Method of production of carbon nanofibres and/or carbon nanotubes

FIELD: nanotechnology.

SUBSTANCE: invention relates to a method of production of carbon nanofibres and/or carbon nanotubes. The method comprises the pyrolysis of dispersed cellulosic and/or carbohydrate substrate impregnated with a compound of the element or elements, which metal or alloy, respectively, is able to form carbides in the substantially oxygen-free atmosphere comprising a volatile silicon compound, optionally in the presence of carbon compound.

EFFECT: invention enables to obtain carbon nanotubes or nanofibres of a certain shape.

15 cl, 4 dwg


Carbon nanofibers (UNV), carbon nanotubes (CNTS) and composites, including (hereinafter herein jointly referred to as UNV), in the last few years given the increasing attention due to their high strength, chemical purity and chemical inertness, as these characteristics make them ideal for use as a catalyst carrier.

Promising is the use of materials UNV as a carrier in various catalytic methods, such as the Fischer-Tropsch synthesis and selective hydrogenation. Catalytic performance catalysts deposited on carbon media (graphite, charcoal), can be adjusted as a result of changing media properties, like the number of oxygen-containing surface groups, the availability of the media and the degree of orderliness of carbon. A similar effect of the media on the characteristics of the catalyst takes place in the case of the catalyst metal/UNV.

To obtain good material catalyst carrier must meet several important conditions, such as high bulk density, high strength and high porosity. The high density of carriers lead to a more efficient use of reactor volume and so are the two who are economically attractive in comparison with native low density. On the other hand, in order to avoid limitations on mass transfer, critical porosity media (availability).

Properties UNV potentially superior properties of the usual oxide carriers, like, inter alia, silicon dioxide and aluminum oxide. Carbon nanofibers are chemically inert, clean and durable mechanical and, thus, are suitable for use as the material of the catalytic carrier. UNV consist of intertwined individual carbon nanofibers, which are formed during the catalytic cultivation in the decomposition of carbon-containing gases, such as CO/H2, OH4C2H4or other volatile compounds, such as toluene and the like, catalysts based on metals such as catalysts that are based on Nickel, cobalt, iron, ruthenium, and combinations and/or alloys, and the like. Suitable carrier materials are silicon dioxide, aluminum oxide, magnesium oxide, carbon, carbon fiber, and the like.

The two most frequent forms of UNV represent the type of "fish bone" and the parallel type (also called multi-walled carbon nanotubes). The fibers of type "fish bone" plane of graphite is oriented at an angle to the Central axis, thus, Najaat edge planes of graphite. If the orientation of the planes of graphite parallel to the Central axis, as in a parallel type UNV, naked will only basal plane of graphite.

It was proposed to obtain such carriers of catalysts from carbon nanofibers or nanotubes. In the publication WO 93/24214 the use of carbon nanofibers or nanotubes as carriers of catalysts, in which the graphite layers are oriented essentially parallel to the axis of the elementary fibers. However, it is difficult to control the dimensions of such relatively long and straight elemental carbon fibers. Indeed, for a catalyst size and porosity are important. In a stationary catalyst structure sizes media determine the pressure drop and transfer of reagents and reaction products through the structure of the catalyst. In the case of catalyst suspended in the liquid, the transfer of the reactants and reaction products is of great importance. The dimensions of the structures of the catalysts, as mentioned above, are of great importance for migration and to separate structures, for example, filtration or centrifugation.

Another disadvantage is the need of growing carbon nanofibers or nanotubes on the metal particles deposited on carriers such as silica or XID aluminum. These media often create difficulties for the application of the carbon carriers in liquid-phase reactions. The removal of silicon dioxide or aluminum oxide in the treatment with alkali or acid, respectively, is difficult.

In the publication WO 2005/103348 suggested obtaining materials UNV very high density, having a bulk density of at least 800 kg/m3. This is done in the growing carbon nanofibers on the surface of metal catalyst supported on a carrier and producing carbon fiber, such as Nickel, cobalt, iron and ruthenium catalyst by decomposition of hydrocarbons over a period of time sufficient to obtain the desired bulk density, optionally with subsequent removal of the catalyst of growth.

These materials UNV so far not enjoyed great success, mainly because it is very difficult to obtain a molded body, which is characterized by sufficient strength for use as a material carrier of a catalyst or as a catalyst.

In accordance with this first objective of the invention is to offer material UNV/CNTS, which can be suitably processed into a form suitable for use in catalysis. One is an additional objective is to obtain these materials from a relatively common natural materials, in some circumstances, even without having to resort to the use of an external supply of carbon compounds (often from non-renewable sources).

