The authors acknowledge National Science Foundation grant CHE- 1214068 for supporting this research project.

1.准备大湄公河次区域<ol><li>使用所有的化学品，在以下的处理作为接收。 </li><li>制备75毫升的盐酸（HCl）溶液的2M。权衡将2.0g聚（乙二醇） - 嵌段 - 聚（丙二醇） - 嵌段 - 聚（乙二醇）（P123，MW = 5800），并转移到制备75的2M盐酸溶液。在RT，应用磁力搅拌的溶液在350转/分的速度，直至P123完全溶解。该解决方案将是明确的。 </li><li>权衡4克四乙氧基硅烷（TEOS，MW = 208.33）在一个小瓶和转让180微升双[3-（三乙氧基甲硅烷基）丙基] - 四硫化物（TESPTS，MW = 538.94）到小瓶。慢摇瓶中混合使用这两种化学物质。在另一个小瓶中，称取38毫克氯金酸的（氯金酸4，99.90％）和溶解在1ml去离子水中。 </li><li>增加的P123溶​​液温度至35℃的油浴温度由热电偶控制。 </li><li>添加所有加入的TEOS的混合物和在步骤1.3至P123溶​​液制备TESPTS，并保持溶液在700转/分钟剧烈磁力搅拌。保持该溶液搅拌2分钟，然后加入所有的在30秒内制备，在步骤1.3滴加氯金酸4溶液。 </li><li>保持溶液在700转/分在35℃下搅拌24小时。 </li><li> 24小时后，转移在一个烘箱中在100℃下进行72小时的溶液到一个密封的瓶子，并存储。这就是所谓的水热加工。 </li><li>热液处理后，进行过滤以＃1过滤纸和负压下的溶液的漏斗，然后用水洗涤两次，乙醇三次，以除去剩余的HCl。在每次洗涤过程中，加水或乙醇上方1厘米的固体，并等待该材料干燥。 </li><li>从过滤转移沉淀到陶瓷坩埚中并煅烧在550℃进行4小时。设置斜坡程序如下:25℃〜550℃进行2小时，保持在550℃下进行4小时，然后使样品保留在炉中的门关闭，直到温度下降到低于40℃。 </li><li>煅烧后，将产物用塑料刮铲转移至玻璃小瓶中。合成材料具有红色。 </li></ol> 2.催化反应，苯甲醇的氧化<ol><li>自苄醇的氧化是没有单独的溶剂的液相反应，测量5毫升苄醇（99.8％），并将其转移到25毫升三颈烧瓶中，然后称重10毫克GMS催化剂并将其添加到苯酒精。 </li><li>设置了温度控制的油浴中磁搅拌，以保证反应温度精确和均匀的控制。 </li><li>放与苄醇及催化剂的烧瓶放入油浴中，然后将温度设置为100℃，搅拌，在150转/分。 </li><li>流动氧气与99.9％纯度到烧瓶中以2毫升/分钟通过一个质量流量控制器控制。 </li><li>当...的时候将油浴温度达到100℃并稳定时，引入的氧气进入三颈烧瓶中。 </li><li>保持氧气流率和温度恒定，并允许反应进行6小时。 </li><li>反应后，过滤该产物与＃1过滤纸。收集液相和等分试样转移到气相色谱（GC）小瓶中。在GC小瓶中，混合四部分HPLC级乙酸，每一个部分样品（例如，使用36微升样品和144微升乙酸。）将小瓶上气相色谱自动取样用于分析。上用DI水和乙醇在滤纸洗掉固体沉淀物，然后允许在空气中干燥。收集干燥的固体用刮铲作为再循环催化剂。 </li><li>通过2.7使用回收的催化剂三次重复步骤2.3相同的实验过程。在每个重复，调整苄醇的量，以在步骤2.2中所述的比率匹配。 </li></ol> 3.疗法大湄公河次区域的发作治疗热稳定性的测试<ol><li>权衡合成GMS三个独立300mg的部分，并且将它们存储在玻璃小瓶中。这些被标记为1批，第2批和批3.保持1批为对照组，并把第2批和第3批入炉热加工。 </li><li>程序作为在400℃以下进行处理炉:在0.5小时斜坡从25℃至400℃，在400℃下保持4小时，使样品保持与门的炉关闭，直到温度瀑布低于40℃。把第2批中的坩埚，并启动该程序。 </li><li>程序作为在650℃以下进行处理炉:在0.75小时斜坡从25℃至650℃，在650℃下保持4小时，使样品保留在炉中门关闭，直到下面的温度下降40℃。把批3中的坩埚，并启动该程序。 </li></ol> 4.表征GMS材料21,22 <ol><li>上的物理吸附仪器，脱气GMS材料与以下程序:90℃60分钟，然后350℃，480分钟。运行在脱气材料全等温线的分析来获得物理吸附数据。 </li><li>分散GMS样品上200目多孔碳TEM网格并观察透射型电子显微镜下的样品。限制44,000X放大倍率下，以保护材料。 </li><li>运行的XRD用CuKα射线（λ= 1.5418）。集管电压为45kV，和40毫安管电流。收集强度在2θ范围在10°和90°与0.008°的步长和5秒的每一步的测量时间。 </li></ol>

