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).

Attenzione: Usare sempre cautela quando si lavora con sostanze chimiche e soluzioni. Seguire le procedure di sicurezza appropriate e indossare guanti, occhiali, e un camice da laboratorio in ogni momento. Essere consapevoli del fatto che i nanomateriali possono avere rischi aggiuntivi rispetto alla loro controparte di massa. 1. Preparazione di Regents <ol><li> Preparare la soluzione di metile viologeno acquosa sciogliendo 0,0012 g di dicloruro 1,1&#39;-dimetil-4,4&#39;-bipiridinio (metil viologeno; MV 2+) in 20 ml di acqua per dare 0,2 mM MV 2+. </li><li> Preparare l&#39;oro (III) soluzione acquosa di cloruro sciogliendo 0,1050 g di oro (III) tetracloruro triidrato (HAuCl4 • 3H 2 O) in 10 ml di acqua per dare 25 mM HAuCl4. </li><li> Preparare la soluzione di boroidruro di sodio acquoso sciogliendo 0,03,844 mila g di boroidruro di sodio (NaBH4) in 10 ml di acqua per dare 100 mM NaBH 4. </li><li> Preparare la soluzione acquosa 2-ammoniumethanethiol da dissolving 0,2985 g di 2-ammoniumethanethiol cloruro di sale (2-AET +) in 25 ml di acqua per dare 100 mm 2-AET +. </li></ol> 2. Sintesi di TNS colloidali Sospensioni NOTA: nanosheets Titania (TNS; Ti 0,91 O 2) sono stati preparati secondo la procedura consolidata riportato in precedenza 22,23,30. <ol><li> Preparare il materiale di partenza di stratificato cesio Cs titanato 0,7 Ti 1.825 O 4 per calcinazione di una miscela stechiometrica di Cs 2 CO 3 (0,4040 g) e TiO 2 (ST-01; 0.5000 g) a 800 ° C per 20 ore 22. Ripetere questo due volte. </li><li> Preparare il titanato stratificato protonato (H 0,7 Ti 1.825 O 4 · H 2 O) trattando ripetutamente 0,8142 g di cesio titanato con HCl (100 mM, 81.42 ml) soluzione acquosa con un agitatore (300 Hz) per 12 hr. </li><li> Preparare il titanato strati espansa (TNS) sospensioni colloidali dimescolare la polvere protonato titanato (0,0998 g) determinazione (500 rpm) con 25 ml di idrossido di tetrabutilammonio 17 mM (TBA + OH -) soluzione acquosa per circa 2 settimane a temperatura ambiente in condizioni di oscurità. La sospensione opalescente risultante contiene espansa nanosheets Titania (TNS; 1,4 g / L, pH = 11 ~ 12). </li></ol> 3. Sintesi di TNS Cinema 21 <ol><li> Preparazione di TNS gettato film (c-TNS) <ol><li> Pre-pulire substrati di vetro (~ 20 x 20 mm 2) attraverso trattamenti ad ultrasuoni utilizzando un bagno ad ultrasuoni (27 kHz) in 1 M di idrossido di sodio acquoso (NaOH) per 30 min. </li><li> Sciacquare i substrati con 5-10 ml di acqua ultrapura (&lt;0,056 microsiemens per cm -1). </li><li> Immergere un substrato di vetro in 0,1 M di acido cloridrico acquoso (HCl) per 3 minuti e risciacquare con 5-10 ml di acqua ultrapura. </li><li> Pulire i substrati attraverso trattamenti ad ultrasuoni (27 kHz) in acqua pura per 1 ora, epoi sciacquare con acqua pura. Asciugare con un asciugacapelli per 2-3 minuti (fino a secco). </li><li> Cast la sospensione colloidale di TNS sul substrato di vetro in 300 microlitri aliquote. </li><li> Lavaggio a 60 ° C per 2 ore utilizzando un forno a secco per dare al film c-TNS. </li></ol></li><li> Preparazione di sinterizzato TNS Film (s-TNS) <ol><li> Per ottenere una fissazione termica dei componenti TNS sul substrato di vetro (s-TNS film), sinterizzazione il film c-TNS ottenuto in aria a 500 ° C per 3 ore (riscaldamento da 25 a 500 ° C ad una velocità di 6,8 ° C / min) utilizzo del