243 results about "Polyvinylidene difluoride" patented technology

When a conventional porous membrane is used for a contaminative liquid to be filtered, the surface of the membrane is blocked due to turbid matter separated by filtration and, as a result, membrane clogging occurs, so that the permeation performance tends to deteriorate. Provided is a porous membrane that has high water permeability and excellent contamination resistance, and is capable of maintaining high filtrate permeability for a contaminative liquid to be filtered. The porous membrane contains a polyvinylidene fluoride resin, in which, given that one surface is a surface A and another surface is a surface B, a ratio (ratio of Hα / Hβ) between an α-type crystal (Hα) and a β-type crystal (Hβ) in a crystalline portion of the polyvinylidene fluoride resin measured by an attenuated total reflection (ATR) method at the surface A is 0 or more and 0.5 or less, a pure water permeability is 0.25 to 1.2 m3 / m2 / h / 50 kPa, and an average value of a surface pore diameter of a surface pore of the surface A of the porous membrane is 5.0 nm or more and 12.0 nm or less.

The present application belongs to the field of piezoelectric gel materials, and particularly relates to a polyvinylidene fluoride polymer flexible piezoelectric hydrogel with island structure and a preparation method and application thereof. The flexible piezoelectric hydrogel is a three-dimensional continuous network formed by cross-linking of a hydrophilic polymer as a continuous phase, and polymer microspheres with uniform particle size formed by a hydrophobic polyvinylidene fluoride polymer as a uniformly dispersed dispersed phase. The island structure significantly improves the mechanical properties and piezoelectric properties of the gel. The piezoelectric gel material can be used for human sensing, detecting motion signals and pulse signals, and has high industrial production potential and biomedical application prospect.

The aim is to improve stain resistance while maintaining water permeability, that is, to suppress clogging in the membrane. [Solution] The hollow fiber membrane of the present invention comprises a spherical structure containing a polyvinylidene fluoride resin, wherein a hydrophilic polymer is present on the surface and inside the spherical structure, and the hydrophilic polymer present inside the spherical structure accounts for 70% by mass or less of the total hydrophilic polymer contained in the entire hollow fiber membrane, with the amount of the hydrophilic polymer being 1.0 part by mass or more per 100 parts by mass of the polyvinylidene fluoride resin.

This invention belongs to the field of hollow fiber membrane preparation technology, and discloses a braided tube-reinforced polyvinylidene fluoride hollow fiber hydrophobic membrane, its preparation method, and its application. The polyvinylidene fluoride hollow fiber hydrophobic membrane includes a braided tube and a hydrophobic membrane layer formed on the surface of the braided tube. The outer diameter of the braided tube-reinforced polyvinylidene fluoride hollow fiber hydrophobic membrane is 0.3-3 mm, the tensile breaking strength is greater than 100 N, and the pure water permeability is 200-7500 L / (m²). 2 •h)@0.1MPa 20℃. The preparation method includes: preparing a casting solution by combining polyvinylidene fluoride resin, organic solvent, composite pore-forming agent, and optionally polytetrafluoroethylene microparticles; extruding the casting solution onto the outer surface of a braided tube using a hollow fiber membrane spinning machine, and forming a membrane through phase separation in a coagulation bath. This invention significantly improves the mechanical strength of the membrane through braided tube reinforcement and achieves high flux and high hydrophobicity using a water-inorganic-organic composite pore-forming agent, making it suitable for high-performance separation processes such as membrane distillation, membrane contactors, and gas separation.

The application provides an oil-based multi-walled carbon nanotube slurry as well as a preparation method and application thereof. The oil-based multi-walled carbon nanotube slurry comprises 1-23% by mass fraction of multi-walled carbon nanotubes, 0.1-5% by mass fraction of sodium 4-styrenesulfonate, 0.5-35% by mass fraction of polyvinylidene fluoride and 57-98.4% by mass fraction of N-methylpyrrolidine. The multi-walled carbon nanotubes in the oil-based slurry are uniformly dispersed, and the multi-walled carbon nanotubes exist in a monodisperse form and are not prone to agglomeration. The oil-based multi-walled carbon nanotube slurry has stable physical and chemical properties, can be stored for a long time and is not prone to stratification. The oil-based slurry can be directly used in the homogenization process of the oil-based slurry, the multi-walled carbon nanotubes in the pole piece prepared after coating are uniformly distributed, the preparation process of the oil-based slurry is simple, the system temperature in the preparation process is constant and controllable, and the oil-based slurry can be prepared and applied on a large scale.

