22 results about "Crosslinked chitosan" patented technology

The application provides a long-acting, non-embolism filling monodisperse chitosan microsphere, the base material of the microsphere is cross-linked chitosan, the cross-linked chitosan is formed by cross-linking reaction of component A and a cross-linking agent, or formed by cross-linking reaction of component A, component B and the cross-linking agent; the component A is at least one of chitosan and modified chitosan, and the component B is at least one of hyaluronic acid, collagen and gelatin; the particle size of the microsphere is 20-120 mu m, and the variation coefficient of the microsphere particle size is not more than 5%. The application also provides a preparation method of the microsphere. The monodispersity of the microsphere is excellent, the degradation time is relatively longer, the water absorption performance is good, the embolism risk can be reduced, the filling effect maintaining time can be prolonged, and the effect of improving wrinkles can be increased, and the problems of short filling effect maintaining time and easy to cause blood vessel embolism of the filling hyaluronic acid product used in the existing medical and beauty field can be solved.

The present invention describes capsule compositions consisting of crosslinked chitosan, beta-glucan or alginate, and encapsulates an environmentally compatible ingestible larvicide, especially larvicidal agents such as essential oils or other ingestible larvicides such as Bacillus thuringiensis which are lethal to the larvae of pest insects, especially mosquito larvae.

The application discloses a finishing method of chitosan fiber and chitosan fiber prepared by the method, and comprises the following steps: preparing an acid aqueous solution of an anionic polyelectrolyte, adding a crosslinking agent and stirring uniformly, pre-crosslinking, and obtaining a pre-crosslinked chitosan fiber finishing solution; immersing formed chitosan fiber into the pre-crosslinked chitosan fiber finishing solution for soaking, drying and heat-crosslinking, and immersing into ethanol, and obtaining finished chitosan fiber. The application utilizes the property that chitosan fiber is activated into a cationic electrolyte under an acid condition, and an anionic polyelectrolyte is strongly adsorbed on the surface of the chitosan fiber through electrostatic interaction, effectively solves the problem that the interaction force between a sizing agent and other finishing agents and the chitosan fiber is weak, and effectively avoids the problem that the mechanical property of the chitosan fiber is poor due to the falling-off of the finishing agents and the sizing agent during use.

The invention belongs to the technical field of biology, and particularly relates to a bacteriostatic agent and a preparation method and application thereof. Comprising the following steps that antibacterial peptide modified silver nanoparticles are prepared, specifically, antibacterial peptide and silver nitrate grow in situ under the action of a reducing agent, and the antibacterial peptide modified silver nanoparticles are obtained; preparing a bacteriostatic agent: dissolving the antibacterial peptide modified silver nanoparticles by using a cross-linked substance of chitosan and dextran sulfate to obtain the bacteriostatic agent; the charge of the cross-linked substance of the chitosan and the dextran sulfate is 0. Through mutual attraction of positive charges of the antibacterial peptide and negative charges of the silver nanoparticles, the silver nanoparticles wrapped by the antibacterial peptide are formed, the self-assembly or irregular agglomeration behavior of the antibacterial peptide is effectively controlled, a nanometer network formed by crosslinking chitosan with dextran sulfate can stabilize the nanometer form of the silver nanoparticles, and the antibacterial activity of the antibacterial peptide is improved. The core-shell structure formed by the silver nanoparticles wrapped by the antibacterial peptide can be stabilized, the silver nanoparticles wrapped by the antibacterial peptide can also be dispersed, and mutual agglomeration of the core-shell structure is prevented.

