Electrochemically active ceramic anodes for next-generation solid oxide fuel cells (SOFCs) were studied by controlling the anode structure at the submicro-scale. Specifically, the effect of highly porous metal-ceramic structures on electrochemical properties such as power density and conversion efficiency at an intermediate temperature was investigated. Moreover, the structural control technology of active fuel electrodes for direct hydrocarbon SOFCs was discussed. In addition, high-temperature steam solid oxide electrolysis cells (SOECs) with highly porous fuel electrodes have been developed for advanced ceramic reactors.

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When a focused laser beam is irradiated onto a target, electrons and cations are emitted from the target to form a plume (plasma). This phenomenon is referred to as laser ablation (LA). The thin film deposition method using laser ablation is referred to as pulsed laser deposition (PLD). Recombination of electrons and cations usually occurs in the plume before they arrive at a substrate to form a thin film. However, previous reports show that applying a magnetic field to the plume suppresses recombination and enhances electron-impact excitation. The flux of electrons and cations can therefore be controlled by an external magnetic field during PLD. Charged cations can separate from neutral particles or heavy clusters such as droplets. This principle has been used to obtain droplet-free thin films. Applying a magnetic field to the plume also causes ohmic heating and suppression of adiabatic expansion. The electron temperature in a plume with magnetic field application is therefore higher than that in a plume without magnetic field application. This principle has been used to lower crystallization temperatures, improve crystallinity, and enhance thin film properties. Because application of a magnetic field suppresses recombination and enhances electron-impact excitation, several cations exist in the plume. These then rush to the substrates. This principle produces changes the growth mode, which in turn brings about changes in the thin film morphology. Furthermore, this principle leads to phase separation control. The impingement of cations reportedly brings about lowering of the activation energy for diffusion, which leads to phase separation by spinodal decomposition. A thin film with a spontaneous superlattice structure forms when compositional wave propagation occurs in one direction, but when a cross-linked microstructure is obtained the compositional wave direction of propagation is random. This review presents the influence of application of a magnetic field during deposition.

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Calcium hexaboride (CaB₆) nanoparticles were prepared via low temperature magnesiothermic reduction of CaO and B₂O₃ in molten NaCl, KCl or CaCl₂. The effects of salt type, Mg amount, and firing temperature and time on the reaction extents were examined, and the responsible reaction mechanisms were discussed. Under an identical firing condition, CaCl₂ facilitated the overall synthesis more effectively than the other two salts. In the case of using 20 mol % excessive Mg, phase-pure CaB₆ nanoparticles of ∼50 nm were formed in CaCl₂ after 6 h at 800°C. The “dissolution-precipitation” mechanism is believed to be responsible for the molten salt synthesis of high quality nanosized CaB₆ particles at such a low temperature.

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The β-NaGaO₂ thin film is a precursor film for the fabrication of a β-CuGaO₂ thin film by ion exchange, which is expected to be applicable to a thin film solar cell. The β-NaGaO₂ thin films were fabricated by electron beam evaporation, and they showed substrate dependence of the crystal orientation, which is in contrast to the recently reported β-NaGaO₂ films obtained by sputtering that exhibited no substrate dependence. The difference observed for evaporation and sputtering was discussed based on the kinetic energy of the particles impinging on the substrate during the deposition. An appropriate orientation of the β-NaGaO₂ film for ion exchange was discussed in terms of the in-plane shrinkage generated during the ion exchange from β-NaGaO₂ to β-CuGaO₂.

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Supercontinuum (SC) generation in tellurite hybrid microstructured optical fibers (HMOFs) whose refractive index difference between core and cladding materials was as large as 0.49 was demonstrated for the first time. The fiber was successfully fabricated and its chromatic dispersion was tailored to be near-zero and flattened with three zero-dispersion wavelengths at 1270, 1973 and 3627 nm. A broad SC generation was experimentally demonstrated with 5-dB spectral flatness over a 1060-nm spectral bandwidth by using a 20-cm-long section of the fabricated tellurite HMOF.

