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After undergoing microarc oxidation, titanium alloys exhibit significantly enhanced biocompatibility, making them a subject of extensive research in the field of biomedical applications. In this study, a two-step microarc oxidation method was used to prepare a film layer with both macro-micro-nano tertiary structures on β-type titanium alloy Ti-3Zr-2Sn-3Mo-25Nb (TLM), using a phosphate-nitrate mixed electrolyte for the first step of microarc oxidation and a borate body electrolyte for the second step of microarc oxidation. The effects of NaOH concentration, microarc oxidation voltage, and time on the size and distribution of macropores prepared by microarc oxidation in the first step were investigated by SEM, energy dispersive spectroscopy, XRD, and metallurgical microscopy. The wettability of the prepared three-level structured film and its ability to induce hydroxyapatite deposition were evaluated through contact angle testing and simulated body fluid immersion experiments. The overall research findings indicate that the two-step microarc oxidation process yielded macropores with diameters ranging from 200 to 400 μm, along with micro-nanostructures measuring 2–15 μm and 10–100 nm. The increase in the NaOH concentration in the electrolyte decreased the size of the macropores. The increase in the microarc oxidation time increased the size of macropores; the voltage affected the distribution and number of macropores. The prepared macro-micro-nano tertiary structured membrane layers have excellent wettability and the ability to induce hydroxyapatite precipitation, indicating that they possess good biocompatibility. This study provides a reference for the medical development of alloys. [ABSTRACT FROM AUTHOR]

In this experiment, we investigated the effects of different reactions on the growth process and morphology of h-MoO3 and α-MoO3, and their optical properties and photocatalytic activities were also investigated. Orthogonal experiments were designed to investigate the effects of four influencing factors, namely the amount of ammonium molybdate tetrahydrate (AHM), the type of acid, the reaction temperature and the holding time, on the morphology of h-MoO3 by a microwave hydrothermal method. The phase and morphology were analyzed by using advanced physicochemical techniques. The XRD results showed that the samples produced by the microwave hydrothermal method had sharp diffraction peaks, high crystallinity and complete crystalline shape. AHM generates h-MoO3 in both hydrochloric and nitric acid environments. In particular, when the temperature rises to 200 °C, the generated h-MoO3 will be converted to α-MoO3 in a nitric acid environment, which will be generated in a sulfuric acid environment. Therefore, increasing the reaction temperature will result in the conversion of h-MoO3 to α-MoO3 in sulfuric acid solution. SEM results show that the sample prepared from hydrochloric acid solution has a complete hexagonal prism morphology, while the sample prepared from sulfuric acid solution presents a long fibrous morphology, and the sample prepared from nitric acid solution has many defects on the surface of the hexagonal prism morphology. Interestingly, sample A11 prepared in nitric acid solution showed a spherical structure. Since the generated A3, A6 and A9 samples are all stable phase α-MoO3, they have a wider band gap compared with other samples. Their particle size is up to the nanometer scale, so they have strong adsorption properties. The spherical sample A11 has excellent adsorption and photocatalytic activity. [ABSTRACT FROM AUTHOR]

Summary: Compared with current research of simply improving the efficiency of thermal absorber or thermal storage, integrating two devices into one fundamentally avoids the heat transfer loss between the two devices. In‐situ self‐assembled SiCw(SiC whisker)/SiC composite ceramics for integrated thermal absorber and thermal storage were pressurelessly prepared from graded SiC, AlN, and Si powders by layered powder embedded sintering in a low temperature range from 1450°C to 1650°C. After sintered at 1550°C, sample A4 with 10.39 wt% Si not only exhibits optimal mechanical properties and excellent thermal shock resistance, but also has high thermal conductivity, thermal storage capacity, and solar absorptance as 6.74 W·(m K)−1, 984.75 kJ·kg−1, and 91.12%, respectively. Results indicate that the in‐situ self‐assembled SiC whiskers, formed by carburization reaction via VS mechanism in the stacking voids of SiC matrix, could greatly enhance the mechanical and thermal properties. We creatively proposed that the as‐prepared SiCw/SiC is promising to apply in integrated thermal absorber and storage system of solar thermal power generation. [ABSTRACT FROM AUTHOR]