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A commercial high-resolution X-ray computed tomography (CT) was utilized for non-destructive analysis of single fibers. The micro-CT apparatus was employed because it is applicable to both colored and colorless fibers. A sample preparation using adhesive sheets was demonstrated, and the method is similar to typical tape-lift sample collection method in crime cases. Different cross-sectional shapes of nylon and polyester single fibers were non-destructively distinguished, and the method is applicable to all types of fibers. Cross-sectional areas, aperture ratios, and volumes of individual fibers were directly and automatically measured using the open-source software. The observed parameters were within a coefficient of variation of 3%. In addition, a mass of a single fragment of a fiber can be estimated when the local density is given.

There has been much interest in developing protein adsorbents using nanostructured particles, which can be engineered porous materials with fine control of the surface and pore structures. A significant challenge in designing porous adsorbents is the high percentage of available binding sites in the pores owing to their large surface areas and interconnected pore networks. In this study, continuing the idea of using porous materials derived from natural polymers toward the goal of sustainable development, porous pectin particles are reported. The template-assisted spray drying method using calcium carbonate (CaCO

A commercial X-ray computed tomography (CT) apparatus using a quasi-monochromatic beam was utilized for density estimations and comparisons of a fragmented single fiber. The validation of quasi-monochromaticity of the X-ray source was investigated by radiograph measurements. For the case of a transmittance higher than 50%, the contribution of Cu Kα characteristic X-rays was dominant. To realize a sufficient statistical quality, an attempt to increase the number of averaged voxels was demonstrated using the neighboring slices of the 3D-CT image. A minimum value of the coefficient of variation (CV) was achieved using multiple images rather than using a single image. The observed values of the inverse of the transmitted X-ray intensity (CT value) of the polymers showed a fairly good relationship with their density. An analytical curve derived from measurements of reference samples of known densities could provide the relative density of an unknown fragmented fiber down to the size of 30 μm in diameter and 35 μm in length. The CV of the estimated density was from 1.5 to 2%, which was estimated from the CV of CT values. Moreover, the correlation of CT values was improved with the linear absorption coefficient than the density. A better performance of discrimination of polymers including fibers might be realized with the difference of linear absorption coefficients for X-rays.

Gold–silica (Au–SiO2) nanohybrids are of great technological importance, and it is crucial to develop facile synthetic protocols to prepare Au–SiO2 nanohybrids with novel structures. Here we report the bioinspired synthesis of pomegranate-like SiO2@Au nanoparticles (P-SiO2@Au NPs) via one-step aqueous synthesis from chloroauric acid and tetraethyl orthosilicate mediated by a basic amino acid, arginine. Effects of chloroauric acid, tetraethyl orthosilicate, and arginine on the morphology and optical property of the products are investigated in detail. The P-SiO2@Au NPs achieve tunable plasmon resonance depending on the amount of chloroauric acid, which affects the size and shape of the P-SiO2@Au NPs. Finite-difference time-domain simulations are performed, revealing that the plasmon peak red-shifts with increasing particle size. Arginine serves as the reducing and capping agents for Au as well as the catalyst for SiO2 formation and also promotes the combination of Au and SiO2. Formation process of the P-SiO2@Au NPs is clarified through time-course analysis. The P-SiO2@Au NPs show good sensitivity for both colloidal and paper-based surface-enhanced Raman scattering measurements. They achieve enhancement factors of 4.3 × 107–8.5 × 107 and a mass detection limit of ca. 1 ng using thiophenol as the model analyte., The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.langmuir.0c00334.

Hexagonal cesium tungsten bronze (Cs0.32WO3) nanoparticles are well known as near-infrared (NIR) shielding materials. However, one of the critical issues for industrial applications involves a photochromic instability, i.e., a blue color change of this material under ultraviolet (UV) irradiation. This color change is attributed to the formation of HxWO3 phase through doping of H+ ions into Cs-deficient sites present at the surface of Cs0.32WO3 nanoparticles. Therefore, a new approach was adopted to prevent the color change by synthesizing a Cs0.32WO3 nanoparticle with less Cs-deficient sites using spray pyrolysis followed by heat treatment and short-time milling. The Cs0.32WO3 nanoparticles of spray pyrolysis route exhibited an improved photochromic stability under UV irradiation compared to those synthesized through a solid-state-reaction route. Detailed analysis using atomic resolution transmission electron microscopy revealed that the Cs0.32WO3 nanoparticles of spray pyrolysis route retain Cs ions up to a depth of less than 1 nm from the surface. This work demonstrates that the less-Cs-deficient Cs0.32WO3 nanoparticles are beneficial to improve the photochromic stability.

