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).

Achtung: Immer vorsichtig, wenn Sie mit Chemikalien und Lösungen zu arbeiten. Führen Sie die entsprechenden Sicherheitsmaßnahmen und tragen Handschuhe, Schutzbrille und einen Laborkittel zu allen Zeiten. Beachten Sie, dass Nanomaterialien zusätzliche Gefahren für ihre Bulk-Pendant verglichen haben. 1. Herstellung von Regents <ol><li> Bereiten Sie die Methylviologen wässrige Lösung durch Lösen von 0,0012 g 1,1&#39;-Dimethyl-4,4&#39;-bipyridinium - dichlorid (Methylviologen; MV 2+) in 20 ml Wasser , 0,2 mM MV 2+ zu ergeben. </li><li> Bereiten Sie die Gold (III) -chlorid - wßrigen Lösung durch Auflösen von 0,1050 g Gold (III) Tetrachlorid Trihydrat (HAuCl 4 • 3H 2 O) in 10 ml Wasser , 25 mM HAuCl 4 zu ergeben. </li><li> Bereiten Sie die Natriumborhydrid wässrige Lösung durch Auflösen von 0,03844 g Natriumtetrahydroborat (NaBH 4) in 10 ml Wasser , 100 mM NaBH 4 zu ergeben. </li><li> Bereiten Sie die 2-ammoniumethanethiol wässrige Lösung von dissolving 0,2985 g 2-ammoniumethanethiol Chloridsalz (2-AET +) in 25 ml Wasser zu 100 mM 2-AET +. </li></ol> 2. Synthese von TNS kolloidalen Suspensionen HINWEIS: Titania -Nanoschichten (TNS; Ti 0,91 O 2) wurden hergestellt nach dem bewährten Verfahren zuvor berichtet , 22,23,30. <ol><li> Vorbereiten des Ausgangsmaterials von geschichteten Cäsium Cs Titanat 0,7 Ti 1,825 O 4 durch ein stöchiometrisches Gemisch aus Cs 2 CO 3 Calcinieren (0,4040 g) und TiO 2 (ST-01; 0,5000 g) bei 800 ° C für 20 h 22. Zweimal wiederholen dies. </li><li> Bereiten Sie die protoniert geschichtete Titanat (H 0,7 Ti 1,825 O 4 · H 2 O) durch wiederholtes Behandeln 0,8142 g Cäsium Titanat mit einem HCl (100 mM, 81,42 ml) wässrigen Lösung unter Verwendung eines Schüttlers (300 Hz) für 12 Std. </li><li> Bereiten Sie die abgeblätterten Schicht Titanat (TNS) kolloidale Suspensionen vonRühren des protonierten - Titanat - Pulver (0,0998 g) kräftig (500 Umdrehungen pro Minute) mit 25 ml eines 17 mM Tetrabutylammoniumhydroxid (TBA + OH -) wässrige Lösung für ca. 2 Wochen bei Raumtemperatur unter dunklen Bedingungen. Die resultierende opaleszierende Suspension enthält exfolierten Titandioxid-Nanoschichten (TNS; 1,4 g / L, pH = 11 ~ 12). </li></ol> 3. Synthese von TNS Films 21 <ol><li> Herstellung von TNS Gießfolien (c-TNS) <ol><li> Vorreinigen Glassubstrate (~ 20 x 20 mm 2) durch Ultraschallbehandlung einen Ultraschallreiniger (27 kHz) in 1 M wässrigem Natriumhydroxid (NaOH) für 30 min verwendet wird . </li><li> Spülen Sie die Substrate mit 5-10 ml Reinstwasser (&lt;0,056 uS cm -1). </li><li> Tauchen eines Glassubstrats in einer 0,1 M wässriger Salzsäure (HCl) für 3 min und Spülen mit 5-10 ml Reinstwasser. </li><li> Reinigen Sie die Substrate durch Ultraschallbehandlungen (27 kHz) in reinem Wasser für 1 Stunde, unddann spülen mit reinem Wasser. Dry mit einem Haartrockner für 2-3 min (bis trocken). </li><li> Gegossen, die kolloidale Suspension von TNS auf dem Glassubstrat in 300 &amp; mgr; l Aliquots. </li><li> Trocken bei 60 ° C für 2 h mit einem Trockenofen des c-TNS Film zu ergeben. </li></ol></li><li> Herstellung von Sinter TNS Film (s-TNS) <ol><li> thermische Fixierung der TNS-Komponenten auf dem Glassubstrat (s-TNS-Film), Sinter die erhaltene c-TNS-Film in Luft bei 500 ° C für 3 Stunden (Heizen 25-500 ° C bei einer Rate von 6,8 ° C zu erreichen, / min) mit dem