Diamond-carbon material and preparation method thereof

FIELD: chemistry.

SUBSTANCE: invention can be used at production of finishing compositions, film coatings, radiation-resistant materials. The diamond-carbon material contains the carbon in the form of diamond cubic modification and the X-ray amorphous phase in the mass ratio (40-80):(60-20) respectively; the content of said material is as follows (wt %): carbon 89.1-95.2; hydrogen 1.2-5.0; nitrogen 2.1-4.8; oxygen 0.1-4.7; non-combustible admixtures 1.4-4.8. This material is obtained in enclosed volume, in the gas phase inert to carbon by the detonation of carbon-containing explosive with oxygen deficiency placed into the shell of deoxidant-containing condensed phase with deoxidant/carbon-containing explosive mass ratio not less than 0.01:1. The samples of the obtained diamond-carbon material are prepared for elemental analysis by exposition at 120-140°C under vacuum 0.01-10.0 Pa during 3-5 hrs and following treatment at 1050-1200°C by the oxygen flow with the rate providing their combustion during 40-50 s.

EFFECT: invention allows to obtain the product with high carbon content, predictable properties and ultimate composition in the desired phase state.

4 cl, 1 tbl, 25 ex

 

The technical field

The invention relates to the chemistry of carbon, in particular carbon composite materials containing carbon cubic diamond modification and x-ray amorphous carbon phase, and technologies of their production, in particular detonation methods of producing diamond-carbon material.

Prior art

There are various composite materials obtained by the methods of the detonation synthesis of carbon-containing explosives and containing carbon in different phases.

For example, specialists in the field of chemistry of carbon known condensed carbon (hereinafter KU), which is a composite carbon material containing carbon in a variety of ways and at the same time, depending on the conditions of detonation of carbon-containing explosives, whether or not containing carbon in cubic diamond phase.

This KU can be obtained by detonation of carbon-containing explosives with negative oxygen balance in a special environment that allows you to save condensed carbon products of the explosion (A. I. Lyamkin, Petrov EA, A.P. Ershov, and other Receiving diamonds from explosives, DAN SSSR, 1988, t, s-613; Greiner N.R., Phillips D.S., Johnson F.J.D. Diamonds in detonation soot, Nature, 1988, vol.333, p.440-442; Petrov V.A., G. V. Sakovich, the near Wake PM Us the conditions of preservation of diamonds in the detonation process of obtaining, DAN SSSR, 1990, t, No. 4, s-864; Woodyates. Ultradispersed diamonds of detonation synthesis: properties and application. USP, 2001, t (7), s-708; Woodyates. Ultradispersed diamonds of detonation synthesis, Saint-Petersburg state Polytechnical University, 2003, 344 S.).

It is known that the method of obtaining KU or diamond-carbon material may include undermining charge of carbon-containing explosives in a different environment, for example:

in the gas environment, inert to carbon, such as nitrogen, carbon dioxide, gaseous products of the previous ones (US, 5916955, C1);

- water foam (Petrov V.A., G. V. Sakovich, the near Wake L.M. conservation diamonds in detonation process of obtaining, DAN SSSR, 1990, t, No. 4, s-964);

- when the irrigation charge water (EN, 2036835, C1);

- in a water shell (US, 5353708, C1);

- in ice (EN, 2230702, C1).

Of the existing methods detonation of carbon-containing explosives the most effective from the point of view of the output specifications and the actual diamond modification is undermining charge in a water or ice shell (Woodlots. Ultradispersed diamonds of detonation synthesis. Saint-Petersburg state Polytechnical University, 2003, 344 S.; EN, 2230702, C).

The obtained KU is a nanodispersed carbon powder having specific properties and structure. For example, KU has a high dispersion, the large specific surface area, the presence of the resulting defective carbon structures, high reactivity.

Known synthetic diamond-carbon material (US, 5861349, A), consisting mainly of grouped round and irregular shaped particles in the range of diameters not exceeding 0.1 µ where:

a) elemental composition, wt.%: the carbon of 75.0 to 90.0; hydrogen from 0.8 to 1.5; nitrogen from 0.8 to 4.5; oxygen - to balance;

b) phase composition, wt.%: amorphous carbon from 10 to 30, the diamond cubic modification to balance;

c) the porous structure of the material having a pore volume of 0.6-1.0 cm3/g;

d) the surface of the material with the presence of 10-20% of the surface of methyl nitrite, primary and secondary hydroxyl groups, having different chemical shifts in the spectrum of nuclear magnetic resonance and one or more oxycarboxylic functional groups selected from the group consisting of carbonyl groups, carboxyl groups, quinonoid groups, hydroperoxide groups and Viktorovich groups 1-2% of the surface of the material, associated with the carbon atoms uncompensated bonds; and

e) special surface from 200 to 450 m2/year

While this material is produced by way of the detonation synthesis in the closed volume of the explosive charge containing mainly carbon-containing explosive or mixture of such in the substances having a negative oxygen balance, with the detonation of the charge is initiated in the presence of carbon particles in a concentration of from 0.01 to 0.015 kg/m3in an environment consisting of oxygen from about 0.1 to 6% by volume and a gas inert to carbon, at temperatures from 303 to 363 K (US, 5861349, And). The method is carried out in a pressure chamber with a charge having a negative oxygen balance and consisting mainly of at least one carbon-containing solid explosives.

Famous KU, dubbed "diamond-carbon material" (US, 5916955, A)containing carbon, hydrogen, nitrogen, oxygen, and various non-combustible impurities and containing carbon cubic modification, the carbon x-ray amorphous phase and the crystalline carbon is not the diamond modification in the ratio of phase modifications of carbon, wt.%:

Carbon cubic modification (diamond phase)30-75
X-ray amorphous carbon phase10-15
Carbon crystal modificationsthe rest,

in the following elemental composition, wt.%:

Carbon 84,0-89,0
Hydrogen0,3-1,1
Nitrogen3,1-4,3
Oxygena 2.0 to 7.1
Non-combustible impurities2,0-5,0

The way to obtain this diamond-carbon material (US, 5916955, And includes a stage of detonation of the charge, consisting of carbon-containing explosives in a confined space in an atmosphere containing gas that is inert to carbon, with the formation of detonation products containing carbon cubic modification (diamond phase), x-ray amorphous carbon phase and a crystalline carbon modification. This cooling of detonation products produce with a speed of from 200 to 6000 deg/min, and the atmosphere contains a gas environment containing gases formed in the explosion of the initial charge of carbonaceous substances.

