1387 results about "Chemical modification" patented technology

The invention provides a polyaniline / modified graphene oxide composite material and a preparation method thereof. The preparation method comprises the following steps: dispersing purified graphene oxide, performing ultrasonic treatment, heating, adding a modifier for modification, centrifuging, taking precipitate, freezing, drying and grinding to obtain modified graphene oxide powder; mixing the powder with an aniline solution in doped acid to form a modified graphene oxide / aniline acid solution; dissolving ammonium persulfate in the doped acid to prepare an ammonium persulfate acid solution; and slowly dropwise adding the solution into the solution, carrying out in-situ polymerization, and carrying out suction filtration, washing and drying to obtain the composite material. According to the method, through chemical modification and in-situ polymerization processes, the problems that a single filler is poor in dispersity, a conductive network is discontinuous, and anti-corrosion and anti-static performance is difficult to synergistically improve are solved, and the process is simple and convenient and suitable for industrialization.

The invention relates to a high-strength stable solid waste-based composite cementing material and a preparation method and application thereof in the field of building materials. The high-strength stable solid waste-based composite cementing material is prepared from the following raw materials in parts by weight: 70-85 parts of composite solid waste micro powder; 10 to 20 parts of Portland cement clinker; 3-8 parts of a composite activator; 0.5 to 2 parts of a nano-scale function regulator; wherein the composite solid waste micro powder is prepared by mixing and grinding the following raw materials in parts by weight: 40-60 parts of blast furnace slag powder; 20 to 30 parts of fly ash; 10-20 parts of chemically modified electrolytic manganese residue powder; and 5-15 parts of steel slag powder. According to the preparation method, sodium metasilicate is adopted to assist medium-temperature calcination to chemically modify the electrolytic manganese residues, so that not only is the gelation activity of the electrolytic manganese residues effectively excited, but also free-state manganese, cadmium and other heavy metal ions in the electrolytic manganese residues are fixed in situ in newly formed zeolite-like silicate mineral lattices through thermochemical reconstruction; and a brand new technical path is opened up for safe and high-value utilization of the typical hazardous waste, namely the electrolytic manganese residues.

Among other things, the present disclosure provides oligonucleotide compositions and methods thereof. In some embodiments, oligonucleotides comprise various chemical modifications. In some embodiments, the present disclosure provides technologies useful for manufacturing oligonucleotides.

The invention belongs to the technical field of organic matter preparation, and discloses an amide-containing isoxazoline derivative as well as a preparation method and application thereof. According to the invention, chemical modification and molecular design are carried out on the compound with an isoxazoline structure, and a substituent group is introduced to N of an amide group, so that a series of efficient compounds which can be used for killing insects or mites in agriculture or forestry and have excellent activity are obtained, and particularly, the compounds have very good biological activity on lepidoptera, hemiptera and other pests. When being used at an extremely low concentration, the compound disclosed by the invention also shows an excellent control effect on various pests or pest mites, has insecticidal or acaricidal activity in each stage (such as eggs, larvae (nymphs), pupae and adults) of the life cycle of the pests or pest mites, and has an excellent control effect on the pests or pest mites which have drug resistance to traditional insecticides or acaricides. And the composition also shows excellent control activity.

The present disclosure features useful oligonucleotide compositions and methods related thereto. The present disclosure encompasses the recognition that structural elements of oligonucleotides, such as base sequence, chemical modifications (e.g. modifications of sugar, base and / or internucleotide linkages) or patterns thereof, can have a significant impact on oligonucleotide properties and activities. The present disclosure also provides methods to treat disorders for which deamination of an adenosine in an mRNA produces a therapeutic result, e.g., in a subject in need thereof.

The invention relates to a laser processing method for a coated armor structure of wear-resistant super-hydrophobic aluminum bronze, which comprises the following steps of: preparing an aluminum bronze workpiece, polishing and cleaning, depositing a ceramic wear-resistant film on the surface of the workpiece by adopting pulse laser, and etching the ceramic wear-resistant film by adopting femtosecond laser, so as to obtain a coated armor structure of the wear-resistant super-hydrophobic aluminum bronze. And then chemical modification of the wear-resistant armor structure is completed through heat treatment, chemical modification of the micro-nano surface structure is completed, and the wear-resistant super-hydrophobic aluminum bronze is obtained. The wear-resistant ceramic film and the wear-resistant armor structure can resist wear together, double guarantee is provided for the internal hydrophobic microstructure, the super-hydrophobic wear resistance of the surface of a component in underwater equipment can be improved, the service life of the component can be prolonged, and the problem of marine organism corrosion is solved.

