Method of producing galvanic composite coating containing nanodiamond powder
SUBSTANCE: method involves preparation of a suspension of nanodiamond powder and a liquid phase, adding the suspension to an electrolyte and conducting electrolysis to deposit a composite coating. The liquid phase used to prepare the suspension is ethyl alcohol or acetone, wherein the nanodiamond powder is added to the liquid phase in amount of 60-80 vol. %, and the powder in the suspension is dispersed by crushing and attrition grinding with a lap, after which the suspension is added to the electrolyte.
EFFECT: dispersing nanodiamond powder and endowing the powder with resistance to sedimentation and coagulation in the electrolyte.
The invention relates to the production of galvanic composite coatings, in particular on the basis of Nickel dispersed phase in the form of nano-diamond powders.
The method can be used for the manufacture of diamond tools in which the cutting of the diamond grains are held on the tool body by means of the galvanic composite coatings based on Nickel containing nanodiamond powders. Also the method can be used for deposition of composite coatings to improve hardness, wear resistance of machine parts, instruments, cutting tools, etc.
Galvanic composite coatings are metallic matrix containing a dispersed phase, in particular nano-diamond powders deposited on the surface of an electrolyte containing a salt of the deposited metal and nano-diamond powders. The coating quality is largely determined by the state of the dispersed phase, its concentration and distribution in surface and coating thickness. The concentration and distribution of the particles in the coating to a greater extent depends on sedimentation and coagulation stability of the dispersed phase in the electrolyte, the concentration of particles in the electroplating bath.
A method of obtaining composite coatings comprising introducing into the electrolyte diamond particles RA is the mayor of 1-1000 nm, suspending electrolyte gas, containing oxygen (JP No. 2006225730, CL C25D 15/02, 2006). The result is an electrolyte with evenly distributed over the volume of the diamond particles. The disadvantage of this method is that the suspending of the diamond particles in the electrolyte gas is not attached to the particle sedimentation and coagulation of sustainability, as it does not guarantees the complete destruction of the conglomerates of particles, which does not allow to obtain high-quality coverage.
A method of obtaining composite coatings of electrolytes, including the introduction of electrolyte dispersed phase of nanodiamonds and dispersion effects on the electrolyte cavitation, passing it through cavitation disperser, or the use of hydrodynamic or acoustic dispersant (RU # 2368709, CL C25D 15/00, 2007). The disadvantage of this method lies in the use of complex devices for dispersion of the particles in the electrolyte.
A method of obtaining composite coatings of electrolytes, including effects on electrolyte containing solid submicroscale ultrasonic vibrations. Under the action of ULTRASONIC vibrations is diperkirakan conglomerates submicroscale to the level of initial formations or crystallites, thus increasing the viscosity of the electrolyte and increased sedimentation stability (EN No. 2088689, CL C25C 18/00, 1996).<> A method of obtaining composite coatings, offering to use colloidal cluster diamond particles with a size of 0.001-0,120 μm, the shape close to spherical or oval without sharp edges, in an amount of 0.1 to 35 g/l, which form a sedimentation and coagulation sustainable system in the electrolyte (RU # 2191227, CL C25D 15/00, 2000).
The drawback of these methods is that the sedimentation stability of the particles is provided defined by the shape and size of the particles, which significantly narrows the scope of the use of such an electrolyte.
A method of obtaining composite coatings of electrolytes, which is injected surfactant containing one amino group and one carboxypropyl or their mixture. Surfactant forms on the surface of the shell particles, preventing their agglomeration (RU # 1097718, CL C25D 15/00, 1982). A method of obtaining composite coatings comprising introducing into the electrolyte diamond particles treated with anionic wetting agent of the type that increases agglomeration resistant particles (GB No. 1391001, CL C25D 15/00, 1975). The disadvantage of the methods is that the surfactants and wetting agent adsorbed on the surface of dispersed particles, enters the coating material, affecting its physical and mechanical properties. In addition, surfactants and wetting, reducing the degree of agglomeration of the particles, do not provide endostatin dispersion in the electrolyte.
