Composite material c/al2o3 and method of its obtaining
SUBSTANCE: uniform, continuous and dense layer of pyrolytic carbon has width of carbon coating, close to monolayer coating, equal 0.4-0.5 nm, density of precipitated carbon coating, equal ρC = 2.0-2.1 g/cm3, specific surface SBET = 90-200 m2/g, cumulative volume of pores ΣVpore≤0.4 cm3/g, average size of pores DBET≤10 nm, most probable size of pores DBJH = 5-7 nm with absence of micro pores. Invention also relates to method of production of such mesoporous composite material.
EFFECT: claimed mesoporous composite material has high-quality thin carbon coating, which totally and uniformly covers external surface and walls of pores of said material.
4 cl, 3 dwg, 3 tbl, 10 ex
The invention relates to the preparation of mesoporous carbon composite materials with high quality carbon coating. To mesoporous carbon composite materials include materials which are mesoporous matrix, the outer surface and pore walls of which are covered with a thin continuous layer of carbon.
Carbon materials (MIND) is attracting increasing attention as a promising sorbents and carriers for commercial metal catalysts. They have some unique properties, such as chemically inert nature of the surface in combination with the easily controlled functionalization, the weak interaction between the metal carrier, good electrical and thermal conductivity. However, the extent of their use is limited by the fact that: (1) most commercially available carbon materials are microporous, which prevents their use in reactions involving large molecules (mesoporous structure greatly facilitates nutrititional transfer); (2) the most famous MINDS have low mechanical strength and susceptibility to abrasion or small surface.
In order to make good use of the properties of carbon materials, has been suggested obvious, however demanding approach, the Idea is to synthesize a composite material in which the external and the internal surface of the mesoporous matrix besieged thin continuous layer of pyrolytic carbon. As a matrix for the creation of carbon-containing composites can be used, for example, oxides of metals: Al2O3, SiO2, MgO, CaO, TiO2(M. Inagaki Carbon coating for enhancing the functionalities of materials. Carbon 2012;50:3247-66). Aluminium oxide is of particular interest because it is the most widely used medium for commercial catalysts. Its main advantages are the ideal mechanical and thermal strength and mesoporous texture. The advantages of the MIND are their properties such as the absence of surface acidity, the non-polar nature of the surface, the weak interaction between the metal carrier, a relatively high conductivity. Composite material C/Al2O3able to inherit the best qualities of both aluminum oxide and carbon. All these properties are extremely useful for such applications C/Al2O3composite materials, such as active sorbents and carriers, metal-C/Al2O3catalytic compositions, etc., for example, Visser s JPR et al. (Carbon-covered alumina as a support for sulfide catalysts. J Catal 1988;114:291-302) used C/Al2O3polymers as carriers for cobalt-sulfide catalyst hydrodesulfurization with increased catalytic� activity. Misra Ch et al. US Patent 5093092(1992), US Patent 5270278(1993) reported about the unique properties of hybrid adsorbent C/Al2O3with a thin carbon coating to adsorb more organic impurities than the equivalent amount of activated carbon and oxalate ions, which are usually not adsorbed by the carbon. Rao et al. (US Patent 20060254989 A1, 2006) indicate a high antibacterial efficacy of silver nanoparticles deposited on carbon-coated Al2O3in the purification of drinking water.
According to published data, in C/Al2O3composites there is a coordinated interaction effect (synergistic effect) between the phases of aluminum oxide and carbon. This effect increases if the carbon completely covers a matrix of Al2O3thin and evenly distributed over the surface of the layer. Zheng MY, et al. (Carbon-covered alumina: A superior support of noble metal-like catalysts for hydrazine decomposition. Catal Lett 2008; 121(1-2):90-96) received significantly higher values of catalytic activity applied for carbides, nitrides and phosphides of molybdenum in the decomposition of hydrazine, if the composite C/Al2O3(prepared by the method of impregnation-pyrolysis) was used as the carrier instead of the usual Al2O3. If the carbon coating was less monosloevogo or, on the contrary, consisted of several layers, catalysts demonstrirov�and relatively low activity due to the strong interaction between the metal and the carrier or due to the low dispersion of the metal on the carrier, respectively. When monoclonal coating of aluminum oxide with carbon deposited catalysts showed the highest efficiency in the decomposition of hydrazine.
Currently there are two main methods of synthesis of composite materials C/Al2O3each of which has its advantages and disadvantages.
The first method is the synthesis of composites is carried out by two-stage scheme "impregnation-pyrolysis" (Lin L, et al. Uniformly Carbon-Covered Alumina and Its Surface Characteristics. Langmuir 2005; 21:5040-5046); MY Zheng et al. Carbon-covered alumina: A superior support of noble metal-like catalysts for hydrazine decomposition. Catal Lett 2008; 121 (1-2):90-96; Wang Y} et al. Delicately controlled synthesis of mesoporous carbon materials with thin pore walls. Acta Phys-Chim Sin 2011; 27:729-735). The advantage of this method is fairly uniform carbon layer on the surface of the matrix. The method consists in the fact that in the first stage matrix impregnert highly diluted solution of organic compounds, for example, cyclohexene series, sucrose, polyurethane, urea grafted 4,4-methylene-bis-(phenylisocyanate), etc. Obtained carbon-containing precursor is dried at 90-100°C, after which the second stage of the process it paralizuet at temperatures of 600-1200°C. the Cycles of impregnation-pyrolysis" is repeated until the desired carbon content in the composite material.