In accordance with this present invention relates to a method of producing carbon nanofibers and/or carbon nanotubes, where the method comprises the pyrolysis of dispersed cellulose and/or carbohydrate substrate, which was impregnable connection element or elements, the metal or alloy which, respectively, capable of forming carbides, essentially free from oxygen atmosphere containing volatile compound of silicon, optionally in the presence of carbon compounds.

Unexpectedly, it was found that when using this method are very interesting and appropriate form of materials UNV, as you can see from the obtained by electron microscopy photographs referred to in the example.

The method involves impregnation of the substrate metal connection or combination of compounds of metals with subsequent pyrolysis of the impregnated substrate. Metal compounds preferably are salts of these compounds of metals, more specifically, in aqueous solution. Elements (metals) have the property, i.e. the formation of these carbides. Examples of suitable element is in are Nickel, cobalt, iron and molybdenum. Preferred are iron and Nickel.

Also unexpectedly, it was found that of alternative materials containing cellulose and/or carbohydrates, such as soybean meal, sugar, hydroxyethylcellulose, cellulose and its derivatives, and the like, can be obtained spheres, which, after thermal decomposition also produce a mechanically stable carbon spheres. With regard to much greater cheapness of soybean meal compared with a very pure microcrystalline cellulose is a significant advantage. Data carbon spheres form the core material UNV, who, in the course of implementation of the method grows on the surface of the spheres.

Another source material, suitable for the production of carbon spheres, is a sugar or mixture of sugars and microcrystalline cellulose or soybean meal. In accordance with the preferred technique uses carbon structure obtained as a result of hydrothermal processing of materials derived from agriculture, such as sugar, starch, soybean meal, (Hemi)cellulose and digidrirovannye products of the above compounds, such as furfural and 2-hydroxyphenyl. Preferably the dehydration of the above-mentioned compounds is carried out in accordance with the description in publicat is In Neither, Shu-Hong Yu, Kan Wang, Lei Liu and Xue-Wei Xu, Dalton Trans. 2008, 5414-5423 and in the references mentioned in this document. After impregnation of structures subjected to hydrothermal treatment, conduct heat treatment corresponding to the method of the present invention. Alternatively, a solution of metal compounds may also be mixed in water, used during the hydrothermal processing. During thermal decomposition of areas that are predominantly or exclusively contain sugar, it is necessary to pay attention to the fact that during heating the temperature at which the sugar is melted, would pass so quickly, the sugar is decomposed, even how to develop the melting process. As it was found, is also effective and dehydration of sugar before the temperature rises to the temperature of decomposition. Given the low cost of sugar and other materials containing cellulose, the present invention is of great importance for industrial applications mechanical solid carbon particles.

In the General case of cellulose or carbohydrate source materials will contain organic materials, usually from renewable sources, which have the property that when they pyrolysis in inert conditions forms a gas having reducing properties.

So, how unexpected the Anno was established, carbon nanofibres and/or nanotubes can be grown by heating the spheres containing cellulose and/or carbohydrate and impregnated compound of iron and/or Nickel, in the presence of a volatile silicon-containing compounds, preferably in the absence of gas, which is the external source of carbon atoms, in an inert stationary atmosphere. Gases released during the pyrolysis of cellulose, can be a carbon source to grow carbon nanotubes.

Because UNV consist of carbon for the synthesis of these materials requires a carbon-containing gas. In one preferred embodiment, the gas generated in the pyrolysis of carbon spheres, but in one alternative embodiment, additional gas may be fed from an external source.

Additional carbon-containing gas upon receipt of the UNV may be any suitable carbon-containing gas, such as usually used in the prior art. Examples are CO, a mixture of CO/H2CH4With2H4and other gases, such as lower alkanes, alcohols, alkylene, alkynes, aromatic compounds such as benzene and toluene, and the like. Preferred is the use of methane, toluene or CO/H2. Instead of the highly toxic CO can be used methanol. Optional ha which may be diluted with an inert gas, such as nitrogen.

Pyrolysis takes place in a reactor suitable for receiving UNV, such as a reactor with a fluidized bed reactor fixed bed, lift / Elevator-lift reactor. The temperature in the reactor is kept on a level that is appropriate for pyrolysis and receiving fibers. The temperature depends on the nature of the catalyst and the nature of the carbon-containing gas. General the lower limit temperature is 400°C. For gases such as methane and CO/H2temperature in General ranges from 400°C to 925°C. the Total upper limit for the temperature is 1250°C.

