228results about How to "Avoid uneven dispersion" patented technology

The invention belongs to the field of macromolecule inorganic chemistry, and in particular relates to a method for preparing a graphene toughened silicon carbide ceramic composite material. Specifically, the method comprises the following steps: by taking graphite oxide as a carbon source, wrapping the surface of reduced graphene oxide with a layer of SiO2 granules by using a hydrothermal method so as to form a good interface layer between graphene and SiC, uniformly dispersing, and implementing carbon thermal reduction reaction at the interface of graphene and SiO2 in the high-temperature sintering process so as to growth silicon carbide crystal whisker and granules in situ, thereby improving the interface strength and the oxidation resistance, achieving an interface intensification function, improving crack expansion resistance and further improving the fracture toughness of ceramic. The method aims at the defects that graphene is poor in dispersity and high-temperature oxidation resistance in a conventional graphene/silicon carbide composite material, in-situ growth, crack self-healing and toughness mechanisms are applied to a preparation technique of a graphene/silicon carbide material, and thus graphene toughened silicon carbide ceramic with excellent mechanical properties and interface binding properties can be prepared.

The invention discloses a graphene-modified natural latex polymer and a modification method thereof. The modification method comprises modifying graphene through a coupling agent, uniformly dispersing the modified functionalized graphene in natural rubber to obtain the graphene-modified natural latex polymer and the modification method solves the problem of nonuniform dispersion of graphene in natural rubber. The graphene-modified natural latex polymer improves mechanical properties by 20-200%, improves barrier properties and blocks various viruses. The modification method of the graphene-modified natural latex polymer utilizes easily available raw materials and easily realizes large scale production. The invention also discloses the graphene-modified natural latex polymer prepared through the modification method.

The invention discloses a method for preparing a silicon carbide ceramic impeller through gel casting and pressureless sintering, and provides a preparation method of a pressureless sintered silicon carbide ceramic impeller with a complex and accurate shape characteristic and an external diameter size capable of reaching over 160 mm. A silicon carbide solid-phase sintering formula system of a boron-containing sintering auxiliary agent and a gel casting and pressureless sintering process are adopted; and the method comprises eight steps of: preparing ceramic slurry; performing injection molding; demolding; drying; machining; degumming; performing pressureless sintering; and machining. According to the method, the technical problems of non-uniform mixing of large-scale ceramic slurry in gel casting, dryness, crack and deformation in a pressureless sintering process and the like are solved, and finally, preparation of the pressureless sintered silicon carbide ceramic impeller is realized. The impeller has good performance such as corrosion resistance, wear resistance, high temperature resistance and the like, and can be widely applied to a centrifugal pump for corrosive liquid conveying of various industries.

The invention relates to silvering powder conductive adhesive for LED packaging and a production method thereof. The silvering powder conductive adhesive for LED packaging comprises, in weight percentage, 75-90% of silvering powder, 4-12% of epoxy resin, 3-10% of epoxy thinner, and 3-7% of additive. The production method includes: firstly, mixing the epoxy resin and the epoxy thinner at room temperature for 3-30 minutes; secondly, adding the additive in the mixture obtained in the step 1, and mixing at the room temperature for 3-30 minutes; thirdly, adding the slivering powder in the mixture obtained in the step 2, and vacuum-mixing at the room temperature to obtain the silvering powder conductive adhesive. The silvering powder conductive adhesive is simple in preparation and low in cost, and has fine and stable electric conductivity and thermal conductivity.

The invention provides a polymer/graphene aerogel composite foam material which is prepared from graphene aerogel and a thermoplastic polymer, wherein the graphene aerogel serves as a framework, the thermoplastic polymer is attached to the three-dimensional net structures of the graphene aerogel, and foam holes with closed pore structures are formed in the thermoplastic polymer. The composite foammaterial has mutually communicated three-dimensional net structures, and the content of the graphene aerogel in the composite foam material is 0.5%-10%. The invention also provides a preparation method of the composite foam material. The invention provides a new idea for solving the problem of agglomeration of graphene in polymer matrix materials.

The invention discloses a composite hybrid organic silicon LED (Light Emitting Diode) packaging material, preparation method and applications thereof. The composite hybrid organic silicon LED packaging material is prepared by uniformly mixing 10-100 parts of silicon dioxide phenyl organic silicon composite hybrid, 0-48 parts of vinyl polysiloxane, 0.00001-0.0002 part of catalyst A and 1.6-32 parts of hydrogen-containing polysiloxane, and reacting for 1-8 hours under the vacuum condition of 80-110 DEG C. According to the composite hybrid organic silicon LED packaging material provided by the invention, not only is the preparation method simple, the raw materials are environment-friendly and easily available, and the packaging material has the advantages of high refractive index, high transmissivity, and high mechanical strength to meet the requirements of LED packaging. The prepared composite hybrid organic silicon LED packaging material is mainly used for high-power LED and LED with white light.

