Preparation of La1-xSrxMnO3 Materials by High Temperature Solid Phase Method

2012 ◽  
Vol 562-564 ◽  
pp. 482-485
Author(s):  
Zeng Gang Li ◽  
Zeng Yong Chu ◽  
Yong Jiang Zhou ◽  
Hai Feng Cheng
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
High Temperature ◽  
Solid Phase ◽  
Average Particle Size ◽  
Phase Method ◽  
Average Particle ◽  
Structure And Morphology ◽  
Solid Phase Method ◽  
Perovskite Type

La1-xSrxMnO3 (LSMO) (x=0.1, 0.2, 0.3, 0.4)powders were synthesized by high temperature solid phase method, and the crystal structure and morphology were characterized by XRD and SEM. Results indicated that the pure perovskite type LSMO could be obtained after sintered at the temperature of 1000°C for 6h. The average particle size of the powders decreases with the increasing concentration of Strontium.

Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Hydrothermal Method ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

Synthesis and Electrochemical Performance of LiFe1-xMnxPO4/C Cathode Material

2011 ◽  
Vol 347-353 ◽  
pp. 3434-3438
Author(s):  
Yan Jun Wei ◽  
Guang Chuan Liang ◽  
Li Wang ◽  
Xiu Qin Ou
Keyword(s):  
High Temperature ◽  
Electrochemical Performance ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Specific Energy ◽  
Solid Phase ◽  
Constant Current ◽  
Phase Method ◽  
Solid Phase Method ◽  
Constant Current Charging

Olivine LiFe1−xMnxPO4/C composites were prepared by high temperature solid phase method using MnO2, NH4H2PO4, Li2CO3, FeC2O4•2H2O, glucose as the starting materials. XRD, SEM and constant-current charging/discharging tests were used to study the structure and electrochemical properties of the material. The result showed that when x=0.2 the material exhibited the optimal electrochemical performance, with a higher specific energy of 484.94 Wh/kg.

scholarly journals 3D Online Submicron Scale Observation of Mixed Metal Powder's Microstructure Evolution in High Temperature and Microwave Compound Fields

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Dan Kang ◽  
Feng Xu ◽  
Xiao-fang Hu ◽  
Bo Dong ◽  
Yu Xiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
High Temperature ◽  
Microstructure Evolution ◽  
Diffusion Mechanism ◽  
Average Particle Size ◽  
Average Particle ◽  
Reconstruction Method ◽  
Neck Size ◽  
Submicron Scale

In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37 μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

Research on Electrochemical Properties of LiMnPO4 Synthesized by High Temperature Solid-Phase Method

2012 ◽  
Vol 487 ◽  
pp. 714-718 ◽  
Author(s):  
Sheng Kui Zhong ◽  
Ying Mei Zhang ◽  
Wei Li ◽  
Yue Bin Xu
Keyword(s):  
High Temperature ◽  
Solid Phase ◽  
Raw Materials ◽  
Particle Surface ◽  
Lithium Ion ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Phase Method ◽  
Solid Phase Method ◽  
Olivine Structure

LiMnPO4cathode material for lithium ion batteries was synthesized by high temperature solid-phase method using MnCO3, Li2CO3, NH4H2PO4as raw materials. The structure of samples was identified by XRD analysis and the particle surface morphology was examined by SEM. The results of XRD showed that the LiMnPO4sample sintered at 700°C for 20h had single ordered olivine structure. The SEM pattern showed that spherical particles distributed uniformly. Respectively, it figured out that the initial charge and discharge capacities of the samples at 0.05C rate were 133.9 and 66.4mAh•g-1.

scholarly journals Preparation, characterization, and in vitro evaluation of amphiphilic peptide P12 and P12-DOX nanomicelles as antitumor drug carriers

2020 ◽  
Vol 10 ◽  
pp. 184798042091151 ◽  
Author(s):  
Ping Song ◽  
Wuchen Du ◽  
Wanzhen Li ◽  
Longbao Zhu ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Solid Phase ◽  
Average Particle Size ◽  
In Vitro Release ◽  
Drug Carriers ◽  
Average Particle ◽  
Polymer Micelles ◽  
Amphiphilic Peptide

Polymerized polypeptide nanomicelles have attracted much attention as novel drug carriers because of their good biocompatibility and degradability. To prepare doxorubicin (DOX)-loaded nanomicelles, an amphiphilic peptide, FFHFFH-KKGRGD (P12), was synthesized by solid-phase synthesis, and the physicochemical and drug-release properties, as well as the cytotoxicity of the nanomicelles, were evaluated in vitro. The P12-DOX polymer micelles were prepared by dialysis. The morphology and particle size were characterized by transmission electron microscopy and dynamic light scattering. The critical micelle concentration (CMC) of the polymer was determined by the probe method, and the drug-release characteristics of the micelles were studied by dynamic dialysis. The cytotoxicity and uptake of the P12-DOX micelles were evaluated against mouse breast cancer cells (4T1) and human umbilical vein endothelial cells. The peptide polymer micelles containing DOX were uniformly sized and had a spherical core–shell structure with an average particle size of 128.6 nm. The CMC of the polymer was low (0.0357 mg/mL). The in vitro release of DOX from the micelles is slow and is consistent with first-order kinetics. The copolymer micelles of the P12 polypeptide and DOX can be used as nanoscale spherical carriers of hydrophobic drugs and have broad applicability.

