2456 results about "Tannic acid" patented technology

The invention belongs to the technical field of hydrogel materials, and particularly relates to a preparation method of carbon dot-based super-strong hydrogel. The carbon-dot-based super-strong hydrogel is prepared by taking specific carbon dots (citric acid carbon dots, tannic acid carbon dots, malic acid carbon dots or bark carbon dots) as nano-filler and salting-out-assisted progressive stretching, the specific carbon dots are used as the nano-filler, and the HofMichast effect sensitive characteristic of polyvinyl alcohol is utilized, so that the carbon-dot-based super-strong hydrogel is prepared. Carbon dots and salting-out progressive stretching are combined to construct the super-strong hydrogel, and the super-strong hydrogel is simple in preparation process and excellent in performance.

The invention belongs to the field of paper products, and particularly relates to a heat-sealing coating composition for paper products and application of the heat-sealing coating composition, the coating composition comprises a component A, a component B, a component C and a component D, the component A is one or two of a biomass material with a dendritic or network structure or a cationized biomass material with a dendritic or network structure; the component B is selected from one, two or more of polyhydroxyalkanoate, alkyl ketene dimer, polyglycolide, polylactide, copolymer of butylene adipate and butylene terephthalate, cellulose ester and cellulose ether; and the component C is selected from one, two or more of thermoplastic cellulose and derivatives thereof, thermoplastic starch, rosin, cardanol-based epoxy resin, epoxidized soybean oil, epoxidized castor oil, tannic acid and malic acid. The coating composition is simple in preparation process and easy to industrialize, a target mixture can be obtained through physical blending, and the coating composition is low in production cost, energy-saving and environment-friendly.

The preparation method comprises the following steps: mixing a tannic acid solution and a tetravalent cerium salt solution, adjusting the pH value to 9-11, and reacting to obtain the cerium tannate nano-enzyme, the molar ratio of the tannic acid to the tetravalent cerium salt is (1-4): 1; the hydration dynamic diameter of the cerium tannate nano-enzyme is 20 to 80 nm. The TA-Ce nano-enzyme prepared by the preparation method disclosed by the invention is smaller in particle size, can keep stable and good dispersibility in a physiological environment, and has good biocompatibility, low hemolysis rate and small systemic toxicity; meanwhile, the compound has good kidney targeting property, can be effectively enriched into the injured kidney, eliminates various ROS (reactive oxygen species) and relieves oxidative stress by utilizing unique redox cycle between Ce < 3 + > and Ce < 4 + > states, and has a good effect in treating acute kidney injury induced by rhabdomyolysis and / or cis-platinum. The research lays a foundation for the metal polyphenol nano material in the treatment of acute kidney injury.

The invention relates to the field of membrane materials, and discloses an epoxy modified starch-based degradable membrane and a preparation method thereof, the epoxy modified starch-based degradable membrane comprises epoxidized starch, modified nanocellulose and a plasticizer; the modified nano cellulose is prepared by mixing a modified composite filler, a nano cellulose dispersion liquid and a zinc acetate dihydrate aqueous solution; the nano-cellulose dispersion liquid is prepared by adhering polytannic acid formed by oxidation and self-polymerization of tannic acid to the surface of nano-cellulose; the modified composite filler is prepared by performing carboxylation modification on nano titanium dioxide coated fumed silica nanoparticles by using succinic anhydride and gamma-aminopropyltriethoxysilane, then reacting with polyethyleneimine to obtain an aminated composite filler, and finally grafting glycidyl dodecyl dimethyl ammonium chloride to the surface of the aminated composite filler. The prepared film material is high in tensile strength, has certain hydrophobicity, and has good heat resistance, antibacterial property and flame retardant property.

