Preparation of Ultra-nano Talcum in Sand Mill and Its Application in the Polypropylene

The grinding of ultra-fine talcum powder and its application in a polypropylene （PP） matrix were investigated. Ultra-fine talcum powder was prepared by adjusting the grinding parameters of the physical milling process. The talcum powder exhibited polymodal distribution. The layered morphology of talcum particles in a horizontal sand mill was rarely damaged or destroyed. PP-talcum nanocomposites were prepared by melt blending using a twin-screw extruder. Nano talcum can be seen as a single particle, although it is not very apparent. The bending strength of talcum-filled PP was gradually increased by approximately 28%. The impact strength linearly decreased as the filler weight ratio increased. The overall maximum improvement in mechanical properties was recorded when the filler ratios increased from 15 wt% to 20 wt%.

Synthesis,Characterization and Properties of LiFePO_4/C Cathode Material

Lithium iron phosphate coated with carbon （LiFePO4/C） was synthesized by improved solid-state reaction using comparatively lower temperature and fewer sintering time. The carbon came from citric acid, which acted as a new carbon source. It was characterized by thermogravimetry and differential thermal analysis （TG/DTA）, X ray diffractometer （XRD）, Element Analysis （EA） and Scanning electron microscope （SEM）. We also studied the electrochemical properties of the material. The first discharge capacity of the LiFePO4/C is 121 mAh·g^-1 at 10 mA·g^-1 at room temperature. When the current density increased to 100 mA·g^-1, the first discharge capacity decreased to 110 mAh·g^-1 and retained 95% of the initial capacity after 100 cycles. The LiFePO4/C obtained shows a good electrochemical capacity and cycle ability at a large current density.

Energy Transfer and Avalanche Upconversion of NdxY1-xVO4 Nanocrystals

We explore Nd3＋ concentration and excitation power dependences of the avalanche upconversion of NdxY1-xVO4 （x=0-1） nanocrystals with uniform size and shape. The avalanche threshold power caused by the near-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→2G9/2 significantly decreases as the Nd3＋ concentration increases. The off-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→4G11/2 in the strong excitation regime leads to apparent broadening on the blue-side of the upconversion spectrum of NdVO4 nanocrystals.

Mass production and application of highly-dispersed nanocrystals

To realize the mass production of highly-dispersed nanocrystalline materials is one precondition for their industrial applications.In this work,the preparation methods and reaction mechanisms developed by our group were introduced.By the engineering amplification,a series of highly-dispersed nanocrystals were produced on batch production.Based on the

Fabrication and Application of Organic/Inorganic Hybrid Thin Films on the Pore Wall of Microporous Polyethylene Separator

Polyolefin materials,such as polyethylene and polypropylene,are the most widely used sep-arators materials in lithium ion batteries due to low cost,proper pore structure,good mechanicalstrength and favorable thermal shutdown property.However,the major disadvantages lie in their intrinsically hydrophobic siuface character。

Interconnected MXene/Graphene Network Constructed by Soft Template for Multi‑Performance Improvement of Polymer Composites

The multi-functionalization of polymer composites refers to the ability to connect multiple properties through simple structural design and simultaneously achieve multi-performance optimization.The large-scale design and mass production to realize the reasonable structure design of multifunctional polymer composites are urgently remaining challenges.Herein,the multifunctional MXene/graphene/polymer composites with three-dimensional thermally and electrically conductive network structures are fabricated via the utilization of the microstructure of the soft template,and a facile dispersion dip-coating approach.As a result,the polymer composites have a multiperformance improvement.At the MXene and graphene content of 18.7 wt%,the superior throughplane thermal conductivity of polymer composite is 2.44 W m^(−1)K^(−1),which is 1118%higher than that of the polymer matrix.The electromagnetic interference(EMI)shielding effectiveness of the sample reaches 43.3 dB in the range of X-band.And the mechanical property of the sample has advanced 4 times compared with the polymer matrix.The excellent EMI shielding and thermal management performance,along with the effortless and easy-to-scalable producing techniques,imply promising perspectives of the polymer composites in the next-generation smart electronic devices.

Kinetics of the Thermal Decomposition of Magnesium Salicylate Powder in Air

Simultaneous thermogravimetry-differential thermal analysis （TG-DTA） was used to study the kinetics and the degradation of magnesium salicylate（ C14H10MgO6 ） in air. The results show that the decomposition proceeds through two steps. The kinetics of the first decomposition step was studied. The activation energies were calculated by using the Friedman and Flynn Wall Ozawa（FWO） methods, and the most probable kinetic model function was estimated using the multiple linear regression method. The values of the correlated kinetic parameters for the first decomposition step are E = 152.97 kJ/mol, lg（A/S^-1 ） = 10. 78, f（α） = （ 1 - α）^n（ 1 ＋Kcatα）, n =0. 691, and Kcat = 1. 3048.

