44results about How to "Act as a physical barrier" patented technology

The invention belongs to the technical field of lithium-sulfur batteries, and relates to a membrane and for a lithium-sulfur battery. The membrane comprises a membrane body and a covering layer, the covering layer comprises graphene and heterojunction nano materials, the heterojunction nano materials are a symbiotic high adsorption phase-high conductivity phase, the mass ratio of the graphene to the heterojunction nano materials is (3-15):1, and the mass ratio of the high adsorption phase to the high conductivity phase is (1-10): (10-1). Relative to the prior art, according to the membrane, the covering layer is arranged on the membrane, electrochemistry and dynamics performances of the lithium-sulfur battery can be greatly improved, heterojunction nano materials specifically comprise the high adsorption phase and the high conductivity phase, the high adsorption phase has high adsorption action on polysulfide, the high conductivity phase has high conductivity action on the polysulfide, the polysulfide adsorbed by the high adsorption phase can be diffused on the surface of the high conductivity phase, so that transformation of the polysulfide is finished, adsorption and transformation at an interface between the high adsorption phase and the high conductivity phase can be finished, and the 'shuttling effect' of the polysulfide is restrained.

The invention relates to a preparation method of a microencapsulated gradient halogen-free flame retardant system. The preparation method comprises the steps of: mixing a phosphorus-series flame retardant with an inorganic flame retardant according to a certain ratio to obtain a microencapsulated halogen-free flame retardant, then carrying out surface modification on a charring agent, and then mixing the microencapsulated halogen-free flame retardant, a phosphorus-containing organic flame retardant and surface-modified charring agent according to a certain ratio to obtain the microencapsulated gradient halogen-free flame retardant system. By using the system, distributed gradient flame retarding is realized, the flame retardancy of a polymer material is greatly improved, the defect that compatibility between the flame retardant and the polymer is poor is solved, the migration of the halogen-free flame retardant from the polymer matrix under high-temperature and moisture conditions is significantly reduced, and the long-term storage of a flame-retardant polymer material is facilitated. The method has the characteristics of simple process, convenience for operation, environmental friendliness, and lower cost. The obtained flame retardant system has good flame retarding effect and wide application field.

The invention relates to the field of gynecological medical apparatus and instruments, in particularly to an implant for uteruses. The implant for the uteruses comprises a membrane (1). The implant for the uteruses has the advantages that problems of irritation influence on uteruses due to existing implants implanted in uterine cavities for a long time, poor uterine mucous membrane repair effects of conventional medicine, influence on the whole bodies of patients due to hormone medicine for oral administration and the like can be solved by the aid of the medicine to a great extent, and effects and individual degrees can be greatly improved during phased utilization.

The invention relates to a carbon nitride composite material and a preparation method and an application thereof. The carbon nitride composite material comprises a substrate and a composite coating layer for covering the surface of the substrate; the composite coating layer comprises carbon nitride, a conductive agent and a binder; the conductive agent is selected from at least one kind of active carbon, acetylene black, Ketjen black, graphite, graphene and carbon nanotubes. The carbon nitride composite material can be applied to a diaphragm of a lithium-sulfur battery; when a polysulfide exists, the conductive agent can transfer electrons generated in the charge-discharge process, so that an effect of a second current collector as well as an effect of physical isolation can be played; in addition, carbon nitride has relatively high physical isolation effect and large specific surface area; and due to existence of the nitrogen element, shuttling of the polysulfide can be suppressed by the dual chemical and physical absorption effects effectively, thereby enabling the lithium-sulfur battery to be relatively high in discharge specific capacity and cycling stability.

The invention discloses a graphene modified waterborne epoxy resin coating material as well as a preparation method and application thereof. The graphene modified waterborne epoxy resin coating material is prepared from a component A' of which the solid content is 53 percent and a component B of which the solid content is 40 percent. The graphene modified waterborne epoxy resin coating material ofwhich the solid content is 33 percent is obtained by mixing the component A' with the component B according to a mass ratio of (1.5 to 4):1, adding deionized water, and uniformly mixing, wherein thecomponent A' is graphene modified waterborne epoxy resin emulsion and is obtained by adding 0.1 to 1 mass percent of graphene derivative in waterborne epoxy resin emulsion. The component A' is stablystored for a long term and has no precipitate after one-year storage. The obtained graphene modified waterborne epoxy resin coating material after the component A is applied is higher in corrosion resistance, conductivity and thermal stability, and the preparation method is safe and environmentally friendly, does not use heavy metal ions and volatile organic solvents and accords with the idea of environment-friendly protection.