Oxygen-carbon-contained CrMnFeCoNi coatings were electrodeposited in an organic solvent of DMF-CH3CN (N,N-dimethylformamide-acetonitrile) containing chlorides of chromium, manganese, iron, cobalt, and nickel, with or without supporting electrolyte lithium perchlorate (LiClO4). The coatings’ composition, structure, hardness, and electrocatalytic properties were examined. The presence of lithium in coatings obtained with LiClO4 showed it unsuitable as a supporting electrolyte in this fabrication process. Without LiClO4, oxygen-carbon-contained CrMnFeCoNi coatings were obtained at constant potentials at −2.0, −2.5, and −3.0 V (vs. SSE) by enhancing the concentrations of the target metal ions in the solution. These coatings were mainly amorphous with nanocrystals, which were comprised of >50 atom% oxygen atoms, >7 atom% carbon atoms, and near equiatomic Cr, Mn, Fe, Co, and Ni, showing a high level of hardness and advanced electrocatalytic activity in the oxygen evolution reaction.

Requirements for nanoparticle processing based on energy and cost-effective technologies have increased in recent years. Flame synthesis is widely used on an industrial scale and is superior to gas...

The metastable state hexagonal-tungsten oxide (h-WO3) has been attracting attention over the past decade because of its high reactivity that arises from the hexagonal channels in its crystal structure. Simplification of the process used to synthesize h-WO3 is an important step to facilitate the industrial applications of this material. In this study, we addressed this challenge by developing a spray pyrolysis process to synthesize highly crystalline h-WO3. The ratio of the monoclinic to the hexagonal phase was controlled by adjusting the segregation time. Single-phase h-WO3 nanorods were synthesized using a carrier gas flow rate of 1 L/min, which was equivalent to a segregation time of 18.4 s. The ability of the h-WO3 nanorods to adsorb nitrogen and carbon dioxide was evaluated to confirm the presence of hexagonal channels in the crystal structure.

Non-destructive observations of cross-sectional shapes of acrylic single fibers using X-ray computed tomography (CT) were performed. A commercial X-ray CT apparatus (Rigaku nano3DX) was employed because of its micrometer-scale spatial resolution and remarkable image contrast for soft matter. We assessed two types of sample support, a paraffin strip and a nylon string, for single fiber samples in terms of easy handling and sample recovery. Fixed individual single fibers were loaded into a narrow polyimide tube in both cases, and the tube ensured that the sample remained in the field of view during the CT measurements. In both cases, the cross-sectional shapes of individual single fibers could be distinguished, with a circular shape for one sample and a triangular shape for the other. However, the support using a nylon string was found to be more suitable for further analysis. The cross-sectional profile of the obtained tomographic image showed a clear difference between polyimide and nylon. The intensity ratio or the image contrast corresponded to that of the local densities. It was also found that the effect of the artifact appeared at around the boundaries of the objects, but the local density could still be utilized for examining individual single fibers.

Metal oxide supports have attracted much attention for improving the performance and durability of polymer electrolyte fuel cells. In this study, niobium-doped tin oxide (NTO) nanoparticles with a network structure were synthesized and Pt catalysts deposited on them using a flame aerosol technology. Because the flame method involves a variety of particle formation processes, which depend on the type of raw material and combustion method used, the effect of these processes on the particle structure of the flame-made Pt/NTO was evaluated. When Pt/NTO nanoparticles were prepared by flame-assisted spray pyrolysis (FASP) using an inorganic raw material (metal chloride) with lower combustion enthalpy, the precursor liquid burned incompletely and Pt aggregation was observed. However, when flame spray pyrolysis (FSP) using a combustible precursor solution was used, the precursor rapidly evaporated in spray flames, and NTO with uniformly dispersed Pt was synthesized through gas-to-particle conversion. The electrochemical surface area and mass activity values of 5.44 wt% Pt-loaded NTO particles prepared by FSP were 48.2 m2 g−1 Pt and 338 mA mg−1 Pt, respectively. Flame aerosol synthesis of supported metal catalysts can be widely used as a dry one-step process that does not involve any complicated post-treatment. The two types of noble metal loading processes revealed in this study provide important insights for determining particle design guidelines for in-situ production of supported metal catalysts in flames.