The invention belongs to the field of functional materials and water treatment, and provides a preparation method of organic phosphonic acid functionalized super-crosslinked chitosan hydrogel, which comprises the following steps: dissolving chitosan in an alkali solution to obtain a chitosan suspension; adding benzaldehyde into the chitosan suspension, and carrying out condensation reaction to obtain a modified chitosan suspension; reacting the modified chitosan suspension with a quinary organic phosphonic acid solution to obtain an organic phosphonic acid functionalized chitosan solution; adding a potassium tripolyphosphate solution into the organic phosphonic acid functionalized chitosan solution, carrying out a cross-linking reaction, carrying out alcohol precipitation after the reaction is completed, carrying out solid-liquid separation, and collecting a precipitate; dispersing the precipitate in water to obtain a suspension; and uniformly mixing the suspension with a sodium alginate solution and a calcium salt solution, and carrying out a cross-linking reaction to obtain the quinary organic phosphonic acid functionalized super-crosslinked chitosan hydrogel. An organic phosphonic acid group and a C-P covalent bond are successfully introduced into a chitosan molecular chain, the morphology structure of original chitosan powder is greatly improved, adsorption sites on the chitosan molecular chain are enriched, and efficient application of chitosan in uranium-containing wastewater is remarkably improved.

The application belongs to the technical field of pharmaceutical preparations, and particularly relates to a diclofenac sodium enteric-coated tablet and a preparation method thereof. The diclofenac sodium enteric-coated tablet comprises a quick-release layer, a slow-release layer and an enteric-coated layer; the quick-release layer comprises the following components in parts by weight: 20-40 parts of diclofenac sodium, 5-15 parts of a disintegrating agent, 20-50 parts of a filling agent, 1-3 parts of a lubricant and 1-5 parts of a binder; the slow-release layer comprises the following components in parts by weight: 50-80 parts of diclofenac sodium, 5-15 parts of crosslinked chitosan, 1-3 parts of a lubricant and 1-5 parts of a binder; and the enteric-coated layer comprises the following components in parts by weight: 20-45 parts of an enteric material and 5-15 parts of N-acetylneuraminic acid derivative. The diclofenac sodium enteric-coated tablet has excellent in-vitro cumulative release degree, and has low hygroscopicity, high stability and high friability.

The present application relates to the field of environmental microorganism and wastewater treatment technology, and specifically discloses a kind of fermentation microbial inoculum for sewage treatment and application.The fermentation microbial inoculum is made by immobilizing multifunctional composite microbial inoculum on chitosan magnetic microspheres;The multifunctional composite microbial inoculum is compounded by the fermentation broth of Pseudomonas koreensis, Lactobacillus acidophilus, Brevibacillus brevis, Timumasidium and Bacillus licheniformis according to a specific viable count ratio.The chitosan magnetic microspheres have Fe3O4 as magnetic core and are coated with crosslinked chitosan layer.The present application successfully constructs a microbial repair system with functional complementation and easy recovery by combining specific flora compounding with magnetic immobilization technology.The microbial inoculum can efficiently and synchronously remove nitrate, tetrabromobisphenol A and heavy metal multi-component pollutants in groundwater or contaminated water bodies, and can be quickly recovered and reused by external magnetic field, with the advantages of high treatment efficiency, environmental friendliness and low cost.

The subject matter described herein relates to crosslinked chitosan hydrogels having desirable properties and methods of making and using the same.

The application provides a hollow mesoporous silica (BTA@HMSNs-CS) material for metal material targeted corrosion inhibition and Pickering emulsion stabilization in an oil production well, a preparation method and an application. The material selects hollow mesoporous silica (HMSNs) as a nano container for loading corrosion inhibitors, cross-linked chitosan (CS) as a pH response valve for controlling corrosion inhibitor release and reducing interfacial tension to form a Pickering emulsion. The BTA@HMSNs-CS is assembled from an acid response cross-linked CS network and a large cavity HMSNs, the preparation method is simple and easy to implement, has good acid response and emulsion stabilization performance, and has great reference value and application prospect in the field of downhole metal corrosion prevention and emulsion stabilization.