Multistage process "impregnation-pyrolysis" it is hardly possible to easily adaptirovat� to the production of high quality C/Al 2O3a commercial scale because of its complexity and the need for analysis of the carbon bed after each cycle to adjust the quality of the final composite.
The second approach to the synthesis of C/Al2O3composites based on the pyrolysis of light hydrocarbons on the surface of aluminum oxide at temperatures above 400 C (Youtsey KJ et al. US Patent 4018943 (1977); Butterworth SL, played by AW. Carbon-coated alumina as a catalyst support. 1. Preparation via liquid and vapor phase pyrolysis system. Appl Catal 1985;16:375-88; Vissers JPR et al. Carbon-covered alumina as a support for sulfide catalysts. J Catal 1988; 114:291-302; Misra Ch et al. US Patent 5093092(1992)). The process is carried out in flow-through mode, passing the mixture of hydrocarbon and inert gas through a turbulent layer of Al2O3. As carbon precursors used hydrocarbons such as ethylene, propylene, propane, propane-butane mixture, butadiene, hexane, benzene, ethyl benzene, cyclohexene, liquefied petroleum gas. According to the currently accepted terminology, the decomposition of hydrocarbon precursors on porous matrices is called chemical vapor infiltration (chemical vapor infiltration process, CVI). Alternatively, the deposition of carbon, which includes the gas-phase decomposition of the precursor on solid surfaces, called chemical vapor deposition (chemical vapor deposition, CVD) (P. Delhaes Review. Chemical vapor deposition and infiltration processes of carbon materials. Carbon 2002; 40:641-657); Li (A, Norinaga K et al. Modeling and simulation of materils synthesis: Chemical vapor deposition and infiltration of pyrolytic carbon. Compos Sci Technol 2008; 68:1097-1104).
The economic effect of preparation of composite materials by the method of CVI is obvious: the process is technologically simple (one-stage procedure), are used reagents available in sufficient quantities and at affordable prices. The disadvantage is that because of the very complicated mechanism of the process difficult task is to find conditions that ensure the high quality of the carbon coating.
Carbon coatings in mesoporous composites (C/Al2O3started to study back in the 80-ies mainly because of the need to improve the quality of adsorbents and carriers for commercial catalysts. Misra Ch et al. (US Patent 5270278 (1993) stated that "mostly" continuous monocline coating on the surface of aluminum oxide was obtained in the pyrolysis of propane or butadiene on the aluminum oxide surface with SBETH=25-250 m2/G. Conclusion about the quality of the coating was made from a comparison of the content of pyrolytic carbon in the sample (3.5-4.1 wt.% (C) with the calculated amount of carbon required for the perfect continuous graphene coating the surface of the Al2O3with SBETH=50 m2/g (4.4 wt.% With the density of graphite ρg~2.2 g/cm3), which is quite incorrect. Direct evidence of deposition of carbon in the form nepreryvnog� monosloevogo coverage is not provided. For full monosloevogo coating the surface of the Al2O3, pyrolytic carbon to a greater or lesser degree of ordering of the atoms in the layer (ρC~2 g/cm3probably the required amount of carbon than the design. Another problem is that the quality of the composite material, under certain conditions, a significant impact can have adverse reactions, for example reactions of hydrocarbons flowing in the gas phase. However, the problem of deposition of carbon in the form of a continuous thin layer on the outer surface and pore walls of Al2O3can be solved by carefully selecting the parameters of the CVI process (texture characteristics of Al2O3and its mode of thermal pretreatment, the decomposition temperature of the hydrocarbon, the contact time of the carbon precursor with the matrix Al2O3the speed and duration of decomposition).
The analysis of literature shows that the problems of the development of a realistic technology for the preparation of mesoporous composite materials C/Al2O3with high quality carbon coatings as well as methods of quality assessment, is still not given sufficient attention. To date there are no reports on the synthesis of composites C/Al2O3with a full, evenly dispersed and close to monoclona coal�single coating single-stage CVI method.
The closest in quality of the carbon coating in With/γ-Al2O3composite materials obtained in the work: Lin L et al. Uniformly Carbon-Covered Alumina and Its Surface Characteristics. Langmuir 2005; 21:5040-5046. Composite materials (C/γ-Al2O3received way "impregnation-pyrolysis". In the oxidic matrix used was a commercial γ-Al2O3according to the characteristics of the porous structure (specific surface area, SBETH=128 m2/g, pore volume, ΣV=0,48 cm3/g) is close to γ-Al2O3used by us. As the carbon precursor used sucrose, C12N22O11. The procedure of preparation was as follows. In the first stage, the alumina was impregnable dilute aqueous sucrose solution (weight ratio of WC/WAl=0,3:1). After drying at 90°C carbon-containing precursor "sucrose/γ-Al2O3"pyrolysable in the flow of N2at T=600°C. After 3-fold repetition of the cycle of impregnation-pyrolysis" received a composite material of 12.5% With/γ-Al2O3with evenly dispersed close to monoclona coating. Carbon coating was uneven, if the process of making a composite material of the same composition, a 12.7% With/γ-Al2O3carried per cycle impregnation-pyrolysis using more kontsentrirovannej� sucrose solution (W C/WAl=0,8:1).
