Method of obtaining carbon nano-tubes
SUBSTANCE: invention relates to microstructural technologies, namely to nanotechnology, in particular, to method of obtaining fibrous carbon nanomaterials which consist from carbon nano-tubes, by method of precipitation from gas phase. Reactor is filled with inert gas and its central part is heated. Then reaction mixture containing carbon source and ferrocene catalyst source is injected, which under impact of temperature turns into vapour. Vapour is kept in hot zone by ascending inert gas flow, source of padding for precipitation of catalyst nanoparticles and growth of carbon nano-tubes being introduced into reaction mixture. As padding source used are complexes of macrocyclic polyesters with salts of metals selected from line Ca, Ba, Sr, Y, Ce, which have temperature of decomposition lower than catalyst source, and serve as continuous source of padding.
EFFECT: synthesis of carbon nano-tubes is performed continuously, which results in increase of carbon nano-tubes output.
1 dwg, 3 ex
The invention relates to a microstructure technologies, namely nanotechnology, in particular to a method for producing fibrous carbon nanomaterials consisting of carbon nanotubes by chemical vapor deposition from the gas phase.
The known method of synthesis of carbon nanotubes by chemical vapor deposition from the gas phase, in which a pair of the original carbon-containing substances are served in a chemical reactor, in the hot zone (500-600°C) is specially prepared catalyst of nanoparticles of transition metals group (Fe, Ni, or Co) (Kuvshinov G.G., Zavarukhin YEAR, Burial SCI, Jugs became popular: "the Implementation of the process for obtaining granular catalytic filamentous carbon in the pilot scale reactor", Chemical industry, 1998, No. 5, p.48.) The source of gaseous carbon compounds interact with the catalyst, leading to the formation of a fibrous carbon material.
The disadvantage of this method of synthesis of carbon nanotubes is the need for a specially prepared catalyst having a limited period of time, the need to stop the process of synthesis to download a new portion of the catalyst. The disadvantages of such a method can also include the fact that the obtained carbon material with the consists of threads, having a considerable range of variation in the diameters (from 10 to 150 nm).
The closest way to produce carbon nanotubes, selected as a prototype, is the way in which the catalytic nanoparticles are formed during the synthesis process in the decomposition of ferrocene dissolved in the original carbonaceous substance (xylene, heptane, acetonitrile, ethanol and others). A pair of reaction mixture (solution of ferrocene in the carbon-containing substance) served in a chemical reactor with a flow of inert gas or by using a special injector that allows you to inject the aerosol reaction mixture into the hot zone of the reactor (A.G. Kudashov, Kuren A.G. Okotrub AV, Guselnikov, A.V., D. B.C., Bulusheva L.G.: "Synthesis and structure of films of carbon nanotubes oriented perpendicular to the substrate", Journal of technical physics, 2007, volume 77, VIP, p.96). In an inert atmosphere at a temperature of 700-900°C the decomposition of the original reaction mixture to form on the internal surfaces of the reactor layer of iron nanoparticles, which serve as a catalyst for growth of carbon nanotubes. The material, consisting of carbon nanotubes is formed on the inner surfaces of a chemical reactor or at a specially arranged therein silicon substrates.
However, the disadvantage of this method is the bottom of the s, the yield of carbon nanotubes, since in this method, the formation of catalytic particles on the surface and not in the reactor volume, therefore, the growth of carbon nanotubes occurs only on the inner walls of the reactor or on the substrate, the surface of which is in the process of synthesis is covered with a layer of the obtained carbon material and becomes unavailable for the formation of new catalytic particles, which leads to the cessation of growth of carbon nanotubes. The result requires mechanical removal of the formed material with the inner surface of a chemical reactor or substrate, which makes it impossible for the continuous synthesis and the production of the material ineffective.
The objective of the invention is to provide a process for making synthesis of nanotubes continuous, less time consuming, as well as to increase the yield of carbon nanotubes.
The problem is solved in that in the method of producing carbon nanotubes by chemical vapor deposition, comprising filling the reactor with an inert gas, heating the Central part of the reactor, the injection of the reaction mixture containing a source of carbon source and ferrocene catalyst, which under the action of temperature into steam, the steam is kept in the hot zone of the upward flow of inert gas, in the reaction mixture in the W ill result source substrate for deposition of nanoparticles of catalyst and growth of carbon nanotubes, at the same time as the source substrate using complexes of macrocyclic polyethers with salts of metals selected from the range of CA, BA, Sr, Y, CE, which have a decomposition temperature lower than a source of catalyst, and serve as a continuous source substrate.
