17 results about "Chitosan membrane" patented technology

This invention discloses a method for preparing and applying a chitosan-nanofibrillar-based smart indicator membrane loaded with anthocyanins and alizarin. The method includes the following steps: mixing beet powder with hydrochloric acid, washing with water until neutral, and drying; adding sodium hydroxide solution, mixing and reacting, washing with water until neutral, and drying; adding sodium chlorite solution, mixing, adjusting the pH to 3-3.5, reacting, and washing with water until neutral to obtain beet fiber; adding water, homogenizing under ultra-high pressure to obtain a beet nano-suspension; adding the beet nano-suspension to a chitosan-acetic acid solution and stirring, then adding glycerol; adding pigments, mixing, and obtaining a membrane solution; ultrasonically degassing, and drying to form a membrane. This membrane, as a food preservation indicator membrane, possesses both the characteristics and functions of food preservation and indicating food freshness; using beet nanofibers as a supplementary material improves the mechanical properties of the chitosan membrane; the addition of alizarin and anthocyanin mixed pigments enriches the color changes of the indicator membrane and improves its stability.

The application belongs to the technical field of bio-based packaging materials, and particularly relates to a novel double-layer composite film and application thereof. The novel double-layer composite film comprises the following steps: reacting palmitic anhydride and carboxymethyl cellulose to obtain carboxymethyl cellulose palmitate; adding a pH-sensitive natural dye indicator to obtain carboxymethyl cellulose palmitate nanoemulsion containing a pH-sensitive substance; then loading a natural polymer material to prepare a film material; finally adding the film material to the carboxymethyl cellulose palmitate to prepare a composite film, thereby obtaining the novel double-layer composite film. The double-layer composite film can be self-emulsified without adding a surfactant, and has the ability to load functional indicator (pH-sensitive color indicator) substances; meanwhile, the barrier performance of the film material, such as a chitosan film, to water vapor and oxygen is improved, and the double-layer composite film has a very promising application in food or fruit preservation. The method provided by the application is not only green in raw materials, but also uses a flow casting method, which can be applied to industrial production and has a good application prospect.

The utility model relates to the technical field of band-aids, and discloses a band-aid containing dehydrated gel and a chitosan protective film, which comprises a non-woven fabric body, two viscose layers and a dehydrated gel layer are arranged at the top end of the non-woven fabric body, the two viscose layers are respectively positioned on two sides of the dehydrated gel layer, and the dehydrated gel layer is positioned on the bottom end of the non-woven fabric body. A chitosan film covers the top end of the dehydrated gel layer, an anti-sticking layer is stuck to the top end of the adhesive layer, and connecting paper is fixedly connected to the corner position of the side, close to the chitosan film, of the anti-sticking layer. According to the technical scheme, through the arrangement of the connecting paper, a user can directly tear down the anti-sticking layer from the adhesive layer under the condition that the user does not make contact with the chitosan film, the user can tear down the anti-sticking layer by means of force, meanwhile, the anti-skid protruding blocks can improve the anti-skid performance of the connecting paper, the use experience of the user is improved, and the use experience of the user is improved. The practicability is high.

The invention discloses functional nano zinc oxide as well as a preparation method and application thereof, and belongs to the technical field of food packaging materials and functional nano composite materials. The preparation method comprises the following steps: dissolving dialdehyde cellulose in a hydrochloric acid solution, mixing with a procyanidine solution dissolved in DMSO (Dimethylsulfoxide), heating to react, dialyzing and drying to obtain a cellulose-polyphenol graft; and uniformly mixing the cellulose-polyphenol graft aqueous solution with a zinc nitrate aqueous solution, adjusting the pH value, carrying out a hydrothermal reaction, carrying out centrifugal separation, washing the precipitate, and drying to obtain the functional zinc oxide nanoparticles. Through an aldehyde cellulose-polyphenol grafting strategy, the particle size controllability and dispersity of ZnO nano particles are improved, the ZnO nano particles are endowed with higher specific surface area and functionality, and after the ZnO nano particles are loaded to a chitosan film, the oxidation resistance, antibacterial property and mechanical strength of the film are remarkably enhanced.

