Hollow silica (SiO₂) microspheres with special interior spaces, excellent adsorption and permeability, and controllability of material deliveries are suitable for loading and releasing guest molecules of various functionalities such as drug, fragrances, dyes, bacteria, etc. More importantly, hollow silica (SiO₂) microspheres have attracted much attention due to their tremendous applications in sustained drug release, medical imaging, environmental protection, and cosmetics industry. In this paper, different preparation methods of hollow silica microspheres are reviewed and compared. Besides, the persistence and efficiency of hollow silica microspheres employed as delivery carriers and superiority of functionalized organic/inorganic hybrid microspheres are emphatically summarized. Meanwhile, the vast potential for future development of hollow silica microspheres as a novel type of sustained/controlled release carriers is prospected.

Electrochemical analysis and diagnosis of the SOC stacks, including Solid Oxide Fuel Cells (SOFC) and Solid Oxide Electrolysis Cells (SOEC), are one of the research challenges in world. In order to optimize performance and realize practical SOC application, it is crucial to investigate kinetic mechanisms and reaction principle of the multiple-cells stack. In this paper, the relaxation time distribution method (DRT) combined with the analysis of difference in impedance spectra method (ADIS) were employed to research the complex electrochemical behavior of SOC stacks under different operation modes. The DRT characteristic peaks were identified through the analysis and as-segment of the relaxation time. The changes in the DRT peaks were correlated with the different electrochemical process. The research achievements indicate that the water content should be more than 20% when operated at SOFC mode, while less than 80% when operated at SOEC mode to minimize the gas diffusion resistance. The research achievements can provide theoretical data and establish technical foundation for the further study and application of this novel method, which can reduce the SOC complexity of EIS analysis, apply for the degradation identification and online diagnosis of stacks, and help to improve the SOC performance.

MoS₂/C composites were prepared by a simple CTAB assistant thermal reduction method using sodium molybdate, thiourea and CTAB as starting materials. The samples were characterized by XRD, SEM, TEM, and TG. It is confirmed that the amorphous carbon is partially inserted into the interlayer spaces of molybdenum disulfide and inhibits the accumulation of (002) plane. Meanwhile, the electrochemical properties were studied in detail. As a consequence, the MoS₂/C composites have better electrochemical performance than pure MoS₂. The composite synthesized by adding 0.025 g CTAB shows the best electrochemical performance. The initial discharge capacity was 730 mAh/g and a stable capacity above 415 mAh/g was retained for 100 cycles tested at 100 mA/g. At last, the possible growth mechanism of the MoS₂/a-C composites and the influence of different micro-morphology are also calculated.

Ti_1.0Cr_1.5V_1.7 alloy was prepared by arc melting and then its morphology and constitution were analyzed by SEM and EDS. The observations showed that the alloy was unhomogeneous with some network-shaped precipitates. The structures of the hydrides of Ti_1.0Cr_1.5V_1.7 were determined by XRD. The structures of the hydrides depended only on the hydrogen content, not on the kind of hydrogen isotopes. The dependences of separation factor (α_H-D) on pressure, deuterium concentration and temperature were investigated systematically. Not significantly influenced by pressure, α_H-D decreased with the increase of deuterium concentration. However, the dependence of α_H-D on temperature was complicated. In 213-373 K, α_H-D increased with the decrease of temperature, which agreed with the harmonic oscillator model (HOM). In 77-213 K, the experimental α_H-D was different from the calculated value of HOM. According to the results of DSC measurement for the hydrides of Ti_1.0Cr_1.5V_1.7 alloy, the disagreement between the experiments and the HOM in 77-213 K was not induced by phase transitions. Moreover, the maximum α_H-D reached 2.29 at 213 K.

