作者对罗格斯大学的Thomas J. Emge博士和Wei Liu博士对小角度X射线衍射和粉末X射线衍射的分析和专业知识表示感谢。此外，作者承认郝王对N 2吸附实验的支持。

Al（OH） 3纳米粒子合成<ol><li>将1.40g氯化铝六水合物溶解在5.822g去离子水中。 </li><li>在磁力搅拌下，将2.778g L-精氨酸加入到氯化铝水溶液中。缓慢添加L-精氨酸，使加入的精氨酸溶解，不会形成大块或块状物;此外，缓慢添加降低局部碱度浓度，并为更可控制的水解提供条件。 </li><li>一旦所有精氨酸溶解到溶液中，在50℃下加热溶液72小时;在这一点上，溶液可能表现为混浊的悬浮液。 </li></ol> 2.用NaCl沉淀Al（OH） 3 <ol><li>准备一个长为49英寸和1.125直径的GPC色谱柱。在连续添加凝胶的步骤中包装凝胶，并允许水流过色谱柱以确保适当的包装，凝胶珠之间的空间最小。包装凝胶至约80％的柱子;凝胶填充量每次都变化，仅影响分离物种的保留时间。 </li><li>使用具有10mL注射器循环的HPLC泵将10mL合成的Al（OH） 3纳米颗粒悬浮液（在步骤1.3中制备）引入柱中。定制 - 使用外径大约为0.125英寸的管道进行注射器回路，并校准长度以输送10 mL注射样品。 </li><li> 以与dRI峰位置相关的间隔收集柱洗脱。将GPC输出连接到差分折射率（dRI）检测器的输入。 注意:分离的物质从GPC出来时，它们作为峰值出现在dRI检测器上，然后收集在125 mL瓶中。 GPC色谱柱产生两个分辨良好的峰，两个峰都被收集并用尺寸排阻色谱（SEC）和元素分析（EA）进行分析，以从铝中鉴别精氨酸资本投资者入境计划。收集的总体积将取决于GPC柱的尺寸，所用包装材料的总量以及用于洗脱柱的去离子水的流速。 <ol><li>以0.2 mL / min流速在100 min内收集大部分1号峰。 </li><li>一旦峰值出现在GPC色谱柱的RI检测器上，则以30分钟间隔收集洗脱液。 注意:改变间隔范围会改变所得纯化峰1材料的浓度和纯度。首先收集峰的小间隔是最好的，以确定哪一部分含有特定色谱柱的峰1种类的最高浓度和纯度。 </li></ol></li><li>准备1重量％的NaCl。 </li><li>将制备的NaCl溶液滴加到10mL纯化的Al（OH） 3纳米颗粒中;使用NaCl沉淀制备的材料不用于进一步的实验。 </li></ol> 3.制备Al-MCM-41 <ol><li> AC在真空烘箱中在120℃下真空吸收约1.0g MCM-41 3小时。 </li><li>通过将9.6926g的AlCl 3 ·6H 2 O与40.3074g去离子水相结合来制备50.0g氯化铝溶液。 </li><li>加入0.7g活化的MCM-41至50.0g氯化铝溶液（步骤3.2中制备）。 </li><li>允许足够的混合时间（1小时）以确保在整个MCM-41通道中扩散的AlCl 3的均匀性。 </li><li>在磁力搅拌下，将L-精氨酸加入到异相混合物中，使Arg / Al摩尔比为2.75。与步骤1.2类似，缓慢加入精氨酸，以使瞬时形成的絮凝物在继续添加之前重新溶解并减少精氨酸的聚集。 </li><li>一旦均匀，将混合物在50℃加热72小时。 </li><li>使用布氏漏斗在真空下过滤获得的异质溶液，并配备定性90 mm滤纸圈（或任何其他适当的滤纸）。 </li><li>用过量的去离子水洗涤过滤的白色粉末，以确保从生产的Al-MCM-41材料中除去未反应的氯化铝，精氨酸或水溶性副产物。 </li></ol>

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作者没有什么可以披露的。

氯化铝水溶液的制备需要使用氯化铝的结晶六水合物盐。尽管也可以使用无水形式，但是由于其显着的吸湿性能而不是优选的，这使得难以与铝的浓度一起使用并控制其浓度。值得注意的是，氯化铝溶液在制备后几天内应该使用，因为随着时间的推移，[Al（H 2 O） 6 ] 3+ aqua酸会水解产生不希望的副产物，从而最终降低最终的总产率和纯度产品。这里描述的合成方法用一定?...