A method of obtaining composite coatings comprising preparing a suspension of ultradispersed diamond size up to 300 nm water-based with the addition of stearates and silicon dioxide. After mixing the ingredients, the suspension is injected into the electrolyte and carry out the electrolysis. The introduction of electrolyte additives allows to obtain a stable suspension of certain sizes of units (RU # 2094371, CL C25D 15/00, 1991). The disadvantage of this method is that introduced into the electrolyte additives during electrolysis, getting into the coating material, negative impact on the physico-mechanical characteristics of the coating.
A method of obtaining composite coatings comprising preparing a suspension of water-based, which after the introduction into it of the dispersed phase in the form of detonation diamond process for desegregation high sedimentation and coagulation stability on rotor-pulse or ultrasonic installation heated for 2 hours in hydrochloric acid, washed sediment from excess acid, then treated for 2 hours with a solution of caustic soda (RU # 2357017, CL C25D 15/00, 2007). The disadvantage of this method lies in the complexity and duration of the slurry preparation, significant loss of diamond powders in the preparation of the suspension.
A method of obtaining composite n the floor, comprising preparing a suspension of water-based, which is injected into the electrolyte. The suspension contains particles of synthetic diamond carbon material containing carbon in the form nuclei of ultradispersed diamond, surrounded by a shell containing x-ray amorphous carbon, and having on the surface of the particle surface functional groups containing oxygen, nitrogen and hydrogen (RU # 2404294, CL C25D 15/00, 2009). Diamond-containing material obtained by processing pre-dried powder of diamond-containing mixture which is a mixture of diamond and non-diamond forms of carbon with nitric acid at boiling within 2-5 hours, the Suspension is introduced into the electrolyte, provides a high dispersive capacity of the electrolyte. The disadvantage of this method lies in the complexity of the process of obtaining particles of synthetic diamond carbon material.
The closest way is to obtain a composite metalloorganic coatings from an electrolyte containing ultra-fine diamond powders with a specific surface area of 400-500 m2/g high degree of purification in the amount of 2-20 g/l (RU # 2156838, CL C25D 15/00, 1999). To obtain a homogeneous system of ultradispersed diamond powder is introduced into the electrolyte in the form of a suspension. A suspension is prepared from ultrafine diamond and electrolyte with concentration is the situation ultrafine particles 28-30%, then concentrate in a few tricks dilute electrolyte with thorough stirring to obtain a suspension with a concentration of ultradispersed diamonds 8-10%. The obtained suspension is injected into the electrolyte. The method allows easy enough to mix the ultra-dispersed diamond powders with electrolyte. The disadvantage of this method is that when mixing the suspension with a concentration of ultrafine particles 28-30% is disaggregation, i.e. ultrafine diamond particles constituting the aggregates of different sizes and different shapes, suspensions retain their original condition. In addition, the processing of ultrafine particles in the same electrolyte, in which electrolysis is carried out, not attached to the particles of the required sedimentation and coagulation stability.
The technical challenge is to create a method of producing composite coatings, allowing you to simply and efficiently perform the disaggregation of nanodiamond powders and give them high sedimentation and coagulation stability in the electrolyte, which allows to obtain coatings with a uniform distribution of the nanoparticles on the surface and the volume of coverage.
The technical solution of the problem is that in the process for electroplating composite coatings containing nasoalmo the nye powders, comprising preparing a suspension of nanodiamond powders and liquid phase, the introduction of the suspension into the electrolyte and electrolysis for the deposition of composite coatings, as a liquid phase to obtain a suspension take ethyl alcohol or acetone, with nanodiamond powders injected into the liquid phase in an amount of 60-80% vol. and perform disaggregation in suspension of nanodiamond powders by crushing and abrasion, after which the suspension is introduced into the electrolyte.
As the liquid phase is also possible to take an aqueous solution of ethyl alcohol or acetone.
The method consists in the following. Crushing and abrasion of nanodiamond powders produce, for example, in a vessel with curved bottom by priter. When high concentrations of nano-diamond powder in suspension, aggregative state which approaches pasty, disaggregation will occur not only due to the crushing and abrasive effects of priter powders on the sides and bottom of the vessel, but also the influence of aggregated nano-diamond powders on each other. It is not only a disaggregation of powders, but the simultaneous handling of ethyl alcohol or acetone to form on the surface of nanodiamond powders shell, caking of the particles in the electrolyte, which increases sedimentati is nnow stability of particles in a long time.
The method is as follows.