However, the above method for production of diamond-carbon material has a low yield of diamond-carbon material - to 7.8 wt.% and if this is not possible to obtain a material with high efficiency, high quality, because of the low content key in the diamond-carbon material element - carbon - obtained product contains a large number of heteroa the Ohm, mainly oxygen, present in the form of a lactone, ether and aldehyde groups, which leads to too high chemical activity of diamond-carbon material. This fact increases the probability of destructive processes in the compositions with the use of diamond-carbon material, for example, polymer and oil compositions, especially at elevated operating temperatures.

Disclosure of inventions

The aim of the present invention is to develop technology for production of diamond-carbon material with predictable properties and the predicted elemental composition at high carbon content in the desired phase conditions.

In the claimed invention was tasked with the development of the method for production of diamond-carbon material having a high concentration of carbon desired modifications and the desired phase composition of carbon-containing material using a detonation synthesis under conditions that prevent oxidation of the surface of diamond-carbon material and ensure the safety of the obtained diamond phase.

The task was solved by getting a diamond-carbon material containing carbon, hydrogen, nitrogen and oxygen, characterized in that the material contains carbon in the form of a diamond cubic modification and rangeroamer the phase ratio (40-80):(60-20) by weight of carbon, respectively, and contains, wt%:

Carbon89,1 estimates 95.2
Hydrogen1,2-5,0
Nitrogen2,1-4,8
Oxygenof 0.1 to 4.7
Non-combustible impurities0.1 to 1.5

The task was solved by the development of a method for production of diamond-carbon material, including the detonation of carbon-containing explosives with negative oxygen balance in the closed volume in a gaseous environment, inert to carbon, surrounded by condensed phase, characterized in that exercise detonation of carbon-containing explosives placed in the shell of the condensed phase containing a reducing agent in the proportion of the mass of the reducing agent in the condensed phase to the mass of the used carbon-containing explosives is not less than 0.01:1, and receive a product that contains, wt%:

Carbon89,1 estimates 95.2
Hydrogen1,2-5,0
Nitrogen2,1-4,8
Oxygenof 0.1 to 4.7
Non-combustible impurities0.1 to 1.5,the

the mass of carbon containing carbon diamond cubic modification and x-ray amorphous carbon phase in the ratio (40-80):(60-20) wt.%, respectively.

Moreover, according to the invention is suitable as a reductant to use inorganic or organic compound, preferably not containing oxygen atoms and halogen free.

The task was also solved by providing a method of preparing a diamond-carbon material obtained by the method of detonation synthesis of carbon-containing explosives, for subsequent studies to determine the elemental composition, comprising an extract of the specified end product at a temperature of 120-140°C under vacuum of 0.01 to 10.0 PA within 3-5 hours and subsequent treatment at a temperature of 1050-1200°With the flow of oxygen at a speed providing it burning for 40-50 C.

The best option of carrying out the invention

The formation of diamond-carbon material according to the invention by the method according to the invention can be divided into four stages.

1. The first stage of detonation transformation uglerodnom rasego explosives when the explosion occurs mostly within the amount of the charge, limited its outer surfaces, and features of the environment of the charge, does not affect the process of transformation.

Studies have shown that the choice of the composition of the explosives with negative oxygen balance leads to the formation of excess carbon, which remains in a condensed form. Part of this extra carbon in the explosion turns into a diamond cubic modification.

The placement of the charge in the environment in liquid or solid state of aggregation, for example, by undermining the pool filled with water or ice, preventing the expansion of detonation products, creates conditions for increasing duration of existence resulting from the detonation of complex ultra-high pressure and high temperature, which is the range of existence of liquid carbon and diamond.

Accommodation charge inside the shell containing the condensed phase in liquid or solid state of aggregation, for example in the form of water, ice, also allows more time to keep the products of detonation in the amount of the original charge, which leads to a more prolonged the existence of the plasma containing the products of detonation, and contributes to a more complete transfer of "excess" carbon in the diamond phase.

2. In the second stage of transformation, coming after the process is complete detonation, PTS is ery important is ensuring rapid gas cooling of detonation products to save diamond cubic modification, formed in the area of chemical transformations.

It is known that the explosion in vacuum due to the high velocity dispersion, there is a rapid gas cooling of detonation products. However, the subsequent impact of detonation products on the walls of the explosion chamber, their kinetic energy is converted into heat energy, and the temperature in the chamber is growing rapidly, reaching very high values, and after the decay of all shock waves in the cavity of the camera is set to a temperature of ~3500 K, close to the temperature of detonation. And since the pressure in the chamber falls many times faster than the temperature, the diamond cubic modification completely turn (pass) in graphite. Then with prolonged exposure to high temperatures all KU gasified. That is why the explosion in vacuum diamond cubic modification is not saved.

Most slow gas cooling is observed in the expansion of detonation products, surrounded by a massive water or ice shells. The maximum steady-state temperature of detonation products does not exceed 500-800 K due to efficient energy extraction water (EN, 2230702, C; Vaisanen. Macrokinetics save condensed carbon and detonation nanodiamond in a sealed explosion chamber. Solid-state physics, 2004, vol.46, issue 4, s-620).

EOI is output in an inert gas intensity gas cooling takes an intermediate position between the explosion in vacuum and the explosion in the shell of the condensed phase in the form of water or ice, as the speed of expansion of the detonation products in the gas medium is less than in a vacuum, but more than in the presence of water shell or an outer shell.

Since KU is largely determined by the residual temperature in the blast chamber, - the lower the temperature, the higher the output of diamond-carbon material, then it is optimal to use condensed membranes around the charge, creating the greatest cooling.

