银纳米粒子与氧化物纳米异质结构制备及应用

总结了近期银纳米粒子与氧化物纳米异质结构制备及应用研究进展情况,特别是银纳米粒子修饰的氧化钼纳米纤维异质结构、银纳米粒子修饰的钛酸盐纳米纤维异质结构、银纳米粒子@二氧化硅@银纳米粒子三明治异质结构的制备方法与性能表征.介绍了以上三种异质纳米复合结构的催化性能和银纳米粒子修饰的二氧化物纳米纤维异质结构的气体传感性能.     

基于纳米粒子的比色检测及其在化学传感及生物检测的应用

基于纳米粒子的比色检测由于其简单性、多样性而备受关注。在该体系中,目标分析物直接或间接诱发纳米粒子的聚集和分散,从而可通过溶胶的颜色改变实现分析检测。该综述介绍了纳米粒子分散及聚集过程的物理现象,简单讨论了纳米粒子间的作用力,对两种作用机制(粒子间交联和非粒子间交联来调节纳米粒子的分散和聚集)进行了介绍。并对纳米粒子在重金属离子检测、生物检测等方面的应用及方法的分析特性进行了概述,对其未来发展趋势进行了展望。     

纳米粒子在药物传递中的应用

目前,利用纳米粒子传递药物并用于恶性肿瘤组织的靶向识别,进一步提高肿瘤的诊断和治疗水平是一个比较热点的领域,人们期望用制备容易、价格便宜、毒性小的纳米技术来提高肿瘤的治疗效率。然而,由近年的报道来看,所摄入的纳米粒子仅有约0.7%能够到达肿瘤部位,传递效率较低,这无疑加大了治疗应用的难度。本综述中,我们分析了造成纳米粒子靶向药物转运效率较低的原因,包括纳米粒子的转运途径,纳米粒子转运过程中所遇到的屏障,纳米粒子在体内的清除途径等;随后我们介绍了较早应用的聚合物纳米粒子、磁性氧化铁纳米粒子以及目前广泛研究的介孔二氧化硅纳米粒子在药物传递系统构建中的应用情况,还介绍了细胞膜仿生纳米粒子在药物传递系统中的应用;最后,对纳米粒子在药物传递中的研究进行总结和展望。我们希望通过对纳米粒子传递药物的系统研究,进一步促进纳米粒子在药物传递上的研究,加速纳米药物的临床应用。     

纳米粒子的制备及其在打印印刷领域的应用

本文简要介绍了几类纳米粒子的制备及其在打印印刷领域的应用.包括无机纳米粒子复合材料用于绿色打印制版、聚合物乳胶纳米粒子用于喷墨打印制备光子晶体、金属纳米粒子用于印刷电路以及纳米材料用于3D打印,并展望了其发展前景.     

核壳型纳米粒子合成方法及其性能的研究进展

核壳纳米粒子作为复合纳米粒子一个重要的分支,由于其光、磁和催化等方面的优异性能,近年来引起了人们广泛的关注.本文主要介绍了核壳纳米粒子的制备方法及诸多性能,并对核壳纳米粒子的发展进行了展望.     

聚合物纳米粒子的结构和性能对胞吞和细胞功能的影响

随着纳米医学的发展,越来越多的聚合物纳米粒子被用作荧光探针和药物或基因的载体,在生物分析、检测以及药物传输和基因治疗等领域得到应用。细胞的胞吞是细胞将细胞外基质、病毒、微组织或纳米粒子运送到细胞内部的一个重要生理过程。研究细胞对纳米粒子的胞吞,有助于从细胞层次上理解生命现象,掌握细胞内治疗的机理。本文综述了近几年来细胞和聚合物纳米粒子之间相互作用的最新研究结果。首先介绍了用于胞吞研究的常用聚合物纳米粒子体系及其功能化方法,尤其是荧光探针的复合与表面修饰。进而介绍了细胞和聚合物纳米粒子之间相互作用的基本过程,包括聚合物纳米粒子在细胞转运过程中的驱动力、细胞内转运过程、在细胞中的分布及其细胞毒性。对影响聚合物纳米微粒胞吞的因素如纳米粒子浓度、共培养时间、纳米粒子性能（形状、粒径、电荷和PEG修饰）、细胞类型和培养条件等进行了总结。最后重点介绍了用于受体介导细胞胞吞的聚合物纳米粒子体系,指出了目前研究工作中的不足及未来发展方向。     