The invention relates to a high-weather-resistance acrylate resin composition and a preparation method thereof. The raw materials of the high-weather-resistance acrylate resin composition comprise the following components in part by weight: 10 to 30 parts of acrylate rubber powder 1, 10 to 30 parts of acrylate rubber powder 2, 30 to 60 parts of SAN resin 1, 5 to 20 parts of heat-resistant modifier, 5 to 15 parts of weather-resistant master batch, 0.3 to 3 parts of lubricant and 0.05 to 0.5 part of antioxidant. The preparation method comprises the following steps of: stirring the raw materials except the weather-resistant master batch to obtain a mixture; adding the mixture from a main feed inlet of a double-screw extruder, and adding the weather-resistant master batch from a side feed inlet; and extruding and pelleting the raw materials by the double-screw extruder to obtain a sample. The high-weather-resistance acrylate resin composition prepared by the method has higher heat resistance, low-temperature impact resistance, weather resistance, excellent size stability and processing property, and is particularly suitable for automobile exterior trim parts, such as radiator grilles, rear-view mirrors, license plates, central pillar plates, outdoor triangular blocks and the like, with high requirements on weather resistance, heat resistance and low-temperature impact resistance.

The invention relates to polyphenylene sulfide (PPS)/nano-calcium carbonate mixture and a preparation method for the fiber thereof. The method includes the steps of mixing polyester slices, nano-calcium carbonate particulates, reactive monomer and other additives in a high speed mixer while rising the temperature to approximately 205 DEG C so as to enable the polyphenylene sulfide slices to intenerate and the nano-calcium carbonate and other additives to be evenly adhibitted onto the polyphenylene sulfide slices, without heavy conglutination between the particles on the polyphenylene sulfide slices. The polyphenylene sulfide (PPS)/nano-calcium carbonate mixture prepared through the method has excellent processability and can be made into textile fiber, thin film or reinforcement plastics by means of melt blown or melt spinning process. The invention can greatly reduce the production cost and bring good economic benefits. The polyphenylene sulfide(PPS)/ nano-calcium carbonate mixture has good thermal stability, flame retardancy, chemical corrosion resistance and good mechanical property and spinning property; therefore the polyphenylene sulfide(PPS)/nano-calcium carbonate mixture is widely applicable to the industrial sectors like chemical industry, light industry and mechanical industry, and is particularly good for accelerating the popularization and application of high-temperature house-bag dust removal. The preparation method has the advantages of simple process, easy control, low cost, short production period, environment friendly and particularly being applicable to the industrial production.

The invention discloses high belite sulphoaluminate cement based disturbance-resistance concrete for rush repair and a preparation method of the high belite sulphoaluminate cement based disturbance-resistance concrete and belongs to the field of building materials. The high belite sulphoaluminate cement based disturbance-resistance concrete for rush repair is prepared from the following raw materials in parts by weight: 100 parts of high belite sulphoaluminate cement, 1-100 parts of mineral admixture, 120-200 parts of fine aggregate, 200-300 parts of coarse aggregate, 0.1-1.0 part of polymer,1.0-2.0 parts of fiber. The water cement ratio is 0.28 to0.45. The polymer is a water reducer and a thickener; and the fibers are PP, PVA or steel fibers. For the high belite sulphoaluminate cement based disturbance-resistance concrete for rush repair, by adopting the high belite sulphoaluminate cement as a main cementitious material of disturbance-resistance concrete, the characteristics of quicksetting, early strength and high later strength of the high belite sulphoaluminate cement are exerted; and by optimizing a proportion of the water reducer and crack-resistance fibers, the disadvantages of low early strength, long disturbed period, easiness in cracking under disturbance and the like of ordinary concrete are solved, the disturbance resistance performance and the crack resistance performance of the concrete are improved, the influence of vehicle disturbance on the performance of the concrete is remarkably reduced, the requirement for demi traffic and demi closing of engineeringnowadays is met, the construction efficiency is improved, and the quality of the engineering is ensured.

The invention relates to a method for preparing an electromagnetic shielding wooden plate. The method comprises the following steps: (1) preparing a base material according to the mass ratio of 1:1-1:2 of a wood powder and a graphite powder, mixing in a mixer, adding magnetic particles accounting for 0.5%-1% of the mass of the graphite powder, agitating and heating to 100-120 DEG C; (2) adding a finishing agent accounting for 0.5%-1.4% of the amount of the base material, and a resin which is 1.67-2.5 times of the amount of the base material in the mixer, mixing for 8-15 minutes, discharging the material and feeding the material to a cool mixer, mixing to the normal temperature, and granulating; and (3) cutting, packaging and measuring the shielding factors after the granulated materials enter a plate extrusion device for formation. The invention has the advantages of low cost, wide resource, low density, high electromagnetic shielding capacity in an ultra wideband range, and higher electromagnetic wave absorption capacity.

