Name: in situ synthesis of gold nanoparticles without aggregation in the interlayer space of layered titanate transparent films
Uploaded: 2017-01-17T14:00:00.000+00:00
Duration: 7 min 8 s
Description: Watch this Scientific Journal Video about In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films at JoVE.com

This work was partly supported by Nippon Sheet Glass Foundation for Materials Science and Engineering and JSPS KAKENHI (Grant-in-Aid for Challenging Exploratory Research, #50362281).

Cuidado: Tenha cuidado ao trabalhar com produtos químicos e soluções. Siga as práticas de segurança apropriadas e usar luvas, óculos e um casaco de laboratório em todos os momentos. Esteja ciente de que os nanomateriais podem ter riscos adicionais, em comparação com o seu homólogo granel. 1. Preparação de Regentes <ol><li> Preparar a solução de metilviologênio aquosa dissolvendo 0,0012 g de dicloreto de 1,1&#39;-dimetil-4,4&#39;-bipiridínio (metilviologênio; MV 2+) em 20 ml de água para dar 0,2 mM MV 2+. </li><li> Prepara-se o ouro (III), solução aquosa de cloreto dissolvendo 0,1050 g de ouro (III) tri-hidrato de tetracloreto de (HAuCl 4 • 3H 2 O) em 10 ml de água para dar 25 HAuCl 4 mM. </li><li> Preparar a solução de boro-hidreto de sódio aquosa por dissolução de 0,03844 g de tetra-hidroborato de sódio (NaBH4) em 10 ml de água para dar 100 mM de NaBH 4. </li><li> Preparar a solução aquosa de 2 ammoniumethanethiol por dissolving 0,2985 g de sal de cloreto de 2-ammoniumethanethiol (2-AET +) em 25 ml de água para dar 100 mM de 2-AET +. </li></ol> 2. Síntese do TNS coloidais Suspensões NOTA: nanofolhas Titânia (TNS; Ti 0,91 O 2) foram preparados de acordo com o procedimento bem estabelecido relatado anteriormente 22,23,30. <ol><li> Prepara-se o material de partida de camadas de césio titanato Cs 0,7 Ti 1.825 O 4 por calcinação de uma mistura estequiométrica de Cs 2 CO 3 (0,4040 g) e de TiO 2 (ST-01; 0,5000 g) a 800 ° C durante 20 h 22. Repita isso duas vezes. </li><li> Prepara-se o titanato em camadas protonada (H 0.7 Ti 1.825 O 4? H 2 O) por tratamento de repetidamente 0,8142 g de titanato de césio com um HCl (100 mM, 81.42 ml) solução aquosa, utilizando o agitador (300 Hz), durante 12 h. </li><li> Prepare o titanato de camadas esfoliada (TNS) suspensões coloidais poragitar o pó protonada titanato (0,0998 g) vigorosa (500 rpm) com 25 ml de um hidróxido de tetrabutilamónio 17 mM (TBA + OH -) solução aquosa para cerca de 2 semanas à temperatura ambiente sob condições de escuridão. A suspensão resultante contém opalescente esfoliada nanofolhas titânia (TNS; 1,4 g / L, pH = 11 ~ 12). </li></ol> 3. Síntese do TNS Films 21 <ol><li> Preparação de TNS lançou filmes (c-TNS) <ol><li> Substratos de vidro pré-limpo (~ 20 x 20 mm 2) por meio de tratamentos de ultra-sons, usando um líquido de limpeza de ultra-sons (27 kHz) em hidróxido de sódio aquoso 1 M (NaOH) durante 30 min. </li><li> Lavar os substratos com 5-10 ml de água ultrapura (&lt;0,056 microsiemens cm -1). </li><li> Mergulhar um substrato de vidro em um ácido clorídrico aquoso a 0,1 M (HCl) durante 3 minutos e lavar com 5-10 ml de água ultrapura. </li><li> Limpar os substratos por meio de tratamentos de ultra-sons (27 kHz) em água pura para 1 hr, eem seguida, enxaguar com água pura. Seque com secador de cabelo por 2-3 min (até secar). </li><li> Fundido a suspensão coloidal de TNS sobre o substrato de vidro em alíquotas de 300 ul. </li><li> Seco a 60 ° C durante 2 horas usando um forno seco para dar o filme