3249 results about "Polyvinylidene difluoride" patented technology

The invention belongs to the technical field of aqueous zinc ion batteries, and discloses an aqueous zinc ion battery negative electrode coating material and a preparation method and application thereof. Coumarin hydrazide reacts with benzyl isothiocyanate to generate a multi-nitrogen-oxygen-sulfur heteroatom ligand capable of coordinating with zinc ions, and the required aqueous zinc ion battery negative electrode coating material LXB-Zn is further prepared by doping with polyvinylidene fluoride. The synthesized aqueous zinc ion battery negative electrode coating material contains imino groups and heteroatoms S, O and N, can inhibit a hydrogen evolution reaction and provides more active sites, so that dendrites and side reactions are inhibited, and the cycling stability of an aqueous zinc ion battery is effectively improved. In order to solve the problem that an organic coating of a water-based zinc ion battery negative electrode is difficult to prepare, the organic coating of the water-based zinc ion battery negative electrode is prepared by adopting a simple method of adding an adhesive.

The invention discloses a lithium battery diaphragm coating based on a nano material and application thereof, and relates to the technical field of lithium battery diaphragms. The coating comprises the following raw materials in parts by weight: 15-25 parts of polystyrene maleic anhydride copolymer modified polyvinylidene fluoride, 10-20 parts of polystyrene, 2-4 parts of nano silicon nitride, 3-6 parts of a boehmite / aluminum oxide and silicon dioxide composite material, 1-2 parts of a dispersing agent and 65-90 parts of a solvent, according to the lithium battery diaphragm coating provided by the invention, the wettability and absorptivity of a diaphragm to an electrolyte are remarkably improved, meanwhile, the lithium battery diaphragm coating also has excellent thermal stability, and the diaphragm can be effectively prevented from thermal shrinkage or melting under a high-temperature condition, so that the safety performance of a battery is remarkably enhanced.

The invention discloses a high-temperature-resistant, high-voltage-resistant and anti-breakdown capacitor base film and a preparation method thereof. The high-temperature-resistant, high-voltage-resistant and anti-breakdown capacitor base film is prepared from the following raw materials in parts by weight: 100 parts of polypropylene; 17 to 36 parts of polyvinylidene fluoride; 3-12 parts of enhanced and improved talcum powder; 1-6.5 parts of modified barium titanate; 1-6 parts of a cross-linking agent; 2-10 parts of a compatilizer; and 0.05-2 parts of an initiator. The capacitor base film is high in mechanical strength, and has excellent high temperature resistance, thermo-oxidative aging resistance, high voltage resistance and anti-breakdown performance; the enhanced and improved talcum powder is constructed by taking expanded layer modified talc as a carrier and titanium dioxide-carbon dot composite particles as a loading component and grafting and coating the organic matter, so that the defects of the talcum powder can be overcome, and the improvement effect of the talcum powder on heat resistance, high-voltage resistance and breakdown resistance can be fully exerted; meanwhile, the system can be endowed with excellent thermo-oxidative aging resistance.

The invention discloses a modification method of a PVDF (Polyvinylidene Fluoride) separation membrane, and belongs to the technical field of water treatment. The modification method provided by the invention comprises the step of impacting the PVDF separation membrane by adopting high-pressure liquid, so that high-pressure micro-droplets are in high-speed friction with the surface of the PVDF separation membrane. According to the modification method provided by the invention, the hydrophilicity, the surface potential and the dye retention rate of the PVDF separation membrane can be effectively improved.

The present invention relates to a lithium-ion battery diaphragm modified by high-temperature fluorine-containing liquid crystal polymer and polyvinylidene fluoride, and a preparation method and application thereof. The lithium-ion battery diaphragm of the present invention comprises a base diaphragm and a modified coating coated on the surface of the base diaphragm, wherein the modified coating comprises a fluorine-containing liquid crystal polymer and polyvinylidene fluoride. The present invention forms a modified coating by mixing and dissolving the two materials in a suitable solvent, which significantly improves the thermal stability, chemical stability, mechanical strength and ionic conductivity of the diaphragm, thereby improving the safety performance and cycle life of the battery.