The invention relates to a solid particle foam inhibitor and a method for preparing the same. The ingredients of the foam inhibitor consist of 50-80% of organic carrier, 10-18% of main defoaming materials, 0.5-4% of emulsifying agent, 1-10% of structural agent and 3-25% of deionized water. The method for preparing the foam inhibitor comprises the following steps of: sufficiently mixing the main defoaming materials with the emulsifying agent; adsorbing the main defoaming materials and the emulsifying agent on the carrier; and adding the structural agent and forming particles with good liquidity through working procedures of granulating and drying. The prepared solid particle foam inhibitor has excellent applications in industrial processes, such as washing, sewage treatment and textile printing and dyeing.

The invention discloses a photodiffusion composite. The photodiffusion composite is characterized by comprising the following raw materials by weight: 87.5 to 96% of polycarbonate, 4 to 12% of organic photodiffusion master batch and 0 to 0.5% of inorganic photodiffusion master batch, wherein the organic photodiffusion master batch comprises, by weight, 90% of polycarbonate and 10% of a photodiffusing agent 1, and the inorganic photodiffusion master batch comprises, by weight, 90% of polycarbonate and 10% of a photodiffusing agent 2. The invention also discloses a preparation method for the photodiffusion composite. According to the invention, the method of addition of the master batch is employed, so the problem of nonuniform dispersion of the photodiffusing agents is overcome, and the photodiffusion composite has high light transmittance and haze; and addition of a small amount of the inorganic photodiffusion master batch enables the haze of the composite to be improved.

The invention discloses a method for preparing a graphene reinforced magnesium-based composite material based on powder thixoforming. The method aims to solve the following problems that: firstly, dispersion of graphene in the graphene reinforced magnesium-based composite material prepared by a composite casting process is poor; and secondly, the graphene reinforced magnesium-based composite material prepared by a powder metallurgic method is not high in compactness, and has difficulty of forming a large-dimension product with a complex shape. The method comprises the following steps of: adopting an ultrasonic and mechanical stirring process for mixing magnesium alloy powder and a graphene nanosheet in alcohol, filtering and drying, pressing mixed powder into blank, heating the blank at asemi-solid-state temperature of the magnesium alloy to obtain semi-solid-state ingot; and performing thixoforming on the semi-solid-state ingot to obtain the graphene reinforced magnesium-based composite material.

The invention provides a homogenizing method of a lithium ion battery positive electrode slurry. The method comprises the following steps of: S1, feeding a positive active substance, conductive agentdry powder and binder dry powder into a double-planet stirrer one by one according to a ratio by using an automatic feeding system, and carrying out powder premixing to obtain a dry powder mixture; S2, dividing a solvent into two parts, adding a conductive agent slurry and one part of a solvent into the dry powder mixture prepared in S1 in proportion, and conducting first mixing to obtain a semi-finished product slurry; S3, starting a high-speed mixer, inputting the semi-finished product slurry obtained in S2 and another part of solvent into the high-speed mixer for high-speed mixing and dispersing, and pumping the mixed slurry into a circulation tank A; S4, inputting the slurry in the circulation tank A into the high-speed mixer again for high-speed mixing and dispersing, and pumping themixed slurry into a circulation tank B. The double-planet stirrer and the high-speed mixer are used at the same time, the slurry dispersion uniformity can be improved, and the slurry granularity consistency is better.

The invention relates to the technical field of elastic paint and discloses yellowing-resistant elastic paint and its preparation method, use method and application. The yellowing-resistant elastic paint comprises a component A and a component B. The component A comprises, by weight, 18-53% of film-forming resin, 1-2% of an eco-friendly dryer, 0.1-0.5% of a leveling agent, 40-70% of an organic solvent, 8-23% of matting powder and 0.1-0.5% of a UV absorber. The component B is a curing agent. A weight ratio of the component A to the component B is 100: 10-15. The eco-friendly dryer is organic zinc. The yellowing-resistant elastic paint has the characteristics of yellowing resistance, high activity of drying, good stability and environmental friendliness.

The invention provides carbon fiber paper with a conductive network enhanced by carbon black and a preparation method thereof, and the method comprises the following steps: step 1, uniformly dispersing carbon fibers, aramid fibrid and carbon black in a polyoxyethylene aqueous solution according to a ratio of (40-80): (10-50): 10 to obtain a mixed slurry; step 2, molding the mixed pulp to obtain a wet paper web of the carbon fiber paper, and sequentially squeezing and drying the wet paper web of the carbon fiber paper to obtain raw paper of the carbon fiber paper; and step 3, dipping raw paper of the carbon fiber paper in the phenolic resin solution, airing, and hot-pressing at 150-160 DEG C to obtain the carbon fiber paper with the conductive network enhanced by the carbon black. The carbon fiber electric heating paper with high heating rate and good temperature resistance is prepared by introducing aramid fibrid as dispersion forming fiber and carbon black as a three-dimensional network structure bridge.

