3159 results about "Polyvinylpyrrolidone" patented technology

The invention belongs to the technical field of sodium-ion batteries, and relates to sodium-ion battery positive electrode slurry and a preparation method thereof, and the sodium-ion battery positive electrode slurry comprises a positive electrode active material, a conductive agent, a binder, a dispersant, a slurry stabilizer and a solvent; the positive electrode active material is a transition metal layered oxide material, the conductive agent is one or a combination of more of conductive carbon black, ketjen black, conductive graphite and a carbon nanotube, the binder is polyvinylidene fluoride, the dispersant is polyvinylpyrrolidone, the slurry stabilizer is one or a combination of more of iron oxide, aluminum oxide, zirconium oxide and titanium boride, and the positive electrode active material is a positive electrode active material. The solvent is N-methyl pyrrolidone; in the slurry preparation step, a binder and a solvent are mixed and dissolved to prepare a glue solution; adding a conductive agent and a dispersing agent for dispersing to obtain a conductive adhesive; adding a positive active material and a slurry stabilizer, and dispersing to obtain final slurry; the invention can effectively solve the problem of slurry flocculation in the homogenizing process of the sodium ion battery positive electrode material.

A method for preparing flaky silver powder with the controllable single-crystal structure size comprises the steps that firstly, a silver nitrate aqueous solution is prepared, then a dispersing agent polyvinylpyrrolidone aqueous solution is added and stirred to be uniform, and then a trisodium citrate aqueous solution is added for reacting to prepare nano-silver seed crystals; finally, adding a polyvinyl alcohol aqueous solution serving as an end-capping reagent into the solution, and coating PVA on the crystal face of the nano-silver seed crystal {100} through a grinding dispersion machine to form a nano-silver seed crystal mixed solution containing silver nitrate, polyvinylpyrrolidone and coated PVA; preparing a nitric acid aqueous solution and an ascorbic acid aqueous solution, mixing and adding the nitric acid aqueous solution and the ascorbic acid aqueous solution into a reaction kettle, adding the mixed solution containing silver nitrate, polyvinylpyrrolidone and the PVA-coated nano-silver seed crystal under a stirring condition, and mixing to generate a reduction reaction; the PH value is adjusted through nitric acid to control the reduction reaction speed, the growth direction of nano-silver seed crystals is controlled through PVA, the particle size growth size is controlled through polyvinylpyrrolidone, and finally the flaky silver powder with the controllable single-crystal structure size is obtained.

The invention discloses a Zhejiang camellia japonica clone tissue culture and rapid propagation method. A Zhejiang camellia japonica clone tissue culture and rapid propagation technical system is established by taking a non-lignified tender stem as an explant, sterilizing and then performing primary induction, subculture multiplication, strong bud culture and rooting culture. The explants are soaked before primary inoculation, and vitamin C and polyvinylpyrrolidone with certain concentration are added into a primary induction culture medium, so that browning of the explants can be effectively inhibited; hormone regulation and control and nutrient addition are combined, so that the primary induction rate reaches up to 95.3%, the multiplication coefficient reaches about 6.8, the rooting rate reaches 83.5%, efficient and rapid propagation can be realized, and the method is not limited by factors such as seasons, climate and regions. The rapid propagation offspring obtained by the system can maintain all excellent characters of a stock plant, and the strong bud obtained in the process can be used as a scion for grafting propagation, so that a technical support is provided for protection, development and utilization of rare germplasm resources and excellent clone of the Zhejiang red camellia.

The invention discloses a multifunctional coating with flame retardance, bacteriostasis and electromagnetic shielding as well as preparation and application of the multifunctional coating, and belongs to the technical field of textiles. The preparation method comprises the following steps: firstly, preparing a flame-retardant solution by combining phosphorylated sodium alginate and MXene, and padding a fabric into the solution to obtain a fabric with a flame-retardant function; the preparation method comprises the following steps: preparing a flame-retardant solution, adsorbing zanthoxylum bungeanum essential oil by adopting mesoporous silica to prepare a bacteriostatic agent solution, mixing the flame-retardant solution, the bacteriostatic agent solution and polyvinylpyrrolidone to obtain a flame-retardant and bacteriostatic composite solution, and padding a fabric into the flame-retardant and bacteriostatic composite solution to obtain a fabric with flame-retardant and bacteriostatic functions; mXene solution is sprayed on the fabric with the flame-retardant and antibacterial functions to serve as an enhanced electromagnetic shielding layer, and the multifunctional fabric with the flame-retardant, antibacterial and electromagnetic shielding functions is prepared. The flame-retardant solution and the bacteriostatic agent solution are both made of bio-based materials, have the advantages of being low in price, environmentally friendly and degradable, and can also be used as coatings to be applied to multiple fields.

