Chinese Academy of Sciences (CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
Department of Chemical and Biomolecular Engineering, University of Maryland, Maryland, 20742, USA.
Nat Commun. 2017 Nov 10;8(1):1410. doi: 10.1038/s41467-017-01111-4.
Nanoparticle self-assembly promises scalable fabrication of composite materials with unique properties, but symmetry control of assembled structures remains a challenge. By introducing a governing force in the assembly process, we develop a strategy to control assembly symmetry. As a demonstration, we realize the tetragonal superlattice of octagonal gold nanorods, breaking through the only hexagonal symmetry of the superlattice so far. Surprisingly, such sparse tetragonal superstructure exhibits much higher thermostability than its close-packed hexagonal counterpart. Multiscale modeling reveals that the governing force arises from hierarchical molecular and colloidal interactions. This force dominates the interactions involved in the assembly process and determines the superlattice symmetry, leading to the tetragonal superlattice that becomes energetically favorable over its hexagonal counterpart. This strategy might be instructive for designing assembly of various nanoparticles and may open up a new avenue for realizing diverse assembly structures with pre-engineered properties.
纳米粒子自组装有望大规模制造具有独特性能的复合材料，但组装结构的对称性控制仍然是一个挑战。通过在组装过程中引入控制力，我们开发了一种控制组装对称性的策略。作为一个演示，我们实现了八边形金纳米棒的四方超晶格，突破了迄今为止四方超晶格的六边形对称性。令人惊讶的是，这种稀疏的四方超结构表现出比其紧密堆积的六边形对应物更高的热稳定性。多尺度建模揭示了控制力源于层次化的分子和胶体相互作用。这种力主导了组装过程中涉及的相互作用，并决定了超晶格的对称性，导致四方超晶格在能量上优于其六边形对应物。这种策略可能对设计各种纳米粒子的组装具有启示性，并可能为实现具有预设计性能的各种组装结构开辟新途径。