From nanodiamonds preparing a suspension containing ethyl alcohol or acetone. The number of nanodiamonds in the liquid medium should be 60-80%. At a concentration of nanodiamond suspension has a state of near pasty. The suspension is prepared mainly in a porcelain vessel, the bottom of which has a curved shape. For the disaggregation of nanodiamond particles their crushed and grated, for example, preterm, the shape of the working surface of which is similar to the shape of the bottom porcelain vessel. Crushing and abrasion produced manually or mechanized.
The electrolyte is prepared by dissolving metal salts in distilled water and work it under shock for 1 h Then an electrolyte is injected part. After mixing the components in a bath of the Nickel plating enter suspension with nanodiamonds. After that make electrolysis, in which the surface is deposited composite coating containing nano-diamond powders.
The concentration of 60-80% of nanodiamond powders in suspension provides effective disaggregation. At a lower content of nanopowders in suspensions in the past will be present a large amount of liquid phase, which will substantially increase the complexity of disaggregation of nanopowders and possible partial dezagregare the interview. Increasing the concentration of nano-powders in suspension will greatly reduce the amount of liquid phase is ethyl alcohol or acetone, with a small number of these components will not be sufficient for effective wetting of nanodiamond powders and education sheath that prevents them from sticking together in the electrolyte and provide sedimentation stability.
Ethyl alcohol and acetone, in contrast to the electrolyte, well moisten diamond powders and spreading on the surface of nanodiamond particles penetrate inside the unit. Simultaneously, ethyl alcohol and acetone interact with polar functional groups adsorbed on the particles of the diamond, forming on their surfaces positively charged membrane, which provides a wedging action on the particles prevents their aggregation in the electrolyte and on the electrophoretic mechanism contributes to the movement of particles to the cathode. Crushing and abrasion of nanodiamond powders in an aqueous solution of ethyl alcohol or acetone allows you to more effectively and efficiently to produce the dispersion of powders in a short time.
In addition, introduced into the electrolyte ethyl alcohol or acetone, which is the liquid phase in suspension work in the electrolyte as a leveling additive, allowing for smooth high-quality coverage. If neo is needed, ethyl alcohol and acetone can be introduced into the electrolyte additionally in the required amount.
Ethyl alcohol and acetone in a suspension can be used in the form of 70-80% water solution. The use of aqueous solutions of these components is more economical.
Under the proposed method produced diamond tools - diamond tube drills.
In the diamond tool of the composite coating is a material retaining workers of diamond grains on the body of the tool.
In a vessel with a curved bottom was preparing two suspensions containing nanodiamond powders and liquid phase. In the same suspension as the liquid phase used an aqueous solution of ethyl alcohol, another aqueous solution of acetone. The concentration of nanodiamond powders were 60-80 vol.%. Preterm manually crushed and rubbed aggregates of nano-diamond powders for 15 minutes. The result has been close to the pasty state of a homogeneous mass of nanodiamond powders without conglomerates, clots, etc.
Prepared two baths of the following composition:
Nickel sulfate 7-water and 300 g/l
Nickel duplissy 6-water - 50 g/l
Boric acid 40 g/l
The first bath was carried out by attaching and partial silting on the housing of the working tool diamond powder grain 125/100 layer of Nickel values is 20 microns.
The tool body part is overgrown with partially into the first tub working diamond powders were draped in the second tub. The electrolyte was introduced to one of the suspensions were thoroughly mixed and produced by electrolysis before the deposition of the layer composite coating to silting working diamond powders on the value of 70-80% of their size. The number of nanodispersed powder in the coating is regulated by the amount introduced into the electrolyte suspension.
Received the tool, in which the matrix finally sarasaviya working diamond powders on the tool body, was a composite coating containing nano-diamond powders. The coating had a uniform thickness of sediment. To determine the quality of galvanic coatings containing nano-diamond powders, the coating was applied on a specially prepared foil and the surface was examined with an electron microscope (photos, pictures in dark field and their Fourier images). The surface had a low uniform roughness for the given current density, nano-diamonds were found in the structure of the Nickel coating in the form of agglomerates. Use ethyl alcohol or acetone led to a decrease in the number of agglomerates and to a more uniform distribution of the particles in the structure of the Nickel cover the Oia.
