Dr. B.P.S. Chauhan would like to gratefully acknowledge William Paterson University for assigned release time (ART) award for part of the research described here and also for the research program in general.

Nota: Todos os reagentes são utilizados como é do fabricante, sem purificação adicional. As reacções foram monitorizadas por até uma semana por meio de espectroscopia de UV-Vis, para assegurar a redução completa. Todas as reacções são realizadas sob um capuz de ventilação e vestuário de segurança apropriado é usado em todos os momentos, incluindo luvas, óculos de olho, e jalecos. 1. Síntese de nanopartículas de prata <ol><li> Pesar 0,0169 g (0,1 mmol) de nitrato de prata directamente para um frasco de 50 ml de Erlenmeyer. </li><li> Adicionar em 20 ml de 18,2 mohms de água ultrapura e uma barra de agitação magnética. Cobrir garrafa com rolha para evitar a evaporação. </li><li> Colocar o balão num banho de óleo situado numa placa de agitação / quente e garantir que a temperatura é mantida a 60 ° C. </li><li> Adiciona-se lentamente 144 ul (0,2 mmol) de 2-AST utilizando uma micropipeta de precisão. pipeta Lavar várias vezes em solução para assegurar todo o silano é transferido para a solução. </li><li> Fazer leituras de espectroscopia UV-Visde acordo com o protocolo listado na secção 5. </li><li> Após 6 h, remover da amostra do banho de óleo e transferir para um frasco de 20 ml da amostra para armazenamento, MET, FTIR e análise adicional. Nota: Síntese de nanopartículas de ouro e paládio segue o mesmo método e quantidades estequiométricas com a excepção de nanopartículas de ouro que necessitam de 216 ul (0,3 mmol) de 2-AST. A reação pode continuar a produzir nanopartículas para até 2 semanas, mas a taxa não é significativo em comparação com a taxa inicial. </li></ol> 2. Microscópio Eletrônico de Transmissão (TEM) Preparação de Amostras <ol><li> Certifique-se de que a amostra foi arrefecida à temperatura ambiente. </li><li> Coloque uma grelha de cobre revestido de formvar 200 carbono-mesh em um pedaço de papel limpa filtro. </li><li> Usando um 1 ml de plástico Pasteur pipeta, lançou-drop aproximadamente 60 mL da amostra de nanopartículas diretamente na grade. </li><li> Permitir grade para secar por 24 horas antes de imagem. </li><li> Tome imagens TEM de alta resolução com as seguintes condições:10 mA de corrente e 100 kV tensão de aceleração 22. </li></ol> 3. Ressonância Magnética Nuclear (RMN) Preparação da Amostra Nota: Execute NMR à temperatura ambiente. A altas temperaturas sinais podem coalescer, o que degrada a qualidade dos espectros obtidos. <ol><li> Usando uma pipeta de precisão, pipeta 50 ul de dióxido de deutério (D 2 O) para um tubo de RMN limpo. </li><li> Com outra pipeta de precisão limpo, pipeta de 400 mL de amostra de nanopartículas para o mesmo tubo de RMN. <ol><li> Dado que as amostras podem aderir às paredes internas do tubo de RMN, adicionar lentamente soluções no tubo de RMN. Se a amostra não aderem, a tampa do tubo e apertar a parte superior do tubo para forçar a solução para a parte inferior. </li></ol></li><li> Misturar a amostra por agitação e repetidamente invertendo o tubo de RMN. </li><li> tubo de amostra lugar na RMN seguindo as instruções estabelecidas pelo protocolo de RMN fornecido pelo fabricante. Uma para cima de 1.000 exames podem ser necessários para res adequadoslução num programa de pulso de NMR de protão 1 h. Nota: paredes do tubo NMR devem estar limpas. Recomenda-se que a parede exterior do tubo é limpo com uma microfibra ou um pano sem pêlos antes da análise por espectros de clareza. </li><li> Descarte amostra quando terminar. Não devolva amostra a solução-mãe. </li></ol> 4. Fourier Transform Infrared Preparação de Amostras (FTIR) Espectroscopia <ol><li> Coloque 2 ml de amostra de nanopartículas em um recipiente de vidro pequeno. A 3 tubo ml ou 1 dram frasco de vidro funciona bem. </li><li> Secam-se as amostras colocando-se o recipiente de vidro num exsicador de vácuo equipado com uma torneira de passagem. </li><li> Anexar exsicador até aparelhos bomba de vácuo. Secagem de amostras pode demorar algumas horas, dependendo da força do vácuo. amostras considerar secar depois não há líquido visível no recipiente. </li><li> Raspe a amostra usando uma espátula limpa e recolher materiais sólidos. </li><li> Coloque material sólido em ATR-FTIR espectroscópio equipado com um cryst ZnSeai diodo laser. </li><li> Obter espectros FTIR integrando 32 varrimentos entre 4,000-500 cm -1 com uma resolução espectral de 2,0. Use o fundo de ar 23. </li></ol> 5. espectroscopia UV-vis Preparação da Amostra <ol><li> Realizar espectroscopia UV-vis em amostras de nanopartículas que se encontram numa diluição de 9:59 da amostra de nanopartículas à água de modo que a saturação não ocorre na análise espectrómetro. </li><li> Retirar amostras de nanopartículas de UV-Vis enquanto que a reacção está sendo executado em intervalos de meia hora. </li><li> Usando uma pipeta de precisão, remover 100 ul de material de nanopartículas e colocar numa cuvete de plástico. </li><li> Adicionar 1 ml de água ultrapura para a mesma tina e misture bem por liberando a pipeta várias vezes. </li><li> UV-Vis espectro de absorção recorde entre 250-800 nm. </li><li> Após a análise, não retornam amostra a reação. Dispor de analito de uma maneira apropriada. </li></ol>

