Experimental Research of Al2O3 Micro-Particles Production by Supercritical Hydrolysis

2012 ◽  
Vol 268-270 ◽  
pp. 464-467
Author(s):  
Yan Jie Zhang ◽  
Xue Yong Wang ◽  
Yan Fang Yang
Keyword(s):  
Particle Size ◽  
Average Diameter ◽  
Total Flux ◽  
Small Particle Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Particles ◽  
Particle Size Analyzer ◽  
Increasing Trend ◽  
Α Al2o3

Because of the excellent specialties of intensity, rigidity, heat-durability, corrosion proof and wide uses in many fields, Al2O3 has a promising future. Supercritical hydrolysis is a new method to produce Al2O3 micro-particles whose average diameter is 537nm. The resulting samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Particle-size Analyzer. Its product is the high purity α-Al2O3 which is characterized by the features of the small particle size, the well developed dispersion, and the fine concentricity. The influences of process parameters, including pressure, temperature，total flux and ratio of branch flux, on particle size were investigated at the same time. The results indicated that the particle size has a significant increasing trend with an increase in the pressure and temperature; however, it decreased with an increase in the total flux, while it decreased slightly with an increase in the ratio of branch flux.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

scholarly journals Preparation and Properties of Ginger Essential Oil β-Cyclodextrin/Chitosan Inclusion Complexes

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 305 ◽  
Author(s):  
Yan Zhang ◽  
Hui Zhang ◽  
Fang Wang ◽  
Li-Xia Wang
Keyword(s):  
Particle Size ◽  
Essential Oil ◽  
Spray Drying ◽  
Small Particle Size ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Scanning Electron

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.

scholarly journals Synthesis of Silver Nanoparticles Using Muntingia Calabura L. Leaf Extract as Bioreductor and Applied as Glucose Nanosensor

2018 ◽  
Vol 34 (6) ◽  
pp. 3088-3094 ◽  
Author(s):  
Abdul Wahid Wahab ◽  
Abdul Karim ◽  
Nursiah La Nafie ◽  
Nurafni Nurafni ◽  
I. Wayan Sutapa
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Measurement Range ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Muntingia Calabura

Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. leaf a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vis method. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R2) is 0,9516, the detection limit of sensor is 3,2595 mM, the sensitivity of sensor is 2,0794 A. mM-1. mM-2.

CYCLIC IMPROVEMENT OF LiNi0.5Mn1.5O4 POLYHEDRAL SPINELS FOR 5.0 V LITHIUM ION BATTERIES

2010 ◽  
Vol 03 (03) ◽  
pp. 185-188 ◽  
Author(s):  
XIAOYUN ZHAN ◽  
ZHAOHUI LI ◽  
JIAOJUN TANG ◽  
QIZHEN XIAO ◽  
GANGTIE LEI ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Lithium Ion ◽  
Electrochemical Measurement ◽  
Cycling Performance ◽  
Small Particle Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Highly crystallized and microsized particles of LiNi0.5Mn1.5O4 spinels with different morphologies have been successfully synthesized using polystyrene (PS) as the sacrificial template, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurement. The spinels obtained at 700°C possess abundant porosity with about 200 nm in diameter, while the spinels calcined at 900°C exhibit a well-defined polyhedral morphology with particle size ranged from 0.2 to 2 μm. The materials prepared at 900°C display an excellent cycling performance due probably to better crystallinity and small particle size.

scholarly journals Novel NiMgOH-rGO-Based Nanostructured Hybrids for Electrochemical Energy Storage Supercapacitor Applications: Effect of Reducing Agents

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1144
Author(s):  
Konda Shireesha ◽  
Thida Rakesh Kumar ◽  
Tumarada Rajani ◽  
Chidurala Shilpa Chakra ◽  
Murikinati Mamatha Kumari ◽  
...  
Keyword(s):  
Particle Size ◽  
Cyclic Voltammetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Uv Visible