Distinctive features of the proposed method: introduction source substrate in the reaction mixture together with other reagents, carrying out the method in an upward flow of inert gas.
Introduction in the reaction mixture in addition to a carbon source and a source of catalyst, substance that forms during decomposition in the gas phase particles serving as substrate for the deposition of nanoparticles of catalyst that promotes the growth of carbon nanotubes from the gas phase. Formed on the particle-substrate iron nanoparticles catalyze the growth of carbon nanotubes from the gas phase according to the mechanism of carbide cycle, in which carbon from the gas phase is dissolved in the particles of the metal catalyst, reaching a maximum value of the concentration at a given temperature and is released in the form of a solid phase on the surface of the catalytic nanoparticles. Effect of geometrical and thermodynamic characteristics of the solid phase of carbon is formed in the form of a hollow cylinder or tube. This process occurs continuously until the erosion of the catalyst and the and termination of access to the surface of the catalyst vapor source of carbon-containing substances.
As such substances selected complexes of macrocyclic polyethers with salts of metals selected from the range of CA, BA, Sr, Y, CE. Feature of high-macrocyclic compounds is a good solubility in water and other solvents, relatively low decomposition temperature lower than that of the source of catalyst is ferrocene, i.e. their decomposition occurs before the decomposition of the source of catalyst. Decomposing at lower temperatures in a stream of inert gas, these complexes form spherical particles with a diameter in tenths of a micrometer. Moving in a stream of inert gas, the particles increase in size and when it enters the zone with higher temperature become a substrate for the deposition of smaller catalytic particles of iron, resulting from the decomposition of ferrocene (~480°C). Entering the reactor continuously, together with pairs of the original carbon-containing substance and a source of catalyst complexes of macrocyclic polyethers, decomposing at higher temperatures, serve as a continuous source of substrate required for the deposition of catalytic nanoparticles and, consequently, growth of carbon nanotubes, making the process continuous. Conducting the process in an upward flow of inert gas allows decayed reaction mixture to contain the reaction zone for a long time, what contributes to growth of nanotubes in the reactor volume.
Thus, first, the formation and growth of carbon nanotubes with inner surfaces of the reactor is transferred to its volume, increasing share of the working surface of the reactor, and secondly, while filing source substrate with a carbon source and a source of catalyst makes the process of synthesis is continuous, and the reactor is more efficient.
The drawing shows a micrograph of a fibrous material consisting of carbon nanotubes, obtained using scanning electron microscope JEOL 20070 F. the drawing shows that the material consists of carbon nanotubes with a diameter of ~70-80 nm, chaotically intertwined in the balls. The drawing clearly traced the centers of which is the growth of multiple carbon nanotubes.
To prepare the reaction mixture in 100 ml of ethanol was dissolved 0.5 g of ferrocene and 0.5 g of crown ether calcium CA(NO3)2C (1,4,7,10,13-intoxication). After filling the reactor with an inert gas into the volume of the reactor, the Central portion of which is heated to a temperature of 850°C, injected in the form of aerosols reaction mixture. Injection of 100 ml of the reaction mixture is carried out for 2 hours. Under high temperature, the reaction mixture turns into steam, which is the first for some time held in the hot zone of the upward flow of inert gas, supplied with a constant velocity in the lower part of the vertical tubular reactor. Decomposition of the reaction mixture crown-ether calcium, included in its composition, forms particles of calcium on the surface of which the decomposition of ferrocene is the deposition and formation of iron nanoparticles that serve as a catalyst for growth of carbon nanotubes from the gas phase, where the ethanol acts as a carbon source. With the growth of the nanotubes particles become heavier and increase in volume, deposited in the lower part of the reactor, forming a black substance, consisting of intertwined carbon nanotubes, which is removed from the reactor through a special gateway. When the injection of 100 ml of the reaction mixture for two hours produces 40-50 g of material, consisting of carbon nanotubes with a diameter of ~70-80 nm, which is 50-65% by weight of the original substance.
To prepare the reaction mixture in 100 ml of heptane was dissolved 0.5 g of ferrocene and 0.5 g of crown ether Sr (NO3)2C (1,4,7,10,13-intoxication). The process is identical to the one described in example 1.
