Method of obtaining carbon-based composite material and composite material

FIELD: chemistry.

SUBSTANCE: method of obtaining a composite material includes the influence on a mixture of a carbon-containing material, filler and sulphur-containing compound by a pressure of 0.1-20 GPa and a temperature of 600-2000°C. As the sulphur-containing compound applied is carbon bisulphide, a compound from the mercaptan group or a product of its interaction with elementary sulphur. As the carbon-containing material applied is molecular fullerene C60 or fullerene-containing soot. As the filler applied are carbon fibres, or diamond, or nitrides, or carbides, or borides, or oxides in the quantity from 1 to 99 wt % of the weight of the carbon-containing material.

EFFECT: obtained composite material can be applied for manufacturing products with the characteristic size of 1-100 cm and is characterised by high strength, low density, solidity not less than 10 GPa and high heat resistance in the air.

11 cl, 3 dwg, 11 ex

 

The invention relates to composite materials and in particular to composite materials based on carbon and methods for their preparation, and can be used in rocket and space and aviation industries, in the metal processing, processing of natural stone and other hard and superhard materials.

Composite materials are multi-component materials consisting of a polymer, metal, carbon, ceramic or other matrix, matrix) reinforced with fillers from fibers, whiskers, particulate matter, etc. By selection of the composition and properties of the filler and the matrix, their ratio, orientation of the filler is possible to obtain materials with the desired combination of operational and technological properties.

According to the structure of the filler composite materials are divided into fibrous reinforced fibers and filamentary crystals), laminated (reinforced films, plates, layered fillers) and dispergouvannya or dispersion strengthened (with filler in the form of fine particles). The matrix in composite materials provides the solidity of the material, transmission and distribution of stresses in the filler determines the heat-, moisture-, fire - and chemical resistance.

On the nature of the matrix material distinguish polymer, metal, coal�water, ceramic and other composites.

The most widely used technique in received composite materials reinforced with high-strength and high-modulus continuous fibers. Among them of particular interest are:

composite materials based on carbon reinforced with carbon fibers (carbon content);

composite materials based on ceramics, reinforced carbon, carrickbrennan and other heat-resistant fibers.

Much attention is paid to the creation of new composite materials based on well-known and based on the relatively recently opened new modifications of carbon with other elements. There is a possibility of designing materials with desired parameters collected from atomic clusters with the required physico-chemical properties.

Currently described allotropic form of carbon - fullerene, which is used, for example, as a starting product in the production of diamonds (“The fullerens”, edited by H. W. Kroto, J. E. Fischer, D. E. Cox, PergamonPress, Oxford, NewYork, Seoul, Tokyo, 1993).

Fullerene is a molecule in which the carbon atoms (60-240 and more) are interconnected so that they form a hollow body with a shape close to spherical. For example, the molecule of fullerene C60like a football, it is formed by 20 hexagon�and and 12 pentagons. Interatomic distances in the molecule of fullerene C60remained almost as short and strong as in the layer of graphite (i.e., graphene); diameter of the molecule is about 0.7 nm.

Known superhard carbon material and method for its production, wherein the carbon source material used allotropic form of carbon - fullerene C60(patent RF 2127225, 1996).

On fullerene C60exposed to a pressure of 7.5 to 37 GPA and a temperature selected in the range 20-1830°C in the high-pressure apparatus: type "toroid" type of Bridgman anvils, etc. When exposed to the original fullerene pressure and temperature the polymerization of the molecules or fragments of molecules of the fullerene. Compact samples of the material have a high mechanical and electrical properties.

However, despite the high mechanical properties described superhard materials, their thermal conductivity is extremely low.

This, in particular, restricts the use of these materials in cutting tools, as in the absence of dissipation, intensively generated in the contact area of the product and the tool severely restricts the performance of such an instrument, and leads to its failure due to overheating.

In addition, currently known high pressure (7.5-37 HPa) have small quantities,�to limit the size of the product, which can be made of a material obtained in such devices. So, you can easily make the tip of the cutting tool length of 1 cm, but the element airframe length of 1 m to manufacture.

Therefore, products which can be made of a material obtained in a known manner, comprise mainly bits for cutting tools.

Known superhard composite material and manufacturing method thereof (patent RF 2491987, 2011). The method involves high pressure and temperature on carbon source component, which is used as the diamond and binder, wherein the carbon component further comprises a fullerene and/or nanodiamond, and the binder component is used by one or more components selected from the range: alloy silicon bronze, Monel alloy, hard alloy.

The receiving material is carried out in two stages, the first of which in the mixture of initial components is affected by the dynamic pressure of 10-50 HPa at a temperature of 900-2000°C, and the second the resulting material was placed in a high-pressure apparatus and exposed to a static pressure of 5 to 15 GPA and heated to a temperature of 700-1700°C for at least 20 seconds.

The known method allows to obtain a carbon material with high hardness, manage�guest and high wear resistance it gives the possibility to use it in mining, stone processing and Metalworking industries.

However, currently known high pressure (7.5-37 HPa) have small amounts, so limit the size of the product, which can be made of a material obtained in such devices, which prevents the use of the described material in the rocket and space and aviation industries

Known aluminum alloy B95, and a composite based on carbon fibers and epoxy resin, examples which are both durable and lightweight material. These materials have the highest value of strength - σ∗/ρ of about 200 (a measure of the strength - ratio of the tensile strength or lateral bending (in units of MPa) and density (in units of g/cm3) σ∗/ρ)

However, both materials are not very hard (hardness less than 1-2 HPa) and the more heat-resistant (working temperature less than 200°C).

Known carbon-carbon composite materials are durable and heat-resistant, but are not highly consistent (Composite materials. The Handbook edited by V. V. Vasiliev, Y. M. Tarnopolsky. - M., 1990).

Another well-known material is boron carbide, B4C is a lightweight (density 2,52 g/cm3), hard (hardness of about 35 GPA) and heat�tonim (operating temperature up to 2000°C), however, extremely fragile, so that the specified parameter σ∗/ρ for him is practically impossible to determine (G. V. Samsonov, T. Y. Kosolapova, Tomasevic L. T. Properties, methods of preparation and applications of refractory carbides and alloys on their basis. - Kiev, 1974).

