81 results about "Starch solution" patented technology

The invention discloses a high-strength water-resistant starch adhesive and a preparation method thereof, and belongs to the technical field of preparation of environment-friendly adhesives. The problems of strength and mildew resistance of the starch adhesive are solved. The preparation method comprises the following steps: preparing 5-10g of polyethyleneimine into a 30-60wt% solution, weighing a certain mass of urea according to a molar ratio of (1-5): 1, adding the weighed urea into the prepared polyethyleneimine solution, and reacting for 8-14 hours in an oil bath to obtain a first branched polymer; 20-50 g of dialdehyde starch and 60-90 g of polyvinyl alcohol are added into a flask to prepare a starch solution, then the reaction temperature is set, uniform stirring is performed for gelatinization treatment, a second gelatinized solution is obtained, and after mixing reaction, a prefabricated high-strength water-resistant starch adhesive is obtained; and adding 5-10 g of cassava starch filler and 5-10 g of polymethyl silicon polyphenyl isocyanate, and stirring for 10-30 minutes to obtain the high-strength water-resistant starch adhesive.

The application discloses a kind of metal-loaded starch aerogel and its preparation method and application, comprising the following steps: (1) starch and water are prepared into starch milk, starch milk is heated, and gelatinized starch solution is obtained;(2) sodium laurate is added to the gelatinized starch solution and heated to react, and after the reaction is completed, starch-sodium laurate complex solution is obtained;(3) metal nitrate solution is added to the above-mentioned complex solution, and after stirring uniformly, a reducing agent is added to reduce metal ions, and metal-loaded starch hydrogel is obtained;(4) the above-mentioned hydrogel is pre-frozen and freeze-dried to obtain metal-loaded starch aerogel.The metal-loaded starch aerogel of the application has excellent ethylene adsorption capacity, with an adsorption capacity of about 32 mL / g, good adsorption stability, and the adsorption process can be carried out at normal temperature and pressure, which can be used for fruit preservation.

The invention discloses a collagen membrane as well as a preparation method and application thereof, and belongs to the field of cosmetics. The preparation method of the collagen membrane comprises the following steps: pickling cow leather with lime, washing the pickled cow leather with water, then acidifying the cow leather with hydrochloric acid, washing the acidified cow leather with water, and washing away interfibrous substances until the hardness of the cow leather is 1t; the mmol / g is 0.1 to 0.3 mmol / 100g; cutting the obtained cow leather into particles, rolling the particles by a defibrator to obtain collagenous fibers, then adding a gelatinized acetate starch solution and a gelatinized chitosan solution into the collagenous fibers, and uniformly mixing and kneading to obtain collagenous fiber slurry with the water content of 95-97%; and casting the obtained collagen fiber slurry into a membrane, drying at 50-55 DEG C for 2-4 hours, soaking the membrane in a mixed solution of baking soda and glutamine transaminase for 2-3 seconds, drying at 50-55 DEG C, flushing by adopting a sodium thiosulfate solution, and washing to remove salt, thereby obtaining the collagen membrane. According to the preparation method, crosslinking among collagenous fibers is enhanced, and the structural stability of the membrane is improved.

The invention discloses a method for improving the moisture infiltration capacity of urban green land soil. The method comprises the following steps that S1, according to design requirements, a foundation is excavated, earthwork is cleaned, the foundation is leveled and divided in a checkerboard mode, and an air pump device is used for aerating the foundation in checkerboard checks; s2, crushing the construction waste: crushing the engineering muck, the engineering slurry, the engineering waste, the demolition waste and the decoration waste into coarse grains with the grain size of 30-50mm, removing metal in the coarse grains, paving the coarse grains on a foundation, and leveling and compacting to form a permeable layer; s3, a starch solution is injected into the permeable layer, glucose is formed after the starch solution is hydrolyzed in the permeable layer, acetic acid is formed after the glucose is alcoholized, hydroformylated and acidified, and the acetic acid reacts with carbonate in the permeable layer to generate water-soluble substances which are consumed, so that the porosity of the permeable layer is improved. The problem that urban inland inundation is prone to occurring due to the fact that urban green land permeability is poor can be solved.