Ofen. </li><li> Wiederholen Sie den Sinterprozess zweimal. </li></ol></li><li> Herstellung von Folien <ol><li> Wenn die s-TNS Filme in Lösung eingetaucht sind, positionieren Sie den abgeschiedenen s-TNS Film so, dass sie die oben für alle experimentellen Verfahren steht. </li><li> Führen Sie alle Experimente unter dunklen Bedingungen für den Aufbau mit Aluminiumfolie die Photoreaktion von TNS zu vermeiden. </li></ol></li><li> Vorreitung von Methylviologen (MV 2+) Interkalierte TNS Films (TNS / MV 2+) <ol><li> Tauchen Sie ein s-TNS - Film in einer wässrigen Lösung von MV 2+ Dichloridsalz (0,2 mm, 3 ml) in einer Petrischale für 7 Stunden bei Raumtemperatur (RT) unter dunklen Bedingungen. </li><li> Spülen Sie die erhaltenen Proben mit Reinstwasser (5-10 ml) und trocken in der Luft bei 60 ° C einen Ofen in der Dunkelheit mit für ~ 1 Std. </li></ol></li><li> Herstellung von Au (III) Interkalierte TNS Films (TNS / Au (III)) <ol><li> Tauchen Sie ein TNS / MV 2+ Film in einer wässrigen Lösung von HAuCl 4 (25 mM, 3 ml) in einer Petrischale für 3 h bei RT unter dunklen Bedingungen. </li><li> Spülen Sie die erhaltenen Proben mit Reinstwasser (5-10 ml) und trocken in der Luft bei 60 ° C einen Ofen in der Dunkelheit mit für ~ 1 Std. </li></ol></li><li> Synthese von AuNP innerhalb zwischen die Schichten von TNS Films (TNS / AuNP) <ol><li> Tauchen eine TNS / Au (III) -Film in einer wässrigen Lösung von NaBH 4 </sub&gt; (0,1 M, 5 ml) in einer 0,5 Stunden bei RT unter dunklen Bedingungen Petrischale. </li><li> Trocknen der erhaltenen Folien in Luft bei 60 ° C unter Verwendung eines Ofens in der Dunkelheit für ca. 1 Std. </li></ol></li><li> Herstellung von 2-AET + Intercalated TNS Films (TNS / 2-AET +) <ol><li> Tauchen eine s-TNS - Film in einer wässrigen Lösung von 2-AET + Cl - (0,1 M, 3 ml) in einer Petrischale für 24 h bei RT. </li><li> Spülen erhaltenen Filme mit Reinstwasser (5-10 ml) und trocken bei 60 ° C in Luft für ca. 1 Stunde einen Ofen in der Dunkelheit verwendet wird. </li></ol></li><li> Au (III) und 2-AET + Co-Interkalierte TNS Films (TNS / 2-AET + / Au (III)). <ol><li> Tauchen eine TNS / 2-AET + Film in einer wßrigen Lösung von HAuCl 4 (25 mM, 3 ml) für 3 h bei RT. </li><li> Spülen Sie die erhaltenen Filme mit Reinstwasser (5-10 ml) und trocken in der Luft bei 60 ° C einen Ofen in der Dunkelheit mit für ~ 1 Std. </li></ol></li><li> Synthese von AuNP within zwischen die Schichten von TNS / 2-AET + Films (TNS / 2-AET + / AuNP). <ol><li> Tauchen Sie ein TNS / 2-AET + / Au (III) -Film in einer wässrigen Lösung von NaBH 4 (0,1 M, 5 ml) in einer Petrischale für 0,5 Stunden bei RT unter dunklen Bedingungen. </li><li> Spülen Sie die erhaltenen Filme mit Reinstwasser (5-10 ml) und trockne an der Luft bei 60 ° C für ~ 1 Stunde Ofen in der Dunkelheit verwendet wird. </li></ol></li><li> Charakterisierungen <ol><li> Durchführung von Röntgenbeugung (XRD) analysiert 21 mit einem Desktop - Röntgendiffraktometer mit monochromatisierten Cu-K α - Strahlung (λ = 0,15405 nm), betrieben bei 30 kV und 15 mA. </li><li> Nehmen Sie Energie Röntgenspektroskopie (EDS) Spektren 21. </li><li> Verwenden einen mehrkanaligen Photodetektor oder steady-state ultraviolett-sichtbar (UV-Vis) Absorptions - Spektrophotometer UV-Vis - Absorptionsspektren für die hergestellten Proben unter Verwendung von Transmissionsmodus 21 aufzunehmen. </li></ol></li></ol>