Ceramic-coating separators were prepared with poly(ethylene terephthalate) (PET) nonwoven membrane as the substrate. Different particle sizes and variable ratios of SiO₂ and Al₂O₃ were coated on the PET surface by dip coating technology, using PVDF-HFP as the binder. The separators took advantage of both kinds of ceramic particles, so that the big pores of PET were filled more effectively. Surface morphology, porosity, electrolyte wettability, thermal stability, ionic conductivity, and electrochemical impedance spectroscope (EIS) of composite separators with different ratios of SiO₂ to Al₂O₃ were systematically investigated, and separators with ratio of SiO₂/Al₂O₃=3/7 showed superior performance. Electrochemical properties of MCMB / LiNi_1/3Co_1/3Mn_1/3O₂ 2025-type coin cells assembled by the ceramic separators with ratio of SiO₂/Al₂O₃=3/7 were also tested, as compared with commercialized PP separators. The results demonstrated that the ceramic separators performed with 93.9% capacity retention after 100 cycles and capacity of 82.7 mAh/g at 10C rate, better than PP separators.

The Gelatin/BaTiO₃ core-shell composite particles were prepared by directional sedimentary self-assembly on the gelatin microspheres with an average particle size about 0.7-0.9 mm. Morphology, structure, composition, and surface hydrophile of the particle were characterized by TEM, XRD, FT-IR, TG, and optical contact angle measuring instrument. The results show that the composite particles are spherical with hydrophilic surface and good dispersion, of which cubic BaTiO₃ shell accounts for about 18.8% of the total weight. After BaTiO₃ and Gelatin/BaTiO₃ particles being dispersed into gelatin hydrous elastomers cured with/without an electric field, the difference of storage modulus of the elastomers suggests that Gelatin/BaTiO₃ composite particles have stronger electro response than pure BaTiO₃ particles. These data demonstrate that coating polymer with BaTiO₃ significantly can improve BaTiO₃ particles electro response.

The Si-Zr-B doped coal-tar pitch was synthesized by co-pyrolysis of xylene soluble pitch, silicon carbide precursor, zirconium boride precursor, and zirconium carbide precursor. The pitch-based carbon materials doped with Si-Zr-B were prepared through co-carbonization, cold moulding and followed by high temperature heat treatment from the obtained Si-Zr-B doped coal-tar pitch. The phase composition and microstructure of the carbon materials were characterized by XRD, SEM and EDS. The oxidation behavior of specimens was tested at 1500℃ in static air. The results show that weight loss of the doped carbon materials is increased firstly and then decreased with the decrease of content of silicon carbide precursor in Si-Zr-B doped coal-tar pitch. The doped carbon materials obtained from Si-Zr-B doped coal-tar pitch, with a mass ratio of the polycarbosilane, zirconium carbide precursor and zirconium boride precursor at 1:2:1, shows an excellent oxidant resistance. After oxidation in air at 1500℃ for 4 h, its weight loss and oxidation depth is 27.5wt% and 0.7 mm, respectively. A dense SiO₂-ZrO₂-B₂O₃ glassy oxide layer which formed during oxidation in air can effectively reduce the rate of oxygen diffusion and thus improve the oxidation resistance of the carbon materials derived from the doped coal-tar pitch.

The transformation from SiCO(Al) fiber to SiC(Al) fiber by high temperature heat-treatment was studied. The characteristics of SiC_xO_y decomposition and effects of different heating approaches on microstructure and densification processing of SiCO(Al) fibers were investigated. It was found that SiC_xO_y phase typically decomposed at temperature ranged from 1430℃ to 1850℃. The SiC_xO_y phase in the core area of fiber could not be eliminated completely by continuous heat-treatment, even at the temperature as high as 1800℃. Furthermore, large pore faults and grain coarsening tended to generate in the fibers due to over-high decomposition rate, which led to loose structure of fibers. By contrast, static heat-treatment could increase the degree of SiC_xO_y decomposition. The SiC_xO_y phase could be completely removed when the fibers were heat-treated at 1650℃ for 1 h, and big pores and heterogenous grains were suppressed. Finally, densified SiC(Al) fibers with large β-SiC grains could be achieved after sintering at 1900℃.

