In this article, red emitting β-Ca₃(PO₄)₂:Eu³⁺ phosphors were synthesized by conventional solid state method, phase transformation and photoluminescence at different temperatures and Eu³⁺ concentrations were discussed. Effect of co-doping alkali metal ions A⁺ (A = Li, Na, K) on the structure and luminescent properties of Ca₃(PO₄)₂:Eu³⁺ phosphor was investigated and compared, Li⁺ ion is confirmed to be the most suitable charge compensator for Ca₃(PO₄)₂:Eu³⁺ phosphor. The fabrication of a prototype red light emitting diode show the prepared Ca₃(PO₄)₂:Eu³⁺ phosphor compensated by Li⁺ ion can be considered as a more promising red candidate used for near ultraviolet chip based light emitting diodes.

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Two types of petal-effect hafnia films and hydrophilic-hydrophobic stripe-patterned films consisting of 1-mm-wide lines and spaces were fabricated and their water harvesting capability was investigated. Petal-effect hafnia films containing glycine and glycolic acid were prepared by a sol–gel technique. Hydrophilic-hydrophobic stripe-patterned films were fabricated by screen printing a hydrophobic hafnia sol as a paste onto a superhydrophilic alumina film substrate. The water harvesting capability of the films was evaluated using a custom-built water collecting apparatus. The mass of water both on the sample surface and in a petri dish set under the sample was measured to evaluate the water collecting capability. When a vapor covered the petal-effect film, small dew droplets formed on the surface and grew to large hemispheric ones, but most of the water remained on the sample surface without falling into the petri dish. When a vapor covered the patterned film surface, small droplets and large, long ones formed on the hydrophobic and hydrophilic patterns, respectively. The large droplets that grew on the hydrophilic patterns fell into the petri dish. The total amount of water that collected on the petal-effect films and the patterned films was ca. 1.6 times larger than the respective amount collected with a superhydrophilic alumina film, a hydrophobic hafnia film and a glass substrate as a control reference. The patterned films collected a larger amount of water in the petri dish than the petal-effect films did because the hydrophilic molecules of organic acids on the surface of the latter films retained a larger amount of droplets. It is concluded that both the petal-effect films and the patterned films have superior water harvesting capability from a vapor in the ambient atmosphere.

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Nanosized anatase TiO₂ crystals were rapidly prepared in a mixture of an ionic liquid (1-butyl-3-methylimidazolium chloride) and water under microwave irradiation for 5 min. The crystal size in the c axis was varied in the range from ~5 to ~17 nm with prolongation of the irradiation time. A high susceptibility of the ionic liquid to microwave and a catalytic property of the imidazolium cation are effective for the rapid synthesis of the highly crystalline nanosized particles.

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Barium titanate is a potential lead-free piezoelectric ceramic with high dielectric and piezoelectric constants. In this study, the reaction behavior of a mixed powder of BaCO₃ and anatase TiO₂ was investigated by using high-temperature X-ray diffraction analysis. Frequency and temperature dependences of the dielectric constant were studied for the reactively-sintered BaTiO₃ ceramics. Relatively high piezoelectric constant (d₃₃ ~120 pC/N) was obtained for BaTiO₃ reactively-sintered at 1300°C for 2 h, even with a density only of ~85%, which implies the future improvement for reactively-sintered BaTiO₃.

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Nano ZrO₂–TiN (10–40 vol.%) composites were successfully fabricated by spark plasma sintering (SPS) at 1200°C under 80 MPa. The as-obtained composites remained nanosized grains of ZrO₂ and TiN below 200 nm. The physical and mechanical properties of composites were systemically investigated. It was found that above 20 vol.% TiN the composites were electrically conductive. 30 and 40 vol.% TiN reinforced composites possessed the highest flexural strength of 1459.7 MPa and maximum electrical conductivity of 17081.7 S·m⁻¹ respectively.

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Regenerated MgO–CaO refractory brick samples were prepared from spent MgO–CaO bricks and fused magnesia. Hydration resistance was investigated by hot water experiment, and its hydration reaction mechanism and hydration kinetic model were explored. The results showed a superior hydration resistance of regenerated samples. Ca(OH)₂ was the only new generated phase after the hot water experiment, and it is indicated that the hydration of free CaO was the key point. Impurity elements Si, Fe, Al in the spent MgO–CaO bricks had enhanced the hydration resistance through decreasing free CaO content and improving the density of regenerated samples. Meanwhile, it is found that hydration reaction mainly occurred on the surface of regenerated samples, which was controlled by diffusion of H₂O, and the diffusion rate constant K was 0.70 × 10⁻⁶ s⁻¹.

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The effects of B₂O₃ on the crystallization behavior of ZnO–Al₂O₃–SiO₂ glasses were investigated by DTA and XRD measurements after nucleation heat-treatment (NHT) at various temperatures for 24 h. The addition of B₂O₃ also decreased T_c of glasses. According to XRD measurements, gahnite precipitated as main phase in every composition. Precipitation of quartz or willemite was observed for the glass in which little nucleation occurred because of low NHT temperature. Addition of B₂O₃ promoted the precipitation of willemite instead of quartz. However, the precipitation of these phases was not observed when the nucleation was enough. Crystal sizes became smaller with the increase of the number density of nuclei. On the other hand, they became larger by the addition of B₂O₃. It was found that B₂O₃ addition decreases the nucleation rate and increases the crystal growth rate.

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