A Sign Alternation of Nonlinear Absorption in Gold Composite Films in Z-Scan

Au-TiO2 composite films with Au atom content varying from about 15% to 82% are prepared by co-sputtering technique. Both open- and closed-aperture Z-scan of the samples are performed in the femtosecond time region. A conversion of the nonlinear absorption from negative to positive is observed as the A u atom content increases due to the saturation of reverse saturable absorption. The nonlinear refractive index γ and effective nonlinear absorption coefficient βeff at the Au atom content of 54% are measured to be 1.6 × 10^-2 cm^2/GW and -2.6 ×10^3 cm/GW, respectively. The corresponding third-order optical nonlinearity X^（3） is about 6.3 × 10^-8 esu.

Advances of high-performance LiNi_(1-x-y)Co_(x)M_(y)O_(2) cathode materials and their precursor particles via co-precipitation process

Layered LiNi_(1-x-y)Co_(x)M_(y)O_(2)(M=Mn or Al)is a promising cathode material for lithium-ion batteries due to its high specific capacity and acceptable manufacturing cost.However,the polycrystalline LiNi_(1-x-y)Co_(x)M_(y)O_(2) cathode material suffers from disordered orientation of primary particles and poor geometric symmetry of secondary particles,which severely hampers the migration of Lit ions.Furthermore,the resulting anisotropy accelerates the disintegration of the secondary particle structure,significantly affecting the electrochemical performance of the polycrystalline cathode.In spite of less grain boundary,the single-crystal LiNi_(1-x-y)Co_(x)M_(y)O_(2) cathodes still suffer from severe microcracks generated by repeated planar gliding during cycling,which poses a great challenge to the cycling stability of single-crystal materials.It's worth noting that the microstructure of the cathode material is mainly inherited from its precursor.Therefore,it is necessary to deeply understand the influence of the microstructure of Ni_(1-x-y)Co_(x)M_(y)(OH)2 on the electrochemical properties of LiNi_(1-x-y)Co_(x)M_(y)O_(2) cathode materials,so as to optimize the production process of preparing high-performance cathode precursors.In this review,we summarize recent advances in the research and development of Ni-rich cathode precursor materials.Firstly,the challenges faced by the Ni-rich hydroxide precursor materials are presented,including the effect of primary particle morphology and arrangement on the electrochemical performance of cathode materials,the influence of secondary particle morphology on lithium insertion reactions in cathode,and the effect of particle size on the microcracking of single-crystal particles.Secondly,the presentation of the conventional co-precipitation reactor,the mechanism of precursor particle growth,and the influence of coprecipitation parameters are described in detail.Finally,the strategies are systematically discussed to solve the challenges of hydroxide precursors,such as the innovation and optimization on reactants,synthesis processes,and reaction equipment.To obtain satisfactory high-quality precursor materials,future work will require an in-depth understanding of the reaction mechanism,combined with simulation techniques such as flow field theory calculations to guide the synthesis of precursors.This review provides a comprehensive analysis of the current progresses on the producing technologies of highperformance cathode precursors and offers prospects for future industry developments.

Study on rare earth/alkaline earth oxide-doped CeO_2 solid electrolyte

Five types of rare earth/alkaline earth oxide-doped CeO2 superfine-powders were synthesized by a low-temperature combustion technique. The relevant solid electrolyte materials were also sintered by pressureless sintering at different temperatures. The results of X-ray diffraction and transmission electron microscopy showed that the grain size of the powders was approximately 20-30 nm, and rare earth/alkaline earth oxides were completely dissolved into ceria-based solid solution with fluorite structure. The electrical conductivities of the SmzO3-CeO2 system were measured by the ac impedance technique in air at temperatures ranging from 513-900℃. The results indicated that the ionic conductivities of Srno.2oCe0.8Ol.875 solid electrolyte increase with increasing sintering temperature, and the relationship between the conductivities and measuring temperature obeys the An＇henius equation. Then the SmzO3-CeO2 material was further doped with other rare earth/alkaline earth oxide, and the conductivities improve with the effective index.

Solvothermal Synthesis of TiO2/Bi2WOs Heterojunction Photocatalyst with Optimized Interface Structure and Enabled Photocatalytic Performance

TiO2/Bi2WO6 （TB） heterojunction photocatalyst was successfully synthesized and characterized by XRD, SEM, TEM, UV-Vis and photoluminescence measurement. The heterojunction interface structure of TB heterojunction photocatalyst was optimized via adjusting the ethylene glycol/water （EG/W） ratio. Based on XRD, SEM and TEM, the crystal size of Bi2WO6 reduced from 14.6 nm to 8.8 nm, and the interface structure between Bi2WO6 nanosheets and TiO2 particle significantly changed with increasing EG concentration. Furthermore, the photoeatalytic activity and the related mechanism of TB heterojunction photocatalyst were systematically discussed. Among them, TBEG/w sample shows the highest normalized apparent rate constant, which is attributed to its highest electron-hole pairs separation ability driven by optimized heterojunction interface between two semiconductors.