Based on the model of pyrolytic carbon matrix texture formation and transformation in CVI for densification of carbon/carbon composites, a new model was constructed to describe the surface of pyrolytic carbon deposited in a honeycomb structure pores. This new model is related with structure characteristics of graphite microchip. The Monte Carlo method is applied to simulate the pyrocarbon deposition kinetics and to analyze the influence of surface area/volume (A_S/V_R) and gas pressure on the texture of pyrocarbon in the process of isothermal-isobaric chemical vapor infiltration (ICVI). According to the numerical simulation results, under certain conditions of pressure, various textured carbon were obtained by controlling A_S/V_R in CVI process. Between two critical values (1.45 mm^-1 and 8.9 mm^-1 near the inlet, 0.3 mm^-1near the outlet) of A_S/V_R, the high-textured carbon can be obtained. Moreover, if A_S/V_R is certain value and pressure is less than 30 kPa, pyrolytic medium and high textured carbon texture can be obtained as a result of different pressure in CVI process. There is also a critical pressure value and the high-textured carbon can be obtained if the pressure is greater than the critical value.

One-step hydrothermal reaction and complexation method was used to prepare the extra uniform γ-Fe₂O₃ nanoparticles@multi-layer graphene, which was unnecessary to introduce oxygen function group on graphene. Multi-layer graphene was prepared by simple sonication method that will not introduce rich oxygen functional groups on its surface. Reagent FeCl₂, mixture solvent DMF and water were used for hydrothermal reaction, in which DMF could form complexion with metal ion. The effects of sodium acetate, reaction temperature and filling ratio on the prepared product were studied. X-ray diffraction(XRD), X-ray photoelectron spectroscope(XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to analyze the microstructures of the composite materials. The magnetic properties of the composites were measured by vibrating sample magnetometer (VSM). The results show that π-π reaction between carbon ring and complexation of Fe²⁺ with DMF can be used to prepare iron oxide on the multi-layer graphene. Homogeneous γ-Fe₂O₃ nanoparticles with size less than 10 nm can be prepared through the control of oxidation speed of Fe²⁺ and growth velocity of iron oxide, with good magnetic properties.

Hydroxyapatite (HA) has been widely used as artificial bone substitutes because of its good biological activity, but the disadvantages of pure HA have limited its clinical applications. In human natural hard tissues, there are many trace elements doped in hydroxyapatite, which play beneficial roles in biological actions. In this study, multi-doped nanostructured hydroxyapatite (HA₂) was synthesized by doping trace elements in HA according to the contents in human bones. Alkaline phosphatase activity staining, semi-quantitative PCR measurement (ALP, OCN and OPN) and alizarin red staining were carried out to detect the effect of pure nanostructured hydroxyapatite (HA₁) and multi-doped nanostructured hydroxyapatite (HA₂) on proliferation and differentiation of MC3T3-E1cells. Alkaline phosphatase activity experiments prove that the HA₂ has a stronger role than HA₁ in promoting cell production. Semi quantitative PCR measurement confirms that HA₂ is more effective than HA₁ in promoting the expression of osteogenic genes. Alizarin red staining results show that HA₂ is better than HA₁ for MC3T3-E1 cells to produce mineralized nodules. Multiple-doped nanostructured hydroxyapatite (HA₂) has an obvious promoting effect on the differentiation and osteogenesis of MC3T3-E1 comparing with the undoped nanostructured HA₁. Multi-doped nanostructured hydroxyapatite (HA₂) is more beneficial to bone formation, which has the inorganic composition more close to human bone and is a promising biomaterial for human hard tissue implants.

Pristine multiwalled carbon nanotubes (MWCNTs) were modified by sodium dodecyl sulfate (SDS). Afterwards, a series of MnO₂/MWCNTs were prepared via a redox method and used in selective catalytic reduction (SCR) of NO_x at 80-180℃. Structural properties and catalytic performance were investigated by specific surface area measurements (BET), X-ray diffraction (XRD), filed emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray photoelectron spectroscope (XPS), and H₂ temperature-programmed reduction (H₂-TPR). The characterization results indicate that the nanoflaky MnO₂ highly disperse on MWCNTs. The results show that the low-temperature SCR activities of MnO₂/MWCNTs catalysts are 85%-100% at 140-180℃ at a weight hourly space velocity of 210 L/(g_cat·h), higher than that of catalyst fabricated via the wet impregnation method. The 10% MnO₂/MWCNTs catalyst displays first-rate SCR activity, which is attributed to its low crystallinity, high concentrations of Mn⁴⁺ and oxygen absorbtion onto the catalyst surface, as well as excellent reducibility. Additionally, compared to the MnO_x/MWCNTs catalyst, the 10% MnO₂/MWCNTs catalyst exhibits higher resistance to H₂O and SO₂.