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The authors have nothing to disclose.

内的合成方案，关注的表面活性剂的浓度，pH值的溶液中，反应温度是在成功形成GMS是至关重要的。关键步骤是1.2，1.3，1.4和1.6。上述参数控制从表面活性剂形成的胶束的临界堆积参数和相位。胶束的相位和形态确定二氧化硅基质，将成为用于GMS框架的最终状态。另外，在形成过程中重要的是该序列和时间添加氯金酸溶液。 TEOS和TESPTS分别作为二氧化硅源和表面改性剂。加入两种化学物质首先确保...

作为一项新兴技术，在催化领域的应用潜力巨大，纳米材料已收到深入研究的兴趣在过去几十年。当中的纳米级催化剂报道，贵金属催化剂，如金，银，钯和铂吸引了世界的广泛关注1-3。选择催化反应包括一氧化碳研究者氧化的金，赫克在Pd催化剂的反应，并与铂分解水。尽管有为催化潜力，纳米级金在其适用性由于从中毒，焦化，热降解，和烧结失活限制。已经报道了金，作为贵金属的代表，具有高的选择性和不易于金属浸出，过度氧化和自中毒4。然而，金的催化性能强烈地依赖于颗粒尺寸。春田等人已报告的催化性能与去之间的关系ld的团簇直径，这表明金催化剂的活性最高粒度〜2.7毫微米5。 贵金属的粒径，可以通过在制备方法6-9进行控制;然而，走向广阔的应用的主要障碍仍然聚集而失去活性。为了解决烧结的问题，通常的方法是将固定纳米级颗粒在载体材料上。各种辅助材料已应用于包括多孔二氧化硅10-11，半导体金属氧化物12-13，聚合物14，石墨烯15和碳纳米管16。之间所使用的材料，多孔硅石是一个有吸引力的材料作为支持，因为它是唯一的弱酸性，相对惰性的，热和化学稳定的，并且能以非常明确的内消旋/微孔隙率来制备。多孔结构提供了良好的支持金属颗粒，但也赋予的大小选择衬底通道的金属催化剂。这种选择性是因为与这些多孔材料有关的可调谐性的特别有前途的。通常情况下，金颗粒被发现是在硅胶上表面17-18极其移动和容易地当暴露于高温时形成非常大的（50 + nm）的反应性的颗粒，从而使得难以制备金纳米颗粒在二氧化硅上19。 Mukherjee 等。的单分散金纳米粒子上的介孔二氧化硅的MCM-41由3-氨基丙基-三甲氧基硅烷和3-巯基丙基-三乙氧基硅烷，以及支持的金纳米颗粒报道固定化被认为是用于氢化反应的高活性和无浸出的金被发现在反应20。 下面介孔二氧化硅的表面改性的报告中，我们报道了法制备金嵌入到介孔二氧化硅（GMS）的墙。此外，介孔二氧化硅支持的方法提供了一个可扩展的APproach潜在独立地改变催化剂和多孔环境。由于催化过程是重要的经济意义，带来的好处可能是深远的。开发能力的"绿色"催化剂会对环境产生深远的积极影响和改善重要的工业过程的经济可行性和资源利用效率。

