Synthesis of Uniform Spherical Alumina Powders by Homogeneous Precipitation

2013 ◽  
Vol 341-342 ◽  
pp. 100-104
Author(s):  
Xiao Juan Xu ◽  
Xu Dong Sun ◽  
Ya Qiu Liang ◽  
Wei Qiu
Keyword(s):  
Ammonium Sulfate ◽  
Aluminum Nitrate ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Homogeneous Precipitation ◽  
Homogeneous Precipitation Method ◽  
Alumina Particles ◽  
Precursor Powders ◽  
Spherical Alumina

Uniform spherical alumina powders have been synthesized via homogeneous precipitation method from aluminum nitrate using urea as the precipitant. The amount of ammonium sulfate has a significant effect on morphology and particle size of the precursor powders. It was found that spherical particles can be obtained when the molar ratio of ammonium sulfate to aluminum nitrate is about 0.72 and the concentration of the aluminum nitrate is 0.005M. Spherical alumina particles with 400 nm in diameter were obtained by calcining the precursors at 1100°C for 4 hrs.

Synthesis of Ultrafine Spherical Yttrium Aluminum Garnet Powders from Yttrium Nitrate and Aluminum Nitrate System

2013 ◽  
Vol 377 ◽  
pp. 151-155
Author(s):  
Xiao Juan Xu ◽  
Xu Dong Sun ◽  
Ji Guang Li ◽  
Xiao Dong Li ◽  
Di Huo ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Yttrium Aluminum Garnet ◽  
Aluminum Nitrate ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Yttrium Nitrate ◽  
Metallic Ions ◽  
Yttrium Aluminum ◽  
Ft Ir ◽  
Precursor Powders

Ultrafine spherical yttrium aluminum garnet (YAG) powders have been synthesized via homogeneous precipitation method using urea as the precipitant. The precursor powders were calcinated at 1000°C or 1100°C for 4 hrs and then were studied by means of FE-SEM, XRD, FT-IR and TG-DTA. The result shows that the amount of ammonium sulfate has a significant effect on morphology and particle size of powders. Pure phase and spherical YAG particles with 350 nm in diameter can be obtained when the molar ratio of ammonium sulfate to aluminum nitrate is about 0.75 and the concentration of the metallic ions is 0.008M.

Process Optimization and Preparation of Ferric Oxide Nanoparticles by Homogeneous Precipitation Method

2013 ◽  
Vol 401-403 ◽  
pp. 683-687
Author(s):  
Jie Feng Ding ◽  
Jian Fen Li ◽  
Wei Yi Dan ◽  
Qiang Sheng Wang ◽  
Han Fen Zhou
Keyword(s):  
Biomass Gasification ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Reaction ◽  
Homogeneous Precipitation ◽  
Optimal Conditions ◽  
Iron Salt ◽  
Fine Crystal ◽  
Technical Parameters ◽  
Homogeneous Precipitation Method

For the purpose of developing an effective Fe2O3-doped nickel-based catalysts to be used in biomass gasification, Fe2O3nanoparticles were prepared by homogeneous precipitation method involving an aqueous solution of Fe (NO3)3·9H2O and urea as precipitator. Different approaches, such as XRD and SEM, were used to characterize the products. Meanwhile, the effects of various technical parameters in preparation process on the yield of products were investigated, and optimal conditions for preparing Fe2O3nanoparticles were found as follows: the molar ratio of urea to Fe (NO3)3·9H2O for 5:1, temperature of precipitation reaction for 125°C, concentration of iron salt for 0.20mol/L. The Fe2O3nanoparticles prepared under the optimal conditions were spherical in shape and well dispersed; they had high purity and a fine crystal phase of cubic syngony with a mean particle size of about 28nm.

Synthesis and Characterization of Uniform Zirconia Particles by Homogeneous Precipitation Method

2013 ◽  
Vol 32 (4) ◽  
pp. 391-395 ◽  
Author(s):  
Khalida Akhtar ◽  
Ikram Ul Haq ◽  
Uzma Hira
Keyword(s):  
Steel Substrate ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Sem Images ◽  
Experimental Conditions ◽  
Homogeneous Precipitation Method ◽  
Size Uniformity ◽  
Ft Ir ◽  
Micrometer Size

AbstractColloidal spherical particles (micrometer size) of zirconia were synthesized at 50°C by homogeneous precipitation method from aqueous solutions, containing appropriate amounts of zirconium chloride, hydrochloric acid, potassium sulphate and urea. Results revealed that reactants concentration significantly affected characteristics of the precipitated solids, which ranged from gel to dispersion of discrete particles. Size uniformity in the resulted particles was obtained only under limited conditions. SEM images revealed that particles of zirconia obtained under the described experimental conditions have spherical morphology, which maintained their original shape after calcination at 700°C. Selected powders were also characterized with XRD, TGA/DTA, and FT-IR techniques. XRD results showed that as-prepared and calcined powders were crystalline. We believe that our method is simple and has the potential for further tailoring of the particles characteristics. Work is in progress in our laboratory in developing Cu-ZrO2 metal matrix composite coating on steel substrate with better resistant properties than simple Cu electroplating.

