40results about How to "Prevent reaggregation" patented technology

The invention discloses high-toughness concrete and a preparation method thereof. The formula of the high-toughness concrete comprises 0.2-0.5kg/<m>3 of modified graphene, 150-175kg/<m>3 of water, 395-415kg/<m>3 of cement, 45-60kg/<m>3 of coal ash, 20-35kg/<m>3 of slag powder, 1000-1100 kg/<m>3 of broken stone, 600-700 kg/<m>3 of fine aggregate and 4.5-7 kg/<m>3 of a water reducing agent, wherein the modified graphene is water-soluble grapheme of which the surface has hydroxide radicals; the content of the hydroxide radicals is 0.005-0.012 percent. When the modified grapheme is used for preparing high-toughness concrete, first, the modified grapheme can be dissolved in water to form a graphene water solution; then, the graphene water solution and other concrete preparation materials are uniformly mixed, novel high-toughness concrete obtained after curing can show obvious strain hardening or deformation hardening characteristic under the action of direct tensile load or bending load, and can be applied to bridge floors of high-speed rail viaducts and long-span sea-crossing and river-crossing bridges, and various tunnel arches such as subways. The high-toughness concrete is high in technological content and has relatively good application prospect.

The invention discloses a high-density polyethylene/graphene/polyaniline composite material and a synthetic method thereof. According to the high-density polyethylene/graphene/polyaniline composite material, the surface of graphene is coated with polyaniline to form a polyaniline/graphene blend, and the polyaniline/graphene blend is dispersed in a high-density polyethylene substrate. As the polyaniline (PANI) coats the graphene (CB) to be blended with the high-density polyethylene (HDPE) substrate, the dispersity of the graphene is improved, the degree of crystallinity of the high-density polyethylene is reduced, therefore, the PTC intensity and the stability of the polyethylene/graphene/polyaniline composite material are improved.

The invention relates to the technical field of coating preparation, in particular to waterborne titanium white paste and a preparation method thereof. The waterborne titanium white paste comprises the following raw material components in parts by weight: 12-18 parts of deionized water, 2-6 parts of a humectant, 8-12 parts of a dispersing agent, 0.1-0.5 part of a defoaming agent, 70-76 parts of rutile type titanium dioxide, 0.3-1.0 part of an anti-settling agent, 0.1-0.2 parts of a bactericide and 0.1-0.3 part of a pH adjuster. The waterborne titanium white paste provided by the invention hasgood compatibility with a two-component polyurethane system, and the color paste itself is high in stability, suitable not only for the two-component polyurethane system, but also for an one-componentpolyurethane system, an acrylic acid system and other systems, low in VOC (volatile organic compounds) content, safe, environmentally-friendly, simple in preparation method, easy to operate, and suitable for large production operations.

The invention provides a method of preparing tungsten-doped superfine yttrium oxide compound powder by freeze drying. The method comprises the following steps: dissolving ammonium metatungstate and ayttrium nitrate hexahydrate in deionized water or distilled water, and carrying out ultrasonic treatment to disperse and dissolve the mixture to prepare a solution; pouring the solution into a surfacevessel or other containers large in surface areas, putting the surface vessel or other containers in a refrigerator, and pre-freezing the same at 40 DEG C below zero and 10 DEG C below zero; openingrefrigeration and a vacuum meter of a freeze drier in advance, and after the temperature of the freeze drier is reduced to the freezing temperature of 58 DEG C below zero and 20 DEG C below zero and is stabilized, putting the pre-frozen surface vessel in the freezer dryer, and opening a vacuum pump to maintain the vacuum degree and carry out freeze drying; putting the freeze-dried compound powderin a tubular furnace, and calculating the compound powder in a nitrogen or an argon air flow to obtain WO3-Y2O3 compound oxide powder; and carrying out two-step reduction with pure hydrogen in the tubular furnace to obtain the tungsten-doped superfine yttrium oxide compound powder. The average grain size is about 10nm, the grain size distribution is extremely narrow, and a bimodal distribution phenomenon is avoided.