A method for visible light-mediated chemical modification of a polypeptide or protein based on cysteine includes the following steps: allowing a cysteine residue on a cysteine-containing oligopeptide, polypeptide, or protein to undergo a reaction with an activating reagent to generate a free radical precursor in situ; and subjecting the free radical precursor to desulfurization under photocatalytic condition, and allowing the generated free radical intermediate to undergo an addition reaction with an olefin or an alkyne, such that sulfhydryl removal and carbon-carbon bond construction are achieved to produce a chemical modification product of the polypeptide and protein. The method cleverly avoids the influence on the chiral center, and thus the chirality of the amino acid residue can be retained. The method is conducive to well avoiding the occurrence of side reactions, and thus the efficiency of the entire conversion is very high.

The invention discloses a silane cross-linked polyolefin halogen-free flame-retardant cable material and a low-energy-consumption preparation method thereof.The preparation method comprises the steps that EVA / EEA serves as a matrix, silane groups are covalently connected to a polyolefin molecular chain through a free radical grafting reaction, and a grafting material containing an active silane side group is prepared; meanwhile, vinyl isocyanate is adopted to chemically modify hydroxyl on the surface of magnesium hydroxide, vinyl is grafted to the surfaces of particles, the polarity of the particles is reduced, and the dispersity of the particles is enhanced; then carrying out melt blending on the grafted material and modified magnesium hydroxide, constructing an interface bridge by using an anhydride group, and shortening the two-phase distance; finally, through room-temperature natural cross-linking and warm water auxiliary cross-linking, silane groups are promoted to be hydrolyzed into silanol, the silanol is condensed to form a-Si-O-Si-three-dimensional network, meanwhile, vinyl on the surface of magnesium hydroxide and a polyolefin matrix are subjected to free radical copolymerization, and a covalent bond interface layer is formed between inorganic particles and an organic matrix. According to the method, the synergistic improvement of high crosslinking degree, strong stretchability and excellent flame retardance of the cable material is realized through molecular-level interface regulation and cross-linking network optimization.

The invention belongs to the field of solid waste recycling, and relates to a hematite modified rice hull-based biochar material as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out ultrasonic treatment on rice husks in an ethanol solution, then soaking the treated rice husks in a mixed solution of methanol and formalin for activation, carrying out vacuum filtration and drying, and carrying out anaerobic calcination under the protection of a nitrogen atmosphere to obtain rice husk-based biochar; the method comprises the following steps: soaking rice husk-based biochar in an acid solution, and carrying out microwave digestion on the acid-modified rice husk-based biochar to obtain chemically-modified rice husk-based biochar; adding into a solution containing ferrous sulfate, fully stirring, and then carrying out hydrothermal treatment to obtain the hematite modified rice hull based biochar material. The method can significantly improve the conversion rate of organic matters in the sludge, increase the accumulated yield of biogas, effectively reduce the biotoxicity of heavy metals in the sludge, facilitate the resource utilization of the sludge, and have important significance for solving the environmental risk problem of the sludge.

The invention relates to the technical field of engineering plastics, and discloses a polydicyclopentadiene / carbon nanofiber composite material and a preparation method and application thereof.The method comprises the steps that DCPD, ENB and MNA are mixed to be uniform, CNF is added and subjected to ultrasonic dispersion, a Grubbs second-generation catalyst is added and subjected to ultrasonic dispersion after freezing, finally, mixed liquid is poured into a mold, and the polydicyclopentadiene / carbon nanofiber composite material is obtained. And heating and curing to obtain the high-performance PDCPD / CNF composite material. According to the preparation method, the interaction between PDCPD and CNF can be remarkably improved, so that the mechanical property of the composite material is improved, the used raw material DCPD has low viscosity and high reaction activity, and rapid forming can be realized; meanwhile, the whole production process of the modified PDCPD composite material is green and environment-friendly, the process is simple, complicated chemical modification is not involved, and the feasibility of large-scale industrial production is achieved.

