Coalescence Behavior of Gold Nanoparticles

The tetraoctylammonium bromide (TOAB)-stabilized gold nanoparticles have been successfully fabricated. After an annealing of the as-synthesized nanoparticles at 300 °C for 30 min, the coalescence behavior of gold nanoparticles has been investigated using high-resolution transmission electron microscopy in detail. Two types of coalescence, one being an ordered combination of two or more particles in appropriate orientations through twinning, and the other being an ordered combination of two small particles with facets through a common lattice plane, have been observed.     

纳米粒子及其在复合材料改性中的应用

介绍了纳米粒子的一些优异特性和表面改性的方法,并详细阐述了纳米粒子充聚合物聚合材料的主要制备方法,研究进展及其良好性能。     

自组装金纳米粒子薄膜SERS研究

采用静电自组装技术制备了金纳米粒子薄膜,研究了薄膜的表面增强拉曼散射(SERS)活性。自组装金纳米粒子薄膜具有明显的SERS效应,其中2双层薄膜的增强效应最强。金纳米粒子相互靠近但又不至于连通的状态具有最强的增强效果。若金纳米粒子通过点、面接触形成连通网络,将导致入射光激发表面等离子体波的机率下低,使增强效果降低。     

Photocatalytic Preparation of Encapsulated Gold Nanoparticles by Jingle-bell-shaped Cadmium Sulfide–silica Nanoparticles

Gold (Au) nanoparticles were deposited inside silica: (SiO₂) shells containing cadmium sulfide (CdS) nanoparticles through photocatalytic reduction of potassium dicyanogold(I) by CdS. Photocatalytic Au deposition occurred only when core-shell nanoparticles having a void space between the core and shell, i.e., a jingle-bell-shaped structure, were used. These core-shell nanoparticles were prepared by size-selective photoetching of SiO₂ -covered CdS nanoparticles. The size of Au nanoparticles could be controlled by adjustment of the void space in SiO₂-covered CdS. Dissolution of CdS by acid treatment from the Au-deposited jingle-bell nanoparticles did not have any effect on the surface-plasmon absorption by Au. These facts indicate that Au nanoparticles of adjustable size can be prepared in an SiO₂ shell that prevents mutual coalescence of Au nanoparticles but allows permeation of molecules and ions.     

12-磷钨酸体系水热法制备金颗粒及其表征

利用Keggin结构的12-磷钨酸作为软模板,采用水热法还原氯金酸制备金颗粒. 考察了AuCl4-离子与12-磷钨酸的摩尔比、反应时间及反应温度对Au颗粒的影响. 用TEM, UV-Vis, FESEM, XPS, XRD等手段对所制金纳米颗粒的形貌、组分、粒径和结构进行了表征. 结果表明,HAuCl4与磷钨酸反应速率较快,可获得尺寸范围较大的球形、三角形、多孪晶和六边形等不同形貌的Au颗粒. 对Au颗粒的形成机理进行了探讨.     

A Kind of Nanofluid Consisting of Surface-Functionalized Nanoparticles

A method of surface functionalization of silica nanoparticles was used to prepare a kind of stable nanofluid. The functionalization was achieved by grafting silanes directly to the surface of silica nanoparticles in silica solutions (both a commercial solution and a self-made silica solution were used). The functionalized nanoparticles were used to make nanofluids, in which well-dispersed nanoparticles can keep good stability. One of the unique characteristics of the nanofluids is that no deposition layer forms on the heated surface after a pool boiling process. The nanofluids have applicable prospect in thermal engineering fields with the phase-change heat transfer.     

纳米金自催化生长及其应用研究

介绍了纳米金基因探针的制备方法,对小尺寸纳米金的自催化性能进行了分析研究,在此基础上,探讨了纳米金自催化机理放大光学信号及其在光学传感器方面的应用价值。     

Size-Controlled Synthesis of Colloidal Gold Nanoparticles at Room Temperature Under the Influence of Glow Discharge

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV–visible absorption spectra (UV–vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV–vis, XPS and EDX results confirmed that Au³⁺ ions in HAuCl₄ solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl₄ solution. Moreover, the as-synthesized Au colloids (d _av = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma.     