The invention relates to agricultural production, in particular to a method for evaluating technologies for treating fibrous cotton seeds against disease, and can also be used to create methods for evaluating technologies for treating seeds of other agricultural plants. The essence of the invention is that in the method of assessing the resistance of cotton plants to disease, which consists in cultivating seed materials in an area artificially infected with the pathogen and isolated with polyethylene coating, fibrous cotton plants, on whose outer surfaces a thin coating is created by sequentially applying starch and fungicide and / or fungicide and starch solutions, are cultivated in an artificially infected area.

The invention provides a fully degradable nanocellulose composite liquid mulching film and a preparation method thereof, and the preparation method comprises the following steps: adding hexadecyl trimethoxysilane into a nanocellulose solution, mixing and heating to obtain a hydrophobically modified cellulose solution; adding citric acid and sodium hypophosphite into the starch solution, mixing and heating for esterification reaction to obtain an esterification product, and adding deionized water after the esterification product is cooled to room temperature to obtain a product solution; mixing and stirring a gelatin solution and a dopamine solution to obtain a modified gelatin solution modified by polydopamine; mixing the modified gelatin solution with the product solution to obtain composite gel; mixing, shearing and emulsifying the modified cellulose solution, the composite gel, an emulsifier, a plasticizer and a water-retaining agent to obtain a composite emulsion; alkali liquor is dropped into the composite emulsion to adjust the pH value, then a cross-linking agent is added, and the composite liquid mulching film is obtained after mixing and heating.

The invention belongs to the field of microbial preparations, and particularly relates to a protection method of a microzyme freeze-dried fungicide based on low-liquefied starch. On one hand, the invention provides a freeze-drying protective agent. The freeze-drying protective agent is obtained by carrying out enzymolysis on a starch solution with amylase for 20-200 minutes, centrifuging and freeze-drying. On one hand, the invention provides a protection method of a saccharomycetes freeze-drying bacterial agent, which comprises the following steps: adding the freeze-drying protective agent into saccharomycetes resuspended thalli, standing, removing supernatant to obtain paste, and freeze-drying the paste. By using the freeze-dried microbial inoculum provided by the invention, the survival rate of the saccharomycetes freeze-dried microbial inoculum is remarkably improved.

The application discloses modified emulsified starch and a preparation method thereof and application of the modified emulsified starch to health products for the elderly, and relates to the technical field of starch modification. The preparation method of the modified emulsified starch comprises the following steps: high-temperature liquefaction is performed on starch milk to obtain a liquefied starch solution; the pH of the liquefied starch solution is adjusted, starch amylase is added to perform an enzymolysis reaction, then the residual starch amylase is inactivated to obtain an enzymolysis product; the pH of the enzymolysis product is adjusted, octenyl succinic anhydride is added to perform an esterification reaction, and an esterification modified solution is obtained; and the esterification modified solution is washed and spray-dried to obtain the modified emulsified starch. The modified emulsified starch has a high coating rate for vitamin C, can prevent photo-oxidation of vitamin C, has a good dissolution effect, and is convenient for the elderly to absorb and utilize vitamin C.

The application discloses a preparation method of starch-unsaturated fatty acid compound. The method comprises the following steps: starch is pretreated by a debranching enzyme to obtain a debranched starch solution, the debranched starch solution is mixed with unsaturated fatty acid, an ethanol-water solution is added as a ball milling medium, a multi-stage ball milling parameter dynamic regulation process is adopted, and low-temperature protection, medium-temperature complexing and cooling solidification stage ball milling reactions are sequentially carried out, and finally, drying, crushing and sieving are performed to obtain the starch-unsaturated fatty acid compound. Through the synergistic effect of debranching enzyme pretreatment and multi-stage ball milling, the starch and the unsaturated fatty acid are efficiently compounded under mild conditions. The obtained compound has high compounding rate, high resistant starch content and excellent antioxidant stability. The compound can be used as a low-glycemic index functional food raw material and is used for preparing blood glucose management, weight control or antioxidant functional food. The method is mild, controllable and reproducible, does not need high temperature and high pressure, and meets the clean label consumption trend.