The application discloses a high-thermal-conductivity Ga / CF composite material and a preparation method thereof, and relates to the technical field of composite materials. The composite material is prepared from 1-3 mu m gallium pellets as a thermal conductive phase, 8K carbon fiber cloth as a thermal conductive support framework, and polyvinylidene fluoride as a binder through a binder preparation process, ultrasonic treatment, centrifugal purification of the gallium pellets, ball milling, coating and compaction, and drying and curing. The gallium pellets are uniformly dispersed through the specific process, the interface bonding performance of the thermal conductive phase, the support framework and the binder is optimized, and the technical problems of gallium agglomeration, discontinuous thermal conductive paths and poor interface bonding are solved. The obtained composite material has excellent thermal conductive performance and structural stability, the whole preparation process is carried out at a low reaction temperature, is environment-friendly, is suitable for the fields of electronic device heat dissipation and flexible heat management modules, and has a wide application prospect.

The invention relates to (i) a spinning fluid for flash spinning polyvinylidene fluoride (PVDF) or polyvinylidene fluoride blends from a spin dope comprising dichloromethane and a cyclic hydrofluorocarbon, and (ii) a method for producing a plexifibril of PVDF or PVDF blends using the spinning fluid.

The present application relates to a kind of porous gel electrolyte membrane based on polyvinylidene fluoride and its preparation method, belong to polymer gel electrolyte field.The porous gel electrolyte membrane includes gel electrolyte matrix, inorganic ceramic nano filler, lithium salt electrolyte and lithium salt auxiliary agent.Using phase inversion solidification method, the uniform porous structure is obtained, the adsorption and storage capacity of porous gel electrolyte membrane to electrolyte are improved;Using inorganic ceramic nano filler with high ionic conductance, the ionic conductance and mechanical strength of porous gel electrolyte membrane are enhanced;Using lithium salt added during preparation, the dehydrofluorination reaction of PVdF is inhibited, the stability of slurry is ensured, and by inducing the transition of PVdF matrix from alpha phase to beta phase, the uniform deposition of Li ion is promoted, so as to improve the cycle stability of battery.The preparation method of the present application is simple, easy to control, green and environmentally friendly, can significantly improve the ion transport kinetics and electrochemical stability of lithium ion battery.

The application discloses a high-beta-crystal-phase polyvinylidene fluoride fiber piezoelectric film and a preparation method thereof, wherein the preparation method comprises the following steps: step one: polyvinylidene fluoride resin with a weight average molecular weight of 500,000-800,000, a long branched chain content of 1.2‰-5‰, and a 7% mass fraction NMP solution rotary viscosity of 5000-8000 mpa.s at 25 DEG C is prepared by emulsion polymerization of polyvinylidene fluoride monomer and difluoro-monochloroethane; and step two: the polyvinylidene fluoride resin obtained in step one is made into an electrostatic spinning precursor solution, and the electrostatic spinning precursor solution is spun and film-formed by an electrostatic spinning method. The polyvinylidene fluoride nanofiber film with finer and higher beta-crystal-phase content can be prepared by adjusting the content of the long branched chain and the viscosity of the electrostatic spinning solution.

The application belongs to the technical field of composite micro / nano fiber materials, and particularly relates to a polyimide and polymer composite micro / nano fiber nonwoven fabric, a preparation method and application thereof. The nonwoven fabric is a three-dimensional porous network composed of composite micro / nano fibers with a skin-core structure; the skin layer material of the composite micro / nano fiber is polyimide, and the core layer material is a polymer; the polymer is at least one of polyacrylonitrile, polyvinylidene fluoride and polyarylene ether. The preparation method is to prepare polyimide spinning solution and polymer spinning solution respectively, then perform coaxial electrospinning, and then perform post-processing. The polyimide and polymer composite micro / nano fiber nonwoven fabric has excellent chemical corrosion resistance, excellent mechanical properties, excellent thermal stability, low cost, uniform material compounding, high porosity and high efficient cyclic adsorption performance, can efficiently remove heavy metal ions and organic dyes in water, and has a wide application prospect in the field of water treatment.