Thus, the introduction into the electrolyte nanodiamond powders by means of preliminary preparation of suspensions with a high content of nano-diamond powders in the liquid phase of ethanol or acetone allowed to provide effective disaggregation of nanodiamond powders and to obtain a coating with high physical-mechanical properties due to high sedimentation and coagulation stability of the particles in the electrolyte.
A method of obtaining a composite electroplating coatings containing nano-diamond powders, comprising preparing a suspension of nanodiamond powders and liquid phase, the introduction of the suspension into the electrolyte and electrolysis for the deposition of composite coatings, characterized in that the liquid phase to obtain a suspension take ethyl alcohol or acetone, with nanodiamond powders injected into the liquid phase in an amount of 60-80% vol. and perform disaggregation of powders in suspension by crushing and abrasion by Pitirim, after which the suspension is introduced into the electrolyte.
SUBSTANCE: proposed method comprises electrolytic plasma oxidation in aqueous electrolyte containing PTFE powder particles. Note here that oxidation is performed in galvanostatic conditions at current density of 0.03-0.05 A/cm2 for 20-30 min in alkaline electrolyte containing 40-60 g/l of PTFE powder and, additionally, it comprises siloxane-acrylate emulsion in amount of 40-100 ml/g.
EFFECT: higher electrolyte stability, better wear resistance and hydrophobic properties of coatings.
2 cl, 8 ex, 5 dwg
FIELD: electrical engineering.
SUBSTANCE: according to the method, one introduces into the electrolyte nano-dispersed chrome diboride powder with particle size 40-70 nm and oxidation no more than 12·10-7 kg of oxygen /m2 of the surface in an amount of 6-10 kg/m3 and in the form of an electrolyte-and-powder paste with chrome diboride content no more than 65 wt %, such paste having undergone ultrasonic treatment at s frequency no less than 20 kHz; then the coating is sedimented at a temperature of 323-333 K and cathode current density equal to 0.9-1.0 kA/m2 and annealed in vacuum at a temperature of 873-1073 K during 50-75 min.
EFFECT: improved microhardness, wear resistance, corrosion resistance of the coating combined with reduction of its production costs.
FIELD: electrical engineering.
SUBSTANCE: component parts are loaded into a bathtub containing an electrolyte formulated as follows, kg/m3: FeCl2*4H2O - 500-550, Na2H4C4O6*18H2O - 1.5-2, Grade M14 boron carbide - 80-120, pH=0.5-1.2, at a temperature of 40-80°C. The electrolyte acidity in the process of sedimentation is corrected within the range of pH=0.7-0.9. Then one performs thermal treatment with HF currents to ensure a temperature equal to 500-600°C at a depth equal to the applied layer thickness.
EFFECT: enhanced strength and wear-resistance of component parts coatings being recovered and reinforced.
SUBSTANCE: electrolyte suspension contains the following, g/l: nickel sulphamate - 250-300; nickel chloride - 15-20; boric acid - 25-40; terafluoroethylene and ethylene copolymer powder - 110-200; 4,6-disulphoisophthalic acid diimide - 0.4-0.8; sulphosalicylic acid - 0.1-0.2; surfactants - 3.5-6 and water - the balance.
EFFECT: high rate of coating deposition and low coefficient of friction.
1 tbl, 1 ex
SUBSTANCE: proposed method comprises introducing quasicrystalline AlCuFe powder into nickel solution and applying coating on article surface. Note here that coating is deposited at 18-22°C and mixed in the presence of nonionic surfactants OC-20 or synthalon ALM-10 using nickel anodes at the following ratio of components, g/l: NiSO4·7H2O 25-30; NH4Cl 28 - 30; Na2SO4 16 - 20; SA 0.013 - 0.014; quasicrystalline power - not exceeding 70. Note here that mean particle size of quasicrystalline powder makes 6.0 mcm.
EFFECT: simplified process, lower costs.
2 cl, 1 tbl, 4 dwg
SUBSTANCE: method involves introduction to electrolyte of disperse phase in the form of solid submicroparticles; at that, introduction is performed in the form of effervescent soluble tablets consisting of Taunit nanocarbon material 1.6 to 8.3 wt %, surface active substance - polyvinyl pyrrolidone 8 to 16 wt %, sodium bicarbonate 30 to 50 wt %, and citric acid 10 to 50 wt %.
EFFECT: obtaining galvanic coatings with high microhardness, wear resistance and low porosity.