The application provides a wet starch preparation and automatic adding system, which comprises a clean water tank, a starch preparation tank, a quantitative adding system, a ton bag hoisting system and a control system, wherein the water outlet of the clean water tank is connected with the water inlet of a starch water inlet pump through a first pipeline; the water inlet of the starch preparation tank is connected with the water outlet of the starch water inlet pump through a second pipeline; the quantitative adding system is used for adding starch into the starch preparation tank; the ton bag hoisting system is arranged above the quantitative adding system and is used for hoisting and conveying a ton bag of starch to add the starch into the quantitative adding system; the water inlet of a starch water outlet pump is connected with the starch solution outlet of the starch preparation tank; the water outlet of the starch water outlet pump is connected with the starch solution inlet of a mixing machine through a starch solution conveying pipe; and the control system is electrically connected with the starch water inlet pump, the quantitative adding system, the ton bag hoisting system and the starch water outlet pump respectively. The system can effectively realize wet addition of the starch in the process of the gypsum board production, stabilize the production and improve the product quality.

This application relates to the field of papermaking technology, and more particularly to a cationic cassava starch and its preparation method, apparatus, and application. The preparation method involves repeatedly statically mixing 60%–69% etherifying agent with 5%–15% caustic soda solution, adding 35%–42% cassava starch solution within 10–30 seconds, mixing, sieving, and then undergoing an etherification reaction to obtain cationic cassava starch. The apparatus includes an etherifying agent storage unit, a caustic soda solution storage unit, a raw material mixing unit, a cassava starch solution supply unit, a mixing and sieving unit, a reaction unit, controllable valves, a timer, and a control unit. Two storage units are connected to the raw material mixing unit, which is connected to the mixing and sieving unit via valves. The starch solution supply unit is also connected to it, and subsequently to the reaction unit. The control unit regulates the opening and closing of the valves to ensure the mixing of the solution is completed within 10–30 seconds. The application is the use of cationic cassava starch in papermaking. It is evident that the preparation method of this application can avoid gelatinization caused by excessively high local concentration when starch is mixed with alkali solution, and reduce the generation of impurities; the wet process can flexibly control the degree of substitution to adapt to paper machine production, eliminate the drying process, and produce wet cationic tapioca starch with stable degree of substitution, excellent quality, which can be directly supplied to paper machines and has good retention and filtration effects.

The invention discloses a wood fiber-based composite material with a tough interface structure and a preparation method thereof, and the preparation method comprises the following steps: 1) mixing a gelatinized starch solution and a waterborne polyurethane emulsion to form a dynamically stable flow equalizing agent; 2) adding the wood fiber and the coconut shred fiber into hydrogen bond alkalinity beta gt; carrying out colloid milling in 0.5 of a solvent to obtain mixed fibers; and (3) uniformly mixing the flow equalizing agent obtained in the step (1) and the mixed fiber obtained in the step (2) by using a kneading machine, putting the mixture into a mold, and carrying out hot press molding to obtain the composite material. The starch solution and the waterborne polyurethane are prepared and compounded to form the flow equalizing agent, the flow equalizing agent is mixed with the pretreated fibers, and the binding material with high strength and high toughness is prepared through kneading and mold forming. The adhesive combines the adhesion of natural starch and the flexibility of waterborne polyurethane, realizes multi-component synergistic enhancement, and has excellent mechanical properties and environmental protection characteristics.

The invention belongs to the technical field of glass fiber surface treating agents, and discloses a preparation method of a konjac glucomannan modified pea starch glass fiber impregnating compound, which comprises the following steps: adding water into pea starch, and gelatinizing at 85 DEG C for 30 minutes to prepare a pea starch solution; the preparation method comprises the following steps: adding water into konjac glucomannan, and stirring and dissolving at 60 DEG C to prepare a konjac glucomannan solution; mixing the pea starch solution and the konjac glucomannan solution according to a mass ratio of 4: 1, adding a silane coupling agent, and carrying out esterification grafting reaction at 75 DEG C for 1 hour to obtain a mixed solution; and adding a plasticizer, a lubricant and an antistatic agent into the mixed solution, and homogenizing at a high speed to obtain the impregnating compound. According to the preparation method, a pea starch and konjac glucomannan full bio-based system is adopted, the impregnating compound is prepared through a water-phase esterification reaction, the process is simple, the reaction condition is mild, a three-dimensional network is formed through esterification crosslinking of konjac glucomannan linear molecules and pea starch branched chains, and the compactness of a film layer is improved.