Mordenite is generally referred to be a one-dimensional micropore zeolite. The major drawback of this pore structure is severe diffusion limitations, especially for the reactions involving bulky molecules. Herein, hierarchical mordenites were successfully prepared through a soft-templating method using a diquaternary ammonium surfactant [C₁₈H₃₇N⁺(CH₃)₂C₆H₁₂N⁺(CH₃)₂C₆H₁₃(Br^-)₂, C_18-6-6Br₂ for short] as mesoporogen. The obtained samples were characterized by XRD, FT-IR, SEM, TEM, TG-DTG, N₂ physical adsorption, and NH₃-TPD techniques. The results show that the hierarchical mordenites with nanorods (20-40 nm in width) oriented-assembled structures are synthesized in the presence of the C_18-6-6Br₂ surfactant. Moreover, the crystal sizes, mesopore surface areas and mesopore volumes of hierarchical mordenites can be systematically tuned by changing the C_18-6-6Br₂/SiO₂ ratios. More importantly, the hierarchical mordenites exhibit much higher catalytic activity and faster reaction rate in the benzylation of benzene with benzyl alcohol than the conventional mordenite. The remarkably enhanced catalytic performance of hierarchical mordenites may be attributable to the more accessible acid sites and much better mass transfer properties with the presence of mesopore. Thus, the special hierarchical mordenites reported here show a great potential for catalytic conversions involving bulky molecules.

Dy³⁺, Cr³⁺ co-doped ZnGa₂O₄ persistent luminescence nanoparticles (PLNPs) with long near-infrared afterglow were synthesized by an ethylene glycol assisted hydrothermal method. Persistent luminescence properties of the PLNPs are improved and size of the PLNPs is controlled efficiently via optimization of reaction condition, modification of zinc ratio and co-doping of Dy³⁺ ion. The results show that the PLNPs have long afterglow time more than 72 h and small grain size of approximately 6 nm, when the pH of the reaction solution, Ga:Zn ratio and doping amount of Dy³⁺ are 7, 2:1.2 and 1%, respectively. The as-prepared PLNPs exhibit great potential as a molecular probe for biomedical imaging with high signal to noise ratio.

Carbon nanotubes/black nickel composite coatings with high optical properties on titanium alloy substrate were prepared on the basis of composite electrochemical deposition methods. Micro scale morphology and optical properties of as-prepared materials were analyzed. The effects of carbon nanotubes concentration and electroplating current density on the optical properties were also explored. The results show that grain size of composite coating was small with microporous and increased surface roughness as compared with conventional black nickel coating. The absorptance (α_s) over a spectral range of 300-2300 nm was up to 98%, while the emittance (ε) over a 2.5 µm to 20 µm range was 94%, better than those of conventional black nickel coatings. The absorptance of composite coating increased firstly and then decreased with increase of carbon nanotubes concentration and electroplating current density.

The cost-effective fabrication of CoSb₃-based filled skutterudites (SKD) thermoelectric materials is a bottleneck issue preventing their successful commercial application. In this study, we employed a simple and scalable process to simultaneously produce a rapid formation and consolidation of n-type filled skutterudites. This method, consisting of RF-induction melting, quenching and spark plasma sintering (SPS), required less than a half-hour, significantly shorter than conventional process of furnace melting (over 24 h), annealing (about one week) and SPS. The fabricated bulk SKD materials possessed homogeneous composition and structures with a good thermoelectric performance which are analogous to those materials fabricated according to a conventional process. The homogeneous microstructures and phase composition distribution which was a result of the simultaneously proceeded rapid reaction and densification of the grinding-destructed dendrite networks of the Sb/CoSb/CoSb₂ peritectic structure formed in the RF-induction melting and quenching. The good thermoelectric TE performance and the very low consumption of process time and energy would make this simple process a potential and practical method for industrial-level mass production of filled skutterudite thermoelectric materials.