The invention discloses a preparation method of injectable nano composite hydrogel for relieving osteoarthritis, which comprises the following steps: firstly, synthesizing nano rod-like hydroxyapatite with the length of 150-300 nm and the diameter of 10-15 nm, and the hydroxyapatite is hydrophilic hydroxyapatite doped with strontium and europium ions; the preparation method comprises the following steps: by taking Ca (NO3) 2, Sr (NO3) 2, Eu (NO3) 3 and soluble phosphate as main raw materials, carrying out hydrothermal reaction to prepare strontium and europium ion co-doped hydrophobic hydroxyapatite, dispersing the strontium and europium ion co-doped hydrophobic hydroxyapatite in a Tris-HCl buffer solution, adding tannic acid, stirring, centrifugally collecting precipitate, and drying to obtain strontium and europium ion doped hydrophilic hydroxyapatite; the preparation method comprises the following steps: taking chondroitin sulfate and adipic dihydrazide as main raw materials, stirring, dialyzing, freeze-drying, and dissolving in a buffer solution to obtain the chondroitin sulfate solution grafted with the hydrazide group; the preparation method comprises the following steps: taking hyaluronic acid, 3-aminophenylboronic acid and sodium periodate as main raw materials, stirring, dialyzing, freeze-drying, and dissolving in a buffer solution to obtain the phenylboronic acid group grafted oxidized hyaluronic acid solution; the preparation method comprises the following steps: blending hydrophilic hydroxyapatite doped with strontium and europium ions, a chondroitin sulfate solution grafted with a hydrazide group, an oxidized hyaluronic acid solution grafted with a phenylboronic acid group and a recombinant collagen solution, and stirring to obtain the injectable nano composite hydrogel. The injectable nano composite hydrogel obtained by the invention has good biocompatibility, and a favorable local immune microenvironment can be created to immunomodulate macrophages so as to relieve osteoarthritis and promote subchondral bone repair.

The invention provides a hemostatic composition, a preparation method thereof and a hemostatic product. The hemostatic composition is prepared from the following raw material components in parts by mass: 0.01 to 0.5 part of cannabidiol, 10 to 150 parts of tannic acid modified carboxymethyl chitosan and 5 to 250 parts of crosslinked starch. The tannic acid modified carboxymethyl chitosan is prepared from the following raw material components in parts by mass: 45 to 55 parts of carboxymethyl chitosan and 0.5 to 1.5 parts of tannic acid. The cross-linked starch is prepared from the following raw materials in parts by mass: 95 to 105 parts of carboxymethyl enzymolysis starch and 2 to 5 parts of sodium trimetaphosphate. The hemostatic composition has a good hemostatic effect, and when the hemostatic composition is used in hemostatic products, the hemostatic products can have a good hemostatic effect.

The invention provides a bio-based adhesive and a preparation method thereof. Inspired by a spider thread structure, biomass adhesive interface enhancement based on a tannic acid adhesion group is combined with construction of a differential phase separation structure by biomass-induced polylipoic acid depolymerization, and a brand new strategy of adhesion-cohesion synergistic enhancement of the adhesive strength of the adhesive is realized. According to the invention, tannic acid and carboxymethyl chitosan are introduced into a lipoic acid-based adhesive, so that the purpose of synergistically enhancing the bonding performance of the adhesive through adhesion-cohesion is achieved, and the defects of weak cohesion, low bonding strength, poor water resistance, poor moisture resistance and the like of the conventional biomass adhesive are overcome. Benefited from a new strategy of adhesion-cohesion synergistic enhancement, the biomass adhesive has good adhesive strength in various environments and materials. In addition, the biomass adhesive also has the characteristics of biological safety, antibacterial and mildew-proof properties and recoverability, so that the product has wider application and potential compared with the previous product, and has a good application prospect.

The invention provides an atomizing agent containing stem cell exosomes as well as a preparation method and application of the atomizing agent, and belongs to the technical field of exosomes. Ferroferric oxide magnetic particles are prepared, the surfaces of the ferroferric oxide magnetic particles are modified through tannic acid, berberine and adriamycin are loaded, then the ferroferric oxide magnetic particles and the exosome secreted by adipose-derived mesenchymal stem cells are mixed, incubated and centrifuged, the mixture is added into normal saline, uniform ultrasonic dispersion is conducted, and the atomizing agent containing the stem cell exosome is prepared. The prepared atomizing agent containing the stem cell exosome is simple in preparation method and wide in raw material source, the prepared atomizing agent directly enters the lung through spray administration, the unique performance of magnetic targeting drug delivery is achieved, drugs are released in a targeted and fixed-point mode, the drug effect is improved, and the effects of efficiently promoting tumor cell apoptosis and resisting lung cancer and pneumonia are achieved.