由氢氧化铝制成的材料是用于各种工业应用的有希望的候选者，包括催化剂，药物，水处理和化妆品。 1，2，3，4 在升高的温度下，氢氧化铝在分解过程中吸收大量的热量，从而产生氧化铝（Al 2 O 3 ），使其成为有用的阻燃剂。已经使用计算和实验技术研究了四种已知的氢氧化铝多晶型物（ 即 ，三水铝矿，三羟铝石，北氨纶和石灰石），以提高我们对其形成和结构的理解。纳米尺度颗粒的制备是特别有意义的，因为它们具有显示量子效应和性质不同于其的性能的潜力大批量同行在各种条件7,8,9,10,11,12,13,14中容易制备尺寸为100nm量级的纳米微粒。 克服与进一步降低粒径相关的固有挑战是困难的;因此，只有少数情况下存在纳米晶粒尺寸在50nm左右的尺寸。据我们所知，没有关于小于50nm的纳米晶粒颗粒的报道。部分原因在于纳米粒子由于静电不稳定而倾向于聚集并且在胶体颗粒之间形成氢键的可能性很高，特别是在极性质子溶剂中。我们的目的是通过使用专门安全的成分和前体来合成小的Al（OH） 3纳米颗粒。在目前的工作中，通过掺入氨基酸（ 即 L-精氨酸）作为缓冲剂和稳定剂来抑制含水颗粒聚集。此外，据报道，含胍胍的精氨酸可防止氢氧化铝颗粒生长和聚集，得到平均粒径为10-30nm的水性胶态悬浮液。这里提出，精氨酸的两性和两性离子性质缓解了在轻度水解过程中氢氧化铝纳米颗粒的表面电荷，从而使颗粒生长超过30nm。虽然精氨酸不能够将粒径降低到10nm以下，但是通过利用"笼"限制效应在MCM-41的介孔中。 Al-MCM-41复合材料的表征显示了介孔二氧化硅中的超细氢氧化铝纳米颗粒，其平均孔径为2.7nm。

<table border="0" cellpadding="0" cellspacing="0" width="650">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">aluminum chloride hexahydrate</td>
			<td style="width:103px;">Alfa Aesar</td>
			<td align="right" style="width:119px;">12297</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">L-arginine</td>
			<td style="width:103px;">BioKyowa</td>
			<td style="width:119px;">N/A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">aluminum hydroxide</td>
			<td style="width:103px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">239186</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Bio-Gel P-4 Gel</td>
			<td style="width:103px;">Bio-Rad</td>
			<td style="width:119px;">150-4128</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:261px;">Mesoporous siica (MCM-41 type)</td>
			<td style="width:103px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">643645</td>
			<td></td>
		</tr>
	</tbody>
</table>

facile preparation of ultrafine aluminum hydroxide particles with or without mesoporous mcm-41 in ambient environments

通过用铝精氨酸[Al（H 2 O） 6 ] 3+与L-精氨酸滴定至pH4.6，合成了纳米半纤维素水悬浮液。由于已知水合铝盐生产具有宽范围尺寸分布的各种各样的产品，各种最先进的仪器（ 即 27 Al / 1 H NMR，FTIR，ICP-OES ，TEM-EDX，XPS，XRD和BET）用于表征合成产物和副产物的鉴定。使用凝胶渗透色谱（GPC）柱技术分离由纳米颗粒（10-30nm）组成的产物。傅里叶变换红外（FTIR）光谱和粉末X射线衍射（PXRD）鉴定了纯化物质为氢氧化铝的三水铝矿多晶型物。无机盐（ 例如 NaCl）的添加引起悬浮液的静电去稳定，从而使纳米颗粒凝聚ld Al（OH） 3沉淀物，粒径大。通过利用这里描述的新型合成方法，将Al（OH） 3部分负载在MCM-41的高度有序的介孔骨架内，平均孔尺寸为2.7nm，产生具有八面体和四面体Al（O h / T d = 1.4）。使用能量色散X射线光谱法（EDX）测量的总Al含量为11％w / w，Si / Al摩尔比为2.9。大量EDX与表面X射线光电子能谱（XPS）元素分析的比较提供了铝硅酸盐材料中Al分布的了解。此外，与体积（2.9）相比，在外表面（3.6）上观察到更高的Si / Al比。 O / Al比的近似分别表明核心和外表面附近的Al（O） 3和Al（O） 4基团的浓度分别更高。新近开发的Al-MCM-41合成产物同时保持有序二氧化硅骨架的完整性，并且可用于其中水合或无水Al 2 O 3纳米颗粒是有利的应用。

纳米网合成通过用L-精氨酸将AlCl 3 ·6H 2 O（14重量％）滴定至最终的Arg / Al摩尔比为2.75来制备纳米锭。通过SEC来监测纳米晶粒颗粒的合成， SEC是一种广泛用于部分水解的氯化铝溶液的分析技术，能够鉴别任意指定为峰1,2,3,4和5的五个结构域。在这里，我们报道，粒径为10-30nm的纳米晶粒是在典型SEC分析...