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Porcelain ceramic tiles are low-temperature prepared by introducing multiple fluxes. The multiple flux compositions are potash feldspar-sodium feldspar-lithium porcelain stone- calcite four flux system. Effects of calcite contents on the microstructure, sintering and mechanical properties of the samples are studied in a fast firing process. The sintering behaviors of the samples are evaluated by linear shrinkage, water absorption and bulk density. The fired samples are characterized by X-ray diffraction, scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy and bending strength measurements. Well densification of the porcelain ceramic tiles is obtained at a low temperature 1130–1150°C. The sample prepared with 11% calcite exhibits higher shrinkage and bulk density, lower water absorption at a temperature of 1130°C. Higher bending strength at a composition containing at 11% calcite is due to appropriate densification and high anorthite, quartz and mullite crystallinity.

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Rose flower-like Bi₂WO₆ hierarchical architectures with average diameter of 7 µm were synthesized via a hydrothermal route. The as-synthesized Bi₂WO₆ hierarchical architectures were decorated with Au nanoparticles (20–110 nm in size) by a photocatalytic reduction method. The prepared samples were systematically investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, electrochemical impedance spectroscopy and photocurrent response. The photocatalytic performance of the samples was evaluated by the degradation of RhB in aqueous solution under simulated sunlight irradiation. It is observed that Au–Bi₂WO₆ composite exhibits a photocatalytic activity much higher (about 2.7 times higher) than that of bare Bi₂WO₆. The enhanced photocatalytic activity of Au–Bi₂WO₆ can be attributed to the enhanced separation of photogenerated electron–hole pairs due to the electron migration from Bi₂WO₆ hierarchical architectures to Au nanoparticles. As a result, more electrons and holes are able to participate in the photocatalytic reactions. The underlying photocatalytic mechanism was discussed.

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The fixing of electrophoretically deposited natural zeolite particles on a metal substrate by “geopolymer reaction,” i.e. the polymerization of silicate monomers in a solution to form a polymer phase that can bind particles onto solid materials, was investigated. Finely ground natural zeolite (clinoptilolite) particles were dispersed in ethanol, and deposited on a stainless-steel electrode by electrophoretic deposition (EPD) with silica sol particles and polyvinylpyrrolidone (PVP) as binder materials. The deposit was then fixed to the electrode by curing in an alkali silicate aqueous solution containing Na₂SiO₃ and NaOH at 40°C for 24 h. The addition of the mixed binder of silica sol and PVP to the suspension used for the EPD was effective for the fixing treatment. After the fixing treatment, the durability of the zeolite deposit in stirred water was largely enhanced. It was also found that fixed deposits treated in solutions containing a smaller amount of Na₂SiO₃ showed better durability. Fixed deposits, containing the starting zeolite phase, moreover, showed the adsorption property of Pb²⁺ ions in the aqueous solution.

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A facile surface modification technique for imposing antifouling properties on ceramic microfiltration (MF) membranes was developed based on the chemical conjugation of organosilane molecules on ceramics. The ceramic MF membranes (pore size: approximately 0.1 µm) were fabricated using conventional dip coating in an alumina slurry with nano-sized particles. The membranes were subsequently subjected to organosilane grafting with different molar concentrations (25, 50, and 100 mM). The physicochemical analysis of the organosilane-grafted membranes revealed a small decrease in pore size/roughness, which resulted from the new formation of organosilane multilayers (i.e., pore-filling effect). The pure water permeability was also diminished to some extent while exhibiting minimal influence on the permeation flux. Because of the electrostatic repulsion force between the surface-modified MF membranes and the model foulants, serious foulant adsorption followed by flux decline was significantly alleviated. In particular, the lowest organosilane concentration (25 mM) showed the greatest flux performance. This was mostly attributed to the reduced effect of pore-size restriction and electrostatic repulsion forces. We therefore achieved the optimum organosilane-grafting conditions for ceramic MF membranes, which not only minimized the alteration of surface morphology/pore size and hydraulic permeability but also remarkably improved the antifouling properties.