The invention provides a nitrification inhibitor and a preparation method thereof as well as stable urea and a preparation method thereof, and relates to the technical field of fertilizers. The nitrification inhibitor provided by the invention is prepared from the following components in percentage by mass: 20 to 45 percent of 3, 4-dimethyl pyrazole phosphate (DMPP), 30 to 70 percent of amino acid and the balance of auxiliaries, the auxiliary agent is one or more of polysaccharide, polyvinylpyrrolidone, poloxamer and carbomer. According to the invention, the DMPP and the amino acid are compounded, the amino acid is used as a stabilizer of the DMPP, so that the stability of the DMPP can be remarkably improved, and meanwhile, the polymer additive is used as an adhesive, so that the stability of the DMPP can be further improved. The nitrification inhibitor provided by the invention has excellent stability; the stable urea can be obtained by adopting an endogenous adding mode and adding the stable urea into the urea with relatively low loss, and the stable urea has multiple effects of improving the urea utilization rate, improving the crop quality, improving the soil biological environment, improving the soil fertility and the like.

The invention discloses high-thermal-conductivity carbon black and a preparation method and application thereof, and relates to the technical field of carbon black modification.The preparation method of the high-thermal-conductivity carbon black comprises the following steps that carbon black is subjected to oxidation treatment, silanization treatment and tannic acid coating treatment, and modified carbon black is obtained; preparing a graphene / boron nitride / modified carbon black multi-dimensional filler; carrying out primary modification on the graphene / boron nitride / modified carbon black multi-dimensional filler by adopting lignin, polyvinylpyrrolidone and samarium chloride, and then carrying out secondary modification by adopting 6-aminocaproic acid to obtain the high-thermal-conductivity carbon black. The high-thermal-conductivity carbon black prepared by the invention not only has good dispersity, but also can well improve the thermal conductivity and mechanical properties of a rubber matrix.

The invention relates to the technical field of carbon nanotube materials, in particular to high-dispersity carbon nanotube slurry and a preparation method thereof. Ammonium chloride, sodium azide, novolac epoxy resin and carbon nanotubes are added for modification treatment, and the modified carbon nanotubes are obtained. Then, a silane coupling agent KH550, an MXene material, a palmitic acid solution, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide are added and mixed, and the modified MXene material is obtained. And performing ultrasonic dispersion on polyvinylpyrrolidone, N-methyl pyrrolidone, the modified carbon nanotubes and the modified MXene material to obtain the composite conductive filler. The finished product is obtained by adding the surfactant, the deionized water and the composite conductive filler. The finished product prepared by the method has good conductivity and dispersity, so that the finished product has a wide application prospect in the technical field of carbon nanotube materials.

The invention discloses a preparation method and application of a carbon-loaded cobalt nanoparticle and iron monatomic electro-catalytic material, relates to a preparation and regulation method of a zinc air battery cathode catalyst, and solves the problems of low electricity generation performance and poor stability of an existing rechargeable zinc air battery cathode. Specifically, a high-efficiency and stable-catalysis carbon-loaded cobalt nanoparticle and iron monatomic electro-catalysis material is reasonably designed and successfully synthesized by utilizing the adsorption effect of a metal organic framework (MOFs) and polyvinylpyrrolidone as an ion adsorption layer, and under the condition that active sites are not sacrificed, the high-efficiency and stable-catalysis carbon-loaded cobalt nanoparticle and iron monatomic electro-catalysis material can be used for preparing a high-efficiency and stable-catalysis carbon-loaded cobalt nanoparticle / iron monatomic electro-catalysis material. And the dispersity of cobalt nanoparticles and the catalytic activity of iron monatomic are improved. The obtained material is used as a zinc air battery cathode material, the overall performance of a rechargeable zinc air battery can be improved, and efficient and oriented conversion of the zinc air battery is achieved.

