Self-assembly of uniform polyhedral silver nanocrystals into densest packings and exotic superlattices
Self-assembly of uniform polyhedral silver nanocrystals into densest packings and exotic superlattices
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DOI：
10.1038/nmat3178
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发表时间：
2012-02-01
期刊：
影响因子：
41.2
通讯作者：
Yang, Peidong
中科院分区：
文献类型：
--
作者：
Henzie, Joel;Gruenwald, Michael;Yang, Peidong
了解多面体如何堆积成扩展排列，对于设计和发现所有长度尺度的晶体材料都是不可或缺的(1-3)。在列举和表征多面体形状的堆积(4-6)以及多面体纳米晶体自组装成有序超结构(7-9)方面已经取得了很大进展。然而，将多面体纳米晶体自组装成最密集的堆积需要精确控制颗粒形状(10)、多分散性(11)、相互作用和驱动力(12)。在这里，我们通过实验和计算机模拟表明，一系列纳米级的银多面体可以自组装成它们推测的最密集的堆积(6)。当用吸附聚合物钝化时，多面体表现为准硬粒子，并通过沉淀组装成毫米尺寸的三维超晶。我们还表明，通过在溶液中通过过量的聚合物诱导耗尽吸引，八面体形成了具有复杂螺旋图案的奇异超结构，而不是最密集的Minkowski晶格(13)。这种大规模的银超晶体可能有助于设计可伸缩的三维等离子体超材料，用于传感(14，15)、纳米光子学(16)和光催化(17)。
Understanding how polyhedra pack into extended arrangements is integral to the design and discovery of crystalline materials at all length scales(1-3). Much progress has been made in enumerating and characterizing the packing of polyhedral shapes(4-6), and the self-assembly of polyhedral nanocrystals into ordered superstructures(7-9). However, directing the self-assembly of polyhedral nanocrystals into densest packings requires precise control of particle shape(10), polydispersity(11), interactions and driving forces(12). Here we show with experiment and computer simulation that a range of nanoscale Ag polyhedra can self-assemble into their conjectured densest packings(6). When passivated with adsorbing polymer, the polyhedra behave as quasi-hard particles and assemble into millimetre-sized three-dimensional supercrystals by sedimentation. We also show, by inducing depletion attraction through excess polymer in solution, that octahedra form an exotic superstructure with complex helical motifs rather than the densest Minkowski lattice(13). Such large-scale Ag supercrystals may facilitate the design of scalable three-dimensional plasmonic metamaterials for sensing(14,15), nanophotonics(16) and photocatalysis(17).