C-TNS. </li></ol></li><li> Preparação de sinterizado TNS Film (s-TNS) <ol><li> Para obter uma fixação térmica dos componentes TNS sobre o substrato de vidro (S-TNS filme), sinterização a obtida filme C-TNS ao ar a 500 ° C durante 3 horas (aquecimento entre 25 e 500 ° C a uma velocidade de 6,8 ° C / min) utilizando o forno. </li><li> Repita o processo de sinterização duas vezes. </li></ol></li><li> Preparação de Películas <ol><li> Quando os filmes s-TNS são imersos em solução, posicione o filme s-TNS depositados para que ele enfrenta o topo para todos os procedimentos experimentais. </li><li> Realizar todos os experimentos em condições escuras cobrindo a configuração com papel alumínio para evitar a fotorreação da TNS. </li></ol></li><li> Préparação de Metil viologen (MV 2+) intercalados TNS Films (TNS / MV 2+) <ol><li> Imergir uma película S-TNS, em uma solução aquosa de sal de dicloreto de MV 2+ (0,2 mM, 3 ml) numa placa de Petri durante 7 h à temperatura ambiente (TA), no escuro. </li><li> Lavar as amostras obtidas com água ultrapura (5-10 ml) e seco ao ar a 60 ° C utilizando um forno no escuro durante ~ 1 h. </li></ol></li><li> Preparação de Au (III) intercalados TNS Films (TNS / Au (III)) <ol><li> Imergir uma película TNS / MV 2+ numa solução aquosa de HAuCl 4 (25 mM, 3 ml) numa placa de Petri, durante 3 h à temperatura ambiente sob condições de escuridão. </li><li> Lavar as amostras obtidas com água ultrapura (5-10 ml) e seco ao ar a 60 ° C utilizando um forno no escuro durante ~ 1 h. </li></ol></li><li> Síntese de AUNP dentro do espaço Interlayer da TNS Films (TNS / AUNP) <ol><li> Imergir uma película TNS / Au (III) em uma solução aquosa de NaBH4 </sub&gt; (0,1 M, 5 mL) em uma placa de Petri durante 0,5 horas à temperatura ambiente sob condições de escuridão. </li><li> Secam-se as películas obtidas em ar a 60 ° C utilizando um forno no escuro durante ~ 1 h. </li></ol></li><li> Preparação de 2-AET + intercalados TNS Films (TNS / 2-AET +) <ol><li> Imergir uma película S-TNS, em uma solução aquosa de 2-AET + Cl - (0,1 M, 3 mL) em uma placa de Petri durante 24 h à TA. </li><li> Enxaguar obtidos filmes com água ultrapura (5-10 ml) e seco ao ar a 60 ° C utilizando um forno no escuro durante ~ 1 h. </li></ol></li><li> Au (III) e 2-AET + Co-intercalados TNS Films (TNS / 2-AET + / Au (III)). <ol><li> Imergir uma película TNS / 2-AET + numa solução aquosa de HAuCl 4 (25 mM, 3 ml) durante 3 h à TA. </li><li> Lavar os filmes obtidos com água ultrapura (5-10 ml) e seco ao ar a 60 ° C utilizando um forno no escuro durante ~ 1 h. </li></ol></li><li> Síntese de AUNP within o Espaço Interlayer da TNS / 2-AET + Films (TNS / 2-AET + / AUNP). <ol><li> Imergir a / 2-AET filme TNS + / Au (III) em uma solução aquosa de NaBH 4 (0,1 M, 5 mL) em uma placa de Petri durante 0,5 horas à temperatura ambiente sob condições de escuridão. </li><li> Lavar os filmes obtidos com água ultrapura (5-10 ml) e seco ao ar a 60 ° C utilizando forno no escuro durante ~ 1 h. </li></ol></li><li> caracterizações <ol><li> Realizar de difracção de raios-X (DRX) 21 utilizando um difractómetro de raios-X de mesa com monochromatized α radiação Cu-K (λ = 0,15405 nm), operado a 30 kV e 15 mA. </li><li> Tome energia dispersiva espectrometria de raios-X (EDS) espectros 21. </li><li> Empregar um fotodetector multicanal ou steady-state ultravioleta-visível (UV-Vis) espectrofotômetro de absorção para gravar espectros de absorção UV-Vis para as amostras preparadas utilizando o modo de transmissão 21. </li></ol></li></ol>