The invention relates to a preparation method of a silver nanowire based on a phenolic compound and the silver nanowire, and the preparation method comprises the following steps: 1, respectively dissolving polyvinylpyrrolidone, small molecular phenolic acid, halide, a silver source and the phenolic compound in deionized water to obtain respective solutions; 2, sequentially adding a polyvinylpyrrolidone solution, a small molecular phenolic acid solution, a halide solution and a silver source solution, and stirring to obtain a reaction solution A; step 3, adding a phenolic compound solution into the reaction solution A to obtain a reaction system B, and stirring and reacting to obtain a mixed solution C containing silver nanowires; fourthly, the mixed solution C containing the silver nanowires is sequentially centrifuged and washed, and then the silver nanowires are prepared; the diameter of the silver nanowire is 20-150 nm, and the length of the silver nanowire is 5-100 [mu] m. Therefore, according to the design, water is adopted as a solvent to synthesize the silver nanowire, the reaction temperature is low, and the reaction speed is high.

The invention provides a bismuth oxybromide-based photocatalytic material, and a preparation method and application thereof, and the preparation method comprises the following steps: (1) dissolving bismuth nitrate pentahydrate and polyvinylpyrrolidone in an alcoholic solution, rapidly stirring to obtain a mixed solution, adding potassium bromide into the mixed solution, and continuing to fully stir for reaction; and (2) transferring the mixed solution into a reaction kettle with a polytetrafluoroethylene lining, carrying out solvothermal reaction, carrying out centrifugal suction filtration separation on the obtained product, washing and drying to obtain the photocatalytic material. The bismuth oxybromide-based photocatalytic material, the preparation method and the application have the advantages that the bismuth oxybromide-based photocatalytic material is excellent in performance and high in visible light response capability, dyes can be quickly degraded in a short time, and the treatment efficiency of printing and dyeing wastewater can be obviously improved.

The invention belongs to the technical field of water electrolysis hydrogen production diaphragms, and relates to coating slurry for a composite diaphragm in an alkaline electrolytic cell and a preparation method of the coating slurry. The coating slurry comprises a high-molecular polymer, an inorganic hydrophilic oxide, a polymer electrolyte, a pore-foaming agent and an organic solvent. The high-molecular polymer is polysulfone, and the inorganic hydrophilic oxide is titanium dioxide; and the polymer electrolyte is acacia gum. And the pore-foaming agent is polyvinylpyrrolidone. Titanium dioxide is used as a filler, so that the hydrophilicity of the hydrophobic polysulfone membrane can be improved, and the transfer of hydroxyl ions is facilitated. Hydroxyl, amino and other hydrophilic groups of the acacia gum are migrated to a membrane-water interface, and the groups and a membrane matrix are combined to form a hydrogen bond network, so that the stability and the water adsorption capacity of the membrane are enhanced, and the composite membrane with low surface resistance, smooth surface, compact coating and good mechanical capacity is obtained. The nylon and the acacia gum are adopted, cost is low, and large-scale production is facilitated.

The invention relates to hydrogel loaded with oxygen self-producing nanoparticles as well as a preparation method and application of the hydrogel. The preparation method comprises the following steps: 1, taking cross-linked methacrylamide silk fibroin and hyaluronic acid modified by arginine-glycine-aspartic acid peptide as base materials, and loading self-oxygen-producing nano particles CaO2 (at) PVP (at) Cu-EGCG, and the self-oxygen-producing nano particles CaO2 (at) PVP (at) Cu-EGCG are prepared by coating Cu-EGCG on calcium peroxide nano particles modified by PVP modified polyvinylpyrrolidone. The hydrogel can improve energy metabolism and regulate immune environment through dual mechanisms, realizes efficient promotion of myocardial repair, and provides a new strategy and thought for tissue regeneration and functional recovery after myocardial infarction.

The invention discloses an anti-tumor nano material based on copper death promotion as well as a preparation method and application of the anti-tumor nano material. The anti-tumor nano material is constructed by taking PCN-Cu as a metal organic framework compound and merging Pt nano particles with stable polyvinylpyrrolidone into the PCN-Cu, and the anti-tumor nano material is named as Pt-coated PCN-Cu. Experiments prove that the Pt-coated PCN-Cu can improve the concentration of copper ions in tumor cells, promote the lipoic acylation aggregation process of mitochondrial related proteins, promote degradation and proteotoxicity reaction of Fe-S cluster proteins and induce copper death of the tumor cells. The Pt-coated PCN-Cu has the advantages of being simple in preparation process, green, economical, low in cost, capable of being produced on a large scale and the like, has a good anti-tumor effect, expands a novel treatment mode for promoting tumor cell copper death, and provides a new technical means for tumor treatment.