Watch this Scientific Journal Video about Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments at JoVE.com

Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

通过在MCM-41的介孔通道内进行笼式效应限制，通过[L-（H 2 O）] 3+与L-精氨酸的对照滴定制备超细氢氧化铝纳米颗粒悬浮液。

在环境环境中制备具有或不具有介孔MCM-41的超细氢氧化铝颗粒

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis ...

facile-preparation-ultrafine-aluminum-hydroxide-particles-with-or

Research

JoVE Journal

Chemistry

10.8K 次观看.  Colgate-Palmolive Company. 通过在MCM-41的介孔通道内进行笼式效应限制，通过[L-（H 2 O）] 3+与L-精氨酸的对照滴定制备超细氢氧化铝纳米颗粒悬浮液。 

视频: Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions

Convenient methods for the rapid, parallel synthesis of diversely functionalized nanoparticles will enable discovery of novel formulations for drug delivery, biological imaging, and supported catalysis. In this report, we demonstrate parallel synthesis of brush-arm star polymer (BASP) nanoparticles by the &#34;brush-first&#34; method. In this method, a norbornene-terminated poly(ethylene glycol) (PEG) macromonomer (PEG-MM) is first polymerized via ring-opening metathesis polymerization (ROMP) to generate a living brush macroinitiator. Aliquots of this initiator stock solution are added to vials that contain varied amounts of a photodegradable bis-norbornene crosslinker. Exposure to crosslinker initiates a series of kinetically-controlled brush+brush and star+star coupling reactions that ultimately yields BASPs with cores comprised of the crosslinker and coronas comprised of PEG. The final BASP size depends on the amount of crosslinker added. We carry out the synthesis of three BASPs on the benchtop with no special precautions to remove air and moisture. The samples are characterized by gel permeation chromatography (GPC); results agreed closely with our previous report that utilized inert (glovebox) conditions. Key practical features, advantages, and potential disadvantages of the brush-first method are discussed.

Poly(ethylene glycol) (PEG) brush-arm star polymers (BASPs) with narrow mass distributions and tunable nanoscopic sizes are synthesized in via ring opening metathesis polymerization (ROMP) of a PEG-norbornene macromonomer followed by transfer of portions of the resulting living brush initiator to vials containing varied amounts of a rigid, photo-cleavable bis-norbornene crosslinker.

颗粒无箱:可光降解的PEG星形聚合物在环境条件刷第一个合成

Convenient methods for the rapid, parallel synthesis of diversely functionalized nanoparticles will enable discovery of novel formulations for drug ...

科研

化学

Activating Molecules, Ions, and Solid Particles with Acoustic Cavitation

The chemical and physical effects of ultrasound arise not from a direct interaction of molecules with sound waves, but rather from the acoustic cavitation: the nucleation, growth, and implosive collapse of microbubbles in liquids submitted to power ultrasound. The violent implosion of bubbles leads to the formation of chemically reactive species and to the emission of light, named sonoluminescence. In this manuscript, we describe the techniques allowing study of extreme intrabubble conditions and chemical reactivity of acoustic cavitation in solutions. The analysis of sonoluminescence spectra of water sparged with noble gases provides evidence for nonequilibrium plasma formation. The photons and the "hot" particles generated by cavitation bubbles enable to excite the non-volatile species in solutions increasing their chemical reactivity. For example the mechanism of ultrabright sonoluminescence of uranyl ions in acidic solutions varies with uranium concentration: sonophotoluminescence dominates in diluted solutions, and collisional excitation contributes at higher uranium concentration. Secondary sonochemical products may arise from chemically active species that are formed inside the bubble, but then diffuse into the liquid phase and react with solution precursors to form a variety of products. For instance, the sonochemical reduction of Pt(IV) in pure water provides an innovative synthetic route for monodispersed nanoparticles of metallic platinum without any templates or capping agents. Many studies reveal the advantages of ultrasound to activate the divided solids. In general, the mechanical effects of ultrasound strongly contribute in heterogeneous systems in addition to chemical effects. In particular, the sonolysis of PuO2 powder in pure water yields stable colloids of plutonium due to both effects.

