186 results about "Chitosan membrane" patented technology

The invention discloses a method for preparing three-dimensionally sequentially porous chitosan bone repair scaffold material. The method comprises the steps of dissolving chitosan powder in dilute acetic acid and standing to defoam; coating the prepared chitosan solution on the surface of a mold evenly, placing in a solidification solution at room temperature to solid and form a membrane, demoulding and obtaining a chitosan membrane moulding plate; pouring the prepared chitosan solution into the chitosan membrane moulding plate, sealing and soaking in the solidification solution to solid and demould to obtain chitosan gel; and washing the chitosan gel to be neutral by distilled water and drying. The method is simple in preparation technology; the three-dimensionally sequentially porous chitosan bone repair scaffold material prepared is good in regularity and high in strength and porosity, and can meet the requirements of tissue engineering scaffold material.

The invention discloses an optical probe film and a special-purposed organic dye for micro determinations of copper ion contents in water sample. The structural formula of the organic dye provided by the present invention is represented by formula I. On the basis of the organic dye, an active group -COCl is introduced. The -COCl group is subject to an amidation reaction with -NH2 on chitosan, and is fixed on a chitosan film through a covalent bond. With the above processes, an optical probe film is produced. The optical probe film has specific response to copper ions. Because copper ions and organic dye molecules are combined through reversible complexations, when the content of the dissociated copper ions in the water sample is changed, the copper ion content still can be reflected instantly. When in use, the film is immersed in a water sample requiring testing, the film is stood in the water sample for 5 minutes, and analysis and determination can be carried out upon the copper-ion-containing water sample through a spectrophotometer. The optical probe film provided by the present invention has advantages of easy production and low cost. According to the present invention, the optical film does not pollute the water system requiring testing, and can be repeatedly used. With the optical film provided by the present invention, an in situ on-line detection can be realized. (Formula I)

The invention discloses a preparation method of a chitosan membrane. The method comprises the following steps of: dissolving chitosan in 1-carboxymethyl-3-methyl chlorine salt ion liquid water solution of 1-5%, and enabling the chitosan to completely dissolve so as to obtain a stock solution of 1-5 wt% for preparing the chitosan membrane; performing squeezing and filtering; performing standing and defoaming; performing rotary membrane coating on a glass plate; performing drying under constant temperature of 40 DEG C and constant humidity of 50%; performing soaking in a sodium hydroxide solution of 1-5% for 1-5h and stripping a membrane; cleaning the membrane in distilled water till the pH is neutral; and drying the cleaned membrane under the constant temperature of 40 DEG C and constant humidity of 50% so as to obtain the chitosan membrane. According to the chitosan membrane, the thickness is 2.5-3.5 mu m, the breaking strength is larger than or equal to 170MPa, the elongation at break is larger than 3.6%, and the initial modulus is larger than 3.3 GPa. The chitosan membrane can be used as anticoagulant materials, bone repairing materials, wound dressing materials, and the like.

The invention discloses a microcapsule embedded with fixed dominant bacteria. The microcapsule consists of an inner core and a membrane which is coated on the outside, wherein the inner core is a calcium alginate gel bead which comprises dominant bacteria with immobilized nanophase materials; the chitosan membrane is coated on the outside of the inner core; and a sodium alginate membrane is coated on the outside of the chitosan membrane. The microcapsule is prepared through steps of screening of the dominant bacteria, immobilization of the dominant bacteria and so on, and can be effectively applied to treatment of wood pulp paper-making waste water. The method for preparing the microcapsule is simple and has low cost; and the microcapsule prepared has greatly improved mass transfer performance and mechanical strength and has good effect on processing the paper-making waste water.

The invention discloses a chitosan-furfural residue nano-fiber composite membrane preparation method mainly comprising the following steps: furfural residue nano-cellulose is prepared, and a 1-10% nano-cellulose suspension liquid and a 1wt% chitosan acetic acid solution are prepared; the nano-cellulose suspension liquid is added into the chitosan acetic acid solution, and magnetic stirring is carried out for 1.5h; when the material is dissolved, ultrasonic dispersion is carried out for 30min; after vacuum degassing, the mixed solution is spread on a polytetrafluoroethylene plate with a flat surface; the solution is dried for 72h under vacuum and under a temperature of 45 DEG C; an obtained membrane is soaked in a 0.5mol/L NaOH solution for further neutralization; deionized water is used for washing; and the membrane is dried, such that the chitosan-furfural residue nano-fiber composite membrane is obtained. The method has the advantages that: no expensive equipment such as high-pressure homogenization equipment is needed, such that production cost is reduced; problems such as low mechanical strength and poor water resistance of chitosan membrane are solved; no complicated modification operation upon chitosan is needed, and the composite material with excellent performance can be obtained by simply adding natural high-molecular fiber.