The invention discloses preparation and application of bionic cerium-based polyphenol nano-enzyme for treating rheumatoid arthritis, and belongs to the field of medical preparations. The method comprises the following steps: respectively complexing cerium ions and tannic acid or epicatechin gallate to prepare cerium-based polyphenol nano-enzyme, and then preparing the cerium-based polyphenol nano-enzyme wrapped by a macrophage membrane. And loading the cerium-based polyphenol nano-enzyme wrapped by the macrophage membrane into the hydrogel to prepare the hyaluronic acid-based hydrogel. The cerium-based polyphenol nano-enzyme and the hyaluronic acid-based hydrogel are characterized, it is verified that the cerium-based polyphenol nano-enzyme and the hyaluronic acid-based hydrogel are successfully synthesized, the particle size of CeTA is about 22 nm, the particle size of M-CeTA is increased to 273 nm, the particle size of CeECG is about 95 nm, and the particle size of M-CeECG is increased to 292 nm. In-vitro experiments prove that the M-CeTA and the M-CeECG do not show obvious cytotoxicity when being less than 80 mu g / mL, and have an obvious inhibition effect on expression of cell inflammatory factors on inflammatory cells.

The invention relates to the technical field of packaging materials, and discloses an antibacterial functional food packaging film and a preparation method thereof.The packaging film is formed by taking low-density polyethylene as a main raw material, adding a compatilizer, a synergistic antibacterial agent, a fiber coating material and the like and carrying out blending, extrusion and film blowing processes. The synergistic antibacterial component is nano-zinc oxide with the surface grafted with biomass antibacterial agent tannic acid, after being immobilized on the surface of the nano-zinc oxide, the tannic acid cannot be easily volatilized and migrated, the broad-spectrum antibacterial performance of the tannic acid is continuously exerted, and the tannic acid and the photocatalytic antibacterial effect of the nano-zinc oxide are mutually cooperated, so that the synergistic antibacterial effect is achieved. Due to the addition of the fiber coating material, the density of the polyethylene film can be improved, and the air tightness and the high-temperature-resistant effect can be improved. In addition, the fiber coating material can exert stress load transfer and absorption effects, so that the prepared polyethylene film has excellent mechanical strength.

The invention discloses a film coating agent for accelerating stabilization of a weathering resistant steel rust layer in a severe atmospheric environment. The film coating agent comprises a film-forming agent and a spraying agent, the film-forming agent comprises a gel agent and a transforming agent; the gel is prepared from one or more of tannic acid, carbomer, chitosan and gelatin; the transforming agent comprises one or more of magnesium sulfate, zinc sulfate and sodium molybdate; the spraying agent comprises an accelerant and an aggressive agent; the accelerant comprises one or more of sodium sulfate, potassium sulfate and chromium sulfate; the aggressive agent comprises one or more of sodium chloride, aluminum chloride and sodium fluoride. The film coating agent provided by the invention can form a stable and uniform rust layer on the surface of the weathering resistant steel, so that the corrosion resistance of the weathering resistant steel is improved.

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 provides an antibacterial synergy-mineralization regulation difunctional nano material as well as a preparation method and application thereof, and belongs to the technical field of biomedical materials. The preparation method comprises the following steps: mixing a disodium hydrogen phosphate solution and a calcium chloride solution to obtain an amorphous calcium phosphate suspension; mixing the amorphous calcium phosphate suspension with a tannic acid solution to obtain an ACP-TA suspension; and finally, mixing the ACP (at) TA suspension and the hydroxypropyl trimethyl ammonium chloride chitosan solution to obtain the bifunctional nano material. A cross-linked shell is formed through the electrostatic adsorption effect of tannic acid and hydroxypropyl trimethyl ammonium chloride chitosan of the antibacterial layer, amorphous calcium phosphate is effectively wrapped, the crystallization process of amorphous calcium phosphate can be remarkably delayed, long-acting release of calcium and phosphorus ions is ensured, the antibacterial function can be effectively achieved, and the service life of the coating is prolonged. An ideal local microenvironment is provided for remineralization of tooth hard tissue, and finally biomimetic mineralization of enamel and deep mineralization plugging of dentinal tubules are achieved.