forno. </li><li> Ripetere il processo di sinterizzazione due volte. </li></ol></li><li> Preparazione di Films <ol><li> Quando il film s-TNS sono immersi in soluzione, posizionare il film s-TNS depositato in modo che sia rivolto verso l&#39;alto per tutte le procedure sperimentali. </li><li> Effettuare tutti gli esperimenti in condizioni di oscurità coprendo l&#39;installazione con un foglio di alluminio per evitare l&#39;fotoreazione di TNS. </li></ol></li><li> Preparazione di metile viologeno (MV 2+) Intercalated TNS Films (TNS / MV 2+) <ol><li> Immergere un film s-TNS in una soluzione acquosa di MV 2+ sale dicloruro (0,2 mM, 3 ml) in una piastra di Petri per 7 ore a temperatura ambiente (RT) in condizioni di oscurità. </li><li> Risciacquare campioni ottenuti con acqua ultrapura (5-10 ml) ed essiccare all&#39;aria a 60 ° C utilizzando un forno al buio per ~ 1 ora. </li></ol></li><li> Preparazione di Au (III) Intercalated TNS Films (TNS / Au (III)) <ol><li> Immergere un TNS / MV 2+ pellicola in una soluzione acquosa di HAuCl4 (25 mM, 3 ml) in una piastra di Petri per 3 ore a temperatura ambiente in condizioni di oscurità. </li><li> Risciacquare campioni ottenuti con acqua ultrapura (5-10 ml) ed essiccare all&#39;aria a 60 ° C utilizzando un forno al buio per ~ 1 ora. </li></ol></li><li> Sintesi di AUNP entro l&#39;intercalare spazio di TNS Films (TNS / AUNP) <ol><li> Immergere un film TNS / Au (III) in una soluzione acquosa di NaBH4 </sub&gt; (0,1 M, 5 ml) in una capsula di Petri per 0,5 ore a temperatura ambiente in condizioni di oscurità. </li><li> Essiccare i film ottenuti in aria a 60 ° C utilizzando un forno al buio per ~ 1 ora. </li></ol></li><li> Preparazione di 2-AET + Intercalated TNS Films (TNS / 2-AET +) <ol><li> Immergere un film s-TNS in una soluzione acquosa di 2-AET + Cl - (0,1 M, 3 ml) in una piastra di Petri per 24 ore a temperatura ambiente. </li><li> Risciacquare ottenuta film con acqua ultrapura (5-10 ml) ed essiccare all&#39;aria a 60 ° C utilizzando un forno al buio per ~ 1 ora. </li></ol></li><li> Au (III) e 2-AET + Co-Intercalated TNS Films (TNS / 2-AET + / Au (III)). <ol><li> Immergere un film TNS / 2-AET + in una soluzione acquosa di HAuCl4 (25 mM, 3 ml) per 3 ore a temperatura ambiente. </li><li> Risciacquare film ottenuti con acqua ultrapura (5-10 ml) ed essiccare all&#39;aria a 60 ° C utilizzando un forno al buio per ~ 1 ora. </li></ol></li><li> Sintesi di AUNP within Spazio Strato intermedio di TNS / 2-AET + Films (TNS / 2-AET + / AUNP). <ol><li> Immergere un film TNS / 2-AET + / Au (III) in una soluzione acquosa di NaBH 4 (0,1 M, 5 ml) in una piastra di Petri per 0,5 ore a temperatura ambiente in condizioni di oscurità. </li><li> Risciacquare film ottenuti con acqua ultrapura (5-10 ml) ed essiccare all&#39;aria a 60 ° C utilizzando forno nel buio per ~ 1 ora. </li></ol></li><li> caratterizzazioni <ol><li> Eseguire diffrazione di raggi X (XRD) analizza 21 utilizzando un desktop diffrattometro a raggi X con monochromatized α radiazione Cu-K (λ = 0,15,405 mila nm), regolata al 30 kV e 15 mA. </li><li> Prendere a dispersione di energia dei raggi X spettrometria (EDS) spettri 21. </li><li> Impiegare un fotorivelatore multicanale o di stato stazionario ultravioletta-visibile (UV-Vis) spettrofotometro ad assorbimento per registrare spettri di assorbimento UV-Vis per i campioni preparati utilizzando la modalità di trasmissione 21. </li></ol></li></ol>