A high-flux detection system and the electrochemistry immune analytical method to detect many analytes at the same time has provided in the invention. It uses the functional chitosan membrane modified by the medium to fix the antigen molecule combining with the competitive immune analytical method, so the antigen in electrode surface competes with the antigen in sample to combine with the enzyme labeled antibody in warm cultivating solution to link the part antibody into the electrode surface, which catalyses the reaction between the H2O2 and the Toluidine Blue fixed in the electrode surface to get the detected antigen content in solution indirectly by the current catalyzed by the H2O2 oxidation. So the electrical medium is fixed in the electrode surface to avoid the signal cross generated by the diffusion which is the immune sensor array without disturbance. Combining with the flowing injection technology, it reaches the high-flux detection output. The sensor array is simple and cost little, also it has the short analyzing time and high sensitivity, so it is important to the life analytical chemistry, the immune science and the clinical medicine.

The invention discloses a preparation method of a cellulose nanocrystal and chitosan composite membrane, and belongs to the field of modification of natural polymers. The method comprises the steps that cellulose nanocrystal (CNC) sol is prepared by conducting concentrated sulfuric acid hydrolysis on microcrystalline cellulose; the cellulose nanocrystal (CNC) sol is reacted with sodium periodate to prepare dialdehyde cellulose nanocrystal (DAC) sol and the cellulose nanocrystal (CNC) sol is reacted with a Girard's reagent T to prepare cationic cellulose nanocrystal (CDAC) sol. The CDAC sol is directly mixed with a chitosan-acetic acid solution, vacuum defoamation tape casting is conducted in a polytetrafluoroethylene mold, drying at room temperature is conducted, and the membrane is obtained. Compared with a pure chitosan membrane, the mechanical property of the prepared cellulose nanocrystal and chitosan composite membrane can be obviously improved, and the swelling degree in water is obviously reduced.

The invention relates to a method for preparing a biological polysaccharide self-assembly modificatory chitosan antibacterial biological material, which is characterized by comprising the following steps: (1) preparing a lentinan derivant, i.e. lentinan sulfate; (2) preparing a chitosan membrane base material; (3) preparing a lentinan sulfate solution and a chitosan solution; and (4) carrying outlayer-by-layer self-assembly of the lentinan sulfate and the chitosan on the surface of the base material: respectively carrying out alternative self-assembly on the chitosan membrane base material in the lentinan sulfate solution and the chitosan solution for 5 times to obtain a surface layer-by-layer self-assembly modificatory chitosan mebrane containing 5 bilayers with the outermost layer of the lentinan sulfate, washing and drying to obtain the biological polysaccharide self-assembly modificatory chitosan antibacterial biological material. The chitosan antibacterial biological material prepared by the method has excellent antibacterial activity; and the method has simple preparation process, easy control, mild preparation conditions and low cost.

The invention relates to a preparation method of a biological composite, in particular to a preparation method of chitosan reinforced rod, providing a preparation method of chitosan reinforced rod which has favorable mechanical property and is biodegradable, absorbable and can be taken as bone fracture internal fixation. The preparation method is characterized in that: chitosan powder is added into the acetic acid solution in which poly-lactic acid short fiber is dispersed, the solution is agitated to form a chitosan/acetic acid solution; the chitosan/acetic acid solution is smeared on the inner wall of a mould, the mould is immersed and precipitated into sodium hydroxide solution, and then chitosan membrane taken as a mould board for in situ precipitation is obtained; the mould is filled with the chitosan/acetic acid solution, and then the mould are taken off in the sodium hydroxide solution, while the chitosan/acetic acid solution is immersed into the sodium hydroxide solution until the whole chitosan gel rod is formed; the chitosan gel rod is immersed into distilled water till the water is neutral, and then the rod is dried, at last the poly-lactic acid short fiber reinforced transparent yellowish chitosan rod is obtained.