The invention solves the problem of cooking With high quality composite/γ-Al2O3materials simple one-step chemical vapor infiltration (CVI) method.
The technical result - carbonaceous composite material With/γ-Al2O3with very high quality thin carbon coating, completely and evenly covering the outer surface and pore walls of granular γ-Al2O3:
The problem is solved by development of a mesoporous composite material carbon-aluminum oxide" C/Al2O3, characterized by the fact that a uniform, continuous and dense layer of pyrolytic carbon has a thickness close to monoclona coverage, equal to 0.4-0.5 nm, the density of the precipitated carbon coating equal to ρC=2.0-2.1 g/cm3the specific surface, SBETH=90-200 m2/g, total pore volume, ΣVο≤0.4 cm3/g, average pore size, DBETH≤10 nm, the most probable pore size, DBJH=5-7 nm, in the absence of micropores.
Mesoporous composite material carbon-aluminum oxide" C/Al2O3that is prepared by decomposition of the gas or gas mixture containing, mol.%: 2-25 a light hydrocarbon or a liquid hydrocarbon and 75-98 argon, on the outer surface and pore walls of granular mesoporous γ-Al2O3, %�SS conducted at a temperature of 750-850°C and at atmospheric pressure, when the contact time between 0.7-4.3 C, the speed of deposition of pyrocarbon 0.01-0.1 gWith×gA1/h, in the absence of a catalyst.
Granular mesoporous γ-Al2O3has a specific surface area SBETH=90-200 m2/g, pore volume ΣVthen≤0.4 cm3/g, average grain size of 100-250 μm.
As hydrocarbon can use a light gas, such as ethylene, propylene, butane-propane mixture, butadiene, and liquid hydrocarbons such as pyridine, hexene, benzene, cyclohexene, liquefied petroleum gas.
The reaction gas mixture has the following composition, mol.%: 2-25 hydrocarbon, 75-98 Ar.
The average size of the granules of γ-Al2O3preferably 100-250 μm.
The decomposition reaction of gas mixtures of composition (mol.%): 2-25 hydrocarbon, 75-98 Ar is carried out in a vertical quartz reactor flow type with vibramicina layer of Al2O3at temperatures of 750-850°C and a pressure of 1 ATM. Hydrocarbons (>99.99%) and Ar (>99,99%) was used without preliminary purification, the air is passed through a gas purification system GAS CLEANER for removal of traces of impurities. The reactor was charged 1-5 g of Al2O3. The reactor was placed in an electrically heated furnace and heated in a stream of argon or in air atmosphere with heating rate 10°C/min to a temperature at which carry out the decomposition of hydrocarbon-containing mixtures. After the temperature in the reactor reaches a predetermined, the reactor was purged with argon for another 30-40 min in the reactor serves the reaction gas or gas-vapor mixture. In the second heating mode (if the reactor linkage with Al2O3is heated to a predetermined temperature in an atmosphere of air), achieving the desired temperature of the air blown out of the reactor with argon and incubated in a stream of argon for another 30-40 min. In the decomposition of liquid hydrocarbon gas-vapor mixture is prepared in situ, passing argon through a bubbler containing liquid hydrocarbon. The temperature of the liquid hydrocarbon in the range of 20-70°With regulate a controlled heating of the bubbler. Feed space velocity of reaction mixtures at 1-6 l/h. the Duration of decomposition of hydrocarbon mixtures vary within 1-8 hours After the end of the experiment the flow of reactants was stopped and the reactor was cooled to room temperature in flowing argon. Carbonaceous product is poured and weighed.
Samples of Al2O3and carbonaceous composite materials are characterized by elemental and x-ray fluorescent analysis, thermal gravimetric analysis (TGA), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy high resolution (PAM BP), low-temperature nitrogen adsorption, dosimetrically methods.
Until now�mob of the day there are no reports, what continuous uniform carbon coating with a layer thickness close to monoclona, was ever received by the infiltration of hydrocarbons in porous alumina.
The invention is illustrated by the following examples, tables and illustrations.
In a quartz flow-type reactor is placed 1-5 g of pure aluminium oxide, Al2O3-1, with grain sizes of 100-200 μm. Put the reactor in a vertically positioned furnace with electric heating and vibrosignal layer of aluminum oxide is heated at a rate of 10°C/min to a temperature of 750°C in air. Once the reactor temperature reaches 750°C, the air blown out of the reactor with argon and the reactor was purged with an argon flow at a speed of 1-5 l/h at a pressure of 1 ATM for another 30-40 min. Then the argon is replaced by Atlanterra gas mixture composition, vol.%: 15S2N4-85Ar. After 6 hours the flow of the reaction mixture is stopped, and the reactor was cooled in a stream of argon to room temperature and poured carbon-coated pellets of aluminum oxide.