The invention provides a high-barrier fresh-keeping low-temperature heat-sealing composite film and a manufacturing process and application thereof, the composite film sequentially comprises a heat-sealing layer, a barrier layer, a reinforcing layer and a surface treatment layer from the inner layer to the outer layer, and the layers are bonded through bonding layers. The heat-sealing layer is prepared from modified polyethylene, polypropylene and a heat-sealing auxiliary agent, and the barrier layer is made of a composite material of nano aluminum oxide, polyvinylidene fluoride and an ethylene-vinyl alcohol copolymer. The enhancement layer is a polyester film, and the surface treatment layer is subjected to corona treatment. The composite film is prepared through a specific manufacturing process, and the specific manufacturing process comprises the steps of preparation of the heat sealing layer and the blocking layer, compounding, curing treatment, surface treatment and the like. The composite film disclosed by the invention has excellent barrier property and low-temperature heat-sealing capability, is suitable for vacuum packaging or modified atmosphere packaging of foods, and effectively prolongs the fresh-keeping period and the shelf life of the foods.

The invention belongs to the technical field of sodium-ion batteries, and relates to sodium-ion battery positive electrode slurry and a preparation method thereof, and the sodium-ion battery positive electrode slurry comprises a positive electrode active material, a conductive agent, a binder, a dispersant, a slurry stabilizer and a solvent; the positive electrode active material is a transition metal layered oxide material, the conductive agent is one or a combination of more of conductive carbon black, ketjen black, conductive graphite and a carbon nanotube, the binder is polyvinylidene fluoride, the dispersant is polyvinylpyrrolidone, the slurry stabilizer is one or a combination of more of iron oxide, aluminum oxide, zirconium oxide and titanium boride, and the positive electrode active material is a positive electrode active material. The solvent is N-methyl pyrrolidone; in the slurry preparation step, a binder and a solvent are mixed and dissolved to prepare a glue solution; adding a conductive agent and a dispersing agent for dispersing to obtain a conductive adhesive; adding a positive active material and a slurry stabilizer, and dispersing to obtain final slurry; the invention can effectively solve the problem of slurry flocculation in the homogenizing process of the sodium ion battery positive electrode material.

The invention provides a PVDF (Polyvinylidene Fluoride) nanofiltration membrane constructed on the basis of microwave-enhanced bridging interfacial polymerization as well as a preparation method and application of the PVDF nanofiltration membrane. The method comprises the following steps: reacting PVDF powder with an organic alkali to prepare a modified film-forming solution, blade-coating the modified film-forming solution on a non-woven fabric supporting layer, placing the non-woven fabric supporting layer in an ethanol-water or methanol-water coagulating bath, and preparing a PVDF supporting film by virtue of assistance of an ice template; weighing the functionalized nano material and an amino silane coupling agent, performing ultrasonic dispersion, and adding a catalyst for reaction to obtain dispersion liquid; immersing a PVDF support membrane into the dispersion liquid to obtain a modified membrane; immersing the modified membrane into an aqueous solution containing an amine monomer and an organic solution containing an acyl chloride monomer, and carrying out microwave radiation. The interface reaction rate and selectivity are enhanced through the microwave excitation effect, and meanwhile, the hydrophilicity and reaction activity of the PVDF base membrane are cooperatively regulated and controlled, so that the separation efficiency and the anti-pollution capacity of the membrane are remarkably improved. The obtained PVDF nanofiltration membrane has high flux, high selectivity and excellent structural stability, and is suitable for efficient purification and resource recovery application in a complex water system.

