1051results about How to "Narrow distribution" patented technology

A catalyst and a process are provided for oligomerizing ethylene. A heterogeneous catalyst system comprises: (1) a chelating ligand, preferably 2-diphenyl phosphino benzoic acid (DPPBA); (2) a nickel precursor, preferably nickel chloride hexahydrate (NiCl2.6H2O); (3) a catalyst activator, preferably sodium tetraphenylborate (NaBPh4); and (4) silica. A 1:1:1 molar ratio of Ni:DPPBA:BPh4 catalyst components are fixed on a silica support using low-temperature fixation. The catalyst components are dispersed in a diluent, preferably ethanol, and silica is added. The ethanol is evaporated using freeze-drying equipment to form a silica-supported catalyst system. The silica-supported catalyst is slurried in ethanol in a reactor, and ethylene is added. The reactor pressure and temperature are maintained at about 725 psig and 100° C., respectively, for about two hours. The oligomer product formed has a narrower weight percent distribution, typically having about 96 weight percent C4's to C10's, compared to product formed using a homogeneous catalyst system.

A solder ball having a diameter of 1.2 mm or less, a dispersion of a diameter distribution of 5% or less and sphericity of 0.95 or more, an area ratio of the maximum dendrite being 80% or less of a cross section including a center of the solder ball, comprises a first additional element of 0.5-8 mass% of Ag and/or 0.1-3 mass % of Cu, and 0.006-10 mass %, in total, of at least one second additional element selected from the group consisting of Bi, Ge, Ni, P, Mn, Au, Pd, Pt, S, In and Sb, the balance being substantially Sn. The solder ball is produced by a uniform droplet-spraying method comprising the steps of vibrating a melt of a solder alloy in a crucible under pressure to force the melt to drop through orifices of the crucible; permitting the melt dropping through the orifices to become spherical droplets in a non-oxidizing gas atmosphere; and rapidly solidifying them.

In a nonvolatile floating-gate semiconductor memory device, a word line voltage supply circuit is configured to be able to apply gate voltages to the same memory cells such that the gate voltage applied at and after the second time is different from the gate voltage applied at the first time. At least one of the word line voltage supply circuit and the bit line voltage supply circuit is set to be able to apply a voltage to the same memory cells for a longer application period at the first time than at and after the second time. With this configuration, the threshold voltage distribution of the memory cells is controlled to be narrow.

A porous monocomponent nonwoven web contains a bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition. There are at least five times as many microfibers as larger size fibers, and a histogram of the mass fraction of fibers vs. fiber size exhibits a larger size fiber mode greater than 10 μm. The web may be made by flowing fiber-forming material through a die cavity having larger size orifices and at least five times as many smaller size orifices to form filaments, attenuating the filaments into fibers and collecting the attenuated fibers to form the nonwoven web. The web is especially well suited to the manufacture of self-supporting three dimensional articles such as molded cup-shaped respirators and pleated air filters.

The invention belongs to the technical field of recovery of lithium-ion batteries and particularly relates to a method for recovering a waste/used lithium iron phosphate positive-pole material by an acid leaching method. The method provided by the invention comprises the following steps: (a) carrying out acid leaching: adding acid into the lithium iron phosphate positive-pole material for acid leaching so as to obtain a suspension, and carrying out filtration, so as to obtain filtrate; (b) carrying out oxidation: adjusting the pH value of the filtrate obtained in the step (a) to be smaller than 1, and adding an oxidant into the filtrate to oxidate ferrous ions in the filtrate into ferric ions, so as to obtain a mixed solution; (c) carrying out separation: adjusting the pH value of the mixed solution obtained in the step (b) to be 1.5 to 4, carrying out a reaction for 1 to 3 hours at the temperature of 60 DEG C to 95 DEG C so as to produce ferric phosphate precipitates, and carrying out filtrating and washing, thereby obtaining lithium-containing filtrate and ferric phosphate. The method provided by the invention is simple in process, continuous in cycle, low in cost and easy to industrialize and is environmentally friendly; the recovery rate of Li, Fe and P reaches 95% or more, subsequent prepared FePO4 is low in impurity content, the particle size is 1 to 6 microns, is uniform and is narrow in distribution, and the morphology is controllable, so that the FePO4 is battery-grade ferric phosphate.

The invention provides a preparation method of a graphene-silver nano particle composite material. A specific preparation process comprises the following steps of: preparing solution of silver ammonia at certain concentration from the solution of silver nitrate and aqueous solution of dilute ammonia, adding the prepared solution of silver-ammonia into the solution of graphene oxide which is subjected to ultrasonic processing, preheating the solution at a certain temperature for a certain time; adding an appropriate amount of glucose into the mixed solution of graphene oxide and silver ammonia, and reacting the mixed solution at the set temperature for a certain time with stirring; performing suction-filtration on a reaction product by using deionized water for many times, and then drying the product to obtain the graphene-silver nano particle composite material. The method is simple, convenient, easy, environment-friendly and efficient; and silver nano particles in the prepared composite material are distributed narrowly, have a uniform particle size (about 25 nm), can be better inserted into graphene slices and can effectively prevent aggregation of the graphene.

