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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.

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.

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.