A positive electrode mixture layer of this positive electrode for secondary batteries contains a positive electrode active material, a binder, a conductive material, and an ion-binding compound. The positive electrode active material contains lithium-containing transition metal oxide particles and a boron compound that is present on the surfaces of the lithium-containing transition metal oxide particles. The binder contains a polyvinylidene fluoride. The difference in electronegativity between the cation of the ion-binding compound and oxygen is 1.7 or more. The content ratio of the polyvinylidene fluoride is 1 mass% or less. When the positive electrode mixture layer is subjected to elemental analysis by EPMA, the ratio of the number of aggregates of a specific element indicating the ion-binding compound detected overlapping elemental F detected in a region from a current collector to 50% of the total thickness of the positive electrode mixture layer to the total number of aggregates of the specific element indicating the ion-binding compound detected in the region is 70% or more.

The invention discloses a lithium manganate positive electrode material, a preparation method and an applied lead-lithium battery, relates to the technical field of lithium manganate positive electrode materials, and solves the problems that the existing lithium manganate positive electrode material is poor in structure and interface stability and poor in rate and cycle performance. The positive electrode material is composed of a lithium manganate matrix and a double-layer composite coating, the matrix is prepared by taking lithium carbonate and manganous-manganic oxide as raw materials and doping magnesium hydroxide, aluminum hydroxide and titanium dioxide multi-plasma phase; the lithium manganate positive electrode material is prepared by uniformly compounding a lithium manganate matrix modified by a spinel inner layer, vinyl functionalized MOF and a polyvinylidene fluoride-hexafluoropropylene copolymer on the surface of an aluminum foil receiver through an electrospinning-electrospray synergistic process. The material is applied to the lead-lithium battery, shows excellent electrochemical performance and has good practical application value.

The application discloses an array material and a method for detecting VOCs components in gas, and the array material is obtained through the following steps: step 1: each dye is respectively dissolved in an ethanol solution to obtain a dye reagent; the concentration of the ethanol solution is 50%; step 2: polyvinylidene fluoride film is selected as a substrate, the dye reagent obtained in step 1 is separately and individually added on the polyvinylidene fluoride film to form a plurality of dye detection points and form a detection array; then a sealing film is covered above and below the polyvinylidene fluoride film, the polyvinylidene fluoride film is sealed, and an air inlet hole and an air outlet hole are respectively formed above and below the sealing film and correspond to the positions of each dye detection point; nitrogen is slowly blown to the polyvinylidene fluoride film to obtain the array material. According to the method, the array material constructed in the application can clearly distinguish a plurality of volatile organic compounds through visual results or pattern recognition, and the recognition accuracy is high.

This application provides a high-voltage electrochemical composite hydrogel for wound skin repair and its preparation method. The high-voltage electrochemical composite hydrogel is prepared by using hydroxyethyl cellulose and acrylamide monomers as raw materials to form an interpenetrating network structure. Polyvinylidene fluoride (PVDF) and ZnO nanowires are used as piezoelectric materials, and are formed by interweaving PVDF and ZnO nanowires within the hydrogel. This high-voltage electrochemical composite hydrogel significantly improves the crystallization orientation and polarization efficiency of PVDF through mechanical stretching and polarization, resulting in an order-of-magnitude improvement in the piezoelectric properties of the composite hydrogel. Simultaneously, it retains the excellent flexibility and biocompatibility of the hydrogel, showing broad application prospects in flexible sensors, self-powered devices, and human-computer interfaces.

This application relates to a copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from fluorinated monomer M1, having a melting temperature Tm defined by the following relationship: (154.45 - 1.9472*x) - 3 < Tm (°C) < (154.45 - 1.9472*x) + 3 (where x is the weight content of the fluorinated monomer M1 expressed as a percentage based on the total weight of the copolymer, and the melting temperature is measured by DSC according to the ASTM E794-06 standard test method). This application also relates to the use of the composition in various technical fields.

The disclosure provides a composite semi-solid electrolyte membrane with carbon-carbon double bond structure and a preparation method, the composite semi-solid electrolyte membrane comprises: a modified polymer matrix, which is obtained by treating polyvinylidene fluoride or its copolymer with a metal hydroxide solution, the treatment forms a carbon-carbon double bond structure on the polymer backbone, and in-situ generates and uniformly disperses inorganic fluoride particles in the modified polymer matrix; reinforcing fibers, which are dispersed in the modified polymer matrix and interweave to form a three-dimensional network skeleton; and additives, which are dispersed in the modified polymer matrix and used to provide lithium ion carriers for the lithium ion battery. The disclosure realizes the synergistic improvement of the ion conductivity, mechanical strength and thermal stability of the composite semi-solid electrolyte membrane by generating carbon-carbon double bond structure and inorganic fluoride through chemical modification and combining with the fiber reinforcement technology, and exhibits good application prospect in the semi-solid lithium ion battery.