This utility model relates to the technical field of starch production equipment, and more particularly to a thickener for soluble starch production, comprising a thickening tank, a fixed frame, and a crossbeam. The fixed frame is fixedly installed at the lower end of the thickening tank, and the crossbeam is fixedly installed at the upper end. Guardrails are installed on both sides of the crossbeam, and a base is installed at the lower end of the crossbeam. A liquefying enzyme spray pipe is installed on one side of the thickening tank, and the other side of the liquefying enzyme spray pipe is fixedly installed in the base. With this thickener, the liquefying enzyme spray pipe can evenly spray the liquefying enzyme onto the surface of the starch solution in the thickening tank, ensuring full contact between the liquefying enzyme and the starch, and improving the liquefaction efficiency of the starch. The nozzle is equipped with an atomizing nozzle, allowing the liquefying enzyme to be sprayed in a fine mist, further improving the liquefaction effect. The layout of the annular electric heating tube can evenly heat the starch solution in the thickening tank, improving heating efficiency and effectively preventing heat waste caused by localized overheating or undercooling of the liquid.

The invention relates to the technical field of food preparation, and discloses a crushing device and method for preparing a surface coating material for frying large meatballs, the crushing device comprises a main body assembly, the main body assembly comprises a preparation pool and an isolation plate, the isolation plate is arranged in the preparation pool, and one side of the preparation pool is provided with a feed opening and a material accumulation groove; and the crushing assembly is arranged in the material accumulation groove and comprises a fixed seat fixed in the material accumulation groove, a supporting shell is fixed in the fixed seat, and a rotating shaft is rotationally connected in the supporting shell. By arranging the crushing assembly, meat particles mixed in a starch solution can be effectively crushed and converted into fine minced meat, so that the problem of meat particle waste is solved, the minced meat can be uniformly attached to the surface of the large meatballs in the process of coating the large meatballs with the coating, the layering sense and the flavor of the coating are improved, and the large meatballs are more delicious. The fried large meatballs are more scorched in fragrance and more unique in flavor.

The present disclosure relates to a clean coal for combustion and a preparation method thereof. The preparation method includes the following steps: (1) dispersing starch in water, uniformly stirring, and fully gelatinizing; (2) adding a sulfur-fixing agent into the gelatinization solution, and centrifuging to obtain the starch gelatinized solution containing the sulfur-fixing agent; (3) crushing the coal for combustion to obtain coal particles; and (4) conveying the coal particles to a fluidized bed, spraying the starch gelatinized solution containing the sulfur-fixing agent on the coal particles in a suspension state, and drying to obtain coal particles adsorbed with the sulfur-fixing agent and gelatinized starch. According to the present disclosure, the starch gelatinized solution is used to dissolve the soluble sulfur-fixing agent, and then the starch solution is adsorbed in-situ into the coal particles, so that the soluble sulfur-fixing agent is uniformly adsorbed in the coal for combustion.

Provided are a starch film-forming composition and a preparation method of soft capsules thereof. The starch film-forming composition comprises 25-60 wt% of acid-treated starch, 20-40 wt% of a plasticizer and 15-40 wt% of water, wherein the acid-treated starch has a paste viscosity of 5-196 mPa·s, and the paste viscosity is obtained by preparing a 10% w / w starch solution from the acid-treated starch and water, and the acid-treated starch has a phosphate content of 0.01-0.06% (calculated based on phosphorus P). The soft capsules prepared from the starch film-forming composition have a short drying time and uniform moisture, thereby reducing the production cost of the soft capsules.