We have nothing to disclose.

Este manuscrito proporciona um protocolo detalhado para a síntese in situ de nanoparticulas de ouro (AuNPs) dentro do espaço interlamelar de filmes TNS. Este é o primeiro relatório do in situ síntese de AuNPs dentro do espaço intercalar da TNS. Além disso, descobrimos que o 2-AET + funciona como um reagente de protecção eficaz para AuNPs dentro do intercalar da TNS. Estes métodos hybridized AuNPs e TNS filmes transparentes. Filmes TNS com boa transparência óptica 21 fo...

Vários nanopartículas de metais nobres (MNPS) exibem cores características ou tons devido à sua ressonância de plasma de superfície localizada propriedades (LECC); Assim, MNPs pode ser usado em várias aplicações ópticas e / ou fotoquímicos 1-4. Recentemente, combinações de fotocatalisadores semicondutores de óxido metálico (MOS), tal como óxido de titânio (TiO 2) e MNPs, foram cuidadosamente investigados como novos tipos de fotocatalisadores 5-14. No entanto, em muitos casos, existem quantidades muito pequenas de MNPs na superfície do MOS, porque a maioria das partículas têm áreas de superfície MOS relativamente baixas. Por outro lado, os semicondutores de óxido de metal em camadas (LMOSs) exibem propriedades foto catalíticas e ter uma grande área superficial, tipicamente, várias centenas de metros quadrados por unidade de g de um LMOS 15-17. Além disso, vários LMOSs têm propriedades de intercalação (por exemplo, várias espécies químicas podem ser acomodados dentro dos seus espaços intercamada expansíveis e grandes) 15-20. Assim, com uma combinação de MNPS e LMOSs, espera-se que quantidades relativamente grandes de MNPs são hibridados com os fotocatalisadores semicondutores. Nós relatamos o primeiro na síntese in situ de nanopartículas de cobre (CuNPs) 21 dentro do espaço intercalar de OVMs (titânia nanosheet; TNS 16-30) filmes transparentes através de passos muito simples. No entanto, os detalhes dos procedimentos de síntese e a caracterização dos outros híbridos MnPs e TNS nobres ainda não foram relatados. Além disso, os CuNPs dentro das camadas TNS foram facilmente oxidados e descorou-se sob as condições ambientes 21. Como tal, nós nos concentramos em nanopartículas de ouro (AuNPs), porque AuNPs são amplamente utilizados para vários óptica, fotoquímica e aplicações catalíticas, e espera-se que eles vão ser relativamente estável contra a oxidação 3-5,7,8,10-14 , 28,31,32. Aqui, nós relatamos a síntese de AuNPs dentro do espaço intercalar da TNS e mostrar that 2-ammoniumethanethiol (2-AET +; Figura 1 inserção) funciona eficazmente como um reagente de protecção para AuNPs dentro do intercalar da TNS.

<table><tbody><tr><td>Methyl viologen dichloride</td><td>Aldrich Chemical&amp;nbsp; Co., Inc.</td><td>1910-42-5</td><td></td></tr><tr><td>Tetrabutylammonium hydroxide</td><td>TCI</td><td>T1685</td><td></td></tr><tr><td>cesium carbonate</td><td>Kanto Chemical Co., Inc.</td><td>07184-33</td><td></td></tr><tr><td>anatase titanium dixoide</td><td>Ishihara Sangyo Ltd.</td><td>ST-01</td><td></td></tr><tr><td>hydrochloric acid</td><td>Junsei Chemical Co., Ltd.</td><td>20010-0350</td><td></td></tr><tr><td>sodium hydroxide</td><td>Junsei Chemical Co., Ltd.</td><td>195-13775</td><td></td></tr><tr><td>Tetrachloroauric(III) acid trihydrate</td><td>Kanto Chemical Co., Inc.</td><td>17044-60</td><td></td></tr><tr><td>sodium tetrahydroborate</td><td>Junsei Chemical Co., Ltd.</td><td>39245-1210</td><td></td></tr><tr><td>2-ammoniumethanethiol hydrochloride</td><td>TCI</td><td>A0296</td><td></td></tr><tr><td>Ultrapure water (0.056 &amp;micro;S/cm)</td><td></td><td></td><td>Milli-Q water purification system (Direct-Q&lt;sup&gt;&amp;reg;&lt;/sup&gt; 3UV, Millipore)</td></tr><tr><td>Microscope slide (Thickness: 1.0&amp;#8211;1.2 mm)</td><td>Matsunami glass Co., Ltd.</td><td></td><td></td></tr></tbody></table>

in situ synthesis of gold nanoparticles without aggregation in the interlayer space of layered titanate transparent films

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs within the interlayer space of semiconducting layered titania nanosheet (TNS) films was investigated here. Two types of intermediate films (i.e., TNS films containing methyl viologen (TNS/MV2+) and 2-ammoniumethanethiol (TNS/2-AET+)) were prepared. The two intermediate films were soaked in an aqueous tetrachloroauric(III) acid (HAuCl4) solution, whereby considerable amounts of Au(III) species were accommodated within the interlayer spaces of the TNS films. The two types of obtained films were then soaked in an aqueous sodium tetrahydroborate (NaBH4) solution, whereupon the color of the films immediately changed from colorless to purple, suggesting the formation of AuNPs within the TNS interlayer. When only TNS/MV2+ was used as the intermediate film, the color of the film gradually changed from metallic purple to dusty purple within 30 min, suggesting that aggregation of AuNPs had occurred. In contrast, this color change was suppressed by using the TNS/2-AET+ intermediate film, and the AuNPs were stabilized for over 4 months, as evidenced by the characteristic extinction (absorption and scattering) band from the AuNPs.