The invention relates to a wide-range gradient microstructure ion capacitive pressure sensor and a preparation method thereof. The sensor comprises an outer wrapping layer and a sensor main body part, the sensor main body part is packaged in the outer wrapping layer; the sensor main body part is of a multi-layer combined structure and comprises a top polyimide film layer, a top copper electrode layer, a dielectric layer, a bottom copper electrode layer and a bottom polyimide film layer which are arranged in sequence; the dielectric layer is made of ionic gel, and the ionic gel is formed by mixing polyvinylidene fluoride-hexafluoropropylene and 1-ethyl-3-methylimidazoline bis (trifluoromethylsulfonyl) imide salt; the top polyimide film and the top copper electrode layer are tightly attached and fixed, the bottom polyimide film and the bottom copper electrode layer are tightly attached and fixed, and the dielectric layer is located between the top copper electrode and the bottom copper electrode. And one side, close to the top copper electrode, of the dielectric layer is provided with a uniformly-distributed gradient microstructure with height difference. According to the invention, the sensitivity of the sensor is kept at a high level in a wide range.

The invention discloses a lithium ion battery positive electrode material and a preparation method thereof, the lithium ion battery positive electrode material comprises an active substance, a conductive additive, a binder and a thermal stability additive, the active substance is # imgabs0 # with a layered structure, x + y + z = 1, 0.5 < = x < = 0.8, 0.1 < = y < = 0.3, 0.1 < = z < = 0.3, the conductive additive is a compound of a carbon nanotube and graphene, and the thermal stability additive is a mixture of a carbon nanotube and graphene. The binder is a mixture of polyvinylidene fluoride and sodium carboxymethyl cellulose, the thermal stability additive is a mixture of lithium phosphate and aluminum oxide, the sum of the mass fraction of the lithium phosphate and the mass fraction of the aluminum oxide in the thermal stability additive is 0.5-10%, and the mass fraction of the lithium phosphate is 0.5-5%. According to the lithium ion battery positive electrode material and the preparation method thereof, the stability of the positive electrode material at high temperature can be improved, the thermal runaway risk is reduced, and the cycle life of the battery is prolonged.

The invention discloses a lithium ion battery composite diaphragm, a preparation method and a lithium ion battery, and relates to the technical field of lithium ion batteries. The lithium ion battery composite diaphragm comprises a base membrane and a functional coating arranged on the negative electrode side of the base membrane, the functional coating sequentially comprises an ion conducting layer, a thermal barrier layer and a self-repairing layer from the position close to the base film to the position far away from the base film; wherein the base membrane is a polyimide and aramid nanofiber blended electrostatic spinning membrane; the ion conducting layer comprises a compound of a modified fast ion conductor and polyvinylidene fluoride-hexafluoropropylene; the thermal barrier layer comprises a cross-linked network of boron nitride nanosheets and polybenzimidazole; the self-repairing layer comprises polyurethane microspheres loaded with dynamic disulfide bonds. The composite diaphragm provided by the invention can remarkably inhibit a purple area on the surface of a negative electrode, and enhance high-temperature self-protection and interface self-repairing of the lithium ion battery, so that the cycle and safety performance of the lithium ion battery are remarkably improved.

The invention discloses a multifunctional composite hydrophobic membrane and a preparation method thereof, in the hydrophobic membrane, nano silicon dioxide, hydroxyl multi-walled carbon nanotubes and perfluorooctyl ethyl acrylate are polymerized to obtain a modified composite material, the modified composite material is added into a polyvinylidene fluoride-hexafluoropropylene copolymer, fibers are formed through an electrostatic spinning method, the fibers are deposited on a polyester net base lining, and the multifunctional composite hydrophobic membrane is prepared. Nano-silica and hydroxyl multi-walled carbon nanotubes are modified, agglomeration is effectively avoided, the hydrophobic membrane has good mechanical strength and toughness, and microcosmic multi-dimensional roughness of the surface of the membrane can be achieved by introducing an inorganic-organic nano hybrid material. Fluorine atoms in a perfluorooctyl ethyl acrylate structure have relatively low surface energy, so that the surface energy of the film can be remarkably reduced, the surface of the film has low surface energy and a rough structure, and the film is high in hydrophobicity and good in chemical stability.