The application belongs to the technical field of rare earth recovery, and particularly relates to a modified chitosan adsorbent for recovering scandium and a preparation method thereof, which comprises the following steps: (1) preparing a chitosan-acetic acid mixed solution, dropping the mixed solution into a NaOH solution, filtering off the alkali solution after soaking and solidifying, and cleaning the solid with deionized water until the filtrate is neutral to obtain a spherical gel; (2) adding a pre-crosslinking agent to the spherical gel, oscillating or stirring, filtering off the liquid, and washing the solid multiple times to obtain pre-crosslinked chitosan; (3) adding deionized water to the pre-crosslinked chitosan, mixing uniformly, then dropping in a crosslinking agent, oscillating until sufficient crosslinking is achieved, filtering off the liquid, and washing the solid to obtain the solid; (4) adding an ethanol solution and an amination reagent to the solid, oscillating or stirring, filtering off the liquid, and washing the solid to obtain polyaminated chitosan; and (5) uniformly mixing a solvent, the polyaminated chitosan, a phosphinic acid and an inorganic acid, heating, adding a formaldehyde solution, constant-temperature reaction, extraction, and removing the solvent to obtain the modified chitosan adsorbent.

This invention belongs to the field of clarifier technology, specifically relating to an environmentally friendly swimming pool water clarifier based on modified chitosan. It is formed by grafting and crosslinking chitosan with 2-acrylamido-2-methylpropanesulfonic acid and vinylimidazole using an initiator and a crosslinking agent. This invention uses AMPS and VIM to double-graft modify chitosan, giving the product excellent flocculation and turbidity removal, flocculation and algae removal, chlorine resistance, and wide pH adaptability. At a dosage of 5 mg / L, the turbidity removal rate reaches 96.2%, and the algae cell removal rate reaches 93.5%, demonstrating comprehensive performance superior to existing products such as unmodified chitosan, polyaluminum chloride, and cationic polyacrylamide.

The invention relates to the technical field of environmental microorganisms and wastewater treatment, and particularly discloses a fermentation inoculant for sewage treatment and application. The fermentation inoculant is prepared by immobilizing a multifunctional composite inoculant on chitosan magnetic microspheres, the multifunctional complex microbial inoculant is prepared by compounding fermentation broth of pseudomonas koreensis, lactobacillus acidophilus, bacillus brevis, massinia pemophila and bacillus licheniformis according to a specific viable count ratio, wherein the fermentation broth of the pseudomonas koreensis, the lactobacillus acidophilus, the bacillus brevis, the massinia pemophila and the bacillus licheniformis are used as raw materials. Fe3O4 is used as a magnetic core of the chitosan magnetic microsphere, and a cross-linked chitosan layer is coated outside the magnetic core. Through combination of specific flora compounding and a magnetic immobilization technology, a microbial remediation system which has complementary functions and is easy to recover is successfully constructed. The microbial agent can efficiently and synchronously remove nitrate, tetrabromobisphenol A and heavy metal multi-component composite pollutants in underground water or polluted water, can be quickly recycled and reused through an external magnetic field, and has the advantages of high treatment efficiency, environment friendliness and low cost.

The invention relates to a preparation method of euphausia superba oil with high phospholipid content. The preparation method comprises the following steps: mixing and soaking euphausia superba powder and absolute ethyl alcohol in proportion; carrying out counter-current extraction for 60-90 minutes once, and then carrying out counter-current extraction for 40-80 minutes by using absolute ethyl alcohol to obtain an euphausia superba oil ethanol solution and a solid phase; the passing temperature of the solid phase is 50-80 DEG C, the vacuum degree is 0.1-1.0 Mpa, and ethanol is evaporated, condensed and collected; further dehydrating the ethanol to prepare absolute ethyl alcohol for recycling; adding the euphausia superba oil ethanol solution into the attapulgite composite cross-linked chitosan microspheres, stirring and dispersing for 120-180 minutes, filtering and recovering the attapulgite composite cross-linked chitosan microspheres, and then recovering ethanol under reduced pressure to obtain the euphausia superba oil with high phospholipid content. According to the method, the euphausia superba oil with high phospholipid content is obtained by combining an absolute ethyl alcohol counter-current extraction technology with the attapulgite composite cross-linked chitosan microspheres, and the method has a relatively great application prospect and market.