Known work (Hard disordered phases produced at high pressure-high temperature treatment of C60. V. D. Blank, V. N. Denisov, N. A. By A.V. Ivlev, B. N. Mavrin, N. R. Serebryanaya, G. A. Dubitsky, S. A. Sulynov, M. Yu. Popov, N. Lvova, S. G. Buga and G. Kremkova. Carbon, V. 36, P 1263-1267 (1998)), which describes a method of producing a high-hardness (hardness between 10 HPa and cubic BN (50 HPa)) carbon material of molecular fullerene C60and this material, named in the “layered cross-linked disordered carbon material”. Very hard (with a hardness of 10-50 GPA) layered cross-linked disordered carbon material, hereinafter referred to as the fullerite W, is obtained in the high-pressure apparatus (at 7-8 GPA and heated 600-1600°C).

The density of fullerite W is about 2.1 g/cm3and the hardness H, as noted above, more than 10 HPa. Using known relationships between strength and hardness, for fullerit W we can expect the value of the specified parameter σ∗/ρ is greater than 1000.

In addition to high hardness, fullerite W has the effect of almost complete elastic recovery of the imprint during indentation that�azvay to its unique mechanical properties when used as a structural material.

And currently known high pressure (7.5-37 HPa) have small amounts, so limit the size of the product, which can be made of a material obtained in such devices.

Thus, the material cannot be used as structural in rocket-space and aviation industries.

In addition, in the process of education fullerit W of fullerene C60there is a significant jump in the volume: the density of the initial fullerene 1.7 g/cm3, while the density of fullerite W 2.1 g/cm3that as a result leads to significant stresses in the sample and, consequently, its cracking. The low thermal conductivity of the initial fullerene (0.4 W/MK) and fullerit W (about 10 W/MK) leads to large temperature gradients during the synthesis, which also leads to cracking of the sample.

In the application for the invention “Compozite materials containing a nanostructured carbon binder phase and a high pressure process” V. Kear, O. Voronov. US 2005/0186104 from 23.03.2004, the authors proposed a composite material consisting of a matrix phase and a binder phase.” As the binder phase of the proposed materials obtained from fullerene under thermobaric treatment of the mixture of fullerene and “matrix phase”. As the matrix phase was proposed to use a variety of carbides, borides, and oxides, � also diamond and carbon fiber. The paper argues that high-strength materials can be obtained from the fullerene at pressures below 7 GPA.

However, this statement is not accurate. As shown by the authors of the study, high strength (and high-hardness, with a hardness above 10 GPA) materials prepared from fullerene C60only in the high-pressure apparatus at 7-8 GPA and heated 600-1600°C, which, as noted above, does not allow to obtain material for products larger than a few centimeters, which eliminates the use of this material as construction material in the rocket and space and aviation industries.

The closest technical solution to the claimed is the above-mentioned method of producing superhard composite material (patent RF 2491987, 2011). The method involves high pressure and temperature on carbon source component, which is used as a diamond, and a binder component, wherein the carbon component further comprises a fullerene and/or nanodiamond, and the binder component is used by one or more components selected from the range: alloy silicon bronze, Monel alloy, hard alloy.

However, despite the fact that known material has a hardness, elasticity and high wear resistance, it is very fragile, and�of the limited amount of currently available high pressure chambers can be obtained with dimensions of 1 cm.

Thus, the currently known technical solutions do not allow to obtain both durable, lightweight, high-hardness and heat-resistant composite structural materials based on carbon.

The technical task of the present invention is the provision of a composite material based on carbon with a low density, high strength with lateral bending, high hardness and heat resistance and its products with a characteristic size of 1-100 cm. (the Term "characteristic dimension" in this case refers to the typical size of products, which can be made of the proposed composite material.)

The aim of the present invention is to provide a method for producing high-strength, high-hardness, heat-resistant and lightweight composite material based on carbon, suitable for the manufacture of products with a characteristic size of 1-100 cm, which can be used in both the aerospace and aviation industries, and in the metal processing, processing of natural stone and other hard and superhard materials.

To this end a method of producing a composite material based on carbon, comprising subjecting the mixture of carbonaceous material and filler pressure and temperature, to the mixture was added with�rotterdamie connection and the impact is carried out at a temperature of 600-2000 ° and a pressure of 0.1-20 GPA.

It is preferable that the sulfur-containing compound is added in an amount from 0.1 to 3 mass % in terms of sulfur by weight of the carbonaceous material.

At the same time as the sulfur-containing compound, a disulfide, or a compound from the group consisting of mercaptans, or the reaction product of a compound from the group consisting of mercaptans with elemental sulfur.

The carbonaceous material used molecular fullerene C60or fullerensoderzhashchie soot.

It is preferable that the filler used boron carbide in an amount of from 30 to 70 mass % by weight of carbonaceous material.

It is preferable that the filler used carbon fiber, or diamond, or nitrides, or carbides, or borides, or oxides in an amount of from 1 to 99 mass % by weight of carbonaceous material.

It is preferable that the exposure is carried out at a temperature of 800-1200 degrees and a pressure of 0.5 to 10 GPA.

To protect it is also proposed that a composite material obtained by the method according to any one of paragraphs 1-8.

It is preferable that the composite material is suitable for manufacturing products with a characteristic size of 1-100 cm

It is known that the high mechanical properties of composite materials based on carbon obul�been the formation of chemical bonds between the matrix and binder phases.

However, as already noted, at the present time to obtain a composite material with good mechanical properties is possible only in the high-pressure apparatus (at 5-15 GPA), where the synthesis process provides durability (due to the formation of chemical bonds) of the connection matrix and binder phases. At lower pressures as the strength of the matrix phase, and the strength of the connection matrix and binder phases is extremely low, and such a composite material will not have any significant strengths in terms of the tensile stress (tensile or bending).