<table><tbody><tr><td>poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)</td><td>Aldrich</td><td>435465-250ML</td><td></td></tr><tr><td>tetraethoxysilane</td><td>TCI</td><td>201-083-8</td><td></td></tr><tr><td>bis[3-(triethoxysilyl)propyl]-tetrasulfide</td><td>GELEST</td><td>SIB1825.0-100GM</td><td></td></tr><tr><td>chloroauric acid</td><td>Aldrich</td><td>520918-1G</td><td></td></tr><tr><td>benzyl alcohol</td><td>Sigma-Aldrich</td><td>305197-1L</td><td></td></tr><tr><td>nitrogen physisorption</td><td>Micromeritics</td><td>Tristar II</td><td></td></tr><tr><td>X-ray diffraction</td><td>Philips</td><td>X&#039;Pert Pro</td><td></td></tr><tr><td>transmission electron microscopy</td><td>Philips</td><td>CM200</td><td></td></tr><tr><td>gas chromatography</td><td>Shimadzu</td><td>GC-2010</td><td></td></tr></tbody></table>

synthesis and catalytic performance of gold intercalated in the walls of mesoporous silica

作为有希望的催化活性纳米反应器，在介孔二氧化硅（GMS）的插层纳米金成功地合成和材料的性能进行了研究。我们使用了一锅溶胶 - 凝胶方法来插层中孔二氧化硅的壁金纳米颗粒。开始与合成，P123用作模板以形成胶束。然后TESPTS用作表面改性剂插层金纳米颗粒。按照此过程，TEOS加入在作为经历聚合过程在酸性环境中的二氧化硅源。热液处理和煅烧后，获得的最终产品。几种技术被用于表征金插孔二氧化硅的孔隙率，形态和结构。结果表明金插后的介孔二氧化硅的稳定的结构。通过苄醇的氧化为基准的反应，所述GMS材料表现出高选择素拉了一和可回收性。

该方法是用来比较在正常（HBEC30KT）血红素合成的水平与癌（HCC4017）肺细胞。 图2示出了血红素合成中的癌细胞（HCC4017）比正常肺细胞（HBEC30KT）的更高的水平。血红素合成的水平，也测量在正常细胞和癌细胞中的线粒体解偶联剂羰氰-3-氯苯（CCCP）的存在。用10微米的CCCP的血红素合成水平测量之前处理细胞24小时。正如所料，血红素合成的水平（ 图2）中的CCCP的在正常和?...

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

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.

合成和金插在介孔二氧化硅的墙壁催化性能

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

synthesis-catalytic-performance-gold-intercalated-walls-mesoporous

Research

JoVE Journal

Chemistry

10.0K 次观看.  Colorado School of Mines. 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.

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

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 ...

科研

化学

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using conventional synthesis techniques. Coupling soft landing with in situ characterization using secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS) enables analysis of well-defined surfaces under clean vacuum conditions. The capabilities of three soft-landing instruments constructed in our laboratory are illustrated for the representative system of surface-bound organometallics prepared by soft landing of mass-selected ruthenium tris(bipyridine) dications, [Ru(bpy)3]2+ (bpy = bipyridine), onto carboxylic acid terminated self-assembled monolayer surfaces on gold (COOH-SAMs). In situ time-of-flight (TOF)-SIMS provides insight into the reactivity of the soft-landed ions. In addition, the kinetics of charge reduction, neutralization and desorption occurring on the COOH-SAM both during and after ion soft landing are studied using in situ Fourier transform ion cyclotron resonance (FT-ICR)-SIMS measurements. In situ IRRAS experiments provide insight into how the structure of organic ligands surrounding metal centers is perturbed through immobilization of organometallic ions on COOH-SAM surfaces by soft landing. Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure of well-defined species supported on surfaces.

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of novel materials. Coupled with analysis by in situ secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS), soft landing provides unprecedented insights into the interactions of well-defined species with surfaces.

在质谱选择离子软着陆准备好定义的表面原位二次离子质谱和红外光谱

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using ...

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.

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

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

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.