The invention discloses a preparation method of photo-crosslinked chitosan-based composite hydrogel microspheres based on a microfluidic technology, and belongs to the technical field of biomedical materials. The preparation method comprises the following steps: reacting methacrylic anhydride with chitosan to obtain double-bond chitosan; the preparation method comprises the following steps: reacting lipoic acid with chitosan to obtain lipoic acid modified chitosan; the preparation method comprises the following steps: mixing double-bond chitosan with lipoic acid modified chitosan to obtain an aqueous solution of chitosan, adding tris (2-carbonyl ethyl) phosphorus hydrochloride, poloxamer F-127, a photoinitiator, dopamine and methyl hesperidin, and then performing stirring and centrifugal defoaming treatment to obtain a composite hydrogel precursor solution; and preparing the composite hydrogel precursor solution into composite hydrogel microspheres by using a microfluidic technology and a photocuring technology. The hydrogel microspheres prepared by the invention can effectively promote cell adhesion, and have good biocompatibility, water-retaining property and mechanical compressibility.

This invention belongs to the field of resource recycling and water treatment agent technology, and more specifically, relates to a cationic chitosan fiber, its preparation method, and its application. The present invention provides a cationic chitosan fiber with a cross-sectional size in the micrometer range. First, chitosan fibers are mixed with a cross-linking agent to undergo a cross-linking reaction, transforming the linear chitosan molecular structure in the chitosan fibers into a three-dimensional network structure of cross-linked chitosan fibers. Then, the cross-linked chitosan fibers are mixed with a quaternary ammonium salt cationic modifier for modification, so that the quaternary ammonium groups are fixed on the cross-linked chitosan fibers, thus preparing the cationic chitosan fiber. The quaternized cationic chitosan fiber prepared by this invention has a positive effect on Au(CN)2. ‑ The adsorption rate is extremely fast. Furthermore, the quaternized cationic chitosan fibers prepared in this invention exhibit excellent adsorption of Au(CN)₂ in an alkaline environment. ‑ Its adsorption capacity can reach up to 669.8±47.2 mg / g, which is much higher than that of the adsorbents reported so far.

The application relates to the technical field of renewable bioenergy, in particular to an enzyme catalysis synchronous desulfurization process for preparing bio-diesel from kitchen waste oil, which comprises the following steps: putting pretreated kitchen waste oil, immobilized lipase, a cross-linked chitosan porous microsphere composite adsorbent loaded with zinc oxide and iron oxide and methanol into the same reactor, and performing one-pot ester exchange reaction under the condition of 40-50 DEG C through the mode of step-by-step addition of methanol, so that deep desulfurization is synchronously completed in the reaction process, that is, the core contradiction that the existing desulfurization scheme cannot be applied to the one-pot process due to the incompatibility with the enzyme is solved.

The invention provides a conductive heterojunction catalyst, a preparation method and a catalytic reaction device. The preparation method comprises the following steps: adding a molecular sieve into a mixed solution of a cationic polymer and a sulfonic acid group-containing anionic polyelectrolyte, and mixing to obtain a modified molecular sieve; chitosan and the modified molecular sieve are subjected to crosslinking treatment, a composite material is obtained, the composite material is sintered in a protective atmosphere, and the conductive heterojunction catalyst is obtained. The conductive heterojunction catalyst obtained by the preparation method provided by the invention is high in conductivity, excellent in catalytic performance and stable in structure, and can be used for converting electric heat into energy supply for reaction and reducing carbon emission.