The invention belongs to the technical field of starch processing, and particularly relates to a preparation method of jackfruit seed resistant starch based on ultrasonic treatment. Uniformly mixing jack fruit seed starch and plasma activated water to obtain a starch solution; performing ultrasonic treatment on the starch solution, performing gelatinization, then adding gallic acid, performing uniform stirring, performing compounding through a shaking table, performing cooling, performing drying, and performing sieving so as to obtain the jackfruit seed resistant starch. The conditions of the ultrasonic treatment are as follows: the power is 300 to 600 W, the frequency is 40 Hz, and the time is 30 to 60 minutes. The compound with high resistant starch content is prepared by utilizing a synergistic modification method of two physical technologies of ultrasonic wave and plasma activated water. Meanwhile, chemical reagents are not used in the preparation method provided by the invention, and the preparation method can be used in food labeled with clean labels.

This invention discloses a method and application for preparing whey protein isolate microgels based on enzymatic hydrolysis of OSA-modified starch, belonging to the field of emulsion gelation technology. The preparation of the whey protein isolate microgels of this invention includes the following steps: dissolving OSA-modified starch in phosphate buffer, gelatinizing in a boiling water bath, cooling, adding pullulanase for enzymatic hydrolysis, boiling to inactivate the enzyme, then adding β-amylase for secondary enzymatic hydrolysis, centrifuging, collecting the supernatant, and freeze-drying to obtain EOSA starch; preparing whey protein isolate solutions and EOSA starch solutions separately, mixing them at a 1:1 volume ratio, homogenizing, and obtaining the final microgel. The microgel particles have a smooth surface and a uniform gel network structure; they can effectively stabilize the emulsion morphology, exhibiting good storage and thermal stability; furthermore, they are suitable for the preparation of swallowable foods, and the degree of enzymatic hydrolysis of OSA-modified starch can be adjusted to control the swallowability grade, adapting to different swallowability requirements.

The invention discloses silicon dioxide prepared based on a pH oscillation strategy and a method thereof. The method comprises the following steps: S1, preparing a sodium silicate aqueous solution and an acidolysis starch solution; s2, regulating and controlling gel self-assembly according to a pH oscillation strategy; adding the acidolysis starch solution into the sodium silicate solution, and fully stirring and mixing to form a uniform mixed solution; slowly adding an acid solution into the mixed solution, and adjusting the pH value to 2-4; then adding a high-concentration sodium silicate aqueous solution to adjust the pH value to 8-10; adding the acid solution again, and adjusting the pH value to 2-4; s3, aging and washing the gel formed in the step S2; and S4, drying and calcining the washed gel to obtain the high-pore-volume silicon dioxide. According to the invention, the proportion of the silicon source to the biomass template is accurately regulated and controlled, the pH is regulated and controlled to induce the self-assembly of silicon species on the starch template, and the assembly dynamics of the silicon source and the biomass template in the solution is effectively regulated and controlled by adopting a pH oscillation strategy, so that a new way is provided for low-cost and environment-friendly manufacturing of the high-performance porous silicon dioxide material.

The invention discloses a starch-based nanoscale drug loading system and a preparation method thereof, and belongs to the technical field of pharmaceutical preparations. The invention aims to solve the technical problems of nonuniform particle size and morphology of products, potential toxicity caused by use of chemical cross-linking agents, complicated operation, poor universality of a preparation process and the like in the conventional preparation method. According to the key points of the technical scheme, the preparation method of the starch-based nanoscale drug loading system comprises the following steps: starch debranching treatment: adding water into starch to prepare a suspension, gelatinizing the suspension, cooling, and carrying out enzymolysis to obtain a debranched starch solution; adding a medicine: adding an alcohol solution of an alcohol-soluble medicine into the debranched starch solution, and uniformly mixing to obtain a hydrophilic phase; emulsion preparation: mixing the hydrophilic phase with the oil phase, and emulsifying to obtain an emulsion; the oil phase is grease containing a surfactant; and performing freeze drying, centrifugation and separation on the emulsion to obtain the starch-based nano-scale drug loading system.