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Hydrophobic silica xerogels containing trimethylsilyl (TMS) and dimethylsilyl (DMS) organic hydrophobic functional groups were synthesized using waterglass as the starting material. Five types of hydrophobic silica xerogels with varying surface coverages of the TMS and DMS groups were synthesized by changing the molecular structure of siloxane, which was used to introduce the hydrophobic moieties into the hydrogel and to investigate the resultant surface structures and thermal characteristics. The results revealed that the relative area of silica xerogels was smaller with a higher coverage of DMS groups. In addition, the thermal decomposition temperature of the silyl group shifted to higher temperatures, and the weight reduction during heating was also relatively limited in the above samples.

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Al-rich cubic (c-) Al_xTi_1−xN (x ≈ 0.8) coating comprising self-organised c-Al(Ti)N/c-Ti(Al)N nanolamellae was prepared in a previous study by low-pressure chemical vapour deposition (LP-CVD) using an AlCl₃–TiCl₄–NH₃–Ar–H₂ precursor system. In the present study, we investigated the effects of isothermal annealing at 800 to 1200°C for 1 to 10 h on the crystal structure, microstructure, and hardness of the coating, and compared them to those of a monolithic c-Al_xTi_1−xN (x ≈ 0.6) coatings prepared by arc-evaporated physical vapour deposition (PVD). The X-ray diffraction patterns indicated high phase stability of the former coating up to 1200°C after 1 h. High-resolution transmission electron microscopy revealed that the nanolamellae in c-Al_xTi_1−xN (x ≈ 0.8) coating remained stable after post-annealing at 900°C for 5 h. The spontaneously formed coherent nanostructure suppressed diffusion in this coating, and the spinodal decomposition and hexagonal phase formation were thus shifted to higher temperatures. Consequently, age hardening in LP-CVD c-Al_xTi_1−xN (x ≈ 0.8) helped to maintain its hardness at up to 1100°C after 10 h. The improved thermal stability and hardness at elevated temperature of the Al-rich c-Al_xTi_1−xN coating by LP-CVD led to a significant improvement in the cutting tool life, by factors of 2 and 10 compared to state-of-the-art CVD- and PVD-coated inserts, respectively. These improvements in thermal stability and elevated hardness in c-Al_xTi_1−xN (x ≈ 0.8) coating prepared via LP-CVD process could remarkably enhance tool life for dry and high-speed cutting applications.

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Thermal properties of superhydrophilic nanocomposite films prepared from polyvinylpyrrolidone and aminopropyl-functionalized clay were studied. The films were treated at various relative humidities to absorb water. They showed excellent water-absorption properties and their capacity (amount of water absorbed from the air) was found to be markedly influenced by the relative humidity. Absorbed water into the films led to enhancement of their thermal diffusivity. Due to the large amount of absorbed water by the films after the treatment at 98%, their thermal conductive properties were considerably improved.

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For lead-free low-melting sealing materials, the boron oxide alkali molybdate glass system was investigated with different boron oxide contents between 0 and 8 mol %. The glasses were characterized using differential scanning calorimetry, and infrared spectroscopy, and by their dissolution rates and densities. As the boron oxide contents increase, the glasses maintain their low temperature properties (T_g under 175°C), and new network formers of [BO₃] triangular units and [BO₄] tetrahedral units appear. The glasses possess MoO₄, MoO₆, BO₃ and BO₄ groups as basic structural units, and existing weak Mo–O–Mo bridge bonds convert into strong Mo–O–B bridge bonds. As a result, chemical durability is improved.

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One-dimensional hydroxyapatite (1D-HAP) particles were synthesized via a hydrothermal process using calcium sodium nitrilotriacetate (CaNa–NTA) as a Ca²⁺ reservoir. CaNa–NTA dissolved slowly at 150°C to enable Ca²⁺ to be supplied to the aqueous phase to react with phosphate and hydroxide ions. The average length and width of the 1D-HAP particles were 6.0 µm and 60 nm, respectively; the former depended on the amount of CaNa–NTA loaded but the latter did not. We investigated the formation of 1D-HAP particles by powder X-ray diffraction measurement and electron microscopy observation.

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