纳米粒子的精准组装

纳米材料由于其独特的光、电、磁、力学等性质,成为了构建功能材料与器件的理想基元。实现纳米粒子的精确组装,是探究粒子之间的耦合聚集性质和制备宏观功能器件的基础。但是由于纳米粒子的小尺寸以及在溶液中运动的随机性与复杂性,精准控制纳米粒子组装体的形貌以及在空间中的相对位置仍存在巨大挑战。为了将纳米粒子组装成理想的有序结构,许多控制粒子组装的策略与方法得到发展。本文首先概述了纳米粒子自组装的控制方法与典型形貌,着重分析了影响粒子精准排布的因素与控制方法,并对纳米粒子及其组装体的光学性质与器件应用的最新研究进展进行了讨论,最后对目前纳米粒子精准组装所面临的挑战以及未来发展的方向进行了展望。

The Precise Assembly of Nanoparticles

Nanoparticles (NPs) are ideal building blocks for constructing functional materials and devices due to their unique optical, electronic, magnetic, and mechanical properties. The precise assembly and patterning of NPs to obtain ordered structures are vital to explore the special properties of NPs. The specific configurations of large-scale NP assemblies from two-dimensional (2D) NP patterns to one-dimensional (1D) NP arrays on substrates are considered the ideal platform for many technological devices, such as solar cells, magnetic memory, switching devices, and sensing devices, due to their unique transport phenomena and the cooperative properties of NPs in assemblies. Regulation with high-precision control over the orientation and spatial arrangement of nanoarchitecture is required to achieve the coupling and collecting between NPs and thereby translate the properties of the individual NPs to the functions of the macroscopic materials. Therefore, the development of effective methods to build and implement ordered nanocomposites has been accelerated considerably over the last decade. However, due to the complex physics and thermodynamics of the NP assembly, precise control over the orientation and spatial distribution of nanoassemblies with a large area and high homogeneity remains a challenge. In order to tune the position and shape of the NPs into desired structures, a series of strategies and methods have been proposed and developed. These strategies include manipulation of interparticle physical interactions, modification of NP surface chemistry, effect of external fields, utilization of physically or chemically patterned templates, and application of an inkjet printing technique to achieve the desired level of spatial and orientational control over the assembly of NPs. In this paper, we summarized the typical morphologies and the precise control of the architectures prepared by the NPs self-assembly. The particle density, particle size, and interparticle distance of the NP assemblies were strongly controlled. Then the bottom-up strategies for positioning NPs into desired structures with high resolution and considerable throughput were shown. In addition, we discussed the unique functions and diverse applications of the ordered NP assemblies. Both the strong surface plasmon resonance coupling and directional electron transport between particles were studied, which was of highly significance in the development of many technological devices and of great scientific interest. Finally, we investigated the challenges and opportunities of the precise assembly of NPs, which could provide insight and guidance for the future development of functional nanoassembly devices.