Effects of Reactant Mixing Mode on Dispersibility and Particle Size Stability of Cuprous Oxide Particles

2012 ◽  
Vol 27 (2) ◽  
pp. 195-200
Author(s):  
Yue-Jun WANG ◽  
Kang-Gen ZHOU ◽  
Zhi-Gang JIANG
Keyword(s):  
Particle Size ◽  
Cuprous Oxide ◽  
Size Stability ◽  
Oxide Particles

Study of the microstructure and particles of vanadium (III) oxide, vanadium (V) oxide and lithium aluminate powders

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Vanadium Oxide ◽  
Size Distribution ◽  
Microstructural Analysis ◽  
Coherent Scattering ◽  
Powder Materials ◽  
Lithium Aluminate ◽  
Range Limit ◽  
Oxide Particles

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.

Tunable morphologies of polymer capsules templated from cuprous oxide particles for control over cell association

2020 ◽  
Vol 31 (2) ◽  
pp. 505-508 ◽  
Author(s):  
Hongyan Pei ◽  
Yanyan Bai ◽  
Jianman Guo ◽  
Zhiliang Gao ◽  
Qiong Dai ◽  
...  
Keyword(s):  
Cuprous Oxide ◽  
Cell Association ◽  
Oxide Particles

Effect of segregation on particle size stability and SPS sintering of Li2O-Doped magnesium aluminate spinel

2019 ◽  
Vol 39 (10) ◽  
pp. 3213-3220 ◽  
Author(s):  
L.B. Caliman ◽  
D. Muche ◽  
A. Silva ◽  
C.A. Ospina R. ◽  
I.F. Machado ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Size Stability ◽  
Sps Sintering

scholarly journals Synthesis of High-Purity Silica Nanoparticles by Sol-Gel Method

2017 ◽  
Vol 19 (4) ◽  
pp. 295 ◽  
Author(s):  
S.V. Lazareva ◽  
N.V. Shikina ◽  
L.E. Tatarova ◽  
Z.R. Ismagilov
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Sio2 Content ◽  
Reaction Conditions ◽  
Minimum Particle Size ◽  
Size Stability ◽  
Different Temperatures ◽  
Acid Catalyzed ◽  
Silica Sols ◽  
Hydrolysis Of

Colloidal silica (silica sol) nanoparticles were synthesized by ammonia- and hydrochloric acid-catalyzed hydrolysis of tetraethoxysilane with subsequent condensation and polymerization. Silica particles with the size of 12‒160 nm were obtained at different temperatures and ratios of the initial reactants and studied by means of TEM, AFM, IR spectroscopy and zeta-potential measurements. The reaction conditions providing the minimum particle size in the final product of the most complete hydrolysis were determined. At pH above 8.5, an increase in the SiO2 content of the sol to 23 wt.% did not change the particle size. At a low (~ 1.8 wt.%) SiO2 content of the sol, a wide variation in pH also did not exert a significant effect on the particle size. Stability of the silica sols synthesized in an alkaline medium was enhanced by the replacement of alcohol with water during evaporation at pH 8.5‒9.5. The possibility to produce silica sols with the required characteristics (particle size, pH, stability, purity, and SiO2 content in an aqueous or alcohol medium) makes them applicable in various industries.

scholarly journals On the Role of Stirring on Microstructure and Ductility of Rheocast Al Alloys

JOM ◽  
2021 ◽  
Author(s):  
Qing Zhang ◽  
Stefan Jonsson ◽  
Anders E. W. Jarfors
Keyword(s):  
Particle Size ◽  
Fracture Surface ◽  
Oxide Films ◽  
Al Alloys ◽  
Combined Effect ◽  
Liquid Feeding ◽  
Oxide Particles ◽  
Large Clusters ◽  
Mg Content

AbstractTwo alloys containing different Mg contents have been used to study the combined effect of stirring and oxidation on microstructure and ductility. The results show that intensive stirring can sufficiently disperse the α-Al particles and enable better liquid feeding during solidification and consequently reduce the porosity. The morphology of the oxides is determined by the amount of both Mg and stirring. With lower Mg content, the oxides present as oxide films, which can be broken up during stirring. In alloy with higher Mg content, the oxides exist as particles with numerous cracks, and the particle size increases slightly after stirring. In the Magsimal 59 alloy, due to the presence of large clusters of pores in the fracture surface, the influence of the small oxide particles on the ductility is negligible. In contrast, in the 42000 alloy, large oxide films on the fracture surface are correlated with the ductility.

