Synthesis of mesoporous silicas of controlled pore wall thickness and their replication to ordered nanoporous carbons with various pore diameters

A synthesis strategy for the systematic control of the pore wall thickness has been developed for the mesoporous silicas with 2-D hexagonal order using ionic and nonionic surfactant mixtures. The mesoporous silicas have been used as templates for the synthesis of 2-D hexagonally ordered mesoporous carbons with controlled pore diameters. The synthesis strategy and results are useful not only for tailoring the properties of the mesoporous materials but also for extending our insights into the synthesis mechanism.     

高分子担载卟啉及其金属络合物研究进展

本文介绍了高分子担载卟啉及其金属络合物在模拟细胞色素Ｐ－４５０，光学灭菌材料，阴离子载体及光敏化学材料等领域的最新研究进展。     

Synthesis of Metallic Nanoparticles Using Closed‐Shell Structures as Templates

The synthesis and study of metallic nanoparticles are of continued and significant interest, with applications in materials science, catalysis, and medicine. The properties of metallic nanoparticles depend strongly on their particle size, shape, and interparticle distances. It is therefore desirable for the synthesis of metallic nanoparticles to be controlled for specific shapes and sizes. The rapid development in this research area has attracted intense interest from researchers with diverse expertise, and numerous methods towards the synthesis of monodisperse nanoparticles have been reported. In this Focus Review, we provide an overview of recent progress in the development of the template synthesis of metallic nanoparticles using closed‐shell structures, including biological molecules/assemblies and cage molecules.     

水热合成法在分子筛中组装功能材料

采用水热合成法将ZnS、MoO₃和邻苯二甲酸铕组装到ZSM-5分子筛孔道之中,制得了具有纳米尺寸的功能材料,通过XRD、IR、发射光谱和探针分子吸附等手段进行了表征.     

Assembling phenomena of calix[4]hydroquinone nanotube bundles by one-dimensional short hydrogen bonding and displaced pi-pi stacking

Using the computer-aided molecular design approach, we recently reported the synthesis of calix[4]hydroquinone (CHQ) nanotube arrays self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds (H-bonds) and aromatic-aromatic interactions. Here, we assess various calculation methods employed for both the design of the CHQ nanotubes and the study of their assembly process. Our calculations include ab initio and density functional theories and first principles calculations using ultrasoft pseudopotential plane wave methods. The assembly phenomena predicted prior to the synthesis of the nanotubes and details of the refined structure and electronic properties obtained after the experimental characterization of the nanotube crystal are reported. For better characterization of intriguing 1-D short H-bonds and exemplary displaced pi-pi stacks, the X-ray structures have been further refined with samples grown in different solvent conditions. Since X-ray structures do not contain the positions of H atoms, it is necessary to analyze the system using quantum theoretical calculations. The competition between H-bonding and displaced pi-pi stacking in the assembling process has been clarified. The IR spectroscopic features and NMR chemical shifts of 1-D short H-bonds have been investigated both experimentally and theoretically. The dissection of the two most important interaction components leading to self-assembly processes would help design new functional materials and nanomaterials.     

Ordered 2-D and 3-D nanostructured amphiphile self-assembly materials stable in excess solvent

Amphiphile lyotropic liquid crystalline self-assembly materials are being used for a diverse range of applications. Historically, the most studied lyotropic liquid crystalline phase is probably the one-dimensional (1-D) lamellar phase, which has been employed as a model system for biomembranes and for drug delivery applications. In recent years, the structurally more complex 2-D and 3-D ordered lyotropic liquid crystalline phases, of which reversed hexagonal (H(2)) and reversed cubic phases (v(2)) are two prominent examples, have received growing interest. As is the case for the lamellar phase, these phases are frequently stable in excess water, which facilitates the preparation of nanoparticle dispersions and makes them suitable candidates for the encapsulation and controlled release of drugs. Integral membrane protein crystallization media and templates for the synthesis of inorganic nanostructured materials are other applications for 2-D and 3-D amphiphile self-assembly materials. The number of amphiphiles identified as forming nanostructured reversed phases stable in excess solvent is rapidly growing. In this article, different classes of amphiphiles that form reversed phases in excess solvent are reviewed, with an emphasis on linking phase behavior to amphiphile structure. The different amphiphile classes include: ethylene oxide-, monoacylglycerol-, glycolipid-, phosphatidylethanolamine-, and urea-based amphiphiles.     

