DWI-Leibniz-Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
VTT Technical Research Centre of Finland, Tietotie 2, FI-02044 Espoo, Finland.
Nat Commun. 2015 Jan 20;6:5967. doi: 10.1038/ncomms6967.
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.
珍珠层仿生材料作为机械高性能和功能材料具有巨大的应用前景。在这里，我们通过使用具有三个数量级（25-3500）纵横比的合成纳米黏土，展示了自组装聚合物/纳米黏土珍珠层仿生材料的机械和功能特性的重大进展。我们建立了结构形成、纳米结构化、变形机制和机械性能之间的综合关系，作为纳米黏土纵横比的函数，并通过水合作用调节软相的粘弹性。即使对于低纵横比的纳米片，也可以获得高度有序的大规模珍珠层仿生材料，并表现出非常高的韧性的显著的非弹性变形，而由超大纳米片形成的材料则表现出优异的刚度和强度，这以前只能通过高度交联的材料来实现。关于功能，我们报告了以前不可能的玻璃状透明度，以及极好的气体阻隔性能，远远超过了以前基于天然纳米黏土的珍珠层仿生材料。我们的研究能够为未来高性能珍珠层仿生材料的合理设计提供指导，并为环保、透明、自立和高强度的先进阻隔材料开辟道路。