The invention provides a microbial fertilizer composition for buffering soil acidity and a preparation method thereof, and relates to the technical field of microbial fertilizers. The microbial fertilizer composition is prepared from straw modified biochar, oyster shell powder, a straw fermentation material, microbial composite microspheres and an organic fertilizer, wherein the straw modified biochar is obtained by performing acid treatment on the straw biochar and then mixing the treated straw biochar with a carboxymethyl cellulose-glucoside solution; the microbial composite microspheres are obtained by mixing and fermenting pectin-starch microspheres and lactobacillus mucus fermentation liquor and completely gelatinized starch solution. The soil conditioner overcomes the defects in the prior art, effectively buffers soil acidity for a long time, further improves soil fertility, and promotes high yield of crops.

This invention discloses an ASA paper sizing emulsion, its preparation method, and its application, belonging to the field of papermaking additives. By weight, it comprises the following components: 1.75 parts of 3.5 wt% cationic starch solution; 5.25 parts of 1.5 wt% amphoteric polyacrylamide solution; 0.01 parts surfactant; and 1 part ASA stock solution. The D90 particle size of the sizing emulsion is 0.5-5.0 μm and / or the average particle size is 0.5-3.0 μm. This invention mixes cationic starch and amphoteric PAM in a certain proportion and reacts them under specific conditions to prepare an ASA emulsion mixture. The stability of the prepared emulsion is significantly improved, especially its stability at low temperatures, which is significantly better than that of emulsions emulsified with pure cationic starch emulsifier. Furthermore, the prepared ASA emulsion can be used for different pulp layers, meeting the needs of on-site applications.

Provided in the present application is a preparation method for starch hydrogel microspheres, belonging to the technical field of embolic microsphere manufacturing. The preparation method for starch hydrogel microspheres comprises the following steps: adding a first crosslinking agent to a starch solution and mixing to obtain an aqueous phase solution; adding an oil phase solution to the aqueous phase solution and mixing to obtain a mixed liquid; and adding a second crosslinking agent to the mixed liquid and mixing for reaction to obtain the starch hydrogel microspheres. The starch hydrogel microspheres prepared by the method feature such advantages as long in-vivo degradation time and adjustable degradation time, and can be applied to a wide range of disease types.

The present application belongs to the technical field of agricultural fertilizer, and particularly relates to a preparation method and application of a biochar-based coated fertilizer. The present application is advantageous for nano-iron modification of starch by mixing ferric chloride, ferrous chloride and starch solution; the swelling property and water retention of the coating liquid are improved by mixing the starch-based ferroferric oxide solution and polyvinyl alcohol, and the obtained coating liquid is wrapped outside the fertilizer core, which is advantageous for improving the slow-release property of the biochar-based coated fertilizer. Experimental results show that the swelling property of the prepared coating material is as high as 189.91%; after the coating material is used to prepare the biochar-based coated fertilizer, the 30-day cumulative release rates of nitrogen, phosphorus and potassium are 22.87%, 34.93% and 84.08% respectively, and the water retention of the soil after 33 days is 38.46%.

The application discloses a collagen membrane and a preparation method and application thereof, and belongs to the cosmetic field. The preparation method of the collagen membrane comprises the following steps: using lime to pickle a cowhide, washing the cowhide, then using hydrochloric acid to acidify the cowhide, washing the cowhide, washing away the interstitial substance, until the hardness of the cowhide is less than 0.1-0.3 mmol / 100g; cutting the obtained cowhide into pieces, crushing the pieces by using a fiber removing machine, obtaining collagen fibers, then adding a gelatinized acetic acid ester starch solution and a chitosan solution into the collagen fibers, uniformly mixing and rubbing the collagen fibers, and obtaining a collagen fiber slurry with a water content of 95-97%; casting the obtained collagen fiber slurry into a film, drying the film at 50-55 DEG C. for 2-4h, then soaking the film in a mixed solution of baking soda and glutamine transaminase for 2-3s, drying the film at 50-55 DEG C., then washing the film by using a sodium thiosulfate solution, and washing away the salt, so that the collagen membrane is obtained. The preparation method enhances the crosslinking between the collagen fibers, and improves the structural stability of the film.