We have nothing to disclose.

Diese Handschrift ein detailliertes Protokoll für die in situ - Synthese von Goldnanopartikeln (AuNPs) innerhalb des Zwischenraums von TNS - Filme. Dies ist der erste Bericht über die in situ Synthese von AuNPs innerhalb des Zwischenraums von TNS. Außerdem fanden wir , dass die 2-AET + arbeitet als wirksame Schutz Reagenz für AuNPs innerhalb der Zwischenschicht von TNS. Diese Verfahren hybridisiert AuNPs und TNS transparente Folien. TNS Filme mit guter optischer Transparenz 21...

Verschiedene Edelmetall-Nanopartikel (MNP) zeigen charakteristische Farben oder Töne aufgrund ihrer lokalisierten Oberflächenplasmonenresonanz (LSPR) Eigenschaften; Somit kann MNP 1-4 in verschiedenen optischen und / oder photochemische Anwendungen verwendet werden. Kürzlich sind Kombinationen von Metalloxid-Halbleiter (MOS) Photokatalysatoren, wie Titanoxid (TiO 2) und MNPs wurden neue Typen von Photokatalysatoren 5-14 gründlich untersucht. Jedoch in vielen Fällen sehr geringe Mengen an MNPs existieren auf der MOS Oberfläche, weil die meisten MOS-Partikel relativ niedrigen Oberflächenbereiche aufweisen. Auf der anderen Seite, geschichteten Metalloxid - Halbleiter (LMOSs) photokatalytischen Eigenschaften aufweisen und eine große Oberfläche haben, in der Regel mehrere hundert Quadratmeter pro Einheit g eines LMOS 15-17. Darüber hinaus haben verschiedene LMOSs Interkalation Eigenschaften (dh verschiedene chemische Spezies innerhalb ihrer ausdehnbaren und großen Zwischenräumen untergebracht werden) 15-20. Somit kann mit einer Kombination von MNP und LMOSs, wird erwartet, dass relativ große Mengen an MNPs mit den Halbleiterphotokatalysatoren hybridisiert werden. (; TNS 16-30 Titandioxid Nanoschicht) transparente Folien durch sehr einfachen Schritten Wir haben die erste in situ Synthese von Kupfer - Nanopartikeln (CuNPs) 21 innerhalb der Zwischenraum von LMOS berichtet. Allerdings haben die Einzelheiten der Syntheseverfahren und die Charakterisierung der anderen edlen MNPs und TNS-Hybriden noch nicht berichtet worden. Darüber hinaus wurden die CuNPs innerhalb der TNS Schichten leicht oxidiert und entfärbt unter Umgebungsbedingungen 21. Als solche konzentrierten wir uns auf Gold - Nanopartikel (AuNPs), da AuNPs weithin für verschiedene optische, photo verwendet werden und katalytische Anwendungen, und es wird erwartet , dass sie gegen Oxidation relativ stabil sein wird 3-5,7,8,10-14 , 28,31,32. Hier berichten wir über die Synthese von AuNPs im Zwischenraum von TNS und zeigen that 2-ammoniumethanethiol (2-AET + Abbildung 1 kleines Bild) arbeitet effektiv als Schutz Reagenz für AuNPs in der Zwischenschicht von 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.