When the injection of 100 ml of the reaction mixture formed 45-55 grams of material, consisting of carbon nanotubes with a diameter of ~40-50 nm, which is 65-80% by weight of the original substance.
To prepare the reaction mixture in 100 ml of t is clohexane dissolve 0.35 g of ferrocene and 0.05 g of crown ether calcium Ca(NO 3)2C (1,4,7,10,13-intoxication). The process is identical to the one described in example 1 at a temperature of 750°C. During injection of 100 ml of the reaction mixture formed 35-40 g of material, consisting of carbon nanotubes with a diameter of ~30-40 nm, which is 65-80% by weight of the original substance.
Method of producing carbon nanotubes by chemical deposition from the gas phase, comprising filling the reactor with an inert gas, heating the Central part of the reactor, the injection of the reaction mixture containing a source of carbon source and ferrocene catalyst, which under the action of temperature into steam, wherein the steam to remain in the hot zone of the upward flow of inert gas, in the reaction mixture entering the source of substrate for the deposition of nanoparticles of catalyst and growth of carbon nanotubes, as a source of substrate use complexes of macrocyclic polyethers with salts of metals selected from the range of CA, BA, Sr, Y, CE, which have a decomposition temperature lower than a source of catalyst, and serve as a continuous source substrate.
SUBSTANCE: invention relates to method for control and simulation of compaction of at least one porous substrate with pyrolitic carbon by chemical gas phase infiltration. According to the method, a lot of one or several substrates to be compacted is placed into furnace, the said substrate is heated, reaction gas containing at least one carbon-source hydrocarbon is supplied to the furnace, pressure, at which reaction gas is capable to diffuse into the heated substrate pores with formation of pyrolitic carbon residue, is established in the furnace, and waste gas is released from the furnace via exhaust pipe connected to the furnace outlet. In waste gas, content of at least one substance chosen from allene, propyne and benzene is determined. According to measured content, process is controlled by setting at least one of the following parameters: flow rate of reaction gas supplied to the furnace, flow rate of at least one component of gas supplied to the furnace, time of gas transit through the furnace, substrate temperature and pressure inside the furnace. At least one of parameters is set so as to provide for almost constant measured gas content. Compaction process can be either controlled in real time or simulated.
EFFECT: possibility of real-time control and simulation of process of compaction of at least one porous substrate with pyrolitic carbon using chemical gas phase infiltration.
12 cl, 8 dwg, 8 tbl, 10 ex
FIELD: technological processes.
SUBSTANCE: electrode that surrounds the receptacle and forms part of pressure reduction chamber intended for receptacle installation and electrode that is installed next to receptacle neck above its opening are installed one opposite to each other and separated with insulating body. This body forms part of pressure reduction chamber. Inlet tube of gas is made of insulating material for guiding gas that is supplied to the mentioned chamber with the help of supply facility of gas that is transformed into plasma for application of diamond-like film of coating onto receptacle wall internal surface. Tube is installed on facility for exhaust of gas that is available in pressure reduction chamber from the bottom part of receptacle part with opening. High-frequency supply facility is connected to electrode that surrounds receptacle, therefore, it is possible to freely ignite plasma and execute discharge.
EFFECT: stabilisation of plasma discharge and prevention of dust adhesion to electrode.
16 cl, 12 dwg, 2 ex, 2 tbl
SUBSTANCE: invention refers to plastic package with inside surface of wall coated with diamond-like film; invention also refers to device for fabricating this package and to method of package fabricating. The device contains an electrode encompassing the package and forming one portion of a chamber for pressure fall where the package and a facing electrode located inside the package above an aperture are arranged. The said electrodes face each other and are divided with an insulating body forming portion of the pressure fall chamber. A device for source gas supply contains an inlet pipe of supplied gas. There are also a pumping out device and a device of high frequency supply. The method includes pumping out the package contents till achieving the pressure less or equal to specified, then introduction of source gas for generating plasma, termination of pumping out and decreasing the rate of introduction of the source gas to the value less than the rate of introduction at the moment of change, generating plasma for formation of diamond-like carbon film on the interior surface of the plastic package wall. Thus the package with film is produced; the said film has equal level of oxygen impenetrability; and colouring of film formed at the throat portion of the package is avoided.
EFFECT: production of package with diamond-like carbon film with uniform level of oxygen impenetrability.