A carbon dioxide mineralization process is disclosed, which includes introducing ammonium hydroxide solution and a calcium chloride solution into a reaction vessel to form a mixed solution, introducing carbon dioxide gas into the reaction vessel, and forming a calcium carbonate precipitate. Implementations of the carbon dioxide mineralization process can include where the mixed solution further may include tannic acid. A concentration of tannic acid can be from about 0 mg / mL to about 2 mg / mL. A flow rate of the introduction of carbon dioxide gas can be from about 0 L / min to about 1.0 L / min. The carbon dioxide mineralization process may include providing ultrasonic energy at a frequency of from about 20 khz to about 130 khz to the mixed solution. The carbon dioxide mineralization process may include filtering the calcium carbonate precipitate through a polyvinylidene fluoride membrane. The calcium carbonate precipitate may include a metastable vaterite phase.

This invention discloses an outdoor flooring and its preparation method, belonging to the field of wood-plastic composite flooring technology. The flooring comprises a substrate board, a uniform color carrier film layer, a digitally printed pattern layer, and a transparent layer. The transparent layer is integrally formed from a polyvinylidene fluoride resin layer with a thickness of 0.1~0.45mm and a resin layer containing methyl methacrylate segments with a thickness of 0.06mm or more. This invention innovatively adopts a double-layer structure of "thick PVDF + thin PMMA," breaking through by using PVDF as the main load-bearing surface layer, which combines wear resistance, weather resistance, and high water resistance. This fundamentally blocks moisture penetration and solves the failure problems of traditional PMMA-coated boards, such as blistering, delamination, and cracking, which are prone to occur in high-temperature and high-humidity environments. This structure achieves a balance of high wear resistance, high weather resistance, high water resistance, and strong interfacial bonding while controlling costs, making it particularly suitable for harsh outdoor environments and significantly improving the product's service life.

A multilayer Janus membrane with directional wettability includes a polyvinylidene fluoride (PVDF) layer, a polyetherimide (PEI) layer and an intermediate layer of copper oxide nanoparticles and vinylidene fluoride and hexafluoropropylene copolymer (PVDF-HFP) or polyacrylonitrile (PAN). The intermediate layer is in contact between the PVDF layer and the PEI layer, and the PEI fibers interlock between the granular particles of the intermediate layer.

This invention discloses a PVDF-modified ultrafiltration membrane based on a tannic acid crosslinking network, its preparation method, and its applications. The membrane is prepared by a phase inversion membrane fabrication method using polyethyleneimine, tannic acid, polyvinylidene fluoride (PVDF), and N,N-dimethylacetamide (NDM). The pyrogallol structure abundant in the tannic acid molecule can coordinate with metal ions and also form a robust covalent crosslinking network with the amine-rich polyethyleneimine through Michael addition and Schiff base reactions. This network firmly anchors TA to the membrane surface and pores, solving the problem of TA loss in traditional modifications. The introduction of TA imparts lasting hydrophilicity to the membrane, significantly improving pure water flux and separation efficiency. Simultaneously, the hydrophilic and positively charged surface synergistically constructed by TA and PEI effectively inhibits the adsorption and deposition of pollutants, endowing the membrane with excellent antifouling performance and operational stability. This PVDF membrane, prepared through a green and simple co-crosslinking strategy, shows broad application prospects in complex water treatment and bioseparation.

The application discloses a high-transmission wide-temperature-range sodium ion battery anode based on a two-phase layered oxide and a preparation method and application thereof, and belongs to the technical field of sodium ion batteries. The sodium ion battery anode comprises an anode active material, a conductive agent and a binder, wherein the anode active material comprises a layered oxide component and a complex component; the layered oxide component comprises O3-phase NaNi 0.2 Fe 0.2 Co 0.2 Mn 0.2 Ti 0.2 O2 and P2-phase Na 0.67 Ni 0.33 Mn 0.37 Ti 0.3 O2, the complex component comprises Na2MnPO4F, Na2FePO4F and Na2FeSiO4, the conductive agent is a mixture of super conductive carbon black (SP) and carbon nanotubes (CNT), and the binder is polyvinylidene fluoride (PVDF). The O3 / P2 two-phase layered oxide provides high capacity and structural stability, the polyanion compound material guarantees ion transmission and thermal stability, and the conductive agent optimizes electron transmission. The prepared sodium ion battery has the effects of breaking through the low-temperature performance limitation, significantly improving the sodium ion transmission efficiency, cycle stability and excellent safety and stability.

