38results about How to "Narrow diameter distribution" patented technology

The production method for cerium oxide particles of the present invention is a method of producing a cerium oxide particle by heating a cerium compound from a normal temperature to a temperature range of 400° C. to 1200° C., and comprises at least a temperature raising stage of a temperature rise speed of 2° C./hour to 60° C./hour, or proceeds via a stage of heating while supplying a humidified gas in a temperature raising process. By the method of the present invention, a cerium oxide powder whose particle diameter distribution of primary particles is narrow can be obtained. An aqueous cerium oxide slurry produced from the powder enables an improvement in the productivity and a reduction in the cost of a polishing step, because if it is used as an abrasive a high-quality polished face is obtained without deteriorating the polishing speed. The aqueous cerium oxide slurry of the present invention is particularly useful as an abrasive for final finish of a substrate whose main component is silica.

The invention discloses an artificial blood vessel stent with aligned fibers and a manufacturing method of the artificial blood vessel stent, and belongs to the field of tissue engineering. According to the artificial blood vessel stent provided by the invention, a bio-compatible polymer material is taken as a spinning solution; firstly, the influence of different rotating speeds on fiber alignment is researched by virtue of an electrostatic spinning method, so that a rotating speed that the best alignment degree is achieved is determined; and then, the aligned fiber artificial blood vessel stent is manufactured on the basis of the rotating speed; the artificial blood vessel stent is relatively good in biocompatibility; and in addition, the alignment of smooth muscle cells on blood vessels can be guided. The artificial blood vessel stent provided by the invention is applicable to large-scale production and is expected to be applied to actual clinical diagnosis.

The invention relates to massive and controllable preparation field of semiconductor type single-walled carbon nanotubes, specifically to a method for directly growing the semiconductor type single-walled carbon nanotube with floating catalyst and auxiliary oxygen. The method comprises the following steps of: taking ferrocene as precursor of the catalyst, taking right amount of sulphur powder as growth promoter, and taking hydrogen as a carrier gas; simultaneously introducing a carbon source gas and small amount of oxygen to grow the single-walled carbon nanotube, and etching the small-diameter and metallic single-walled carbon nanotube in situ; and finally, obtaining a sample in which the semiconductor type single-walled carbon nanotube is dominant, wherein content of the semiconductor type single-walled carbon nanotube is 90 wt%, and diameter distribution of the semiconductor type single-walled carbon nanotube is 1.4-1.8 nm. With the method, massive and directly controlled growth ofthe semiconductor type single-walled carbon nanotube with narrower diameter distribution is realized; and the method solves the problems, such as that the separation process of the existing chemical and physical methods seriously damages the intrinsic structure of the single-walled carbon nanotube and the process is complex, and sample amount is less, diameter distribution is wider and the diameter is smaller in the direct preparation technology, and the like.

The invention discloses a preparation method of gallium nitride nanowires. The method comprises the steps of loading Ga2O3 and GaN as a mixed gallium source into a small porcelain boat, placing a Si substrate material plated with a catalyst Ni layer or Au layer into a quartz tube, and placing the small porcelain boat into the quartz tube, wherein a distance from the center of the mixed gallium source to the center of the Si substrate material is 10-20cm; then placing the quartz tube into a tube furnace while enabling the small porcelain boat to be aligned with the center of the tube furnace, heating to 1100 DEG C at 30-35 DEG C/min, introducing Ar gas at 20sccm during heating and keeping for 31-37min, stopping introducing the Ar gas, introducing NH3 gas at 15-45sccm and keeping for 15-30min, stopping introducing the NH3 gas and introducing Ar gas again, and cooling naturally to room temperature, wherein faint yellow substances formed on the surface of the Si substrate material are gallium nitride nanowires. The gallium nitride nanowires prepared by the method have high crystal quality, and the preparation process has good controllability.

The invention discloses a dispersing, mixing and drying device, comprising a stand, a vibration exciter mounted on a base of the stand, an electric motor driving the vibration exciter to operate, and a grinding barrel located inside the stand and mounted on the base of the stand via a vibration reduction spring. The grinding barrel is filled with grinding medium therein, the vibration exciter acts on the grinding barrel, the grinding barrel can be vacuumized or be used for heating and cooling the medium therein via a jacket arranged at the periphery of the grinding barrel. The materials at a discharging hole can be circularly fed into a feeding hole repeatedly via a material pipeline to be mixed and dispersed. The invention can enable the materials to be evenly dispersed and dried within a short time so that a desired crushing result is achieved.

The invention relates to the field of single-wall carbon nanometer tubes, in particular to a method for obtaining a large number of semi-conductive single-wall carbon nanometer tubes through combining post treatment oxidation with chemical gas-phase deposition in-situ weak oxidation. Trace oxygen is introduced in the process of chemical gas-phase deposition growth of the singe-wall carbon nanometer tubes, and then, the prepared single-wall carbon nanometer tubes are oxidized in the air at the proper temperature. Ferrocene is used as a catalysis precursor, hydrogen is used as carrying gas, sulfur powder is used as growth promoters, carbon source gas and trace oxygen are simultaneously introduced at a certain temperature for carrying out the growth and in-situ weak oxidation of single-wall carbon nanometer tubes, the obtained single-wall carbon nanometer tube samples are oxidized for a long time in the air atmosphere at the low temperature, and the oxidized samples are soaked into hydrochloric acid solution to remove catalyst particles, are cleaned and dried. The method realizes the mass preparation of the single conductive (semi-conductive) single-wall carbon nanometer tubes and solves the problems that the damage to the intrinsic structure of the single-wall carbon nanometer tubes in the existing chemical and physical method separation process is serious, and the like.