Highly crystalline and hexagonal single-phase cesium tungsten bronze (Cs0.32WO3) nanoparticles were successfully synthesized by a flame-assisted spray pyrolysis followed by annealing under a reducing gas atmosphere. The resulting Cs0.32WO3 nanoparticles featured a pure hexagonal Cs0.32WO3 phase with a high crystallinity and homogeneous chemical composition. Unlike conventional methods, the proposed process in this paper has several advantages, including a short reaction time and the ability to yield products with high purity and good energy efficiency. Furthermore, the Cs0.32WO3 nanoparticles produced in this research showed a remarkable near-infrared shielding ability with a 97.7% cut-off at 1500 nm.

In this work, Pt nanoparticles were deposited onto the surface of Magneli phase titanium suboxide (TiOx) nanoparticles using a microwave-assisted deposition method. The effect of different concentrations of Pt nanoparticles was investigated to evaluate the strong metal-support interactions (SMSIs) between Pt and TiOx based on their performance for the degradation of organic pollutant molecules. The adsorption and catalytic performance of the as-synthesized Pt/TiOx nanoparticles were evaluated with respect to the degradation of rhodamine B (RhB) molecules without any external energy source. The Pt/TiOx nanoparticles with Pt loading at 10 wt% (10%Pt/TiOx) exhibited a remarkable performance. The XPS, CV, and FTIR analyses confirmed the presence of RhB degradation reactions under dark condition. This remarkable performance of the Pt/TiOx nanoparticles was attributed to the SMSIs between Pt and Ti3+ atoms, which improves their performance compared with Pt/TiO2 nanoparticles, and high density of active sites due to their nanometer size, which results in better performance compared with that of Pt/TiOx submicron particles.

Adsorption performance in the biosorption of tungsten using Escherichia coli cells can be significantly improved by using cell suspensions that have been heat-treated at ⩽100°C. In the case of E. coli cells suspension heated at 100°C, the aqueous tungsten ions concentration rapidly decreased from 0.8mmol/L to practically zero within 1h. This biosorption time is much shorter than that of non-heat treated E. coli cells (7h). Furthermore, the adsorption saturation amount for cells heat-treated at 100°C was significantly increased up to 1.62mmol-W/g-E. coli compared to the unheated E. coli cells case (0.62mmol-W/g-E. coli). Determination of the surface potential and surface structure along with quantitative analyses of free amino acids of heat-treated E. coli cells were also carried out and revealed that heated cells have a high zeta potential and express a higher concentration of amino acids on the cell surface.

Carbon dots (CDs) have attracted great attention because of their unique luminescence properties, chemical inertness, thermal stability, high water solubility, low toxicity, and ease of functionalization. Here, the kinetics of nitrogen-doped CD (N-CD) formation by hydrothermal synthesis were evaluated in an attempt to realize the rapid and efficient production of N-CDs. A series of N-CDs was synthesized using various heating rates, reaction times, reaction temperatures, and precursor concentrations. Characterization of the series of N-CDs indicated that N-CD formation is a first-order reaction with a reaction rate constant of 0.634 min−1. In addition, systematic investigation revealed that synthesis temperature is a more important factor to obtain highly fluorescent N-CDs than reaction time. Citric acid amides are formed by the reaction between citric acid and urea at 130 °C and N-CDs consisting of two or three citric acid amide molecules are formed through dehydration, deammoniation and dehydrogenation of citric acid at 150 °C. By adjusting the operating conditions, N-CDs with a highest quantum yield of 39.7% could be produced at a production rate of 50 g h−1 with a reaction time of 16 min. The N-CDs were then embedded in polyvinyl alcohol (PVA) nanofibers. The luminescence intensity of the N-CD–PVA composite nanofibers was more than twice that of the N-CDs in solution.