3. The third stage of detonation synthesis of diamond-carbon material occurs after the reflection of shock waves from the walls of the chamber: circulation of shock waves propagating at supersonic speed, accompanied by processes to dramatically increase the density of the material, pressure and temperature, and turbulent mixing of detonation products with the environment in the cavity of the chamber.

The maximum steady-state temperature of the medium in the cavity of the camera depends on the ratio of the mass of explosive substances and from the composition of the gas environment, i.e. chemical activity environment and the heat capacity of gases.

4. At the fourth stage of the process of detonation synthesis environment heated by the explosion of carbon-containing explosives and limited cold shell, intensively cooled. After the explosion and release of detonation products in the chamber, in addition to different types razoobrazny the x products (CO 2,, O2N2N2CH4, NO, NO2, NH3H2O) is also highly dispersed suspension of particles KU, which have a high emissivity. Therefore, the process of cooling an environment characterized by joint heat transfer by convection and radiation.

It is known that by using the method for measuring the profile of electrical conductivity in detonation wave was found that during the formation of diamond cubic modification does not exceed 0.2-0.5 MS, which corresponds to the width of the zone of chemical reaction in mixed compositions of explosives trinitrotoluene-hexagon, as in injection molding and extruded (Staver A.M., A.P. Ershov, A. I. Lyamkin Study of detonation transformation of condensed explosives by the method of electrical conductivity. Physics of combustion and explosion, 1984, t.20, No. 3, s-82).

As part formed in the first stage of the detonation of solid particles KU turns into gases under the influence generated by the explosion of a gaseous oxidizing agents: CO2N2Oh, CO, O2N2O3, NO2it is possible to talk about "surviving the particle KU, who had not managed to gazifitsiruyutsya, including due to the lack of these gaseous oxidants.

As any unreacted particulate carbon KU have the cover of the function of the national groups, the interaction of surface functional groups with gaseous oxidizing agents are able to change the primary functional groups, including those not containing oxygen, oxygen-containing group, as all oxidants are composed of oxygen.

While using the important function of reducing agent to bind the oxidant, preventing the oxidation of carbon, creates conditions for obstacles oxidizing the surface of carbon particles. This creates the conditions for a substantial increase in carbon content in the diamond-carbon material. This increase is achieved just by reducing the oxygen content, as studies show that the content of hydrogen and nitrogen is changing a little.

It should be noted that the high oxygen content in the diamond-carbon material prevents its effective use in a number of technologies. For example, when using a diamond-carbon material as additives to technical oils, the presence of large quantities of oxygen increases the oxidative capacity of the material.

It is known that detonation of carbon-containing explosives in the gas environment in the conditions established in the cavity chamber temperature of 1500±150 K output RL maximum and equal to ~12%. With the increase in temperature in the cavity of the camera up to 3000-3500 K output KU falls almost on the zero (Vaasana. Macrokinetics save condensed carbon and detonation nanodiamond in a sealed explosion chamber. Solid-state physics, 2004, vol.46, issue 4, s-620).

Preservation of the obtained diamond cubic modification and elemental composition of diamond-carbon material depend on the intensity of flow in the cavity of the camera heterophase endothermic gasification reactions KU carbon dioxide (1) and water vapor (2), which can represent a single gross reaction (3):

At high temperature in the cavity of the camera occur 2 competing processes: gasification KU - first of all, not diamond carbon, as more active, and graphitization formed diamond cubic modification.

Therefore, the authors have found it useful to develop conditions for synthesis, which would provide the minimum possible impact of the detonation products with the detonation of the product and the maximum possible cooling rate of the product to avoid gasification.

According to the invention the introduction of the reducing agent in the composition of the charge condensed shell allows you to achieve multiple effects:

1. The reducing agent prevents the oxidation of the surface of carbon particles on retia stage of the detonation process, linking oxidants as the most chemically active substance in the cavity of the camera. The content of the main hindering subsequent use of KU heteroatoms of oxygen, falls sharply to 0.1%, and it took quite inert and nothing is interfering with the hydrogen. The carbon content increases to 95.2%.

2. Due to partial decomposition of the reducing agent at high temperatures is the temperature drop in the camera, which, in turn, reduces the gasification process (reactions 1-3) and "freezes" phase transition of diamond - graphite.

Thus, the introduction of the reducing agent allows to increase the output SPECIFICATIONS.

The present invention can be illustrated by examples of the method of obtaining the diamond-carbon material according to the invention.

Usually for the synthesis of KU mixed use of carbon-containing explosives, for example a mixture of TNT with RDX or HMX content trinitrotoluene from 30 to 70%. You can use trinitrochlorobenzene mixed with HMX, RDX or TNT.

For testing as the carbon-containing explosives were selected:

- charges from a mixture of TNT with RDX formed by pressing at a pressure of 1500 kg/cm250/50 (examples 1-18) and p is the t in the ratio of 65/35 (examples 19, 20);

- charges from a mixture of TNT and HMX formed by pressing at a pressure of 1500 kg/cm2in the ratio of 60/40 (example 21);

- charges from a mixture of triaminotrinitrobenzene with HMX formed by pressing at a pressure of 1500 kg/cm250/50 (example 22).

The shape of the charge was selected traditional, in the form of a continuous cylinder, the diameter of the cylindrical pieces of 48.5 mm, length of charge 167,1 mm

Undermining charge was performed using the detonator placed at the end of the charge inside it.

The charge of carbon-containing explosives were placed in the shell of their condensed phase, representing a solution of the reducing agent in water in the liquid state of aggregation (examples 1-16, 18, 19, 21, 22) or in the form of ice (example 20), or shell, which is a reservation charge, made of extruded solid reductant (example 17). Thus the weight of the shell was from 4.0 to 6.0 kg, and a shell having a liquid state of aggregation of the condensed phase, consisted of a cylindrical bags made of polyethylene, filled with the condensed phase of the solution of reducing agent, and the charge was suspended (placed) in the center of the bag. In the case of a solid aggregate state of the shell using as reducing agent adamantane shell had the view outside the reservation charge on all surfaces.