Acoustic cavitation in liquids submitted to power ultrasound creates transient extreme conditions inside the collapsing bubbles, which are the origin of unusual chemical reactivity and light emission, known as sonoluminescence. In the presence of noble gases, nonequilibrium plasma is formed. The "hot" particles and the photons generated by collapsing bubbles are able to excite species in solution.

活化分子，离子和固体颗粒与声空化

The chemical and physical effects of ultrasound arise not from a direct interaction of molecules with sound waves, but rather from the acoustic ...

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.

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 ...

Facile and Efficient Preparation of Tri-component Fluorescent Glycopolymers via RAFT-controlled Polymerization

Synthetic glycopolymers are instrumental and versatile tools used in various biochemical and biomedical research fields. An example of a facile and efficient synthesis of well-controlled fluorescent statistical glycopolymers using reversible addition-fragmentation chain-transfer (RAFT)-based polymerization is demonstrated. The synthesis starts with the preparation of &#946;-galactose-containing glycomonomer 2-lactobionamidoethyl methacrylamide obtained by reaction of lactobionolactone and N-(2-aminoethyl) methacrylamide (AEMA). 2-Gluconamidoethyl methacrylamide (GAEMA) is used as a structural analog lacking a terminal &#946;-galactoside. The following RAFT-mediated copolymerization reaction involves three different monomers: N-(2-hydroxyethyl) acrylamide as spacer, AEMA as target for further fluorescence labeling, and the glycomonomers. Tolerant of aqueous systems, the RAFT agent used in the reaction is (4-cyanopentanoic acid)-4-dithiobenzoate. Low dispersities (&#8804;1.32), predictable copolymer compositions, and high reproducibility of the polymerizations were observed among the products. Fluorescent polymers are obtained by modifying the glycopolymers with carboxyfluorescein succinimidyl ester targeting the primary amine functional groups on AEMA. Lectin-binding specificities of the resulting glycopolymers are verified by testing with corresponding agarose beads coated with specific glycoepitope recognizing lectins. Because of the ease of the synthesis, the tight control of the product compositions and the good reproducibility of the reaction, this protocol can be translated towards preparation of other RAFT-based glycopolymers with specific structures and compositions, as desired.

An efficient, three-step synthesis of RAFT-based fluorescent glycopolymers, consisting of glycomonomer preparation, copolymerization, and post-modification, is demonstrated. This protocol can be used to prepare RAFT-based statistical glycopolymers with desired structures.

通过RAFT控制聚合轻便和高效制备三组分荧光Glycopolymers

Synthetic glycopolymers are instrumental and versatile tools used in various biochemical and biomedical research fields. An example of a facile and ...

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Functions of clusters in nano or sub-nano scale significantly depend on not only kinds of their components but also arrangements, or symmetry, of their components. Therefore, the arrangements in the clusters have been precisely characterized, especially for metal complexes. Contrary to this, characterizations of molecular arrangements in supramolecular clusters composed of organic molecules are limited to a few cases. This is because construction of the supramolecular clusters, especially obtaining a series of the supramolecular clusters, is difficult due to low stability of non-covalent bonds compare to covalent bonds. From this viewpoint, utilization of organic salts is one of the most useful strategies. A series of the supramolecules could be constructed by combinations of a specific organic molecule with various counter ions. Especially, primary ammonium carboxylates are suitable as typical examples of supramolecules because various kinds of carboxylic acids and primary amines are commercially available, and it is easy to change their combinations. Previously, it was demonstrated that primary ammonium triphenylacetates using various kinds of primary amines specifically construct supramolecular clusters, which are composed of four ammoniums and four triphenylacetates assembled by charge-assisted hydrogen bonds, in crystals obtained from non-polar solvents. This study demonstrates an application of the specific construction of the supramolecular clusters as a strategy to conduct systematical symmetric study for clarification of correlations between molecular arrangements in supramolecules and kinds and numbers of their components. In the same way with binary salts composed of triphenylacetates and one kind of primary ammoniums, ternary organic salts composed of triphenylacetates and two kinds of ammoniums construct the supramolecular clusters, affording a series of the supramolecular clusters with various kinds and numbers of the components.

This article describes construction of a series of hydrogen-bonding supramolecular clusters in crystals using primary ammonium triphenylacetates, which are recrystallized from non-polar solvents. This selective construction of the supramolecular clusters leads to effective systematical symmetric studies about a correlation between the supramolecular clusters and their components.