3 cl, 1 tbl, 2 ex
SUBSTANCE: method involves deposition of the coating from electrolyte containing deposited metal ions and hardening additives in a suspended state; hardening additives are added in the quantity that is determined as per the following equation: where z - quantity of hard inclusions in the coating, %, f1 - coating friction coefficient without inclusions, f2 - coating friction coefficient with inclusions, λ1 - heat conductivity of the coating without inclusions, W/m·K, λ2 - heat conductivity of the coating with inclusions, W/m·K.
EFFECT: increasing wear resistance of electrolytic coatings and reducing labour intensity for obtaining coatings owing to reducing the number of investigations.
2 tbl, 1 ex
SUBSTANCE: proposed invention can be used for application of composite electrolytic coatings from silver, which contain detonation synthesis ultradispersed diamonds (DSUD), to products from steel, bronze and other metals. The above method also involves introduction to dicyanoargentate silver-coating electrolyte of water suspension with DSUD and electric deposition of the coating on products; at that, prior to introduction of DSUD suspension to the electrolyte, it is treated with electrohydraulic impacts, clarified and added to the electrolyte, without any penetration of the deposit; after that, sine-wave alternating asymmetric voltage is supplied to electrodes with the half-period equal to application of single monoatomic coating layer, with the ratio of anode and cathode currents and equals to 1.2; 2.0; 4.0; 6.0; 8.0; 10.0, and by performing the successive electric deposition for at least two ratios with one hour each; at that, the coating thickness is determined during application process by weighing the product, and electric deposition is stopped when the specified thickness of the coating is achieved.
EFFECT: increasing DSUD surface activity, strength and durability of electrolytic coatings.
3 cl, 1 ex
SUBSTANCE: method involves microarc oxidation of surface of products from titanium alloys in alkaline electrolyte with solid-phase ingredients in the form of powders; at that, nanopowders of titanium oxide with size of less than 0.05 mcm are used, and final coating is formed at cathodic treatment in acid electrolyte at temperature of 450°C by deposition of metallic phase inside pores of oxide coating.
EFFECT: improvement of microhardness of coatings and corrosion resistance of products due to reduction of porosity is provided.
1 tbl, 1 ex
SUBSTANCE: method involves micro plasma oxidation in pulse anodic-cathodic mode with duration of groups of anodic pulses of 50 ms, cathodic pulses of 40 ms, pauses between them of 10 ms and ratio of average anodic and cathodic currents of 1.1 : 0.9 in water solution of electrolyte, which consists of three solutions, series oxidation in them during 10 minutes, at the following component ratio, g·l-1, in the first solution: sodium hydroxide 0.3-0.5, sodium metasilicate 3.0-4.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0; in the second solution: sodium hydroxide 0.8-1.0, sodium metasilicate 6.0-8.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0; in the third solution: sodium hydroxide 1.8-2.0, sodium metasilicate 11.0-15.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0.
EFFECT: simplification of the technology of the process for obtaining oxide composite coatings; increasing corrosion resistance, wear resistance and antifriction properties of aluminium surface and its alloys.
1 tbl, 1 dwg, 2 ex
SUBSTANCE: method includes electrolytic dissolution of at least one anode made of silicon into a melt of a mixture containing the following components, wt %: 0 ÷ 70 CsCl, 10 ÷ 60 KCl, 10 ÷ 45 NaCl, in an electrolytic cell under inert atmosphere, in the range of temperatures from 600 to 700°C at cathode density of current from 0.3 mA/cm2 to 100 mA/cm2 with release of alkaline metals on the cathode and recovery of silicon compounds in the melt volume.
EFFECT: production of electrolytic crystalline or X-ray amorphous silicon in the form of nano- and microstructural powders or fibres with high specific surface.
FIELD: process engineering.
SUBSTANCE: invention relates to powder metallurgy, particularly, to production of open-pore nano-structured metal. It may be used in data write and store systems, various magnetic systems, as carriers of various pharmaceutical preparations for directed transfer of medicines in magnetic fields, etc. Solution of iron sulphate and nickel chloride hexahydrate salts are heated to 80-90°C. Metals are deposited as iron and nickel hydroxides by adding sodium hydroxide to solution at continuous mixing of sodium hydroxide. Then, 20-30 ml of 65 wt %-hydrazine hydrate is added to the solution and held for 5-20 minutes.