The invention discloses a double-response collagen-based conductive hydrogel, a medicine and a preparation and application method of the double-response collagen-based conductive hydrogel. The preparation method of the double-response collagen-based conductive hydrogel comprises the following steps: carrying out chemical modification on polysaccharide through 3-aminophenylboronic acid, and then carrying out sodium periodate oxidation treatment to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer; the preparation method comprises the following steps: performing hydrazide modification on collagen through adipic acid dihydrazide, and performing free radical polymerization with aniline to obtain a hydrazide collagen grafted polyaniline copolymer; the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer are subjected to crosslinking, and the double-response collagen-based conductive hydrogel capable of responding to glucose and the pH value is obtained. Compared with single-response conductive hydrogel, the hydrogel can specifically respond to the microenvironment of chronic diabetic wound surfaces and release antibacterial and anti-inflammatory drugs, and high-quality healing of chronic wounds such as diabetic foot ulcers and the like is promoted.

The invention relates to the technical field of high-temperature-resistant and high-thermal-conductivity epoxy electronic packaging adhesives, discloses a preparation method of a core-shell Al2O3-coated SiO2 filler and application of the core-shell Al2O3-coated SiO2 filler in epoxy packaging, and designs the preparation method of the core-shell structure filler Al2O3-coated SiO2 by chemically modifying the surface of the Al2O3 filler through high-temperature-resistant SiO2. The high-temperature-resistant SiO2 shell layer is modified on the surface of Al2O3, so that the interface wettability between the epoxy resin and the filler is promoted, the binding force between the filler and the epoxy resin is increased, the dispersity and fluidity of EMC are improved, meanwhile, the 175-DEG C bending strength of the epoxy resin is improved, and the high-temperature usability of the epoxy resin is greatly improved. And finally, the core-shell structure Al2O3-coated SiO2 can easily form a heat-conducting path among the filler, the interface and the matrix resin, so that the overall heat-conducting property of the composite material is improved, the low thermal expansion coefficient of the SiO2 shell layer is improved, the thermal stress is buffered, the temperature resistance is improved, and the core-shell structure Al2O3-coated SiO2 can be widely applied to packaging of semiconductor integrated circuits.

The invention discloses an information storage method based on DNA (deoxyribonucleic acid) coding, which comprises the following steps: converting digital information to be stored into a quaternary code, converting the quaternary code into a DNA sequence consisting of adenine A, cytosine C, guanine G and thymine T according to a preset mapping rule, and expressing an additional information dimension by using a chemical modification state of a nucleotide pair; inserting error detection and correction codes in the DNA sequence every a predetermined number of basic group positions, segmenting the encoded DNA sequence into a plurality of fragments with the length of 100-150bp, and adding a specific recognition sequence and an index marker at two ends of each fragment; a reversible thermosensitive response DNA nanostructure is used as a carrier, DNA fragments are selectively combined to the carrier, and hierarchical storage and rapid retrieval of information are realized through a temperature gradient control system; the DNA storage information density can be remarkably improved, the service life of DNA storage can be remarkably prolonged, and a novel technical path is provided for large-scale, long-term and safe molecular information storage.

The invention belongs to the technical field of polyurethane waterproof coatings, and particularly relates to a single-component fluorine-free high-hydrophobicity polyurethane waterproof coating and a preparation method thereof, and the single-component fluorine-free high-hydrophobicity polyurethane waterproof coating comprises the following raw materials by weight: 60-80 parts of composite polyether polyol; 20 to 40 parts of silane modified polyether polyol; 11 to 17 parts of diisocyanate; 2-5 parts of a chain extender; 50 to 70 parts of a plasticizer; 50 to 70 parts of filler; 0.15 to 0.2 part of a catalyst; and 3-5 parts of an auxiliary agent. A polyoxypentene ether chain segment, a castor oil-based structure and a silane group are introduced into the molecular structure of the waterproof coating through chemical modification, the intrinsic hydrophobic and mechanical properties of the material are improved, the migration defect caused by addition of a hydrophobic agent and silicone oil in a traditional preparation method is overcome, and the invention further provides a preparation method of the waterproof coating.