This invention discloses a topologically oriented cyclodextrin / chitosan composite membrane, its preparation method, and its applications, belonging to the field of bio-based nanomaterials technology. Using α-cyclodextrin and polyethylene glycol (PEG) as raw materials, this invention prepares topologically oriented cyclodextrin-PEG "ring-slippery" nanoparticles (TNPs). TNPs, as green and biodegradable nanoparticles, fill the chitosan network matrix, enhancing hydrogen bonding interactions with chitosan molecules and improving the mechanical properties of the chitosan membrane. This method not only uses simple raw materials and is easy to implement, but also effectively improves the mechanical strength of the chitosan composite membrane, effectively overcoming the problem of poor mechanical strength in existing chitosan composite membranes, and providing a simple and effective approach for practical production.

The invention discloses a chitosan / diatomite coated biochar-based slow release fertilizer and a preparation method and application thereof, and the preparation method comprises the following steps: firstly, mixing biochar, urea and corn starch according to a specific ratio, granulating to prepare a fertilizer core, and then carrying out coating treatment on the fertilizer core by taking a chitosan solution / diatomite as a coating liquid. By adding the diatomite, the mechanical property and swelling property of the chitosan film are improved, and the chitosan film, the diatomite and the biochar have a synergistic effect to delay nutrient release. The fertilizer is simple in preparation process, low in cost and environment-friendly, can remarkably improve the nutrient utilization rate and the crop yield, has the effect of improving saline-alkali soil, and is suitable for green development of agriculture.

This invention provides a method for preparing a chitosan membrane, the chitosan membrane prepared by this method, and its applications. The method includes the following steps: S1: mixing chitosan, acid, C1-C6 monohydric alcohol, pore-forming agent, metal salt, and water to obtain a casting solution; S2: placing the casting solution on a carrier to obtain a carrier loaded with the chitosan membrane; S3: immersing the carrier loaded with the chitosan membrane sequentially in an alkaline solution and water to separate the chitosan membrane from the carrier. The chitosan membrane of this invention has a strong resistance to strong alkalis. When used as an anion exchange membrane material in fuel cells, it has advantages such as high specific power, rapid start-up, non-corrosiveness, low reaction temperature, and low oxidant requirement.

The invention relates to the technical field of biological catalysis, in particular to a preparation method and application of a co-immobilized enzyme based on macroporous resin adsorption-chitosan membrane coating, and the preparation method mainly comprises the following steps: pretreating resin, adding glucose oxidase and catalase, fully adsorbing, and coating with a chitosan membrane to obtain the co-immobilized enzyme, the method can be used for producing gluconic acid. The co-immobilized enzyme prepared by the invention has the characteristics of adaptation to low-pH production, high enzyme activity retention rate and the like.

This invention relates to the field of fruit preservation technology and discloses a method for preserving mangoes containing chitosan, a eutectic solvent, and EGC. The method includes the following steps: adding chitosan to an acetic acid solution and heating and stirring in a water bath to obtain a chitosan film solution; pre-dispersing and wetting epigallocatechin in a eutectic solvent, then adding it to the aforementioned chitosan film solution and stirring at room temperature to obtain a modified chitosan composite film solution; selecting undamaged mangoes, washing and air-drying their surface moisture, immersing them in the modified chitosan composite film solution to evenly coat the surface with the film solution, removing them and air-drying them naturally, repeating the aforementioned immersion and air-drying process, and finally storing the dried mangoes in an indoor environment for preservation. This invention utilizes a eutectic solvent to solve the problem of easy aggregation of polyphenolic active substances, forming a uniform and continuous semi-permeable membrane on the mango peel, limiting moisture loss, achieving slow release of antioxidant components, and significantly extending the mango's shelf life.