As shown by the study authors, it was possible to choose the elements which are the initiators of the formation of chemical bonds between molecules C60and between C60and other components of the composite material and at lower pressure and temperature. In addition to the initialization of the polymerization reaction C60- 3D (i.e. three-dimensional, when the covalent bond linking the molecules of C60formed in all directions) such substance shall be evenly distributed over the volume of the source material. If this initializer will be evenly distributed throughout the fullerene in the composite, we can expect a more uniform flow of the process of formation of the composite (soprovojdaet�th formation of chemical bonds) and eventually a more even distribution of physico-mechanical properties in the resulting composite. According to the research of the authors this may be a sulfur-containing compound selected from the group: carbon bisulphide or a compound from the group consisting of mercaptans, in particular isoamylalcohol, or the reaction product of a compound from the group consisting of mercaptans with elemental sulfur.

It turned out that among this group, the carbon disulfide CS2best meets the specified requirements. Carbon disulfide CS2potentially has both marked properties. Indeed, it is in the conditions of sintering of the composite material is decomposed with the evolution of elemental sulfur (Tonkov EY, High Pressure Phase Transformations Handbook Vol. 1. Amsterdam: OPA; 1992). Due to the high affinity with carbon atoms of sulfur (after decomposition of CS2) will form the fullerene covalent C-S and transform the fullerene molecule to the radical, which, in turn, initiates the formation of linkages with surrounding molecules or other components of the material. Besides, CS2is a good solvent molecular fullerene C60and therefore easily penetrates the molecular crystal initial C60. Thus, the sulfur atoms may be uniformly distributed in the space occupied by the fullerene. Because such centers are initialized uniformly distributed over the volume occupied by the fullerene, the result is an isotropic product�T.

The filler in the synthesis of the composite material plays a significant role. When forming the matrix of fullerene C60there is a significant jump in the volume: the density of the initial fullerene 1.7 g/cm3, while the density matrix 2.1 g/cm3that as a result leads to significant stresses in the sample and, consequently, its cracking. In addition, the low thermal conductivity of the initial fullerene (0.4 W/MK) and is obtained from the matrix (about 10 W/MK) leads to large temperature gradients during the synthesis, which also leads to cracking of the sample. Filler due to the elastic deformation and a higher thermal conductivity eliminates the above-mentioned effects, which allows to obtain a composite material with no cracks.

In their research the authors used the following known method.

To characterize the structure of the obtained samples used known method of x-ray diffraction analysis.

To control the elemental composition of the samples used in the analysis of known methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope.

To characterize the mechanical properties were carried out according to known methods of measuring the hardness and bending strength.

Hardness was measured by Vickers pyramid or Coppa in soo�accordance with GOST 9450-76.

Measurement of tensile strength in lateral bending σ∗ was performed according to the scheme of three-point bending in accordance with GOST 20019-74.

Elastic moduli were determined by known ultrasonic method.

The values of elastic modules allow to judge about the relationship between the components of the composite. High elastic moduli indicate the presence of chemical bonding between the filler and the resulting synthesis of carbon material.

The ρ density of samples was measured known by hydrostatic weighing.

The final parameter, widely used in the art, which assess the prospects of applications of the material in the rocket and space and aviation industries, is the ratio of strength to density σ∗/ρ.

The resistance of the sample was determined by the method of thermogravimetric analysis.

Fig. 1 shows the results of measurement of tensile transverse bending of the sample composite material synthesized from a mixture of C60and B4C (50/50 weight %) in the presence of CS2at a pressure of 2 GPA and a temperature of 1000°C. tensile strength in lateral bending σ∗bending=570 MPa.

Fig. 2 shows the measurement results of the compressive strength of the sample composite material synthesized from a mixture of C60and B4C (in a ratio of 50/5 weight %) in the presence of CS 2at a pressure of 2 GPA and a temperature of 1000°C. the Limit of compressive strength σ∗grip=2250 MPa.

Fig. 3 presents the results of thermogravimetric analysis of the samples held up to 1400°C in air. The lower curve corresponds to the sample composite material synthesized from a mixture of C60and B4C (50/50 weight %) in the presence of CS2at a pressure of 2 GPA and a temperature of 1000°C. the Upper curve corresponds to the powder source of boron carbide.

The following examples illustrate the invention without limiting its merits.

Example 1. Obtaining a composite material in accordance with the invention at a pressure of 0.1 GPA.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder of molecular fullerene C60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the mill.

Carbon disulfide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar to obtain a smooth consistency and is used for the manufacture of samples.

This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 0.1 GPA and heated to a temperature of 1000°C with wremen� extract 100 C. After unloading the specimen examined by x-ray diffraction, Raman spectroscopy, transmission electron microscope, conduct thermogravimetric analysis and investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained in this example, the material is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the resulting material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending, carried out according to the scheme of three-point bending (GOST 20019-74), giving the value of ultimate strength in lateral bending σ*bending=400 MPa.

The density was measured by hydrostatic weighing. The density of the sample ρ is 2.20 g/cm3.

The specified parameter σ*/ρ=180, i.e., the resulting material is superior to many of the materials used in rocket and space and aviation industries.

Thermogravimetric analysis of the sample conducted to 1400°C in air, showed a weight gain of about 3%, starting from a temperature of 800°C, which is associated with the oxidation of boron carbide. In General, about�the sample was heat-resistant.

Thus, the composite material sample obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 2. Obtaining a composite material in accordance with the invention at a pressure of 0.5 GPA.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder of molecular fullerene C60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the mill.

Carbon disulfide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar to obtain a smooth consistency and is used for the manufacture of samples.

This mixture was charged into a high pressure chamber type piston-cylinder displacement 100 mm diameter, load up to a fixed pressure of 0.5 GPA and heated to a temperature of 1000°C with a holding time of 100 s. the resulting sample has a diameter of 100 mm. From samples of this size can be manufactured, in particular, a heat shield or turbine blade.

After unloading the specimen examined by x-ray diffraction, Raman spectroscopy, transmission electron microscope, conduct thermogravimetric analysis and investigate its mechanical properties.

The hardness measured�Ute Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained in this example, the material is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the resulting material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending, carried out according to the scheme of three-point bending (GOST 20019-74), giving the value of ultimate strength in lateral bending σ*bending=500 MPa.