After receiving composites UNV they can be used as such for various applications such as an additive to the polymer, hydrogen storage, microelectronics, fixing homogeneous catalysts or enzymes, more specifically, as a catalyst carrier. Because no individual supported on a carrier, the catalyst is not used, there is no need to remove the carrier (usually an oxide) in contrast to methods of the prior art. In accordance with the present invention, the material of the carrier compounds of iron or Nickel is also subjected to pyrolysis and conversion to carbon.

After receiving UNV them additionally, you can modify, for example, for even more material removal and/ilids the introduction of oxygen-containing groups on the surface of the UNV in order to obtain oxidized UNV. Data processing generally include the use of HCl and/or H2SO4/HNO3(with variable ratios) or the oxidation of gaseous oxidizing agents in accordance with the prior art.

The invention also relates to the use of materials UNV as a catalyst or catalyst carrier. Composites can be used as such for the reactions that kataliziruetsa carbon, optionally after the surface modification as a result of oxidation. However, preferably on the surface of the UNV put suitable catalytically active material. Suitable catalytically active material may be a metal-based or metal oxide, such as Nickel, copper, tungsten, iron, manganese, zinc, vanadium, chromium, molybdenum, rhodium, iridium, ruthenium and the like, and combinations thereof. You can also use the UNV and as a carrier for catalysts based on precious metals, such as those that are based on platinum, palladium, gold or silver, and combinations thereof. It is also possible on the surface of UNV to fix and ORGANOMETALLIC or metalloplastikovye catalysts.

Upon receipt of the catalyst having UNV as a carrier, preferably using oxidized UNV, because it improves the dispersion of the act the main catalyst precursor by UNV and thus, increasing the stability of the final catalyst, more specifically, the Nickel catalyst, in relation to sintering.

The catalytic material can be deposited on UNV in the usual way, such as impregnation or homogeneous adsorption from solution. For metals is preferred to use a homogeneous adsorption from solution, such as described in the publication "Synthesis of highly loaded highly dispersed nickel on carbon nanofibers by homogeneous deposition-precipitation", Bitter, J. H., M. K. van der Lee, A. G. T. Slotboom, A. J. van Dillen and Jong, Cat. Lett. 89 (2003) 139-142.

Suitable reaction both in liquid and in the gas phase, which can be used catalysts supported on a carrier UNV represent the Fischer-Tropsch synthesis, hydrogenation reactions, reactions of dehydrogenation, hydrobromide, such as hydrodesulphurization unit, reaction mahanirvana, the reaction of low-temperature oxidation and the like.

Example 1

Sphere microcrystalline cellulose (MCC) was soaked with a solution of ammonium citrate iron in the water. After this MCC spheres were dried in vacuum. The impregnated spheres MCC inflicted on iron grid with a layer of adhesive on the basis of silicone rubber. For this purpose, iron mesh was coated from dilute solution of silicone rubber. Before hardening silicone rubber impregnated spheres MCC stuck to a layer of glue on the again of silicone rubber. After that, the grid comprising the impregnated spheres were injected into an inert stationary nitrogen atmosphere and was heated up to 800°C. This led to the growth of a dense layer of short straight carbon nanotubes on the surface of carbon spheres. In Fig.1 shows obtained by electron microscopy photograph of the resulting material. Fig.2 provides an enlarged image of Fig.1.

Example 2 (comparative)

The MCC spheres were impregnated with a solution of Nickel nitrate in water. After this MCC spheres were dried in vacuum. Spheres impregnated with Nickel, was heated up to 800°C in an inert (flow) under nitrogen atmosphere in the fluidized bed. Subjected to pyrolysis carbon sector, including small particles of elemental Nickel, cooled to 500°C. the gas composition was changed to 90% (vol.) N2and 10% (vol.) H2. Within two hours using saturator they dosaged toluene. As a result, this led to the growth of the carbon nanofibers having the structure type "fish bone", on the surface of carbon spheres. The figure 3 shows the obtained by the method of electron microscopy photograph of the resulting material. Figure 4 gives an enlarged image of figure 3.

1. Method of producing carbon nanofibers and/or carbon nanotubes, which includes pyrolysis dispersion is aqueous pulp and/or carbohydrate substrate, impregnated connection element or elements, the metal or alloy which, respectively, capable of forming carbides, essentially free from oxygen atmosphere containing volatile compound of silicon, optionally in the presence of carbon compounds.