The invention belongs to the technical field of phase-change ceramic fiber aerogel, and discloses high-temperature phase-change heat-insulation ceramic fiber aerogel and a preparation method thereof.The preparation method comprises the steps that polycarbosilane and polyvinylpyrrolidone are added into an organic solvent to be mixed and stirred till the polycarbosilane and the polyvinylpyrrolidone are completely dissolved, and a precursor solution is obtained; dispersing a high-temperature phase change microcapsule into the precursor solution, and stirring until the high-temperature phase change microcapsule is uniformly dispersed to obtain a spinning solution; a ceramic precursor fiber membrane is obtained through electrostatic spinning, and the high-temperature phase-change heat-insulation ceramic fiber aerogel is obtained through cross-linking curing and sintering. The thermal conductivity of the high-temperature phase-change heat-insulation ceramic fiber aerogel is adjustable between 0.03 W / (m.k) and 0.05 W / (m.k), the phase-change temperature ranges from 550 DEG C to 600 DEG C, and the phase-change enthalpy value ranges from 400 J / g to 500 J / g. Compared with traditional ceramic aerogel, the aerogel can regulate and control the environment temperature, is more resistant to high temperature and safer, and has wide application in the field of high-temperature heat insulation of aviation power batteries.

The invention belongs to the technical field of veterinary preparations, and particularly relates to a tilmicosin premix and a preparation method thereof. The tilmicosin premix is prepared from the following raw materials: tilmicosin, a polylactic acid-glycolic acid copolymer, lecithin, modified hydroxypropyl methyl cellulose, grafted polyvinylpyrrolidone, polyethylene glycol and an antioxidant, a solid dispersion is formed through lecithin and grafted polyvinylpyrrolidone, the solubility and stability of tilmicosin are enhanced, polylactic acid-glycolic acid copolymer nano-microspheres are prepared through a double-emulsion solvent evaporation method, slow release of drugs is achieved, dodecyl modified hydroxypropyl methyl cellulose and polyethylene glycol are combined, and the sustained release effect is achieved. The solubility and the slow release characteristic are further enhanced. The activity of the granular premix is effectively preserved, and the granular premix is convenient to use and transport.

The invention discloses an oxygen-sulfur double-vacancy modified SnO2 / SnS2 / C nano material as well as a preparation method and application thereof, and belongs to the technical field of electrode materials. The preparation method comprises the following steps: mixing a structure regulating agent with tin salt, dropwise adding alkali liquor, stirring, and carrying out suction filtration to obtain Sn6O4 (OH) 4; the preparation method comprises the following steps: adding glucose and polyvinylpyrrolidone into distilled water, stirring to form a uniform solution, adding Sn6O4 (OH) 4 into the uniform solution, stirring, and carrying out ultrasonic and hydrothermal reaction to obtain SnO2 / glucose; and calcining the SnO2 / glucose and a sulfur source in an inert atmosphere to obtain the SnO2 / SnS2 / C nano material modified by oxygen and sulfur double vacancies. The SnO2 / SnS2 / C disclosed by the invention is used for a lithium / sodium ion battery negative electrode, can effectively relieve volume expansion of tin-based oxysulfide and improve the conductivity of an electrode material, and shows high charge-discharge specific capacity, excellent rate capability and high-rate long-cycle stability.

The invention relates to a self-repairing waterborne polyurethane composite elastomer based on dynamic interface reinforcing and toughening as well as a preparation method and application thereof, and belongs to the technical field of self-repairing high polymer materials. The method comprises the following steps: preparing a waterborne polyurethane emulsion; the preparation method comprises the following steps: uniformly dispersing polyvinylpyrrolidone in an ethanol solution, adding polyfunctional mercaptan and polyfunctional isocyanate, and adding an amino-containing imidazole monomer to obtain microsphere powder; and uniformly dispersing the microsphere powder in a waterborne polyurethane emulsion, adding a metal salt solution, and then volatilizing water to form a film material, thereby obtaining the self-repairing waterborne polyurethane composite elastomer based on dynamic interface reinforcement and toughening. The self-repairing waterborne polyurethane elastomer with excellent comprehensive performance is obtained by designing the structure of waterborne polyurethane, modifying the surface of the microsphere and introducing a dynamic interface for compounding, and the strength, the toughness and the self-repairing capability of the elastomer are simultaneously improved.