The invention discloses a graphene-based foamed lightweight refractory thermal insulating decoration board which comprises a matrix foamed lightweight refractory thermal insulating material layer anda decorative surface layer, wherein after sprayed to the surface of the matrix foamed lightweight refractory thermal insulating material layer, the decorative surface layer and the matrix foamed lightweight refractory thermal insulating material layer are adhered together by virtue of one-step sinter molding; the matrix foamed lightweight refractory thermal insulating material layer comprises thefollowing raw materials in percentage by weight: graphene, inorganic high-temperature-resistant fibers, non-metallic tailings, expanded vermiculite, expanded perlite, zirconia, a high-temperature cosolvent, a water repellent, an inorganic high-temperature-resistant adhesive and a flame retardant; and the decorative surface layer comprises the following raw materials in percentage by weight: graphene, feldspar, quartz, alumina, wollastonite, calcium carbonate and pigments. According to the prepared finished product in the invention, the materials are uniformly dispersed; and moreover, the prepared board has the advantages of being lightweight, high in strength, fire-resistant, flame-retardant, resistant to water seepage, difficult to age, excellent in mechanical property, green, saving in energy and environmentally friendly and has wide market popularization value.

The invention discloses a novel nanometer titanium dioxide self-cleaning fluorine-carbon aluminum single sheet as well as a low-temperature preparation method and application thereof. The surface of the fluorine-carbon aluminum single sheet is coated with a self-cleaning nanometer titanium dioxide film or a nanometer titanium dioxide and silicon dioxide composite film; the film is uniformly distributed on the surface of the fluorine-carbon aluminum single sheet, and thickness of the film is 1-3 micrometers; and after being irradiated by ultraviolet light, the nanometer titanium dioxide film has super-hydrophilic property and photocatalytic property, thus, the self-cleaning effect is realized. The novel nanometer titanium dioxide self-cleaning fluorine-carbon aluminum single sheet related in the invention has the following advantages: (1) the thickness of the titanium dioxide film is uniform, nanometer titanium dioxide crystal particles are uniformly distributed, and the titanium dioxide film has super-hydrophilic property and a better self-cleaning function; (2) the film has photocatalytic property, so that residual organic pollutants on the surface of the film can be decomposed, and the self-cleaning effect is further improved; and (3) the original performances, such as weatherproof performance, chemical corrosion resistance and the like, of the fluorine-carbon aluminum single sheet are retained.

The invention belongs to the technical field of functional materials and in particular relates to a plant nanocellulose-based flexible electromagnetic shielding film as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) preparing a nano-silver-graphene oxide-nanocellulose dispersion solution which is uniformly dispersed, wherein the total mass of nano-silver is 1 percent to 10 percent of the total mass of graphene oxide and the total mass of the graphene oxide is 5 percent to 20 percent of the total mass of nanocellulose; (2) after carrying out ultrasonic de-foaming on the dispersion solution, filtering in vacuum to form a film; drying the film to obtain a nano-silver-graphene oxide-nanocellulose composite film; (3) reducing thenano-silver-graphene oxide-nanocellulose composite film by utilizing vitamin C to obtain a nano-silver-graphene-nanocellulose composite film. The preparation method provided by the invention has the advantages of simple preparation technology and easiness for operation and production; the prepared composite film has antibacterial and electromagnetic shielding effects and has a good application prospect.

The invention provides a modification method of negative-ion mineral powder with reaction activity. The method specifically comprises steps as follows: negative-ion mineral powder is subjected to purification, activation, grinding and heat treatment for use; 100 parts of the negative-ion mineral powder by weight are added to 100-500 parts of an acetone solvent, the mixture is stirred at the speed of 30-100 r/min for 30-60 min, then 3-10 parts of isocyanate are added at the flow speed of 1-5 g/min, the mixture reacts at the temperature of 40-80 DEG C for 3-5 h, the acetone solvent is recovered through reduced-pressure distillation, and the isocyanate-modified negative-ion mineral powder with the reaction activity is obtained. The modified negative-ion mineral powder can participate in formation of molecular chains of polymers, has the reaction activity of the isocyanate and can participate in synthetic reactions of the polymers, so that the negative-ion mineral powder is organically combined in the molecular chains of the polymers, and the phenomenon that negative ions are not dispersed uniformly due to conventional adding methods is eliminated.