The invention discloses an MXene / PVDF photo-thermal composite film for seawater evaporation, and belongs to the technical field of solar interface water vapor conversion. The photo-thermal composite film is prepared by the following steps: blending an MXene dispersion liquid and PVDF (Polyvinylidene Fluoride) to obtain a film casting liquid, and carrying out blade coating to prepare the film; the photothermal conversion material MXene is a dispersion liquid of Ti < 3 > C < 2 > T < x > in water; and the photothermal conversion material MXene is obtained by etching Ti3AlC2 by using HCl + LiF (HCl + LiF). The photo-thermal composite film is prepared by blending MXene and PVDF, the influence of introduction of MXene on the hydrophilic-hydrophobic property and photo-thermal conversion performance of the MXene / PVDF composite film is explored, MXene has good photo-thermal conversion performance and hydrophilicity, PVDF as a common film material has hydrophobicity, and the MXene / PVDF composite film has good photothermal conversion performance and hydrophilicity. And the two are combined, so that the composite film can automatically float on the water surface for interface photothermal conversion while absorbing water. The MXene / PVDF composite film is prepared by adopting a blade coating method, so that the whole process is relatively simple, the film structure characterization and the film performance test are convenient to carry out, and a theoretical and practical basis is provided for the subsequent construction and application of a seawater evaporator.

The invention discloses a microporous diaphragm for a low-electrical-impedance lithium battery and a preparation method of the microporous diaphragm. The diaphragm comprises: a base film layer, wherein the base film layer is of a microporous structure formed by biaxially stretching polypropylene and / or polyethylene; the surface of the base film layer is coated with the functional coating, and the functional coating contains mixed slurry of inorganic nanoparticles and a binder; the surface modification layer is formed by introducing a hydrophilic electrolyte group on the surface of the functional coating through plasma treatment or chemical grafting. The base membrane layer forms a uniform micropore structure through a two-way stretching process, the functional coating is formed by compounding nano silicon dioxide or aluminum oxide and polyvinylidene fluoride according to a specific proportion, a porous layer with gradient pore diameter is formed, the pore size of the porous layer is smaller than that of the base membrane layer, and efficient permeation of electrolyte is ensured. Electrolyte-philic groups such as sulfonic groups are introduced into the surface modification layer, so that the wettability of the diaphragm to an electrolyte is remarkably improved. During preparation, the base membrane is formed through melt blending, two-way stretching and pore-forming agent extraction, and then the functional layer is constructed through slurry coating and a low-temperature plasma treatment or sulfonation process. The diaphragm combines gradient aperture design, inorganic filler enhancement and surface chemical modification, and realizes low impedance, high thermal stability and excellent mechanical strength.

Disclosed in the present invention are an anti-aging fireproof power cable and a manufacturing method therefor, comprising: first, extruding an insulating material outside a conductor to form an insulating layer, thereby producing a wire core; stranding a plurality of wire cores into a cable core; then, extruding composite gel on the surface of the cable core to form a gel layer; forming a polyvinylidene fluoride coating on the surface of the gel layer by means of a plasma discharge technology; and finally, coating the surface of the polyvinylidene fluoride coating with an armor layer, thereby obtaining an anti-aging fireproof power cable. The power cable obtained in the present invention has excellent aging resistance and a good fireproof effect, can satisfy requirements for long-term use, and exhibits higher safety.

The invention provides a polyvinylidene fluoride-based nanofiber yarn wave-absorbing fabric as well as a preparation method and application thereof, and belongs to the technical field of preparation of wave-absorbing composite materials. The preparation method comprises the following steps: preparing nanofiber yarns or nanofiber core-spun yarns by adopting a conjugate electrostatic spinning technology, directly adding a conductive substance into a spinning solution to form conductive nanofibers, and further coating the nanofiber yarns or the nanofiber core-spun yarns with a PDA shell layer to improve the wear resistance and reduce silver nanoparticles in situ; finally, the yarns are woven into fabric through a weaving or knitting technology, and the fabric is applied to the fields of buildings, electromagnetic protective clothing, flexible electronics and the like. Compared with an existing microwave absorbing material, the fabric-based material is light in weight and good in mechanical flexibility and processability. Fabrics formed of nanofiber yarns or nanofiber core spun yarns facilitate the induction of interfacial polarization and multiple reflections, and can deeply design material properties. The material provided by the invention has better wear resistance, wearability and microwave absorption performance, and is suitable for actual production and application.