The application discloses a preservative film liquid, a preservative film and a preparation method and application thereof in berry preservation, and relates to the technical field of food preservation. The preservative film liquid comprises a self-assembled nanoparticle with a melatonin core and a PEG-40 hydrogenated castor oil shell and a chitosan dispersion liquid, wherein the mass ratio of the PEG-40 hydrogenated castor oil to the melatonin is 0.25:1.2-1.6. The application also provides a preparation method of the preservative film liquid, a preservative film prepared by the preservative film liquid and application thereof in berry preservation. The application loads the melatonin in the chitosan film and overcomes the negative influence of the melatonin on the performance of the chitosan film material, so that the preservative film has good mechanical performance, barrier performance and continuous preservation function, and has important significance for the preservation of perishable foods such as berries.

The invention discloses a food oxygen-uptake packaging double-layer film and a preparation method thereof. The preparation method comprises the following steps: S1, dissolving polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol solution, adding glycerol, stirring, acidifying, adding citric acid, and stirring and reacting at 50-98 DEG C for 5-10 hours; adding gallic acid, stirring and reacting at 50-98 DEG C for 1-2 hours, and obtaining a membrane casting solution A after the reaction is finished; casting the membrane casting solution A into a mold, and drying to form a modified polyvinyl alcohol membrane layer; s2, dissolving chitosan in an acetic acid aqueous solution with the mass concentration of 1-2% to obtain a chitosan solution, adding glycerol, stirring, then adding sodium carbonate, and stirring at 55-70 DEG C for 0.5-2 hours to obtain a membrane casting solution B; casting the membrane casting solution B on the modified polyvinyl alcohol membrane layer in the mold, and drying to form a modified chitosan membrane layer; and demolding to prepare the food oxygen uptake packaging double-layer film. The food oxygen-absorbing packaging double-layer film prepared by the method disclosed by the invention has the advantages of efficient oxygen-absorbing performance, excellent mechanical property and degradability.

The invention discloses a quaternization synergistic metal coordination chitosan-based anion exchange membrane and a preparation method thereof. The quaternization and metal coordination chitosan membrane is obtained by dissolving and uniformly mixing chitosan, quaternization chitosan and water-soluble transition metal salt, pouring and drying to form the membrane. According to the method, rich hydroxyl groups and amino groups in chitosan are coordinated with metal ions, so that not only is a firm network structure formed, but also OH <-> exchange capacity is provided by formed transition metal coordination cations. Meanwhile, due to the introduction of the quaternized chitosan, cation active sites are increased, and an ion transmission channel is expanded through steric hindrance and an electrostatic repulsion effect. According to the synergistic strategy, the ionic conductivity and the mechanical strength of the chitosan membrane are synchronously improved, and a new strategy is provided for developing a high-performance anion exchange membrane.

The present application provides a modified oxygen-releasing nano-peroxide for degrading organic pollutants, a preparation method therefor and a use thereof, and a composite slow-release oxygen material, a preparation method therefor and a use thereof. The modified oxygen-releasing nano-peroxide comprises an oxygen-releasing nano-peroxide, a pH regulator, a polyvinyl alcohol-poly(N-isopropylacrylamide) membrane layer, and a cross-linked chitosan membrane layer. The polyvinyl alcohol-poly(N-isopropylacrylamide) membrane layer encapsulates the oxygen-releasing nano-peroxide and the pH regulator, and the cross-linked chitosan membrane layer encapsulates the polyvinyl alcohol-poly(N-isopropylacrylamide) membrane layer. The modified oxygen-releasing nano-peroxide has high purity and good dispersibility, can maintain stable dissolved oxygen content in water for a relatively long time, and has minimal impact on the environmental pH.

