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.

Disclosed herein is a method for preparing ultrathin silver nanowires. It may comprise (a) dissolving a silver salt (Ag salt) and a capping agent in a reducing solvent to give a mixture solution; (b) adding a halide compound to the mixture solution to yield a silver seed; (c) heating the mixture solution and then allowing the heated mixture solution to grow ultrathin silver nanowires from the silver seed under a pressure in an inert gas atmosphere; and (d) cooling the mixture solution in which the ultrathin silver nanowires have grown, followed by purification and separation to obtain the ultrathin silver nanowires. The silver nanowires are restrained from growing in thickness under a certain pressure, so that they are 30 nm or less in thickness and have a narrow diameter distribution, which leads to an improvement in aspect ratio.

The invention relates to a sustained-release microsphere of antipsychotic drug risperidone and the preparation method thereof.

The invention discloses a catalyst for a zinc oxide nanowire and application of the catalyst in growth of the zinc oxide nanowire. The catalyst for the zinc oxide nanowire is an Au / M multilayer film or an Au-M alloy film formed by metal Au and metal M with a mass ratio of 0.2 to 5:1, wherein M is a metal, the eutectic point of which and Zn is below 500 DEG C, preferably, M is a metal, the eutectic point of which and Zn is below 300 DEG C. Compared with gold as a catalyst under similar conditions, the catalyst is used for the growth of the zinc oxide nanowire, and the higher growth rate of the zinc oxide nanowire can be obviously obtained, the density of arrays of the prepared zinc oxide nanowire is larger, the diameter and the length of the nanowire are more uniform, and the grown zinc oxide nanowire has higher crystalline quality.

The invention discloses a high-strength high-elasticity intravascular stent and a preparation method thereof and belongs to the field of chemical and ecological engineering. The high-strength high-elasticity intravascular stent has the advantages that a biocompatible polymer material is taken as a precursor; firstly, an electrostatic spinning method is adopted for preparing fibrous membranes with different mechanical properties; and on this basis, an electrospinning technology and a solution soaking and removing method are combined for preparing a high-strength, high-elasticity and high-porosity artificial intravascular stent, fibers used for forming the artificial intravascular stent are smooth in surface, uniform in morphology, narrow in fiber diameter distribution range, and excellent in vascular performance. The obtained artificial intravascular stent with high cell compatibility, strength, elasticity and porosity can be produced in a large scale and is expected to be applied to the actual clinical diagnosis.

A method for making the mesoporous material includes the following steps: dissolving a nanocrystal powder in an organic solvent, and achieving a solution A with concentration of 1-30 mg / ml; dissolving a surfactant in water, and achieving a solution B with an approximate concentration of 0.002-0.05 mol / ml; mixing the solution A and the solution B in a volume ratio of 1:(5-30), and achieving a mixture; stirring and emulsifying the mixture, until an emulsion C is achieved; removing the organic solvent from the emulsion C, and achieving a deposit; washing the deposit with deionized water, and achieving a colloid; and drying and calcining the colloid, and eventually achieving a mesoporous material. The mesoporous material has a large specific surface area, a high porosity, and a narrow diameter distribution.

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 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 a preparation method of a high-crystallinity double-walled carbon nano tube, belonging to the technical field of preparation processes of carbon nano tube materials. The preparation method is characterized in that the carbon nano tube is prepared by adopting an anodic carbon electrode bar containing an iron catalyst and realizing the arc discharge between a negative electrode and a positive electrode by using an arc discharging method under a discharging atmosphere of hydrogen or mixed gas of hydrogen and argon, and meanwhile, the double-walled carbon nano tube is purified under the high-temperature treatment of hydrogen and air so as to finally obtain the double-walled carbon nano tube with purity above 90 percent. The prepared double-walled carbon nano tube has the advantages of high crystallinity, narrow caliber distribution, small average diameter and high purity.

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 of the 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.

A process for preparing vapor-grown carbon fibers comprises adding 10-35% iron or cobalt oxide and 65-90% zirconia carrier composed of ferric nitrate or cobalt nitrate solution according to weight percent of a catalyzer into the zirconia carrier, and dipping, airing, calcination to obtain the catalyzer. The catalyzer is reduced in a hydric ambience, thereafter the catalyzer's temperature is lifted to a rature 1000-1160 DEG C and a carbon source is entered, an adding amount of the carbon source of a unit quality catalyzer is 0.005-0.040 ml / min, the vapor-grown carbon fibers are obtained by 20-60 minutes reaction. The invention has advantages that the preparing process is simple and easy to operate, the obtained vapor-grown carbon fibers are even, and having a narrow diameter distribution range.

The invention relates to a spherical revolving brush type batched electrostatic spinning device and a usage method thereof. The spherical revolving brush type batched electrostatic spinning device comprises a liquid supply system, a separating electric field control system, a spherical rotary spinning system and a nanofiber collecting system, wherein the liquid supply system comprises an air cylinder, a spinning solution storage bottle, an oil batch tank and a solution guiding tube, the spinning solution storage bottle is arranged in the oil batch tank, the spinning solution storage bottle and the solution guiding tube form a communicator structure through a solution brushing tank, the spinning solution storage bottle is connected with the air cylinder through an air tube, and a main valve and a pressure reducing valve are sequentially arranged at the position, close to the air cylinder, on the air tube. The separating electric field control system comprises a high-pressure generator, a metal round ring, a cylindrical seat and a support, wherein the support is arranged at the upper end of the spinning solution storage bottle, the cylindrical seat is arranged on the support, and the metal round ring is installed on the cylindrical seat in a sleeving mode to be connected with the high-pressure generator. Automatic supply of a high polymer solution and stable batched nanofiber preparation can be completed.