25 cl, 24 dwg, 7 tbl
FIELD: carbon particles.
SUBSTANCE: invention relates to technology of preparing particles having monocrystalline diamond structure via growing from vapor phase under plasma conditions. Method comprises step ensuring functioning of plasma chamber containing chemically active gas and at least one carbon compound and formation of reactive plasma, which initiate appearance of seed particles in the plasma chamber. These particles ensure multidirectional growing of diamond-structured carbon thereon so that particles containing growing diamond are formed. Functioning of plasma chamber proceeds under imponderability conditions but can also proceed under gravitation conditions. In latter case, seed particles and/or diamond-containing particles in reactive plasma are supported under effect of external gravitation-compensating forces, in particular by thermophoretic and/or optic forces. Temperature of electrons in the plasma are lowered by effecting control within the range from 0.09 to 3 ev. Chamber incorporates plasma generator to generate plasma with reduced electron temperature and device for controlling forces to compensate gravitation and to allow particles to levitate in the plasma with reduced electron temperature. This device comprises at least one levitation electrode for thermophoretic levitation of particles in plasma with reduced electron temperature or an optical forceps device.
EFFECT: enabled efficient growing of high-purity duly shaped particles with monocrystalline diamond structure having sizes from 50 μm to cm range (for instance, 3 cm).
19 cl, 5 dwg
FIELD: processes of chemical infiltration or chemical deposition from vapor phase, case hardening in furnace.
SUBSTANCE: method is used for monitoring process realized in furnace with use of gas reagent containing at least one gaseous hydrocarbon. Method comprises steps of adjusting working parameters of furnace; adding into furnace gas-reagent containing at least one gaseous hydrocarbon; discharging from furnace exhaust gases that contain by-products of gas-reagent reaction; washing out exhaust gases by means of oil that absorbs resins present in exhaust gases; receiving information related to process according to measured quantity of resins absorbed by oil. It is possible to change working parameters of furnace such as temperature, pressure in furnace, gas-reagent consumption and composition.
EFFECT: possibility for monitoring process in furnace without special apparatus of infiltration furnace.
14 cl, 1 dwg, 1 ex
FIELD: the invention refers to application of covers in a liquefying layer particular to an arrangement for settling covers in a liquefying layer.
SUBSTANCE: the arrangement for settling covers in a liquefying layer has a chemical reactor of a cylindrical form and a system of feeding with liquefiable gas, the inner surface of the cylindrical reactor is provided with vertical grooves located on ribs of regular polygons inscribed into the inner diameter of the reactor. At that the number of grooves is chosen in the limits 3-20, the grooves in the section have a form of an equilateral triangle and for a reactor with a diameter of 20-100 mm the relation of squares of transversal sections of the reactor and of all grooves is in the limits 100-200.
EFFECT: the invention provides stability of a liquefying layer at essential increasing of the particles' mass in the process of applying a cover.
1 cl, 1 dwg
FIELD: metal science; protection of materials against external and corrosive attacks.
SUBSTANCE: proposed method for producing diamond-like films designed for encapsulating solar photocells to protect them against chemical, radiation, and mechanical damage includes variation of ion kinetic energy, plasma discharge current, and spatial density distribution of plasma incorporating C+, H+, N+, and Ar+ ions by acting upon ion current from radial source with electric field built up by stop-down, neutralizing, and accelerating electrodes. Spatial plasma distribution is checked for uniformity by measuring plasma current density on solar photocell surface whose temperature is maintained not to exceed 80 oC. In the process substrate holder makes complex axial movement in three directions within vacuum chamber. Diamond-like films produced in the process on solar photocell surface area over 110 cm2 are noted for uniformity, difference in their optical parameters variable within desired range is not over 5%.
EFFECT: enhanced adhesive property, microhardness, and resistance of films to corrosive attacks.