The chemistry of the p-block elements with thioether, selenoether and telluroether ligands

The synthesis and structures of acyclic and macrocyclic thio-, seleno- and telluro-ether complexes of the metallic and metalloid elements of Groups 13-16 reported since 2000 are described. The diverse structures range from discrete monomers through to infinite 1-, 2- or 3-D polymers. The coordination chemistry in this area is quite different to familiar d-block chemistry and the underlying factors are explored.     

A Review on 1-D Nanomaterials: Scaling-Up with Gas-Phase Synthesis

Nanowire-like materials exhibit distinctive properties comprising optical polarisation, waveguiding, and hydrophobic channelling, amongst many other useful phenomena. Such 1-D derived anisotropy can be further enhanced by arranging many similar nanowires into a coherent matrix, known as an array superstructure. Manufacture of nanowire arrays can be scaled-up considerably through judicious use of gas-phase methods. Historically, the gas-phase approach however has been extensively used for the bulk and rapid synthesis of isotropic 0-D nanomaterials such as carbon black and silica. The primary goal of this review is to document recent developments, applications, and capabilities in gas-phase synthesis methods of nanowire arrays. Secondly, we elucidate the design and use of the gas-phase synthesis approach; and finally, remaining challenges and needs are addressed to advance this field.     

Biogenic synthesis of gold and silver nanoparticles used in environmental applications: A review

Due to their physical, chemical, optical, and mechanical properties, metallic nanoparticles (MNPs) are increasingly being used, with an emphasis on silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). In recent years, green synthesis has gained prominence for exploring the use of naturally available biological sources for the obtention of metallic nanoparticles. Among these, algae and plants stand out due to the presence of polysaccharides, proteins, polyphenols, and vitamins (among others) in their composition, which can act in the reduction and stabilisation of MNPs, and these biogenic materials have been characterised mainly by spectrometric and microscopic techniques. In addition, due to the numerous advantages of nanoparticles (NPs) synthetize from biogenic source, such as their simplicity and cost benefits, they have been used in the development of sensors applied in the determination of contaminants present in environmental samples and in the catalytic reduction of organic and inorganic contaminants. Therefore, this review describes the synthesis, mechanisms, characterization, and environmental analytical applications of NPs obtained by biogenic synthesis as well as the perspectives and challenges of these NPs.     

Plant-Based Synthesis of Gold Nanoparticles and Theranostic Applications: A Review

Bionanotechnology is a branch of science that has revolutionized modern science and technology. Nanomaterials, especially noble metals, have attracted researchers due to their size and application in different branches of sciences that benefit humanity. Metal nanoparticles can be synthesized using green methods, which are good for the environment, economically viable, and facilitate synthesis. Due to their size and form, gold nanoparticles have become significant. Plant materials are of particular interest in the synthesis and manufacture of theranostic gold nanoparticles (NPs), which have been generated using various materials. On the other hand, chemically produced nanoparticles have several drawbacks in terms of cost, toxicity, and effectiveness. A plant-mediated integration of metallic nanoparticles has been developed in the field of nanotechnology to overcome the drawbacks of traditional synthesis, such as physical and synthetic strategies. Nanomaterials′ tunable features make them sophisticated tools in the biomedical platform, especially for developing new diagnostics and therapeutics for malignancy, neurodegenerative, and other chronic disorders. Therefore, this review outlines the theranostic approach, the different plant materials utilized in theranostic applications, and future directions based on current breakthroughs in these fields.     

The roughened silver–palladium cathode for electrocatalytic reductive dechlorination of 2,4-Dichlorophenoxyacetic acid

The roughened silver–palladium (Pd/Ag(r)) electrode was fabricated by a convenient metallic replacement reaction, and its electrocatalytic property towards reductive dechlorination of 2,4-Dichlorophenoxyacetic acid (2,4-D) in basic aqueous solution have been evaluated. Experimental evidence is presented that Pd/Ag(r) exhibited powerful electrocatalytic activity for dechlorination of 2,4-D. In addition, a new dechlorination mechanism of 2,4-D was proposed, in which the formation of adsorbed 2,4-D on Ag is a key step.     

