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。

Regulating droplet impact symmetry by surface engineering

Droplet impact on solid surfaces is essential both in nature and industry.Precisely regulating the dynamic behavior of droplet impact is of great significance for energy harvesting,anti-icing,inkjet printing,pesticide spraying,and many other fields.Various rebounding behaviors(deposition,rebounding,rotation,instability control,and so on)and rebounding intrinsic parameters(such as contact time)after droplets impacting on solid surfaces can be regulated by surface engineering.This paper reviews the advances in regulating droplet impact behavior from the perspective of symmetry by modifying solid surfaces from the following aspects:chemical modification and physical structure regulation,in which the symmetry is discussed from mirror symmetry and rotational symmetry.Firstly,the symmetry of the droplet impact dynamics and its influencing factors are introduced.Then the modulation of droplet impact symmetry,using homogeneous and heterogeneous chemically modified solid surfaces,is summarized.The following presents the influence of physical structures,from micro to macro scale compared to the droplet size,on the droplet impact symmetry.Finally,the future challenges and opportunities of the droplet impact behavior regulation are discussed。

基于各向异性表面的液滴驱动

驱动液滴实现各种动态行为在生物医学、微流控、痕量检测等领域具有重要应用。液滴的驱动主要依赖于对液滴不同位置受力的调节。具有浸润性差异或结构差异的各向异性表面,在对液滴进行驱动时具有操作简便、节约能源等优势,逐渐成为液滴操控领域的研究热点之一。本文结合本课题组的研究工作,对近年来利用各向异性表面驱动液滴的相关研究进行了综述。首先,分析了各向异性表面驱动液滴的基本原理。依据制备方法的不同,将各向异性表面分为浸润性各向异性表面、结构各向异性表面和协同各向异性表面三类,分别归纳了其常见制备方法和在液滴驱动领域的主要应用。最后,本文对各向异性表面驱动液滴的局限性和发展方向进行了总结和展望。

Precise Droplet Manipulation Based on Surface Heterogeneity

The control of droplet behavior has been investigated for several centuries due to its universality and significance in nature,daily life,and industrial applications.Diverse strategies have been developed and employed to regulate droplet behavior,and great progress has been achieved such as accelerated droplet bouncing,controlled droplet dispensing,and enhanced droplet adhesion.Compared with the strategies utilizing external fields including magnets,heat,light,and electricity as well as various topological structures,the heterogeneous wettability surface provides a facile and efficient way to manipulate droplet behavior and thus has aroused increasing research interest in many fields.The heterogeneous wettability substrate integrates wettable and less wettable regions onto an individual surface,with rational design and a geometrical arrangement.Therefore,it shows more precise,diverse,and controllable interactions with droplets than homogeneous surfaces.In addition to confining the droplet position and morphology and regulating the droplet dynamics,the nonuniformity in wettability can induce a difference in electrical conductivity,nucleation energy barriers,and so forth,which greatly extends its application in the fields of functional materials deposition and device fabrication.In this Account,recent progress in the precise droplet manipulation based on heterogeneous wettability is summarized.First,the principle of droplet control by a heterogeneous surface and the development of the green printing technique based on this principle are introduced.Then the droplet manipulation,categorized as droplet patterning,droplet isolation,and droplet dynamics,is described.Meanwhile,related applications,such as high-capacity information coding,highly sensitive detection,and high-performance optic/electric device fabrication,are demonstrated.In addition,the general principle for controlling the droplet impact using heterogeneous wettability substrates is highlighted.Finally,a brief summary of this Account,with challenges and opportunities in this field,is proposed.