The density was measured by hydrostatic weighing. The density of the sample ρ is at 2.23 g/cm3.

The specified parameter σ*/ρ=220, i.e., the resulting material is superior to many of the materials used in rocket and space and aviation industries.

Elastic moduli determined by ultrasonic method. The average values of the elastic moduli of the sample are: young's modulus E=150 GPA, the bulk modulus of compression K=110 GPA, shear modulus G=60 GPA. High elastic moduli indicate the presence of chemical bonding between the boron carbide and the resulting synthesis of carbon material.

Thermogravimetric analysis of the sample conducted to 1400°C in air, showed a weight gain of about 3% since temperature°C, due to the oxidation of boron carbide. Overall, the sample was heat-resistant.

Thus, the composite material sample obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 3. Obtaining a composite material in accordance with the invention at a pressure of 2 GPA.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder With molecular60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the vibrating mill. Carbon disulfide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar until a homogeneous consistency and used to make samples. This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 2 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading the specimen examined by x-ray diffraction, Raman spectroscopy, transmission electron microscope, conduct thermogravimetric analysis and investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained by the authors of the material is in the range of 10-70 G�and, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending, carried out according to the scheme of three-point bending (GOST 20019-74), giving the value of ultimate strength in lateral bending σ*bending=570 MPa (Fig. 1) and the limit of compressive strength of 2250 MPa (Fig. 2).

The density was measured by hydrostatic weighing. The density of the sample ρ is 2.3 g/cm3.

The specified parameter σ*/ρ=250.

Elastic moduli determined by ultrasonic method. The average values of the elastic moduli of the sample are: young's modulus E=190 GPA, the bulk modulus of compression K=120 GPA, shear modulus G=75 GPA. High elastic moduli indicate the presence of chemical bonding between the boron carbide and the resulting synthesis of carbon material.

Thermogravimetric analysis of the sample conducted to 1400°C in air, showed a weight gain of about 3%, since the temperature of 600°C, which is associated with the oxidation of boron carbide (Fig. 3, lower curve). Overall, the sample was heat-resistant. For comparison, Fig. 3 shows the results of thermografie�parametric analysis for initial powder of boron carbide carried out under the same conditions. In the latter case, there is a weight gain of about 100%, associated with the oxidation, despite the fact that boron carbide relates to heat-resistant materials (Fig. 3, upper curve). Therefore, in the composite material see a significant increase in heat resistance relative to the source In4S.

Thus, the composite material sample obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 4. Obtaining a composite material at a temperature of 600-2000°C, in accordance with the invention.

Produce some samples. For this purpose, the powder of boron carbide In4C (with an average grain size of 100 nm) mixed with the powder With molecular60(with an average grain size of 1 μm) in a weight ratio of 30/70% and 70/30% in the vibrating mill. The total weight of the mixture in each case is 2 g. carbon Disulphide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar until a homogeneous consistency and used to make samples. This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 1 GPA and heated to a fixed temperature with a fixed shutter speed when �specified temperature. Samples were obtained at temperatures 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600 and 2000°C with exposure times 0,1, 1, 10, 30, 60, 120 and 180 C. After unloading the samples are examined by x-ray diffraction, Raman spectroscopy, transmission electron microscope, conduct thermogravimetric analysis and investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness of the samples is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending is carried out according to the scheme of three-point bending (GOST 20019-74). The density was measured by hydrostatic weighing. The specified parameter σ*/ρ of the obtained samples not below 200. The samples are stable at least up to 1400°C.

Therefore, composite samples obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 5. Obtaining a composite material in accordance with the invention, where the carbonaceous material is used in the full�ensolarado soot.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder fullerenelike soot (with an average grain size of 1 μm) content6060% in an amount of 1 g (weight ratio of 50/50%) in the vibrating mill. Carbon disulfide CS2added to the resulting mixture fullerenelike soot and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. The mixture is then fullerenelike soot, In4C and CS2triturated in an agate mortar until a homogeneous consistency and used to make samples. This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 1 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading investigate its mechanical properties of the sample.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained by the authors of the material is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the resulting material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending is carried out �about three-point bending scheme (GOST 20019-74). The density was measured by hydrostatic weighing. The specified parameter σ*/ρ of the obtained samples is 100. The samples are stable at least up to 1400°C.

Therefore, composite samples obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 6. Obtaining a composite material in accordance with the invention.

Produce a few samples, each from diamond powder, silicon carbide SiC, aluminum nitride AlN, alumina Al2O3, zirconium dioxide ZrO2in an amount of 1 g mixed with the powder With molecular60in an amount of 1 g (weight ratio of 50/50%) in the vibrating mill. Carbon disulfide CS2add to the mixture With60and each of these powders (SiC, AlN, Al2O3and ZrO2) in an amount of 0.05 ml of CS2per 1 g of the mixture. Then obtained with the addition of CS2the mixture is triturated in an agate mortar until a homogeneous consistency and used to make samples. For this purpose, each of the mixtures were charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 1 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading investigate the mechanical properties of the samples.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). Hardness�scientists of the material is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the resulting material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending is carried out according to the scheme of three-point bending (GOST 20019-74). The density was measured by hydrostatic weighing. The specified parameter σ*/ρ of the obtained samples is not less than 100. The samples are stable at least up to 1000°C.

Therefore, composite samples obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 7. Obtaining a composite material in accordance with the invention, where the carbonaceous material used carbon fiber.

Carbon disulfide CS2added to the powder With molecular60in an amount of 0.05 ml of CS21 g60. The mixture is then triturated in an agate mortar until a homogeneous consistency. The resulting mixture was added carbon fiber in a weight ratio of 50% to the fullerene C60and mix thoroughly with a spatula. Then the mixture in an amount of 2 g was charged into the chamber of the high pressure type piston-cylinder Nagraj�Ute to a fixed pressure of 2 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading investigate the mechanical properties of the samples.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness of the material obtained is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the resulting material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending is carried out according to the scheme of three-point bending (GOST 20019-74). The density was measured by hydrostatic weighing. The specified parameter σ*/ρ of the obtained samples is not less than 100. The samples are stable at least up to 1000°C.