2. The method according to p. 1, where the said substrate is selected from microcrystalline cellulose, sugar or mixture of sugars and microcrystalline cellulose or soybean meal.

3. The method according to p. 1 or 2, where the substrate includes carbon structure obtained as a result of hydrothermal processing of materials derived from agriculture, such as sugar, starch, soybean meal, (Hemi)cellulose and digidrirovannye products of the above compounds, such as furfural and 2-hydroxyphenyl.

4. The method according to PP.1-2, where the substrate impregnorium compound of Nickel, cobalt, iron and/or molybdenum, preferably in an aqueous solution of salts of Nickel and/or iron, with subsequent drying and pyrolysis.

5. The method according to PP.1-2, where the above-mentioned substrate is subjected to pyrolysis in the presence of silicone rubber.

6. The method according to PP.1-2, where the above-mentioned silicon compound is alkyloxy, preferably gaseous trimer of siloxane.

7. The method according to p. 6 where the above-mentioned siloxane compound is a trim is R dimetilsiloksana.

8. The method according to PP.1-2 or 7, where the pyrolysis is carried out at a temperature in the range from 500 to 1000°C, preferably for a period of time ranging from 5 minutes to 5 hours.

9. The method according to PP.1-2 or 7, where the atmosphere is essentially free of carbon compounds.

10. The method according to PP.1-2 or 7, where the atmosphere further comprises at least one carbon compound such as a compound selected from toluene, CO, mixtures of CO/H2CH4With2H4and other gases, such as lower alkanes, alkylene, alcohols, alkynes, aromatic compounds such as benzene and toluene, and the like.

11. Carbon particles formed by carbon nanotubes and/or nanofibers obtained by the method according to any one of paragraphs.1-10.

12. The catalyst or catalyst precursor comprising a carrier and at least one catalytically active material or its predecessor, with the above-mentioned material of the carrier is a carbon particles formed by carbon nanotubes and/or nanofibers under item 11.

13. The catalyst according to p. 12, these catalytically active material selected from the group of noble metals, rhodium, Nickel, iron, copper or combinations thereof.

14. The method of conducting at least one chemical reaction in the presence of a catalyst deposited on n the Khabibullina, where the above-mentioned catalyst supported on a carrier, includes a catalyst according to any one of paragraphs.12 or 13.

15. The method according to p. 14, where a chemical reaction selected from the group reactions of Fischer-Tropsch, hydrogenation reactions, dehydrogenation reactions, reactions mahanirvana, low-temperature oxidation reactions.


Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to chemical technology, in particular to processes of carbonisation of fibrous viscose materials, and can be used in production of graphitised fibrous materials, used as filling agents of composite materials; electrodes; flexible electric heaters; filters of aggressive media; in products for sport and medical purposes, etc. The material is preliminarily subjected to relaxation processing. The obtained material, which contains a pyrolysis catalyst, is continuously transported through zones of carbonisation heating. Carbonisation is carried out to 320-360°C in not less than three zones of heating, heat- and gas-isolated one from another by transporting material with inclination from bottom to top, with increase of heating temperature from 160-200°C in the first zone by 40-60°C in each next zone of heating, in comparison with the previous one. Volatile products are simultaneously removed from the said zones into the evacuation zone, heat- and gas-isolated from the external environment and located above the heating zones and connected with them via a perforated wall. Temperature in the evacuation zone of volatile substances is set by 5-15°C higher than temperatures of the respective heating zones, temperature of the output branch piece being 5-15°C above the maximum temperature of carbonisation.

EFFECT: invention ensures increase of the process efficiency and improvement of quality of the obtained carbon fibrous materials.

2 dwg, 1 tbl, 5 ex

FIELD: textiles, paper.

SUBSTANCE: invention relates to chemical technology of fibrous materials and relates to installation of carbonisation of fibre viscose materials for obtaining composite carbon filaments. The installation comprises a housing and a carbonation chamber placed in it, which end walls are provided with slotted holes for input of the source material and output of carbonised material, and sealing closures, as well as electric heating elements, pipe branches for supply of inert gas and output of distilling gases. The housing with the chamber is mounted obliquely at an angle 10-15° to the horizontal plane. The hole for input of the source material is located in the lower end. The chamber is placed into the additional casing, which upper wall is spaced from the upper chamber wall at a distance of 100-150 mm, is provided with a transverse slot that extends the entire width of the upper wall of the chamber and communicates with the pyramidal-shape pipe branch for devolatilisation, integrally mounted near the output end of the housing of the installation, and equipped with heating. Heat insulation of the installation is located between the walls of the housing and the casing, the heaters are located outside the chamber, at that they are in direct contact with the lower wall, and in relation to the upper wall they are fastened with the possible variable clearance.