Rapid separation of acetophenone and its monohydroxy isomers by capillary electrophoresis

This work describes the development of a capillary electrophoresis （CE） method for the simultaneous separation of acetophenone （AP）, 2-hydroxyacetophenone （2-HAP）, 3-hydroxyacetophenone （3-HAP） and 4-hydroxyacetophenone （4-HAP） in synthetic mixtures using 10 mmol/L of sodium tetraborate buffer （pH 9.5）. The aim of this work is to demonstrate the effectiveness of CE to separate AP and its monohydroxy isomers and to define how the separations are affected by buffers, buffer pH, sample matrices and separation voltage. This method was successfully used for the trace level separation and determination of 2-HAP, 3-HAP and 4-HAP in synthetic mixture and 4-HAP in spiked plasma samples.

Effect of Sn precursor on the synthesis of SnO2 and Sb-doped SnO2 particles via polymeric precursor method

SnO2 and Sb-doped SnO2 particles were synthesized using the polymeric precursor method with different Sn salt precursors： SnCl2.2H2O, SnCl4.5H20, or Sn citrate. Sb2O3 was used as the precursor of Sb, and the molar ratio of nsn：nsb was held constant. FTIR and TGA/DTA were used to examine the influence of the Sn precursor on the formation and thermal decomposition of the Sn and Sn-Sb complexes. The calcination products obtained from heating the Sn and Sn-Sb complexes at 500℃ in air were analyzed using XRD and TEM analysis. The results revealed that the SnO2 and Sb-doped SnO2 formation temperatures depended on the nature of the Sn precursor. The calcination products were found to be SnO2 and Sb-doped SnO2 particles, which crystallized in a tetragonal cassiterite structure with a highly preferred （110） planar orientation. The Sn precursor and the presence of Sb in the SnO2 matrix strongly influenced the crystallinity and lattice parameters.

Influence of activated carbon fibres with different specific surface areas on the thermal conductive and electrical insulating properties of polyamide-imide composites

In this study,the authors reported an influence of activated carbon fibres(ACFs)with different specific surface areas on the thermal conductive and electrical insulating properties of polymeric composites.Here,the polyamide-imide composites were obtained via solution blending and cured method.The composites exhibited thermal conductivity(TC)up to 0.62 W·m^(−1)·K^(−1).In addition,the composites were still insulating,having an electrical resistance of 0.7 MΩ.The experimental results suggested that the mechanical and electrical insulating properties decreased with the increasing of the specific surface area of the ACFs.Meanwhile,it was found that the introduction of boron nitride was conducive to the TC and electrical insulating properties of the polymeric materials.

Magnetic Properties for the Single-domain Co Fe_2O_4 Nanoparticles Synthesized by the Hydrothermal Method

The aim of this work was to investigate the size-related magnetism for the single-domain Co Fe2O4 nano-particles synthesized using the hydrothermal method. The effects of the reaction temperature and the reaction time on the lattice constants, particle morphologies, and the room-temperature magnetic properties were studied from the X-ray diffraction, the transmission electron microscope, and the vibrating-sample magnetometer. The experimental results show that the samples are composed of Co Fe2O4 nano-particles with an average crystallite size（D） smaller than 40 nm, and the magnetic properties of the samples can be manipulated in a wide range： the MS values vary from smaller than 50 emu/g to close to 80 emu/g, and the HC values are between about 200 Oe and 2000 Oe. Additionally, the relationship between HC and 1/D^3/2 satisfi es linearship, showing the characteristic of single-domain structure. These results indicate that the single-domain Co Fe2O4 nano-particles with size controlled between the superparamagnetic critical size and single-domain critical size can be easily prepared using this hydrothermal method.

Influence of defect density on the ZnO nanostructures of dye-sensitized solar cells

The relationship between bilayer nanostructure, defect density and dye-sensitized solar cell （DSCC） per- formances was investigated. By adjusting bilayer nano- structures, defect density of ZnO nanodendrite-nanorods structure was decreased comparing to that of nanoflower- nanorods structure. The performances of DSCC based on ZnO nanodendrites-nanorods structure and nanoflower- nanorods structure were studied by Raman spectrum, room temperature photoluminescence, dye loading, photocurrent density-voltage characteristic and open-circuit voltage decay （OCVD） technique. The device with nanodendrite- nanorods structure has lower charge recombination rate and prolonged electron lifetime due to its microstructure feature.