76 results about "Silicon dioxide nanoparticles" patented technology

The invention relates to the technical field of fire extinguishing microcapsules, in particular to a high-airtightness perfluorohexanone fire extinguishing microcapsule and a preparation method and application thereof.The perfluorohexanone fire extinguishing microcapsule comprises a composite shell layer and a fire extinguishing core, and the composite shell layer is made of ethylene-vinyl alcohol copolymer resin and silicon dioxide nanoparticles; the fire extinguishing core is a perfluorohexanone fire extinguishing agent and is applied to preparation of indoor fire extinguishing pastes, fireproof coatings and polyurethane adhesive materials. According to the perfluorohexanone fire extinguishing microcapsule disclosed by the invention, the diffusion of low-polarity perfluorohexanone is effectively prevented by utilizing the strong hydrogen-bond interaction between hydroxyl groups in the ethylene-vinyl alcohol copolymer resin, and especially under the condition of relatively high temperature, the perfluorohexanone fire extinguishing microcapsule has a good fire extinguishing effect. The problem that an existing perfluorohexanone fire extinguishing microcapsule is poor in long-term air tightness under the condition of high encapsulation efficiency is effectively solved, and meanwhile harmful substances such as formaldehyde cannot be generated.

The invention discloses a high-yield gastrodia elata planting method based on Tilia brachypoda fungus material optimization and seed ramie stress resistance activation. According to the high-yield gastrodia elata planting method based on Tilia brachypoda fungus material optimization and seed ramie stress resistance activation, yield increase and quality improvement are achieved through fungus material composite strengthening treatment and a composite strain synergistic inoculation technology. The method comprises the following steps: (1) fermenting a tilia brachypoda substrate by lactobacillus plantarum and soaking in a nano-composite nutrient solution to form a high-activity bacterial material; (2) nitrogen-fixing bacteria, disease-resistant actinomycetes and armillaria mellea are mixed and inoculated according to the proportion of 3: 1: 1, nitrogen supply is improved, and the occurrence rate of black rot is reduced; 3) activating a GASA stress-resistant gene of the seed hemp through a pulsed electric field (5 kV / cm, 10 microseconds), and enabling the germination rate to reach 88.5% in combination with a calcium signal channel strengthening technology; according to the method, the yield per mu of gastrodia elata is increased by 30%-40%, the gastrodin content is increased by 30% or above, the chemical pesticide dosage is reduced by 55%, the strain passage purity is stable, the method is suitable for large-scale planting in multiple climate areas, and an innovative solution is provided for green production of traditional Chinese medicinal materials.

The invention relates to the field of biomimetic materials, in particular to a biomimetic self-cleaning anti-fouling aquaculture net cage material, a preparation method and application of the biomimetic self-cleaning anti-fouling aquaculture net cage material. 0.5 to 2.0 parts by weight of a carboxylated graphene nanosheet; 2.0 to 5.0 parts by weight of nitrogen-doped titanium dioxide nanoparticles; 1.0 to 3.0 parts by weight of silica nanoparticles; 5.0 to 10.0 parts by weight of calcium ion cross-linked modified sodium alginate; 1.0 to 3.0 parts by weight of octadecyl trichlorosilane; 0.5 to 1.5 parts by weight of lauryl sodium sulfate; through the synergistic effect of a double bionic structure and enhanced photocatalysis, the effective inhibition on attachment of various organisms is realized, and the inhibition rate on attachment organisms such as algae, bacteria and barnacles reaches 75% or above.

The invention discloses a sheet deicing structure, a composite ice dredging coating and a preparation method thereof, and belongs to the technical field of wind power generation. The preparation method of the composite ice-dredging coating comprises the following steps: dispersing silicon dioxide nanoparticles in an organic solvent to form a nanoparticle dispersion liquid with the concentration of 1-10wt%; and then, adding low-surface-energy resin and a curing agent into the nano-particle dispersion liquid, and treating under the ultrasonic action and the ice-water bath condition to obtain the composite ice-dredging coating. In addition, the invention also provides the composite ice-dredging coating prepared by the preparation method. In addition, the invention further provides a blade deicing structure which sequentially comprises a surface anti-icing layer, a heating layer, a heat conduction layer and a structural layer from top to bottom. The surface anti-icing layer is made of the composite ice dredging coating. The composite ice dredging coating provided by the invention realizes effective ice prevention and removal of the blade.