EFFECT: single-fraction mono-dispersed powder with high content of metal phase.
3 cl, 2 dwg, 1 tbl, 17 ex
SUBSTANCE: device (50) for preparation of nanoparticles on a continuous basis comprises the first feeding device (1a) with the first feeding load (9) connected to the source (7) of the starting material, the first reactor (2) comprising the first heated reaction zone (13), the second reactor (3) comprising the second heated reaction zone (15), where all the said devices are connected to the channel of the material flow successively in the said order, at least one pressure control unit (18) mounted in the said channel of the material flow, a mixer (5) mounted in the said channel of the material flow between the first reactor (2) and the second reactor (3), the second feeding device (lb) with the second feeding pump (10) connected to the source (8) of the starting material, and the second feeding pump (10) is in liquid junction with the mixer (5), the control device (22) made with the ability to control the pressure value setting with the said pressure control unit (18) and/or the temperature value of the said heated reaction zones (13 and 15). The device is characterised in that after each heated reaction zone (13) in the channel of the material flow the appropriate cooling device (14, 16) is mounted for reducing the size of the nanoparticles in the process of their preparation, and the cooling devices (14, 16) are additionally made with the ability to cease this process of nanoparticles preparation. Also the invention relates to use of the device for preparation of nanoparticles/nanoemulsions/colloidal solutions.
EFFECT: invention enables to obtain nanoparticles which properties can be modified in the course of this process.
8 cl, 10 dwg
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to a powdered preparation for soft tissue regeneration with an antibacterial effect. The preparation contains 0.07-0.09 wt % of copper nanoparticles sized 30-40 nm, 0.03-0.05 wt % of zinc nanoparticles sized 30-70 nm, and low-molecular chitosan.
EFFECT: invention improves the effectiveness of wound healing, including in septic and infected ones, while simplifying the processes of preparing and using the preparation, and also prolonging a shelf life thereof.
2 cl, 3 ex
FIELD: measurement equipment.
SUBSTANCE: method is proposed to manufacture a vacuum sensor with a nanostructure, consisting in the fact that a thin-film semiconductor resistor is formed in the form of a meshy nanostructure (SiO2)50%(SnO2)50% by application of a sol of orthosilicic acid containing a stannum hydroxide, onto a silicon substrate with the help of a centrifuge and subsequent baking. The sol is prepared in two stages, at the first stage tetraetoxysilane and ethyl alcohol are mixed, then at the second stage distilled water is added to the produced solution, as well as hydrochloric acid (HCl) and stannum chloride dihydrate (SnCl2·2H2O). The vacuum sensor with the nanostructure made according to the proposed method comprises the body, the heterogeneous structure installed in it from thin films of materials, formed on the substrate of a semiconductor, the thin-film semiconductor resistor and contact sites to it, formed in the heterogenerous structure, leads of the body and contact conductors, which connect contact sites with body leads.
EFFECT: increased sensitivity of a vacuum sensor.
5 cl, 4 dwg
SUBSTANCE: metal strip contains a coating from carbon nanotubes and/or fullerenes soaked with metal chosen from the group consisting of Sn, Ni, Ag, Au, Pd, Cu, W or their alloys. Method for obtaining metal strip with the coating from carbon nanotubes and/or fullerenes and metal involves the following stages: a) application of diffusion barrier layer from transition metal Mo, Co, Fe/Ni, Cr, Ti, W or Ce onto a metal strip, b) application of a nucleation layer from metal salt containing metal chosen from the group Fe, the 9-th or the 10-th subgroup of the periodic table onto the diffusion barrier layer, c) introduction after stages a) and b) of treated metal strip to hydrocarbon atmosphere containing organic gaseous compounds, d) formation of carbon nanotubes and/or fullerenes on metal strip at temperature of 200°C to 1500°C, e) soaking of carbon nanotubes and/or fullerenes with metal chosen from the group containing Sn, Ni, Ag, Au, Pd, Cu, W or their alloys.
EFFECT: obtained metal strip with the coating has improved friction coefficient, increased transition resistance of a contact, increased resistance to friction corrosion, improved resistance to abrasion and increased ability to be deformed.