纳米粒子的控制生长和自组装研究进展

由于在纳米器件上潜在应用,通过化学方法控制的纳米粒子生长,以及纳米粒子自组装的一维、二维和三维点阵受到人们的广泛关注。本文介绍来近年来纳米粒子的控制生长和组装研究的现状。主要探讨了有机稳定剂对纳米粒子形状和尺寸控制的影响。含配位基团和长链烷烃的有机化合物不但可以用控制纳米粒子生长的稳定剂,而且可以用作纳米粒子自组装的模板剂。     

纳米粒子及其材料的特性、应用和制备

本文介绍了纳米粒子的一般概念、特性及本质根源。纳米粒子因其特异的性能在高科技领域得到了日益广泛的应用。文中对纳米材料现有的应用及其前景作了简要的介绍，并综合评述了目前国内外制备纳米粒子的常用方法，综述了引起粒子间团聚的机理和后处理过程中有效地防止团聚的方法。     

软外延生长法构筑纳米粒子超晶格材料

由纳米粒子自下而上自组装而成、高度有序的纳米粒子超晶格材料是近年来兴起的一类新型材料.本文主要概述了软外延生长法构筑纳米粒子超晶格材料的概念及组装策略,结合近几年本课题组的相关研究工作,主要介绍了几种不同的基底材料,以及通过调控基底与纳米粒子之间的相互作用来构建纳米粒子超晶格材料.具体包括以纳米粒子超晶格、有机分子笼晶体以及超分子组装体等作为基底诱导纳米粒子软外延生长.通过软外延生长法可实现对纳米粒子超晶格维度(包括一维、二维以及三维)的有效调控.同时,阐明了纳米粒子与基底材料的弱键相互作用机制,该机制也成为构筑无机纳米粒子/有机分子有序组装体重要的物理化学基础.     

生物法制备各向异性贵金属纳米粒子的研究进展

利用生物法绿色合成各向异性的贵金属纳米粒子(Au,Ag)具有经济环保、制备简单、无毒副作用等优点,成为近年来的研究热点。 本文通过介绍各向异性贵金属纳米粒子的物理化学性质,归纳了生物法,尤其是利用植物源生物质制备各向异性贵金属纳米粒子的研究,并在此基础上进一步阐述了各向异性贵金属纳米粒子的微观生长机理,最后对各向异性贵金属纳米粒子的应用前景做了展望。     

Hybrid polymer/nanoparticle solar cells: preparation, principles and challenges

Hybrid polymer/nanoparticle solar cells have a light harvesting layer composed of semiconducting inorganic nanoparticles and a semiconducting conjugated polymer. They have potential to give high power conversion efficiencies (PCE). However, the PCE values reported for these solar cells are not currently as high as anticipated. This article reviews the main methods currently used for preparing hybrid polymer/nanoparticle solar cells from the colloid perspective. PCE data for the period of 2005-2011 are presented for hybrid polymer/nanoparticle solar cells and compared to those from polymer/fullerene cells. The key reasons for the relatively low PCE values for hybrid polymer/nanoparticle solar cells are uncontrolled aggregation and residual insulating ligands at the nanoparticle surface. Two hybrid polymer/nanoparticle systems studied at Manchester are considered in which the onset of aggregation and its affect on composite film morphology were studied from the colloidal perspective. It is concluded that step-change approaches are required to increase the PCEs of hybrid polymer/nanoparticle solar cells and move them toward the 10% value required for widespread commercialisation. A range of nanoparticles that have potential for application in possible longer term terawatt solar energy production are discussed.     

Transparent polymeric hybrid film of ZnO nanoparticle quantum dots and PMMA with high luminescence and tunable emission color

ZnO nanoparticle quantum dots (QDs)/poly(methyl methacrylate) (PMMA) composites are synthesized by conventional radical polymerization in the presence of 3-(trimethoxysilyl)propylmethacrylate (TPM)-modified ZnO nanoparticle QDs. Although unmodified ZnO nanoparticle QDs were precipitated in tetrahydrofuran (THF) and show only weak emissions under UV irradiation, ZnO nanoparticle QDs/PMMA composite is well dispersed in THF and shows high emissions. TPM acts as the stabilizer and promotes the compatibility between the ZnO nanoparticle QDs and the PMMA matrix. After evaporation of THF from the ZnO nanoparticle QDs/PMMA composite solution, transparent polymeric hybrid films of ZnO nanoparticle QDs and PMMA are obtained. These polymeric hybrid films are characterized by photoluminescence (PL) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and thermogravimetric analysis. The hybrid film exhibited a high quantum yield and PL emission under ultraviolet excitation. PL emission has been successfully tuned from blue to yellow.     