Activation of Corn Starch and Effect of the Activation on its Reactivity

2012 ◽  
Vol 549 ◽  
pp. 183-187 ◽  
Author(s):  
Yan Wang ◽  
Jia Ying Xin ◽  
Tie Liu ◽  
Kai Lin ◽  
Chao Yue Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Solubility ◽  
Corn Starch ◽  
Cold Water ◽  
Molecular Level ◽  
Chemical Reactivity ◽  
Level Structure ◽  
Average Particle Size ◽  
Average Particle ◽  
Structure And Morphology

Native corn starch (NS) was activated by treatment with NaOH /Urea /H2O solution at low temperature to improve its chemical reactivity. Effects of the activation on the molecular level structure and morphology of the corn starch were investigated by mean of SEM. It was found that the average particle size of activated corn starch (AS) decreased to nanometer level, smaller than those of NS. The cold water solubility (CWS) has been increased from 0.45% to 96.4%. Effects of the activation on reactivity of the corn starches were investigated by analyzing the influences of the activation on degrees of substitutions (DS) of the esterifications. The DS of AS was higher than that of NS, from 0 to 0.1578, which indicated that NaOH/urea activation enhanced the chemical reaction activity of corn starch.

Stability and particle size of polypyrrole dispersion using sodium dodecylbenzenesulfonate as surfactant

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Shuangxi Xing ◽  
Guoku Zhao
Keyword(s):  
Particle Size ◽  
Driving Forces ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images ◽  
Sodium Dodecylbenzenesulfonate ◽  
Structure And Morphology ◽  
Preparation Conditions ◽  
Pyrrole Monomer ◽  
The Stability

AbstractPolypyrrole (PPy) dispersion was prepared using FeCl3·6H2O as oxidant in the presence of sodium dodecylbenzenesulfonate (SDBS) as surfactant. The formation of the micelles and the electrostatic interaction between PPy and SDBS were considered the driving forces for the formation and stability of the dispersion. UV/Vis/NIR, FTIR spectra and SEM images were studied to confirm the structure and morphology of the PPy dispersion, respectively. Polymerization of pyrrole under different preparation conditions including the concentration of the surfactant, the pyrrole monomer and the oxidant and also the addition of acid were carried out in order to investigate their effects on the stability and average particle size of the dispersions. The conductivity of the resulting PPy particles was measured and a comparison between the PPy and polyaniline dispersion formed with SDBS as surfactant was also given.

scholarly journals Improved Electrochemical Properties of LiMn2O4-Based Cathode Material Co-Modified by Mg-Doping and Octahedral Morphology

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2807 ◽  
Author(s):  
Hongyuan Zhao ◽  
Yongfang Nie ◽  
Dongyang Que ◽  
Youzuo Hu ◽  
Yongfeng Li
Keyword(s):  
High Temperature ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Solid Phase ◽  
High Capacity ◽  
Temperature Cycling ◽  
Phase Method ◽  
Mg Doping ◽  
Jahn Teller ◽  
Solid Phase Method

In this work, the spinel LiMn2O4 cathode material was prepared by high-temperature solid-phase method and further optimized by co-modification strategy based on the Mg-doping and octahedral morphology. The octahedral LiMn1.95Mg0.05O4 sample belongs to the spinel cubic structure with the space group of Fd3m, and no other impurities are presented in the XRD patterns. The octahedral LiMn1.95Mg0.05O4 particles show narrow size distribution with regular morphology. When used as cathode material, the obtained LiMn1.95Mg0.05O4 octahedra shows excellent electrochemical properties. This material can exhibit high capacity retention of 96.8% with 100th discharge capacity of 111.6 mAh g−1 at 1.0 C. Moreover, the rate performance and high-temperature cycling stability of LiMn2O4 are effectively improved by the co-modification strategy based on Mg-doping and octahedral morphology. These results are mostly given to the fact that the addition of magnesium ions can suppress the Jahn–Teller effect and the octahedral morphology contributes to the Mn dissolution, which can improve the structural stability of LiMn2O4.

scholarly journals Exothermic synthesis and consolidation of single-phase ultra-high temperature composite Ta4ZrC5

2019 ◽  
Vol 488 (2) ◽  
pp. 153-156
Author(s):  
V. A. Shcherbakov ◽  
A. N. Gryadunov ◽  
S. G. Vadchenko ◽  
M. I. Alymov
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
High Temperature ◽  
Ceramic Composite ◽  
Single Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
Refractory Compounds ◽  
Isostatic Compression ◽  
Ultra High Temperature

The paper presents the experimental results of possibility obtaining ultra-high temperature composite Ta4ZrC5 using a single-stage method. The method is based on the use of exothermic synthesis of refractory compounds by electro-thermal explosion (ETE) and their consolidation under conditions of quasi-isostatic compression. The effect of mechanical activation of the reaction mixture of tantalum, zirconium and carbon powders on the formation of the phase composition of the ceramic composite Ta4ZrC5 was studied. The conditions for obtaining a single-phase ultra-high temperature composites had were determined. The composites were prepared with the average particle size of 1-2 µm and a residual porosity of 8-10%.

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