Method of producing nanodispersed metal oxides
SUBSTANCE: method of producing nanodispersed metal oxides involves forming a reaction mixture by introducing metal and carbamide nitrates into the aqueous medium in a stoichiometric ratio. The reaction medium is exposed to microwave radiation. The reaction mixture is formed directly in the reaction volume at the following component ratio, wt %: a mixture of nitrate and carbamide 10-20, water - the rest. The exposure to microwave radiation is carried out with open access to the reaction medium in the reaction volume. The intermediate reaction product is dried at a temperature of, at least, 200°C. The dried product is ground to a particle size of not more than 20 nm. During the grinding of the dried product, a hydrophobizing treatment is carried out in parallel with a hydrophobizing mixture consisting of silanes and silicone oligomers taken in the ratio, wt %: silane 17-33, silicone oligomer 67-83.
EFFECT: complete conversion of metal nitrates to oxides having prolonged resistance to agglomeration, increasing the yield of products, excluding the presence of traces of the original components in the products.
4 cl, 6 tbl, 8 ex
SUBSTANCE: invention relates to technology of obtaining zinc oxide and can be applied for obtaining zinc oxide with displaced isotopic composition. Method includes obtaining zinc hydroxide from diethylzinc, which is carried out in flow-type reactor in water or water pulp stream, containing zinc hydroxide, with consumption of diethylzinc up to 40 kg and hour with obtaining pulp, which contains zinc particles. Pulp is subjected to separation to separate it from reaction gases and re-supplied into reactor as hydrolysing agent. After pulp saturation zinc hydroxide is separated from water by settling. Zinc hydroxide is dried and decomposed to zinc oxide.
EFFECT: process safety which is achieved due to instant removal of heat and reaction products by water stream.
SUBSTANCE: method of making a planar waveguide of zinc oxide on lithium niobate involves preparing a film-forming solution, holding said solution for 1 day at room temperature, depositing the solution on polished lithium niobate, drying, annealing and gradually cooling in natural cooling conditions of a muffle furnace. The lithium niobate is pre-treated with 96% ethyl alcohol solution. The lithium niobate with the deposited film-forming solution is dried at 60°C for 1 hour, followed by annealing at 400°C in an air atmosphere at heating rate of 14°/min for 1 hour and at 870-1050°C at heating rate of 35°/min for 2-5 hours, with the following ratio of components of the film-forming solution, wt %: zinc nitrate crystalline hydrate 5.2-9.9%; salicylic acid 4.6-4.8%; 96% ethyl alcohol solution - the balance.
EFFECT: invention reduces labour consumption and power consumption of the process of making a planar waveguide which is resistant to radiation in the green spectral region and has maximum refraction index increment values.
1 dwg, 2 tbl, 3 ex
SUBSTANCE: invention relates to opto- and microelectronics and can be used to make opal-like structures. The method of producing photonic-crystal structures based on metal oxide materials involves filling a template consisting of monodispersed micropheres of polystyrene, solutions of metal-containing precursors, followed by annealing the structure on air at temperature of 450-550°C for 8-10 hours. The precursors from which the structure is formed are saturated alcohol solutions of tin dichloride SnCl2·2H2O or zinc nitrate Zn(NO3)2·2H2O.
EFFECT: invention enables to obtain photonic-crystal structures based on SnO2 and ZnO with a photonic stop band in the visible or near infrared spectral range and porosity of not less than 85%.
SUBSTANCE: invention relates to the technique of producing Zn64 isotope impoverished zinc oxide, purified from tin and silicon impurities, which is currently used as an additive in water coolant of the primary loop of nuclear reactors. Zn64 impoverished zinc oxide powder is obtained from Zn64 impoverished diethylzinc, dissolved in aqueous acetic acid solution with weight ratio of reactants zinc oxide: water: acetic acid equal to 1:(1.6-2.0):(1.8-2.2). The obtained solution is evaporated to oversaturation - formation of a dense crust of zinc acetate, gradually cooled to 25-30°C and then held for 15-20 hours. The zinc acetate crystalline hydrate precipitated from the solution is filtered and undergoes thermal decomposition in air to zinc oxide at 600-800°C for 4-6 hours.