The function of ruthenium oxides in Pt-Ru catalysts for methanol electro-oxidation at low temperatures

The electrocatalytic activities of different binary Pt-Ru(ox) catalysts have been investigated in half-cell experiments by cyclic voltammetry and stationary current–potential measurements. The materials have been prepared using a modification of the Adams method. X-ray analytical methods (X-ray diffraction, XRD, and energy dispersive X-ray spectroscopy, EDX) as well as thermogravimetric analysis (TGA) have been used to characterize the composition and the catalysts' content of the crystalline phases, and their surface areas have been determined by the BET method. It is found that the composition of the catalyst is strongly influenced by the synthesis temperature, which is varied between 400 and 600 °C. In contrast, the particle size of the metallic phases of the catalysts is not significantly affected for synthesis temperatures below 600 °C, as investigated by transmission electron microscopy. Synthesis temperatures of 500 °C favor the formation of crystalline RuO₂ phases, whereas at synthesis temperatures below 500 °C the presence of metallic alloy and of hydrous oxides was derived by the combined XRD and EDX measurements. The stationary current–potential curves show a correlation with the different synthesis temperatures. It can be concluded that both the presence of an alloyed metallic Pt-Ru phase as well as the presence of amorphous hydrated Ru oxides are favorable for the electrocatalytic oxidation of methanol.Dedicated to Prof. Wolf Vielstich on the occasion of his 80th birthday in recognition of his numerous contributions to interfacial electrochemistry     

One-dimensional assemblies of platinum nanoparticles on a graphite surface using nonionic/ionized mixed hemicylindrical micelle templates

One-dimensional (1-D) self-assemblies of Pt nanoparticles on a graphite surface have been synthesized via a template-directed sintering process of individual nanoparticles, using nonionic/cationic mixed hemicylindrical micelle templates of dodecyldimethylamine oxide surfactant at graphite/solution interfaces. The dimension and morphology of Pt nanoparticles can be widely controlled by the concentration of Pt ions equivalent to the mixing ratio of nonionic and cationic species in the surfactant micelle. This approach could be extended to fabricate a wide range of self-assembling metallic nanostructures on surfaces using various nonionic/cationic mixed micelle-like self-assemblies carrying metal ions at interfaces, while providing a fundamental insight into a 1-D self-assembly from individual nanoparticles.     

Breakthrough and future: nanoscale controls of compositions,morphologies, and mesochannel orientations toward advanced mesoporous materials

Currently, ordered mesoporous materials prepared through the self‐assembly of surfactants have attracted growing interests owing to their special properties, including uniform mesopores and a high specific surface area. Here we focus on fine controls of compositions, morphologies, mesochannel orientations which are important factors for design of mesoporous materials with new functionalities. This Review describes our recent progress toward advanced mesoporous materials. Mesoporous materials now include a variety of inorganic‐based materials, for example, transition‐metal oxides, carbons, inorganic‐organic hybrid materials, polymers, and even metals. Mesoporous metals with metallic frameworks can be produced by using surfactant‐based synthesis with electrochemical methods. Owing to their metallic frameworks, mesoporous metals with high electroconductivity and high surface areas hold promise for a wide range of potential applications, such as electronic devices, magnetic recording media, and metal catalysts. Fabrication of mesoporous materials with controllable morphologies is also one of the main subjects in this rapidly developing research field. Mesoporous materials in the form of films, spheres, fibers, and tubes have been obtained by various synthetic processes such as evaporation‐mediated direct templating (EDIT), spray‐dried techniques, and collaboration with hard‐templates such as porous anodic alumina and polymer membranes. Furthermore, we have developed several approaches for orientation controls of 1D mesochannels. The macroscopic‐scale controls of mesochannels are important for innovative applications such as molecular‐scale devices and electrodes with enhanced diffusions of guest species. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 321–339; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900022     

Ultralow-density nanostructured metal foams: combustion synthesis, morphology, and composition