The invention discloses a gas-sensitive material for monitoring an environment-friendly gas characteristic substance CO as well as a preparation method and application thereof, and relates to the technical field of gas-sensitive materials. The preparation method comprises the following steps: dissolving tin tetrachloride pentahydrate, sodium hydroxide and polyvinylpyrrolidone, adding ammonium fluoride, reacting at 155-165 DEG C, drying the product, and calcining at 295-305 DEG C to obtain SnO2 nanoparticles; the preparation method comprises the following steps: performing ultrasonic mixing on SnO2 deionized water dispersion liquid and MoS2 nanosheet ethylene glycol dispersion liquid, and then drying to obtain the MoS2 / SnO2 composite material with a mesoporous hollow nanotube structure, and the volume ratio of ethylene glycol to deionized water is (0.9-1.1): 1. The MoS2 / SnO2 gas sensitive material has the advantages of low density, high pore volume, large specific surface area, high structural stability and the like. And when applied to a CO resistive sensor, the catalyst has good CO selectivity, high sensitivity and good long-term stability.

The invention discloses nanoscale bismuth hydroxide as well as a preparation method and application thereof. The invention provides a preparation method of bismuth hydroxide. The preparation method comprises the following steps: reacting a mixture solution of a surfactant solution and a bismuth source solution at the temperature of 100-300 DEG C and the pressure of 0.5-5 MPa to obtain bismuth hydroxide, the pH value of the mixture liquid is 5-12; the bismuth source is bismuth nitrate; the surfactant is selected from polyvinylpyrrolidone or hexadecyl trimethyl ammonium bromide. According to the preparation method, bismuth hydroxide with the microscopic primary particle size of about 40-90 nm, uniform distribution, the secondary particle size D99 of 2-4 microns, the purity of 99.9% and the particle size of more than 99.9% can be obtained, and the adsorption rate of bismuth hydroxide to bromide ions and iodide ions reaches 80% or more.

The invention relates to the technical field of conductive materials, in particular to a high-concentration dispersion system and a preparation method thereof. The high-concentration dispersion system comprises a conductive agent, a dispersing agent, a solvent and a viscosity reduction auxiliary agent, the conductive agent is modified carbon nanotubes, the dispersing agent is modified polyvinylpyrrolidone, the solvent is N-methyl pyrrolidone or deionized water, and the viscosity reduction auxiliary agent is piperazine anhydrous; wherein the modified carbon nano tube is obtained by mixing and heating a carbon nano tube and a mixed acid solution of nitric acid and sulfuric acid, then cooling, filtering, washing, drying, then dispersing in 75% ethanol, and finally adding 3-[3-carboxyl allylamido] propyltriethoxysilane for modification; the modified polyvinylpyrrolidone is obtained by heating polyvinylpyrrolidone at 310-330 DEG C and then oxidizing the polyvinylpyrrolidone. The conductive agent content of the high-concentration dispersion system is high, the conductive agent accounts for 15%-20% of the high-concentration dispersion system by mass, and the high-concentration dispersion system is low in viscosity, high in dispersity and good in conductivity.

The invention provides a diaphragm and a preparation method thereof and a lithium ion battery, the diaphragm comprises a base membrane layer and a composite functional layer, the composite functional layer comprises hydrophobic SiO2 aerogel modified by a hydrophobic agent, a conductive ion polymer and a solid electrolyte, and the composite functional layer respectively accounts for 3-12wt%, 0.5-1.0 wt% and 0.5-1.5 wt% of the total mass of the diaphragm; the hydrophobic agent comprises trimethylchlorosilane, hexamethyldisilazane, perfluorooctyltriethoxysilane, polyvinylidene fluoride, polydimethylsiloxane and the like, the conductive ionic polymer comprises polyvinylpyrrolidone, lithium polymethacrylate, lithium polystyrene sulfonate, polyacrylamide and the like, and the solid electrolyte comprises lithium lanthanum titanium oxide, lithium lanthanum zirconium oxide, lithium lanthanum zirconium tantalum oxide and the like. The wettability is improved by the high porosity of the hydrophobic SiO2 aerogel, the stability and strong conductivity of a physical conductive network of the solid electrolyte and the ion affinity and amphoteric binding capacity of the conductive ion polymer are optimized, the electrochemical performance and thermal stability of the interface are optimized, and comprehensive optimization of the thermal-electric-interface performance of the diaphragm is realized through combination.