Differs from example 2 in that instead of aluminum oxide γ-Al2O3-1 with a specific surface area of SBETH=140 m2/g and a grain size of 100-200 μm are used Al2O3-2 with SBETH=200 m2/g and a grain size of 50-250 microns.
Differs from example 1 in that �place of the reaction mixture, vol.%: 15C2H4-85 Ar use Propylenediamine mixture 15S3N6-85 Ar.
Differs from example 1 in that 1) vibrosignal layer of γ-Al2O3-1 is heated at a rate of 10°C/min is not in the atmosphere of air and in an argon flow at a speed of 1-5 l/h, 2) concentration of ethylene in the reaction mixture. Use the reaction mixture composition, vol.%: 5C2N4-95 Ar.
Differs from example 4 in that the decomposition reaction of atlantageorgia mixture is carried out at a temperature of 800°C.
Differs from example 5 in that the decomposition reaction of atlantageorgia mixture is carried out at a temperature of 850°C.
Differs from example 5 that vibrosignal layer of aluminum oxide is heated at a rate of 10°C/min to a temperature of 800°C in air. Once the reactor temperature reaches 800°C, the air blown out of the reactor with argon and the reactor was purged with an argon flow at a speed of 1-5 l/h at a pressure of 1 ATM for another 30-40 min.
Differs from example 6 that 1) instead of aluminum oxide γ-Various2O3-1 with a specific surface area of SBETH=140 m2/g and a grain size of 100-200 μm are used Al2O3-2 with SBETH=200 m2/g and a grain size of 50-250 microns, 2) the reactor is heated from room temperature to 800°C in Ar flow (1-5 l/h).
Features�I from example 8, what the carbonaceous precursor not use ethylene and liquid hydrocarbon is cyclohexene, S6N10. The reaction mixture With6N10-Ar receive, passing through Ar located at the entrance to the reactor bubbler filled with cyclohexene. T° bubbler = 60°C±3°C.
Differs from example 9 that as the liquid carbon-containing precursor is used not cyclohexene, pyridine, C5H5N.
Characteristics of Al2O3, conditions and composition of the carbonaceous composite material, the carbon content in the samples and the characteristics of the structure of the composites are presented in tables 1-3.
Fig. 1 shows electron microscopic images of pure alumina (γ-Al2O3-1) (a) and (C/γ-Al2O3composite materials prepared according to examples 1 (b) and 4 (C) illustrating a thin coating of the outer surface and pore walls of the alumina layer of carbon. The inset of Fig. 1 (b) shows the magnified image of nanoparticles of Al2O3with monoclonal coated surface.
Fig. 2 shows electron microscopic picture (PAM BP) of the composite sample, demonstrating close to monoclona carbon coating on the pore walls and the surface of�of aluminum oxide. To visualize the coverage of a sample deposited on a microscope grid with a thin layer.
Fig. 3 shows distribution curves of pore size for pure Al2O3-1 (a) and C/Al2O3the composite prepared according to example 1 (b), before and after their incubation in 3.6 M HCl for 2.5 months showing: (a) moderate solubility disapperaring Al2O3-1 and (b) very high stability of the composite material in an acidic environment (the complete preservation of the porous structure).
First of mesoporous composite materials C/Al2O3with very high quality carbon coatings prepared by the method of infiltration of pyrolytic carbon (CVI method) of the porous volume and the external surface of the mesoporous oxide matrix γ-Various2O3. Feature - simple one-step method; uniform, continuous and dense layer of pyrolytic carbon with a true density ρC=2.0-2.1 g/cm3and thick, close to monoclona coverage.
- First of mesoporous composite materials With/γ-Al2O3with a specific surface area of SBETH=100-200 m2/g and a pore volume VΣ=0.21-0.34 cm3/g other than a very high quality carbon coatings prepared with simple one-stage CVI method (chemical vapor infiltration - method of chemical vapor infiltration), (n�and temperatures of 750-850°C and atmospheric pressure).
- As a carbon-containing precursors may be used gaseous and liquid hydrocarbons, e.g., ethylene, propylene, propane-butane mixture, cyclohexene, pyridine.
- As mesoporous oxide matrix can be used commercial γ-Al2O3with a specific surface area of SBETH=50-300 m2/g.
- The first continuous, similar in thickness to monoclona, dense and uniformly dispersed coating the outer surface and pore walls of Al2O3nanoscale carbon layer obtained by deposition/infiltration of pyrocarbon in the porous volume and the external surface of granules of γ-Al2O3. Confirmed by transmission electron microscopy, x-ray photoelectron spectroscopy, low-temperature adsorption of nitrogen.
- The true density of the precipitated carbon coating (ρC) defined by equation (1) as ρC=2.0-2.1 g/cm3, corresponds to the density of pyrolytic carbon.
where: ρCAl*and ρAl*the true density of the samples With/γ-Al2O3composites and the source of aluminum oxide, respectively; % - mass fraction of carbon in the sample.