Dois tipos de filmes precursoras foram utilizados neste estudo (ou seja, com e sem o reagente de protecção (2-AET +) no interior da camada intermédia de TNS). Na ausência de 2-AET +, 1,1&#39;-dimetil-4,4&#39;-bipiridínio dicloreto de (metilviologênio; MV 2+) foi usado como um expansor do espaço interlamelar, porque MV 2+ molecular contendo LMOSs tenham sido freqüentemente usados como intermediários na método de troca convidad...

Watch this Scientific Journal Video about In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films at JoVE.com

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Aqui, apresentamos um protocolo para a in situ síntese de nanopartículas de ouro (AuNPs) dentro do espaço interlamelar de filmes de titanato de camadas sem a agregação de AuNPs. Nenhuma mudança foi observada espectral mesmo após 4 meses. O material sintetizado tem esperado aplicações em catálise, foto-catálise, e para o desenvolvimento de dispositivos plasmonic rentáveis.

In situ Síntese de Nanopartículas de Ouro sem agregação no espaço Interlayer de Layered titanato filmes transparentes

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs ...

in-situ-synthesis-gold-nanoparticles-without-aggregation-interlayer

Research

JoVE Journal

Engineering

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

8.1K visualizações.  Niigata University.  Aqui, apresentamos um protocolo para a in situ síntese de nanopartículas de ouro (AuNPs) dentro do espaço interlamelar de filmes de titanato de camadas sem a agregação de AuNPs. Nenhuma mudança foi observada espectral mesmo após 4 meses. O material sintetizado tem esperado aplicações em catálise, foto-catálise, e para o desenvolvimento de dispositivos plasmonic rentáveis. 

Vídeo: In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

Dirigido modelo de síntese de nanotubos de Ouro plasmônicos com Absorbância IR Tunable

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

Química

A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and scalable technique efficiently functionalizes metallic nanoparticles with thiol-ligands in a miscible water/organic solvent mixture allowing for rapid grafting of thiol groups onto the gold nanoparticle surface. The hydrophobic ligands on the nanoparticles then quickly phase separate the nanoparticles from the aqueous based suspension and confine them to the air-fluid interface. This drives the ligand-capped nanoparticles to form monolayer domains at the air-fluid interface.&#160; The use of water-miscible organic solvents is important as it enables the transport of the nanoparticles from the interface onto template-free substrates.&#160; The flow is mediated by a surface tension gradient3,4 and creates macroscopic, high-density, monolayer nanoparticle-ligand films.&#160; This self-assembly technique may be generalized to include the use of particles of different compositions, size, and shape and may lead to an efficient assembly method to produce low-cost, macroscopic, high-density, monolayer nanoparticle films for wide-spread applications.

A simple, robust and scalable technique to functionalize and self-assemble macroscopic nanoparticle-ligand monolayer films onto template-free substrates is described in this protocol.

Uma técnica para funcionalizar e auto-montar macroscópicas Nanopartículas-ligante monocamada Films em substratos sem Modelo

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and ...

Synthesis, Assembly, and Characterization of Monolayer Protected Gold Nanoparticle Films for Protein Monolayer Electrochemistry

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM).1-3 In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction4 and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton (1H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials.5-8

Alkanethiolate stabilized gold colloids known as monolayer protected clusters (MPCs) are synthesized, characterized, and assembled into thin films as an adsorption interface for protein monolayer electrochemistry of simple redox protein like Pseudomonas aeruginosa azurin (AZ) and cytochrome c (cyt c).

Síntese, Assembléia e Caracterização de monocamada Protected Films nanopartículas de ouro para Eletroquímica monocamada Protein

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently ...

