34 results about "Chitosan membrane" patented technology

The invention discloses a green preparation method for realizing a high-performance chitosan film through pH regulation and control of a citric acid buffering agent, and belongs to the field of food packaging and high polymer materials. According to the method, a water phase separation method is adopted, a citric acid buffering agent serves as a water phase environment, and a chitosan solution is induced to be subjected to phase separation and gelation by regulating and controlling the pH value (preferably 5.0-5.5) of the citric acid buffering agent. The preparation method comprises the following specific steps: dissolving chitosan powder in an alkali urea solvent (KOH: urea: water = 7: 12: 81), inducing gelation through a citric acid buffer agent, carrying out solvent replacement through an ethanol solution, and drying and curing. According to the method, a chemical cross-linking agent does not need to be used, and the core is that a buffer system is used for regulating and controlling the phase separation process to promote aggregation among chitosan molecular chains, so that a compact physical structure network is constructed. The prepared chitosan film has excellent mechanical strength, water resistance, gas barrier property, biocompatibility and degradability, and is suitable for the fields of food, medicine packaging and the like.

The invention discloses a method for extracting and preparing angelica keiskei exosomes. The method comprises the following steps: S1, selecting an angelica keiskei sample and selecting chitosan; s2, crushing and filtering the angelica keiskei sample to obtain an extracting solution; s3, dissolving chitosan through acetic acid, forming a film through a rotary coater, and carrying out drying and heat treatment; s4, mixing the extracting solution with the dried chitosan membrane, and adsorbing the exosome through the charge effect; s5, putting the chitosan membrane into a tangential flow filtration system, collecting effluent after tangential flow filtration, and purifying the effluent; and S6, pre-freezing the purified solution, and carrying out drying treatment. The invention also discloses application of the method. The method has the beneficial effects that the angelica keiskei sample is crushed and filtered to obtain the extracting solution, then the extracting solution and the dried chitosan film are mixed at room temperature, the exosome is adsorbed through the charge effect, and the exosome is purified after being filtered by the tangential flow filtering system, so that a large amount of high-purity exosome is obtained, and the method is simple, convenient and efficient.

The present invention provides a medical implant, comprising (a) a matrix layer comprising chitosan; and (b) a reinforcement structure comprising polymer filaments or polymer fibers, whereby the reinforcement structure is incorporated into the matrix layer. The invention further relates to the medical implant for use in the treatment of ophthalmological diseases or skin disorders. The invention finally relates to a method for producing the medical implant of the invention.

The application discloses a solid-phase preparation method of sulfonated chitosan membrane and application of the sulfonated chitosan membrane in catalytic biodiesel preparation, and the sulfonated chitosan membrane is prepared by the following steps: chitosan powder is suspended in a dispersant in which a sulfonating agent is dissolved to perform a sulfonating reaction, sulfonated chitosan powder is obtained through solid-liquid separation, the sulfonated chitosan powder is dissolved in a membrane solvent to prepare a casting membrane liquid, the casting membrane liquid is naturally cast on a glass surface to form a membrane, and the sulfonated chitosan membrane is obtained after drying and removing the membrane solvent. The sulfonated chitosan membrane is added into a mixed solution of fatty acid and methanol, and after stirring and heating for a period of time, the sulfonated chitosan membrane is taken out, and biodiesel is obtained after removing methanol from the solution. The sulfonated chitosan membrane prepared by the application has the advantages of fast mass transfer rate, high catalytic efficiency and easy separation, and under the conditions of an alcohol / oil ratio of 10:1, a reaction temperature of 65 DEG C, a catalyst dosage of 5wt%, and a reaction time of 3h, the esterification rate reaches 92.29%. Under the same conditions, the esterification rates of powdered chitosan and commercially available macroporous ion exchange resin are 57.73% and 33.0% respectively.

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 invention belongs to the technical field of food packaging materials and bacteriostatic packaging films, and discloses an active packaging film capable of generating singlet oxygen bacteriostasis based on light driving, a preparation method and application of the active packaging film in fresh keeping of fruits, vegetables and edible mushrooms, and the active packaging film comprises the following steps: S1, obtaining a chitosan film solution A for later use; s2, obtaining a polyvinyl alcohol membrane solution B for later use; s3, obtaining a polyvinyl alcohol / chitosan composite membrane solution D based on food-grade nano silicon dioxide loaded sodium copper chlorophyllin; s4, preparing the bacteriostatic active packaging film, and using the bacteriostatic active packaging film in combination with blue-violet light. The antibacterial film disclosed by the invention has the advantages of high barrier property, ultraviolet-resistant optical property, strong and flexible mechanical property, good thermal stability, biodegradability and antibacterial property of CD-ROM movable product singlet oxygen (1O2). The packaging film can be used as a bio-based active package, can reduce the environmental pollution of a traditional petroleum-based packaging film, can prolong the shelf life of fruits, vegetables and edible mushrooms, and has the dual effects of environmental protection, bacteriostasis and preservation.