(* Measured at room temperature in a helium pycnometer Ultrapyc1200e Quantachrome)
- Close to monolayer thickness of the carbon coating in the prepared composites is consistent with the calculated average value of the thickness of the deposited layer (dC=0,4-0,5 nm) under the assumption that the flat surface of the samples:
- High resistance composite material With/γ-Al2O3in an acidic environment, about�caught completeness and high density carbon coatings in combination with the chemical inertness of carbon. Confirmed by low-temperature adsorption of nitrogen.
- Good electrical conductivity of the composite material due to the properties of the carbon coating as the conductor of electric current (unlike azapirones matrix Al2O3which is a dielectric). Confirmed by XPS data.
- High strength and stability of composites With/γ-Al2O3to abrasion, due to the high mechanical strength aluminum oxide.
- High purity, no impurities (confirmed by elemental and x-ray fluorescence analysis), the material does not require additional cleaning or washing.
1. Mesoporous composite material carbon-aluminum oxide" C/Al2O3for use as a sorbent or catalyst carriers, characterized by the fact that a uniform, continuous and dense layer of pyrolytic carbon has a thickness of carbon coating, which is close to monoclona coverage, equal to 0.4-0.5 nm, the density of the precipitated carbon coating equal to ρWith=2.0-2.1 g/cm3the specific surface SBETH=90-200 m2/g, total pore volume ΣVthen≤0.4 cm3/g, average pore size (DBETH≤10 nm, the most probable pore size of DBJH=5-7 nm in the absence of micropores.
2. The method for preparing mesoporous compositing�Togo material carbon-aluminum oxide" C/Al 2O3, characterized by the fact that it is prepared by decomposition of the gas or gas mixture containing, mol.%: 2-25 a light hydrocarbon or a liquid hydrocarbon and 75-98 argon on the outer surface and pore walls of granular mesoporous γ-Al2O3the process is conducted at a temperature of 750-850°C and at atmospheric pressure, contact time (paro)gaseous reaction mixture with the phase of the Al2O30.7-4.3 C, the speed of deposition of pyrocarbon 0.01-0.1 gWith×gA1/h, resulting in a mesoporous composite material C/Al2O3, characterized by the fact that a uniform, continuous and dense layer of pyrolytic carbon has a true density of 2.0-2.1 g/cm3and has a thickness of carbon coating, which is close to monoclona coverage, equal to 0.4-0.5 nm, specific surface area SBETH=90-200 m2/g, total pore volume ΣVthen≤0.4 cm3/g, average pore size (DBETH≤10 nm, the most probable pore size of DBJH=5-7 nm in the absence of micropores.
3. A method according to claim 2, characterized in that the granular mesoporous γ-Al2O3has a specific surface area SBETH=90-200 m2/g, pore volume ΣVthen≤0.5 cm3/g, average grain size of 100-250 μm.
4. A method according to claim 2, characterized in that the hydrocarbon is possible to use light gaseous,�e as ethylene, propylene, butane-propane mixture, butadiene, and liquid hydrocarbons such as pyridine, hexene, benzene, cyclohexene, liquefied petroleum gas.
SUBSTANCE: group of inventions is related to semiconductor materials. A method (version 1) includes provision of a reaction chamber, a semiconductor substrate, a precursor gas or precursor gases, epitaxial CVD growing of a doped semiconductor material at the substrate in the reaction chamber in order to form the first layer, blowing of the reaction chamber with a gas mixture including hydrogen and halogen-containing gas with reduction of dopant memory effect without removal of the respective precipitated layer from the reaction zone and epitaxial CVD growing of the doped semiconductor material at the above substrate in the reaction chamber in order to form the second layer. The semiconductor device contains the semiconductor material received by the above method. The method (version 2) includes introduction of a new semiconductor substrate in the above reaction chamber after the above blowing process and epitaxial CVD growing of the doped semiconductor material at the above new semiconductor substrate.
EFFECT: reproducibility of electrical properties during growing of semiconductor materials.
13 cl, 3 dwg, 1 tbl, 1 ex
SUBSTANCE: invention relates to obtaining coatings by method of chemical sedimentation from gas phase, namely to obtaining protective coatings from chromium and its alloys. Method of application of chromium-based wearproof metal coating includes supply of steam-gas mixture, which contains bis-arene compound of chromium and volatile compound of tin to the surface of heated product in vacuum, as volatile compound of tin applied is 0.1-1.0% tin tetrachloride, and process is carried out at temperature of heated product from 350 to 400 °C. Wearproof chromium-based metal coating contains modifying tin additive, has multi-layer structure from sequentially placed layers based on chromium with modifying tin additive, enriched and depleted of carbon. In depleted of carbon layers content of carbon is 0.5-5.0%, and in enriched with carbon layers - 6.0-12.0%.
EFFECT: increased wear stability of coatings is ensured, which makes it possible to improve tribological characteristics of engine details.
3 cl, 3 dwg, 2 tbl, 2 ex
FIELD: process engineering.
SUBSTANCE: invention relates to pre-treatment of auxiliary surfaces of coating applicators. Auxiliary surfaces of coating applicators are subjected to pre-treatment by application thereon of release ply composed by suspension of graphite powder in volatile solvent. At further coating application coating material adhesion on auxiliary surfaces decreases notably as compared with adhesion without pre-treatment.
EFFECT: simplified procedure.
4 cl, 4 dwg
FIELD: machine building.