EFFECT: invention provides improvement of the installation design and improves the quality of the carbonised material produced at this installation.

5 cl, 3 dwg

FIELD: chemistry.

SUBSTANCE: method involves treating viscose fibre material with pyrolysis catalysts, heating to carbonisation temperature and subsequent graphitation to temperature of 3000°C in an inert medium. Carbonisation is preceded by preparation of precursor by preliminary washing of the starting material with water and/or 5-10% sodium hyposulphite solution with heating and drying, and/or ionising irradiation with a beam of fast electrons during transportation through the irradiation chamber of an electron accelerator, and/or warm-wet synthesis of a complex catalyst on the surface of viscose fibres and in the pore system thereof in boiling 10-20% aqueous ammonium chloride solution and with addition of diammonium phosphate in ratio of 0.5-4.0, followed by steaming in hot steam and final ventilated drying with constant transportation, which enables to deposit the catalyst in form of an amorphous film.

EFFECT: high stability of the process of carbonising viscose fibre material and improved physical and mechanical properties of the obtained carbon material.

6 cl, 7 dwg, 1 tbl, 12 ex

FIELD: textiles, paper.

SUBSTANCE: method of producing carbon fiber material comprises treatment of the starting hydrocellulose fiber material in a solution containing 5-7 wt % liquid oligomeric resins corresponding to the general formula: HO{[MeSi(OH)O][Me2SiO]m}nH, where Me is methyl; m and n are integer or fractional numbers: m=1-3, n=3-10 with a molecular weight from 900 to 2400. As the solvent of the oligomeric resins, a composition is used based on compounds of general formula: (SiO)xCyHz, where 3≤x≤5, y=2x, z=3y. The impregnated hydrocellulose material is dried at a temperature of (150-170)°C, thermally relaxed in the mode of relaxation shrinkage at a temperature of (180-200)°C, the carbonisation is carried out during deformation from (-25)% to (+30)% and finished at a temperature of 700°C, the subsequent high-temperature treatment is carried out at a temperature up to 2500°C at a degree of deformation of (-10)% to (+30)%.

EFFECT: improvement of physical and mechanical properties of carbon fiber material in creation of an environmentally safe technological process.

5 ex

FIELD: chemistry.

SUBSTANCE: method involves soaking starting cellulose fibre with an aqueous solution containing 6.5% dibasic ammonium phosphate, 10.6% ammonium chloride and 2.5% sodium chloride at 30°C for 30 minutes, followed by pressing. The fibre is then dried at 95±5°C using a microwave source and then heat treated in a medium of methane to 220°C. The partially carbonised material is heated in a medium of nitrogen to 2400°C. The microwave source has output power of 1-50 kW and operating frequency of 100-300 MHz.

EFFECT: invention increases efficiency of the method of producing carbon fibre with high strength.

2 ex

FIELD: process engineering.

SUBSTANCE: proposed method comprises processing initial cellulose fibrous material by liquid-phase composition containing silanol groups with molecular weight varying from 900 to 2400 and viscosity varying from 520 to 1700 cPs, and 2-7%-water solution of fire retardant. Processed material is dried to 105-125°C for 60-120 min. Then, carbonisation is performed in air at 140-170°C for 25-40 min. Carbonisation is terminated at 700°C to proceed with high-temperature processing at, at least, 2200°C.

EFFECT: high physical properties and yield.

4 cl, 6 ex

FIELD: metallurgy.

