72 results about "Dialdehyde cellulose" patented technology

The invention discloses a dendritic cellulose-based amphoteric flocculating-decolorizing agent and a preparation method of the dendritic cellulose-based amphoteric flocculating-decolorizing agent. The dendritic cellulose-based amphoteric flocculating-decolorizing agent is characterized in that a cellulosic material is mainly taken as a molecular framework; the cellulosic material is oxidized into dialdehyde cellulose by utilization of sodium periodate; then an aldehyde group and an amino group are used to form a Schiff-base structure; the flocculating-decolorizing agent is formed by means of bonding and grafting polyethyleneimine; the cellulosic material, the sodium periodate and the polyethyleneimine are sequentially added for preparation by means of taking water as a solvent; the surface charge characteristic and active site of the flocculating-decolorizing agent are regulated by means of changing a mass ratio of the cellulosic material to the polyethyleneimine. The dendritic cellulose-based amphoteric flocculating-decolorizing agent has the advantages of high flocculation efficiency, stable effect, environmental friendliness, and efficient application in purification treatment of complex water body, such as papermaking, printing and dyeing, heavy metal containment and the like.

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 provides a preparation method of oxidized dialdehyde cellulose immobilized urease. The preparation method comprises the steps of preparation of oxidized dialdehyde cellulose and preparation of immobilized urease, wherein the step of preparation of oxidized dialdehyde cellulose comprises the substeps of activation of cellulose and preparation of the oxidized dialdehyde cellulose through hydrothermal synthesis; and the step of preparation of immobilized urease comprises the substeps of preparation of a dispersed phase, immobilization of urease and washing and drying. The preparation method is characterized by utilizing the cellulose widely existing in the nature as a matrix material to prepare an oxidized dialdehyde cellulose carrier through hydrothermal synthesis and utilizing Schiff base reaction to immobilize urease on the carrier, thus obtaining the oxidized cellulose immobilized urease. The preparation method has the following beneficial effects: the prepared oxidizeddialdehyde cellulose has higher content of aldehyde groups, thus providing more active sites for urease bonding; the method of immobilizing urease is simple and is easy to operate; and the carrier has wide material sources. Thus, the preparation method has wide application prospects and practical values.

The invention discloses a polyethyleneimine based chloramines type antibacterial cellulose membrane, a preparation method and application. The preparation method comprises the following steps: step 1,preparing a cellulose solution with the mass concentration being 5wt percent; step 2, performing casting on a base plate to form a regenerated cellulose membrane after the cellulose solution is defoamed, and washing after solidification, so as to obtain a regenerated cellulose gel membrane; step 3, oxidizing the regenerated cellulose gel membrane through a sodium periodate aqueous solution, so asto obtain dialdehyde cellulose gel membrane with the aldehyde group amount being 1 to 3mmol/g; step 4, dipping the dialdehyde cellulose gel membrane into a polyethyleneimine aqueous solution to perform grafting reaction, so as to obtain a polyethyleneimine grafted cellulose membrane; step 5, chloridizing the polyethyleneimine grafted cellulose membrane, so as to obtain the polyethyleneimine basedchloramines type antibacterial cellulose membrane. The preparation method is performed in an aqueous solution, reaction conditions are mild, the technology is simple to operate, and the preparation processes are environmentally friendly; the formed antibacterial cellulose membrane has good biocompatibility and breathability, and the antibacterial and bactericidal properties are excellent.

The invention relates to dialdehyde cellulose grafted epsilon-polylysine antibacterial material, prepared by oxidizing cellulose into dialdehyde cellulose, and using the dialdehyde cellulose as a supporter to modify with epsilon-polylysine under a certain aldehyde group molar ratio through grafting reaction so that epsilon-polylysine is grafted to dialdehyde microcrystalline cellulose. The processto prepare the dialdehyde cellulose grafted epsilon-polylysine antibacterial material is simple; the dialdehyde cellulose grafted epsilon-polylysine antibacterial material has no toxic and side effects and has good antibacterial activity; with penicillin acting as a positive control and LB (lysogeny broth) liquid medium as a negative control, the material herein has minimum inhibitory concentrations of 7.5 mg/mL, 15 mg/mL and 30 mg/mL respectively for E. coli and S. aureus, S. typhimurium, and S. lutea and B. subtilis. A new idea is provided for the research and development of novel antibacterial materials.