SUBSTANCE: reactor for chemical deposition of polycrystalline silicon includes a reaction chamber, comprising a support board fixed in the reaction chamber, and a jacket connected to the support board for formation of the deposition chamber, a filament element attached to the support board, a source of electric current for supply of current to the filament element, a source of silicon-containing gas connected with the reaction chamber to create the flow of silicon-containing gas via the reaction chamber and the vertical pipe, connected to the source of silicon-containing gas, for introduction of the flow of silicon-containing gas into the reaction chamber. The vertical pipe is made as capable of receiving deposits of polycrystalline silicon in the reaction chamber.
EFFECT: improved flow of gas in all volume of a reaction chamber, which makes it possible to increase yield of polycrystalline silicon, improved quality of polycrystalline silicon and reduced energy consumption.
22 cl, 4 dwg
SUBSTANCE: bearing substrate has the first end and the second end located at the distance from each other. A contact seat is arranged on each end of the bearing substrate. The production plant comprises a body, which forms a chamber. At least one electrode is arranged as stretching through the body, besides, this electrode is at least partially arranged inside the chamber for connection with the contact seat. The electrode has outer surface that has an area of contact, which is adapted for contact with the contact seat. An outer coating is arranged on the outer surface of the electrode, outside the contact area. The outer coating has electric conductivity, at least, 9×106 Siemens/metre and corrosion resistance higher than of silver in the row of electrode potentials, which is based on using marine water of room temperature as electrolyte.
EFFECT: slower clogging of an electrode and its increased service life.
28 cl, 5 dwg
SUBSTANCE: bearing substrate has the first end and the second end located at the distance from each other. A contact seat is arranged on each end of the bearing substrate. The production plant comprises a body, which forms a chamber. At least one electrode is arranged as stretching through the body, besides, the electrode is at least partially arranged inside the chamber for connection with the contact seat. The electrode has outer surface that has an area of contact, which is adapted for contact with the contact seat. The contact area coating is arranged on the contact area of the outer surface of the electrode. The coating of the contact area has electric conductivity, at least, 9×106 Siemens/metre and corrosion resistance higher than of silver in the row of electrode potentials, which is based on using marine water of room temperature as electrolyte.
EFFECT: invention makes it possible to reduce problem of electrode clogging and to increase efficiency and service life of an electrode.
29 cl, 7 dwg
SUBSTANCE: invention relates to chemical industry and can be used in producing nanopowder by a plasma-chemical method. The composite nanopowder contains particles consisting of a core, which consists of layers of titanium carbonitride and titanium nitrate, and a cladding which consists of a layer of nickel, with the following ratio of layers of the core and cladding, wt %: TiCxNy, where 0.28≤x≤0.70; 0.27≤y≤0.63; - 24-66; TiN0.6 - 30-67; Ni - 4-9. The method involves feeding a precursor containing titanium nickelide and titanium carbide into a reactor-evaporator, treating in a current of nitrogen plasma at plasma flow rate of 60-100 m/s and at precursor feeding rate of 100-140 g/h, subsequent cooling in a current of nitrogen and trapping the evaporation product on a filter surface. The precursor contains said components in the following ratio TiNi:TiC=25-50:50-75.
EFFECT: obtaining nanocomposite powder which enables to obtain harder alloys.
2 cl, 3 dwg, 2 ex
SUBSTANCE: coatings are obtained from iridium or rhodium; thermal decomposition process is performed at the temperature of 250-450°C and pressure of 0.01-0.05 mm Hg, and as a precursor there used is hydride of iridium tetra-trifluorophosphine of formula HIr(PF3)4 or hydride of rhodium tetra-trifluorophosphine of formula HRh(PF3)4 respectively.
EFFECT: obtaining pore-free microcrystalline coatings with high adhesion to substrate material.
4 tbl, 1 ex
SUBSTANCE: apparatus has a reaction chamber, a support means mounted in the reaction chamber for supporting the substrate to be processed, a gas source for feeding into the reaction chamber starting gas containing the element to be deposited, a catalyst wire lying opposite said substrate and made from tantalum wire with a tantalum boride layer which is formed on the surface of the tantalum wire before feeding the starting gas. Said apparatus also has a heat source for heating the catalyst wire in order to deposit onto the substrate decomposition products of the starting gas formed by catalysis or via a thermal decomposition reaction. Said apparatus further includes a control means for activating heating of the catalyst wire with the heat source through continuous supply of energy.
EFFECT: prolonging service life of the catalyst wire by reducing thermal expansion of the catalyst wire and increasing its mechanical strength.
2 cl, 4 dwg, 1 ex
SUBSTANCE: chamber includes a chamber frame. Insert panels are inserted into the frame mechanically detachably and tightly, besides, some of the insert panels carry functional elements. The chamber frame includes at least one main surface with cantilevers cut from a moulded solid metal panel. Cantilevers are bent in the field of attachment to the main surface so that they form chamber frame links. The side surface of the frame is formed from a solid metal part, in which a material with large surface is cut.
EFFECT: holes are produced for insert panels, where insert panels are installed, no welded joints are required.