The invention provides a long-acting rust converting agent for metal surfaces, and relates to the technical field of marine metal surface rust prevention and conversion, tannic acid, gallic acid and salicylic acid are matched with each other and can form a firm complex layer with formed metal oxide or metal through chelation, and the metal surface rust conversion effect is improved. The synergistic effect of the tannic acid corrosion inhibitor, the gallic acid corrosion inhibitor and the salicylic acid corrosion inhibitor enhances the exertion of the synergistic migration protection effect, a relatively compact and smooth conversion film can be formed on the rusted metal surface, the formed conversion film can effectively prevent a corrosion medium from permeating into the metal surface to make contact with the metal, and the metal corrosion inhibitor is suitable for steel structures, especially suitable for steel structure connecting parts and has good corrosion resistance and corrosion resistance. The rust remover has the advantages that the rust remover is good in permeability and high in rust conversion efficiency, harmful rust can be converted into a protective layer beneficial to corrosion prevention, effective protection is provided for a metal matrix, the corrosion prevention effect can reach 20 years or above, frequent maintenance is omitted, resources, manpower and material resources are saved, and remarkable economic benefits are achieved.

The invention provides a green and efficient petroleum passivator and a preparation method thereof, and belongs to the technical field of passivators. Carboxymethyl chitosan, phytic acid and beta-cyclodextrin are coupled to prepare a chitosan-phytic acid-cyclodextrin compound, bismuth, lanthanum, cerium and aluminum are compounded, and the green and efficient petroleum passivator is prepared through tannic acid polymerization modification. The prepared green and efficient petroleum passivator is green, safe, non-toxic and efficient, has good capturing and passivating capacity on ions such as iron, nickel and vanadium, greatly improves the activity of a catalyst, prolongs the service life of the catalyst, and has wide application prospects.

The invention belongs to the technical field of biological medicines, and particularly relates to hydrogel with photo-thermal multiple antibacterial and hemostatic functions. The multifunctional hydrogel is prepared from epsilon-polylysine (EPL), gallic acid (GA), tannic acid (TA) and ferric trichloride hexahydrate. The polyphenols are obtained through multiple mechanisms such as reaction between the polyphenols and amino groups, metal chelation, pi-pi interaction and electrostatic attraction (as shown in Figure 1). The metal ion and multiple dynamic cross-linking system hydrogel is constructed, the hydrogel with positive charges enriched on the surface can act with blood platelets with negative charges, red blood cell aggregation, blood platelet adhesion and vasoconstriction effects are promoted, and the blood coagulation efficiency is improved. The hydrogel shows excellent antibacterial performance and photo-thermal performance, can prevent infection in the inflammation stage of wound healing, can effectively accelerate wound healing, and has good biological safety.

The invention relates to the technical field of cutter manufacturing, in particular to a high-strength and high-toughness ceramic cutter and a preparation method thereof. The metal ions are loaded on the boron nitride nanosheets, the agglomeration phenomenon of the boron nitride nanosheets can be improved through loading of the metal ions, the interaction force between the boron nitride nanosheets is enhanced, and therefore the mechanical strength of boron nitride is improved. According to the preparation method disclosed by the invention, a complex with adhesion is formed on a boron nitride nanosheet by utilizing the chelation of tannic acid and iron ions, and boron nitride loaded with the iron ions and modified hydrotalcite are adhered together by utilizing the adhesion of the complex. The prepared modified soybean protein has a large number of amino groups, the boron nitride-hydrotalcite compound with the amino groups has better compatibility with a modified soybean protein binder, the dispersity of the boron nitride-hydrotalcite compound in a matrix is improved, and the strength and toughness of the ceramic cutting tool are improved.

The invention discloses a low-smoke flame-retardant cable outer layer material, and a preparation method of key components and a high-entropy alloy nano material comprises the following steps: grinding cerous nitrate, ferric nitrate, manganous nitrate, sodium hexahydroxyplatinate and copper nitrate into particles according to a ratio of 2: 1: 1: 1: 1; then adding 10-20 times by mass of a 32% tannic acid solution and 5-8 times by mass of a 10% glutaraldehyde solution, carrying out an oil bath at 65-70 DEG C for a reaction for 4-8 h, then carrying out overnight vacuum freeze drying to obtain mixed powder, placing the mixed powder in a crucible of a muffle furnace, then calcining the mixed powder at 1000-1200 DEG C under the protection of nitrogen flow for 4-10 h, and finally cooling the calcined mixed powder to room temperature. And cooling. The prepared outer layer material for the cable overcomes the defects that a conventional cable easily releases a large amount of toxic smoke during combustion, is poor in flame retardant property and contains halogen to pollute the environment.