表面修饰MnS纳米微粒的结构表征

采用表面修饰的方法 ,以双十八烷基二硫代磷酸盐 (PyDDP)为表面修饰剂 ,制备了双十八烷氧基二硫代磷酸 (DDP)表面修饰的MnS纳米微粒。采用TEM ,DSC ,XRD和FTIR对表面修饰MnS纳米微粒进行结构分析。结果表明 :表面修饰MnS纳米微粒是由DDP表面修饰层和MnS纳米核心所构成 ,微粒尺寸在 5～ 10nm之间 ,无机MnS纳米晶核具有 γ MnS的晶型结构。DDP表面修饰MnS纳米微粒在氯仿、苯和甲苯等有机溶剂中都具有良好的分散性。     

Preparation of high-quality organic semiconductor nanoparticle films by solvent-evaporation-induced self-assembly

Organic semiconductor nanoparticles are expected to be used in organic optical and electronic devices due to their unique optical and electrical properties. However, no method has been reported for the preparation of high-quality organic nanoparticle films without remaining additives and being capable of dealing with binary nanoparticle blends. We developed a simple approach to fabricate high-quality organic semiconductor nanoparticle films from their aqueous solutions by solvent-evaporation-induced self-assembly. Only volatile solvents are employed in the nanoparticle solutions, so the self-assembled nanoparticle films are free of additives. Moreover, this method is also suitable for fabricating thin films containing binary nanoparticles. Therefore, it paves the way for potential applications of organic semiconductor nanoparticles in nanoscale optical and electronic devices.     

Size ratio effects on interparticle interactions and phase behavior of microsphere-nanoparticle mixtures

We investigate the interparticle interactions and phase behavior of microsphere-nanoparticle mixtures of high charge asymmetry and varying size ratio. In the absence of nanoparticles, negligibly charged microspheres flocculate as a result of van der Waals interactions. Upon addition of a lower critical nanoparticle volume fraction, the microspheres are stabilized by the formation of nanoparticle halos around each microsphere. , A weak attraction between the two species leads to a pronounced enhancement of the effective nanoparticle concentration near the microsphere surface relative to the bulk solution. Above an upper critical nanoparticle volume fraction, the microspheres undergo reentrant gelation. Binary mixtures, in which the effective nanoparticle size is reduced at a fixed microsphere diameter, exhibit a narrow window of stability that ultimately disappears with increasing ionic strength. By contrast, binary mixtures of varying microsphere diameter are stabilized at similar nanoparticle volume fractions and exhibit a broader window of stability with decreasing size ratio. This unexpected observation may arise from the reduced attraction between smaller microspheres because negligible differences in nanoparticle halo formation are observed in these mixtures.     

A discrete interaction model/quantum mechanical method to describe the interaction of metal nanoparticles and molecular absorption

A frequency-dependent quantum mechanics/molecular mechanics method for the calculation of response properties of molecules adsorbed on metal nanoparticles is presented. This discrete interaction model/quantum mechanics (DIM/QM) method represents the nanoparticle atomistically, thus accounting for the local environment of the nanoparticle surface on the optical properties of the adsorbed molecule. Using the DIM/QM method, we investigate the coupling between the absorption of a silver nanoparticle and of a substituted naphthoquinone. This system is chosen since it shows strong coupling due to a molecular absorption peak that overlaps with the plasmon excitation in the metal nanoparticle. We show that there is a strong dependence not only on the distance of the molecule from the metal nanoparticle but also on its orientation relative to the nanoparticle. We find that when the transition dipole moment of an excitation is oriented towards the nanoparticle there is a significant increase in the molecular absorption as a result of coupling to the metal nanoparticle. In contrast, we find that the molecular absorption is decreased when the transition dipole moment is oriented parallel to the metal nanoparticle. The coupling between the molecule and the metal nanoparticle is found to be surprisingly long range and important on a length scale comparable to the size of the metal nanoparticle. A simple analytical model that describes the molecule and the metal nanoparticle as two interacting point objects is found to be in excellent agreement with the full DIM/QM calculations over the entire range studied. The results presented here are important for understanding plasmon-exciton hybridization, plasmon enhanced photochemistry, and single-molecule surface-enhanced Raman scattering.     