11 cl, 10 dwg
SUBSTANCE: invention relates to the field of obtaining pyrocarbon and carbide coatings in a fluidised bed (FB) of particles with a polyfractional composition, changing in the process of the coating precipitation, and can be used in nuclear and electronic equipment. A device for the coating precipitation in FB contains a chemical reactor and a system for the supply of fluidising gas in it. The chemical reactor is made in the form of a right parallelepiped with rounded edges and a rectangle-shaped base. One lateral face of the reactor has a square shape, another lateral face has a shape of a rectangle, whose area equals the area of the base. The ratio of areas of the lateral faces constitutes 1:(1.8-2), with the rectangular faces being provided with convexities in the places where diagonals cross.
EFFECT: increased stability of a totality of particles in the chemical reactor is provided which results in the prevention of a carryover of the particles, which the coating is applied on.
2 cl, 1 dwg
SUBSTANCE: precipitation of pyrocarbon on fuel particles is carried out by supply of hydrocarbon and inert gas mixture into precipitation zone for time τ, increase of the total expenditure of gas mixture by 1.1-1.4 times in comparison with initial value. At time moment, equal τx=(0,45τ-0,55τ), supplied of hydrocarbon is stopped for 1-3 s, and in order to provide optimal mode of fluidisation of fuel particles, consumption of inert gas is increased by value, equal to the product of hydrocarbon consumption at time moment τx and ratio of hydrocarbon and inert gas molecular weights.
EFFECT: reduction of anisotropy coefficient of coating, precipitated from pyrocarbon.
SUBSTANCE: invention relates to the field of high-voltage equipment, to power semiconductor devices, and, in particular, to the method and device for single-stage double-sided application of a coating layer from an amorphous hydrogenated carbon onto the surface of the silicon plate, and also to the holder of the substrate for support of the silicon plate. A silicon plate (4) is used, containing the first large side with the first slant along the edge of the first large side and the second large side with the central section and the second slant along the edge of the second large side surrounding the central section. Besides, the second large side is opposite to the first large side, the silicon plate (4) is placed on the support (31) for the substrate of the substrate holder (3). The support (31) for the substrate is performed with the possibility to ensure contact of only the central section of the second large side of the plate (4) with the support (31) for the substrate. Then the holder of the substrate with the plate (4) is placed into a reaction chamber (8) of a plasma reactor, in which the first and second slants are simultaneously exposed to plasma (6), to produce the deposited layer (7) from the amorphous hydrogenated carbon.
EFFECT: possibility is provided for single-stage double-sided application of a passivating layer, providing for electric inactivity of a section of a semiconductor plate.
17 cl, 5 dwg
SUBSTANCE: pyrolysis of gaseous hydrocarbons and deposition from gas phase onto heated surface of a carbon product is performed. Natural gas is used as hydrocarbons for pyrolysis; deposition is performed at the temperature of 1200-1300°C, at natural gas absolute pressure cyclically varying in the range of 0.1 kg/cm2 to 1.05 kg/cm2; bleeding-in and bleeding-out set within 0.5-5 seconds and 1-10 seconds respectively.
EFFECT: reconstruction of friction wear of carbon products owing to increasing thickness of a deposited coating.
SUBSTANCE: metal strip contains a coating from carbon nanotubes and/or fullerenes soaked with metal chosen from the group consisting of Sn, Ni, Ag, Au, Pd, Cu, W or their alloys. Method for obtaining metal strip with the coating from carbon nanotubes and/or fullerenes and metal involves the following stages: a) application of diffusion barrier layer from transition metal Mo, Co, Fe/Ni, Cr, Ti, W or Ce onto a metal strip, b) application of a nucleation layer from metal salt containing metal chosen from the group Fe, the 9-th or the 10-th subgroup of the periodic table onto the diffusion barrier layer, c) introduction after stages a) and b) of treated metal strip to hydrocarbon atmosphere containing organic gaseous compounds, d) formation of carbon nanotubes and/or fullerenes on metal strip at temperature of 200°C to 1500°C, e) soaking of carbon nanotubes and/or fullerenes with metal chosen from the group containing Sn, Ni, Ag, Au, Pd, Cu, W or their alloys.
EFFECT: obtained metal strip with the coating has improved friction coefficient, increased transition resistance of a contact, increased resistance to friction corrosion, improved resistance to abrasion and increased ability to be deformed.
SUBSTANCE: treatment is carried out in a vacuum chamber (1), in which a device is installed for generation of an electric low-voltage arc discharge (15) (LVAD), a carrier (7) of an item for reception and displacement of items (2) and at least one input (8) for an inertial and/or a reaction gas. The LVAD comprises a cathode (10) and an anode (13) electrically connected with a cathode via an arc generator. The item carrier (7) is electrically connected with a voltage shift generator (16). At least some surface of the anode (13) includes graphite lining.
EFFECT: when operating under high temperature, arc stability is provided, anode contamination is prevented in process of coating application.