The invention discloses a radiation refrigeration coating and a preparation method thereof. The radiation refrigeration coating comprises a first filler and a second filler, the mass ratio of the first filler to the second filler is (1-3): (1-5), and the first filler comprises the following components in percentage by weight: 50-70% of a polyurethane emulsion, 10-15% of a silane coupling agent, 8-10% of multi-mesoporous nano-silica and 5-8% of talcum powder; the second filler comprises the following components in percentage by weight: 60%-70% of polyethylene glycol, 10%-15% of a dispersing agent and 5%-8% of nano barium oxide; 5%-8% of tannic acid; 3%-5% of nano silver; the viscosity of the polyurethane emulsion ranges from 300 cps to 800 cps. The radiation refrigeration coating disclosed by the invention has the advantages that a refrigeration film has larger infrared radiation refrigeration capacity in an atmospheric window, better ultraviolet light absorption capacity and long service life.

The invention relates to the technical field of pharmaceutical preparations, and particularly discloses a synthetic nicotine composition and a preparation method thereof. The nicotine buccal film agent disclosed by the invention is prepared from the following components in parts by weight: 2 to 4 parts of nicotine clathrate compound powder, 0.2 to 0.6 part of phosphatidic acid, 0.1 to 0.3 part of tannic acid, 0.1 to 0.2 part of sodium ascorbate, 0.04 to 0.06 part of tocopherol, 0.01 to 0.02 part of ethylene diamine tetraacetic acid, 2 to 4 parts of povidone and 40 to 80 parts of absolute ethyl alcohol. The synthesized nicotine composition prepared by the invention can effectively relieve the phenomenon that the faster the nicotine is released, the stronger the bitter taste is. Meanwhile, in a high-temperature and high-humidity environment, the stability of nicotine can be effectively maintained, and the oxidation half-life period of nicotine is prolonged.

The invention discloses a high-ground-temperature-resistant ultrahigh-flow nano-modified polymer grouting material as well as a preparation method and application of the high-ground-temperature-resistant ultrahigh-flow nano-modified polymer grouting material, and belongs to the technical field of geotechnical engineering. According to the present invention, the nanometer modified cementation particles are combined with the calcium hydroxide, the sodium carbonate, the cellulose nanofiber and the tannic acid to regulate and control the hydration process, the fluidity and the mechanical strength, the nanometer modified cementation particles are injected into the deep surrounding rock, the high fluidity can be maintained in the high ground temperature environment for a long time, the grouting diffusion range is effectively expanded, and the accurate regulation and control of the grouting material gelling time can be achieved. Meanwhile, high-mass-fraction fly ash and silica fume are excited to generate calcium aluminosilicate hydration products, and the problems that an existing conventional calcium silicate grouting cementing material is poor in reinforcing and anti-seepage effect in a high-ground-temperature environment, slurry is prone to cracking and the like are solved.

The invention relates to nanoparticle-loaded antibacterial composite hydrogel as well as a preparation method and application thereof, a hydrogel network main body is formed by grafting phenylboronic acid to methacrylated I-type collagen rCol1MA-PBA and methacrylated polylysine EPLMA and adding glucose oxidase GoX for crosslinking, and is loaded with core-shell nano-enzyme C (at) Z (at) T at the same time, and the core-shell nano-enzyme C (at) Z (at) T is loaded with the core-shell nano-enzyme C (at) Z (at) T and the core-shell nano-enzyme C (at) Z (at) T; the core-shell nano-enzyme C (at) Z (at) T is composed of a spherical CeO2 nano-particle core, a zeolite imidazate framework material TIF-8 shell and tannic acid TA coating the shell. The raw materials of the hydrogel are easy to obtain, the preparation method is simple, the price is low, and the components are safe and reliable; in addition, multiple functions of resisting bacteria, resisting inflammation, resisting oxidation, promoting angiogenesis and the like are integrated, a more comprehensive treatment effect is provided, and the dressing can be used for healing the wound surface of diabetes mellitus.