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.

The preparation method comprises the following steps: S1, adding a certain amount of tin-doped indium oxide and carbon nanotubes into an aqueous solution containing aniline and hydrochloric acid, carrying out ultrasonic dispersion for 1-2 hours, then adding ammonium persulfate, and carrying out a reaction for a certain time, so as to obtain a solution A; centrifuging, washing and drying to obtain polyaniline modified carbon nanotubes and tin-doped indium oxide particles; s2, mixing polyaniline modified tin-doped indium oxide, carbon nanotubes, chitosan, acetic acid, citric acid and distilled water, mechanically stirring and uniformly dispersing, then performing ultrasonic treatment to remove bubbles, pouring a film forming solution into a polytetrafluoroethylene mold for tape casting, and then putting the film forming solution into a drying oven for treatment to obtain the antibacterial flame-retardant infrared stealth functional chitosan film. According to the invention, by means of the synergistic effect among the carbon nanotubes, the tin-doped indium oxide, the polyaniline and the chitosan, the chitosan film has extremely low infrared emissivity, and a good infrared stealth effect is achieved.

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 lignin nanoparticle-perilla essential oil Pickering emulsion / chitosan composite membrane as well as a preparation method and application thereof. The composite membrane comprises a chitosan matrix and lignin nanoparticle-perilla essential oil Pickering emulsion uniformly dispersed in the chitosan matrix, the emulsion is prepared by mixing perilla essential oil with the volume fraction of 30% and lignin nanoparticle suspension with the mass concentration of 0.25%-1.00% according to the volume fraction of 10%-50%, and the Pickering emulsion and a chitosan solution are compounded according to the mass ratio of 2%-8% and then cast into a film. The composite film effectively solves the problems that the perilla essential oil is easy to volatilize and oxidize and the chitosan film is poor in mechanical property and barrier property, has excellent tensile strength, elongation at break, hydrophobicity, antioxidant activity and antibacterial property, and can realize slow release of the perilla essential oil; the packaging material can be widely applied to the field of fresh-keeping and antibacterial packaging materials for perishable fruits (such as strawberries).

The application discloses a preparation method of a glucose oxidase sensor with a porous structure outer membrane, and steps of the method comprise the following steps: a chitosan outer membrane is prepared on the surface of a glucose oxidase sensor assembly; solid particles of salt are added into a pre-solidified PDMS solution, ultrasonic mixing is performed to obtain a salt-PDMS mixed solution, the salt-PDMS mixed solution is dropped into a groove, and air in the groove is extracted by vacuum; then the glucose oxidase sensor assembly with the chitosan outer membrane is immersed into the salt-PDMS mixed solution in the groove, and the glucose oxidase sensor assembly is taken out and solidified repeatedly for multiple times until a PDMS outer membrane with a set thickness is formed on the chitosan membrane layer; and then the salt particles in the PDMS outer membrane are dissolved by deionized water to obtain the glucose oxidase sensor with the porous structure outer membrane. The sensor prepared by the method has chitosan and PDMS with the porous structure as outer membrane materials, the preparation method is simple, and product quality control is convenient.

This invention relates to a method for preparing an expanded perlite-fly ash composite thermal insulation material, belonging to the field of thermal insulation material technology. The method includes the following steps: coating the surface of expanded perlite with polystyrene and acrylic acid via emulsion polymerization to obtain modified expanded perlite; coating the surface of the modified expanded perlite with a chitosan film to obtain a composite material; modifying fly ash with a silane coupling agent to obtain modified fly ash; and crosslinking the modified fly ash and the composite material with glutaraldehyde to obtain the expanded perlite-fly ash composite thermal insulation material. In this invention, coating the surface of expanded perlite with polystyrene and acrylic acid increases its water resistance and strength, improving its thermal insulation properties. Then, coating with a chitosan film and crosslinking with the modified fly ash increases the bonding force between the expanded perlite and the fly ash, and also improves the adsorption capacity for heavy metal ions leached from the fly ash, thus improving the overall performance of the composite thermal insulation material.

The application discloses a preparation method of a high-toughness chitosan-based intelligent film with preservation and visual monitoring of fish freshness, which comprises the following steps: firstly, co-coating curcumin and quercetin into zein and chondroitin sulfate to obtain nanoparticles with a core-shell structure; secondly, adding the nanoparticles into a chitosan acetic acid solution; thirdly, adding a plasticizer glycerol, stirring, ultrasonic degassing, and then obtaining a film-forming solution; and finally, drying the film-forming solution at a certain temperature to form the intelligent film. The application creatively co-embeds natural indicators curcumin and quercetin with excellent antioxidant properties to obtain nanoparticles with a core-shell structure, the incorporation of the nanoparticles effectively improves the physical properties and biological activity of the chitosan film, the visual intelligent indicator film is sensitive to the response of the change of the pH value in the environment, can accurately feed back the freshness information of fish and meat food, and is expected to be applied to real-time monitoring of food freshness.