As reductants were used dimethylhydrazine (examples 1-5, 19), methenamine (examples 6-10, 20-22), ammonia (examples 11-13), urea (examples 14-16), adamantane (example 17), acetonitrile (example 18) if different, in the range of 0.01 to 10.0):1,0, the ratios of the masses of the used reducing agent and the masses of the used carbon-containing explosives, respectively.

The tests were carried out as follows: the charge in the shell was placed through the top hatch in the explosion chamber, made of stainless steel, of a capacity of 1 m3filled with gaseous products of the previous explosion, the chamber was closed and the charge is undermined.

3 minutes after detonation was carried out by unloading the resulting aqueous suspension of the product through the bottom valve into the receiving tank. The aqueous suspension was passed then through a sieve with a mesh size of 200 μm and dried. The dried product was crushed and sieved through a sieve with a mesh size of 80 μm, and then the samples of the product prepared by the method of preparation according to the invention for carrying out further studies of their elemental composition.

For this purpose, samples of the products obtained was kept at a temperature of 120-140°C under vacuum of 0.01 to 10.0 PA within 3-5 hours and then subjected to treatment at a temperature of 1050-1200°With the flow of oxygen at a speed that provides its burning in t is an increase of 40-50 seconds.

Through research it was found that the diamond-carbon material contains from 8 to 14 wt.% volatiles (mainly water, oxides of nitrogen and carbon). Removal of such impurities is strongly related adsorption forces in the micropores, conventional heating in air at a temperature of 120-125°C is impossible. Increasing the temperature of heating to a higher temperature in the air is dangerous due to decomposition, the possibility of ignition and fire of the diamond particles of carbon.

For complete removal of volatile impurities should be applied vacuum at a residual pressure of 0.01 to 10.0 PA. When this temperature must be maintained in the range of 120-140°C.

When the vacuum of 0.01 PA is sufficient to maintain the temperature of 120°C and at a pressure of 10.0 PA - 140°C. the Pressure is less than 0.01 PA to support impractical for economic reasons, and above 10.0 PA - because of possible incomplete removal of volatile impurities. The temperature rise more than 140°C can cause the collapse of the unstable part no diamond carbon. Warm-up time within 3-5 hours also ensures the complete removal of volatile impurities. At a pressure of 0.01 PA and 120°With enough 3 hours of exposure, and when 10,0 PA and 140°C. it is better to stand for 5 hours.

To determine the elemental composition of diamond-carbon material typically use the standard methods of organic chemistry: the heating temperature is in a stream of oxygen 850-900°C for 5 sec. However, the diamond-carbon material differ in their resistance to oxidation of any organic compounds. Therefore, the above conditions is not sufficient for complete oxidation of the elements of diamond-carbon material. Temperature, ensuring complete combustion (oxidation) of diamond-carbon material is 1050-1200°C, while the warm-up time should be 40-50 seconds. These conditions are achievable, for example, on the device No. 185 produced by Hewlett Packard (USA).

Prepared as described above, the samples of the fusion products were subjected to the following studies:

- research using the method of small-angle scattering to determine the quantitative distribution of the particles according to their size;

- research using polarographic titration to determine the presence and composition of surface oxygen-containing, amine and amide functional groups. This hydroxyl, carboxyl, amine and amide groups are identified by the values of the corresponding regenerative potentials, as well as according to IR-spectroscopy;

- research using gas chromatographic analysis of the presence of surface methyl groups identified on the composition of selected gases when heated at a temperature 663-673 K for 3 hours, the number of allocated methane. the ri data products before gas chromatographic analysis were heated at 473 K in vacuum (0.1 PA) to obtain product constant weight (within 24 hours), while previously adsorbed by the surface of the resulting product is volatile products, including gases were removed and released during gas chromatographic analysis of gases CH4H2, CO2,, O2N2and NH3was the gases generated during the destruction of chemically related KU surface groups;

- research using x-ray photoelectron spectroscopy (XPES) to analyze the distribution of carbon forms in the resulting product;

- research using the method of small-angle scattering (Svergun DI, L.A. Feigin X-ray and neutron small-angle scattering. M.: Nauka, 1986, 280 S.);

- research using the method of determining the specific surface of powders by low-temperature adsorption of nitrogen (hereinafter BET) (Gerasimov YA and the other a Course in physical chemistry. T.1, 2nd edition., M.: Chemistry, 1969, str).

The results are given in the table.

In the research it was found that obtained by the process according to the present invention, the diamond-carbon material is a black powder and has the following options:

- specific surface is from 150 to 550 m 2/g, by using the method of determining the specific surface of powders by low-temperature adsorption of nitrogen (hereinafter BET) (Gerasimov YA and the other a Course in physical chemistry. T.1, 2nd edition repairs., M.: Chemistry, 1969, str),

- average particle size of 2-6 nm, determined using the method of small-angle scattering,

- specific weight in the range of 2.0-2.6 g/cm3.

Content in the resulting product is non-combustible particles, which consists mainly of oxides and carbides of metals, depending on the conditions of detonation synthesis, composition materials of the walls of the explosion chamber and the degree of deterioration of this camera and can range from 1.4 to 4.8 wt.%.

Studies have shown that x-rays has been studied samples of diamond-carbon material contain along with the three lines relating to the diamond phase of carbon, and a broad maximum with d=0,42 nm, related to x-ray amorphous phase of carbon, while the maximum clear outstanding after partial oxidation of CU or oxygen at a temperature of 673 K for 1-5 hours, or when the etching of 98%nitric acid at boiling within 3-8 hours.

The distribution of the particles was studied using the method of small-angle scattering. Studies have shown that the size distribution of particles is characterized by a single maximum in the region between 40 and 60 Å, i.e. narodnye phases are not separated according to particle size.

IR spectra allowed us to identify hydroxyl, carboxyl, carbonyl, amine and amide groups on the surface of the particles KU.