The invention relates to the field of thin film capacitors, and discloses a composite thin film and a preparation method and application thereof. The composite film is formed by thermal crosslinking of a high-temperature dielectric material and a piezoelectric ferroelectric polymer. Wherein the high-temperature dielectric material is polyimide or polyetherimide; the piezoelectric ferroelectric polymer is selected from cyanoethyl cellulose or polyvinylidene fluoride-trifluoroethylene-chlorofluoroethylene (P (VDF-TrFE-CFE)), polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (P (VDF-TrFE)), and the piezoelectric ferroelectric polymer is selected from polyvinylidene fluoride-trifluoroethylene (P (VDF-TrFE)) and polyvinylidene fluoride-trifluoroethylene (P (VDF-TrFE)); wherein the mass ratio of the high-temperature dielectric material to the piezoelectric ferroelectric polymer is 1: (0.00036-0.1). When the composite film is applied to a film capacitor, the effects of high dielectric constant and high breakdown strength, and improvement of thermal stability, thermal conductivity and energy storage performance can be achieved.

The invention discloses an anti-fouling high-voltage electrocatalytic activity polyvinylidene fluoride uranium adsorption material and a preparation method thereof, and belongs to the field of uranium adsorption materials.According to the adsorption material, dimethyl sulfoxide serves as a solvent, polyvinylidene fluoride serves as a substrate material, amidoximation polyacrylonitrile serves as a modified molecule, and B i4T i3O12 / SnO2 serves as filler, and after physical blending, the adsorption material is prepared into the high-voltage electrocatalytic activity polyvinylidene fluoride uranium adsorption material. The composition is prepared by a freezing phase inversion method. The adsorbing material disclosed by the invention has an excellent removal rate on uranyl ions and has an excellent antibacterial property.

The invention relates to the field of electromagnetic functional composite materials, and particularly discloses a multi-layer composite structure flexible frequency selective surface material and a preparation method thereof. The ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced band-pass frequency selection array sequentially comprises an acrylic acid polyvinylidene fluoride organic polymer coating environment-resistant layer, a metal oxide organic film isolation layer, an ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced layer, a band-pass frequency selection layer and a packaging protection layer from top to bottom, and the band-pass frequency selection layer is a hexagonal / circular ring nested band-pass frequency selection pattern array. The packaging protection layer is formed by printing a conductive coating composed of conductive filler / polymer resin matrix, and the packaging protection layer is an ink coating. The flexible frequency selective surface material has the characteristics of light weight, high strength, salt fog / rain / ultraviolet and other severe environments, frequency selective wave transmission and multiple functions, has good gas barrier property, is beneficial to maintaining the shape of an inflatable hangar made of a skin and ensuring normal operation of radar equipment, and has good practical engineering application value.

The invention discloses a polyion liquid / polyvinylidene fluoride-hexafluoropropylene-based solid electrolyte with a microscopic liquid phase and a preparation method and application thereof, and the preparation method comprises the following steps: adding a lithium salt into N-methyl-2-pyrrolidone, and stirring until the lithium salt is completely dissolved; then adding imidazolyl polyion liquid to prepare a solution A; adding polyvinylidene fluoride-hexafluoropropylene into N-methyl-2-pyrrolidone to prepare a solution, adding the solution into the solution A, continuously stirring until the solution is fully dissolved to obtain a precursor solution of the solid electrolyte, casting the precursor solution onto a polytetrafluoroethylene mold, and carrying out vacuum drying to obtain the solid electrolyte. And the polyvinylidene fluoride-hexafluoropropylene polymer-based solid electrolyte added with the imidazolyl polyion liquid is prepared by adding the imidazolyl polyion liquid into the polyvinylidene fluoride-hexafluoropropylene polymer-based solid electrolyte. The polymer-based solid electrolyte with a microscopic liquid phase is obtained through an electrolyte preparation process which is mild in condition, simple to operate and easy for large-scale production, and the solid electrolyte has good conductivity and mechanical properties.