Luminescence Properties of Europium-Doped Yttrium Oxides Derived from Their Dodecylsulfate-Templated Mesostructure and Nanotube Forms

2003 ◽  
Vol 775 ◽  
Author(s):  
Tsuyoshi Kijima ◽  
Kenichi Iwanaga ◽  
Tomomi Hamasuna ◽  
Shinji Mohri ◽  
Mitsunori Yada ◽  
...  
Keyword(s):  
Room Temperature ◽  
Broad Band ◽  
Concentration Quenching ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Bulk Materials ◽  
Main Band ◽  
Homogeneous Precipitation Method ◽  
Order Of Magnitude ◽  
Weak Luminescence

AbstractEuropium-doped hexagonal-mesostructured and nanotubular yttrium oxides templated by dodecylsulfate species as well as surfactant free bulk oxides were synthesized by the homogeneous precipitation method. All the as grown nanostructured or bulk materials with amorphous or poorly crystalline frameworks showed weak luminescence bands at room temperature. On calcination at 1000°C these materials were converted into highly crystalline yttrium oxides, resulting in a total increase in intensity of all the bands by one order of magnitude. In the hexagonal-mesostructured system, the main band due to the 5D0-7F2 transition for the calcined phases showed a sharp but asymmetrical multiplet splitting indicating multiple Eu sites. Concentration quenching was found at a Eu content of 3 mol% or above for these phases. In contrast, the main emission for the calcined solids in the nanotubular system occurred as poorly resolved broad band and the intensity of the main band at higher Eu content was significantly enhanced compared with those for the other two systems.

Preparation of α-Ni(OH)2 with Flowerlike Hierarchical Architectures via Homogeneous Precipitation Method

2011 ◽  
Vol 284-286 ◽  
pp. 684-687
Author(s):  
Chang Yu Li ◽  
Li Li Liu ◽  
Shou Xin Liu
Keyword(s):  
Electron Microscopy ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Α Phase ◽  
Transmission Electron ◽  
Hierarchical Architectures ◽  
Flowerlike Structure ◽  
Adsorption Desorption

Without using any templates or surfactants, flowerlike α-nickel hydroxide (Ni(OH)2) was successfully synthesized by homogeneous precipitation method. The prepared products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption. The prepared Ni(OH)2 is α-phase with specific surface area of 245.0 m2/g and shows flowerlike structure with 4-6 um in diameter.

Syntheses of ultra-fine barium carbonate powders by homogeneous precipitation method

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Guo Chen ◽  
Jin Chen ◽  
Jinhui Peng
Keyword(s):  
Barium Carbonate ◽  
Barium Chloride ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Chloride Dihydrate ◽  
Homogeneous Precipitation Method

AbstractUltra-fine barium carbonate powders were successfully synthesized using barium chloride dihydrate (BaCl

Effect of surfactants on synthesis of TiO2 nano-particles by homogeneous precipitation method

2008 ◽  
Vol 188 (1) ◽  
pp. 52-54 ◽  
Author(s):  
Hui Wang ◽  
Pingan Liu ◽  
Xiaosu Cheng ◽  
Anze Shui ◽  
Lingke Zeng
Keyword(s):  
Nano Particles ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Homogeneous Precipitation Method

Preparation of Fine Ag2WO4 Antibacterial Powders and Its Application in the Sanitary Ceramics

2011 ◽  
Vol 284-286 ◽  
pp. 1321-1325 ◽  
Author(s):  
Qian Ping Wang ◽  
Xiang Xiong Guo ◽  
Wei Hua Wu ◽  
Shu Xian Liu
Keyword(s):  
Antibacterial Activities ◽  
Antimicrobial Action ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Antibacterial Mechanism ◽  
Homogeneous Precipitation Method ◽  
Bactericidal Effects

Superfine Ag2WO4 antibacterial powders, which are prepared by supersonic assisted homogeneous precipitation method, is added 1.0-1.5wt.% to sanitary ceramics, having 90% antimicrobial action, and achieve good bactericidal effects. The antibacterial ceramics with Ag2WO4 were soaked into acid and alkali for 3 months, and antibacterial activities had little change, keeping good antimicrobial durability. Finally, the antibacterial mechanism of Ag2WO4 ceramics is advanced.

Enhanced adsorption removal of methyl orange from aqueous solution by nanostructured proton-containing δ-MnO2

2015 ◽  
Vol 3 (10) ◽  
pp. 5674-5682 ◽  
Author(s):  
Yan Liu ◽  
Chao Luo ◽  
Jian Sun ◽  
Haizhen Li ◽  
Zebin Sun ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Solid State ◽  
Solid State Reaction ◽  
Proton Exchange ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Adsorption Removal ◽  
Homogeneous Precipitation Method ◽  
Enhanced Adsorption

Two nanostructured proton-containing δ-MnO2 (H-δ-MnO2) materials were synthesized through proton exchange for K-containing δ-MnO2 (K-δ-MnO2) nanosheets and nanoparticles prepared by the hydrothermal homogeneous precipitation method and solid-state reaction.

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