The surfaces of carbon nanotubes (CNTs) were covered with thin silica layers through the application of 3-aminopropyltriethoxysilane (APTES) in order to enhance the deposition of precious metal and transition metal oxide nanoparticles. Pt metal particles smaller than 2 nm in diameter could be deposited, using a conventional impregnation method, on CNTs coated with silica layers, whereas Pt particles supported on bare CNT surfaces were approximately 3 nm in diameter. Thus, coating CNTs with thin silica layers enhanced the catalytic activity of the Pt catalysts. In addition, CNTs with thin silica layers could be uniformly covered with transition metal oxide layers (ZrO 2 , Nb 2 O 5 and Ta 2 O 5 ) by hydrolysis of the corresponding metal alkoxides. In contrast, metal oxides were very difficult to deposit on bare CNTs. The thin silica layers produced on the CNTs via the use of APTES evidently function as adsorption sites for precursor metals and metal oxides, as well as nucleation sites for metals and metal oxides, allowing the formation of precious metal-CNT and transition metal oxide-CNT composites.

Rare-earth-doped yttrium aluminum garnet (YAG:RE) phosphors have good photoluminescence (PL) properties and are widely used in light-emitting diodes. However, the RE elements used in these phosphors are expensive and in short supply. It is therefore important to develop phosphors that contain smaller amounts of RE materials. One strategy is to produce nanocomposite phosphors in which a cheaper and more readily available material is used as a matrix for an RE oxide. In this study, we produced a YAG:Ce/SiO2 nanocomposite using a sol–gel method; poly(ethylene glycol) and urea were added to promote micelle formation and agglomeration, respectively. The nanocomposites were characterized using X-ray diffraction, scanning and transmission electron microscopies (TEM), and energy-dispersive X-ray spectroscopy. We determined the concentration of SiO2 that provided maximum PL enhancement, and used geometrical models as well as the characterization results to propose an explanation for this enhancement. Our results showed that an SiO2 concentration of 10 vol% provided a PL intensity 120% that of pure YAG:Ce. TEM analysis showed that SiO2 nanoparticles covered the voids between the single grain boundaries of the YAG:Ce crystals, thereby inhibiting light scattering, resulting in enhanced PL. This method will be useful for large-scale synthesis of low-RE, high-PL phosphors.

Fishbone-typed carbon nanofibers (CNFs) that were formed by methane decomposition over silica-supported Ni catalysts were used as catalytic supports for Pt or Pt–Co alloy nanoparticles. The treatment of CNFs with concentrated HNO 3 led to the formation of porous structures as well as to the introduction of oxygen-containing functional groups. Pt metal particles of a few nanometers in diameter could be stabilized on the CNFs treated with HNO 3 and showed a high tolerance to sintering at high temperatures, whereas Pt metal particles supported on the CNFs without any treatment were seriously aggregated at high temperatures. The porous structures and functional groups in the CNFs worked as anchoring sites for Pt metal nanoparticles. Thus, Pt–Co alloy particles of a few nanometers in diameter could be prepared by using the CNF support since the CNFs inhibited the sintering of the alloy particles during the treatment at high temperatures to allow for alloy formation.

The catalytic performance of Pt metal at the tips of carbon nanotubes (CNT@Pt), which was prepared by ethylene decomposition over Pt/MgO, was compared with that of Pt metal on the outer surface of CNT (Pt/CNT). CNT@Pt showed excellent catalytic performance toward the hydrogenation of α, β-unsaturated aldehydes to unsaturated alcohols, which was similar to that of Pt/CNT and resulted from a strong interaction between Pt metal and the CNT. Pt metal particles at the tips of CNTs showed excellent activity for the selective hydrogenation of α, β-unsaturated aldehydes to unsaturated alcohols similarly to Pt metal particles supported on the outer surface of CNTs.

Pd metal supported on carbon nanotubes (Pd/CNT) for use as a cathode catalyst in polymer electrolyte fuel cells was covered with silica layers a few nanometers thick to improve the durability of the catalyst under severe cathode conditions. The silica-coated Pd/CNT cathode catalyst showed similar activity for the oxygen reduction to Pd/CNT despite coverage of the Pd metal with a silica insulator. In addition, the silica-coated Pd/CNT was highly durable during potential cycling between 0.05 and 1.20 V (vs. reversible hydrogen electrode) in aqueous HClO4 while Pd/CNT suffered serious deactivation under the same conditions. The silica layers in the silica-coated Pd/CNT prevent the diffusion of dissolved Pd species from the Pd metal out of the layers. Therefore, silica-coated Pd/CNT was highly durable under the cathode conditions. Furthermore, coverage of Pd/CNT with silica layers inhibited the two-electron reduction of oxygen to H2O2.