The invention discloses a tannic acid modified lignin phenolic resin antibacterial adhesive and a preparation method thereof, and belongs to the technical field of bio-based adhesives. Alkali lignin is used as a raw material to prepare lignin nano-particles, then ferric trichloride and tannic acid are used for modifying the lignin nano-particles, and the tannic acid modified lignin phenolic resin antibacterial adhesive is prepared. Gallotannic acid / iron complexed lignin nano-particles are obtained, the gallotannic acid / iron complexed lignin nano-particles, phenol, formaldehyde and alkali liquor are mixed, and the lignin phenolic resin adhesive is prepared through an addition condensation reaction. The lignin phenolic resin adhesive prepared by the invention can realize high-proportion phenol substitution, has a good photo-thermal antibacterial effect, and provides a new way for development of an antibacterial environment-friendly adhesive.

The invention discloses a method for preparing recombinant collagen antioxidant microspheres without a cross-linking agent. The method comprises the following steps: 1, dissolving recombinant collagen and chitosan in deionized water containing glacial acetic acid to serve as a water phase; petroleum ether containing a surfactant is used as an oil phase; 2, injecting the oil phase into the water phase, emulsifying and stirring through a homogenizer, and reducing the temperature of the system to obtain an emulsion; 3, a fixing agent, water and absolute ethyl alcohol are blended and precooled, and fixing liquid is obtained; 4, adding the stationary liquid into the emulsified liquid for curing, and washing the cured microspheres; and 5, transferring into a tannic acid aqueous solution to soak, then washing with deionized water, and freeze-drying to obtain the recombinant collagen microspheres with uniform size. The recombinant collagen microspheres prepared by the method have good dispersity and uniform and controllable size, avoid the toxicity problem of a cross-linking agent, can be applied to the fields of medical instruments, tissue engineering, drug delivery and the like as a filling agent, and have wide commercial application prospects.

The invention discloses a photocatalyst antibacterial hydrogel-based fresh-keeping material as well as a preparation method and application thereof, and belongs to the technical field of fresh-keeping materials. The photocatalyst antibacterial hydrogel-based fresh-keeping material is prepared from the following raw materials in parts by mass: 180 to 220 parts of water, 1 to 6 parts of graphite-phase carbon nitride, 10 to 20 parts of polyvinyl alcohol, 1 to 3 parts of carboxymethyl chitosan and 8 to 12 parts of tannic acid. The invention further discloses a preparation method of the photocatalyst antibacterial hydrogel-based fresh-keeping material and application of the photocatalyst antibacterial hydrogel-based fresh-keeping material in fruit fresh keeping. The photocatalyst antibacterial hydrogel-based fresh-keeping material disclosed by the invention solves the problems of potential toxicity, easiness in inactivation, poor fresh-keeping effect and poorer mechanical property of an existing fresh-keeping material, realizes long-time effective fresh keeping of high-moisture fruits, does not involve chemical reaction in the preparation process, is non-toxic, easily available and degradable in raw materials, and has excellent environmental friendliness.

The invention discloses a rapid hemostasis powder material for massive hemorrhage. The rapid hemostasis powder material for massive hemorrhage is tannic acid modified carboxymethyl chitosan. The invention also provides a preparation method and application of the rapid hemostasis powder material for massive hemorrhage, and a rapid hemostasis microgel composition containing the rapid hemostasis powder material for massive hemorrhage. The rapid hemostasis powder material and microgel composition for massive hemorrhage have excellent water solubility, hemostasis performance and biocompatibility, have multiple effects of sterilization, anti-inflammation, wound healing promotion and the like, and are beneficial to rapid healing of wound parts after hemostasis.