The invention discloses a preparation method of a silver-loaded nano cellulose-chitosan composite film, the preparation method of the silver-loaded nano cellulose-chitosan composite film comprises the following steps: adding sodium periodate into a nano cellulose solution, stirring in a dark place, centrifuging for separation, and washing to obtain dialdehydo nano cellulose; adding a newly-prepared saturated silver ammonia solution for preparation of silver-loaded nano cellulose; mixing the silver-loaded nano cellulose with a chitosan solution to obtain a silver-loaded nano cellulose-chitosan antibacterial film. Nano silver particles prepared in the method are evenly distributed in dialdehydo nano cellulose network structures, the easy agglomeration problem of the nano silver particles can be well solved, the preparation process does not require the use of special instruments, also does not need a chemical reducing agent, and the production cost is reduced. Through use of good mechanical properties of the nano cellulose, the low mechanical strength problem of the chitosan film is improved, and the antibacterial property of the chitosan film is improved by silver loading operation. The silver-loaded nano cellulose-chitosan composite film has broad application prospects in antibacterial wound dressings and food packaging and other industries.

The invention relates to the technical field of medical application, and in particular relates to wound regenerating and repairing bandage and a manufacture method thereof. The wound regenerating and repairing bandage comprises a surface protective layer, wherein a therapy pad is arranged at one side of the surface protective layer, and comprises a nano-fiber membrane, an anti-bacterial chitosan membrane and an alginate layer which are arranged in sequence; the alginate layer is connected with the surface protective layer. The wound regenerating and repairing bandage manufactured by using the method has a remarkable effect in stopping bleeding, resisting bacteria, accelerating wound heating and relieving pains for a wound, is excellent in adhesion, breathability and comfort, can prevent wound adhesion, and has high functions of water absorption and moistening.

The invention discloses a manufacturing method of a chitosan-PE (poly ethylene) double-layer bacteriostatic preservative film, and belongs to the technical field of agricultural product preservation. The method comprises the steps that acid-soluble chitosan is dissolved in acetum fully; Span40, glycerol and origanum oil are added respectively, stirred uniformly, homogenized and subjected to the vacuum degassing to obtain a chitosan film liquid, and the chitosan filmliquid is uniformly cast on a film formation medium laid with a PE preservative film; the coating quantity is 3-4mL/cm<2>; the film formation medium coated with the chitosan film liquid is placed in an oven for drying; when the moisture content of a chitosan film reaches 8-10%, the film is uncovered to obtain the chitosan-PE double-layer bacteriostatic preservative. With the adoption of the chitosan-PE double-layer bacteriostatic preservative film, the microorganic pollution and the moisture loss of meat during processing, transportation and storage courses can be reduced; a novel effective preservative approach is provided for meat products; the quality of the meat products is improved; and the economic benefit of the meat products is increased.

The invention discloses a chitosan-calcium alginate gel microsphere soft tissue reinforced material, its preparation method comprises preparing calcium alginate gel microsphere from sodium alginate solution, forming film from calcium alginate gel microballoon and chitosan, and mixing the chitosan-calcium alginate gel microsphere with sodium alginate solution.

The invention discloses a preparation method of a metal ion selective separation composite membrane. The preparation method is characterized in that the composite membrane utilizes polyvinylidene fluoride as a framework material of natural biological material chitosan, so that the mechanical property and a reusing property of a chitosan membrane are strengthened; a molecular imprinting technology is imported, so that a metal ion has a selective separation function. The preparation method takes soluble salt of chitosan, polyvinylidene fluoride and metal M as a raw material to prepare an M ion imprinting chitosan/polyvinylidene fluoride composite membrane by process of sol-gel and templated processing, the preparation technology is simple, the cost is low, the condition is gentle, and the preparation method is pollution-free. The composite membrane provided by the invention has the advantages that metal M ions in a water body are removed selectively with high efficiency and low cost, and the composite membrane belongs to the technical field of water body heavy metal membrane separation and has remarkable environmental benefits and economic benefits.

A chitosan membrane containing nanosize particles is disclosed in this invention. The chitosan membrane comprises a chitosan membrane and nano-inorganic particles. The nano-inorganic particles are uniformly embedded in the chitosan membrane. This invention also discloses a method for forming a chitosan membrane containing nanosize particles. The method comprises a grinding process, a dissolution process, a dispersion process, a blending process, an impurity removing process, a degassing process, a casting process, and a fixation process.

The invention discloses a preparation method and application of a palladium adsorption material. The preparation method comprises the following steps: blending chitosan and montmorillonite, adding glutaraldehyde to serve as a cross-linking agent, and preparing a chitosan-montmorillonite cross-linking blended film. The defects that the chitosan is poor in mechanical performance and low in acid resistance can be overcome, the cross-linking blended film serves as a palladium adsorption material, and precious metal palladium can be effectively adsorbed and separated. The palladium adsorption material prepared by the method provided by the invention is in a film structure, serves as solid-phase packing to prepare an adsorption column and has the advantages of improving mass transfer resistance and promoting elution.