A method for preparing a PTC material by compounding polyaniline/carbon black/polyolefin comprises the steps as follows: step one, the carbon black and aniline are processed; step two: the aniline is added to a hydrochloric acid solution, and then the carbon black is added; step three: the formed solution is subjected to ultrasonic dispersion, and a ammonium persulfate hydrochloric acid solution is dropwise added into the solution; step four: a formed polyaniline/carbon black product is washed and leached repeatedly with deionized water; step five: high-density polyethylene and polyaniline/carbon black are uniformly refined in a banbury mixer; step six: a product is discharged, batched-off and subjected to grain-sized dicing; and step seven: sheet materials are sheeted on a slab vulcanization machine tool, and plastic particles are extruded to form self-temperature-limiting heating/heat tracing cables, and then electronic radiation crosslinking is realized; and in the step one, the carbon black is placed in a vacuum drying oven and dried to the constant weight, and the aniline is processed through pressure reduction distillation. According to the method, reaggregation of carbon black particles is prevented, so that particles are uniformly distributed, and the performance of the PTC material is remarkably improved.

The invention relates to a preparation method of a yolk-shell structure molybdenum disulfide@ carbon electrode material. The preparation method includes: utilizing molybdenum disulfide precursor solvothermal ethylene glycol to obtain monodisperse molybdenum disulfide nanospheres; allowing dopamine to self-polymerize on the interfaces of molybdenum disulfide particles to obtain a molybdenum disulfide@ polydopamine core-shell structure, and performing high-temperature carbonization on molybdenum disulfide@ polydopamine to obtain core-shell structure molybdenum disulfide@ carbon nanoparticles; dispersing molybdenum disulfide@ carbon in a hydrogen peroxide solution for hydrogen peroxide etching to obtain the yolk-shell structure molybdenum disulfide@ carbon material. A gap between molybdenum disulfide and a carbon shell can be well regulated by adjusting concentration of hydrogen peroxide. When the concentration of hydrogen peroxide is 0.4vol%, discharging specific capacity of a prepared yolk-shell structure molybdenum disulfide@ carbon lithium ion battery cathode in the second circle is up to 1167mAh g-1, discharging specific capacity after being circulated for 200 circles is 880mAh g-1, capacity retaining rate is 75.4%, and rate performance is outstanding.

The invention relates to a preparation method of environment-friendly hydrotalcite-like nanosheets, and belongs to the technical field of preparation of two-dimensional nano materials. Through the preparation method, complexity of the process, difficult recovery of organic solvents and other problems are solved in an existing process of nanosheet preparation by using a hydrotalcite-like compound as a precursor. The preparation method comprises the steps: dispersing the hydrotalcite-like compound and a stabilizer in anhydrous ethanol, adjusting the temperature and pressure so as to keep ethanolat a supercritical state for a period of time, and returning to the state of normal temperature and normal pressure so as to obtain the hydrotalcite-like nanosheets. Through conversion of ethanol between a supercritical state and a conventional state, the hydrotalcite-like compound is stripped effectively, and recycling use of ethanol is achieved. The disadvantages that multiple times of ion exchange are needed in the conventional method, and use of formamide and other organic solvents is needed are avoided, and the preparation method has the characteristics of environmental friendliness, a simple process and low cost.

The invention relates to a method for initiating polymer grafting treatment on carbon black surface by utilizing gamma ray radiation, belonging to the technical field of high molecule polymer graftingchemical treatment. The method mainly comprises the following process: first, preparing carbon black dispersed liquid sizing agent which contains a certain quantity of carbon black powder particles and is evenly dispersed inside distilled water, and then adding polymer monomer butyl methacrylate, styrene and acrylonitrile mixed monomer emulsion into the sizing agent. The mixed monomer emulsion isprepared by mixed monomer which is prepared by the polymer monomer butyl methacrylate, the styrene and the acrylonitrile mixed monomer emulsion according to the mixture ration of 7:2:1, emulsifier sodium dodecyl sulfate or/and alkylphenol polyethenoxy ether and a certain amount of distilled water, and the weight ratio among the mixed polymer monomer, the emulsifier and the distilled water is 5:1:14, placing the mixed liquid containing the carbon black sizing agent and the monomer emulsion under gamma ray radiation for irradiation treatment, the irradiation dose of the gamma ray is 3-10KGy, and finally, the radiation initiation polymer grafting treatment is carried out on the carbon black surface by gamma ray. After being treated, the carbon black particles have good dispersion stability and uniformity.

The invention relates to high temperature-resistant powder coating and a preparation method thereof. The high temperature-resistant powder coating comprises graphene modified epoxy resin, graphene modified polyester resin, a curing agent, a mica powder, a talc powder, hollow microbeads, a defoamer, a leveling agent, a high temperature-resistant pigment and other auxiliary agents. According to thetechnical scheme, through the addition of the hollow microbeads in the coating, by virtue of the characteristic of good fluidity of the hollow microbeads, the high temperature resistance of the powdercoating is effectively improved; the film forming hardness of the powder coating is adjusted through different hardness of the graphene modified epoxy resin and the graphene modified polyester resin,and through different contents of graphene in the epoxy resin and the polyester resin, after mixing, a bonding force inside the material can prevent reaggregation of the graphene because of capability of forming a disordered structure in a coating layer of the coating and increases the resistance of permeability factors permeating to the surface of a substrate, so that the corrosion resistance ofthe coating is greatly improved.