SUBSTANCE: invention can be used as fillers of composite materials of structure, heat protecting, anti-electro-static purpose and also at production of carbon fibrous adsorbents, catalyst carriers, materials for protection from electro-magnetic radiation, nano structured composite, fullerenes, nano tubes etc. The procedure consists in impregnation of a source unidirectional braid with solution of fire retardant. Braid is made of hydrated cellulose fibres with fine crystal non-tensioned structure with diametre of filament from 8.5 to 15 mcm at its linear density 0.07-0.17 tex. Further, the procedure consists in drying, non-oxidation stabilising carbonisation and graphitisation. As a fire retardant there is used water solution containing 150-200 g/l of ammonia chloride and 10-30 g/l of urea or water solution containing 250-300 g/l of ammonia sulphate and 20-40 g/l of urea. Drying is carried out by electric heating at 120-140°C during 30-60 min. Before carbonisation braid is treated in oxygen containing atmosphere at 140-180°C during 30-90 min. Multi-zone carbonisation is performed in current of inert medium at rate 2.5-4.5 m3/hour during 40-80 min for 5-10 min in each zone with shrinkage of source hydrated cellulose fibre at 10-30 % and at temperature from 170-230°C to 690-710°C. During carbonisation products of pyrolysis in a zone of their highest release are withdrawn due to a low excessive pressure of neutral gas of 120-150 mm of water column at continuous oxidation in spots of combustion. Graphitisation is carried out at 1000-2400°C in medium of nitrogen or argon with contents of oxygen not over 0.001% at rate of drawing 15-50 m/hour.

EFFECT: reduced duration of process, considerable reduction of humidity of produced carbon fibre, multi-zone carbonisation with guaranteed maintenance of uniform temperature of each zone, reduced release of amorphous carbon as product of resin decomposition and prevention of its settling on surface of produced carbon fibre.

7 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: in continuous mode, the method involves saturation of initial fibres at the pre-carbonisation step with an aqueous emulsion containing an oligomeric resin, drying, thermal relaxation and carbonisation and, if needed, graphitation. Saturation is carried out in the aqueous emulsion of the oligomeric resin with high content of silane groups of general formula HO{[MeSi(OH)O][Me2SiO]m}nH, where: Me is metal; m and n are integers or fractional numbers: m=1-3, n=3-10, with molecular weight of 900-2400 and viscosity of 520-1700 cP, in a spinning-finishing assembly when producing viscose industrial threads. Before saturation, the fibres are dried at 120-180°C for 10-15 s. Thermal relaxation is carried out at 160-200°C for 0.5-2.0 h and carbonisation is completed at temperature 600°C. Different textile structures, for example a net, fabric, knitted fabric or nonwoven material from the initial cellulose fibre materials is saturated.

EFFECT: invention enables to obtain carbon fibre materials with good physical and mechanical characteristics while reducing the coefficient of variation in strength characteristics.

4 cl, 8 ex

FIELD: chemistry.

SUBSTANCE: stabilisation method involves putting carbonaceous fibre into a gaseous medium, its treatment with microwave radiation while simultaneously heating the gaseous medium. In a special case, the fibre is put into a working chamber containing a gaseous medium, heating the gaseous medium by heating the chamber (its walls) while simultaneously treating the fibre with microwave radiation. The method of producing carbon fibre involves at least a stabilisation step and carbonising the fibre. Precursor stabilisation is carried out using the method described above. The fibre can undergo further graphitation after carbonisation. Complex treatment with microwave radiation can be carried out while simultaneously heating the medium in which the fibre is put in order to carry out carbonisation/graphitation.

EFFECT: shorter time for stabilising precursor fibre, which results in low power consumption and high efficiency of the process of producing carbon fibre.

11 cl

FIELD: machine building.

SUBSTANCE: procedure consists in cellulose thread spinning from solution of viscose or solution of cellulose, in washing cellulose threads in water, in impregnation of washed and not-dried cellulose fibres with water emulsion of at least one silicon-organic auxiliary substance, in drying impregnated fibres of cellulose, in production of fibrous structure composed of impregnated and dried fibres of cellulose and in carbonisation of fibrous structure.

EFFECT: produced structures possess high mechanic indices.

14 cl, 5 dwg, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to modification of the surface of inorganic fibre by forming a highly developed surface of inorganic fibre used as filler by forming carbon nanostructures on the surface of the fibres and can be used in producing high-strength and wear-resistant fibre composite materials. The method of modifying the surface of inorganic fibre involves the following steps: (a) soaking inorganic fibre with a solution of an α2 sinter fraction in organic solvents; (b) drying the soaked fibre; (c) heat treatment of the soaked inorganic fibre at 300-600°C; (d) depositing a transition metal salt onto the surface of the fibre heat treated according to step (c); (e) reducing the transition metal salt to obtain transition metal nanoparticles; (f) depositing carbon onto the transition metal nanoparticles to obtain carbon nanostructures on the surface of the fibre. The composite material contains modified fibre made using the method given above and a matrix of polymer or carbon.

EFFECT: high strength of the composite material in the cross direction relative the reinforcement plane by preventing surface deterioration when modifying with carbon nanostructures.