5 cl, 12 dwg, 2 tbl
SUBSTANCE: invention relates to nanotechnology and nanomaterials and can be used at receiving of inorganic and organic-inorganic fine-grained and nano-structured metallised materials, metal-polymers and nanocomposite. Suspension of organic-inorganic nanostructures, containing nanoparticles of noble metals, implemented in the form of poly-complex in two-phase reacting system, consisting of two volume contacting immiscible liquids. Poly-complex includes organic molecules, containing amides in amount 2 or more, and nanoparticles of noble metals. Suspension is received by means of forming of two-phase reacting system, consisting of two contacting volumetric immiscible liquids, addition in it of restorative and synthesis of nanoparticles. Additionally metallised molecules of precursors are dissolved in hydrophobic phase, reducer is added into aqueous phase, and in the capacity of ligands there are used organic molecules, into content of which there are included amides in amount 2 or more. Invention provides receiving of new nano-structured organic-inorganic polymeric complexes on the basis of polyamines, containing nanoparticles of noble metals (Pd, Au) of size up to 10 nm, which allows high specific surface area and are characterised by narrow dispersion of dimensions.
EFFECT: it is provided high density of particles packing in organic-inorganic nano-structures and high performance of transformation of initial material into nanoparticles of noble metals.
23 cl, 12 dwg, 1 ex
SUBSTANCE: invention relates to nanotechnology and can be used for effective change of physicochemical properties of formed on nanoparticles surface inorganic nature of ligand envelope. For receiving of nanoparticles solution with ligand envelope into solution of metal salt in water or organic vehicle is successively introduced stabiliser solution, consisting ligands, and solution of reducer. After it is changed charge sign of ligand envelope by means of one-sided diffusion of substance molecules, changing charge sign of ligand envelope through the semipermeable membrane, into solution of nanoparticles. Additionally it is used membrane, allowing pores size less than size of nanoparticles, but more than size of substance molecules, changing charge sign of ligand envelope. In the capacity of stabiliser it is used substance, molecules' size of which less than size of semipermeable membrane pores.
EFFECT: it is provided receiving of nanoparticles with ligand envelope with specified properties.
2 cl, 2 ex
SUBSTANCE: invention relates to production of nanodisperesed metals in a liquid phase. One provides for passage of alternating current between electrodes immersed in a liquid phase and particles of metal being dispersed introduced into the interelectrode space. Ratio of the electrode length to the width of the spacing between the electrodes is equal to 20÷200:1. The electric current voltage and frequency are maintained at the level of 1.5-5.5 kV and 0.25-0.8 MHz accordingly. Additionally an inert gas is injected into the liquid phase in the form of bubbles sized 0.1-0.5 mm. The liquid phase is agitated due to continuous circulation of the liquid phase, particles of metal being dispersed and the inert gas within a looped circuit including the interelectrode space.
EFFECT: provision for extension of the functional capabilities of the method for production of nanodispersed metals in a liquid phase, its simplification, performance enhancement and improvement of working conditions.
4 cl, 14 dwg, 2 tbl, 9 ex
FIELD: technological processes.
SUBSTANCE: invention is related to the field of metal plastic working and may be used in manufacturing of multiplane pipelines for pneumatic hydraulic systems of aggregates and machines. Module for electropulse and sphere-dynamic power plasticisation of pipeline billet metal comprises device for electropulse processing and device for power processing with sphere-dynamic impact pulses. Device for electropulse processing comprises current collectors connected to generator of electric pulses, and two faceplates. Faceplates are connected by two vertical stands with elastic elements. One of faceplates has the possibility of reciprocal displacement along vertical stands. Device for power processing has two strikers. Working surfaces of strikers are arranged along differently directed curves of logarithmic spiral of Ya.Bernoulli with different lifting angles.
EFFECT: provision of generation of regulated field of compressive stresses in metal purified from dislocations, which guarantees preservation of geometry of pipelines made of billets.
FIELD: technological processes.
SUBSTANCE: invention is related to the field of metal plastic working and may be used in manufacturing of multiplane pipelines for pneumatic hydraulic systems of aggregates and machines. Pipe billet is exposed to initial impact pulses of sphere dynamic action. Pulses are applied to diametrically installed sections of external surface of billet along curve having shape of logarithmic spiral of Ya.Bernoulli. Moreover, deformation extent is provided on every side of billet along its whole length, which is identified from the given expression. Then series of electric current pulses are applied to billet with current density in pulse Q=(1.2…2.0) 104. Duration of electric current pulses action τ=(0.3…0.4) T, where: T is duration of action at pipe billet with initial impact pulses. Then secondary impact pulses of sphere dynamic action are applied on external surface of pipe billet. Value of deformation extent from every side of pipe billet from secondary impact pulses is identified from given expression.
EFFECT: provision of generation of regulated field of compressive stresses in metal purified from dislocations, which guarantees preservation of geometry of pipelines made of billets.