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 application provides a preparation method of a new MOFs particle doped chitosan nanofiltration membrane, which concentrates the crystallization of MOFs particles in a subsequent membrane preparation process, and uses the MOFs particles doped on a support as nucleation centers to attract the "nutrients" in a casting solution to the surface of the support to grow into MOFs particles, so that the content of MOFs particles on the surface of the membrane is reduced, the probability of MOFs loss is reduced, and the movement process of the "nutrients" is also beneficial to the formation of loose pore structures, and is beneficial to the application of the chitosan membrane in nanofiltration.

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.

This invention relates to the field of food additives and food safety control, specifically disclosing a chitosan membrane loaded with galangal essential oil, its preparation method, and its application. The method includes: (1) first contacting an ethanol-water solution of moringa alcohol-soluble protein with a pectin-water solution to obtain a protein-pectin dispersion; (2) second contacting galangal essential oil with the protein-pectin dispersion to obtain a galangal essential oil emulsion; (3) dissolving chitosan, corn starch, and citric acid in water I, followed by gelatinization, and then adding glycerol for a third contact to obtain a membrane solution; (4) fourth contacting the galangal essential oil emulsion with the membrane solution, casting it into a film, and then drying and equilibrating it to obtain a chitosan membrane loaded with galangal essential oil. The method provided by this invention can improve the loading and protective capacity of essential oils, significantly enhance the inhibitory effect on bound heterocyclic amines, and improve the edible safety of heat-processed plant-based meat products.

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 invention discloses a triboelectric nano generator and preparation and application thereof, and belongs to the technical field of functional materials. According to the preparation method, the pure chitosan membrane is prepared by regulating and controlling the concentration and spinning parameters of the chitosan; then mixing the chitosan solution and the bacterial cellulose solution, and obtaining a bacterial cellulose-chitosan composite membrane through an electrostatic spinning technology; then, the bacterial cellulose-chitosan composite film is used as a friction positive electricity layer, a PVDF-TrFE / BaTiO3 / CBC-PANI film is used as a friction negative electricity layer, and a triboelectric nano generator (TENGs) is formed; and finally, applying the triboelectric nano-generator (TENGs) to the field of wound healing. The porous flexible triboelectric nano-generator has good flexibility and high output performance, the voltage is still kept good after the porous flexible triboelectric nano-generator works for 1000 cycles in a high-humidity (99%) environment, the open-circuit voltage is basically kept unchanged, and the porous flexible triboelectric nano-generator has good cycle stability.

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 invention discloses a chitin fiber homogenizer for medical chitosan film preparation, and relates to the field of chitosan film preparation, the chitin fiber homogenizer comprises a homogenizer main body and a buffer box, the two sides of the buffer box are fixedly connected with fixing blocks, the inner bottom end of the buffer box is provided with a damping rod, the damping rod is externally sleeved with a first spring, and the first spring is fixedly connected with the buffer box. The upper end of the damping rod is fixedly connected with a pressing plate, the upper end of the pressing plate is fixedly connected with a sliding rod, and the other end of the pressing plate is fixedly connected with a movable frame. The device has the advantages that the homogenizer main body can be buffered for multiple times through the slide rod, the pressing plate, the damping rod, the first spring, the moving frame, the guide rod, the second spring and other components, so that displacement caused by vibration is effectively avoided, and normal operation of the homogenizer main body can be guaranteed; the homogenizer main body and the buffer tank can be quickly separated through the connecting block, the fixing rod, the fixing sleeve, the rotating rod, the limiting block and other components, so that split maintenance can be realized, and meanwhile, the maintenance difficulty can be reduced.

The present disclosure shows that by combining pH-responsive bridging chitosan polymer chains and a tough hydrogel dissipative matrix one can achieve unprecedented ultra-tough adhesion to tissues (>2000J / m2) in 5-10 mins without covalent bond formation. The strong non-covalent adhesion was shown to be stable under physiologically relevant conditions and strongly influenced by chitosan molecular weight. molecular weight of polymers in the matrix, and pH. The adhesion mechanism relies primarily on the topological entanglement between the chitosan chains and the permeable adherends. The present disclosure also discloses dry polymer films to generate instant adhesion between hydrogel-hydrogel and hydrogel-elastomer surfaces. Unprecedented adhesive energies (>3000J / m2) between alginate-polyacrylamide tough hydrogels were achieved instantaneously using an intermediate chitosan film, governed by pH change, H-bonding, and bridging polymer entanglement. Furthermore, this strategy also generates instant strong adhesion between acrylic elastomers and tough hydrogels with adhesion energy as high as 4000J / m2.