Pt-based alloy catalysts such as carbon black-supported Pt–Co catalysts (Pt–Co/CB) are used in the oxygen reduction reaction in polymer-electrolyte fuel cells (PEFCs) and are generally treated at high temperatures to allow for alloy formation. However, treatment of these catalysts at high temperatures results in serious aggregation of alloy particles. In this study, a Pt–Co/CB catalyst was covered with silica layers to inhibit the aggregation of alloy particles during treatment of the catalyst at high temperature for alloy formation. Coverage of Pt–Co/CB with silica promoted Pt–Co alloy formation with a high alloying degree and a small particle size, whereas the alloying degree of Pt–Co alloys in Pt–Co/CB without silica-coating was low, and these alloy particles were seriously aggregated during treatment at high temperature. These silica-coated Pt–Co/CB catalysts showed high activity and excellent durability for the oxygen reduction reaction.

The effects of deformation temperature on texture and thermoelectric properties of p-type Bi0.5Sb1.5Te3 sintered materials were investigated. The sintered materials were prepared by mechanical alloying and hot-press sintering. The hot-press deformation was performed at 723 K and 823 K by applying mechanical pressure in a graphite die. Then, the materials were extruded in the direction opposite to the direction of applied pressure. X-ray diffraction and electron backscattered diffraction patterns showed that the hexagonal c-plane tended to align along the extruded direction when the samples were deformed at high temperatures. The thermoelectric power factor was increased by high-temperature hot-press deformation because of the low electrical resistivity that originated from the c-plane orientation.

A hot-press deformation study of Bi 0.5 Sb 1.5 Te 3 was undertaken to obtain polycrystals with a preferred textural orientation for use in thermoelectric applications. Source materials were prepared by mechanical alloying (MA) as well as hot pressing (HP) and they were deformed at 673-823 K by applying mechanical pressure in a graphite die. The materials were extruded in a direction opposite to the direction of the applied pressure. X-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analyses indicated that the hexagonal c-planes of the samples that were deformed at high temperatures preferably aligned along the direction of the extrusion. The Hall mobility increased as the deformation temperature increased and it showed a good correlation to the textural orientation.

The preparation of the highly refractive transparent TiO 2 -dispersed microspheres with uniform size was studied. These nanocomposite microspheres were prepared via TiO 2 dispersion in an acrylic monomer and the emulsification by the Shirasu porous glass (SPG) membrane technique. Two kinds of the dispersion methods (bead mill dispersion with fine beads and ultrasonic dispersion) were carried out. The suspension prepared by bead mill included well-dispersed TiO 2 nanoparticles and led to the uniformly sized TiO 2 -dispersed microspheres. It was indicated that the dispersibility of TiO 2 in a monomer was the important factor in this process.

Ethylene decomposition was performed over supported Pt catalysts to fabricate composites of Pt metal nanoparticles and carbon nanotubes (CNTs). All supported Pt catalysts (Pt/carbon black, Pt/CNT, Pt/MgO, Pt/Al2O3 and Pt/SiO2) showed catalytic activity for ethylene decomposition at 973 K to form CNTs. Pt metal particles were found at tips of CNTs. These results indicate that Pt metal particles have catalytic activity for growth of CNTs through hydrocarbon decomposition. A broad range (5–50 nm) of CNT diameters were formed from the use of supported Pt metal catalysts although Pt metal particles in the catalysts before ethylene decomposition were relatively uniform in size (2–5 nm). These results imply that Pt metal particles in the catalysts aggregated during ethylene decomposition at 973 K. Aggregation of Pt metal particles in catalysts during ethylene decomposition could be suppressed by covering catalysts with silica layers that were a few nanometers thick. Silica-coated Pt catalysts showed high activity for ethylene decomposition to form CNTs with uniform diameters (8–10 nm) despite the uniform coverage of Pt metal particles with silica layers.