The invention relates to the technical field of films, in particular to a preparation method and application of a waterproof and oil-proof ventilation valve for food packaging. The preparation method comprises the following steps: carrying out plasma activation treatment on the porous polytetrafluoroethylene-based membrane; preparing fluoroalkyl silane modified silicon dioxide nano particles; preparing fluorine-containing organic silicon-silicon dioxide sol containing vinyl; a cross-linking layer is constructed through vacuum impregnation; preparing a hydrophilic / hydrophobic comonomer solution; copolymerized chain grafting is initiated by ultraviolet light; and water-based fluorocarbon emulsion is sprayed on the surface for curing. The obtained breather valve has super-hydrophobic and oleophobic characteristics, keeps high air permeability and high water vapor permeability at the same time, has the air permeability retention rate exceeding 95% after 10 times of moist heat sterilization, and is suitable for balancing internal and external pressure and blocking water and oil phase liquid permeation in the high-temperature and high-pressure sterilization process of a food packaging container.

The invention discloses an electronic skin capable of realizing non-inductive, continuous and sensitive motion monitoring, and belongs to the field of flexible electronics and biomedical engineering. The electronic skin is mainly prepared from sodium alginate and acrylamide to form porous network gel, and the porous network gel is cross-linked to prepare the original porous base electronic skin; preparing solid-like coating paint from silicon dioxide nanoparticles, silicone oil and epoxy resin; the solid-like coating paint is uniformly sprayed on the surface of the original porous-based electronic skin through a spraying technology, and is cured to form the solid-like coating modified electronic skin. The electronic skin with the specific formula and thickness is prepared, and personalized, low-cost, portable, wireless, non-inductive, continuous and sensitive motion monitoring can be achieved.

The invention discloses a nano composite ionic gel material with impact resistance and a preparation method thereof, and belongs to the field of polymer composite materials. The preparation method comprises the following steps: mixing and heating 5-methyl-2-isopropyl phenol and tetrabutylammonium tetrafluoroborate to prepare a solvent, adding isobornyl acrylate, hexafluorobutyl acrylate, KH570 modified silicon dioxide nanoparticles, 2, 6-diphenyl phenoxyethyl acrylate, a photoinitiator and a cross-linking agent into the solvent, and uniformly stirring to obtain the photocuring coating. And carrying out photopolymerization to obtain the nano composite ionic gel material. The nano-composite ionic gel material with impact resistance prepared by the invention is soft in a normal state and low in modulus; and when high-speed impact occurs, rapid and efficient energy dissipation occurs in the interior, the modulus is sharply increased, and the intelligent protection effect of'being rigid when encountering rigid and being flexible when encountering flexible 'can be achieved.

The invention discloses a radiation refrigeration material, a preparation method and a preparation device, and the radiation refrigeration material comprises a primer layer, a middle paint layer and a finish paint layer, the primer layer is doped with titanium dioxide nano particles; the middle paint layer is doped with aluminum oxide or barium sulfate nanoparticles; and the finish paint layer is doped with silicon dioxide nanoparticles and a fluorescent material. The preparation method of the radiation refrigeration material comprises the following steps: S1, respectively preparing the primer, the intermediate paint and the finish paint through weighing, stirring, grinding and filtering processes; s2, the surface of an object is coated with primer, and a primer layer is formed; s3, the surface of the primer layer is coated with intermediate paint, and an intermediate paint layer is formed; and S4, the surface of the middle paint layer is coated with finish paint to form a finish paint layer. The radiation refrigeration material preparation device comprises a stirring barrel, a stirring shaft and a feeding pipe. According to the scheme, the spectral selectivity, durability, environmental friendliness and attractiveness of the refrigeration material can be effectively guaranteed.

The application discloses a kind of low temperature extremely cold environment under optical fiber coating detection equipment and method, belong to coating detection technical field, comprising: obtaining temperature cycle times, coating thickness, heating gradient and other detection condition data, and coating adhesion, shrinkage, cracking length and other performance data;Construct detection condition evaluation model output detection condition coefficient;Based on detection condition, coating performance analysis model is established to output performance evaluation coefficient;Combined with the content of silicon dioxide nanoparticles and polyether polyurethane data, material analysis model is output material analysis coefficient;If the coefficient exceeds the preset threshold, then determine that the coating is unqualified and generate target formulation parameters.The application solves the technical problems of coating performance quantification evaluation and formulation precise optimization under extreme environment, significantly improves detection efficiency and reliability.

