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1.
Active particles can autonomously propel and have the tendency to organize into high-order ensembles and phases that evolve and reconfigure. They have emerged as a focused subject in contemporary colloid science, holding great promise in advancing fields, such as cargo delivery, sensing, micromachinery and microrobotics, and materials science. Realization of the full potentials of active particles requires delicate control of their dynamics in propulsion and assembly, which is challenging due to the out-of-equilibrium nature of such systems. Recently, systematically engineered colloidal shapes have been exploited as an effective means to tune and even program the dynamic behaviors of active particles. Various anisotropic particles, with controlled geometries and possessing either homogeneous or heterogeneous composition, have been fabricated, regulating how particles actively propel, interact, and assemble under several chemical and physical stimuli. In this paper, we provide an overview of these progresses. We also briefly discuss our view on the future directions and challenges.  相似文献   
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While extensive theoretical work has been devoted to analyzing scattering behavior for nonspherical particles, few experimental studies of the light‐scattering properties of such particles are available, largely because of the difficulty of synthesizing such particles with uniform geometries. Here we report the synthesis of highly uniform, volume‐equivalent rod‐shaped colloidal particles prepared from their commercial spherical counterparts, on which we performed light scattering experiments as a function of scattering angle for micro rods with varying aspect ratio and volume. These results were compared to values calculated using the T‐Matrix method. Good agreement with theoretical predictions was found for the experimentally measured scattering cross sections and the angular dependence of the scattering intensity. An increase in the forward scattering intensity is observed and predicted for particles with larger aspect ratios relative to their volume equivalent spheres, with only minor differences observed at both mid‐range and backscattering angles. Furthermore, the light scattering results for the rod‐shaped particles did not show the scattering fringes seen in scattering by the spheres, indicating that as three‐dimensional symmetry is broken, the associated Lorenz–Mie resonances are strongly attenuated. This observation also was predicted by theory. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1889–1895  相似文献   
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Two-dimensional (2D) Au(I)-thiolate assemblies are a special type of material that can balance high structural stability and rich surface functionality, which shows promising prospects in both fundamental research and applications. Co-assembly of multiple ligands is a facile way to further enrich the surface properties and functions, and expand their application potentials. In this work, taking 3-mercaptopropionic acid (MPA), cysteine (Cys) and 1-thioglycerol (TGO) as example ligands, we studied in detail the possibility to co-assemble them into one nanosheet. Although the three ligands have significantly different controllability and pathways when self-assembling individually with Au(I), they can still be effectively co-assembled by reacting with HAuCl4 together to obtain three-ligand nanosheets with good colloidal stability. The key points for successful co-assembly are also revealed by comparing single- and three-ligand self-assembly processes, laying a solid foundation for co-assembly of even more ligands. The easy but powerful strategy for 2D materials with closely-packed and multiple tunable surface functional groups addresses the surface engineering problem for 2D materials and paves the way for their wider applications in sensing and biomaterials.  相似文献   
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Chemical analyses in the field using surface-enhanced Raman scattering (SERS) protocols are expected to be part of several analytical procedures applied to water quality monitoring. To date, these endeavors have been supported by developments in SERS substrate nanofabrication, instrumentation portability, and the internet of things. Here, we report distinct chemical strategies for preparing magneto-plasmonic (Fe3O4 : Au) colloids, which are relevant in the context of trace-level detection of water contaminants due to their inherent multifunctionality. The main objective of this research is to investigate the role of poly(amidoamine) dendrimers (PAMAMs) in the preparation of SERS substrates integrating both functionalities into single nanostructures. Three chemical routes were investigated to design magneto-plasmonic nanostructures that translate into different ways for assessing SERS detection by using distinct interfaces. Hence, a series of magneto-plasmonic colloids have been characterized and then assessed for their SERS activity by using a model pesticide (thiram) dissolved in aqueous samples.  相似文献   
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王文涛  赵高崇  杨柳  周意诚  丁黎明 《化学学报》2022,80(12):1576-1582
结合Fe3O4@SiO2 (M)超顺磁胶体粒子动态连续的磁致变色和碲化镉量子点(CdTe QDs)瞬时发射的光致发光特性, 采用聚二甲基硅氧烷(PDMS)弹性体封装含有M胶体粒子和CdTe QDs的乙二醇(EG)微液滴, 制得了具有多重变色功能的M/QDs/EG/PDMS复合薄膜. 利用光学显微镜、光纤光谱仪、荧光光谱仪、数码相机、拉力试验机对复合薄膜的内部结构、光学性质及力学性能进行表征. 结果表明, 在外界磁场的诱导下, 复合薄膜瞬时呈现明亮的结构色, 且随着磁场强度的降低, 复合薄膜的衍射波长发生连续红移, 移动范围可达145 nm. 此外, 在紫外光的激发下, 复合薄膜可呈现特定波长的荧光发射, 具备良好的光致发光特性. 同时, 复合薄膜断裂伸长率可达132%, 表现出良好的弹性, 这为其附着在不同材料表面实现防伪应用提供了基础. 进一步地, 通过图案化设计, 可制得响应变色迅速、图案隐现可逆、颜色变化多样的防伪薄膜, 这有利于其在信息加密和高级别防伪领域中的应用.  相似文献   
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Rapid and selective removal of micropollutants from water is important for the reuse of water resources. Despite hollow frameworks with specific functionalized porous walls for the selective adsorption based on a series of interactions, tailoring a stable shape of nanometer- and micrometer-sized architectures for the removal of specific pollutants remains a challenge. Here, exactly controlled sheets, tubes, and spherical frameworks were presented from the crosslinking of supramolecular colloids in polar solvents. The frameworks strongly depended on the architecture of original supramolecular colloids. As the entropy of colloids increased, the initial laminar framework rolled up into hollow tubules, and then further curled into hollow spheres. These shape-persistent frameworks showed unprecedented selectivity as well as specific recognition for the shape of pollutants, thus contributing to efficient pollutant separation.  相似文献   
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We discuss the peculiarities of the Seebeck effect in stabilized electrolytes containing the colloidal particles. Its unusual feature is the two stage character, with the linear increase of differential thermopower as the function of colloidal particles concentration n during the first stage (“initial state”) and dramatic drop of it at small n during the second one (“steady state”). We show that the properties of the initial state are governed by the thermo-diffusion flows of the mobile ions of the stabilizing electrolyte medium itself and how the colloidal particles participate in the formation of the electric field in the bulk of the suspension. In its turn, we attribute the specifics of the steady state thermoelectric effect the massive colloidal particles undergoing slow thermal diffusion and the break down of their electro-neutrality in the vicinity of electrodes.  相似文献   
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Since the outbreak of the COVID-19 pandemic, most countries have recommended their citizens to adopt social distance, hand hygiene, and face mask wearing. However, wearing face masks has not been well adopted by many citizens. While the reasons are complex, there is a general perception that the evidence to support face mask wearing is lacking, especially for the general public in a community setting. Face mask wearing can block or filter airborne virus-carrying particles through the working of colloid and interface science. This paper assesses current knowledge behind the design and functioning of face masks by reviewing the selection of materials, mask specifications, relevant laboratory tests, and respiratory virus transmission trials, with an overview of future development of reusable masks for the general public. This review highlights the effectiveness of face mask wearing in the prevention of COVID-19 infection.  相似文献   
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