According to gas chromatographic analysis, it was found that when heated in vacuum at 663-673 K within 3 hours of sample product weight 1.0 g there are the following gases:

- methane is 0.12 to 0.60 cm3/g

- hydrogen is only 0.18 to 0.33 cm3/g

- carbon dioxide is 0.01-0,46 cm3/t

- carbon monoxide is 0.01 to 0.13 cm3/g

- oxygen - 0,00-0,02 cm3/g

nitrogen - 0,39-2,04 cm3/g

- ammonia is 0.06 to 0.21 cm3/year

The total gas is 0.82-3,22 cm3/year

On the basis of obtained data we can conclude that the surface obtained KU has the following surface groups: methyl (methane), carboxyl (allocation dioxide and carbon monoxide), amine (ammonia), amide, carbonyl, hydroxyl.

Based on the polarographic titration it was found the presence of carboxyl groups in many samples and carbonyl groups on some samples.

Specialists in the field of chemistry of nanodiamonds it is known that the etching oxidants is layer-by-layer removal of material from the shell particles of diamond-carbon material in the processing of its strong oxidising agents.

Because color the d and hydrogen are concentrated in the upper layers of the particles, then, of course, when layered material removal rate their percentage remaining after etching the particle will decrease, and the percentage of carbon remaining after etching the particle will increase. Because nitrogen is uniformly distributed over the particle, its percentage will not change.

Thus, when any etching oxidants particles of diamond-carbon material, the percentage of nitrogen in the remaining material practically does not change and thus, in contrast to the known diamond-carbon material described above (US, 5916955, A), the nitrogen is fairly evenly distributed across the volume as the diamond phase of carbon, and x-ray amorphous phase of carbon.

On the basis of data given in the table, we can draw the following conclusions:

1. The presence in the membrane of the condensed phase of the reducing agent in amounts of from 0.01 wt.% up to 10 wt.% in relation to the weight used explosives gave a noticeable positive effect, implying a significant change in elemental composition: carbon more of 91.5 wt.%, hydrogen is more than 1.5 wt.%, oxygen is less than 1.5 wt.%, the nitrogen is in the range of 2.2-2.9 wt.%.

The introduction of the reducing agent in a quantity greater than 10 times than the number of explosives, it is impractical for economic reasons. When the ratio of the mass of explosives to passivestances 1:10.0 release of KU and its carbon content cubic modification reach maximum values, and a further increase in the quantity of reducing agent will lead to technical difficulties in extraction of diamond-carbon material of the camera and its processing.

Physico-chemical properties of diamond-carbon material obtained by the method according to the invention can be used as a nano-component high-performance composite materials.

Comparative tests using a diamond-carbon material obtained in various ways.

If it were made of butter for submersible oil pumps, in which additives were used:

A) a diamond-carbon material obtained by the process according to the invention, having the following composition, wt.%: carbon 94.5%of hydrogen is 1.2%, the nitrogen 2.5 %, oxygen - 0,8%, non-combustible impurities to 1.0% when the content of carbon in the diamond cubic modification (72%) and x-ray amorphous carbon modification - 28%.

B) diamond-carbon material obtained by the method of detonation, described above (US, 5916955, A)having the following composition, wt.%: carbon and 88.8%, hydrogen - 1,1%, nitrogen - 3.1%, oxygen of 4.9%, non-combustible impurities is 2.1%, with the content in weight of carbon: carbon in the diamond cubic phase is 42% and in other forms of carbon - 58%.

The results of comparative tests showed that the use of oils with additives of the mater is Ala B in submersible oil pumps in a closed loop of Mesopotamia led to a complete resinification oil for 18 hours and the failure of the pump due to a catastrophic wear of the surfaces.

Use oils with additives from the material And this invention does not cause resinification of oil and condensation (sticking together) of the diamond particles with subsequent surface wear.

Thus, the diamond-carbon material according to the invention obtained by the method of detonation synthesis according to the invention, have improved elemental and phase composition in comparison with the known diamond-carbon material, which leads to more stable and predictable properties of the compositions and materials when they are used in various fields of science and technology.

Samples of the resulting diamond-carbon material prepared by the method of preparation according to the invention then determine its elemental composition.

Examples of specific performance.

Example 23. Diamond-carbon material obtained by the method of detonation synthesis of carbon-containing explosives in example 1, or 3, or 15, is maintained at a temperature of 120°C under vacuum 10,0 PA within 3 hours, and then treated at a temperature of 1050°C. the oxygen flow with speed, providing his burning within 40 C.

Example 24. Analogously to example 23. Use the diamond-carbon material obtained in example 4, or 7, or 20. Ageing conditions of a temperature of 140°C., a vacuum of 0.01 PA, the time is 4 hours. Subsequent treatment is otcu material is carried out at 1200°C by a stream of oxygen at a speed providing his burning within 50 C.

Example 25. Analogously to example 23. Use the diamond-carbon material obtained in example 9, or 19, or 22. Ageing conditions of a temperature of 130°C., a vacuum of 1 PA, the time - 5 hours. Subsequent processing of the material is carried out at 1100°C With a flow of oxygen at a speed that provides its burning within 45 C.

Industrial applicability

Diamond-carbon material according to the invention can find wide application in various technologies, such as polishing-finishing compositions, film coatings, the composition of the radiation-resistant materials.

Diamond-carbon material according to the invention can be obtained by the process according to the invention, which can be implemented using existing manufacturing equipment and known explosives.

1. Diamond-carbon material containing carbon, hydrogen, nitrogen and oxygen, characterized in that it contains carbon in the form of a diamond cubic modification and x-ray amorphous phase in the ratio (40-80):(60-20) by weight of carbon, respectively, and contains, wt%:

Carbon89,1 estimates 95.2
Hydrogen1,2-5,0
Nitrogen/td> 2,1-4,8
Oxygenof 0.1 to 4.7
Non-combustible impurities1,4-4,8

2. A method for production of diamond-carbon material, including the detonation of carbon-containing explosives with negative oxygen balance in the closed volume in a gaseous environment, inert to carbon, surrounded by condensed phase, characterized in that exercise detonation of carbon-containing explosives placed in the shell of the condensed phase containing a reducing agent in the proportion of the mass of the reducing agent in the condensed phase to the mass of the used carbon-containing explosives is not less than 0.01:1, the product obtained contains, wt%:

Carbon89,1 estimates 95.2
Hydrogen1,2-5,0
Nitrogen2,1-4,8
Oxygenof 0.1 to 4.7
Non-combustible impurities1,4-4,8,

and in the mass of carbon contains carbon in the diamond cubic modification and plastics technology : turning & the d in the x-ray amorphous phase in their relationship (40-80):(60-20) wt.% respectively.