The invention discloses a full-bio-based antibacterial composite film for fresh keeping of fruits and vegetables as well as a preparation method and application of the full-bio-based antibacterial composite film, and belongs to the technical field of bio-based food packaging materials. The problems that a pure chitosan film is poor in mechanical property, insufficient in barrier property and single in function are solved. The composite membrane is prepared by taking chitosan as a matrix, introducing a natural cross-linking agent genipin, a reinforcing phase sulfonated nano cellulose whisker and a functional component lemon grass essential oil, and carrying out the steps of curtain coating, drying and the like. Through the synergistic effect of genipin crosslinking and nanocellulose enhancement, the mechanical strength and barrier property of the composite film are remarkably improved, and the composite film is endowed with broad-spectrum antibacterial, antioxidant and excellent anti-ultraviolet functions. All components of the membrane are derived from natural renewable resources, and the membrane is safe and biodegradable. Application experiments show that when the preservative is applied to preservation of perishable fruits and vegetables of cherries and tomatoes, the growth of microorganisms can be effectively inhibited, the quality deterioration is delayed, the weight loss rate is reduced, the hardness is maintained, the shelf life is remarkably prolonged, and the preservative has important application prospects.

The application discloses a kind of based on MXene load ε-polylysine degradable photothermal antibacterial composite film and its preparation and application.The MX@PL composite nanomaterial is prepared by the electrostatic self-assembly of the successfully etched MXene and ε-PL, then glycerol plasticizer-containing chitosan film liquid is added and stirred uniformly, and the degradable packaging film with photothermal antibacterial property is prepared by solvent casting method after ultrasonic degassing.Both the shortcomings of the cationic ε-PL being easily interacted with the anion components of food matrix to hinder the antibacterial activity and the two-dimensional nanoparticles with photothermal antibacterial property are obtained.

The application relates to the field of water treatment, and particularly discloses a semi-permeable membrane for seawater desalination and a preparation method thereof; the semi-permeable membrane for seawater desalination is composed of an aromatic polyamide membrane and an adsorption layer; the adsorption layer is composed of a chitosan membrane and rebound particles; the chitosan membrane comprises: a chitosan solution, graphene modified flexible fibers, glycerol and glutaraldehyde; the preparation method is as follows: the chitosan solution, the graphene modified flexible fibers, the glycerol and the glutaraldehyde are uniformly mixed and stirred, and are cast into a film; the rebound particles are uniformly sprayed on the surface of the film layer to obtain the adsorption layer; the aromatic polyamide membrane is uniformly sprayed with an ethyl cellulose solution around the periphery; then, the side of the adsorption layer provided with the rebound particles is adhered to one side of the aromatic polyamide membrane which is sprayed with the ethyl cellulose solution; and the semi-permeable membrane is prepared through drying; under the condition of long-time use, the semi-permeable membrane still has high separation efficiency, and the surface of the semi-permeable membrane is not easy to attach bacteria, viruses, aquatic organisms and other substances, so that the semi-permeable membrane has a long service life.

This invention provides a method for cultivating jackfruit resistant to rust spot disease, comprising the following steps: Step 1, water and fertilizer management; Step 2, canopy shaping and pruning; Step 3, topdressing management; Step 4, rust spot disease prevention and control; Step 5, fruit management; and Step 6, harvesting and post-harvest management. In Step 1, the invention applies a specially formulated composite substrate to improve the soil ecology from the root level, inhibit soil-borne pathogens, induce plant resistance, and enhance tree health. During the critical period of disease infection, in Step 4, a protective agent composed of chitosan, horsetail fermentation liquid, and compound microbial fermentation liquid is sprayed. This agent integrates physical barriers (chitosan membrane), physiological enhancement (horsetail active silicon), and biological antagonism (beneficial microorganisms) to form a dynamic protective layer. Through multi-dimensional intervention combining symptomatic and root-cause treatment with prevention as the primary focus, the invention effectively prevents and controls the occurrence and damage of rust spot disease, achieving a long-lasting and stable control effect.