The invention belongs to the technical field of novel adsorption materials, and particularly relates to needle-punched cloth for extracting uranium from seawater based on dry-process PAN fibers and a preparation method and application of the needle-punched cloth. The needle-punched fabric for extracting uranium from seawater comprises chemical modified functional fibers and supporting fibers, the chemically modified functional fiber with amidoxime groups is obtained by chemically modifying a dry polyacrylonitrile short fiber. The invention discloses the needle punched cloth for extracting uranium from seawater based on the dry PAN fiber for the first time, the material has the advantages of low production cost, batch production and large-scale implementation, can be directly soaked in seawater, can be rolled into components such as a filter element and the like, and can be used for enriching and separating uranium from seawater in forms of single-layer filtration, multi-stage filtration and the like; the industrial popularization and application are easy.

The invention belongs to the field of oilfield chemistry, and discloses development and a method of a gel breaker for recycling drilling fluid, and the preparation method comprises the following steps: (1) contacting chitosan with a modifier under an alkaline condition for chemical modification to obtain O-carboxymethyl chitosan; and (2) carrying out radical polymerization on the obtained O-carboxymethyl chitosan and a quaternary ammonium salt monomer in an acid environment under the action of an initiator to obtain the gel breaker.

The invention belongs to the technical field of biological medicine, and discloses fluorine-containing modified poly-sarcosine acidified lipid as well as a preparation method and application thereof. The fluorine-containing modified poly-sarcosine acidified lipid disclosed by the invention has a structural general formula as shown in a formula (I) or a formula (II). The fluorine-containing modified poly-sarcosine acidified lipid obtained by chemically modifying the poly-sarcosine acidified lipid through different fluorine-containing groups can replace PEGylated lipid to prepare lipid nanoparticles (LNP), and is used for loading drugs such as nucleic acid and the like, so that the purpose of improving the drug delivery performance is achieved.

To provide a pressure-sensitive adhesive sheet capable of suppressing heavy peeling even when using an aqueous pressure-sensitive adhesive composition.SOLUTION: A pressure-sensitive adhesive sheet according to an embodiment of the present invention includes: a base material; and a pressure-sensitive adhesive layer formed of a water-dispersible pressure-sensitive adhesive composition containing a water-dispersible polymer, wherein a surface concentration of a carboxyl group on a surface of the pressure-sensitive adhesive layer obtained by an X-ray photoelectron spectroscopy (ESCA) gas phase chemical modification method is a detection limit value or less.SELECTED DRAWING: Figure 1

The invention relates to the technical field of textile, in particular to a xylitol-containing plant-source composite ultra-short fiber and a preparation method thereof.The xylitol-containing plant-source composite ultra-short fiber comprises an ultra-short fiber base material and plant-source functional particles, the plant-source functional particles are obtained by conducting chemical modification, microencapsulation and nanocrystallization treatment on citramalic acid, xylitol and plant-source extracts, and the plant-source functional particles are prepared from the ultra-short fiber base material and the plant-source extracts. According to the present invention, the heat absorption characteristic of xylitol is utilized to achieve the contact cool feeling effect, the antibacterial components of the plant source extract are adopted to form the antibacterial barrier so as to prevent the growth and the reproduction of bacteria and achieve the antibacterial effect, and the stability of the functional components is significantly enhanced through the chemical modification of citramalic acid; microencapsulation and nanocrystallization treatment improve the dispersibility and compatibility of the plant-derived functional particles in fibers and ensure more lasting and effective functional performance, and meanwhile, the components of the plant-derived functional particles are all derived from the nature and have the characteristics of reproducibility and degradability, so that the plant-derived functional particles can effectively replace traditional organic synthesis functional modification aids.

Disclosed is a dispersible bauxite particle comprising at least one bauxite domain and at least one nutrient domain, at least one pesticide domain, at least one bio-additive domain, at least one adsorbent domain, or a combination thereof, present in the dispersible bauxite particle, aggregated together as different domains, or comprising bauxite pellets and a water-soluble binder that agglomerates a plurality of bauxite pellets into dispersible bauxite pellets, wherein the bauxite pellets are not chemically modified by NaOH. A method of improving soil with bauxite is disclosed, comprising applying bauxite to the soil wherein the bauxite is mineral bauxite that is not chemically modified with NaOH, the bauxite having a moisture content of less than 10% by weight, the bauxite having a size of less than 0.6 mm, the bauxite improving the efficacy of phosphates present in the soil by at least 5%.