SUBSTANCE: invention can be used to make damping elements, shock absorbers, friction pairs and wear-resistant components of micromechanisms. Starting carbon material is placed in a working volume; nitrogen is pumped and removed until complete displacement of air. At the first step, nitrogen is pumped to working pressure of 220-250 MPa, heated to 1670-2020 K and held for not less than 1 minute. Temperature is then lowered to room temperature and pressure is lowered to atmospheric pressure. At the second step, the obtained carbon-nitrogen material is treated in a high-pressure apparatus at pressure of 7-15 GPa and temperature of 1620-1770 K for not less than 1 minute. Temperature is then lowered to room temperature and pressure is lowered to atmospheric pressure. The starting carbon material used is fullerites, for example C60 and/or C70, which are first ground to particle size smaller than 1 mcm in order to increase content of nitrogen in the finished material.
EFFECT: invention enables to obtain a compact carbon-nitrogen material with a bulbous structure, which contains 2,2-5,0 at % nitrogen, having Young's modulus of 43-67 GPa, microhardness of 5,4-8,2 GPa and hyperelastic recovery parameter of 92-97%.
3 cl, 5 dwg, 4 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers to a method for preparing stabiliser-coated nanocrystalline cerium dioxide characterised by antioxidant activity. The method involves preparing an aqueous solution of cerium salt and a stabiliser representing maltodextrin with a molar ratio of cerium to the stabiliser 1 to 1-4. Then, the prepared aqueous solution is added with drops of hydrous ammonia with stirring, and pH of the prepared solution is gradually increased to 7-8, maintained for 1-4 hours, the prepared colloidal solution of hydrous cerium nanoparticles is added with hydrous ammonia, and pH is increased to 11-12 and maintained for 1-10 hours to form a colloidal solution of cerium dioxide. Thereafter, an alcohol or ketone excess is removed and brought to the boiling point, while the formed precipitate of the non-aggregated nanoparticles of stabiliser-coated cerium dioxide, separated by decantation or filtration, washed 1-4 times in alcohol or ketone, and dried at temperature 50-80°C to constant weight. The prepared powder of the non-aggregated nanoparticles of stabiliser-coated cerium dioxide is re-dispersed in a polar solvent to form aggregation resistant sol.
EFFECT: invention provides preparing stabilised nanocrystalline cerium dioxide with a hydrodynamic diameter of 6-10 nm.
3 cl, 7 dwg, 4 ex
FIELD: electrical engineering.
SUBSTANCE: invention may be used for production of individual crystals of zinc oxide and arrays thereof for application as active elements, material for photocatalytic water treatment, piezoelectric sensors as well as for fundamental physical studies of crystal growth kinetics. Crystals are grown in the air using a continuous action ytterbium fibre laser with yellow metal surface with a layer of multi-walled carbon nanotubes applied thereon treated with such laser radiation with power density equal to approximately 105 W/cm2 during 10 sec. The method enables production of micro- and nanostructured zinc oxide arrays consisting of filamentary crystals, microplates and druses.
EFFECT: invention enables crystals production without special catalysts or crystallisation chambers.
SUBSTANCE: fluoride nanoceramic is obtained by thermomechanical treatment of the starting crystalline material made from CaF2-YbF3, at plastic deformation temperature to obtain a workpiece in form of a polycrystalline microstructured substance, which is characterised by crystal grain size of 3-100 mcm and a nanostructure inside the grains, by annealing on air at temperature of not less than 0.5 of the melting point with compaction of the obtained workpiece in a vacuum at pressure of 1-3 tf/cm2 until the end of the deformation process, followed by annealing in an active medium of carbon tetrafluoride at pressure of 800-1200 mmHg. The starting crystalline material used can be a fine powder which has been subjected to heat treatment in carbon tetrafluoride, or a moulded workpiece of crystalline material made from the powder and heat treated in carbon tetrafluoride.
EFFECT: invention enables to obtain a fluoride nanoceramic with high degree of purity and high uniformity of the structure of said optical material.
4 cl, 3 ex
SUBSTANCE: invention relates to medicine and deals with nanoliposome which includes liposomal membrane, contains ethgerificated lecitin and one or more physiologically active ingredients, incorporated in the internal space of liposomal membrane, method of obtaining such, as well as composition for prevention or treatment of skin diseases, containing nanoliposome.
EFFECT: invention ensures long-term stability and homogenecity of nanoliposomes.
15 cl, 22 ex, 4 dwg, 2 tbl