EFFECT: invention reduces content of tin and silicon in the commercial product to less than 10-3 % and cuts the number of process steps.
SUBSTANCE: invention can be used in chemical industry. The method of producing zinc oxide involves grinding zinc metal powder, treating with a reaction mixture containing ammonia and calcining the obtained mass. The reaction mixture used is ammonium carbonate solution. Treatment with the reaction mixture is carried out in weight ratio of components Zn: ammonium carbonate solution equal to 1:(1-2), and the obtained material is calcined at 240-310°C.
EFFECT: invention increases specific surface area of zinc oxide.
1 tbl, 3 ex
SUBSTANCE: method of producing zinc oxide powder by oxidising zinc with oxygen while heating, where zinc metal first undergoes distillation at temperature lower than boiling point in a stream of an inert gas; the obtained powder is oxidised in a revolving reactor with a controlled atmosphere at temperature lower than the boiling point of zinc.
EFFECT: invention enables to obtain zinc oxide powder containing less impurities than the starting metal using commercial-grade zinc metal and industrial oxygen as starting materials.
SUBSTANCE: invention relates to the technology of producing zinc oxide depleted of the Zn64 isotope, used as an additive in nuclear reactor cooling systems. The zinc oxide is produced in a liquid phase medium. Diethylzinc is diluted with hexane in volume ratio 1: (12-16). Further, water is added to the mixture in excess of 10-30% of the stoichiometric amount. The obtained zinc hydroxide is dried at temperature 120-170°C for 3-4 hours and then decomposed to zinc oxide at temperature 350-400°C for 15-19 hours.
EFFECT: invention increases zinc oxide output to 99% and strength and density of tablets made from said zinc oxide.
2 dwg, 3 ex
SUBSTANCE: invention relates to production of thin-film materials used in illumination, construction and electronics. The composition for making thin films based on a system of double oxides of zirconium and zinc contains the following components, wt %: zirconium oxochloride 4.0-8.6; zinc nitrate 3.8-7.6; pre-distilled and dried to 96 wt % ethyl alcohol - the rest. The film-forming solution of the said composition is deposited onto a substrate by centrifuging and subjected to step-by-step thermal treatment.
EFFECT: invention enables to obtain thin films having high refraction indices and a stable structure.
1 tbl, 3 ex
SUBSTANCE: invention relates to production of zinc oxide depleted of the Zn64 isotope, used as an additive in nuclear reactor cooling systems. Zinc oxide powder obtained through hydrolysis of Zn64 isotope-depleted diethyl zinc is washed with high purity hexane in amount of 0.005-0.006 m3 per kg of zinc hydroxide, then dried at temperature 120-160°C for 12-16 hours and calcined at temperature 340-370°C for 14-16 hours.
EFFECT: invention enables to lower content of tin impurities in zinc oxide to less than 10-3 wt % and carbon impurities to less than 0,025 wt %.
SUBSTANCE: invention can be used in production of materials which can protect from thermal radiation. The zinc oxide contains 0.25-25 wt % gallium and has charge carrier density ne equal to or greater than 2×1020/cm3 and charge carrier mobility µ ranging from 0.1 to 40 cm2/V-s. A thin film of the said gallium-containing zinc oxide has thickness equal to or less than 5 mcm, as well as degree of transmitting solar radiation Ts and degree of transmitting visible optical radiation Tv which satisfy the inequality Ts ≤ 1.4Tv-39. The thin film of gallium-containing zinc oxide satisfies the condition Y ≥ 0.4X+1.06 for film thickness equal to or greater than 400 nm and the condition Y ≥ 0.2X+0.98 for film thickness equal to or less than 300 nm, where X is charge carrier density of 10-20/ charge carrier mobility and Y equals Tv/Ts.
EFFECT: invention enables to obtain gallium-containing zinc oxide having thermal radiation protection properties while retaining high transparency for visible optical radiation.