3. The method according to claim 2, characterized in that as the reductant use inorganic or organic compound having reducing properties, is preferably not containing oxygen atoms and halogen free.

4. The method of preparation of diamond-carbon material obtained by the method of detonation synthesis of carbon-containing explosives, and then determine its elemental composition, comprising an extract of the specified diamond-carbon material at a temperature of 120-140°C under vacuum of 0.01 to 10.0 PA for 3-5 h and subsequent treatment at a temperature of 1050-1200°With the flow of oxygen at a speed providing it burning for 40-50 C.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: present invention relates to chemical engineering, and to high-pressure technology of making diamonds, particularly for growing large crystals, the process of which is long. The high-pressure apparatus has a multiple-punch unit, which is enclosed in a sealed elastic casing 6. In the first version the multiple-punch unit is fitted on a sealed hollow platform 1, which has at least two sealed cavities 10, at least one of which is linked through a valve with the external environment for filling with water when submerged. In the second cavity there is a motor 11, with a pump for pumping water from the first sealed cavity when raising the apparatus. In the second version the sealed cavities can be made in the sealed hollow platform and in one of the punches. In the third version the sealed cavities can be made in at least two punches of the multiple-punch unit.

EFFECT: no use of load-carrying structures and compressors in the apparatus due to the possibility of using natural water column pressure, created by the Earth gravitational field.

15 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: carbon-containing explosive with negative oxygen balance is placed in a shell of condensed phase including reduction agent. Mass ratio of reduction agent to carbon-containing explosive is not less than 0.01:1. Detonation is performed in closed volume in gas medium inert to carbon. Detonation product is processed by 2-40% aqueous nitric acid together with oxygen of compressed air at 200-280°C and pressure of 5-15 MPa. Obtained nanodiamond includes carbon of cubic diamond modification and roentgen-amorphous phase at the ratio of (82-95):(18-5) wt % respectively. Element composition of nanodiamond, wt %: carbon 90.2-98.0; hydrogen 0.1-5.0; nitrogen 1.5-3.0; oxygen 0.1-4.5.

EFFECT: improved process safety, obtaining nanodiamond with predictable properties at industrial scale.

3 cl, 5 tbl

FIELD: chemistry.

SUBSTANCE: present invention can be used in making a cutting and a machining tool and electrodes. The sintered diamond object with high strength and high wearing resistance contains 80-98 vol.% particles of sintered diamond, with average size of not more than 2 mcm, and a phase of binding substance, containing 50-99.5 wt % cobalt and 0.5-50 wt % of at least one element, chosen from a group comprising Ti, Zr, Hf, V, Nb, Ta, Cr, Mo. Part of the element or weight of the element is in form of carbide particles, with average size of not more than 0.8 mcm. The texture of carbide particles is non-continuous, and adjacent diamond particles are bonded together. Sintering is carried out at 5.7-7.5 GPa pressure and 1400-1900°C temperature in a "belt" type super-high pressure device.

EFFECT: provision of transverse breaking strength of not less than 2,65 GPa, excellent wearing resistance, resistance to shearing, shock resistance and thermal conductivity.

7 cl, 6 tbl, 5 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: mixture from source of carbon - graphite and metal-solvent based on nickel-manganese alloy in ratio 40:60 of weight respectively is prepared. 3.73-33.55 wt % of manganese carbide powder Mn7C3 and 2.27-20.45 wt % of nickel powder are introduced into mixture on condition that ratio of nickel and manganese in metal-solvent is preserved. Obtained charge is pressed into tablets, put into alundum crucible and thermally processed in vacuum.

EFFECT: increase of diamond crystals output and increase of grainularity part without using expensive inoculating diamond crystals.

1 tbl

FIELD: chemistry, technological processes.

SUBSTANCE: invention allows to obtain memorial diamond from pale-yellow to light-blue tint depending on content of admixture in it, which is identified with exact person and is an object, which reminds of him/her. Method includes processing of biological material belonging to exact individual, and growing on its basis artificial diamond by acting on it with high pressures and temperatures. Processing is performed by mechanical grinding, preliminary drying, chemical processing in hydrochloric acid, chemical processing with complex-former Trilon-B, chemical processing with mixture of mineral acids - hydrofluoric and nitric or sulfuric acids, repeated washing after each chemical processing with said reagents to neutral reaction, filtration and drying until pure highly-dispersive carbon of biological origin is obtained.

EFFECT: obtaining carbon of high purity with characteristic microelements for exact individual.

6 cl, 3 tbl

FIELD: technological processes.

SUBSTANCE: initial substance 2 is heated by exothermal reaction of termite mixture 3 combustion, which contains catalyst, exposed to shock pressure created with blasting charge 5, and cooled on separate metal surface, which is made in the form of tube 1. Blasting charge 5 is installed around tube 1. Initial substance 2 is used in the form of geometric reflection of tubular cavity, and thermite mixture 3 is placed around it. Impact of shock pressure is carried out after heating of initial substance, its displacement into tubular cavity and its filling.

EFFECT: increase of diamonds output and reduction of power inputs and blasting charge consumption.

2 dwg

FIELD: technological processes.

SUBSTANCE: invention claims diamond tool manufactured with monocrystallic diamond, synthesised under high pressure by temperature gradient method, so that the claimed diamond crystal contains not more than 3 parts per million of nitrogen. The tool features a blade with its edge oriented in plane (110), so that Knoop scale hardness at the plane (100) in direction <110> is higher than in direction <100>. Such synthetic monocrystallic diamond is synthesised by temperature gradient method under superhigh pressure and high temperature, and its crystals contain nickel atoms introduced by atomic substitution or boron and nickel atoms introduced by atomic substitution.

EFFECT: obtaining cheap synthetic monocrystallic diamonds with reduced flaw number.

24 cl, 4 ex, 2 tbl, 7 dwg

FIELD: technological processes.

