Kashapov R.N.

Candidate of Engineering Sciences (Ph.D.), Leading Research Officer, Kazan (Volga Region) Federal University, Department of “Biomedical Engineering and Innovation Management”, Research Laboratory of Plasma Chemical Production of Functional Materials, Russia

Plasma electrolyte production of titanium oxide powder

https://doi.org/10.58224/2618-7183-2022-5-6-75-84
Abstract
The work is devoted to the research of plasma-electrolyte process realized in conditions of cathodic polarity of active metal electrode and its immersion into electrolyte to produce titanium oxide micro- and nanoparticles as well as titanium oxide-coated particles up to 10 μm in size. Two modes of discharge combustion differing in heat generation and concentration of electrolyte solution on particle size distribution were found to influence. Voltage increase can result in discharge combustion in arc mode due to thermal emission of electrons and intensive heating of titanium cathode. This, in its turn, leads to formation of titanium particles up to 10 μm in size, which surface is oxidized. It was found that discharge combustion in the regime with less heat emission leads to formation of titanium oxide particles sized less than 1 µm. These powders can be used in additive manufacturing, powder metal-lurgy and as additives in composite materials.
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Structure and analysis of amorphous silicon dioxide nanoparticles

https://doi.org/10.58224/2618-7183-2022-5-6-85-94
Abstract
One of the most common methods of studying as well as controlling the environment and production products is the method of chromatography. The main working element that separates components into components, in particular, is silicon dioxide powder of nano and micro sizes. At the same time powder materials are widely used and relevant for powder technologies of additive construction. The aim of the work is to study the structure and analysis of obtained nanoparticles of amorphous silicon dioxide, satisfying the characteristics for use in high-performance liquid chromatography columns, as well as in various additive technologies. Studies have shown that the method of introducing water vapor in the plasma chemical reactor of the installation for the production of amorphous silica significantly affects the presence of free hydroxyl groups. In the infrared spectrum of the product, which was caught at a distance of 2 meters the line 3750 cm-1 is absent. At a distance of 1 meter the intensity of the line as a reference with 100% value. When a small amount of NaCl was added to the briquette used in spraying, the intensity dropped by 50%. When removed 1.5 meters away, the intensity is 75%. It follows that in the hotter gas during rapid cooling more OH hydroxyl groups are formed on the surface of the aggregates, when moving away from the reactor i.e. cooling the outgoing gas OH groups are formed less.
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Study of the plasma-electrolyte process for producing titanium oxide nanoparticles

https://doi.org/10.58224/2618-7183-2022-5-5-70-79
Abstract
The work is devoted to the investigation of the process of obtaining titanium oxide nanoparticles by burning high voltage DC gas discharge in an argon atmosphere when an aqueous solution is used as one of the electrodes. It was found that using an aqueous glycine solution in an inert gas medium, the plasma-electrolyte process using a streamer discharge is well suited for producing titanium oxide nanoparticles. An important regularity of particle size decrease with the increase of argon pressure in the chamber was revealed. Thus, when the pressure is increased from 1 MPa to 3 MPa, a sharp decrease in the average particle size from 62 nm to 16 nm is observed, while the changes in the aver-age particle size are not cardinal already in the process of pressure increase up to 5 MPa. A narrowing of the dispersion composition scatter with increasing pressure for 1 MPa - ± 40 nm, 3 MPa - ± 20 nm and 5 MPa - ± 8 nm was determined. The presence of titanium oxide particles was confirmed on the basis of plasmon resonance detection at 224, 230 and 235 nm.
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Development of a plasma-chemical method for producing amorphous silicon dioxide nanoparticles

https://doi.org/10.58224/2618-7183-2022-5-5-80-90
Abstract
One of the most promising areas of production is additive technologies of building, in particular powder 3D printing. The aim of the work is to create a plasma-chemical method of obtaining amorphous silicon dioxide, satisfying the characteristics for the use of additive technologies of build-ing products, as well as in columns used in high performance liquid chromatography - one of the most common methods of study, as well as control of the environment and production products. One of the main requirements for particles is a porous structure with a surface that has a chemically bonded or physically coated active phase used for separation. Experimental installation for obtaining amorphous silica was developed, the feature of which was the possibility of rapid and continuous supply of pressed briquettes, rather than powdered material as it was previously. Studies have shown that the developed plasma-chemical process implemented in the condition of evaporation of briquettes consist-ing of 70% sand and 30% coke is effective enough to produce silicon oxide nanoparticles smaller than 200 nm. The developed method of obtaining nanoparticles should be further investigated on the ability to obtain nanoparticles smaller than 20 nm, it is so necessary to obtain the specific surface area of 200 m2/g, which will make it possible to produce from this raw material particles of the fixed phase carrier column of high-performance liquid chromatography.
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