The invention discloses a long glass fiber reinforced flame-retardant ABS composite material and a preparation method thereof. The composite material comprises polycarbonate, ABS, a flame retardant material, modified fibers, modified graphene oxide and other components, and the surface of the modified graphene oxide is treated with a silane coupling agent, so that the compatibility of the grapheneoxide and matrix components (polycarbonate and ABS) is improved, the graphene oxide and the matrix components can be uniformly dispersed in a system, the modified fiber is mainly prepared from blackphosphorene, dopamine, absolute ethyl alcohol and pretreated fiber, the pretreated fibers are glass fibers with carbon nanowires growing on the surfaces, and the glass fibers are continuous glass fibers. By utilizing the synergistic effect of the aluminum hydroxide, the magnesium hydroxide, the polysiloxane, the modified graphene oxide and the black phosphorene, the ABS composite material has excellent flame retardance, and is low in smoke, low in toxicity and higher in practicability during combustion.

The invention discloses a high-voltage and high-rate type lithium cobalt oxide cathode material and a preparation method thereof. The preparation method comprises steps as follows: cobalt oxide and lithium carbonate are taken as precursors, magnesium carbonate is added, and lithium cobalt oxide can be obtained after primary sintering and breaking; an aluminum alkoxide and titanate mixed alcoholic solution is added, secondary sintering is performed after mixing, and lithium cobalt oxide can be obtained. When discharge voltage is up to 4.5 V and the rate is 0.2C (1C=177.5 mAh/g), specific capacity of lithium cobalt oxide prepared with the method is higher than 190 mAh/g, rate performance of 1C/0.2C is higher than 98%, and 3.6V voltage platform occupancy is higher than 99%; the material has the characteristics of stable structure and smaller specific discharge capacity attenuation in a high-voltage and high-rate charging and discharging process; according to the method, a voltage window, capacity performance and rate performance of the lithium cobalt oxide cathode material are successfully improved, further, the technology is simple, the implementation is convenient, the cost is low, and the prepared high-voltage and high-rate type lithium cobalt oxide cathode material has excellent electrochemical performance.

The invention discloses an aluminum oxide/titanium oxide heterojunction nano fiber carrier in an anti-sintering precious metal catalyst system as well as a preparation method and application of the carrier. The preparation method comprises the following steps: dispersing PVP into ethyl alcohol, stirring and dissolving to obtain a PVP ethyl alcohol solution; taking glacial acetic acid to be added into the solution, and adding titanium isopropoxide; dispersing aluminum acetylacetonate into an organic solvent, mixing and stirring the two solutions to obtain a precursor solution, adopting an electrostatic spinning method, indrawing the precursor solution in an injector, inserting the injector into a trace injection pump, connecting with an electrode, adjusting the flow speed and the voltage of an electrostatic field, wherein the distance from a syringe needle to a receiver is 5-15cm, and controlling the indoor humidity to be 30-50%, thereby obtaining nano fibers; sintering the nano fibers obtained by the electrostatic spinning method in a muffle furnace, thereby obtaining the aluminum oxide/titanium oxide heterojunction nano fiber carrier. The catalyst carrier disclosed by the invention is short in preparation cycle, simple in process, low in energy consumption, high in productivity, and good in reproducibility.

The invention relates to a stomach tube with a device for preventing the backflow of gastric content, which is divided into a head part, a middle part and a tail part. The stomach tube is characterized in that a main channel for infusing nutrient solutions, water and medicaments is penetrated through the head part, middle part and tail part in the stomach tube; the head part is provided with two parallel cavities; the upper end opening of the main channel is communicated with the head part of the stomach tube and is open at a main cavity of the two parallel cavities; a subsidiary cavity for infusing gas is further arranged in the two parallel cavities at the head part of the stomach tube; the subsidiary cavity is provided with a charging connector having a locking device; the subsidiary cavity is communicated with an umbrella-shaped backflow-preventing device around the outer wall at the middle lower part of the stomach tube through a gas bag channel positioned in the wall of the stomach tube; and the tail part of the stomach tube is provided with the lower end opening of the main channel. The invention can effectively solve the serious clinical problem such as suffocation, inhalation pneumonia and the like caused by mistakenly inhaling gastric content backflow into the trachea.

The invention discloses a graphene slurry for a cationic waterborne polyurethane coating, and a preparation method and application thereof. The graphene slurry for the cationic waterborne polyurethane coating is an aqueous dispersion of modified graphene prepared by modifying graphene oxide with carbodiimide to obtain the modified graphene and then dispersing the modified graphene in water, wherein in the aqueous dispersion of the modified graphene, a ratio of the modified graphene to water is 2-20 mg: 1 ml in terms of the dry weight of the modified graphene. The graphene slurry can be cooperated with cationic waterborne polyurethane resin, so the advantage of long-term stable dispersion is obtained, and the graphene slurry is friendly to environment, long in storage time and free of precipitation, flocculation and gelation after storage at room temperature for one year or more. A coating prepared from the graphene slurry has elastic modulus of 2.2-2.31 GPa and neutral salt spray time of 72 to 120 h.