The invention discloses a preparation method of a high-purity silver nanowire. The method comprises steps of step 1, preparing silver nanowire synthetic liquid; 2, uniformly stirring the obtained silver nanowire synthetic liquid and solvent, and centrifuging to obtain silver nanowire precipitate; and 3, uniformly stirring the obtained silver nanowire precipitate and the dispersion solution, and separating and purifying through a multi-stage filtering device to obtain the silver nanowire. The method is advantaged in that high-speed centrifugation and step-by-step filtration are combined, the separation process is simple, efficient, safe and environmentally friendly, the silver nanowires obtained through separation are high in purity, narrow in diameter distribution range, good in dispersityand not prone to agglomeration, and a coated silver nanowire conductive film has advantages of high light transmittance, low haze, low sheet resistance and the like.

The invention relates to a preparation method of composite microspheres, in particular to the preparation method of the composite microspheres which are obtained by using acrylamide as well as acrylic acids and derivatives thereof as monomers and carrying on multivariate copolymerization on the monomers by a distillation precipitation method. The preparation method of the composite microspheres, provided by the invention, can be widely used for the biological medical, medical immunology and cosmetic manufacturing fields, in particular the tertiary oil recovery field, and can be used for profile control and oil flooding of low-permeability reservoirs. Polymer microspheres are prepared by using the distillation precipitation method, an improvement is made on the basis of the precipitation method and stirring is replaced with distillation; and the preparation method comprises the following steps of: in a distilled state, copolymerizing a mixture of one or more of the acrylamide as well as the acrylic acids and the derivatives thereof in a reaction container in the presence of an oil-soluble initiator; after all solvents are distilled, dispersing and washing obtained solid polymer microspheres by ethanol; and centrifuging, drying and grinding the solid polymer microspheres so as to obtain dry microspheres. The preparation method of the composite microspheres, provided by the invention, has the advantages of simple process and convenience in implementation.

The invention discloses a preparation method of In2O3 particles/In2O3 fiber composite material as well as the obtained product. The preparation method comprises the following steps: mixing cane sugar,p-phenylenediamine and dimethylformamide, adding ethanol, soluble indium salt and polyvinylpyrrolidone into the obtained mixture, and stirring until transparency to obtain a precursor spinning solution; and performing an electrostatic spinning method on the precursor spinning solution to obtain precursor fiber and performing heat treatment to obtain the final product. A novel precursor spinning solution system is designed, and a cubic ferromanganese ore type In2O3 particle/In2O3 fiber composite material with adjustable size and special appearance is prepared by the electrostatic spinning method. The raw materials are low in price, the synthesis process is simple and convenient, the reaction system is stable, the product is high in appearance repeatability, high in yield and easy in large-scale production, and the obtained product has large application potential in the field of a gas-sensitive material.

The invention belongs to the field of carbon nano tube preparation technologies, and particularly relates to a conversion method for converting a single-walled carbon nano tube into a double-walled carbon nano tube. The invention provides a conversion method for converting a single-walled carbon nano tube into a double-walled carbon nano tube. The conversion method comprises the following steps: carrying out a heat treatment: under vacuum or in a protective atmosphere, heating single-walled carbon nano tubes, and cooling the single-walled carbon nano tubes to the room temperature to obtain double-walled carbon nano tubes; wherein the average diameter of the single-walled carbon nano tubes is 1.1 to 1.7 nm. The detection result shows that the prepared double-walled carbon nano tube is narrow in diameter distribution; and meanwhile, the prepared double-walled carbon nano tube has higher yield, stability and purity. The technical defects of low yield and wide diameter distribution range of a conversion method for producing double-walled carbon nano tubes are overcome.

The present invention relates to a method for synthesizing transition metal oxide/silicon dioxide nano composite powder catalyst. Said invention adopts precursor hydrothermal method to make synthesis, and said catalyst can be used for preparing carbon nano tube, and said method includes the following steps: placing the catalyst into the catalytic bed quartz tube, heating to 500-600 deg.C under the condition of inert gas atmosphere, introducing hydrogen gas and reducing for 0.4-1.5 hr, when the temp. is reached to 630-780 deg.C, introducing acetylene and hydrogen gas whose volume ratio is 9:1-1:1 in the flowing rate of 40-200 ml/min to make it prduce cracking reaction to synthesize carbon nano tube, its reaction time is 0.5-1.0 hr.

The invention relates to a preparing method for a nanowire iron phthalocyanine/carbon nanofiber heterojunction composite material, and belongs to the technical field of composite materials. The preparing method includes iron-carbon nanofiber preparation and composite material preparation, composite material preparation includes the following steps that iron-containing carbon nanofibers, 4-nitrophthalonitrile and ammonium molybdate are poured into a reaction kettle together, ethanediol is added into the reaction kettle, the reaction kettle is sealed, placed in a drying oven and heated to be treated for 7-9 h, the reaction kettle is taken out and naturally cooled to room temperature, and a reaction product at the bottom of the kettle is taken out, washed, placed in a vacuum drying box to be dried for 4-6 h to obtain the composite material. The preparing method is simple in process, efficient, easy to operate, low in price and environmentally friendly and achieves large-scale production easily.