We have nothing to disclose.

Questo manoscritto fornisce un protocollo dettagliato per la sintesi in situ di nanoparticelle di oro (AuNPs) all&#39;interno dello spazio interstrato di film TNS. Questo è il primo rapporto della sintesi in situ di AuNPs all&#39;interno dello spazio intermedio di TNS. Inoltre, abbiamo scoperto che il 2-AET + funziona come un reagente di protezione efficace per AuNPs entro l&#39;intercalare di TNS. Questi metodi ibridate AuNPs e TNS pellicole trasparenti. Film TNS con buona trasparenza otti...

Vari nanoparticelle di metalli nobili (MNPS) esibire colori caratteristici o toni a causa della loro localizzata plasmonica di superficie (LSPR) proprietà di risonanza; pertanto, MNPs possono essere utilizzati in varie / o applicazioni ottiche e fotochimici 1-4. Recentemente, combinazioni di ossido metallico semiconduttore (MOS) fotocatalizzatori, come l&#39;ossido di titanio (TiO 2) e MNPs, sono state investigate esaurientemente come nuovi tipi di fotocatalizzatori 5-14. Tuttavia, in molti casi, esistono piccole quantità di MNPs sulla superficie MOS, perché la maggior parte delle particelle MOS hanno area superficiale relativamente bassa. D&#39;altra parte, strati semiconduttori di ossido di metallo (LMOSs) esibire proprietà fotocatalitiche e hanno una grande superficie, tipicamente diverse centinaia di metri quadrati per unità g di una LMOS 15-17. Inoltre, varie LMOSs hanno proprietà di intercalazione (ad esempio, varie specie chimiche possono essere ospitati all&#39;interno dei loro spazi interstrato espandibili e grandi) 15-20. Così, con una combinazione di MNPs e LMOSs, si prevede che quantità relativamente elevate di MNPs sono ibridate con i fotocatalizzatori semiconduttori. Abbiamo riportato la prima nella sintesi in situ di nanoparticelle di rame (CuNPs) 21 all&#39;interno dello spazio intercalare di LMOS (Titania nanosheet; TNS 16-30) pellicole trasparenti attraverso passaggi molto semplici. Tuttavia, non sono ancora stati riportati i dettagli delle procedure di sintesi e la caratterizzazione degli altri nobili ibridi MNPS e TNS. Inoltre, le CuNPs all&#39;interno degli strati TNS erano facilmente ossidati e decolorati in condizioni ambientali di 21. Come tale, ci siamo concentrati su nanoparticelle di oro (AuNPs), perché AuNPs sono ampiamente utilizzati per vari ottica, fotochimico, e le applicazioni catalitiche, e si prevede che saranno relativamente stabile contro l&#39;ossidazione 3-5,7,8,10-14 , 28,31,32. Qui, riportiamo la sintesi di AuNPs all&#39;interno dello spazio interstrato di TNS e spettacolo that 2-ammoniumethanethiol (2-AET +; Figura 1 riquadro) funziona in modo efficace come reagente di protezione per AuNPs entro l&#39;intercalare di 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.

Due tipi di film precursori sono stati utilizzati in questo studio (cioè, con e senza il reagente di protezione (2-AET +) all&#39;interno dell&#39;intercalare TNS). In assenza di 2-AET +, 1,1&#39;-dimetil-4,4&#39;-bipiridinio dicloruro (metil viologeno; MV 2+) è stato utilizzato come un espansore dello spazio interstrato, perché MV 2+ -contenente LMOSs stato frequentemente utilizzato come intermedi nella metodo di scambio ospite per...

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

Qui, vi presentiamo un protocollo per la sintesi in situ di nanoparticelle d&#39;oro (AuNPs) all&#39;interno dello spazio intermedio dei film titanato di strati senza l&#39;aggregazione di AuNPs. Nessun cambiamento spettrale è stata osservata anche dopo 4 mesi. Il materiale sintetizzato ha previsto applicazioni in catalisi, fotocatalisi, e lo sviluppo di dispositivi plasmonici convenienti.

In Situ Sintesi di oro nanoparticelle senza aggregazione nel Interfalda spazio di Layered titanato pellicole trasparenti

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

Universidad San Sebastian

Research

JoVE Journal

Engineering

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

8.0K Views.  Niigata University.  Qui, vi presentiamo un protocollo per la sintesi in situ di nanoparticelle d'oro (AuNPs) all'interno dello spazio intermedio dei film titanato di strati senza l'aggregazione di AuNPs. Nessun cambiamento spettrale è stata osservata anche dopo 4 mesi. Il materiale sintetizzato ha previsto applicazioni in catalisi, fotocatalisi, e lo sviluppo di dispositivi plasmonici convenienti. 

Video: 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.

Modello Regia Sintesi di nanotubi d&#39;oro plasmoniche con Tunable Assorbanza IR

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

Ricerca

Chimica

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.

Una tecnica di funzionalizzare e Self-montare macroscopiche nanoparticelle-ligando monostrato Films su substrati privi di modello

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).

Sintesi, assemblaggio e caratterizzazione di film monostrato Protetta delle nanoparticelle d&#39;oro per Elettrochimica proteine ​​monostrato

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

Bioingegneria

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.