The invention relates to the technical field of phase change materials, in particular to a metal ion/zirconium phosphate aerogel, a preparation method thereof and a composite phase change energy storage material. According to the metal ion/zirconium phosphate aerogel, a sacrificial metal ion ligand enhanced coordination bond is formed between zirconium phosphate nanosheets in the metal ion/zirconium phosphate aerogel, and the interaction between the zirconium phosphate nanosheets is increased, so that the mechanical strength of a composite phase change material is improved; a large number of acid points and Lewis acid points exist between zirconium phosphate nanosheet layers, polymer crosslinking and carbonization can be catalyzed during high-temperature combustion, in addition, zirconiumphosphate nanosheets can also play a physical barrier role, and the zirconium phosphate nanosheets and the polymer crosslinking and carbonization can jointly prevent diffusion of oxygen and heat, so that the composite phase change material has excellent flame retardant property. Zirconium phosphate aerogel in the metal ion/zirconium phosphate aerogel can load more phase change materials, and the energy storage density is improved.

The invention relates to a composite polymer gel electrolyte as well as a preparation method and application thereof, which solves the technical problems of single performance and poor mechanical property of the existing material. The composite polymer gel electrolyte consists of an ammonium polyphosphate modified polyacrylonitrile electrolyte layer and a carbon nano tube/polyacrylic acid layer. The invention further provides a preparation method and application of the composite polymer gel electrolyte. The preparation method can be applied to the field of battery electrolyte preparation.

The invention relates to an implantable flexible electronic device and a preparation method thereof, and the preparation method comprises the steps: providing a body which comprises a flexible substrate and a circuit assembly disposed on the flexible substrate; manufacturing a hydrophobic shell layer wrapping the body on the body; and manufacturing a hydrophilic shell layer wrapping the hydrophobic shell layer on the hydrophobic shell layer to obtain the implantable flexible electronic device. The Young modulus of the implantable flexible electronic device is closer to the Young modulus of human tissues, and the implantable flexible electronic device has excellent biocompatibility and waterproof effect and is more excellent in use effect.

The invention discloses graphene slurry for anionic aqueous polyurethane coatings, a preparation method of the graphene slurry and an application. The graphene slurry for the aqueous polyurethane coatings is modified graphene aqueous dispersion, oxidized graphene is modified by carbodiimide to obtain modified graphene, and the modified graphene is dispersed into water to obtain the modified graphene aqueous dispersion. In the modified graphene aqueous dispersion, according to the dry weight of the modified graphene, the ratio of the modified graphene to water is 2-20mg: 1ml. The graphene slurry can be matched with anionic aqueous polyurethane resin to achieve the advantage of long-term dispersion stability, is environmentally friendly and long in preservation time, and is capable of being preserved for at least one year at room temperature without deposition, flocculation or gelling. After use, the elastic modulus of the finally obtained coatings can reach 2.23-2.34GPa, and neutral salt spray time can reach 60-120 hours.

The invention belongs to the field of methanation catalysis, and relates to an organic silicon waste contact body borne nickel-based methanation catalyst and a preparation method therefor. The catalyst comprises a carrier, an active component, a modifier and an auxiliary agent, wherein the carrier is an organic silicon waste contact body, the modifier is a porous inorganic oxide, the active component is Ni, and the auxiliary agent is a transition metal oxide. By using the porous inorganic oxide modifier in the invention, on one hand, the interacting force between the active component and the carrier is enhanced, and the dispersibility of the active component is improved; on the other hand, the inorganic oxide dispersed in the active component further serves as a physical barrier, and suppresses agglomeration and sintering of Ni particles. The catalyst obtained in the invention is high in catalytic activity, high in anti-carbon deposition and anti-sintering performance and low in cost, and particularly suitable for methanation reaction systems of high-concentration CO.

The invention discloses a formula of a high-flame-retardant material for a window screen. The formula comprises polypropylene, polyethylene, polyethylene terephthalate, a flame retardant, a surfactant, an antioxidant, an anti-dropping agent and a lubricant. The high-flame-retardant material for the window screen, disclosed by the invention, has the beneficial effects that aluminum powder is used as the flame retardant, so that the flame retardant effect is good, the heating rate of a material is slowed down, the combustion is hindered, and the aluminum powder covering the surface of the material plays the role of a physical barrier, and can insulate heat and oxygen and inhibit the flow of a flammable gas to a matrix to achieve the effect of flame retardancy; the high-flame-retardant material has excellent weather resistance, aging resistance, heat resistance and long service life, and does not decompose to produce toxic substances; the high-flame-retardant material has no smoke or toxic substances in a combustion process, and has good strength and impact resistance; furthermore, the material has good bonding performance and does not need to use additional binders when being woven into a yarn mesh, thereby being safe and environmentally friendly.