Gallium nitride (GaN) nanoparticles were successfully produced from nano-sized gallium oxide (Ga 2 O 3 ) particles under a flow of ammonia gas. The gallium oxide nanoparticles were prepared by salt-assisted spray pyrolysis (SASP). Highly crystalline Ga 2 O 3 nanoparticles with an average diameter of approximately 10 nm were obtained at various temperatures when a flux salt (LiCl, 5 mol/l) was added to the precursor solution. The effects of the crystallinity of the Ga 2 O 3 particles and nitridation time on transformation to GaN were characterized using X-ray diffraction and scanning/transmission electron microscopy. Highly crystalline GaN nanoparticles with a mean size of 23.4 nm and a geometric standard deviation of 1.68 nm were obtained when Ga 2 O 3 nanoparticles with relatively low crystallinity were used as the starting material. The resulting GaN nanoparticles showed a photoluminescence peak at 364 nm under UV excitation at 254 nm.

High luminance Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce) nanoparticles were prepared from urea-added nitrate aqueous precursor by flame-assisted spray pyrolysis (FASP). The addition of urea into nitrate precursor plays an important role in YAG:Ce nanoparticle formation and in improving its optical performance. The decomposition and combustion of urea in the flame zone provides additional heat to the particles, which coupled with the evolution of large volumes of gasses, contributes to nanoparticle formation. The as-prepared nanoparticles are hexagonal YAlO 3 , that are nearly spherical, rough on the surface and dense—and they can be converted to YAG:Ce after being annealed at 1200 °C for 4 h. The heat-treated particles are single crystalline, smooth in surface and dense with an average size around 50 nm. The optimum cerium-doping concentration of YAG:Ce nanoparticles is 4.0 at.%, which exhibits quantum efficiency of 45.0%. This quantum efficiency is comparable with that of YAG:Ce nanoparticles produced from other processes. The efficient emission of YAG:Ce nanoparticles also originates from a relatively good distribution of Ce ions incorporated into the host material of YAG as evidenced from the elemental mapping analysis.

Carbon nanotube (CNT)-supported Pt metal (Pt/CNT) was covered with silica layers using hydrolysis of 3-aminopropyl-triethoxysilane (APTES) and/or tetraethoxysilane (TEOS). The hydrolysis of APTES resulted in a uniform coverage of Pt/CNT with silica layers, but the silica layers were very thin. Pt/CNT could be coated with silica layers of a few nanometers thickness by hydrolysis of TEOS, but the thickness was not uniform. In contrast, the successive hydrolysis of APTES and TEOS resulted in a uniform coverage of Pt/CNT with silica layers of a few nanometers thickness. Pt metal particles in silica-coated Pt/CNT adsorbed CO chemically despite uniform coverage of Pt metal particles with silica layers. Therefore, silica-coated Pt/CNT demonstrated high catalytic activity in methane combustion.

We developed TiO2-dispersed nanocomposite polymer films, which have a high concentration of 65 wt. % TiO2, high refractive index of 1.85, and high transmittance of 81.5% (thickness: 5 μm). Finely dispersed TiO2 nanoslurry was obtained by using a bead mill filled with fine beads, where two monomers (either neopentyl glycol dimethacrylate or divinylbenzene) and a single organic solvent (butylacetate) were used as a disperse medium. Up to 20 wt. % TiO2 could be added into a polymer film by the direct dispersion of TiO2 in the monomer. Furthermore, it was possible to incorporate high-concentration TiO2 (above 60 wt. %) in the polymer film by replacing the disperse medium with the monomer after the dispersion of TiO2 in the organic solvent. Visually, the surface of these films was smoother than that of other films prepared by direct dispersion. Further, these films were transparent and had a high refractive index.

Functional nanoparticle-dispersed composite polymer materials were prepared. Metal oxide nanoparticles such as BaTiO3 (primary diameter: 20nm) and three sizes of TiO2 (primary diameter: 7, 15, 20nm) were dispersed into acrylic monomer by means of beads mill filled with fine beads (50μm in diameter), and the nanoparticle-dispersed monomers were polymerized to obtain nanocomposite polymers by the suspension polymerization. The morphology, the nanoparticle dispersibility and the compressive strength of prepared polymer were evaluated. As a result, the TiO2-dispersed acrylic polymer spheres were fairly uniform in size with the diameter of several micrometers, and had relatively high compressive strength of 257MPa. It was also confirmed from the transmission electron microscope that the nanoparticles were well-dispersed in the polymer matrix.