Bioengenharia

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

Templates atomicamente definidos para crescimento epitaxial do Complexo Óxido Filmes Finos

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties of the materials were investigated. We used a one pot sol-gel approach to intercalate gold nano particles in the walls of mesoporous silica. To start with the synthesis, P123 was used as template to form micelles. Then TESPTS was used as a surface modification agent to intercalate gold nano particles. Following this process, TEOS was added in as a silica source which underwent a polymerization process in acid environment. After hydrothermal processing and calcination, the final product was acquired. Several techniques were utilized to characterize the porosity, morphology and structure of the gold intercalated mesoporous silica. The results showed a stable structure of mesoporous silica after gold intercalation. Through the oxidation of benzyl alcohol as a benchmark reaction, the GMS materials showed high selectivity and recyclability.

Here, we present a protocol with a sol-gel process to synthesize gold intercalated in the walls of mesoporous materials (GMS), which is confirmed to possess a mesoporous matrix with gold intercalated in the walls imparting great stability and recyclability.

Síntese e desempenho catalítico de ouro intercalados nas paredes de mesoporosos Silica

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

Síntese e Reacção Química de nanosize monossódico Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

Um método simples para o tamanho Síntese controlada de estáveis ​​Oligoméricas Clusters de nanopartículas em condições ambientais

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

Fabricação de matrizes de periódicos Nanocup ouro usando litografia coloidal

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Engenharia

Growth of Gold Dendritic Nanoforests on Titanium Nitride-coated Silicon Substrates

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a fluoride-assisted galvanic replacement reaction (FAGRR) is employed for the rapid and easy deposition of gold dendritic nanoforests (Au DNFs) on the TiN/Si substrates. Scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy patterns of TiN/Si and Au DNFs/TiN/Si samples validate that the synthesis process is accurately controlled. Under the reaction conditions in this study, the thickness of the Au DNFs increases linearly to 5.10 &#177; 0.20 &#181;m within 15 min of the reaction. Therefore, the employed synthesis procedure is a simple and rapid approach for preparing Au DNFs/TiN/Si composites.

This study presents a feasible procedure for synthesizing gold dendritic nanoforests on titanium nitride/silicon substrates. The thickness of gold dendritic nanoforests increases linearly within 15 min of a synthesis reaction.

Crescimento de nanoformas dendríticos de ouro em substratos de silício revestidos de nitreto de titânio

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.

In situ Síntese de Nanopartículas de Ouro sem agregação no espaço Interlayer de Layered titanato filmes transparentes

Resumo

Explore mais vídeos

Capítulos neste vídeo

Dirigido modelo de síntese de nanotubos de Ouro plasmônicos com Absorbância IR Tunable

Uma técnica para funcionalizar e auto-montar macroscópicas Nanopartículas-ligante monocamada Films em substratos sem Modelo

Síntese, Assembléia e Caracterização de monocamada Protected Films nanopartículas de ouro para Eletroquímica monocamada Protein

Templates atomicamente definidos para crescimento epitaxial do Complexo Óxido Filmes Finos

Síntese e desempenho catalítico de ouro intercalados nas paredes de mesoporosos Silica

Síntese e Reacção Química de nanosize monossódico Titanate

Um método simples para o tamanho Síntese controlada de estáveis Oligoméricas Clusters de nanopartículas em condições ambientais

Fabricação de matrizes de periódicos Nanocup ouro usando litografia coloidal

Crescimento de nanoformas dendríticos de ouro em substratos de silício revestidos de nitreto de titânio

Síntese de Nanopartículas de Ouro

In situ Síntese de Nanopartículas de Ouro sem agregação no espaço Interlayer de Layered titanato filmes transparentes

Resumo

Explore mais vídeos

Capítulos neste vídeo

Dirigido modelo de síntese de nanotubos de Ouro plasmônicos com Absorbância IR Tunable

Uma técnica para funcionalizar e auto-montar macroscópicas Nanopartículas-ligante monocamada Films em substratos sem Modelo

Síntese, Assembléia e Caracterização de monocamada Protected Films nanopartículas de ouro para Eletroquímica monocamada Protein

Templates atomicamente definidos para crescimento epitaxial do Complexo Óxido Filmes Finos

Síntese e desempenho catalítico de ouro intercalados nas paredes de mesoporosos Silica

Síntese e Reacção Química de nanosize monossódico Titanate

Um método simples para o tamanho Síntese controlada de estáveis ​​Oligoméricas Clusters de nanopartículas em condições ambientais

Fabricação de matrizes de periódicos Nanocup ouro usando litografia coloidal

Crescimento de nanoformas dendríticos de ouro em substratos de silício revestidos de nitreto de titânio

Síntese de Nanopartículas de Ouro

Um método simples para o tamanho Síntese controlada de estáveis Oligoméricas Clusters de nanopartículas em condições ambientais