The invention relates to a device and a method for manufacturing an airflow melting electrostatic spinning nano-fiber non-woven fabric. The device for manufacturing the airflow melting electrostatic spinning nano-fiber non-woven fabric comprises a stock hoper, a screw extruder, a filter, a metering pump, a material path, a melt-blown die head, a hot-air pipeline, an air compressor, a heating device, a high voltage electrostatic generator and a receiving device. The material path is made of high thermal conductivity insulating ceramics. The method for manufacturing the nano-fiber non-woven fabric adopts the device disclosed by the invention and comprises the following processing steps: (1) preparing a polymer melt; (2) jetting nano-fibers by using airflow static electricity; and (3) moulding the non-woven fabric. The method for manufacturing the nano-fiber non-woven fabric of the invention adopts airflow-melting electrostatic spinning technology, avoids a problem of pollution of electrostatic spinning solvent, and is novel environment-friendly non-woven fabric manufacturing technology. In the manufacturing method, high voltage electrostatic is directly acted on the melt-blown die head; the melt has high and uniform charge; and simultaneously by utilizing drafting of the airflow, the prepared nano-fiber has the advantages of thin diameter and narrow distribution. The device can meet production requirements by improving the conventional melt-blown manufacturing device, and has low implementation cost and easy industrialization promotion.

A metal nanoparticle colloid solution, metal-polymer nanocomposites, and methods for preparing the same are provided. The metal nanoparticle colloid solution and the metal-polymer nanocomposites can be prepared with a variety of polymeric stabilizers and have uniform particle diameter and shape. The metal nanoparticle colloid solution and the metal-polymer nanocomposites have wide applications, for example, as an antibacterial agent, a sterilizer, a conductive adhesiv, conductive ink or an electromagnetic wave shielder for an image display.

The present invention is preparation process of plate microporous composite polyvinylidene fluoride film. The preparation process includes: mounting the support layer on composite film scraping machine and regulating the cloth speed; regulating the interval between the support layer and the scraper with plug gage; feeding filming liquid into the film scraping machine and coating the liquid to the support layer to form film, running the film in the air for some time, soaking the film in solidifying bath to form the composite film of polyvinylidene fluoride and the support layer. The composite film features large pore size, high strength and high water flux. The composite film is measured to have pore size of 0.1-1.5 micron, pure water flux of 400-2100 L/hr.sq m (at 0.1MPa), thickness of 150-220 microns, radial tensile strength of 35.2 MPa, radial elongation at breaking of 51.92 %, transverse tensile strength of 18.2 MPan and transverse elongation at breaking of 68.7 %.

The invention relates to cosmetic active ingredient-containing lipidosome as well as a preparation method and application thereof. The cosmetic active ingredient-containing lipidosome is small and uniform in particle size, so that the wrapped active ingredients can permeate the cuticles to the deep layer of skin so as to effectively realize deep skin care. Moreover, due to the small particle size, the collision and sedimentation probability of the finished lipidosome product is decreased and the stability of the lipidosome cosmetic is improved. The cosmetic active ingredient-containing lipidosome is prepared by a host-guest chemical method, so that the lipoid molecules and the active ingredient molecules are uniformly mixed on the molecular level, so that the gathering inactivation phenomenon of the active ingredients is avoided; the preparation condition is mild, so that the active ingredients are prevented from damage.

A method for producing a colloid of metallic nanoparticles including the steps of: providing metal ions in solution; providing a stabilizing agent; and reducing said metal ions in the presence of said stabilizing agent, so that metallic nanoparticles are formed with a surrounding layer of said stabilizing agent, wherein the reduction step is carried out at a temperature of not less than 20° C. and not more than 150° C. The metallic nanoparticles are formed of a mixture of transition metal and noble metal, such as Ni—Pd. The resultant nanoparticles have a high stability in terms of size and chemical degradation and so can be stored for long periods. They are therefore particularly suited for forming patterned nanoparticle arrays on a substrate by nanocontact printing for the subsequent formation of a corresponding array of carbon nanotubes or nanofibers via plasma enhanced CVD.

The invention relates to a preparation method for a nano-sliver/cellulose nanocrystalline composite particle. The preparation method comprises the following steps of: (1) adding a cellulose raw material into an acid-mixed solution and reacting at the temperature of 50-90DEG C for 1-20 hours; after the reaction is ended, washing a reaction product with deionized water to neutral and obtaining aldehyde cellulose nanocrystalline; and (2) adding the aldehyde cellulose nanocrystalline into a silver nitrate solution; reacting at the temperature of 60-105DEG C for 10-60 minutes; and after naturally cooling, diluting a reaction product with the deionized water, centrifuging and then carrying out free drying or vacuum drying to obtain a nano-silver/CNC (Cellulose Nanocrystalline) composite material. The preparation method disclosed by the invention is simple and convenient in process, easy in operation and environment friendly and can be used for shortening the preparation period; the prepared CNC/nano-silver has the advantages of small size, easy adjustment, large specific area, firmness in combination of the CNC and the nano-silver, durable antibacterial effect, antibacterial and enhancing functions and broad application prospect.