The invention discloses a preparation method of a cellulose and fibroin composite small-caliber artificial blood vessel material. The method is characterized by including the steps of hydrolyzing phyllostachys heterocycla pulp powder through cellulase, conducting oxidization through sodium periodate to prepare nanometer dialdehyde cellulose, and adding the nanometer dialdehyde cellulose to a fibroin solution for mixing reaction to establish the ideal small-caliber artificial blood vessel material. The blood vessel material comprehensively uses the high mechanical strength of nanocrystalline cellulose and the good adaptability and biocompatibility of silk fibroin and provides a data basis for finding a suitable small-caliber blood vessel substitute material. Meanwhile, silk and phyllostachys heterocycla resources in the province can be fully used for preparing a high-additional-value biological medical new material, and the method is expected to be an innovative concept for using silk and phyllostachys heterocycla resources in a high-valued mode, and conforms to the national development circular economy policy.

The invention belongs to the field of functional polymers and natural polymers, and particularly relates to a dialdehyde cellulose with a high aldehyde group content as well as a preparation method and application thereof. The invention provides a preparation method of dialdehyde cellulose with a high aldehyde group content. The preparation method comprises the following steps: (1) dissolving a cellulose raw material in a solvent to obtain a cellulose solution; and (2) adding an oxidizing agent into the cellulose solution to carry out reactions in the absence of light, and solidifying and forming in a coagulating bath to obtain the dialdehyde cellulose with a high aldehyde group content of 50-90%. According to the method, the reaction of the oxidized cellulose is carried out in a homogeneous solution of the cellulose, so that the reaction uniformity and the accessibility of an oxidizing agent to the cellulose are greatly improved; the method can efficiently prepare the dialdehyde cellulose with a high aldehyde group content, the yield can reach 95% or above, the product is uniform; the preparation process is simple, and industrialization is easy to realize.

The invention discloses a preparation method of a hyperbranched modified cellulose wood adhesive, which comprises the following steps: oxidizing microcrystalline cellulose (MCC) by sodium periodate to obtain dialdehyde cellulose (DAC), and further preparing the cellulose-based wood adhesive by taking the dialdehyde cellulose (DAC) and a hyperbranched polyamine compound as raw materials through Schiff base reaction. The hyperbranched modified cellulose wood adhesive is green and environment-friendly, free of formaldehyde release, high in bonding strength and good in water resistance when being used for plywood, and the performance of the hyperbranched modified cellulose wood adhesive is superior to that of the national standard GB/T 17657-2013. The invention aims to develop a novel cellulose-based biomass formaldehyde-free wood adhesive, and meanwhile, high-value and high-efficiency utilization of cellulose biomass resources is realized.

The present disclosure is directed to method of preparing an antimicrobial agent comprising heating a dialdehyde polysaccharide. The method comprises subjecting a dialdehyde polysaccharide, such as a dialdehyde starch or a dialdehyde cellulose, to heating and/or sonication for a period of time. Also provided herein is an antimicrobial composition comprising the prepared dialdehyde polysaccharide. The antimicrobial composition is effective at killing microbial agents such as viruses and bacteria within a short period of time.

The present invention relates to preparation of protein bamboo fiber; the protein bamboo fiber is prepared by grafting one or more of sericin, fibroin, collagen, keratin and soy protein on dialdehyde cellulose used as a substrate. Bamboo fiber can be endowed with physiological and biological activities by the protein bamboo fiber provided by the invention, which can not only expand the application field of bamboo fiber and improve wearability and added value of bamboo fiber, but also meet the requirements of ecological textiles without adding any chemical cross-linking agent.

A hemostatic textile material to stop bleeding comprising a dialdehyde cellulose (DAC) carrier wherein the degree of oxidation of the dialdehyde cellulose varies from about 1.5% to 12%; and a blood coagulation factor selected from the group consisting of chitosan and gelatin; the blood coagulation factor being chemically immobilized thereon; and further optionally comprising a bacteriolytic agent selected from the group consisting of a lysozyme enzyme, silver nitrate, and chlorhexidine; and further optionally comprising a selected component that prevents hemolysis, the component selected from the group consisting of tranexamic acid or ε-aminocaproic acid chemically immobilized thereon.

The invention discloses a preparation method of a dialdehyde cellulose cross-linked chitosan film, and belongs to the field of natural macromolecule modification. Microcrystalline cellulose is used as raw materials; water-soluble dialdehyde cellulose is respectively prepared through concentrated sulfuric acid hydrolysis and sodium periodate selective oxidization; then, the dialdehyde cellulose water solution is directly mixed with chitosan-acetic acid solution; vacuum defoaming and room temperature casting drying film formation are performed. Compared with a pure chitosan film, the dialdehyde cellulose cross-linked chitosan film prepared by the method provided by the invention has the advantages that the mechanical performance is obviously improved; the swelling degree in the water is obviously reduced.

