500). We establish comprehensive relationships among structure formation, nanostructuration, deformation mechanisms and mechanical properties as a function of nanoclay aspect ratio, and by tuning the viscoelastic properties of the soft phase via hydration. Highly ordered, large-scale nacre-mimetics are obtained even for low aspect ratio nanoplatelets and show pronounced inelastic deformation with very high toughness, while those formed by ultralarge nanoplatelets exhibit superb stiffness and strength, previously only reachable for highly crosslinked materials. Regarding functionalities, we report formerly impossible glass-like transparency, and excellent gas barrier considerably exceeding earlier nacre-mimetics based on natural nanoclay. Our study enables rational design of future high-performance nacre-mimetic materials and opens avenues for ecofriendly, transparent, self-standing and strong advanced barrier materials.
authors.affiliation: DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
authors.forename: Paramita
authors.initials: P
authors.lastname: Das
authors.affiliation: VTT Technical Research Centre of Finland, Tietotie 2, FI-02044 Espoo, Finland.
authors.forename: Jani-Markus
authors.initials: JM
authors.lastname: Malho
authors.affiliation: DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
authors.forename: Khosrow
authors.initials: K
authors.lastname: Rahimi
authors.affiliation: Friedrich-Schiller-University Jena, Lessingstrasse 8, D-07743 Jena, Germany.
authors.forename: Felix H
authors.initials: FH
authors.lastname: Schacher
authors.affiliation: DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
authors.forename: Baochun
authors.initials: B
authors.lastname: Wang
authors.affiliation: DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
authors.forename: Dan Eugen
authors.initials: DE
authors.lastname: Demco
authors.affiliation: DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Walther