Disclosed is an inorganic microparticle-dispersed paste composition which can be defatted at low temperature and has excellent dispersibility and storage stability. The inorganic microparticle-dispersed paste composition comprises a (meth)acrylic resin, inorganic microparticles, and an organic solvent. The (meth)acrylic resin has an amino group or an amide group at a molecular end and has a weight average molecular weight in terms of polystyrene of 5000 to 100000.

In order to solve the problems that pigments are poor in wettability and dispersity, high in viscosity and poor in storage stability, a quaternary ammonium salt derivative is applied to preparation of an azo red pigment for water-based UV ink. The invention also relates to the red pigment and a preparation method thereof and further provides the water-based UV red ink using the red pigment. The preparation method of the red pigment comprises the processes of diazotization reaction, coupling liquid preparation, coupling reaction, post-treatment and the like, wherein a quaternary ammonium salt derivative solution is added in the preparation process of coupling liquid, and compound liquid of an anionic surfactant and a nonionic surfactant is added in a post-treatment process. Thus, the pigment has good wettability, high dispersibility, high coloring strength, low viscosity and good storage stability in a water-based UV system.

The invention belongs to the field of pigment yellow synthesis, particularly relates to a high-speed, high-tinting-strength and odorless pigment yellow synthesis method, and aims to solve the problems of high material liquid viscosity, extremely low reaction efficiency, incomplete reaction and the like due to no use of auxiliaries in the existing pigment synthesis process. In order to solve the problems of high bubbling quantity and low reaction efficiency in the prior art, the invention provides the following scheme: the method comprises the following steps: S1, preparing a diazonium solution; s2, preparation of a coupling liquid: 4-chloro-2, 5-dimethoxyacetoacetanilide is subjected to clarification and acid precipitation; and S3, coupling reaction: adding the prepared diazonium liquid into the coupling liquid. The invention has good water solubility, excellent nonionic surfactant, good washing decontamination ability and strong emulsibility, can excellently improve the reaction efficiency effect, can effectively improve the reaction rate, and can shorten the coupling reaction time.

The invention discloses a preparation method of a dispersing agent for a polyurethane coating, and relates to the technical field of coating additives. The preparation method comprises the following steps of: (1) acquiring an initiator solution; (2) acquiring a reaction solution; (3) acquiring a dispersion liquid preparation body; and (4) adding isodecanol and oleylamine into the obtained dispersion liquid preparation body, performing heating to 70-75DEG C under the protection of nitrogen atmosphere, carrying out heat preservation and stirring for 2h, and then performing natural cooling to room temperature to obtain the product. The invention provides a preparation method of the dispersing agent for a polyurethane coating. Compared with a conventional dispersing agent, the dispersing agentdisclosed by the invention has a stronger surface adsorption effect on pigments and fillers, the wetting effect on pigment and filler particles can be obviously improved, the grinding process is shortened, the yield per unit time is increased, an excellent anti-flocculation effect is realized, and re-aggregation of dispersed particles can be prevented, the dispersing agent provided by the invention adopts a non-polar part to provide a three-dimensional barrier among filler particles, and the stability of the filler particles in a solvent system is realized by virtue of a space entropy effect.

The invention discloses a preparation method of a holocellulose nano composite fiber. The preparation method comprises the following steps: a microcrystalline cellulose suspension is ground and centrifugally separated to obtain a cellulose nanocrystalline supernatant, the cellulose nanocrystalline supernatant is added into a cellulose fiber spinning solution to be uniformly mixed, bubbles are removed from the uniformly mixed cellulose nanocrystalline/cellulose fiber spinning solution, and then spinning is conducted, wherein the length of the cellulose nanocrystalline in the supernatant is 223+/-100 nm to 366+/-171 nm, and the diameter of the cellulose nanocrystalline is 29+/-8 nm to 35+/-9 nm. According to the preparation method, the cellulose nanocrystalline can be uniformly dispersed inthe cellulose fiber spinning solution, meanwhile, the dispersion stability of the cellulose nanocrystalline in the spinning solution is improved, reaggregation of the cellulose nanocrystalline is avoided, the cellulose nanocrystalline can be uniformly dispersed in the spinning solution, and finally the mechanical property of the composite fiber is improved.