22 cl, 10 dwg, 6 tbl
SUBSTANCE: method comprises production of the nickel oxide powder from metal nickel electrodes by electrolysis in basic solution of sodium hydroxide. Process is executed at temperature 20-30°C upon simultaneous action on the electrodes of current with frequency 20 Hz. At that electrolysis is performed at asymmetrical alternating current with current density of anode and cathode half cycle 2.5 A/cm2 and 1 A/cm2, respectively, and at action on the electrodes of the ultrasound radiation with frequency from 150 to 300 kHz.
EFFECT: production of ultra-micro-dispersed powder of nickel oxide suitable for use during catalitic production of nano-carbon materials with maximum production of the target product, decreasing of power consumption.
SUBSTANCE: method of producing ultramicrodispersed nickel oxide powder includes electrolysis in 17 M sodium hydroxide solution under alternating sinusoidal current at 20Hz with nickel electrodes. The process of electrolysis is carried out at temperature of 20-30°C and voltage across the electrodes of 4V.
EFFECT: method for producing ultramicrodispersed nickel oxide powder suitable for use in catalytic production of nanocarbon materials by pyrolysis of hydrocarbons while reducing heating costs and simplifying its cell structure.
SUBSTANCE: invention can be used in chemical industry. The method of producing nickel (II) hydroxide involves treatment of an acidic solution of nickel (II) sulphate in two steps, at the first step with ammonia water to pH 4-4.5, at the second step with sodium hydroxide to pH 11-12. At the second step, the process is carried out by feeding the suspension from the first step into the sodium hydroxide solution. Further, impurities are washed off from the residue in an ascending stream with variable hydrodynamic conditions. The residue is then pressed and dried.
EFFECT: invention increases purity of the product and uniformity of its grain-size distribution.
3 cl, 3 tbl, 3 ex
FIELD: power engineering.
SUBSTANCE: method to produce a composite NiO/C material containing 15-60% NiO and representing crystallites β-NiO evenly distributed on a carbon carrier surface with the average size of 2-5 nm, is based on production of NiO nanoparticles as a result of electrochemical oxidation and destruction of two nickel electrodes in solutions of alkaline metal hydroxides with concentration of 2 mole/l under action of AC current with frequency of 50 Hz at average value of current referred to a unit of electrode surface area making 0.3-1.5 A/cm2, with simultaneous deposition of produced nickel oxide nanoparticles onto the carbon carrier, subsequent filtration of the produced suspension, washing of composite by distilled water and its drying at 80°C for 1 hour.
EFFECT: invention makes it possible to increase quality of produced material due to absence of admixtures and to reduce costs for its production.
FIELD: process engineering.
SUBSTANCE: invention relates to device and method of producing compounds by precipitation of solid substances. Proposed device comprises reactor provided with inclined settler. Proposed method comprises mixing initial substances in reactor, precipitation of compounds in reaction zone, partial separation of mother leach from precipitated product in inclined settler, separation of product suspension, its filtration and drying. Invention covers also mixed powder of nickel-cobalt hydroxide with WET-surface of less than 20 m2/g and impact density exceeding 2.4 g/cm3.
EFFECT: suspension with concentration exceeding stoichiometric one.
29 cl, 13 dwg, 5 ex
SUBSTANCE: iron oxide pigment contains α-modified iron (III) oxide with a plate-like crystal shape. Content of Fe2O3 in the pigment is 97-99 wt %. The crystals have average diameter of 0.1-0.8 mcm, with the ratio of the diameter to the thickness of the crystals of 0.1-0.2. The method of producing iron oxide pigment includes oxidative hydrolysis of aqueous iron (II) sulphate solutions at 10-40°C, followed by hydrothermal treatment of the formed products in an alkaline medium at 150-250°C. Hydrolysis of the suspensions obtained from the aqueous iron (II) sulphate solutions is carried out at pH=10-13, and oxidation is carried out with hydrogen peroxide.
EFFECT: invention reduces the average size of iron oxide crystals for use in paint compositions with low viscosity of the binder, particularly in water-dispersed compositions.
2 cl, 1 tbl, 7 ex