纳米金自催化生长及其应用研究

介绍了纳米金基因探针的制备方法,对小尺寸纳米金的自催化性能进行了分析研究,在此基础上,探讨了纳米金自催化机理放大光学信号及其在光学传感器方面的应用价值。     

Binary Mixtures of SH- and CH3-Terminated Self-Assembled Monolayers to Control the Average Spacing Between Aligned Gold Nanoparticles

This paper presents a method to control the average spacing between organometallic chemical vapor deposition (OMCVD) grown gold nanoparticles (Au NPs) in a line. Focused ion beam patterned CH₃-terminated self-assembled monolayers are refilled systematically with different mixtures of SH- and CH₃-terminated silanes. The average spacing between OMCVD Au NPs is demonstrated systematically to decrease by increasing the v/v% ratio of the thiols in the binary silane mixtures with SH- and CH₃-terminated groups.     

Controlled Growth of Colloidal Gold Nanoparticles: Single-Crystalline versus Multiply-twinned Particles

Gold nanocrystals with well-defined shapes are becoming more crucial in application fields as diverse as catalysis, plasmonics, sensing, drug delivery, and therapeutics. To accomplish real applications on a large scale, a tight control over the size and geometry of the nanoparticles is essential. During the last decade, a new view has emerged: the planning of the properties of nanoparticles based on the control of their morphology. This rational design of particles with desired properties requires strategies to control the nucleation and growth processes. This review provides an overview of applications, properties, characterization, and procedures for the growth of nanoparticles with well-defined shapes, emphasizing the differences between the controlled growth of single-crystal and twinned gold nanoparticles.     

Enhancement of the Antitumour Activity for the Synthesised Dodecylcysteine Surfactant using Gold Nanoparticles

In this paper, the surfactant dodecylcysteine hydrochloride was synthesised. The surface parameters of the synthesised surfactant were studied using a surface tension technique. The surface parameters show a good surface activity of the prepared surfactant in aqueous solution. The self-assembling behaviour of the synthesised surfactant comparing with that of cysteine compound on the prepared gold nanoparticles was confirmed using transmission electron microscope (TEM) measurements. The effect of self-assembling of this surfactant on the size of gold nanoparticles was studied using TEM images. The antitumour activity of the prepared surfactant without and with the gold nanoparticles was investigated. The results show that the antitumour activity of the prepared surfactant was enhanced with the presences of the gold nanoparticles.

CdS/Au复合纳米粒子的制备与表征

以Cd(NO3)2.4H2O和Na2S.9H2O为原料,AOT为保护剂,利用反胶束法在正庚烷中合成了CdS/Au复合纳米粒子,加入适量的十二硫醇,利用静置法洗去保护剂AOT,通过加入不同量的无水乙醇改变分散介质的极性,改变CdS/Au复合纳米粒子在分散介质中的"溶解度",从而实现不同尺寸纳米粒子的分离。采用紫外-可见(UV-vis)吸收光谱,透射电子显微镜(TEM)、荧光光谱法等对其进行表征。     

Characterization of surface modified carbon nanoparticles by low temperature plasma treatment

The carbon nanoparticles derived from polypyrrole were treated with oxygen and ammonia radio-frequency plasma. Micro-attenuated total reflection Fourier transform infrared, element analysis, and X-ray photoelectron spectroscopy analyses were performed to confirm the incorporation of polar functional groups onto the carbon nanoparticles. Moreover, the morphology of plasma treated carbon nanoparticles was retained without nanoparticle aggregation. The plasma treated carbon nanoparticles exhibited the enhanced dispersibility in aqueous solution, compared to the pristine carbon nanoparticles.     

氧化石墨烯负载金纳米颗粒及其催化活性研究

在不外加任何还原剂的情况下,利用氯金酸和氧化石墨烯之间的氧化还原反应将金纳米颗粒成功负载到氧化石墨烯上,合成了金纳米颗粒/氧化石墨烯复合材料。利用透射电镜(TEM)和X-射线衍射(XRD)对复合材料进行了结构表征与形态分析,并研究了金纳米颗粒/氧化石墨烯复合材料对Suzuki-Miyaura偶联反应的催化效果。结果表明,通过调节氯金酸与氧化石墨烯的质量比,可以得到不同形状的金纳米颗粒;金纳米颗粒/氧化石墨烯复合材料对Suzuki-Miyaura偶联反应具有很高的催化活性,并且很容易从反应体系中回收。     

Promotion of SH-SY5Y Cell Growth by Gold Nanoparticles Modified with 6-Mercaptopurine and a Neuron-Penetrating Peptide