SUBSTANCE: invention may be used for production of parts and cutting tools for processing of wear resistant materials, in particular, silicon-containing aluminium alloys. Layers of diamond powder and material of impregnation that are in contact are placed layer by layer on charge. Layer of diamond powder is divided into two layers. In one of the layers, which contacts with impregnation material, diamond powder is used with size of particles from 20/14 to 2/1 mcm. Additionally detonating diamond powder is introduced with size of particles in the range from 1 to 100 nanometers in the amount from 1 to 30 percents from the volume of diamond powder of this layer. In the second layer, which contacts the first one, diamond powder is used with size of particles in the range from 40/28 to 28/20 mcm, at that height of this layer in respect to the first one amounts from 2:1 to 3:1. As impregnation material silicon or silicon-containing materials are used, for example, mixture of silicon powders, flaked graphite and detonating diamond. Stock prepared by this method is affected with high pressure - from 3 to 8 GPa and temperature of 1200 - 2000°C, for 40 - 120 sec. Prior to effect of high pressure and temperature stock may be shaped in round, square, rhombic, triangular, hexagonal and other forms. Ultrahard compact is prepared with high cutting ability and output of serviceable products.

EFFECT: permits to provide high purity of processed materials surface.

2 cl, 2 dwg, 1 tbl, 6 ex

FIELD: blasting.

SUBSTANCE: blasting chamber comprises a vertically mounted cylindrical shell with bottoms, an access door and means for securing an explosive charge inside the chamber. The chamber is made of steel-plated reinforced concrete, the chamber walls contain pipes being evenly distributed over the chamber inner surface. The centrelines of said pipes are directed to the centre of the chamber, wherein the pipes are connected with air-tight water tanks that are connected with a compressed air receiver through solenoid valves, wherein the chamber bottoms have a conical shape and in the centre of each bottom there is an expander having the shape of a cylinder or a polygon, on the side face of which there is a door for loading a charge into the chamber and discharging explosion solid products. Said means for securing the explosive charge have the form of a steel wire rope extending along the chamber centerline and capable of moving, lifting and holding the charge by means of an electric hoist mounted on the top expander bottom and of a section wire, one end of which is attached to the wire rope, and another - to the charge.

EFFECT: improving the efficiency of the chamber; safety and ease of its use requiring no personnel entry inside the chamber.

2 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: process of hard monocrystalline diamond preparation compises fixing of inoculating diamond in the holder and its growing by the way of chemical deposition from gaseous phase induced by microwave plasma. The process is implemented at temperature ca 1000°C - 1100°C in medium N2/CH4=0.2-5.0 and CH4/H2=12-20% at total pressure 120-220 torr. Derived monocrystalline diamond has the hardness in the range 50-90GPa and fracture strength 11-20MPa m1/2.

EFFECT: increasing of diamond hardness.

7 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to the catalytic systems based on gold; usage of nanometric gold precipitation by the condensation from vapour phase to the activated carrier; system of breathing organs defence using aforesaid catalytic systems. The method of heterogenous catalytic system making is described including: 1) condensation from vapour phase of the catalytically active gold clusters with dimensions in the range from 0.5 to 50 nm to the nanoporous carrier; 2) the following stages: (a) impregnation of water-soluble salt to the catalyst nanoporous carrier; (b) thermic treatment of the said impregnated carrier at temperature more than approximately 200°C; (c) condensation from vapour phase of the catalytically active gold clusters with dimensions in the range from 0.5 to 50 nm to the said thermically treated nanoporous carrier; 3) following stages: a) aggregation of the relatively small particles multifold and of the relatively large particles multifold to the multifold of nanoporous composite particles; b) precipitation of catalytically active gold clusters with dimensions in the range from 0.5 to 50 nm gold clusters to the said composite particles by the condensation from vapour phase. The described heterogenous catalytic system contain: 1) nanoporous carrier; at least one water-soluble salt impregnated to the said carrier; clusters of catalytically active gold with dimensions in the range from 0.5 to 50 nm precipitated on the said carrier with the penetration depth index in the range from ca 1×10-9 to ca 0.1; 2) multifold of the composite catalytically active particles characterised in that said catalytically active particles are obtained from the components containing relatively small particles and relatively large particles with said composite particles containing catalytically active gold precipitated on the relatively small particles by the condensation from vapour phase. The system of breathing organs defence including any of aforesaid heterogenous catalytic systems is described.

EFFECT: invention provides essential improvement of the method of gold-containing catalytic systems preparation and enhancing of their characteristics.

22 cl, 71 ex, 4 tbl, 58 dwg

FIELD: physics.

SUBSTANCE: invention is related to micro- and nanoelectronics and may be used in production of integral silicon chemical and biosensors for automated control of environment, in ecology, in chemical production, in biology and medicine. Invention is aimed at reduction of nanosensor size, reduction of defectiveness, increased sensitivity, repeatability and efficiency, achievement of compatibility with standard industrial technology VLSI. In method for manufacture of nanosensor, which consists in the fact that dielectric layer is created on silicon substrate, and on surface of dielectric layer silicon layer is formed, from which nanowire with ohm contacts is formed via mask by etching, etching for formation of nanowire with ohm contacts of specified size is carried out in vapours of xenon difluoride with the rate of 36÷100 nm/min, at temperature of 5÷20°C, for 0.3÷1.3 min., silicon layer, from which nanowire is formed with ohm contacts by etching, is created with thickness of 11÷45 nm, and etching mask used is mask of polymer polymethyl methacrylate with thickness of 50÷150 nm.

EFFECT: reduction of nanosensor size, reduction of defectiveness, increased sensitivity, repeatability and efficiency, achievement of compatibility with standard industrial technology VLSI.

3 dwg

FIELD: physics, semiconductors.

SUBSTANCE: invention is related to methods for creation of metal nanowires on surface of semiconductor substrates and may be used in creation of solid-state electronic instruments. Substance of invention: in method for creation of conducting nanowires on surface of semiconductor substrates, copper is deposited on surface of silicon Si(lll) with formation of buffer layer of copper silicide Cu2Si at the temperature of 500°C under conditions of ultrahigh vacuum. Buffer layer of copper silicide is formed with monatomic thickness, afterwards at temperature of 20°C at least 10 layers of copper are deposited on atomic steps of buffer layer surface, which form nanowires of epitaxial copper that are oriented along atomic steps of substrate.