Therefore, composite samples obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 8. Obtaining a composite material in accordance with the invention, where the filler used cubic boron nitride.

The powder of cubic boron nitride (c-BN (with average grain size about 1 μm) in an amount of 1 g mixed with the powder With molecular60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the vibrating mill. CS 2add to the mixture With60and c-BN in the amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60, c-BN and CS2triturated in an agate mortar until a homogeneous consistency and used to make samples. This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 2 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading the specimen examined by x-ray diffraction, Raman spectroscopy, transmission electron microscope and investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained by the authors of the material is in the range of 10-70 HPa, and the material is very hard.

Elemental analysis carried out by the methods of energy-dispersive and wave spectroscopy using an electronic scanning microscope. Conducted elemental analysis shows the presence of sulfur in the material is less than 0.01%, i.e., sulfur is removed from the resulting material in the synthesis process.

Measurement of tensile strength in lateral bending, carried out according to the scheme of three-point bending (GOST 20019-74), give the value of the tensile strength σ*bending=300 MPa.

The density was measured by hydrostatic weighing. The density of the sample ρ is 2.8 g/cm3.

p> The samples are stable at least up to 1400°C in a protective atmosphere.

Therefore, composite samples obtained is both durable, lightweight, high-hardness and heat-resistant.

Example 9. Obtaining a composite material at temperatures outside the temperature range of 600-2000°C.

Produce some samples. For this purpose, the powder of boron carbide In4C (with an average grain size of 100 nm) mixed with the powder With molecular60(with an average grain size of 1 μm) in a weight ratio of 50/50% in a vibrating mill. The total weight of the mixture in each case is 2 g. carbon Disulphide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar until a homogeneous consistency and used to make samples. This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 2 GPA and heated to a fixed temperature with a fixed holding time at this temperature. Samples were obtained at temperatures of 400 and 2400°C with a holding time of 100 s. After unloading the sample to investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness of the obtained samples has a value�Oia below 10 HPa, and the material is not very hard.

Thus, a composite material obtained samples is not very hard.

Example 10. Preparation of composite material outside the pressure range of 0.1-20 GPA.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder of molecular fullerene C60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the mill.

Carbon disulfide CS2add to the mixture With60and In4C in an amount of 0.05 ml of CS2per 1 g of the mixture. Then the mixture With60In4C and CS2triturated in an agate mortar to obtain a smooth consistency and is used for the manufacture of samples.

This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 0.05 HPa (receipt of samples at pressures above 20 GPA is technically complex and is heated to a temperature of 1000°C with a holding time of 100 s. After unloading the sample to investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness of the samples have values below 10 GPA, and the material is not very hard.

Thus, a composite material obtained samples is not very hard.

Example 11. The receiving component�itogo material in accordance with the invention using a mercaptan or thiol instead of carbon disulfide.

The powder of boron carbide In4C (with an average grain size of 100 nm) in an amount of 1 g mixed with the powder of molecular fullerene C60(with an average grain size of 1 μm) in an amount of 1 g (weight ratio of 50/50%) in the mill.

Soumillion C5H11SH or thiol C6H5SH is added to the mixture With60and In4C in an amount of 0.05 ml C5H11SH or C6H5SH on 1 g of the mixture. Then the mixture With60In4C and C5H11SH or C6H5SH triturated in an agate mortar to obtain a smooth consistency and is used for the manufacture of samples.

This mixture was charged into a high pressure chamber type piston-cylinder, load to a fixed pressure of 2 GPA and heated to a temperature of 1000°C with a holding time of 100 s. After unloading the sample to investigate its mechanical properties.

Hardness is measured by Vickers pyramid or Coppa (GOST 9450-76). The hardness obtained by the authors of the material is in the range of 10-70 HPa, and the material is very hard.

Measurement of tensile strength in lateral bending, carried out according to the scheme of three-point bending (GOST 20019-74), giving the value of ultimate strength in lateral bending σ*bending=530 MPa.

The density was measured by hydrostatic weighing. The density of the sample ρ is 2.3 g/cm3 .

The specified parameter σ*/ρ=230.

Thermogravimetric analysis of the sample conducted to 1400°C in air showed that the sample was heat-resistant.

Thus, the composite material sample obtained is both durable, lightweight, high-hardness and heat-resistant.

1. A method of obtaining a composite material based on carbon, comprising subjecting the mixture of carbonaceous material and filler pressure and temperature, characterized in that a mixture of sulfur-containing compound, and exposure is carried out at a temperature of 600-2000 ° and a pressure of 0.1-20 GPA.

2. A method according to claim 1, characterized in that the sulfur-containing compound is added in an amount from 0.1 to 3 mass % in terms of sulfur by weight of the carbonaceous material.

3. A method according to claim 1, characterized in that as the sulfur-containing compound, a disulfide.

4. A method according to claim 1, characterized in that as the sulfur-containing compound, a compound from the group of mercaptans or the reaction product of a compound from the group consisting of mercaptans with elemental sulfur.

5. A method according to claim 1, characterized in that the carbonaceous material used molecular fullerene C60.

6. A method according to claim 1, characterized in that the carbonaceous material is used in fullerene�arrasou soot.

7. A method according to claim 1, characterized in that the filler used boron carbide in an amount of from 30 to 70 mass % by weight of carbonaceous material.

8. A method according to claim 1, characterized in that the filler used carbon fiber, or diamond, or nitrides, or carbides, or borides, or oxides in an amount of from 1 to 99 mass % by weight of carbonaceous material.

9. A method according to claim 1, characterized in that the exposure is preferably conducted at a temperature of 800-1200 degrees and a pressure of 0.5 to 10 GPA.

10. Composite material obtained by the method according to any one of claims. 1-9.

11. Composite material according to claim 10, characterized in that it is designed for production of products with a characteristic size of 1-100 cm



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: graphite-oxide firebrick including carbon containing component, periclase and binding substance, contains artificial graphite and crystalline graphite as carbon containing component, and polyphosphate binder with refractoriness up to 2000°C as binding substance, at the following components ratio in wt %: artificial graphite 36-50, crystalline graphite 14-20, periclase 20-30, polyphosphate binding substance - rest.