Much effort has been devoted to the discovery of effective biomaterials for nerve regeneration. Here, we reported a novel application of gold nanoparticles (AuNPs) modified with 6-mercaptopurine (6MP) and a neuron-penetrating peptide (RDP) as a neurophic agent to promote proliferation and neurite growth of human neuroblastoma (SH-SY5Y) cells. When the cells were treated with 6MP-AuNPs-RDP conjugates, they showed higher metabolic activity than the control. Moreover, SH-SY5Y cells were transplanted onto the surface coated with 6MP-AuNPs-RDP to examine the effect of neurite development. It can be concluded that 6MP-AuNPs-RDP attached to the cell surface and then internalized into cells, leading to a significant increase of neurite growth. Even though 6MP-AuNPs-RDP-treated cells were recovered from frozen storage, the cells still maintained constant growth, indicating that the cells have excellent tolerance to 6MP-AuNPs-RDP. The results suggested that the 6MP-AuNPs-RDP had promising potential to be developed as a neurophic nanomaterial for neuronal growth.     

轮状病毒结构蛋白自组装修饰金纳米粒子

通过轮状病毒结构蛋白VP6自组装的方式对金纳米粒子进行了修饰,获得了VP6包覆的金纳米复合材料,改善了金纳米粒子的生物相容性,使其表面带有丰富的化学基团,更易在靶向药物输运、热疗及造影等方面获得新应用。     

乳液聚合法制备PSA纳米微球与PS纳米微球的性能测定

以苯乙烯(St)和甲基丙烯酸(MAA)为原料,采用乳液聚合法共聚制备羧基化聚苯乙烯(PSA)纳米微球。通过改变乳化剂(SDS)的用量、St/MAA的质量配比控制微球性质和大小。利用透射电镜(TEM)、扫描电镜(SEM)、傅里叶红外光谱(FTIR)、差示扫描量热仪(DSC)、热重分析仪(TGA)和Zeta电位仪对PSA纳米微球进行表征。FTIR结果证实MAA成功引入到微球中,TEM和SEM表明当乳化剂用量为单体总质量的10%时,得到大小均匀,直径为45 nm的PSA微球。PSA的玻璃化转变温度和热分解温度随MAA的含量增加而提高。纯PS表面带负电荷,Zeta电位为-17 mV。共聚后的PSA纳米颗粒,其St与MAA物质的量比为10/1. 0,10/1. 5和10/2. 5时,Zeta电位分别为-31. 9、-39. 6和-44 mV。上述结果表明,采用共聚是调节PS微球热性质及表面性质的有效途径。     

用离子液体聚合物制备和稳定金纳米粒子

以1-甲基咪唑和4-乙烯基苄氯制备了聚〔1-甲基-3-(4-乙烯基苯甲基)咪唑氯〕(PMVBIC),并用1HNMR和FTIR进行了结构表征。然后在PMVBIC的水溶液中,用NaBH4还原HAuCl4制备金纳米粒子,通过UV-Vis光谱和TEM分析发现,PMVBIC能有效稳定金纳米粒子,而且PMVBIC和NaBH4的浓度会明显影响金纳米粒子的粒径、形状和分散性,当m(PMVBIC)∶m(HAuCl4)=34.5∶1,n(NaBH4)∶n(HAuCl4)=2∶1时,可以制得粒径约7nm、均匀分散的球形金纳米粒子,室温存放150 d无明显变化。     

Methanobactin-Mediated Synthesis of Gold Nanoparticles Supported over Al2O3 toward an Efficient Catalyst for Glucose Oxidation

Methanobactin (Mb) is a copper-binding peptide that appears to function as an agent for copper sequestration and uptake in methanotrophs. Mb can also bind and reduce Au(III) to Au(0). In this paper, Au/Al₂O₃ catalysts prepared by a novel incipient wetness-Mb-mediated bioreduction method were used for glucose oxidation. The catalysts were characterized, and the analysis revealed that very small gold nanoparticles with a particle size <4 nm were prepared by the incipient wetness-Mb-mediated bioreduction method, even at 1.0% Au loading (w/w). The influence of Au loading, calcination temperature and calcination time on the specific activity of Au/Al₂O₃ catalysts was systematically investigated. Experimental results showed that decomposing the Mb molecules properly by calcinations can enhance the specific activity of Au/Al₂O₃ catalysts, though they acted as reductant and protective agents during the catalyst preparation. Au/Al₂O₃ catalysts synthesized by the method exhibited optimum specific activity under operational synthesis conditions of Au loading of 1.0 wt % and calcined at 450 °C for 2 h. The catalysts were reused eight times, without a significant decrease in specific activity. To our knowledge, this is the first attempt at the preparation of Au/Al₂O₃ catalysts by Mb-mediated in situ synthesis of gold nanoparticles.