The invention relates to the field of coating materials, and provides an antiskid coating based on carbon fibers and a preparation method thereof. The coating is composed of a component A and a component B, the component A comprises KH-570 silane coupling agent surface modified carbon fibers, dog bone-shaped nano silicon dioxide, epoxy modified hydroxy acrylic resin, quartz sand antiskid aggregate, propylene glycol methyl ether acetate, iron oxide pigment and other auxiliaries, and the component B is an HDI tripolymer curing agent. The surface modified carbon fiber is prepared through the steps of cleaning and activating, silane coupling agent dipping, drying and curing and the like, and the dog bone-shaped nano silicon dioxide is prepared through a sol-gel method with hexadecyl trimethyl ammonium bromide and polyvinylpyrrolidone as morphology guiding agents. The preparation method comprises the steps of iron oxide color paste preparation, functional component dispersion, quartz sand addition, curing treatment, double-component mixing and curing and the like. The coating has excellent dry skid resistance, wet skid resistance, wear resistance and durability, and is suitable for the field of ground skid resistance coating.

The invention provides a low-molar-concentration I < + > stabilizer / zinc salt aqueous zinc-iodine battery electrolyte and an aqueous zinc-iodine battery, and belongs to the technical field of aqueous zinc-iodine battery electrolytes.The electrolyte comprises the following chemical components: an I < + > stabilizer, other zinc salts, a multi-iodide ion complexing agent, a diluent and water; in the electrolyte, the concentration of the I + stabilizer is 0.5-1.5 mol / L, the concentration of the other zinc salt is 0.5-2.5 mol / L, the mass fraction of the multi-iodide ion complexing agent is 3-15%, and the volume ratio of the diluent to the water is 1: (3-19); the multi-iodide ion complexing agent comprises at least one of polyvinyl alcohol, polyethylene glycol and polyvinylpyrrolidone. The electrolyte can still realize high coulombic efficiency of the aqueous zinc-iodine battery in the presence of a low-molar-concentration I < + > stabilizer / zinc salt, and also can inhibit side reaction at one end of a zinc negative electrode in the cyclic process of the aqueous zinc-iodine battery, shuttle effect of multi-iodide ions in the I- / I2 conversion process at one end of an iodine positive electrode and hydrolysis of I < + > in the I2 / I < + > process, so that the cycle life of the battery is prolonged, and the service life of the battery is prolonged. And the working temperature range is widened, so that the device can stably operate under severe conditions.

The invention discloses a cerium-modified manganese-based NH3-SCR (Selective Catalytic Reduction) denitration catalyst as well as a preparation method and application thereof. The catalyst is obtained by uniformly mixing and stirring manganous nitrate, cerous nitrate, polyvinylpyrrolidone, citric acid and deionized water, stirring and evaporating to a gel state, drying to form a precursor, and roasting the precursor in an air atmosphere. Ce is used for modifying MnOx, polyvinylpyrrolidone and citric acid are used as a surfactant and a complexing agent in the preparation process of the catalyst, the interaction between Ce and Mn is enhanced, the phase of the catalyst is adjusted, and under the conditions of high NOx concentration (1000 ppm) and high space velocity (GHSV = 120,000 mL h <-1 > g <-1 >), the catalyst can be used for preparing the catalyst, and the catalyst can be used for preparing the catalyst. The catalyst has excellent low-temperature catalytic activity, a wide working temperature window and good reaction stability, and has good water resistance and sulfur dioxide poisoning resistance.

The invention discloses a starch-based full-biodegradable mulching film capable of being rapidly degraded and a preparation method of the starch-based full-biodegradable mulching film, and belongs to the technical field of degradable materials.The preparation method comprises the steps of tea polyphenol calcium salt preparation, filler preparation, thermal plasticization and film preparation. The preparation of the filler comprises the following steps: adding silicon dioxide into a polyacrylic acid aqueous solution, stirring and centrifuging at room temperature, taking a precipitate, adding the precipitate into a polyvinylpyrrolidone aqueous solution, adjusting the pH value to 3-3.5, stirring and centrifuging at room temperature, taking the precipitate, adding the precipitate into the polyacrylic acid aqueous solution, adjusting the pH value to 3-3.5, stirring and centrifuging at room temperature, taking the precipitate, and freeze-drying to obtain the filler. The starch-based full-biodegradable mulching film prepared by the preparation method disclosed by the invention is good in processability, waterproofness and heat resistance and high in mechanical strength, the problem of phase separation does not occur in preparation, the problem of plasticizer precipitation does not easily occur in long-term use, and rapid degradation can be realized.