EFFECT: firebrick of improved heat resistance, oxidability and industrial safety.

2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to diamond-containing composite materials used in different fields of electronics as heatsinks. The method includes preliminary agglomeration of diamond powder by cold pressing said powder and temporary polymer binder followed by heat treatment at temperature of full removal of volatile substances from the temporary binder to obtain a porous workpiece and final agglomeration-sintering of the workpiece by soaking with liquid metal. Soaking of the porous workpiece during final agglomeration-sintering of the diamond powder is carried out with copper via capillary condensation of the vapour thereof at temperature in the range of 900-1000°C on the workpiece and reactor pressure of not more than 36 mmHg at temperature of the copper vapour higher than the temperature of the workpiece.

EFFECT: high efficiency of the articles as heatsinks while simplifying the production technology thereof.

1 tbl, 8 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of sealed articles for chemical industry and metallurgy. First, carcass of refractory fibre is made that features linear expansion factor approximating to that of the matrix material components. Then, carcass is compacted by carbon-bearing material to get the billet of porous carbon-bearing composite impregnated with ceramics-forming binder that makes a precursor of silicon nitride and/or carbide. Plastic billet is formed at binder solidification temperature and processed at its final temperature of 1300-1600°C. Then, carbon is introduced in material pores. Then, siliconising is performed by vapour-liquid-phase process at heating, holding and cooling in silicon vapours. For this capillary condensation of silicon vapours is conducted at 1300-1600°C and reactor pressure not over 36 mmHg followed by holding at 1600-1700°C for 1-2 hours. Finished article finished is cooled and withdrawn from the unit.

EFFECT: longer life.

4 cl, 1 tbl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention refers to manufacturing of polycrystalline materials, which can be used, preferentially for producing drilling and dressing tools. A polycrystalline diamond composite with a dispersion-strengthened additive contains a refractory metal coating 0.02-0.15 mm thick containing diamond powder and metals with the metal presented by nickel, cobalt, whereas the dispersion-strengthened additive is tungsten carbide nanopowder in the following proportions, wt %: diamond - 85-90, nickel - 7-9, cobalt - 2-4, tungsten carbide nanopowder - 0.1-3.0.

EFFECT: technical effect consists in increasing the strength and wear resistance of the sintered composite, and selecting the high-melting coating ensures the reliable attachment of the material in the drilling tool.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining a moulded product from a carbon material and can be used as graphite electrodes and connecting elements for electrothermal processes. The method includes the following stages: a) milling production wastes or spoiled products from a composite material reinforced with carbon fibres with sieving dust, with the said material representing a polymer reinforced with carbon fibres, carbon reinforced with carbon fibres or concrete reinforced with carbon fibres; b) obtaining a mixture from the milled product obtained at stage a), a binding substance such as pitch, a carbon material such as coke, and optionally one or several additives, with the said mixture containing less than 20 wt % of fibres; c) moulding the obtained mixture into the moulded product; d) carbonisation of the moulded product. After carbonisation the product can be soaked with a soaking preparation with further graphitisation.

EFFECT: increased strength and resistance of the products to temperature changes with the simplification of the method of their production.

15 cl, 1 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: liquid phenolformaldehyde resin is mixed with powder of oxalic acid of various fractional composition (as pore former) until homogeneous plastic mass is obtained, workpieces are formed by vibration impact and hardened, thermal processing in static atmosphere in the interval of temperatures from 210 to 250°C and pyrolytic carbonisation in protective medium are carried out. Workpiece hardening is realised at temperature 60-80°C for 20-60 minutes. Before carbonisation it is possible to introduce precursors of metals from iron group into obtained porous workpiece by method of impregnation. Pore-former is removed from workpiece by method of extraction. Method is technologically simple and economically profitable.

EFFECT: reduction of density and increase of strength with simultaneous preservation of specific adsorption surface of obtained material.

4 cl, 2 dwg, 1 tbl

FIELD: metallurgy.

SUBSTANCE: invention relates to the production of items from carbon-containing materials and is intended to protect them against oxidation under conditions of an oxidising medium at high temperatures. It can be used in the metallurgical industry and in other industries, including the aircraft industry. The method involves shaping on the surface of the item of a dross coating based on a composition consisting of a mixture of fine powders of carbon and a compound(s) that is(are) inert to silicone at least to 1600°C, and a temporary binding agent, heating of the item in vacuum up to 1600-1700°C in silicone vapours in a closed volume of the reactor, which provides for the capillary condensation of silicone vapours in pores of the coating at a temperature of 1300-1600°C, exposure at 1600-1700°C and cooling. As the compound(s) that is(are) inert to silicone, nitrides of metals or boron are used, which are decomposed with the release of volatile products at heating in a gas flow at a temperature of 1700-2000°C or converted under the specified conditions to silicides of the appropriate metals and/or triple compounds, the so called Nowotny phases, of Me3SiC2 and/or Me5Si3C composition, where Me is metal.

EFFECT: providing a possibility of using the coatings under conditions of an oxidising medium at the gas flow temperature of more than 1900°C.

3 cl, 5 ex, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to diamond-based composite materials, obtained by sintering diamond grains and metals with dispersion-strengthening additives and reinforcing CVD diamond component in form of insert, modified under conditions of high pressure and temperature, and can be used for production of drilling and dressing tools. Diamond semi-crystalline composite material with dispersion-strengthening additive contains refractory shell, in which powders of diamond, metal and CVD diamond insert are placed. Shell is made of refractory metal, mainly tantalum and niobium. Nickel, cobalt are used as metals, and tungsten carbide nanopowder is used as dispersion-strengthening additive with the following component ratio, wt %: diamond powder and CVD diamond insert 85-90, nickel 7-9, cobalt 2-4, tungsten carbide nanopowder 0.1-3.0.

EFFECT: increase of hardness and wear-resistance of reinforced with CVD diamond sintered composite and reliable fixation of material in drilling instrument.

