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

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.

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Modeling the Production Technology of Fully-Pressed Bi-Metal Powder Materials and Products

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.316.570 ◽

2021 ◽

Vol 316 ◽

pp. 570-575

Author(s):

Badrudin G. Gasanov ◽

Abakar B. Gasanov ◽

Artem A. Aganov

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Bulk Density ◽

Size Distribution ◽

Metal Powder ◽

Production Technology ◽

Powder Mixture ◽

Geometric Parameters ◽

Powder Materials ◽

Loading Devices

The features of calculating the thickness of the layers of bimetallic powder products without holes and the type of bushings are shown. The effect of the particle size distribution of the powders, the kinematic and geometric parameters of the loading devices and molds on the mechanism of the expiration of the powder mixture and on the thickness of the layers of the molded product is studied. A technique has been developed for determining the dimensions of the feeder cassette and tooling, depending on the overall dimensions and thicknesses of the working layers, in the production of whole-pressed bimetallic products on press machines with a vertical arrangement of layers. It was found that the thickness of each layer of bimetallic products depends on the geometric parameters of the feeder cassette and tooling, bulk density, particle size distribution and other characteristics of the powders, as well as on the speed of lowering the lower punch ν1 .

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CATALYTIC ACTIVITY OF VANADIUM OXIDE DOPED WITH PALLADIUM NANOPARTICLES ON OXIDATION OF 5-HYDROXYMETHYLFURFURAL

ASEAN Engineering Journal ◽

10.11113/aej.v10.16593 ◽

2021 ◽

Vol 10 (2) ◽

Author(s):

Settakorn Upasen ◽

Patiparn Boonruam ◽

Joongjai Panpranot ◽

Soipatta Soisuwan ◽

Piyasan Praserthdam

Keyword(s):

Particle Size ◽

Catalytic Activity ◽

Particle Size Distribution ◽

Vanadium Oxide ◽

Size Distribution ◽

Palladium Nanoparticles ◽

Heterogeneous Catalysts ◽

Chemical Reduction ◽

Synergic Effect ◽

V2o5 Catalysts

2,5-Furan dicarboxylic acid (FDCA) is a bio-based chemical used as a feedstock for a wide range of industrial applications - particularly the bioplastic industries. It is derived from 5-hydroxymethylfurfural (HMF) through a reaction of oxidation using either homogeneous or heterogeneous catalysts. According to the advantages of heterogeneous catalysts, this research aims to seek a novel catalyst type with high selectivity and high activity. We performed an investigation of the synergic effect of palladium nanoparticles and V2O5 catalysts on catalytic oxidation of HMF and physicochemical properties. A commercial vanadium oxide powder (V2O5) was doped with 1 wt.% palladium nanoparticles (Pd NPs). The Pd NPs were prepared by the colloid-chemical reduction method. Two different synthesis processes were performed base on the consequence of the combination of colloid-chemical reduction and immobilization steps, herein stepwise (ST) and simultaneous (SI) process. For the ST process, Pd NPs were reduced and then immobilized on V2O5 powder. During the SI process, the reduction and immobilization steps took place simultaneously. Physical and chemical properties of a prepared catalyst such as morphology, particle size distribution, and chemical structure and composition were characterized using various techniques, e.g. TEM, BET, X-ray diffraction, UV-vis spectrophotometer. It was distinctly found the synergic effect between Pd NPs and V2O5 catalysts on the surface catalytic activity of HMF oxidation and catalytic selectivity. The Pd NPs incorporated catalysts (ST and SI processes) gave catalytic activity at 63%, which are 2-fold in catalytic activity in comparison with bare V2O5 catalysts as well as they were selective to FDCA up to 19-24%. The step of catalyst preparation slightly influenced on catalytic activity and yield of FDCA; however, it did alter particle size distribution of Pd NPs and surface characteristics

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Precision measurements of the particle size distribution of powder materials based on state primary standard for the units of disperse parameters of aerosols, suspensions and powder materials GET-163

Journal of Physics Conference Series ◽

10.1088/1742-6596/1134/1/012037 ◽

2018 ◽

Vol 1134 ◽

pp. 012037

Author(s):

T M Magomedov ◽

D I Belenkii

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Primary Standard ◽

Precision Measurements ◽

State Primary Standard ◽

Powder Materials

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Preparation and Charactorization of Superfine YAG Powder Materials via the Co-Precipitation Methods

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.164.162 ◽

2012 ◽

Vol 164 ◽

pp. 162-165 ◽

Cited By ~ 1

Author(s):

Jie Guang Song ◽

Ai Xia Chen ◽

Qiang Li ◽

Zhi Wen Qiu ◽

Jian Feng Zhou ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Functional Materials ◽

Distribution Range ◽

Precipitation Method ◽

Sintering Behavior ◽

Powder Materials ◽

Co Precipitation

YAG is widely applied as the structure materials and the functional materials because of some excellent performances in the chemistry. The pure superfine YAG powder materials are prepared via the co-precipitation method after calcining the precursor of YAG at 1100°C. The superfine YAG powders has the better dispersion, the particle size distribution range is narrow bewteen 200 and 350nm. The superfine YAG mainly show near-spherical, and partly sintering behavior among the particles.

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