建筑和超分子集群与二元或三元铵Triphenylacetates一系列的体制性对称研究

Functions of clusters in nano or sub-nano scale significantly depend on not only kinds of their components but also arrangements, or symmetry, of their ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

内部自组装脂质颗粒的简易制备碳纳米管稳定

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Facile Preparation of 4-Substituted Quinazoline Derivatives

Reported in this paper is a very simple method for direct preparation of 4-substituted quinazoline derivatives from a reaction between substituted 2-aminobenzophenones and thiourea in the presence of dimethyl sulfoxide (DMSO). This is a unique complementary reaction system in which thiourea undergoes thermal decomposition to form carbodiimide and hydrogen sulfide, where the former reacts with 2-aminobenzophenone to form 4-phenylquinazolin-2(1H)-imine intermediate, whilst hydrogen sulfide reacts with DMSO to give methanethiol or other sulfur-containing molecule which then functions as a complementary reducing agent to reduce 4-phenylquinazolin-2(1H)-imine intermediate into 4-phenyl-1,2-dihydroquinazolin-2-amine. Subsequently, the elimination of ammonia from 4-phenyl-1,2-dihydroquinazolin-2-amine affords substituted quinazoline derivative. This reaction usually gives quinazoline derivative as a single product arising from 2-aminobenzophenone as monitored by GC/MS analysis, along with small amount of sulfur-containing molecules such as dimethyl disulfide, dimethyl trisulfide, etc. The reaction usually completes in 4-6 hr at 160 &#186;C in small scale but may last over 24 hr when carried out in large scale. The reaction product can be easily purified by means of washing off DMSO with water followed by column chromatography or thin layer chromatography.

A protocol for facile preparation of 4-substituted quinazoline derivatives from 2-aminobenzophenones, thiourea and dimethyl sulfoxide is presented.

的4-取代喹唑啉衍生物简便制备

Reported in this paper is a very simple method for direct preparation of 4-substituted quinazoline derivatives from a reaction between substituted ...

Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass spectrometer, it is necessary to characterize and understand the physical principles of the source. Most commercial ambient ionization sources utilize jets of nitrogen, helium, or atmospheric air to facilitate the ionization of the analyte. As a consequence, schlieren photography can be used to visualize the gas streams by exploiting the differences in refractive index between the streams and ambient air for visualization in real time. The basic setup requires a camera, mirror, flashlight, and razor blade. When properly configured, a real time image of the source is observed by watching its reflection. This allows for insight into the mechanism of action in the source, and pathways to its optimization can be elucidated. Light is shed on an otherwise invisible situation.

This paper presents a protocol for the visualization of gaseous streams of an ambient ionization source using schlieren photography and mass spectrometry.

环境质谱可视化纹影摄影的使用

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass ...

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

使用Photoredox催化剂蠕虫状胶束的简便合成可见光介导的分散聚合

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high atomic and step economy. However, this functionality-directed cross-coupling reaction has not been developed, as there are still limited directing groups in practical use. In particular, a stoichiometric amount of oxidant is usually required, producing a large amount of waste. Due to our interest in novel 1,3-butadiene synthesis, we describe the ruthenium-catalyzed olefination of electron-deficient alkenes using allyl acetate and without external oxidant. The reaction of 2-phenyl acrylamide and allyl acetate was chosen as a model reaction, and the desired diene product was obtained in 80% isolated yield with good stereoselectivity (Z,E/Z,Z = 88:12) under optimal conditions: [Ru(p-cymene) Cl2]2 (3 mol %) and AgSbF6 (20 mol %) in DCE at 110 &#186;C for 16 h. With the optimized catalytic conditions in hand, representative &#945;- and/or &#946;-substituted acrylamides were investigated, and all reacted smoothly, regardless of aliphatic or aromatic groups. Also, differently N-substituted acrylamides have proven to be good substrates. Moreover, we examined the reactivity of different allyl derivatives, suggesting that the chelation of acetate oxygen to the metal is crucial for the catalytic process. Deuterium-labeled experiments were also conducted to investigate the reaction mechanism. Only Z-selective H/D exchanges on acrylamide were observed, indicating a reversible cyclometalation event. In addition, a kinetic isotope effect (KIE) of 3.2 was observed in the intermolecular isotopic study, suggesting that the olefinic C-H metalation step is probably involved in the rate-determining step.

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

The ruthenium-catalyzed olefination of electron-deficient alkenes with allyl acetate is described here. By using aminocarbonyl as a directing group, this external oxidant-free protocol has high efficiency and good stereo- and regioselectivity, opening a novel synthetic route to (Z,E)-butadiene skeletons.

（2<em&gt;ž</em&gt;，4<em&gt;电子</em&gt;） - 通过电子缺陷烯烃与烯丙基乙酸酯的烯化反应制备二烯酰胺

Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high ...