9 cl, 3 ex, 1 tbl, 5 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to heterogeneous catalysis and can be used to recycle hydrocarbons and halogen-substituted hydrocarbons when producing composite materials, catalysts, sorbents and filters. Catalytic pyrolysis of hydrocarbons is carried out at 500-700°C on a catalyst obtained by dispersing articles of solid nickel and alloys thereof with other metals, e.g., iron, chromium, as a result of reaction with 1,2-dichloroethane vapour. The catalyst contains dispersed active nickel particles attached to carbon nanofibres with diameter 0.1-0.4 mcm. The starting material used is bromine- or chlorine-containing hydrocarbons, alkanes, olefins, alkynes or aromatic hydrocarbons, e.g., ethane, propane, acetylene, benzene. Output of carbon nanofibres is equal to or more than 600 g per 1 g metal.

EFFECT: high efficiency of the method.

5 cl, 2 dwg, 9 ex

FIELD: chemistry.

SUBSTANCE: dust-like or granular solid substance is continuously sprayed onto the outer surface of a hollow drum substrate 2. After deposition, the catalyst on the revolving substrate enters reaction zone 3, into which carbon-containing gas is continuously fed through a gas-distributing collector 17, and gaseous pyrolysis products are continuously output through a nozzle 18. The reaction zone is heated with infrared heaters 7. The end product is removed from the substrate using a blade 9 and a cylinder brush 10, and then unloaded from the apparatus by an auger 14.

EFFECT: invention enables continuous synthesis of carbon fibre materials.

5 cl, 2 dwg, 2 ex

FIELD: electricity.

SUBSTANCE: invention can be used for creation of fillers of composite materials, gas-distributing layers in fuel elements, components of lubricants, hydrogen storage batteries, filter materials, carbon electrodes of lithium batteries, glue composites, carriers of catalysts, adsorbents, anti-oxidants during production of cosmetics, cold emission sources of electrons, modifying agents to special-purpose concrete, as well as for coatings screening microwave and RF radiation. Method involves pyrolysis of gaseous carbon-containing compounds on surface of metallised dust catalyst in flow reactor having the possibility of gas medium mixing. Aerosil particles containing clusters of the following metals on the surface as catalyst: nickel, cobalt or iron. Catalysts are obtained prior to the beginning of pyrolysis by reactivation of catalyst sprayed in reactor in current of hydrogen-containing gas at simultaneous mixing of gaseous medium. It is expedient to mix gaseous medium in reactor in fluidised bed mode with ultrasonic material dispersion. Outer diameter of obtained nanotubes is 5 to 35 nm; inner diameter is 4 to 12 nm; packed density is 0.3-0.4 g/cm3; total content of impurities is less than 1.2-1.5%; length is 0.5 to 3 mcm.

EFFECT: invention allows synthesising thinner nanotubes with high cleanliness, which have smaller spread in values as to diameters.

2 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: sprayed catalyst is deposited on the top surface of a rotating disc through the settling chamber of a reactor, heated to pyrolysis temperature, after which hydrocarbon gas is continuously supplied and gaseous pyrolysis products are removed, and at the end of the pyrolysis process, the end product is cooled together with the catalyst. When feeding into the settling chamber, the catalyst is stirred and aerated with an inert gas. The hydrocarbon gas is fed through a gas-distributing apparatus. Gas is released through an annular slit between the disc and the cowling of the gas-distributing apparatus. Gaseous pyrolysis products are removed through socket pieces in the top part of the housing. At the end of the pyrolysis process, heaters are switched off and the housing is cooled to a safe temperature, after which the disc rotary drive is switched on and the material treated with an agitator is moved by a scraper through a window in the bottom part of the housing and removed from the reactor through an auger-type storage bin, whose drive is simultaneously switched on with that of the disc. The apparatus for producing nano-structured carbon fibres has a housing fitted with heaters, in the top part of which there is a pipe for feeding hydrocarbon gas and a unit for feeding the catalyst, connected to the gas-distributing apparatus in form of an inverted funnel with a built-in settling chamber and a socket piece for outlet of pyrolysis products, and in the bottom part there is a window for unloading the ready product, above which there is a disc which is connected to a rotary drive and interacts with a fixed scraper. The gas-distributing apparatus is fitted with a cowling over the disc, on which an agitator which is kinematically linked to the disc is mounted, where agitator is mounted on the path of the disc in front of the scraper for unloading the end product through the window, which joins the auger-type storage bin fitted with an agitator. The batching unit is in form of a screw doser having a mixing device and an aerator-bridge breaking cone.