The invention relates to the technical field of material surface engineering, and discloses a plastic surface treatment process to solve the problems that in the prior art, a plastic surface coating is poor in adhesive force and single in function, and a traditional treatment method is not environmentally friendly. The process sequentially comprises the following steps: pre-treating a base material, and obtaining a clean and stress-free base material through ultrasonic cleaning and thermodynamic stress elimination; performing low-temperature plasma surface activation, performing physical bombardment and chemical modification on the plastic surface by utilizing plasma of specific process gas in a vacuum environment, introducing a large number of active functional groups, and remarkably improving the surface energy; and preparing and applying the functional nano coating, namely forming firm covalent bonds by using the coupling agent in a coating solution containing functional nano particles and a coupling agent and the anchor points, so that the chemical coupling of the functional coating and the plastic substrate is realized.

The invention provides an ultralow-swelling artificial cornea imitating natural cornea fiber arrangement and a preparation method, and belongs to the technical field of biomedical materials.The preparation method comprises the steps that I-type collagen is dissolved in a PBS buffer solution, a photofunctionalization modified active reagent is added for chemical modification, stirring is conducted in a dark place, freeze drying is conducted, and photofunctionalization collagen is obtained; dissolving the photo-functionalized collagen, and then preparing a collagen fiber membrane through electrostatic spinning; and performing phase change DLP 3D biological printing on the biological ink and the collagenous fiber membrane to obtain the keratoprosthesis with the collagenous fiber sandwich structure. Multi-layer arrangement is achieved through DLP 3D biological printing, the fiber trend of the natural cornea is simulated, and the mechanical anisotropy is remarkably improved; through a composite phase change DLP 3D printing mode of GelMA / HA-DN and photo-crosslinking collagenous fibers, the composite phase change DLP 3D printing material has good manufacturability, maintains high light transmittance and maintains high mechanical strength.

The invention discloses a method for screening a non-natural nucleic acid aptamer of targeted thrombin based on streptavidin magnetic beads and application, and belongs to the technical field of biology. According to the method, an initial screening library is efficiently constructed through a primer extension technology, and a chemical modification SELEX technical process is simplified; a streptavidin magnetic bead separation technology is introduced, so that the screening specificity and efficiency are improved, the screening period is remarkably shortened, and the cost is reduced; by selecting non-natural nucleic acid modification sites and adopting a strategy of combining reverse screening and forward screening, high specificity and affinity of the aptamer are ensured, and limitation of an existing screening method is overcome; the screened non-natural nucleic acid aptamer shows high affinity and excellent stability, the aptamer with a specific structure and function is successfully obtained by optimizing the proportion of nucleoside triphosphate monomers and extension reaction conditions, and a wide application prospect is provided for the fields of drug development, biosensor preparation and the like. A new path is opened up for research and application of the nucleic acid aptamer.

Provided herein are modified mRNA sequences and compositions comprising the same, as well as using the same in methods for gene editing.

The invention discloses a preparation method of modified carboxymethyl cellulose lithium for a lithium ion battery, and belongs to the technical field of chemical modification of natural polymer materials, decarboxylation and acidification are performed simultaneously, hydrolysis and lithiation are performed simultaneously, and preparation and purification are simple; a branched structure is grafted on lithium carboxymethyl cellulose, additional carboxyl and hydroxyl are introduced after grafting and hydrolysis, the lithium content of the obtained modified lithium carboxymethyl cellulose is higher than that of common lithium carboxymethyl cellulose, and the grafted branched polymer contains a multi-hydrogen-bond structure, so that the adhesive property is enhanced.