1 ex, 1 tbl

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil processing industry and can be used at processing of oil or heavy hydrocarbon compounds to obtain a volumetric carbon frame for composite materials. In compliance with the proposed method, a formwork is prepared, the cross section of which determines a profile of the carbon frame, and mass of a solid-state melting catalyst - blowing agent is formed inside the formwork by means of individual components having either a regular or irregular geometrical shape; besides, laying of the individual components is performed so that an inter-rib gap forms continuous inter-rib formwork channels along ribs and tops of the laid bodies. A raw mixture is prepared by addition to heavy hydrocarbon compounds of a cocatalyst consisting of a mixture of light hydrocarbons; the inter-rib formwork channels are filled inside the formwork in the body of the mass of the solid-state melting catalyst - blowing agent with the raw mixture; the formwork is fully placed into a melt of a catalytic mixture having the temperature of 200-300°C, and the formwork is exposed in the melt of the catalytic mixture till melting of the mass of the solid-state melting catalyst - blowing agent and formation of a volumetric carbon frame. Then, the formwork is removed together with the obtained volumetric carbon frame and the latter is cleaned from residues of the liquid melt of the catalytic mixture. As a melting catalyst - blowing agent, a mixture of metal chlorides is used, which has a melting temperature of 180-200°C.

EFFECT: simpler production of a carbon frame owing to excluding a carbon fibre production stage.

16 cl, 3 tbl, 4 dwg

FIELD: chemistry.

SUBSTANCE: graphite-containing component is mixed with a kaolin-based filling agent, dry mixing with simultaneous dispersion successively in a drum and centrifugal mixers is carried out. After that, a magnetised water solution of an alumoborophosphate concentrate, containing a surface-active substance, is introduced, and a wet batch in a screw mixer is carried out. After that, the obtained mass is processed in a tribochemical disperser under conditions of vacuuming and all-around compression to a pressure of 5-20 MPa. The tribochemical disperser includes a hermetic hollow cylindrical case 40, which has flanges 41 and 42 on butt ends, a permeable piston 44 with a rod 45, a drive 46 of reciprocating movement, means for the cavity vacuuming 43, two vacuum gate valves 471 and 472. The piston 44 represents a packet of adjoining each other pairs of metal nets which have the different cell size, located between two protective grids 445. The products are moulded from processed mass with their further thermal processing.

EFFECT: reproducibility of specific electric resistance in the products is provided, with the nanocomposite mass acquiring isotropic properties and ductility.

20 cl, 4 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: invention refers to manufacturing of polycrystalline materials, which can be used, preferentially for producing drilling and dressing tools. A polycrystalline diamond composite with a dispersion-strengthened additive contains a refractory metal coating 0.02-0.15 mm thick containing diamond powder and metals with the metal presented by nickel, cobalt, whereas the dispersion-strengthened additive is tungsten carbide nanopowder in the following proportions, wt %: diamond - 85-90, nickel - 7-9, cobalt - 2-4, tungsten carbide nanopowder - 0.1-3.0.

EFFECT: technical effect consists in increasing the strength and wear resistance of the sintered composite, and selecting the high-melting coating ensures the reliable attachment of the material in the drilling tool.

1 tbl, 1 ex

FIELD: process engineering.

SUBSTANCE: initial mix is prepared to contain the following components in wt %: fullerite C60 and/or C70 - 30-70; boron with grain size of up to 2 mcm - 70-30. At first step, produced mix is processed in gasostat in inert gas at 50-120 MPa and 1500-1850°C with subsequent holding for 15-180 minutes. Then, temperature is decreased to the room temperature while pressure is decreased to barometric pressure. At second step, pressure of at least 7 GPa and temperature of at least 1400°C are applied for at least one minute. Then, temperature is decreased to the room temperature while pressure is decreased to barometric pressure. Produced material features modulus of elasticity of 390-460 GPa, bulk modulus of 210-380 GPa, shear modulus of 170-180 GPa and hardness of 42-90 GPa. It represents a homogeneous high-dispersion matrix of boron carbide diamonds uniformly distributed therein, sized to about 1 mcm and actual density of at least 98% of theoretical magnitude.

EFFECT: production of high-pressure hardware, high wear-resistance materials, cutting and drilling tools.

2 cl, 4 dwg, 3 ex

FIELD: nanotechnology.

SUBSTANCE: invention relates to nanotechnology and can be used for labelling molecules, quantum information processing, magnetometry, and synthesis of diamond by chemical vapour deposition. Crystalline diamond powder with a maximum particle size of 2 microns to 1 mm is ground by the nitrogen jet for 1-5 hours with the grinding pressure of 500 kPa to obtain the fine powder which is then milled in a planetary mill with balls of tungsten carbide. The resulting nano-ground powder is autoclaved with the mixture of hydrofluoric acid and nitric acid at a temperature of 100-200°C. The fluorescent cubic nanocrystals of diamond of predominantly circular shape are recovered by centrifugation, with a maximum size of not more than 100 nm, comprising up to 2,000 ppm alloy addition, such as nitrogen, and up to 50 ppm of impurities. The surface of the diamond nanocrystal comprises a layer of amorphous carbon.

EFFECT: obtaining diamond nanocrystals.

15 cl, 8 dwg

FIELD: chemistry.

SUBSTANCE: molecular fullerene C60 or fullerene-containing soot with an additive of a sulphur-containing compound is subjected to pressure of 0.2-12 GPa and temperature of 0-2000°C. The sulphur-containing compound used is carbon sulphide, a mercaptan group compound or a product of reacting a mercaptan group compound and elementary sulphur. The structure of the obtained high-hardness carbon material is formed by covalently bonded layers of fullerene molecules which are two-dimensionally polarised along a second-order axis of rotation.

EFFECT: hardness of the obtained material is greater than 10 GPa.

4 cl, 5 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: synthetic radioactive nanodiamond consists of particles with an average diameter of not more than 100 nm and contains metal-containing radioactive impurities in amount of 0.04-1.24 wt %, with γ-radiation dose rate of less than 180 mcSv/h, γ+β-radiation dose rate of less than 720 mcSv/h. The radioactive nanodiamond is obtained by irradiating synthetic nanodiamonds, which contain metal-containing impurities, with neutron flux with neutron fluency of 1.4-1.46·1019 neutrons/cm2.