The invention discloses a high-speed copper-clad plate material based on an epoxy resin system and a preparation method thereof, and belongs to the technical field of energy conservation and environmental protection. In order to solve the problems that a traditional copper-clad plate is high in dielectric loss, poor in heat conductivity and insufficient in heat resistance, fluorinated silicon dioxide nanoparticles (the surface energy is smaller than or equal to 18 mN / m) are prepared through a sol-gel method, and a boron nitride layer is modified through trisodium citrate and aminopropyltriethoxysilane; mixing with bisphenol A epoxy resin, a reactive diluent, a DOPO flame retardant, dicyandiamide and 2-methylimidazole to obtain a resin adhesive; adding nano filler and deionized water, mixing and defoaming at a high speed, presoaking 2116 glass fiber cloth to prepare a prepreg, laminating, matching with copper foil, performing segmented hot pressing, and performing secondary tempering. Dk of the obtained material is 3.1-3.35, Df is smaller than or equal to 0.0055, Tg is larger than or equal to 165 DEG C, heat conductivity is larger than or equal to 0.59 W / m.K, peel strength is larger than or equal to 1.78 N / mm, T288 is larger than or equal to 40 min, and the material is suitable for 5G high-speed PCBs and has low energy consumption and environmental friendliness.

The invention relates to a high-strength MBR (Membrane Biological Reactor) ultrafiltration membrane, a preparation system and method thereof and a spinning solution. According to the invention, a composite nano reinforcing agent composed of modified silicon dioxide and graphene oxide is innovatively introduced into a membrane solution. The two nano materials form a rigid-flexible synergistic enhanced network in a polymer matrix; the graphene oxide is used as a two-dimensional nanosheet layer, so that stress is effectively transmitted and dispersed; and the silicon dioxide nanoparticles are used as stress concentration points to prevent the propagation of microcracks. Meanwhile, the invention provides a set of composite reinforcement solution. The core of the scheme is that a polyester / polyamide high-density composite braided tube subjected to plasma surface treatment is adopted as a mechanical skeleton of the membrane, and main operation stress is borne from the macroscopic scale. The multi-stage synergistic enhancement mechanism from the macroscopic braided tube to the nanoscale endows the membrane filament with mechanical strength far beyond the conventional level and fatigue and filament breaking resistance.

The utility model relates to the technical field of PC plates, in particular to a PC sunlight plate with an anti-dazzle function. According to the technical scheme, the utility model relates to the PC sunlight plate with the anti-dazzle function, and belongs to the technical field of PC plates. According to the technical scheme, the device comprises a hollow honeycomb layer, a gradient refractive index composite layer and a microprism array. The honeycomb axis of the hollow honeycomb layer and the substrate form an inclination angle of 15 degrees, and the inner wall is coated with the titanium dioxide scattering layer, so that light rays can be effectively scattered, glare is reduced, and heat is insulated. The gradient refractive index composite layer is composed of an outer PC base material plate containing a benzotriazole UV absorbent, a middle PC base material plate doped with silicon dioxide nanoparticles in a gradient mode and an inner antistatic modified PC base material plate, and the gradient refractive index composite layer has the anti-ultraviolet function and the anti-static function. And microprism arrays with the height of 0.2 mm and the spacing of 0.5 mm are uniformly distributed on the PC board, so that the anti-dazzle effect is further optimized. According to the utility model, through cooperative operation of all the structures, excellent anti-dazzle, heat insulation, ultraviolet resistance, stable structure and other characteristics are realized.