Carbon nanotube (CNT)-supported Pt metal nanoparticles were covered with silica layers by utilizing the successive hydrolysis of 3-aminopropyl-triethoxysilane and tetraethoxysilane on CNTs with Pt hydroxide. The CNT-supported Pt metal particles covered with silica layers (denoted as SiO2/Pt/CNT) were used as the electrocatalysts. SiO2/Pt/CNT electrocatalysts showed a high stability for the repeated potential cycling experiment, whereas Pt/CNT electrocatalysts were deactivated seriously for the experiment because of the growth of Pt metal particles in size. The silica layers in SiO2/Pt/CNT prevent the dissolution of Pt metal particles as well as the migration and agglomeration of Pt metal particles on the supports, which results in the improvement of the stability of Pt/CNT electrocatalysts.

Silica-supported Co catalysts were prepared by using microemulsion. The structure and state of the Co species in the catalysts were characterized by TEM, XRD, Co K-edge XANES/EXAFS, and diffuse reflectance UV−vis spectroscopy. Co species in the catalysts prepared using microemulsion were atomically dispersed as Co2+ with tetrahedral symmetry (CoO4), even after reduction of the catalysts with hydrogen at 773 K, while Co metal particles were supported on the silica surface for the catalysts prepared by a conventional impregnation method. The Co catalysts prepared using microemulsion selectively formed multi-walled carbon nanotubes with a uniform diameter by the decomposition of ethylene at 973 K, whereas silica-supported Co catalysts prepared by the impregnation method formed carbon nanofibers with various diameters. In addition, the Co catalysts prepared using microemulsion formed bundles of single- or double-walled carbon nanotubes by methane decomposition at 1073 K. Contact of the Co catalysts with hydro...

Tablets containing both paracetamol (PM) and cloperastine hydrochloride (CLH) in a combination formulation prepared by standard vertical granulation technology were found to have altered pharmaceutical properties. The hardness and disintegration time of tablets containing both PM and CLH gradually increased during storage, and the cross-screw did not operate smoothly during preparation of the mixed powder. The objective of the present study was to investigate the mechanism of formation of eutectic mixtures consisting of PM and CLH. Binary mixtures of PM and CLH in various proportions were prepared as physical mixtures and analyzed by DSC to study their thermal behavior. Phase diagrams obtained from the endothermic peaks due to melting of physical mixtures of PM and CLH demonstrated the formation of eutectic mixtures with eutectic temperatures of 86.9-110.2 degrees C depending on the ratio of constituents. The formation of the eutectic mixture was studied for a 50:50 mol.% ratio of PM and CLH. PXRD analysis revealed that the eutectic mixture of PM and CLH is structurally different from native PM and CLH. The most probable interaction sites between PM and CLH were demonstrated by DSC analysis of a binary mixture of PM and CLH prepared by melt quenching.

Silica-supported Ni catalysts were prepared by using water-in-oil typed microemulsion. By preparation using the microemulsion, Ni metal particles with diameters < ca. 5 nm were covered uniformly with silica layers with thickness of ca. 10 nm, whereas Ni metal particles were supported on the outer surface of silica by a conventional impregnation method. The Ni metal covered with silica (coat-Ni) showed excellent catalytic performance for the partial oxidation of methane into synthesis gas. Coat-Ni showed a high activity and a long life for the partial oxidation of methane at temperatures above 973 K to form CO and hydrogen, whereas Ni metal catalyst supported on silica was rapidly deactivated for the reaction. Ni K-edge XANES/EXAFS and temperature-programmed reduction for these catalysts showed that Ni metal particles in coat-Ni strongly interacted with silica. The strong interaction of Ni metal particles with silica would improve their catalytic performance for the partial oxidation of methane into synthesis gas.

As negative electrode materials with high capacity and long cycle lives for advanced Li-ion batteries, Si-based alloy films have been prepared on Cu-foil substrate by use of electron beam deposition method or magnetron-sputtering method at room temperature. In this study, nano-structures of the Si-based alloy films have been investigated by conventional and analytical transmission electron microscopy. Experimental results are summarized as follows: (1) Si-based alloy films consist of a number of nano-fibers of 5 nm in diameter. Electron diffraction patterns from the films show halo. Crystallites are seldom found in high resolution images. (2) One-dimensional modulations of the constituents are formed in the range of 3.6 to 11 nm in the films. These nano-structures of the Si-based alloy films could relax the volume expansion of the Si during Li-insertion, causing the longer cycle lives than that of the Si film as the negative electrodes.