The invention belongs to the technical field of agricultural waste resource utilization, and particularly relates to a method for efficiently synthesizing medium-chain fatty acid through dry-wet coupling anaerobic fermentation. The invention provides a method for efficiently synthesizing medium-chain fatty acid through dry-wet coupling anaerobic fermentation, which comprises the following steps: spatially isolating hydrolytic acidification microorganisms and carbon chain extension microorganisms through partition of a fermentation device, innovatively adopting chitosan and tannic acid as an adhesive, and immobilizing hydrolytic acidification bacteria and lactic acid producing bacteria on agricultural wastes. Efficient hydrolytic acidification of agricultural wastes is realized, lactic acid and acetic acid are directionally produced, and a high-quality substrate is provided for a carbon chain extension stage. And in addition, the medium-chain fatty acid is synthesized by innovatively spraying the biogas slurry containing potassium ferrate and spraying the acidified product generated in the hydrolytic acidification area to the carbon chain extension area, and meanwhile, the potassium ferrate promotes interspecific electron transfer of the system, so that the carbon chain extension reaction is further enhanced, the fermentation time is shortened, and the medium-chain fatty acid is efficiently synthesized.

The invention relates to a high-barrier antibacterial polylactic acid packaging material and a preparation method thereof, and belongs to the technical field of biodegradable packaging materials. The technical problems that a traditional polylactic acid material is insufficient in barrier property, poor in antibacterial performance and difficult to meet the packaging requirements of livestock and poultry meat, food and medicine are solved. A graphene oxide lamellar material is subjected to copper ion functionalization treatment and is bridged with tannic acid molecules through copper ions to form a nano filler, and then the filler is blended with a plasticized polylactic acid solution to prepare the membrane. The preparation method comprises the following steps: preparing a copper ion functionalized dispersion liquid from graphene oxide and copper nitrate, self-assembling the copper ion functionalized dispersion liquid and tannic acid under the condition that the pH is 8-10 to generate a nanofiller, uniformly dispersing the nanofiller, mixing the nanofiller with polylactic acid, polyethylene glycol and glycerol according to a specific mass ratio, coating to form a film, and controlling solvent volatilization conditions to obtain the high-performance packaging material. According to the method, the oxygen barrier property and the antibacterial activity of the material are remarkably improved through uniform dispersion of the nanofiller and reinforcement of a coordination network. The obtained material is suitable for packaging foods such as livestock and poultry meat.

The invention provides a self-repairing hydrated salt phase change microcapsule as well as a preparation method and application thereof, and belongs to the field of phase change materials. The preparation method comprises the following steps: preparing a hydrated salt phase change material and sorbitol into eutectic melt by adopting a melting method; strontium carbonate, sorbitol grafted nano titanium dioxide, SiO2-coated silicone rubber microspheres, hollow Al2O3 microspheres, tannic acid microcapsules, alpha-zirconium phosphate, melamine polyphosphate, diethyl aluminum hypophosphite, carboxylated multi-walled carbon nanotubes, polydopamine modified boron nitride nanosheets and hydrophilic fumed silica are added into the eutectic melt, and blending is performed to obtain a core material; The preparation method comprises the following steps: adding strontium carbonate, sorbitol grafted nano titanium dioxide, SiO2-coated silicone rubber microspheres, hollow Al2O3 microspheres, tannic acid microcapsules, alpha-zirconium phosphate, melamine polyphosphate, diethyl aluminum hypophosphite, carboxylated multi-walled carbon nanotubes, polydopamine modified boron nitride nanosheets and hydrophilic fumed silica into the eutectic melt; bio-based polyurethane-polyurea is used as a shell material, the core material is coated in the shell to prepare the microcapsule, and the temperature of the coating operation is not higher than the phase change temperature of the hydrated salt phase change material; the surface is coated with a super-hydrophobic coating. According to the invention, a solid filler system is constructed, and a low-temperature preparation process is combined, so that the phase-change microcapsule with high performance, high reliability and high safety is developed.

The invention discloses a small tower footing alkali polishing additive suitable for high back contact of a TOPCon battery and a use method of the small tower footing alkali polishing additive, and relates to the technical field of monocrystalline silicon polishing. Comprising the following components: a corrosion catalyst, a multi-carboxyl polymer, a high-wetting defoaming agent, a surfactant, a chelating agent, a protective agent, hyperbranched polylysine, tannic acid, quinoline yellow, caffeine, 3-(N-morpholinyl)-2-sodium hydroxypropanesulfonate and deionized water. The alkali polishing additive is good in polishing effect under the condition of low weight loss, a relatively rough small-size tower footing can be formed on the back face of a silicon wafer after alkali polishing, and the cell conversion efficiency is gained.