The invention relates to a preparation method of echinoid titanium dioxide microspheres in single/double layer cavity structure, belonging to the field of nano composite materials. The method comprises the following steps: (1) preparing monodisperse silicon dioxide microspheres with uniform particle size; (2) by using silicon dioxide as a template, coating a titanium dioxide layer on the surface of the silicon dioxide microspheres by using a sol-gel method to obtain core-shell type silicon dioxide/titanium dioxide composite microspheres; (3) regulating the concentration of sodium hydroxide solution, the hydrothermal reaction time and other conditions, and preparing echinoid titanium-base microspheres in the single/double layer cavity structure in a controllable way; and (4) treating the echinoid titanium-base microspheres in the single/double layer cavity structure with hydrochloric acid with a certain concentration, and calcining at high temperature to obtain anatase-type echinoid titanium dioxide microspheres in the single/double layer cavity structure. The material prepared by the method has the high-activity pure-phase titanium dioxide crystal structure, and has the advantages of large specific area, complete appearance and high yield; the technical process is controllable and easy to operate; and the invention also has the advantages of low preparation cost, no pollution and low energy consumption.

The invention relates to a method for preparing hollow cavity type ZSM-5 modified zeolite molecular sieve, and aims to solve the problems that the microcellular structure diffusion admittance is narrow, the modified zeolite molecular sieve has lower relative degree of crystallinity, and the adjustable range of apertures inside molecular sieve is small, thereby facilitating macromolecule reaction limited by diffusion. The invention adopts at least one 0.1-8.5 mol/L acid solution of hydrochloric acid, nitric acid, sulphuric acid or acetic acid to treat ZSM-5 molecular sieve raw powder with the silica alumina ratio SiO2/Al2O3 being 20-1000 and the particle size being 0.4-10 Mum for 1-8 h; then at least one 0.1-5.0 mol/L aqueous alkali of sodium hydroxide, magnesium hydrate, potassium hydroxide, sodium carbonate or sodium bicarbonate is used for treatment for 1-48 h at 20-90 DEG C; and at least one 0.1-8.5 mol/L acid solution of hydrochloric acid, nitric acid, sulphuric acid or acetic acid is used for treatment for 1-48 h at 20-90 DEG C to obtain the modified ZSM-5 molecular sieve. The problems are well solved, and the invention can be used in industrial production of macromolecule catalysis and transformation catalysts.

The invention relates to a method for preparing a silicone-modified acrylate adhesive, which comprises the following: (1) a step of the pre-polymerization of a modified monomer, in which the modified monomer, a modified monomer catalyst, an emulsifying agent and deionized water are pre-polymerized to obtain a silicone pre-polymerization emulsion; (2) a step of emulsification, in which the silicone pre-polymerization emulsion and a basic monomer are emulsified to obtain an intermediate pre-emulsion; and (3) a step of the polymerization of acrylic ester, in which the intermediate pre-emulsion is polymerized with a basic monomer catalyst and the deionized water to obtain a finished product. The method adopts a fractional step method to emulsify according to the hydrophilicity of various monomers. During the emulsification step by step, a polymeric monomer with stronger hydrophobicity which is added first can be effectively and steadily dispersed under the condition of relatively higher concentration of the emulsifying agent, which strengths the stability of a monomer pre-emulsion. The grain diameter of the prepared adhesive emulsion is smaller and has narrower distribution, the emulsion system is also more stable, and various application performances are superior to those of adhesive products prepared by the prior method.

The invention discloses a preparation method of a nano-silver alginate fiber. The preparation method comprises the following steps of: preparing an alginic acid silver complex which is a precursor of nano-silver by using algal polysaccharides and soluble silver salts, and then preparing a sodium alginate based nano-silver colloid system through a chemical reduction method; then adding fiber-grade sodium alginate into the sodium alginate based nano-silver colloid system to obtain a nano-silver algae spinning solution; and finally, obtaining a nano-silver algae primary fiber through wet spinning, and carrying out stretching, sizing, drying and oiling treatments to obtain the nano-silver alginate fiber. The prepared nano-silver alginate fiber integrates the excellent performances of the nano-silver and the alginate fiber, so that the novel fiber has excellent flame retardance, biocompatibility, moisture absorption permeability and the like, also has excellent antimicrobial performance, antistatic performance and irradiation resistance and can be widely used in medical treatment, the fire-fighting field, the military field, the aerospace field, the health textile field and the like.