The invention relates to the technical field of surface modification of super-hydrophobic materials, in particular to an epoxy super-hydrophobic anticorrosive composite coating as well as a preparation method and application thereof. The epoxy group super-hydrophobic anti-corrosion composite coating is composed of a bottom layer and a surface layer, and the bottom layer and the surface layer form chemical-physical combination through a semi-curing-spraying technology. Wherein the bottom layer is formed by mixing modified hexagonal boron nitride composite filler, epoxy resin, a curing agent and a solvent; the modified hexagonal boron nitride is selected from a nano cerium oxide grafted and modified polydopamine-hexagonal boron nitride or a hydroxylated hexagonal boron nitride loaded cerium-8-hydroxyquinoline complex; and the surface layer is a super-hydrophobic layer formed by fluorosilane modified silicon dioxide nanoparticles or fluorosilane modified silicon carbide nanoparticles. The epoxy group super-hydrophobic anti-corrosion composite coating has excellent super-hydrophobicity, long-acting corrosion resistance, mechanical stability and self-repairing function, and the problems in the prior art are solved.

The application belongs to the technical field of fin materials, and particularly relates to an acid and alkali resistant hydrophobic modified fin, a preparation method and application thereof. The preparation method comprises the following steps: polishing the fin surface to remove the surface oxidation layer and processing marks; washing the polished fin with alkali, then washing with water, and then activating the fin with dilute hydrochloric acid to obtain a pretreated fin; depositing a copper transition layer on the surface of the pretreated fin; preparing a nickel chloride-based liquid phase system, which comprises: 150-250 g / L of nickel chloride hexahydrate, 150-250 g / L of ammonium chloride, 30-50 g / L of boric acid, 0.5-1.5 g / L of multi-walled carbon nanotubes, and 0.6-1.2 g / L of silicon dioxide nanoparticles; immersing the fin with the deposited copper transition layer in the nickel chloride-based liquid phase system to perform electrodeposition; finally, immersing the fin in a trimethoxy(1H, 1H, 2H, 2H-heptadecafluorodecyl) silane ethanol solution, performing light-proof treatment for a set time, washing with water, and drying to obtain a modified fin. The modified fin has both hydrophobic characteristics and acid and alkali corrosion resistance, and can effectively solve the problems existing in the corrosion protection of finned tubes.

The application discloses a kind of nanometer composite ionic gel materials with impact resistance and a preparation method thereof, and belongs to the field of polymer composite materials.The application prepares a solvent by mixing and heating 5-methyl-2-isopropyl phenol and tetrabutylammonium tetrafluoroborate, then adds isobornyl acrylate, hexafluorobutyl acrylate, KH570 modified silicon dioxide nanoparticles, 2,6-diphenyl phenoxy ethyl acrylate, a photoinitiator and a crosslinking agent in the solvent, and the nanometer composite ionic gel material can be obtained after photopolymerization.The nanometer composite ionic gel material prepared by the application is soft and has low modulus in normal state, but when subjected to high-speed impact, rapid and efficient energy dissipation occurs inside, the modulus sharply rises, and the intelligent protection effect of "encountering rigidity to be rigid, encountering softness to be soft" can be realized.

The invention discloses a nano-composite pressure-reducing injection-increasing oil displacement system and a preparation method thereof, and belongs to the technical field of petroleum and natural gas exploitation chemical agents, the nano-composite pressure-reducing injection-increasing oil displacement system comprises: an acid base solution: hydrochloric acid, hydrofluoric acid, ethylenediaminetetra (methylene phosphonic acid) or ethylenediaminetetraacetic acid; a block type quaternary ammonium salt-betaine surfactant; fluorine-modified graphene oxide; modifying the titanium dioxide nano particles by using amino silane; silica nanoparticles; a fluorocarbon discharge aiding agent; an organic silicon defoaming agent; and deionized water. Through the synergistic effect of nano-compounding and molecular design, the integrated performance of pressure reduction, injection increasing and oil displacement is achieved, and the oil displacement agent is suitable for pressure reduction, injection increasing and oil displacement operation under the high-temperature and high-salt reservoir condition.

The invention relates to the technical field of composite materials, in particular to a high-transparency low-haze flame-retardant polycarbonate composite material as well as a preparation method and application thereof. The invention provides a high-transparency and low-haze flame-retardant polycarbonate composite material as well as a preparation method and application thereof, aiming at the problem that modified polycarbonate cannot give consideration to high light transmittance, low haze, high modulus and high flame retardance in the prior art. Comprising polycarbonate resin, cycloolefin copolymer resin, surface fluorinated silicon dioxide nanoparticles, surface modified C-glass fibers, a core-shell structure flame retardant, a potassium perfluorobutanesulfonate ionic liquid complex, an anti-dripping agent, an antioxidant and an ultraviolet absorbent. According to the invention, through PC / COC matrix refractive index matching and surface modified C-glass fiber surface five-layer gradient coating design, an ultralow refractive index is realized, surface fluorinated silica nanoparticles fill interface microdefects, extremely low interface light scattering is realized, and a highly transparent state is presented.