The application discloses silica prepared based on a pH shock strategy and a method thereof, and comprises the following steps: S1: preparing a sodium silicate aqueous solution and an acid hydrolyzed starch solution; S2: controlling gel self-assembly through a pH shock strategy; the acid hydrolyzed starch solution is added into the sodium silicate solution, and is fully stirred and mixed to form a uniform mixed solution; acid liquid is slowly added into the mixed solution, and pH is adjusted to 2-4; then, high-concentration sodium silicate aqueous solution is added to adjust pH to 8-10; acid liquid is added again, and pH is adjusted to 2-4; S3: the gel formed in the step S2 is aged and washed; S4: the washed gel is dried and calcined to obtain high-pore-volume silica. Through accurate control of the ratio of a silicon source and a biomass template, control of pH-induced self-assembly of silicon species on a starch template and effective control of the assembly kinetics of the two in a solution through a pH shock strategy, a new way is provided for low-cost and environment-friendly manufacturing of high-performance porous silica materials.

The invention belongs to the field of oral ulcer film treatment, and particularly discloses a responsive slow-release double-layer film for treating oral ulcer and a preparation method of the responsive slow-release double-layer film. The double-layer film comprises an inner starch layer and an outer pectin layer, the starch layer is loaded with pyrogallol-zinc nano-enzyme (PA-Zn), and the mass concentration of the PA-Zn is 0.2%-0.6% of that of the starch layer. And the outer pectin layer contains glycerol and a calcium chloride solution. During preparation, a PA-Zn-containing starch solution is subjected to tape casting to form a film, the film is covered with a pectin solution after being half-dried, and the film is formed through drying and humidity balance treatment. According to the membrane, the starch layer is specifically degraded through salivary amylase to achieve responsive slow release of PA-Zn (the in-vitro simulated release time is 1-72 hours), the membrane is excellent in mechanical performance (the tensile strength is 0.5-13.1 N / mm, and the adhesion strength is 0.5-1.16 N) and high in biological safety (the organ pathology score is not obviously different from that of a healthy group), and the membrane is suitable for oral ulcer treatment drugs or medical instruments.

The application relates to the technical field of mulch film preparation, and particularly discloses a high-strength recyclable high-heat-retention mulch film and a preparation method thereof. The high-strength recyclable high-heat-retention mulch film comprises the following raw materials in parts by weight: 65-75 parts of polyethylene, 5-10 parts of cationic starch solution, 15-20 parts of a composite phase change material, 0.3-0.7 parts of an antioxidant and 0.5-1.1 parts of a light stabilizer; wherein the composite phase change material is a silver-plated expanded graphite / modified paraffin composite phase change material. The high-strength recyclable high-heat-retention mulch film has the advantages that the mechanical properties and heat-retention performance of the mulch film can be improved, and the defects that the mechanical properties and heat-retention performance of the mulch film are still insufficient are eliminated.

The invention relates to a porous starch microsphere as well as a preparation method and application thereof, and belongs to the technical field of embolism microspheres. The preparation method comprises the following steps: heating and gelatinizing starch in an alkaline aqueous solution, and adjusting the pH value to 7-8 to obtain a starch solution; mixing the starch solution, a cross-linking agent and a polyvinyl alcohol aqueous solution to obtain a water phase; wherein the cross-linking agent comprises sodium trimetaphosphate and / or sodium tripolyphosphate; mixing the water phase and the oil phase, and carrying out a cross-linking reaction to obtain gel microspheres; and placing the gel microspheres in water, and heating until the polyvinyl alcohol is dissolved to obtain the porous starch microspheres. Starch is used as a raw material, polyvinyl alcohol and sodium trimetaphosphate and / or a sodium tripolyphosphate cross-linking agent are not easy to react, and a porous structure with a controllable aperture is formed in situ, so that various types of drugs can be effectively embedded and loaded, and efficient loading and slow release of the drugs are realized in combination with the degradable characteristic of the starch.