2 dwg, 1 ex
SUBSTANCE: invention relates to methods of applying electroconductive nanostructurised coverings with high electroconductivity and wear-resistance. Method includes supply of powder composition with reinforcing particles from four measuring apparatuses into supersonic stream of heated gas and application of powder composition on product surface. First, from first measuring apparatus reinforcing ultra-dispersive particles of ZrO2 with fraction from 0.1 to 1.0 mcm are supplied and product surface is processed until juvenile surface is formed. Then powder composition based on Cu or Al is applied on product surface by supplying powder from four measuring apparatuses. From the first measuring apparatus reinforcing ultra-dispersive ZrO2 particles are supplied, from the second - Cu or Al powder, form the third - reinforcing nanoparticles of quasi-crystalline compound of system Al-Cu-Fe, and from the fourth measuring apparatus - reinforcing particles Y2O3. Rate of heterophase flow during application of composition based on Cu or Al is changed within the range from 450 to 750 m/sec.
EFFECT: reduction of porosity, increase of wear-resistance, adhesive and cohesive strength of covering preserving its high electroconductivity.
4 cl, 1 tbl, 1 ex
SUBSTANCE: invention is provided for nanoelectronics, analytical chemistry, biology and medicine and can be used for manufacturing of sensors, polymers and liquid crystals. Between volumes of liquid hydrocarbon composition and electrically conducting liquid it is formed boundary, on which there are actuated microplasmous discharges by means of voltage application between electrodes, located in these volumes. Using power supply with frequency 50 Hz, providing smoothly varying of preset voltage from 0 up to 4000 V, it is implemented anodic or cathodic high-voltage polarisation of boundary and high-temperature electrochemical conversion with formation of carbon-bearing nano-materials. In the capacity of liquid hydrocarbon compound can be used, for instance, benzol or octane; in the capacity of electrically conducting liquid - solution of potassium hydroxide, solutions of halogenides of alkaline metals. On boundary it can be located diaphragm, implemented of glass or from aluminium foil with oxide coating.
EFFECT: receiving the ability to implement controllable synthesis of carbon-bearing nano-materials.
8 cl, 6 dwg, 3 tbl
SUBSTANCE: invention relates to method of receiving of powder of nano-crystalline calcium hydroxyapatite. Nano-crystalline calcium hydroxyapatite is received by interaction of calcium hydroxide and solution, containing phosphate-ions, herewith suspension of calcium hydroxide is prepared directly before interaction with solution, containing phosphate-ions from solutions of calcium acetate and potassium hydroxide, herewith amount of calcium hydroxide is from 50 up to 100% in mixture of calcium-bearing components.
EFFECT: receiving of hydroxyapatite powder with particles size 30 - 50 nm.
3 dwg, 1 tbl, 1 ex
SUBSTANCE: invention relates to method of receiving of nano-crystalline hydroxyapatite. According to the invention calcium nano-crystalline hydroxyapatite is received by interaction of compound of calcium and ammonium hydro-phosphate. In the capacity of calcium compound it is used sugar lime C12H22-2nO11Can, at n, which is situated in the range from 0.5 up to 2. Particles size of the received hydroxyapatite is 30-50 nm.
EFFECT: receiving of nano-crystalline powder of calcium hydroxyapatite, which contains unaggressive biocompatible accompaniment of the reaction and that provides its usage in medicine.
3 dwg, 1 tbl, 1 ex
SUBSTANCE: invention relates to micro system hardware, and can be used in producing sensors based on tunnel effect to convert displacement into electric signal in monitoring data processing systems that serve to forecast, diagnose and control the effects of impact waves and acoustic oscillations exerted onto various structures, vehicles, industrial buildings and structures, as well as to control temperature, develop supersensitive mikes and medicine hardware. In compliance with this invention, the sensor cantilever electrode represents a bimorph beam made up of consecutively formed layers differing in thermal expansion factors. Note that the lower layer thermal expansion factor is lower as compared with that of the upper layer. Note also that the tunnel electrode represents a bundle of nanotubes. The proposed nanosensor incorporates thin-film heater to allow desorption of low-molecular substances, precision alignment of tunnel gap and formation of nanotubes after removal of "sacrificial" service layer.
EFFECT: increased sensitivity, vibro- and impact resistance, manufacturability and reproducibility, lower costs of manufacture.
2 cl, 3 dwg
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.