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Sais relatados neste trabalho são as únicas sais que foram testados desse metal. Como resultado, não é certo que esta estratégia reacção iria trabalhar com todos os sais de metais, particularmente ouro. A solubilidade destes sais em água podem também afectar o resultado da reacção em termos de tempo de reacção, morfologia, e os rendimentos. Em todas as reacções, o silano foi adicionado a uma solução de sal de metal já dissolvido. É importante notar que é preciso ter cuida...

Como a demanda e aplicações de designer de nanomateriais aumenta, o mesmo acontece com os vários métodos de síntese. Os métodos de &quot;cima para baixo&quot;, como a ablação a laser ou ataque químico têm sido empregadas por sua excelente controlabilidade e capacidade de resolver os materiais de forma confiável até o nível sub-micron. Estes métodos baseiam-se em materiais a granel a ser processado em componentes mais finas, que tipicamente aumentam o custo de produção, como o tamanho desejado nanoestrutura diminui. Um método alternativo de síntese para isso é a abordagem &quot;bottom-up&quot;, que controla a síntese, a nível molecular e acumula-se à nanoestrutura desejado. Isto confere um grau significativo de controle sobre a auto-montagem desejada, a funcionalidade, a passividade, e estabilidade na geração destes materiais nanoestruturados 1. Ao trabalhar a partir do nível molecular, nanocompósitos híbridos pode ser gerado fornecendo as vantagens de ambos os materiais na mesma estruturé. Como nanomateriais são sintetizados através da estratégia de baixo para cima, métodos precisam ser empregadas para controlar o tamanho das partículas, forma, textura, hidrofobicidade, porosidade, carga e funcionalidade 2. Na síntese de nanopartículas núcleo de metal, o sal de metal inicial for reduzida em um processo autocatalítico, para gerar partículas de valência zero, o que por sua vez, dirigem a nucleação de outra partícula. Isto leva a agrupamento e produção de nanopartículas, finalmente, 3. Num esforço para controlar o tamanho das nanopartículas criadas e impedi-los de precipitar a partir da solução, estabilizadores, tais como ligantes, agentes tensioactivos, carga iónica, e polímeros grandes são explorados quanto à sua capacidade para bloquear as nanopartículas de outra aglomeração 4-10. Estes materiais inibem a atracção de van der Waals das nanopartículas, quer através de impedimento espacial, devido à presença de grupos volumosos ou através repulsões Coulomb 3. em tseu trabalho, uma, uma panela, a estratégia de síntese simples para a geração de várias nanopartículas núcleo de metal usando o silano, N- (2-aminoetil) -3-aminosilanetriol (2-AST) é apresentada (Figura 1). Ligandos sobre este composto é capaz de reduzir os precursores de metal e estabilizar as nanopartículas metálicas com uma relativamente alta eficácia. As três porções de silanol presentes também são capazes de ligação cruzada e isto forma uma rede interligada de polímero impregnado com nanopartículas organossilano numa sua matriz (Figura 2). Ao contrário da maioria silanos, que facilmente sujeitos a hidrólise na presença de água, este composto é estabilizado em água, o que é benéfico para fins de hidrofobicidade, estabilidade e controlo.