The present invention discloses a method for preparing a formaldehyde-free fiberboard using dialdehyde cellulose and belongs to the technical field of fiberboard production. According to the invention, the dialdehyde cellulose is mixed with straw pellets under a condition of 160-190 DEG C for subsequent hot-pressing molding, where 0.5%-20% of dialdehyde cellulose and the balance of the straw pellets are used. According to the invention, the dialdehyde cellulose having highly active aldehyde groups is used as an adhesive to crosslink the straw pellets such that the prepared fiberboard is formaldehyde-free and has good physical properties. According to the invention, by using agricultural straws as the major raw materials instead of wood, resource waste and environmental pollution due to a large quantity of burnt agricultural straws in China may be effectively solved while the production cost is reduced. Furthermore, according to the invention, raw materials for synthesizing the dialdehyde cellulose are widely available and moderately priced, and a synthesis process for the dialdehyde cellulose is simple with short synthesis time, and thus is conducive to industrial production.

The invention discloses a beta-cyclodextrin-based functional cellulose fiber. The preparation method of the beta-cyclodextrin-based functional cellulose fiber comprises impregnating dialdehyde cellulose fiber in amino-beta-cyclodextrin solution at 60 DEG C for 30-60 min, and then repeatedly washing the impregnated dialdehyde cellulose fiber in a deionized mode, then impregnating the dialdehyde cellulose fiber inside beta-cyclodextrin solution at 60 DEG C for 30-60 min, repeatedly washing the impregnated dialdehyde cellulose fiber in a deionized mode and accordingly completing a dialdehyde cellulose fiber assembling process in the amino-beta-cyclodextrin solution and the beta-cyclodextrin solution; repeating the dialdehyde cellulose fiber assembling process in the amino-beta-cyclodextrin solution and the beta-cyclodextrin solution to obtain the beta-cyclodextrin-based functional cellulose fiber. The preparation method of the beta-cyclodextrin-based functional cellulose fiber overcomes the deficiency that conventionally grafting beta-cyclodextrin onto the surface of cellulose fiber requires non-environment-friendly crosslinking agents such as citric acid, ethylene diamine tetraaceticacid, epoxy chloropropane and glutaraldehyde; by controlling the number of times of beta-cyclodextrin assembly, the preparation method of the beta-cyclodextrin-based functional cellulose fiber can freely adjust the number of beta-cyclodextrin on the surface of the cellulose fiber.

The invention discloses cellulose nanoparticles and a preparation method thereof. Dialdehyde cellulose is generated by utilizing sodium periodate oxidized cellulose; the dialdehyde cellulose and aminereact to generate Schiff base; then the Schiff base is injected into water to generate the cellulose nanoparticles; the cellulose nanoparticles have good pH (Potential of Hydrogen) responsiveness andwide application.

The invention provides a preparation method and application of a cellulose-SiO2 composite carrier. The preparation method comprises the following steps: adding an ion solution into dialdehyde cellulose-SiO2 powder; stirring until the powder is dissolved, and centrifuging and de-foaming the solution to prepare a first fixed solution; cooling the first fixed solution to be 20 DEG C to 40 DEG C to prepare a second mixed solution, wherein the cooling time is 60 minutes to 120 minutes; preparing the second mixed solution into a liquid film with the thickness of 0.2mm to 1.0mm or micro-spheres with the diameter of 0.4mm to 1.2mm; putting the liquid film or the micro-spheres into an ethanol-water solution with the volume percent concentration of 15 percent and condensing; washing the condensed and molded thin film or micro-spheres with de-ionized water. The composite carrier provided by the invention has a self-cleaning function; after the composite carrier is used for a solidified enzyme, a lot of enzyme activity of free enzymes can be remained; the enzymes solidified on the composite carrier can be recycled and repeatedly utilized; the temperature sensitivity is greatly reduced when being compared with that of the free enzymes, and the composite carrier has the properties of stability and uneasiness of deactivating.

The invention relates to a leather tanning agent based on cellulose and nanometer SiO2 hybridization and a preparation method of a compound. The compound is obtained by dialdehyde cellulose and SiO2-NH2 through a Schiff's Base reaction; and the weight ratio of the dialdehyde cellulose to nanometer SiO2 particles is 2.0-4.0. The leather tanning agent is a clean, environment-friendly and ecological leather tanning agent product, and eliminates pollution of a chromium tanning agent. Meanwhile, a synergistic effect of modified cellulose and nanometer SiO2 can enhance the rigidity of a modified cellulose tanning unit and improve the water washing resistance of the nanometer SiO2 to finally raise the shrinkage temperature; and the surface over-tanning phenomenon caused by single use of the modified cellulose can be prevented, and the rough surface phenomenon caused by agglomeration by single use of nanometer SiO2 can be prevented, so that the crust leather grain surface is delicate.