Preparation of palladium nanoparticles–titanium electrodes as a new anode for direct methanol fuel cells

Pd nanoparticle/Ti electrodes are prepared by electroless plating of palladium on titanium plates. The morphology and surface analysis of Pd nanoparticle/Ti electrodes are investigated using scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The results indicate that palladium nanoparticles are homogeneously deposited on the surface of titanium plates. The electro-catalytic activity of Pd nanoparticle/Ti electrodes in the methanol electro-oxidation is studied by cyclic voltammetry and chronoamperometry methods. The results show that the electro-catalytic oxidation of methanol on the Pd nanoparticle/Ti electrode improved compare to pure palladium electrode and confirmed the better electro-catalytic activity and stability of these new electrodes.     

Experimental investigation of nanoparticle dispersion by beads milling with centrifugal bead separation

A new type of beads mill for dispersing nanoparticles into liquids has been developed. The bead mill utilizes centrifugation to separate beads from nanoparticle suspensions and allows for the use of small sized beads (i.e. 15-30 microm in diameter). The performance of the beads mill in dispersing a suspension of titanium dioxide nanoparticle with 15 nm primary particles was evaluated experimentally. Dynamic light scattering was used to measure titania particle size distributions over time during the milling process, and bead sizes in the 15-100 microm range were used. It was found that larger beads (50-100 microm) were not capable of fully dispersing nanoparticles, and particles reagglomerated after long milling times. Smaller beads (15-30 microm) were capable of dispersing nanoparticles, and a sharp peak around 15 nm in the titania size distribution was visible when smaller beads were used. Because nanoparticle collisions with smaller beads have lower impact energy, it was found by X-ray diffraction and transmission electron microscopy that changes in nanoparticle crystallinity and morphology are minimized when smaller beads are used. Furthermore, inductively-coupled plasma spectroscopy was used to determine the level of bead contamination in the nanoparticle suspension during milling, and it was found that smaller beads are less likely to fragment and contaminate nanoparticle suspensions. The new type of beads mill is capable of effectively dispersing nanoparticle suspensions and will be extremely useful in future nanoparticle research.     

Functionalized surface as template for in situ generation of two-dimensional metal nanoparticle assembly

Two-dimensional gold nanoparticle assemblies with an average nanoparticle size of 6 nm are generated on silicon and indium tin oxide (ITO)-coated glass surfaces, functionalized with polyethylenimine (PEI) silane monolayer. Contact angle measurements show increased hydrophilic character of the surface due to nanoparticle formation. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) are used to monitor the chemical and structural development of these nanostructures, while UV–vis spectroscopy is used to follow the formation of the nanoparticle assemblies. This paper elucidates a simple route to in situ synthesis of surface immobilized gold nanoparticles under ambient conditions and also extends to the synthesis of other surface bound nanoparticles, like silver and platinum. Gold nanoparticle assemblies generated in this study are also catalytically active towards methanol oxidation reaction (MOR), which is relevant for direct methanol fuel cells (DMFCs).     

Switchable water absorption of paper via liquid flame spray nanoparticle coating

Surface wetting/anti-wetting and liquid absorption are relevant properties of many porous solids including paper and other cellulose-based materials. Here we demonstrate how surface wetting by water and water absorption of commercially available kraft paper can be altered by thin nanoparticle coatings fabricated by liquid flame spray in facile and continuous one-step process. Surface wettability and absorption properties of paper increased with silica and decreased with titania (TiO₂) nanoparticle coatings. Moreover, the water-repellent (superhydrophobic) TiO₂ nanoparticle coated paper could be switched to superhydrophilic and water absorbing by ultraviolet illumination. The experiments revealed that although surface wetting and liquid absorption of nanoparticle coated paper are strongly related to each other, they are two distinct phenomena which do not necessarily correlate. We propose wetting regimes on the nanoparticle coated paper samples on the basis of the experimental observations.