<table><tbody><tr><td>n-(2-aminoethyl)-3-aminosilanetriol (2-AST)</td><td>Gelest</td><td>SIA0590.0</td><td>25% in H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>Silver nitrate</td><td>Sigma Aldrich</td><td>S6506</td><td></td></tr><tr><td>Gold(III) chloride trihydrate</td><td>Sigma Aldrich</td><td>520918</td><td></td></tr><tr><td>Palladium(II) Nitrate</td><td>Alfa Aesar</td><td>11035</td><td></td></tr><tr><td>Deuterium Dioxide</td><td>Cambridge Isotope Laboratories</td><td>DLM-4-100</td><td></td></tr></tbody></table>

generation of zerovalent metal core nanoparticles using n-(2-aminoethyl)-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.

A reacção foi monitorizada através de espectrometria de UV-Vis de formação de nanopartículas deve produzir picos característicos para cada indivíduo nanopartículas metálicas. A análise final dos materiais sintetizados foi realizada através de TEM e FTIR. Os espectros de FTIR foi obtido a partir de pó seco de amostras. A análise do tamanho de partícula pode ser realizada por medição de diâmetro de nanopartículas de imagens obtidas através de TEM e os resultados médios...

Watch this Scientific Journal Video about Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol at JoVE.com

Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

Geração de valência zero Metal Core nanopartículas utilizando N- (2-aminoetil) -3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of ...

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Chemistry

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol

7.6K visualizações.  William Paterson University. A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

Vídeo: Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

Química

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.

Síntese Nanostar ouro com um método de crescimento de sementes de Prata 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 ...

Bioengenharia

Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

We present a template-free method for &#8220;polymerizing&#8221; nanoparticles into long chains without side branches. A variety of nanoparticles are encapsulated in polystyrene-block-poly(acrylic acid) (PSPAA) shells and then used as monomers for their self-assembly. Spherical PSPAA micelles upon acid treatment are known to assemble into cylindrical micelles. Exploiting this tendency, the core-shell nanoparticles are induced to aggregate, coalesce, and then transform into long chains. When more than one type of nanoparticles are used, random and block &#8220;copolymers&#8221; of nanoparticles can be obtained. Detailed procedures are reported for the PSPAA encapsulation of nanoparticles, homo- and co-polymerization of the core-shell nanoparticles, separation and purification of the resulting nanoparticle chains. Transformations of single-line chains into double- and triple-line chains are also presented. The synergy between the polymer shell and the embedded nanoparticles leads to an unusual chain-growth polymerization mode, giving long nanoparticle chains that are distinct from the products of the traditional step-growth aggregation process.

Using Polystyrene-block-polyacrylic acid-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

We report protocols for &#8220;polymerizing&#8221; various types of polymer-encapsulated metal nanoparticles into long chains of &#8220;homo-&#8220; and &#8220;co-polymers&#8221;.

Usando Polystyrene-<em&gt; Bloco</em&gt; -poli (Ácido acrílico) -Revestido metal Nanopartículas como monómeros para a sua homo- e co-polimerização

We present a template-free method for &#8220;polymerizing&#8221; nanoparticles into long chains without side branches. A variety of nanoparticles are ...