41 cl, 7 dwg, 8 ex, 1 tbl
SUBSTANCE: invention relates to nanotechnologies and may be used to produce coatings from nanodiamonds, fullerenes and carbon nanotubes, operating under extreme conditions. Mixture with negative oxygen balance, made of carbon-containing substance and oxidant, is prepared in half-closed resonant detonation chamber 2, which is part of case 1. Carbon-containing substance is produced by ethylene bubbling in bubbler 7 through kerosene heated by means of electric heater 8 in the temperature range from 500 to 750°K. Carbon-containing substance is supplied into half-closed resonant detonation chamber 2 via porous end wall 4, and oxidant - via circular slot supersonic nozzle 3, formed by internal walls 5 and porous wall 4. Then mixture detonation is periodically initiated with frequency of 100-20000 Hz with the help of detonation initiator 6 in medium inertial towards carbon. After detonation, produced flow of carbon nanoclusters from detonation chamber 2 is sent to item 15 with processed surface 16, heated by source of radiant energy 17 to temperature of 550-1300 K. At the same time with the help of drive 13 and control system 14, processed surface 16 is periodically displaced with frequency of at least 1 Hz relative to vector of carbon nanoclusters flow speed in the range of angles from -45 to 45 degrees. Speed of detonation products cooling is maintained in the range from 5·103 to 2·106 K/s.
EFFECT: invention makes it possible to produce coats from carbon nanomaterials on surfaces of bulk products of complex shape and to do fine adjustment of coats parametres.
2 cl, 1 dwg
SUBSTANCE: nitrogen is fed into a vacuum chamber in which there is an ion and a magnetron source until pressure increases to 0.02-0.08 Pa and igniting glow-discharge plasma. A direct voltage ion source for accelerating the stream of nitrogen ions is placed between the cathode and anode and the stream of nitrogen ions cleans the surface of a substrate which is fixed relative the stream of ions and whose temperature is not above 80°C. After cleaning, nitrogen supply is cut and a mixture of nitrogen N2 and toluene C7H8 vapour is fed into the vacuum chamber in ratio N2: C7H8 (90-70)%:(10-30)% until pressure of 0.02-0.05 Pa is established in the chamber and a 40-60 nm thick buffer adhesive layer is deposited, whose refraction index is equal to 1.5-1.8, while power of the ion source varies between 40 W and 60 W and bias voltage of the substrate varies from +50 V to +100 V. Toluene vapour is then fed into the ion source until 0.05-0.1 Pa pressure is achieved and a 80-120 nm thick protective layer is deposited, whose refraction index equals 2.1-2.4, while bias voltage of the substrate varies from -100 V to -200 V and power of the ion source varies from 60 W to 80 W. Vapour of liquid C6H12NSi2 is fed into the ion source until 0.1-0.2 Pa pressure is achieved and bias voltage ranging from -150 V to -250 V is applied across the substrate in order to deposit an anti-dirt layer of α-SiCxNy with thickness of 30-50 nm.
EFFECT: increased protection of organic substances from destructive and contaminating effects of the external medium.
2 cl, 6 dwg
SUBSTANCE: invention relates to sealing porous substrates with pyrolytic carbon through chemical infiltration using an installation for realising said method. One or more porous substrates to be sealed are loaded into a furnace. A reaction gas phase is fed to the input of the furnace, where the said gas phase contains a pyrolytic carbon precursor reaction gas which contains at least one gaseous hydrocarbon CXHy, where x and y are positive integers and 1<x<6 and a carrier gas containing at least one gas selected from methane and inert gases. Flue gas is collected from the output of the furnace and at least a portion of the gas stream extracted from the flue gas and containing the pyrolytic carbon precursor reaction gas is recycled into the reaction gas phase fed into the furnace. At least the amount of pyrolytic carbon precursor gas and carrier gas contained in the gas stream extracted from the flue gas is measured. Depending on the measured amount, at least flow of the said gas stream recycled into the reaction gas phase, flow from external source of the pyrolytic carbon precursor gas and carrier gas injected into the reaction gas phase, and obtaining the required level of content of the pyrolytic carbon precursor gas in the reaction gas phase fed to the input of the furnace are controlled.
EFFECT: lower cost of sealing porous substrates with pyrolytic carbon.
13 cl, 4 dwg
SUBSTANCE: interior electrode for forming shielding film is installed inside plastic container with port and it supplies gaseous medium inside plastic container; it also supplies high frequency power to external electrode located outside plastic container, thus generating plasma of discharge on interior surface of plastic container and creating shielding film on interior surface of plastic container. The interior electrode for forming shielding film consists of a gas supplying tube containing gas propagation path and designed for supply of gas medium and of an insulating element screwed into the end part of the tube so, that it is flushed in it; the insulating element is equipped with a gas outlet communicating with the gas propagation path.
EFFECT: development of electrode for efficient forming of shielding film.
12 cl, 9 dwg
FIELD: power industry.
SUBSTANCE: solar element includes cathode and anode, each having external and internal flexible layers, at that these cathode and anode are located such that their internal layers are opposite each other with clearance filled by the electrolyte, at that the external layer of the cathode is made out of transparent polymer material, and its internal layer is made out of carbon nanotubes, the external layer of the anode is made out of conducting material, and its internal layer is made out of nanoparticles of solid state material, dye-sensitised.
EFFECT: simplified process of solar elements manufacturing, reduced price, and increased flexibility.
11 cl, 1 dwg