The invention belongs to the technical field of chemical batteries, and discloses a preparation method of a lithium ion battery suitable for a vibration environment. Selecting positive and negative electrode active materials in a specific particle size range and a binder in a specific molecular weight range; one or more of carboxylated oriented carbon nanotubes, epoxy modified polyurethane microspheres and hydroxylated silicon dioxide nanoparticles are added as additives to enhance the structural stability of the electrode and promote stress dispersion; and the current collector and the tabs are connected by adopting a process of winding first and then laminating, ultrasonic welding and nano-silver adhesive auxiliary bonding, so that the battery assembly is completed. According to the invention, the cycle performance, reliability and safety of the lithium ion battery in a vibration environment are remarkably improved, the failure caused by active substance shedding and interface distortion is reduced, and the lithium ion battery is suitable for high-vibration scenes such as electric automobiles, aerospace and ship underwater vehicles.

The invention relates to the technical field of fibers, in particular to an antibacterial fiber, a preparation method thereof and a fabric. According to the method, chinlon 6 slices are taken as a matrix, and construction of an inorganic-organic synergistic internal antibacterial structure is realized through end sealing of a trifluoromethyl thiazolecarboxylic acid-containing end group, grafting of silicon dioxide nanoparticles with temperature-sensitive poly N-isopropylacrylamide and dual-grafting modification of quaternary ammonium salt-isocyanate in sequence; the antibacterial unit in the obtained fiber is fixed in situ through isocyanate-amino condensation and silanol-amide hydrogen bonds, the fiber has the characteristics of high strength, wear resistance, long-acting antibacterial property, odor suppression and humidity regulation, the prepared fabric still keeps excellent antibacterial property after being washed for multiple times, the process is stable, and the fiber is suitable for industrial production.

The invention relates to the technical field of demolding, and particularly discloses a novel semi-permanent superoleophobic demolding agent and a preparation method thereof. The release agent is prepared from the following raw materials in percentage by weight: 1.0 to 3.5 percent of fluorinated polyhedral oligomeric silsesquioxane, 1 to 10 percent of fluorinated silicon dioxide nanoparticles, 1 to 4 percent of alpha-cyanoacrylate adhesive, 1 to 3 percent of perfluoroalkyl silane, 0.1 to 1 percent of pyridine, 0.1 to 0.5 percent of silane coupling agent and the balance of solvent. The release agent disclosed by the invention has the characteristics of excellent super-oleophobicity, excellent wear resistance, outstanding chemical stability, relatively strong adhesive force, wide applicability and the like, can play a good barrier role between a molded surface and a base material, reduces the probability of adhesion between molded parts, and is relatively low in probability of transferring to the surfaces of the molded parts, so that the release agent can be applied to the surface treatment of the molded parts. Therefore, the recoating frequency is obviously reduced, and the labor cost and the material consumption are reduced.

The application discloses a preparation method of a low-refractive composite powder and application thereof. The preparation method of the low-refractive composite powder comprises the following steps: mixing submicron powder with a mixture containing tetraethyl orthosilicate, heating, and reacting under an acidic condition to obtain a first sol slurry; mixing and stirring the first slurry with a binder to obtain a second slurry; and performing spray granulation and calcination on the second slurry to obtain a low-refractive core-shell structure composite powder. According to the technical scheme, the high-refractive or high-absorbance submicron powder, which is not suitable for or cannot be used for 3D printing, is covered with the silicon dioxide nanoparticles formed by the reaction of the mixture containing tetraethyl orthosilicate on the surface of the submicron powder, so that the refractive index or the absorbance of the submicron powder is reduced, the refractive index difference between the ceramic powder material which is difficult to solidify or cannot be solidified and the photosensitive resin is reduced, and the solidification performance of the ceramic material is improved.