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

Inversa Síntese mediada por Microemulsão de monometálicos e bimetálico precoce de Metais de Transição Carbide e nitreto Nanopartículas

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

Síntese, caracterização e funcionalização de híbrida UA / CDS e Au / ZnS Núcleo / Shell Nanopartículas

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Síntese e Caracterização de Supramoleculares Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

A Rapid Synthesis Method for Au, Pd, and Pt Aerogels Via Direct Solution-Based Reduction

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various precursor noble metal ions with reducing agents in a 1:1 (v/v) ratio results in the formation of metal gels within seconds to minutes compared to much longer synthesis times for other techniques such as sol-gel. Conducting the reduction step in a microcentrifuge tube or small volume conical tube facilitates a proposed nucleation, growth, densification, fusion, equilibration model for gel formation, with final gel geometry smaller than the initial reaction volume. This method takes advantage of the vigorous hydrogen gas evolution as a by-product of the reduction step, and as a consequence of reagent concentrations. The solvent accessible specific surface area is determined with both electrochemical impedance spectroscopy and cyclic voltammetry. After rinsing and freeze drying, the resulting aerogel structure is examined with scanning electron microscopy, X-ray diffractometry, and nitrogen gas adsorption. The synthesis method and characterization techniques result in a close correspondence of aerogel ligament sizes. This synthesis method for noble metal aerogels demonstrates that high specific surface area monoliths may be achieved with a rapid and direct reduction approach.

A rapid, direct solution-based reduction synthesis method to obtain Au, Pd, and Pt aerogels is presented.

Um método de síntese rápida para Au, Pd e Pt Aerogels através de redução direta baseada em solução

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various ...

Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular physico-chemical properties of ionic liquids (ILs) are exploited to control both nucleation and growth processes. The nanoparticles form colloidal sols of very high colloidal stability in the IL, which is particularly interesting in view of their use as quasi-homogeneous catalysts. Procedures for both nanoparticle extraction in conventional solvents and for nanoparticle precipitation are presented. The size, structure and composition of the synthesized nanocrystals are confirmed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX). By this, we show that the nanocrystals are random-type alloy and of small (2-3 nm) size. The catalytic activity and selectivity in the hydrogenation of &#945;,&#946;-unsaturated aldehydes is tested in a semi-continuous batch-type reactor. In this context, the bimetallic Pt/Sn-based nanoparticles reveal a high selectivity towards the unsaturated alcohol.

A protocol for the synthesis of bimetallic nanoparticles in ionic liquids and the procedure of their catalytic testing in the selective hydrogenation of unsaturated aldehydes are described.

Síntese de Nanopartículas Bimetálicas à Base de Pt/Sn em Líquidos Iônicos

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular ...

Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium

The goal of this protocol is to describe the synthesis of two novel biocomposites with high-aspect ratio structures. The biocomposites consist of copper and cystine, with either copper nanoparticles (CNPs) or copper sulfate contributing the metallic component. Synthesis is carried out in liquid under biological conditions (37 &#176;C) and the self-assembled composites form after 24 hr. Once formed, these composites are highly stable in both liquid media and in a dried form. The composites scale from the nano- to micro- range in length, and from a few microns to 25 nm in diameter. Field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (EDX) demonstrated that sulfur was present in the NP-derived linear structures, while it was absent from the starting CNP material, thus confirming cystine as the source of sulfur in the final nanocomposites. During synthesis of these linear nano- and micro-composites, a diverse range of lengths of structures is formed in the synthesis vessel. Sonication of the liquid mixture after synthesis was demonstrated to assist in controlling average size of the structures by diminishing the average length with increased time of sonication. Since the formed structures are highly stable, do not agglomerate, and are formed in liquid phase, centrifugation may also be used to assist in concentrating and segregating formed composites.

Here we present a protocol to synthesize novel, high-aspect ratio biocomposites under biological conditions and in liquid media. The biocomposites scale from nanometers to micrometers in diameter and length, respectively. Copper nanoparticles (CNPs) and copper sulfate combined with cystine are the key components for the synthesis.

Geração de escalável e de alto-Aspect Metallic nanocompósitos índices, em um Biológico Líquido Médio

The goal of this protocol is to describe the synthesis of two novel biocomposites with high-aspect ratio structures. The biocomposites consist of copper ...

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.

Geração de valência zero Metal Core nanopartículas utilizando N- (2-aminoetil) -3-aminosilanetriol

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