EFFECT: technique for producing a radioactive nanodiamond is simple, safe, reliable and enables to set up industrial production.

2 cl, 8 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: conjugate represents nanodiamond particles with size 2-10 nm with pyrophosphorase, immobilised on them by means of linker, containing amino or amide groups. Content of pyrophosphatase constitutes 0.1-1 mg per 1 mg of nanodiamond, with specific activity of pyrophosphatase constituting to 95±5% of native pyrophosphatase activity. method of conjugate obtaining includes dissolution of nanodiamond with grafted hexamethylenediamine and/or nanodiamond aminated with ammonia in water, successive addition of water buffer solution HEPES with pH 7-8, magnesium chloride, sodium fluoride, sodium pyrophosphate, pyriphosphatase, and glutaraldehyde. After that, obtained mixture is exposed for 0.5-12 h, centrifuged, washed with water buffer solution Tris-HCl and dried.

EFFECT: obtaining conjugate of nanodiamond with pyrophosphatase, possessing increased stability.

3 cl, 1 tbl, 2 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing coloured diamond materials, which can be applied as precious stones or cutting instruments. Method includes stages of growing monocrystalline diamond material in accordance with CVD-technology, with diamond material having concentration of single substituting nitrogen atoms [Ns0] less than 1 ppm; initial CVD-diamond material is colourless, or, in case it is not colourless, then, according to colour gradation brown or yellow, and if it is brown according to colour gradation, then it has level G (brown) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and if it is yellow according to colour gradation, it has level T (yellow) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and irradiation of initial CVD-diamond by electrons to introduce isolated vacancies into diamond material in such a way that product of the total concentration of vacancies × way length [Vt]×L, in irradiated diamond material at said stage or after additional processing after irradiation, including annealing irradiated diamond material at temperature at least 300°C and not higher than 600°C, constitutes at least 0.072 ppm cm and not more than 0.36 ppm cm.

EFFECT: diamond material becomes fancy light-blue or fancy light greenish blue in colour.

21 cl, 4 dwg, 3 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: method of obtaining tritium-marked nanodiamonds by method of thermal activation of tritium includes preparation of water suspension of nanodiamonds with average size of particles not more than 125 nm and content of dispersive phase from 0.15 to 0.6 mg, uniform application of obtained suspension on walls of vessel, which contains placed with possibility of electric current connection tungsten filament for tritium activation, with the following lyophilisation and air removal. In the process of carrying out reaction with atomic tritium temperature of walls of reaction vessel is supported in the range 291- 298 K, with its bottom being cooled to 77 K. Introduction of gaseous tritium and its activation on tungsten filament is carried out for 5-15 sec, after which remaining tritium is removed. Stage of introduction of gaseous tritium and its activation is repeated from one to eight times. Obtained are tritium-marked nanodiamonds, in which tritium is bound with nanodiamond by C-H bond, characterised by specific radioactivity not less than 1 TBq/g.

EFFECT: improvement of characteristics.

3 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: incubation medium, oxidation substrate and tetraphenylphpsphonium chloride as indicator are placed into respective measuring cell of installation for measuring mitochondria potential, provided with tetraphenylphosphonium-selective electrode, change of tetraphenylphosphonium concentration is registered and when constant tetraphenylphosphonium concentration is achieved, mitochondria, isolated from animal organism, are added. Change of membrane potential of mitochondria is registered by change of electrode signal, when constant potential is achieved, respective water suspensions of analysed samples of nanodiamonds with pH 7.2-7.4 are added, and value of rate of change of mitochondria membrane potential is measured. Presence of statistically reliable difference of rates of mitochondria membrane potential change testifies to biological inequivalence of compared samples of nanodiamonds.

EFFECT: expressive and available method of determining biological inequivalence of nanodiamonds.

2 cl, 1 tbl, 1 dwg, 1 ex

Diamond material // 2537857

FIELD: chemistry.

SUBSTANCE: inventions can be used in chemical and jewellery industry. Nitrogen-doped diamond material, obtained in accordance with CVD technology, or representing monocrystal or precious stone, demonstrates difference of absorptive characteristics after exposure to radiation with energy of at least 5.5 eV, in particular UV radiation, and thermal processing at temperature 798 K. Defects into diamond material are introduced by its irradiation by electrons, neutrons or gamma-photons. After irradiation, difference in absorptive characteristics decreases.

EFFECT: irradiated diamond material has absorption coefficient lower than 0,01 cm-1 at 570 nm and is capable of changing its colour.

18 cl, 7 dwg, 11 tbl, 15 ex

FIELD: chemistry.

SUBSTANCE: invention relates to inorganic chemistry, namely to obtaining silicon-carbide materials and products, and can be applied as thermal-protective, chemically and erosion resistant materials, used in creation of aviation and rocket technology, carriers with developed surface of heterogeneous catalysis catalysts, materials of chemical sensorics, filters for filtering flows of incandescent gases and melts, as well as in nuclear power industry technologies. To obtain nanostructures SiC ceramics solution of phenolformaldehyde resin with weight content of carbon from 5 to 40% with tetraethoxysilane with concentration from 1·10-3 to 2 mol/l and acidic catalyst of tetraethoxysilane hydrolysis id prepared in organic solvent; hydrolysis of tetraethoxysilane is carried out at temperature 0÷95°C with hydrolysing solutions, containing water and/or organic solvent, with formation of gel. Obtained gel is dried at temperature 0÷250°C and pressure 1·10-4÷1 atm until mass change stops, after which carbonisation is realised at temperature from 400 to 1000°C for 0.5÷12 hours in inert atmosphere or under reduced pressure with formation of highly-disperse initial mixture SiO2-C, from which ceramics is moulded by spark plasma sintering at temperature from 1300 to 2200°C and pressure 3.5÷6 kN for from 3 to 120 min under conditions of dynamic vacuum or in inert medium. Excessive carbon is burned in air at temperature 350÷800°C.

EFFECT: obtaining nanostructured silicon-carbide porous ceramics without accessory phases.

4 cl, 4 dwg, 3 ex

Up!