The invention provides a polyphenol-metal nanodot as well as a preparation method and application thereof, and belongs to the technical field of biological materials. The preparation method of the polyphenol-metal nanodot provided by the invention comprises the following steps: mixing hydrophobic polyphenol, metal salt, polyvinylpyrrolidone and a solvent, and carrying out a coordination reaction to obtain the polyphenol-metal nanodot. Polyphenols have good biomedical application potential, metal salt is added to coordinate with the polyphenols to enrich the functions of the polyphenols, and polyvinylpyrrolidone is added to further optimize the dispersity of the polyphenols in water, so that the polyphenol-metal nanodots are obtained. The nanodot has good dispersity in water, and the application range of polyphenol is widened. Experimental results show that the prepared polyphenol-metal nanodot still has good dispersity when the dispersion concentration in water is 1.24 mg / mL (wherein the concentration of rutin is about 0.86 mg / mL).

The invention discloses a bimetal MOFs-loaded electrostatic spinning fiber membrane for oil-water separation and a preparation method thereof, and belongs to the technical field of membrane separation, and the preparation method comprises the following steps: (1) preparing a hydroxyl-modified metal organic framework material MIL-53 (Al)-OH through a solvothermal reaction; (2) preparing an MIL-53 (Fe) precursor solution by using ferric salt, terephthalic acid, polyvinylpyrrolidone and an organic solvent, ultrasonically dispersing MIL-53 (Al)-OH in the MIL-53 (Fe) precursor solution, uniformly mixing, and soaking the electrostatic spinning fiber membrane in the MIL-53 (Fe) precursor solution for 1-3 hours; and (3) transferring the system in the step (2) into a reaction kettle, reacting at 130-150 DEG C for 10-15 hours to enable the bimetallic MOFs to grow on the surface of the electrostatic spinning fiber membrane, washing, and drying to obtain the bimetallic MOFs-loaded electrostatic spinning fiber membrane for oil-water separation. The bimetal MOFs-loaded electrostatic spinning fiber membrane has the advantages of good oil-water separation performance, strong antifouling ability and strong dye degradation ability.

The invention belongs to the technical field of new materials, and particularly relates to a PEDOT electromagnetic shielding polymer film, a preparation method and application, a substrate coated with an oxidizing agent solution is subjected to a polymerization reaction in steam containing an EDOT monomer, then an oxidizing agent is removed, drying is performed, and the PEDOT electromagnetic shielding polymer film is obtained; the oxidant solution comprises ferric salt, an additive and water, and the additive is one or more of polyvinyl alcohol, polyvinylpyrrolidone, starch, polyethylene glycol and a polyoxypropylene polyoxyethylene copolymer; the PEDOT electromagnetic shielding polymer film provided by the invention has relatively high density and lower resistance, and can improve the electromagnetic shielding effect.

The invention provides micron blocky and submicron spherical mixed silver powder and a preparation method thereof. The preparation method comprises the steps that firstly, a silver salt solution is prepared, a reducing agent, a dispersing agent and pure water are mixed to obtain a reducing agent solution, and nano-silver crystal suspension liquid and the dispersing agent are mixed to obtain a base solution; synchronously dropwise adding the silver salt solution and the reducing agent solution into the base solution to obtain a solution containing the mixed silver powder; and finally, the solution is subjected to washing, solid-liquid separation and drying and shaping treatment, and then the micron blocky and submicron spherical mixed silver powder is obtained. According to the preparation method, polyvinylpyrrolidone with low molecular weight is selected as a dispersing agent, and the adding process of the dispersing agent is controlled, so that nano-silver crystals and the dispersing agent play a synergistic role, the micron blocky and submicron spherical mixed silver powder with good dispersion uniformity and high tap density is obtained, and the mixed silver powder is better in stacking structure and high in conductivity after being formed into slurry; the preparation method provided by the invention simplifies the process steps, shortens the preparation time, and has industrial application prospects.

A dry eye composition containing hypochlorous acid and a demulcent. The demulcent can be polyvinylpyrrolidoe with a molecular weight of 30-50 kDa. The composition can be applied to the surface of the eye with a dropper device or a spray dispenser. Critically, hypochlorous acid is stable in the dry eye composition and maintains its effectiveness at preventing microbial growth.