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

Here, we present a protocol for the in situ synthesis of gold nanoparticles (AuNPs) within the interlayer space of layered titanate films without the aggregation of AuNPs. No spectral change was observed even after 4 months. The synthesized material has expected applications in catalysis, photo-catalysis, and the development of cost-effective plasmonic devices.

在没有聚集的层状钛酸盐薄膜透明的层间金纳米粒子的原位合成

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

工程学

Preparation of Functional Silica Using a Bioinspired Method

The goal of the protocols described herein is to synthesize bioinspired silica materials, perform enzyme encapsulation therein, and partially or totally purify the same by acid elution. By combining sodium silicate with a polyfunctional bioinspired additive, silica is rapidly formed at ambient conditions upon neutralization. 
The effect of neutralization rate and biomolecule addition point on silica yield are investigated, and biomolecule immobilization efficiency is reported for varying addition point. In contrast to other porous silica synthesis methods, it is shown that the mild conditions required for bioinspired silica synthesis are fully compatible with the encapsulation of delicate biomolecules. Additionally, mild conditions are used across all synthesis and modification steps, making bioinspired silica a promising target for the scale-up and commercialization as both a bare material and active support medium.
The synthesis is shown to be highly sensitive to conditions, i.e., the neutralization rate and final synthesis pH, however tight control over these parameters is demonstrated through the use of auto titration methods, leading to high reproducibility in reaction progression pathway and yield. 
Therefore, bioinspired silica is an excellent active material support choice, showing versatility towards many current applications, not limited to those demonstrated here, and potency in future applications.

Here, we present a protocol to synthesize bioinspired silica materials and immobilize enzymes therein. Silica is synthesized by combining sodium silicate and an amine &#39;additive&#39;, which neutralize at a controlled rate. Material properties and function can be altered either by in situ enzyme immobilization or post-synthetic acid elution of encapsulated additives.

用 Bioinspired 法制备功能性二氧化硅

The goal of the protocols described herein is to synthesize bioinspired silica materials, perform enzyme encapsulation therein, and partially or totally ...

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.

直接溶液还原法快速合成金、钯、铂气凝胶的研究

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

Surface Properties of Synthesized Nanoporous Carbon and Silica Matrices

In this work, we report the synthesis and characterization of ordered nanoporous carbon material (also called ordered mesoporous carbon material [OMC]) with a 4.6 nm pore size, and ordered silica porous matrix, SBA-15, with a 5.3 nm pore size. This work describes the surface properties of nanoporous molecular sieves, their wettability, and the melting behavior of D2O confined in the differently ordered porous materials with similar pore sizes. For this purpose, OMC and SBA-15 with highly ordered nanoporous structures are synthesized via impregnation of the silica matrix by applying a carbon precursor and by the sol-gel method, respectively. The porous structure of investigated systems is characterized by an N2 adsorption-desorption analysis at 77 K. To determine the electrochemical character of the surface of synthesized materials, potentiometric titration measurements are conducted; the obtained results for OMC shows a significant pHpzc shift toward the higher values of pH, relative to SBA-15. This suggests that investigated OMC has surface properties related to oxygen-based functional groups. To describe the surface properties of the materials, the contact angles of liquids penetrating the studied porous beds are also determined. The capillary rise method has confirmed the increased wettability of the silica walls relative to the carbon walls and an influence of the pore roughness on the fluid/wall interactions, which is much more pronounced for silica than for carbon mesopores. We have also studied the melting behavior of D2O confined in OMC and SBA-15 by applying the dielectric method. The results show that the depression of the melting temperature of D2O in the pores of OMC is about 15 K higher relative to the depression of the melting temperature in SBA-15 pores with a comparable 5 nm size. This is caused by the influence of adsorbate/adsorbent interactions of the studied matrices.

Here we report the synthesis and characterization of ordered nanoporous carbon (with a 4.6 nm pore size) and SBA-15 (with a 5.3 nm pore size). The work describes the surface and textural properties of nanoporous molecular sieves, their wettability, and the melting behavior of D2O confined in the materials.

合成纳米碳和二氧化硅矩阵的表面性能

In this work, we report the synthesis and characterization of ordered nanoporous carbon material (also called ordered mesoporous carbon material [OMC]) ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

两栖金纳米粒子的合成与表征

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...

Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry

With this protocol, a well-defined singlesite silica-supported heterogeneous catalyst [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is designed and prepared according to the methodology developed by surface organometallic chemistry (SOMC). In this framework, catalytic cycles can be determined by isolating crucial intermediates. All air-sensitive materials are handled under inert atmosphere (using gloveboxes or a Schlenk line) or high vacuum lines (HVLs, &#60;10-5 mbar). The preparation of SiO2-700 (silica dehydroxylated at 700 &#176;C) and subsequent applications (the grafting of complexes and catalytic runs) requires the use of HVLs and double-Schlenk techniques. Several well-known characterization methods are used, such as Fourier-transform infrared spectroscopy (FTIR), elemental microanalysis, solid-state nuclear magnetic resonance spectroscopy (SSNMR), and state-of-the-art dynamic nuclear polarization surface enhanced NMR spectroscopy (DNP-SENS). FTIR and elemental microanalysis permit scientists to establish the grafting and its stoichiometry. 1H and 13C SSNMR allows the structural determination of the hydrocarbon ligands coordination sphere. DNP SENS is an emerging powerful technique in solid characterization for the detection of poorly sensitive nuclei (15N, in our case). SiO2-700 is treated with about one equivalent of the metal precursor compared to the amount of surface silanol (0.30 mmol&#183;g-1) in pentane at room temperature. Then, volatiles are removed, and the powder samples are dried under dynamic high vacuum to afford the desired materials [(&#8801;Si-O-)Hf(&#951;2&#960;-MeNCH2)(&#951;1-NMe2)(&#951;1-HNMe2)]. After a thermal treatment under high vacuum, the grafted complex is converted into metal imido silica complex [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)]. [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] effectively promotes the metathesis of imines, using the combination of two imine substrates, N-(4-phenylbenzylidene)benzylamine, or N-(4-fluorobenzylidene)-4-fluoroaniline, with N-benzylidenetert-butylamine as substrates. A significantly lower conversion is observed with the blank runs; thus, the presence of the imido group in [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is correlated to the catalytic performance.

A new group IV metal catalyst for imine metathesis is prepared by grafting amine metal complex onto dehydroxylated silica. Surface metal fragments are characterized using FT-IR, elemental microanalysis, and solid-state NMR spectroscopy. Further dynamic nuclear polarization surface enhanced NMR spectroscopy experiments complement the determination of the coordination sphere.

利用表面有机金属化学方法，利用硅支持的催化剂进行Imine金属分析

With this protocol, a well-defined singlesite silica-supported heterogeneous catalyst [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is designed and prepared ...

A Salt-Templated Synthesis Method for Porous Platinum-based Macrobeams and Macrotubes

The synthesis of high surface area porous noble metal nanomaterials generally relies on time consuming coalescence of pre-formed nanoparticles, followed by rinsing and supercritical drying steps, often resulting in mechanically fragile materials. Here, a method to synthesize nanostructured porous platinum-based macrotubes and macrobeams with a square cross section from insoluble salt needle templates is presented. The combination of oppositely charged platinum, palladium, and copper square planar ions results in the rapid formation of insoluble salt needles. Depending on the stoichiometric ratio of metal ions present in the salt-template and the choice of chemical reducing agent, either macrotubes or macrobeams form with a porous nanostructure comprised of either fused nanoparticles or nanofibrils. Elemental composition of the macrotubes and macrobeams, determined with x-ray diffractometry and x-ray photoelectron spectroscopy, is controlled by the stoichiometric ratio of metal ions present in the salt-template. Macrotubes and macrobeams may be pressed into free standing films, and the electrochemically active surface area is determined with electrochemical impedance spectroscopy and cyclic voltammetry. This synthesis method demonstrates a simple, relatively fast approach to achieve high-surface area platinum-based macrotubes and macrobeams with tunable nanostructure and elemental composition that may be pressed into free-standing films with no required binding materials.

A synthesis method to obtain porous platinum-based macrotubes and macrobeams with a square cross section through chemical reduction of insoluble salt-needle templates is presented.

多孔铂基微波和宏管的盐模板合成方法

The synthesis of high surface area porous noble metal nanomaterials generally relies on time consuming coalescence of pre-formed nanoparticles, followed ...