Sintesi e prestazioni catalitica dell&#39;oro intercalata nelle Mura di mesoporosi silice

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

Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest in using nano-colloids for photo-thermal ablation, drug delivery and many other biomedical applications 6. Gold is particularly used because of its low toxicity 7-9. A property of metal nano-colloids is that they can have a strong surface plasmon resonance 10. The peak of the surface plasmon resonance mode depends on the structure and composition of the metal nano-colloids. Since the surface plasmon resonance mode is stimulated with light there is a need to have the peak absorbance in the near infrared where biological tissue transmissivity is maximal 11, 12.
We present a method to synthesize star shaped colloidal gold, also known as star shaped nanoparticles 13-15 or nanostars 16. This method is based on a solution containing silver seeds that are used as the nucleating agent for anisotropic growth of gold colloids 17-22. Scanning electron microscopy (SEM) analysis of the resulting gold colloid showed that 70 % of the nanostructures were nanostars. The other 30 % of the particles were amorphous clusters of decahedra and rhomboids. The absorbance peak of the nanostars was detected to be in the near infrared (840 nm). Thus, our method produces gold nanostars suitable for biomedical applications, particularly for photo-thermal ablation.

We synthesized star shaped gold nanostars using a silver seed mediated growth method. The diameter of the nanostars ranges from 200 to 300 nm and the number of tips vary from 7 to 10. The nanoparticles have a broad surface plasmon resonance mode centered in the near infrared.

Sintesi Nanostar oro con un metodo d&#39;argento crescita Seed Mediated

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest ...

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.

Sintesi e Reazione chimica della nanosize monosodico titanato

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.

Un metodo semplice per la dimensione sintesi controllata di stabili oligomeriche Grappoli di oro nanoparticelle in condizioni ambientali

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

Large Area Substrate-Based Nanofabrication of Controllable and Customizable Gold Nanoparticles Via Capped Dewetting

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and high-density data storage have demonstrated the potential benefit of their use in industrial applications. These applications require precise control over nanoparticle size, spacing, and sometimes shape. These requirements have resulted in the use of time and cost intensive processing steps to produce nanoparticles, thus making the transition to industrial application unrealistic. This protocol will resolve this issue by providing a scalable and affordable method for the large-area production of nanoparticle films with improved nanoparticle control compared to the current techniques. In this article, the process will be demonstrated with gold, but other metals can also be used.

This protocol details a novel nano-manufacturing technique that can be used to make controllable and customizable nanoparticle films over large areas based on the self-assembly of dewetting of capped metal films.

Grande Area nanofabbricazione di substrato a base di nanoparticelle di oro controllabile e personalizzabile tramite ridotta bagnabilità

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and ...

Ingegneria

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.

Crescita di Nanoforests dendritiche oro su substrati di silicio rivestiti in nitruro di titanio

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 Sintesi di oro nanoparticelle senza aggregazione nel Interfalda spazio di Layered titanato pellicole trasparenti

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Una tecnica di funzionalizzare e Self-montare macroscopiche nanoparticelle-ligando monostrato Films su substrati privi di modello

Sintesi, assemblaggio e caratterizzazione di film monostrato Protetta delle nanoparticelle d'oro per Elettrochimica proteine monostrato

Sintesi e prestazioni catalitica dell'oro intercalata nelle Mura di mesoporosi silice

Sintesi Nanostar oro con un metodo d'argento crescita Seed Mediated

Sintesi e Reazione chimica della nanosize monosodico titanato

Un metodo semplice per la dimensione sintesi controllata di stabili oligomeriche Grappoli di oro nanoparticelle in condizioni ambientali

Grande Area nanofabbricazione di substrato a base di nanoparticelle di oro controllabile e personalizzabile tramite ridotta bagnabilità

Crescita di Nanoforests dendritiche oro su substrati di silicio rivestiti in nitruro di titanio

Sintesi della nanoparticella d'oro

In Situ Sintesi di oro nanoparticelle senza aggregazione nel Interfalda spazio di Layered titanato pellicole trasparenti

Riepilogo

Esplora Altri Video

Capitoli in questo video

Modello Regia Sintesi di nanotubi d'oro plasmoniche con Tunable Assorbanza IR

Una tecnica di funzionalizzare e Self-montare macroscopiche nanoparticelle-ligando monostrato Films su substrati privi di modello

Sintesi, assemblaggio e caratterizzazione di film monostrato Protetta delle nanoparticelle d'oro per Elettrochimica proteine ​​monostrato

Sintesi e prestazioni catalitica dell'oro intercalata nelle Mura di mesoporosi silice

Sintesi Nanostar oro con un metodo d'argento crescita Seed Mediated

Sintesi e Reazione chimica della nanosize monosodico titanato

Un metodo semplice per la dimensione sintesi controllata di stabili oligomeriche Grappoli di oro nanoparticelle in condizioni ambientali

Grande Area nanofabbricazione di substrato a base di nanoparticelle di oro controllabile e personalizzabile tramite ridotta bagnabilità

Crescita di Nanoforests dendritiche oro su substrati di silicio rivestiti in nitruro di titanio

Sintesi della nanoparticella d'oro

Sintesi, assemblaggio e caratterizzazione di film monostrato Protetta delle nanoparticelle d'oro per Elettrochimica proteine monostrato