The invention provides a method for preparing phytosterol ester from a nano composite magnetic material-immobilized lipase. Chitosan with a polysaccharide chain structure and rich functional groups wraps an outer surface of a magnetic nano material ferroferric oxide, and then dialdehyde cellulose with an excellent flexible structure and biocompatibility is used as macromolecule cross-linked molecules to covalently immobilize lipase activated by an ionic liquid type surfactant. The organic-inorganic magnetic nano composite material immobilized enzyme prepared by the method has characteristics of high catalytic activity, convenience in separation, good reusability and the like, and can be used for catalyzing esterification reaction of phytosterol and fatty acid to prepare phytosterol ester.The invention provides a green and efficient new method for synthesizing phytosterol ester.

The invention discloses a preparation method for a cellulose/chitosan compound anti-microbial adsorbent. The preparation method comprises the following steps: taking microcrystalline cellulose as a raw material; selectively oxidizing the microcrystalline cellulose, thereby acquiring dialdehyde cellulose; in-situ generating nanometer ZnO on the surface of dialdehyde cellulose through a hydrothermalprocess; compounding the dialdehyde cellulose loaded with nanometer ZnO with chitosan; freeze-drying, thereby acquiring the cellulose/chitosan compound anti-microbial adsorbent. The material has an excellent adsorptive property for heavy metal ions and dyestuffs, has antibacterial rate of 93.0%-99.9% to gram-positive bacterium and gram-negative bacterium and has an excellent anti-microbial property; the adsorbent can be widely used for treating various wastewater containing various heavy metal ions and dyestuffs; the preparation of the adsorbent is simple and the reaction condition is mild; the adsorbent has a broad application prospect in the field of sewage treatment.

The present invention relates to a sulfonated cellulose preparation method, which comprises that dialdehyde cellulose and a sulfonating agent are subjected to an addition reaction to prepare sulfonated cellulose, wherein the reaction medium of the addition reaction contains ethanol. According to the invention, a reaction medium containing ethyl alcohol is used for an addition reaction of dialdehyde cellulose and a sulfonating agent, so that the sulfonated cellulose can be easily separated from a reaction system even if the highly hydrophilic sulfonated cellulose is prepared from the dialdehydecellulose with the high aldehyde group content; and the yield of sulfonated cellulose is high by adopting the reaction medium containing ethanol.

The invention discloses a cellulose-based Schiff base fluorescent material as well as a preparation method and application thereof. Natural cellulose is used as a raw material, sodium periodate is used for oxidation to prepare dialdehyde cellulose, then the dialdehyde cellulose and 4-(4-dimethylaminophenyl)-8, 9, 9-trimethyl-5, 6, 7, 8-tetrahydro-5, 8-bridge methylene quinazoline-2-amine are subjected to a condensation reaction, and the cellulose-based Schiff base fluorescent material is prepared. The raw materials are rich in source and low in price, the prepared cellulose-based Schiff base fluorescent material is high in fluorescence intensity, blue fluorescence is generated under ultraviolet irradiation, the fluorescence color of the material is gradually changed into green from blue within the pH range of 1-7, and the cellulose-based Schiff base fluorescent material can be used for detecting pH under the acid condition and has good application prospects.

The invention provides a hyperbranched cellulose crown ether and a preparation method thereof. The preparation method comprises the steps that first, cellulose is oxidized into dialdehyde cellulose; then, aldehyde groups on the dialdehyde cellulose react with polyethyleneimine to prepare hyperbranched cellulose rich in amino; and finally 4-formyl benzo-15-crown ether-5 reacts with the amino of thehyperbranched cellulose to prepare the hyperbranched cellulose crown ether. The hyperbranched cellulose crown ether has the beneficial effects that the hyperbranched cellulose is rich in amino groups, the load of a crown ether active group can be improved, and meanwhile, the hyperbranched crown ether group is further beneficial to the adsorption of heavy metal ions.

The invention discloses a dialdehyde cellulose-based Schiff base fluorescent probe for detecting Al<3+>, and a preparation method and application thereof. The preparation method comprises the following steps: by taking dialdehyde cellulose as a raw material, carrying out condensation on dialdehyde cellulose and sebacic dihydrazide to prepare dialdehyde cellulose-sebacic dihydrazide mono-Schiff base; and further carrying out condensation on the dialdehyde cellulose-sebacic dihydrazide mono-Schiff base and 2-hydroxy-1-naphthaldehyde, so as to prepare the dialdehyde cellulose-sebacic dihydrazide 2-hydroxy-1-naphthaldehyde bis-Schiff base. Under the irradiation of 365 nm ultraviolet light, after Al<3+> is added into a DMF suspension of dialdehyde cellulose-sebacic hydrazide-2-hydroxy-1-naphthaldehyde bis-Schiff base, the fluorescence color of the solution is changed from colorless to blue, the detection limit of Al<3+> reaches 6.06 * 10<-7> M, and the fluorescent probe for detecting Al<3+> ions has a good application prospect as a fluorescent probe for detecting Al<3+> ions.