The invention relates to the technical field of modified warm mixing agents, and discloses a nano modified warm mixing agent preparation method which comprises the following preparation steps: 1) adding silicon dioxide nanoparticles, titanium dioxide nanoparticles, a surface modifier and a dispersant into deionized water to form a primary mixed solution; 2) adding a sodium hydroxide solution into the primary mixed solution; 3) performing ultrasonic treatment on the primary mixed solution; 4) adding ferric trichloride hexahydrate, ferrous chloride tetrahydrate and a nucleation inhibitor into the primary mixed solution to form a secondary mixed solution; 5) adding a sodium hydroxide solution into the secondary mixed solution; (6) heating and stirring the secondary mixed solution in a reaction kettle to form a reaction mixed solution; 7) separating the silicon dioxide nanoparticles and the titanium dioxide nanoparticles in the reaction mixture to form mixed nanoparticles, and drying the mixed nanoparticles to obtain modified nanoparticles; and 8) mixing the modified nanoparticles with the warm mixing agent to form the nano modified warm mixing agent.

The application discloses a modified glass fiber filter material and a preparation method thereof, adopts polydimethylsiloxane with good strength and strong adhesion as a low surface energy modifier, can reduce the surface energy of the glass fiber filter material, and improves the chemical hydrophobicity; and further uses silicon dioxide nanoparticles as a microstructure regulator, can realize effective cooperation of chemical hydrophobicity and structural hydrophobicity, and further improves the hydrophobic effect of the filter material; the modified preparation method is simple, easy to control, and low in requirement on equipment, and the prepared modified glass fiber filter material has good hydrophobicity and acid resistance, and simultaneously has excellent filtering performance, and can be widely produced and applied.

The invention belongs to the field of preparation of functional nano catalytic materials, and provides a method for rapidly preparing metal-doped SiO2 and TiO2-based photonic crystal catalytic microspheres, which comprises the following steps: S01, adding deionized water and nitric acid into absolute ethyl alcohol to obtain a solution A; s02, adding tetrabutyl titanate and metal acetylacetone salt into absolute ethyl alcohol to obtain a solution B; s03, dropwise adding the solution A into the solution B to obtain a TiO2 precursor dispersion liquid; s04, dispersing silicon dioxide nanoparticles in the TiO2 precursor dispersion liquid, so as to prepare a SiO2 / TiO2 precursor dispersion liquid; s05, taking the SiO2 (at) TiO2 precursor dispersion liquid as a dispersion phase, and shearing the dispersion phase through a continuous phase in the micro-fluidic chip to obtain SiO2 (at) TiO2-based liquid drops; and S06, drying, washing, calcining and modifying the SiO2-coated TiO2-based liquid drops with hydrogen peroxide to obtain the composite material. The method provided by the invention successfully solves the key technical problems of non-uniform size, uncontrollable structure, complex process, difficulty in batch production and the like in the preparation of the high-performance photonic crystal catalytic microspheres, and can greatly improve the preparation efficiency and the yield.

The invention provides photovoltaic cell glass and a manufacturing method thereof. The photovoltaic cell glass comprises a glass substrate; the antireflection layer is arranged on one side of the glass substrate; the antireflection layer is of a structure formed by solid silicon dioxide nanoparticles; the functional composite layer is arranged on one side, far away from the glass substrate, of the antireflection layer; the functional composite layer comprises hollow silicon dioxide nanoparticles and titanium dioxide nanoparticles; and the titanium dioxide nano particles are arranged in gaps between adjacent hollow silicon dioxide nano particles. The antireflection layer and the functional composite layer with specific structures are arranged in the photovoltaic cell glass, so that high light transmittance is realized, and a self-cleaning function is considered.

The application provides a tile back bead effect remover and a preparation method thereof, and belongs to the technical field of building materials. The remover comprises the following components in percentage by mass: 0.5-5% of a silane coupling agent, 2-10% of an acrylate-vinyl versatate copolymer latex powder, 1-8% of silicon dioxide nanoparticles, 8-20% of an alkaline component, 3-10% of a bio-based surfactant, 1-5% of a lipase, 8-20% of an adsorbent, and 40-70% of a filler. The remover can effectively remove the bead effect on the back of the tile, improve the bonding performance of the tile, improve the durability, especially the bonding performance after the tile is soaked and after heat aging, reduce the hollowing phenomenon, and improve the service life of the tile. The remover has low cost, and the raw materials are easy to obtain, low-toxic, environmentally friendly, simple and fast to use, and can improve the construction efficiency and quality, be easy to operate, save cost, and enhance the safety and environmental protection.