The synthesis of low-density, nanoporous materials has been an active area of study in chemistry and materials science dating back to the initial synthesis of aerogels. These materials, however, are most often limited to metal oxides, e.g., silica and alumina, and organic aerogels, e.g., resorcinol/formaldehyde, or carbon aerogels, produced from the pyrolysis of organic aerogels. The ability to form monolithic metallic nanocellular porous materials is difficult and sometimes elusive using conventional methodology. Here we report a relatively simple method to access unprecedented ultralow-density, nanostructured, monolithic, transition-metal foams, utilizing self-propagating combustion synthesis of novel transition-metal complexes containing high nitrogen energetic ligands. During the investigation of the decomposition behavior of the high-nitrogen transition metal complexes, it was discovered that nanostructured metal monolithic foams were formed in a post flame-front dynamic assembly having remarkably low densities down to 0.011 g cm(-3) and extremely high surface areas as high as 270 m(2) g(-1). We have produced monolithic nanoporous metal foams via this method of iron, cobalt, copper, and silver metals. We expect to be able to apply this to many other metals and to be able to tailor the resulting structure significantly.     

Synthesis and bioanalytical applications of specific-shaped metallic nanostructures: A review

Many successful synthesis routes for producing different shapes of metallic nanostructures, including sphere, rod, cube, and hollow shapes, have been developed in the past few decades. Many applications using these nanostructures have been studied because the outstanding properties of the nanostructures are not exhibited by their bulk-state counterparts. This review paper reports some recent developments in clinical and biosensor applications. The first part focused on the synthesis methods of metallic nanostructures having various shapes along with their optical properties. The second and third part is an introduction of the gold nanoparticle assemblies and arrays, explaining the conjugation methods of metallic nanostructures with biological entities. The final part reviews on the recent bioanalytical applications using various shapes of metallic nanostructures.     

Synthesis and properties of sol-gel submicron silica powders doped with partly oxidized iron particles

Magnetic powders based on metallic iron crystallites encapsulated in submicron-sized spherical silica particles have been obtained and investigated. The metallic iron clusters have been produced by the exploding wire method. The silica shells have been prepared via the modified sol-gel Stöber method and the metallic particles have been entrapped by occlusion during the silica powder formation. The entrapped iron particles are partially oxidized due to the nature of the synthetic methods employed. The obtained hybrid materials have been investigated by electron microscopy, X-ray diffraction, magnetic and ζ-potential techniques. Such materials can be employed in such applications as e.g. magnetically-controlled drug vectors or electromagnetic field-shielding.     

Novel coordination polymers and structural systematics in the hydrothermal M,M' trans-3(-3-pyridyl)acrylic acid system

The bifunctional ligand trans-3-(3-pyridyl)acrylic acid has been utilized to promote the formation of a novel hetero-metallic [Cu3(C8H6NO2)6Nd2(NO3)6] (1) and two homometallic: [Nd(C8H6NO2)3H2O] (2) and [Cu(C8H6NO2)2] x H2O (3) metal organic framework (MOF) materials. The philosophy here is that a mixture of hard (Nd3+) and softer metal cations will show preference for the carboxylic and pyridyl functional groups, respectively. As such, a 3-D topology 1 has emerged as a stable, heterometallic structure. Efforts to explore structural systematics in this system have led to the synthesis of homometallic end members and hence the formation of a 2-D coordination polymer 2, and a 1-D coordination polymer 3. Presented is an analysis of the effect of a second metal centre on coordination environment, overall structure formation, thermal and luminescence properties.     

含杯芳烃聚合物的合成与应用

杯芳烃在主客体化学中是继冠醚和环糊精之后被广泛关注的第三代主体分子,能够选择性地与客体分子或离子形成络合物。近年来,含杯芳烃聚合物逐渐受到人们的重视。结合聚合物稳定性好,易于加工的特性,含杯芳烃聚合物将有望被开发成为新型功能高分子材料。本文详细介绍了含杯芳烃聚合物的合成及其应用。     

Second sphere supramolecular chirality: racemic hybrid H-bonded 2-D molecular networks

Neutral hybrid 2-D networks have been generated using a bis-amidinium capable of chelating M(CN)6(3-) anions via hydrogen bonds: the packing of the achiral 2-D networks leads to channels which are occupied by water molecules forming polymeric H-bonded chains; furthermore, owing to the dihapto mode of H-bonding, the presence of supramolecular chirality of the delta' and lambda' types taking place within the second coordination sphere of the metallic centre has been demonstrated.