In various embodiments, the present invention relates to a method of treating or preventing bleeding at a tissue site comprising applying a chitosan powder composition to the tissue site.SOLUTION: In various aspects, the invention relates to a chitosan powder composition for application to a tissue site, the powder composition comprising a chitosan salt, a cross-linked chitosan, a derivatized chitosan, or a combination thereof. In various aspects, the present invention relates to a catheter assembly pre-loaded with a chitosan powder composition and configured to deliver the chitosan powder composition to a tissue site.SELECTED DRAWING: None

The invention discloses a slow-release algae-controlling agent suitable for filamentous cyanobacterial bloom and a preparation method and application thereof. The slow-release algae-controlling agent is a coated pellet with potassium persulfate as a core and a Ca ion crosslinking chitosan network as a shell layer. Wherein the particle size of the coated small balls is 1.5 mm to 2.0 mm; and the thickness of the shell layer is 10-30 [mu] m. In the slow-release algae control agent, potassium persulfate serves as an algae inhibition active substance, a Ca ion cross-linked chitosan network shell layer can flocculate filamentous blue-green algae with negative electricity in a targeted mode, and the filamentous blue-green algae is specifically inhibited through a dual synergistic mechanism of potassium persulfate free radical oxidation and shell layer targeted flocculation.

The invention belongs to the technical field of pharmaceutical preparations, and particularly relates to a diclofenac sodium enteric-coated tablet and a preparation method thereof. The diclofenac sodium enteric-coated tablet comprises a quick release layer, a slow release layer and an enteric coating layer, the quick release layer comprises the following components in parts by weight: 20-40 parts of diclofenac sodium, 5-15 parts of a disintegrating agent, 20-50 parts of a filling agent, 1-3 parts of a lubricating agent and 1-5 parts of an adhesive; the sustained release layer comprises the following components in parts by weight: 50-80 parts of diclofenac sodium, 5-15 parts of cross-linked chitosan, 1-3 parts of a lubricant and 1-5 parts of an adhesive; the enteric coating layer is prepared from the following components in parts by weight: 20 to 45 parts of enteric material and 5 to 15 parts of N-acetylneuraminic acid derivative. The diclofenac sodium enteric-coated tablet disclosed by the invention has excellent in-vitro accumulative release rate, relatively low hygroscopicity and relatively high stability and friability.

The present application belongs to the field of sludge treatment, and provides a self-gelling dewatering agent for low-organic-matter sludge, a preparation method and application thereof. The self-gelling dewatering agent comprises 90-110 parts of ferrous sulfate, 20-70 parts of slag, 20-70 parts of fly ash, 10-60 parts of modified bentonite and 10-60 parts of crosslinked chitosan by mass fraction. The slag is one or both of blast furnace slag or yellow phosphorus slag; the modified bentonite is hydrochloric acid-activated bentonite. The yellow phosphorus slag is acidified yellow phosphorus slag. The dewatering agent provided by the present application solves the problem of single function of traditional solid agents by using waste to treat waste, and can realize multifunctional synergy of promoting sludge dewatering and fixing heavy metals and sulfides by one-time addition.

The invention belongs to the field of materials, and particularly relates to an impact-resistant flame-retardant gas gel material and a preparation method thereof. The invention aims to solve the problems that the protective material is light in weight, and impact resistance and flame retardance are difficult to consider at the same time. The preparation method comprises the following steps: (1) preparing a chitosan-organic acid solution; (2) adding sodium tripolyphosphate, and preparing bi-crosslinked chitosan aerogel by using an ice crystal template method; (3) mixing high-viscosity polydimethylsiloxane and low-viscosity polydimethylsiloxane; (4) adding boric acid to prepare shear hardening gel; and (5) performing ultrasonic impregnation and drying to obtain the product. And the obtained product is light in weight, excellent in impact resistance (the impact peak force of a falling ball of 80cm is less than or equal to 580N), capable of self-extinguishing, and suitable for the high-end engineering fields such as aerospace, national defense and military, electronic and electrical appliances, new energy and the like.