Excessive ThO2 Particle Growth in Ni-2ThO2 at High Temperature

1970 ◽  
Vol 28 ◽  
pp. 416-417
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
Particle Size ◽  
Metal Matrix ◽  
Oxide Dispersion Strengthened ◽  
Particle Growth ◽  
Interparticle Spacing ◽  
Refractory Oxide ◽  
Oxide Dispersion ◽  
Volume Percent ◽  
Oxide Particles ◽  
Cold Worked

It is generally accepted that a uniform spatial distribution of fine refractory oxide particles is required in an oxide-dispersion-strengthened metal to provide good elevated-temperature strengths. The presence of these particles stabilizes the cold-worked microstructure by anchoring low-angle cell boundaries and by restricting the motion of dislocations during loading. Such action by the particles must be a function of the interparticle spacing as is proposed by the Orowan model for yield stress. For a given volume percent of oxide in the metal matrix, the interparticle spacing is directly proportional to the particle size. Therefore, particle growth during the processing of oxide-dispersion-strengthened metals increases the interparticle spacing and inherently decreases the strength.

Morphology Change in Cuprous Oxide Particle Synthesis with PVP: Effect of Reaction Temperature

2013 ◽  
Vol 873 ◽  
pp. 147-151
Author(s):  
Cheng Dong Wang ◽  
Ji Qian Wang
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Surface Energy ◽  
Reaction Temperature ◽  
Cuprous Oxide ◽  
Oxide Particle ◽  
High Energy ◽  
Red Shift ◽  
Reaction Condition ◽  
Lower Temperature

Cuprous oxides with different morphologies could be prepared by simply changing the reaction condition, such as the temperature. Here, we report the Cu2O morphological transforming from polyhedron to cube with the reaction temperature increasing from 35C to 65C. At lower temperature, the polyvinylpyrrolidone (PVP) working as a crystal modifier which decreases the surface energy of facets (111) and (110), thus these high energy facets appear in relative low temperature. Facets (111) and (110) gradually diminished along with temperature increasing, while facet (100) expanded. The morphology became into cube from polyhedron. Cu2O particles synthesized at 65C are larger than those at 35C. The UV-Vis extinction bands of the cuprous oxide synthesized in this research were red-shift with the increase of particle size.

Formation mechanism of spherical oxide particles containing dye

1999 ◽  
Vol 14 (5) ◽  
pp. 2088-2091
Author(s):  
Sixin Wu ◽  
Congshan Zhu
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Formation Mechanism ◽  
Isoelectric Point ◽  
Sol Gel ◽  
Diameter Distribution ◽  
Maximum Particle Size ◽  
Maximum Particle ◽  
Oxide Particles ◽  
Positively Charged

2-[3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidine)-1-propenyl]-1,3,3-trimethyl-3H-indolium idoide (HICI) dye-doped SiO2 particles were synthesized by sol-gel method. Dimension, diameter, distribution, and homogeneity of the particles are closely related to the positively charged dye concentration, corresponding to the zeta potential of the particles. When the dye concentration reaches about 7.8 × 10−4 mol/mol SiO2, corresponding to the isoelectric point of the particles, the maximum particle size and the most homogeneity can be reached.

Magnetic behavior of coated superparamagnetic iron oxide nanoparticles in ferrofluids

2001 ◽  
Vol 676 ◽  
Author(s):  
W. Voit ◽  
D. K. Kim ◽  
W. Zapka ◽  
M. Muhammed ◽  
K. V. Rao
Keyword(s):  
Particle Size ◽  
Iron Oxide ◽  
Superparamagnetic Iron Oxide ◽  
Magnetic Behavior ◽  
Blocking Temperature ◽  
Iron Oxide Particles ◽  
Physical Particle ◽  
Superparamagnetic Iron Oxide Particles ◽  
Oxide Particles ◽  
Co Precipitation

ABSTRACTWe present a study on the magnetic behavior of nanosized iron oxide particles coated with different surfactants (sodium oleate, PVA and starch) in a ferrofluid. The effect of the coating material, and different particle concentrations in the ferrofluid have been magnetically investigated to determine the effective magnetic particle size and possible interaction. The superparamagnetic iron oxide particles, synthesized by a controlled co-precipitation technique, are found to contain magnetite (Fe3O4) as a main phase with a narrow physical particle size distribution between 6 and 8 nm. The mean effective magnetic size of the particles in different ferrofluid systems are estimated to be around 4-5 nm which is smaller than the physical particle size. On a 10% dilution in the starch coated ferrofluid we observe a decrease in the blocking temperature.

Colloidal Crystal Templates Direct the Morphologies of Fabricated Porous Cuprous Oxide Particles

2014 ◽  
Vol 26 (10) ◽  
pp. 3084-3088 ◽  
Author(s):  
Ming Fu ◽  
Ailun Zhao ◽  
Dawei He ◽  
Yongsheng Wang
Keyword(s):  
Cuprous Oxide ◽  
Colloidal Crystal ◽  
Oxide Particles
Sign in / Sign up

Export Citation Format

Share Document