EFFECT: obtaining nano-structured carbon fibres with high output of the product and high quality.

10 cl, 2 ex, 11 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing fibrous carbon materials through pyrolysis of aromatic and non-aromatic hydrocarbons. A catalyst 9 is deposited on the top surface of a container 8. After sealing the reactor, inert gas is blown inside and heating elements 5 and the disc 6 rotary actuator 7 are switched on. Carbon-bearing gas is fed into the cavity between the cap 10 and the container 8 and the catalyst 9 is heated. Heating is then stopped and a forced cooling system is switched on. After lowering temperature in the reactor, the disc 6 rotary actuator 7 is switched off, the reactor is opened and the container 8 with nanotubes is removed.

EFFECT: invention enables to obtain multilayer carbon nanotubes with diametre of 15-50 nm.

3 cl, 8 dwg, 2 ex

FIELD: machine building.

SUBSTANCE: upon preliminary high temperature treatment catalyst of carbon nano-fibres growth is placed into reactor; reaction zone is heated to temperature of pyrolysis of carbon containing steam-gas mixture supplied into reactor. The mixture includes activators on base of sulphur containing or oxygen containing compounds. Further the mixture is conditioned at temperature of pyrolysis of the above said braids and the reactor is cooled. Linear rate of carbon containing steam-gas mixture supply is within interval from 20 to 300 mm/s.

EFFECT: production of long oriented braids of carbon nano-fibres with multi-layer structure.

9 cl, 5 dwg, 2 tbl, 22 ex

FIELD: production processes.

SUBSTANCE: method involves drawing of carbon fibre through solution with further heat treatment in flow-through gas medium. As solution there used is either solution containing pre-synthesised thin multi-layered carbon nanotubes functionalised with hydroxylic and carboxylic groups in dimethyl formamide or in dimethyl acetamide or in dimethyl sulfoxide with concentration of 0.1-10 g/l, or catalytic solution containing medium for forming embryos for growing nanotubes at heat treatment, and as catalytic solution there used is water solution Co(NO3)2 with concentration of 0.25 mol/l. As gas medium there used is medium containing gaseous hydrocarbon - methane, and heat treatment is performed by keeping it in reactor at temperature of 800-1000°C during 10-30 minutes.

EFFECT: increasing resistance to fibres being drawn from binding material.

4 cl, 5 ex, 6 dwg

FIELD: chemistry.

SUBSTANCE: external diametre of carbon fibres is 15-100 nm. The fibrous structure includes a knot whereto said carbon fibres are connected so that the specified carbon fibres come out from the knot made from growing carbon fibres with size 1.3 times exceeding external diametre of carbon fibres. Once added to hard materials, such as resin, ceramics, metal, carbon fibrous structures taken even in small amount improve physical properties of materials, including electric, mechanical, or thermal properties, not mentioning other material properties.

EFFECT: improved thermal properties.

3 cl, 10 dwg, 4 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention relates to technology of carbonic fibrous materials by catalystic pyrolysis. Receiving method is in reactor location into catalyst in the form of powdered alloy on the basis of aluminium and it is fed carbureted hydrogen gas. Gas feeding and withdrawal of pyrolysis light-end product is going on continuously. Carbureted hydrogen gas is preliminary heated in reactor till the temperature which is lower the pyrolysis beginning. Catalyst on nonmetallic bottom layer is heated higher the temperature of pyrolysis beginning by inductive method with alternating voltage with frequency 20 kHz. Finished product with catalyst is cooled.

EFFECT: receiving of nanoproduct without formation of freak carbon-base material on heated non-catalytic surfaces.

4 cl, 2 dwg, 2 ex

FIELD: electricity.

SUBSTANCE: method for manufacturing of nanosized powders for Li4Ti5O12/C lithium titanate-based compound includes mixing of titanium dioxide, lithium carbonate and starch and thermal treatment of the obtained mix until material is received with 100% spinel structure. Lithium carbonate is taken in 10÷15 wt % excess from stoichiometrically-defined quantity required for receipt of Li4Ti5O12 compound. Starch is introduced in quantity of 10÷20 wt % of the mixture weight. The mixture is treated thermally at temperature of 850°C during 10-15 hours.

EFFECT: invention allows reduced duration of nanopowder synthetic process with receipt of material having grain size of 60-70 nm and high values of discharge capacity.

1 tbl, 1 ex