The invention relates to a coal mine gas over-limit emergency plugging material in the technical field of coal mine gas over-limit treatment. The coal mine gas over-limit emergency plugging material comprises the following components in percentage by mass: 1.5-2.0% of lauryl sodium sulfate; 5.0% to 8.0% of silica nanoparticles; 3.0%-5.0% of polyvinyl alcohol; 0.5%-1.0% of sodium carboxymethyl cellulose; 0.3%-0.5% of boric acid; 0.2%-0.5% of a silane coupling agent; 0.1%-0.2% of a defoaming agent; and the balance of deionized water. The preparation method comprises the following steps: dissolving the polyvinyl alcohol and the sodium carboxymethyl cellulose in hot water at 60-80 DEG C, stirring until the polyvinyl alcohol and the sodium carboxymethyl cellulose are completely dissolved, cooling to room temperature, adding the lauryl sodium sulfate and the silicon dioxide nanoparticles, stirring and dispersing at a high speed, sequentially adding the boric acid, the silane coupling agent and the defoaming agent, and uniformly stirring at a low speed to obtain the coating. The invention has the advantages of fast curing speed, high early strength, excellent expansion performance, good impermeability, simple preparation process and the like.

The invention discloses a fruit tree grafting growth promoter, and relates to the technical field of fruit tree cultivation. The growth promoter is prepared from the following raw materials in parts by weight: 0.01 to 0.05 part of methyl jasmonate, 0.1 to 0.3 part of salicylic acid nano microcapsules, 2 to 5 parts of bacillus velezensis, 1 to 3 parts of trichoderma harzianum, 5 to 10 parts of mesoporous silica nanoparticles, 3 to 6 parts of zinc alginate compound, 5 to 8 parts of herba portulacae extract, 2 to 4 parts of ginkgo leaf nano extract, 1 to 2 parts of chitosan oligosaccharide, 2 to 4 parts of pullulan and 100 to 200 parts of plasma activated water. The growth promoter disclosed by the invention realizes innovation of an action mechanism, prolongs the action lasting period, breaks through the adaptability limitation of a grafting technology, successfully utilizes and optimizes the micro-ecology of a grafting interface, and is environment-friendly and high in safety.

The invention discloses a composite damping fluid, a preparation method and an elastic viscous composite damping device, and the composite damping fluid is prepared from the following raw materials in parts by weight: 100 parts of polyether type damping fluid, 10-30 parts of silicon dioxide nanoparticles and 50-100 parts of organic solvent, the polyether type damping fluid comprises polyether polyol, epoxy resin and a curing agent; the weight ratio of the polyether polyol to the epoxy resin to the curing agent is 1: (0.5-1): (0.5-1). The device comprises a metal sleeve, a piston with a hole matched with an inner cavity of the metal sleeve, a mandrel connected with the piston with the hole and penetrating through one end of the metal sleeve in a sliding and sealing mode, a spring fixed between the mandrel and the metal sleeve, and composite damping liquid filled in the inner cavity of the metal sleeve. The damping fluid is used for solving the problems that existing damping fluid is limited in damping performance and cannot meet the damping requirement of column type electrical equipment. By adding the silicon dioxide nanoparticles, the viscosity of the damping fluid is enhanced, and the vibration reduction effect is improved.

The application discloses a 4D printing shape memory composite stent for delivering exosomes and magnesium ions and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing hydroxyapatite and silicon dioxide nanoparticles with poly(D, L-lactic acid-co-trimethylene carbonate) in dichloromethane to obtain an oil phase; adding exosomes into a magnesium oxide nanoparticle water dispersion to obtain an aqueous phase; and mixing to obtain a water-in-oil Pickering emulsion; and (2) using a 4D printing technology to prepare the composite porous shape memory stent (PHS / MgO-EXO) loaded with exosomes by using the Pickering emulsion ink. The stent has a multi-stage interconnected pore structure, and can promote cell osteogenic differentiation and bone tissue regeneration by synergistically releasing exosomes and magnesium ions. The stent also has a temperature-sensitive shape memory function, can restore the original shape under a slightly higher body temperature stimulus, can accurately match irregular bone defects, and is suitable for minimally invasive repair treatment of clinical irregular bone defects.