Zwei Arten von Vorläuferfilme wurden in dieser Studie (dh mit und ohne Schutz Reagenz (2-AET +) in der Zwischenschicht von TNS) verwendet. In Abwesenheit von 2-AET +, 1,1&#39;-Dimethyl-4,4&#39;-bipyridinium - dichlorid (Methylviologen; MV 2+) wurde als Expansions des Zwischenraums verwendet, da MV 2+ -haltigen LMOSs gewesen häufig als Zwischenprodukte bei der Gastaustausch Methode zur Herstellung von LMOSs 16,17,21,33-36. ...

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

Hier stellen wir ein Protokoll für die in situ - Synthese von Goldnanopartikeln (AuNPs) innerhalb des Zwischenraums von geschichtetem Titanat - Filmen ohne die Aggregation von AuNPs. Keine spektrale Änderung wurde beobachtet, auch nach 4 Monaten. Das synthetisierte Material hat Anwendungen in der Katalyse, Photokatalyse und die Entwicklung von kosteneffektiven plasmonic Geräte erwartet.

In - situ - Synthese von Gold - Nanopartikeln ohne Aggregation zwischen die Schichten von Layered - Titanat OHP - Folien

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 Aufrufe.  Niigata University.  Hier stellen wir ein Protokoll für die in situ - Synthese von Goldnanopartikeln (AuNPs) innerhalb des Zwischenraums von geschichtetem Titanat - Filmen ohne die Aggregation von AuNPs. Keine spektrale Änderung wurde beobachtet, auch nach 4 Monaten. Das synthetisierte Material hat Anwendungen in der Katalyse, Photokatalyse und die Entwicklung von kosteneffektiven plasmonic Geräte erwartet. 

Serie: 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.

Template Gezielte Synthese von Plasmonic Gold-Nanoröhren mit einstellbaren IR Absorption

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

Forschung

Chemie

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.

Eine Technik, um auf Vorlage freie Substrate zu funktionalisieren und Selbstorganisation makroskopische Nanopartikel-Liganden-Monolayer Films

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).

Synthesis, Assembly und Charakterisierung von Monolayer Protected Gold-Nanopartikeln Films für die Protein-Monoschicht Elektrochemie

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

Biotechnik

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.

Synthese und katalytische Aktivität von Gold-Intercalated in den Wänden der mesoporösen Silicat-

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.

Gold Nanostar Synthesis mit einem Silver Seed vermitteltes Wachstum Methode

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.

Synthese und Reaktionschemie von nanoskaligen Mononatrium Titanat

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.

Eine einfache Methode für die Größe kontrollierte Synthese von stabilen Oligomere Cluster von Goldclustern unter Umgebungsbedingungen

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.

Großflächige Substrat-basierte Nanofabrikation von steuerbaren und anpassbare Gold-Nanopartikeln über angeschnittene Ärmel Dewetting

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

Ingenieurwesen

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.

Wachstum von Gold Dendritic Nanoforests auf Titannitus Nitrium beschichtetem Silizium-Substrat

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.