The invention discloses a method for preparing micro-nano fibers through needle-free electrostatic spinning equipment assisted by an ion blower gun, and belongs to the technical field of spinning. The method specifically comprises the following steps: S1, dissolving a high-molecular polymer in a proper solvent to prepare a spinning precursor solution; and S2, preparing the micro-nano fiber from the spinning solution on a suitable collection surface by using an ion blower gun assisted needleless electrostatic spinning device. Through the synergistic effect of directional airflow generated by the ion blower gun and a controllable electric field, fiber surface charges are effectively neutralized, the jet instability is inhibited, and the controllability of a fiber flight path is improved. Meanwhile, the ionic wind assists in enhancing interface attachment between the fiber and the collector, uniform deposition is promoted, and the compactness and adhesive force of the fiber membrane are remarkably improved. According to the method, chemical modification does not need to be carried out on a material system, the intrinsic performance of the fiber is kept, universality and expandability are achieved, and a new path is provided for continuous preparation of the high-performance micro-nano fiber.

The invention discloses a controllable degradation antibacterial filament fiber and a preparation method thereof, a calcium alginate filament fiber is prepared by using a wet spinning technology, and the calcium alginate filament fiber is strongly modified by physical and chemical methods respectively. The chemical modification adopts a cross-linking agent for modification, and the physical modification adopts cellulose nanocrystal (CNC) as a reinforcing material. The tensile breaking strength is improved to 43.25 cN / dtex from 16.35 cN / dtex which is not modified, the tensile breaking strength is improved by 2.6 times, and the degradation period is prolonged to 7 days from 2 days. On the basis, berberine is introduced into the fiber, so that the mechanical enhancement effect can be further achieved by means of the electrostatic attraction effect between materials, the antibacterial performance is obtained, and the antibacterial rate can reach 95.28%.

The invention relates to the field of coal mining subsidence control, in particular to a floor rock stratum chemical modification expansion subsidence reduction control method. Comprising the steps of determining the range of a floor failure zone below a coal seam, and selecting a rock stratum with a certain thickness below the floor failure zone as an isolation protection zone; the lower part of the isolation protection belt is a chemical modified expansion belt; selecting a chemical agent for expansion according to mineral components of the chemically modified expansion zone rock stratum; directional drilling is conducted in a working face roadway, a directional drilling horizontal section is constructed in a chemical modified expansion zone, and directional drilling is conducted in the advancing direction of a working face towards the open-off cut direction; the expansion band is chemically modified through directional drilling fracturing; and after the working face is pushed over the horizontal section of the directional drilling hole and before the working face reaches the hole opening of the directional drilling hole, a chemical agent is injected into the chemical modified expansion zone through the directional grouting drilling hole. According to the method, the base plate rock stratum is chemically modified to generate an expansion effect, so that the base plate rock stratum is lifted to support the goaf, the subsidence of the overlying rock stratum is reduced, and the surface subsidence is controlled.

The invention relates to a training method of an RNA sequence modification prediction model, a prediction method and a related device. The method comprises the following steps: acquiring modification site sequencing data of an RNA sequence; on the basis of sites with target chemical modification and sites without target chemical modification in the modification site sequencing data, a plurality of positive sample sequences with different lengths and a plurality of negative sample sequences with different basic groups added at the central position are obtained respectively, so that a multi-level classification database is constructed; inputting each sample sequence in the multi-level classification database into a to-be-trained modification prediction model to obtain a prediction result of a modification site of each sample sequence; and on the basis of the prediction result and the actual condition of each sample sequence, updating model parameters of the to-be-trained modification prediction model until the trained modification prediction model is obtained. Compared with the prior art, the method can improve the training efficiency and precision of the model.

The invention discloses a modification method and application of recycled concrete aggregate. The modification method comprises the following steps: pretreatment, physical modification, chemical modification and surface enhancement treatment. The waste concrete is efficiently recycled, the pollution of construction waste to the environment is reduced, the exploitation amount of natural aggregate is reduced, and natural resources are protected; meanwhile, a physical, chemical and surface enhancement treatment synergistic modification mode is adopted, and modification steps are mutually matched and promoted; physical modification creates good surface conditions for chemical modification, chemical modification further optimizes the surface components and structure of the aggregate, surface enhancement treatment finally improves the surface performance of the aggregate, various problems existing in the recycled aggregate are effectively solved, and the comprehensive performance of the recycled aggregate is comprehensively improved; the application range of the building material in building engineering is expanded, the cost of the building material is reduced, and the building material has remarkable economic benefits and environmental benefits.