Highly concentrated hydrogen and carbon nanofibers were produced through methane decomposition in a temperature range of 973–1123 K. Pd-based alloys containing Ni, Co, Rh, or Fe showed high catalytic activity and long life for methane decomposition at 973 K. In particular, Pd–Co/Al2O3 and Pd–Ni/Al2O3 showed the highest hydrogen yield at reaction temperatures above 973 K among all the catalysts tested. Highly concentrated hydrogen ( > 94 vol% ) was formed by methane decomposition over Pd–Co/Al2O3 at 1123 K. SEM images of catalysts [M/Al2O3 (M = Fe, Co, Ni, and Pd) and Pd–M/Al2O3 (M = Fe, Co, Ni, Cu, Ag, and Rh)] after methane decomposition showed the formation of carbons with fibrous structure. In addition, TEM images of Pd–Co/Al2O3 at the initial stage of reaction showed that Pd–Co alloy particles formed carbons from several facets, whereas Co or Pd metal particles formed carbon nanofibers from one facet. This would be one reason why Pd–Co alloy catalysts showed high activity and long life for methane decomposition at high temperatures.

Amorphous Cr-silicide films are prepared by electron-beam-deposition on a Cu-substrate at room temperature. The microstructures of as-grown films are investigated using transmission and analytical electron microscopy. The morphology of the amorphous films is dendritic. In addition, one-dimensional concentration modulations are observed. The modulated structure is revealed not only by TEM imaging but also by a series of satellite spots at the centre of the diffraction pattern. This concentration modulation is confirmed by analytical electron microscopy.

SiO2 nanotubes could be synthesized by hydrolysis of tetraethyl orthosilicate (TEOS) on the surface of carbon nanofibers (CNF), followed by removal of CNF. In the synthesis of SiO2 nanotubes, CNF acted as templates. The wall thickness and the internal diameter of SiO2 nanotubes were changed by hydrolysis time of TEOS and the diameter of CNF templates, respectively. The catalysts for the hydrolysis of TEOS were functional groups on the surface of CNF. The methane decomposition was carried out over SiO2 nanotubes containing Ni metal particles, so that carbon nanotubes with uniform diameter (ca. 8 nm) were formed at the inside of SiO2 nanotubes. This result strongly indicated that SiO2 nanotubes worked as nanoscale reactors.

A plastic deformation process and ratio study of p-type Bi 0.5 Sb 1.5 Te 3 was performed. The ingots were grown by the Bridgman method. Disks were cut from the ingots and deformed by either cold-pressing or by hot-pressing under pulse current heating. The plastic deformation ratio was controlled from 55 to 90%. The crystal structures of the deformed samples were identified by X-ray diffraction and pole figure analyses. The diffraction patterns indicate that the surfaces and bottoms of the samples were highly oriented in the hexagonal (00-l) plane. Thermoelectric properties change depending on not the plastic deformation ratio but the kind of plastic deformation process. The power factor for hot-press deformed samples exceeded those for the original ingots and cold-press deformed samples. The results suggest that the process of hot-press deformation enhances the thermoelectric properties of p-type Bi 0.5 Sb 1.5 Te 3 .

Microstructures of graphite mechanically milled under a hydrogen gas or an argon gas atmosphere using zirconia balls as well as chromium steel balls were investigated. Using transmission electron microscopes, high-resolution transmission electron microscopy (HREM), selected area electron diffraction (SAD), electron energy loss spectroscopy (EELS) and energy dispersive X-ray analysis (EDS) were carried out to compare the microstructures. Hydrogen concentration reaches up to 7.4 mass% after 80 h milling under a hydrogen gas atmosphere using chromium steel balls and homogeneous distribution of iron nano crystals was observed. No significant difference was observed in microstructures of 80 h milled graphite under the different gas atmosphere using the balls of different materials. This suggests that the significant absorption of hydrogen into the mechanically milled graphite strongly relates to the iron nano crystals included there.