The present application relates to a kind of hyperbranched polyvinyl fluoride resin prepared by suspension polymerization with chain transfer agent and its preparation and application, the preparation method of the resin includes: under the condition of using at least one initiator, at least one chain transfer agent, at least one dispersing agent, make polyvinyl fluoride occur polymerization reaction;The chain transfer agent is at least one chain transfer agent of multiple chain transfer sites (≥2) or the combination of liquid phase transfer agent and gas phase transfer agent forms multiple chain transfer sites.Compared with prior art, the polyvinyl fluoride resin of the present application has hyperbranched configuration, and high mechanical strength and good processing performance are considered, the resin is especially suitable for being used as the inner lining material of marine non-adhesive flexible riser, submarine cable packaging layer and other fields, its excellent chemical corrosion resistance, gas permeation resistance and heat aging performance can effectively block the erosion of external corrosive medium to internal tensile armor layer.

This invention discloses an oil-based conductive slurry, its preparation method, and its application. The oil-based conductive slurry comprises an oil-based solvent, a conductive material, and an oil-based binder. The oil-based binder is polyvinylidene fluoride (PVDF), and the conductive material is one or a mixture of several of acetylene black, Ketjen black, conductive carbon black, conductive graphite, graphene, and carbon nanotubes. The oil-based conductive slurry is coated on both sides of an aluminum foil and dried to obtain a coating on the aluminum foil, resulting in a carbon-coated current collector. The carbon-coated current collector is used to prepare a positive electrode sheet. The uniform distribution of the conductive material in the oil-based solvent forms a continuous conductive network, which effectively reduces the surface resistance of the aluminum foil, promotes rapid electron conduction, and improves the charge / discharge efficiency and energy density of the battery. The formation of a conductive carbon layer between the aluminum foil and the positive electrode coating reduces the interfacial resistance and improves conductivity.

The invention relates to the technical field of fluororubber processing, in particular to a fluororubber sealing element resistant to electrolyte corrosion and a preparation method of the fluororubber sealing element. The fluororubber is prepared from the following raw materials in parts by weight: 100 parts of fluororubber, 10-15 parts of polytetrafluoroethylene micro powder, 4-8 parts of an acid acceptor, 5-7 parts of magnesium-aluminum hydrotalcite, 3-5 parts of polyhedral oligomeric silsesquioxane, 35-40 parts of inorganic filler, 30-35 parts of carbon black, 8-10 parts of an active agent, 2-5 parts of a peroxide vulcanizing agent and 2-5 parts of a cross-linking agent. The fluororubber is composed of low-fluorine-content binary fluororubber and a polyvinylidene fluoride-hexafluoropropylene copolymer, through the synergistic effect of all the components, the volume swelling rate of the sealing element is controlled to be 8% or below under the condition that the sealing element is soaked in an electrolyte at the temperature of 85 DEG C, and the compression set is reduced to be within 15%; and after accelerated aging for 1000 hours, excellent elastic recovery capability and interface sealing pressure are still maintained. The sealing element has the wide temperature range adaptability of-20 DEG C to 200 DEG C and good mechanical strength, and the problem of size instability caused by swelling and softening of traditional fluororubber is effectively solved.

The present application relates to the technical field of solid-state battery materials, and particularly relates to a preparation method of a nontronite-coated LLZTO-based composite solid-state electrolyte film and application thereof. The preparation method comprises the following steps: 1) mixing nontronite and LLZTO in the presence of a dispersion medium, ball milling, drying, and obtaining a composite filler coated with nontronite on the surface; 2) mixing the composite filler in step 1) and polyvinylidene fluoride-hexafluoropropylene and lithium bis-trifluoromethanesulfonimide in the presence of a solvent, and obtaining an electrolyte slurry; 3) solution casting the electrolyte slurry in step 2), and vacuum drying to obtain a composite solid-state electrolyte film. The P-CPE electrolyte film of the present application is used in a solid-state lithium battery, can construct a continuous and stable ion transmission channel, homogenize lithium ion flux, inhibit dendrite growth, and exhibit excellent cycle stability and rate performance.

The present invention relates to a method for producing polyvinylidene fluoride with polymerization of vinylidene fluoride, in particularly using a polymerization reactor that comprises a membrane.

The application provides a clindamycin phosphate external solution and a preparation method thereof. The clindamycin phosphate external solution has good stability and simple preparation process, and can be mass-produced by adding sodium hydroxide and triethanolamine in the solution preparation process and using polyvinylidene fluoride (PVDF) as a filter membrane material.