This paper describes the synthesis and characterization of NiMgOH-rGO nanocomposites made using a chemical co-precipitation technique with various reducing agents (e.g., NaOH and NH4OH) and reduced graphene oxide at 0.5, 1, and 1.5 percent by weight. UV-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, a particle size analyzer, and cyclic voltammetry were used to characterize the composite materials. The formation of the NiMgOH-rGO nanocomposite with crystallite sizes in the range of 10–40 nm was inferred by X-ray diffraction patterns of materials, which suggested interlayers of Ni(OH)2 and Mg(OH)2. The interactions between the molecules were detected using Fourier-transform infrared spectroscopy, while optical properties were studied using UV-visible spectroscopy. A uniform average particle size distribution in the range of 1–100 nm was confirmed by the particle size analyzer. Using cyclic voltammetry and galvanostatic charge/discharge measurements in a 6 M KOH solution, the electrochemical execution of NiMgOH-rGO nanocomposites was investigated. At a 1 A/g current density, the NiMgOH-rGO nanocomposites prepared with NH4OH as a reducing agent had a higher specific capacitance of 1977 F/g. The electrochemical studies confirmed that combining rGO with NiMgOH increased conductivity.

scholarly journals Synthesis of Titanium Dioxide/Silicon Dioxide from Beach Sand as Photocatalyst for Cr and Pb Remediation

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1248
Author(s):  
Diana Rakhmawaty Eddy ◽  
Soraya Nur Ishmah ◽  
Muhamad Diki Permana ◽  
M. Lutfi Firdaus
Keyword(s):  
Particle Size ◽  
Solvothermal Method ◽  
Chemical Interaction ◽  
Amorphous Structure ◽  
Beach Sand ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
X Ray ◽  
Particle Size Analyzer ◽  
The Relationship

Heavy metals are non-biodegradable and have a high toxicity effect on microorganisms which makes their presence in the environment extremely dangerous. The method of handling heavy metal waste by photocatalysis techniques using TiO2/SiO2 composite showed a good performance in reducing harmful pollutants. In this study, SiO2 from Bengkulu beach sand, Indonesia, was used as a support material for TiO2 photocatalyst to remove Cr(VI) and Pb(II). SiO2 was obtained through leaching techniques using NaOH as a solvent. The TiO2/SiO2 composite photocatalyst was synthesized using a solvothermal method at 130 °C and then characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and a particle size analyzer (PSA). Based on the XRD diffractogram, the synthesized TiO2 showed the anatase structure while the SiO2 showed the amorphous structure. The Ti–O–Si bond is defined in the infrared (IR) spectra, which indicates that the relationship between TiO2 and SiO2 is a chemical interaction. The results of SEM and PSA characterizations show agglomerated spherical (round) particles with a mean particle size of 616.9 nm. The TiO2/SiO2 composite of 7:1 ratio showed the highest photocatalytic activity after 180 min of ultraviolet (UV) irradiation, with a concentration-decrease percentage of 93.77% and 93.55% for Cr(VI) and Pb(II), respectively.

scholarly journals Effect of Particle Size and Sintering Temperature on the Formation of Mullite from Kyanite and Aluminum Mixtures

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
F. R. Barrientos-Hernández ◽  
M. Pérez-Labra ◽  
A. Lobo-Guerrero ◽  
M. Reyes-Pérez ◽  
J. C. Juárez-Tapia ◽  
...  
Keyword(s):  
Particle Size ◽  
Open Porosity ◽  
Sintering Temperature ◽  
Thermal Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Free Silica ◽  
Effect Of Particle Size ◽  
Α Al2o3 ◽  
Ray Patterns