EFFECT: provides for creation of nanowires that possess high conductivity, with the possibility of these nanowires formation location control.

3 dwg

FIELD: chemistry.

SUBSTANCE: method includes heating of silica oxide photon crystals with modifying agent - crystal phosphor cesium iodide in vacuum at temperature not less than 800°C during not less than 15 hr. Cesium iodide can be activated with different admixtures (Na, Tl, In, CO3 etc), providing more bright (in comparison with pure CsJ) radioluminescence on the different waves of the visible-light spectrum. Usage of the scintillator - cesium iodide as filler provides good wettability (caused by capillary forces) of silica oxide microspheres with the melted cesium iodide without outer pressure. It allows to obtain optically inverted composite having approximately the same optical contrast (ratio of the refractive indexes relating to microspheres medium and to the medium filling the pores between microspheres) as initial silica oxide has.

EFFECT: obtaining of the end product with high yield.

4 cl, 1 ex, 2 dwg

FIELD: production processes.

SUBSTANCE: in compliance with the proposed method, copper matrix is pressed at 100 to 300 MPa and sintered at 5640 to 680°C for 1 to 2 h in protective-reducing gaseous atmosphere to produce apparent-porosity structure. Nonstructural component is introduced therein in vacuum impregnation of the matrix with suspension of refractory material nanoparticles in glycerin-based protective fluid at 1 to 10 kPa. Aforesaid protective fluid is removed at 80 to 95% of its boiling point. Finally, final sintering is effected at 810 to 1020°C for 1 to 2 h in protective-reducing gaseous atmosphere.

EFFECT: simplified process, expanded technological performances, improved physical-mechanical properties.

3 cl, 1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: prealloyed powder is received by means of mechanical activation of powders mixture of initial components at temperature, not exceeding 150°C, up to formation in powder of nanostructural and/or amorphous state. Directly after the activation it is implemented pressing at pthe pressure not less than 510 MPa at oom temperature or 0.2 Tmelt or, where Tmelt - melting temperature of the lowest melt component of powder composition, or at crystallisation temperature of amorphous phase.

EFFECT: increasing of density, strength with keeping of peculiarities of structural condition, received at mechano-chemical synthesis.

1 tbl, 2 ex

FIELD: physics.

SUBSTANCE: proposed laser material is a ceramic polycrystalline microstructure substance with particle size of 3-100 mcm, containing a twinned nanostructure inside the particles with size of 50-300 nm, made from halides of alkali, alkali-earth and rare-earth metals or their solid solutions, with vacancy or impurity laser-active centres with concentration of 1015-1021 cm-3. The method involves thermomechanical processing a monocrystal, made from halides of metals, and cooling. Thermomechanical processing is done until attaining 55-90% degree of deformation of the monocrystal at flow temperature of the chosen monocrystal, obtaining a ceramic polycrystalline microstructure substance, characterised by particle size of 3-100 mcm and containing a twinned nanostructure inside the particles with size of 50-300 nm.

EFFECT: improved mechanical properties, increased microhardness and failure viscosity.

5 cl, 1 tbl, 4 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: method involves chemical reduction of noble metal ions from an aqueous solution of its compound with a reducing agent being anionic polyelectrolyte and noble metal ions concentrated 0.1-5 mg-ion/dm3 and polyelectrolyte concentrated 5-350 mg/dm3. The process is intensified due to temperature rise within 20-60°C and/or light exposure 500-3000 lux.

EFFECT: invention allows for nano- and micro- monocrystals in free liquid volume without sol particle impurity while maintaining the size within specified range.

9 cl, 12 ex, 1 tbl, 5 dwg

FIELD: technological processes.

SUBSTANCE: during manufacture of structured surface wood grain pattern is applied on board surface (2) by means of printing method, then the first partially optically transparent coating (22) from varnish is applied on wood grain pattern. Using method of direct or indirect printing, the first coating is coated with partially optically transparent second coating (24) from varnish with spatially varied distribution of applied substance amount so that the second layer creates negative surface structure, in which surface structures that actually imitate indents are created in the form of elevations (28).

EFFECT: provides for improvement of surface structure.

39 cl, 11 dwg

FIELD: chemistry.

SUBSTANCE: present invention can be used in pharmaceutical, food, chemical and electronic industry when making catalysts, polymers, pesticides and coatings. An aqueous solution of micronised substance is poured from container 6 into a high pressure cell 5. Using a high pressure pump 2, carbon dioxide is fed from cylinder 1 into booster cylinder 4 and cell 5 until attaining pressure in the range of 90-400 atm. Temperature in booster cylinder 4 and cell 5 is kept in the range of 33 - 160°C. The obtained two-phase system (aqueous solution of substance/carbon dioxide) is dispersed through a spray nozzle 10 at 100-200°C temperature. Supercritical carbon dioxide acts as the "plunger". Nano- and micro-sized particles formed in the dispersion chamber are trapped in separator 8.

EFFECT: invention allows for obtaining aerosols and powders of water soluble substances of nano- and micro-sizes without using harmful organic solvents.

3 cl, 4 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: carbon-containing explosive with negative oxygen balance is placed in a shell of condensed phase including reduction agent. Mass ratio of reduction agent to carbon-containing explosive is not less than 0.01:1. Detonation is performed in closed volume in gas medium inert to carbon. Detonation product is processed by 2-40% aqueous nitric acid together with oxygen of compressed air at 200-280°C and pressure of 5-15 MPa. Obtained nanodiamond includes carbon of cubic diamond modification and roentgen-amorphous phase at the ratio of (82-95):(18-5) wt % respectively. Element composition of nanodiamond, wt %: carbon 90.2-98.0; hydrogen 0.1-5.0; nitrogen 1.5-3.0; oxygen 0.1-4.5.

EFFECT: improved process safety, obtaining nanodiamond with predictable properties at industrial scale.

3 cl, 5 tbl

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