The effect of particle size and sintering temperature of the mixtures of kyanite and metallic aluminum related to the thermal transformation of kyanite into primary mullite and free silica was studied. In addition, the reaction between α-Al2O3 (in situ produced by aluminum oxidation) and the silica was obtained in cristobalite structure from kyanite to obtain secondary mullite. The kyanite powders were milled by 0.5, 3, 6, and 12 hours and then were mixed with aluminum powder, which were previously milled by 3 hours. After that, the powders were characterized by X-ray diffraction technique (XRD), scanning electronic microscopy (SEM), differential thermal analysis (DTA), and thermogravimetric analysis (TGA), and the particle size was determined in a centrifugal analyzer particle size Shimadzu model SA-CP4. The mixed powders were pressed uniaxially into cylindrical samples (compacts), and then sintering was conducted at 1100, 1200, 1300, 1400, 1500, and 1600°C; these samples were characterized by XRD, SEM, and thermodilatometry analysis (TD); density and open porosity measurements were performed by the Archimedes method. The samples were thermally etched to observe the microstructure, which consisted of mullite equiaxial grains contained in a glassy phase. It was observed that the nonmilled kyanite mineral becomes into mullite plus silica at temperatures between 1400 and 1500°C. When the particle size was reduced at sizes less than 1 µm, the transformation temperature was low until 200°C; the X-ray patterns of the sintered samples at 1400°C, ground for 6 hours, showed mullite peaks with small reflections of cristobalite and α-Al2O3, and these samples exhibited high density and low open porosity.

Fabrication of Monolithic UAl2 Pellet for High-Density Nuclear Fuel

2007 ◽  
Vol 26-28 ◽  
pp. 925-928 ◽  
Author(s):  
Ki Hwan Kim ◽  
Jong Man Park ◽  
Don Bae Lee ◽  
Chul Goo Chi ◽  
Chang Kyu Kim
Keyword(s):  
Particle Size ◽  
Average Diameter ◽  
The Other ◽  
Metallurgical Process ◽  
X Ray Diffraction ◽  
Atomization Process ◽  
X Ray ◽  
Advanced Fuels ◽  
Powder Metallurgical Process ◽  
Al Powder

Uranium powder, which can be obtained by the atomization process, was used to fabricate UAl2 by using powder metallurgy technology. Uranium powder and Al powder were blended, extruded, and annealed into a UAl2 rod in a mold. Sound UAl2 rods were fabricated by the powder metallurgical process. The relative density of the UAl2 pellet formed by an annealing was at about 94%. The density increased with higher constraints on the mold and a smaller particle size of the uranium powder. A coarse uranium powder of about 80 μm in average diameter represented the remaining un-reacted uranium phase. On the other hand, a fine uranium powder of about 50 μm in average diameter could achieve a pure UAl2 phase without a uranium phase. The analysis by an X-ray diffraction pattern confirmed that the annealed specimens had interacted to form a UAl2 phase. Conclusively, the sintered UAl2 pellet is expected to be useful in developing advanced fuels.

Fabrication of Flake-Shaped Core-Shell Micro Particles by Way of Thermal Decomposition of Pentacarbonyl Iron on Diatomite Surface

2011 ◽  
Vol 194-196 ◽  
pp. 730-733 ◽  
Author(s):  
Wen Qiang Zhang ◽  
De Yuan Zhang ◽  
Jun Cai
Keyword(s):  
Thermal Decomposition ◽  
Chemical Composition ◽  
Average Diameter ◽  
Core Shell ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Particles ◽  
Average Aspect Ratio ◽  
Main Chemical Composition

In order to fabricate flake-shaped core-shell micro particles (FCMP) with light weight efficiently, deposition on diatomite was carried out by thermal decomposition. The deposition of Fe on diatomite was accomplished by thermal decomposition of pentacarbonyl iron (Fe(CO)5). The scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD) are used to make clear their morphology microstructure, chemical composition, and crystal structure. The average diameter of FCMP is around 40μm, and the average aspect ratio is over 15. The main chemical composition of the FCMP is Fe, Si, Oand C. The XRD result revealed that crystal structures of the FCMP is close to α-Fe. The vibrant sample magnetometer (VSM) result revealed that the FCMP belong to soft magnetic material. The density test results show that the density of FCMP is close to the 2.6, which is lower than the density of pure carbonyl iron powder.

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