The invention discloses a silicon dioxide reinforced high-hydrophobicity polyvinylidene fluoride membrane as well as a preparation method and application thereof, SiO2 nanoparticles are taken as a mechanical reinforcing agent and a structure regulator and are directly added into a membrane casting solution system, and solid-liquid phase separation is preliminarily induced on the surface of a primary membrane in combination with non-solvent spraying ethanol, so that the high-hydrophobicity PVDF membrane is successfully prepared. A unique multi-stage micro-nano structure consisting of mutually connected spherocrystals is constructed on the surface of the membrane, the hydrophobicity, aperture, porosity and mechanical property of the membrane are effectively improved, and the membrane shows excellent and stable separation performance in performance tests of seawater desalination and erythritol concentration, and has good application prospects in seawater desalination and erythritol concentration. The method shows huge application potential in the fields of wastewater treatment, food production and the like.

A preparation method for a conductive carbon nanotube-polyvinylidene fluoride composite hollow fiber membrane, which preparation method comprises the following steps: (1) formulation of a spinning solution, which involves: adding carboxylated carbon nanotubes and a dispersing agent to a solvent, stirring the mixture at 40-80ºC to uniformly disperse the carbon nanotubes, then adding polyvinylidene fluoride, and then continuously stirring same to completely dissolve polyvinylidene fluoride, so as to obtain a spinning solution; and (2) preparing a carbon nanotube-polyvinylidene fluoride composite hollow fiber membrane by means of wet spinning, wherein the hollow fiber membrane is subjected to conductive encapsulation and connection to construct an electrochemical coupling membrane separation assembly that can achieve the combination of an electrochemical effect and a membrane separation function, thereby improving the anti-pollution capacity of a separation membrane.

The invention belongs to the technical field of lithium battery materials, and particularly relates to an integrated positive electrode / solid-state electrolyte sheet, a preparation method thereof and application of the integrated positive electrode / solid-state electrolyte sheet in a solid-state lithium battery. When the integrated positive electrode / solid electrolyte sheet provided by the invention is prepared, polyvinylidene fluoride-hexafluoropropylene is used as a flexible framework, poly (1, 3-dioxolame) is used as an additive, and an ionic liquid is used as an ionic conductor, solid electrolyte slurry is prepared by mixing, then the slurry is directly coated on the positive electrode sheet, and the integrated positive electrode / solid electrolyte sheet is obtained. The thickness of the solid-state electrolyte layer in the obtained integrated positive electrode / solid-state electrolyte sheet is less than 20 [mu] m, so that the requirement on high energy density of a solid-state lithium battery in industry is met. Meanwhile, the integrated positive electrode / solid-state electrolyte sheet can be randomly bent under the condition of keeping high ionic conductivity and mechanical modulus, so that the solid-state lithium battery assembled by adopting the electrolyte sheet at room temperature has higher specific capacity and good cycling stability, and has good popularization and application prospects in high-energy-storage lithium batteries.

The invention discloses a nanoparticle / polyvinylidene fluoride composite piezoelectric gain photocatalytic antibacterial film and a preparation method and application thereof.The preparation method comprises the steps that a polyvinylidene fluoride solution serves as a core layer spinning solution, and photocatalytic nano sol serves as a skin layer spinning solution; and carrying out coaxial electrostatic spinning on the polyvinylidene fluoride solution and the photocatalytic nano sol to prepare the nano particle / polyvinylidene fluoride composite piezoelectric gain photocatalytic antibacterial film. According to the preparation method disclosed by the invention, nano-scale photocatalytic sol is fixed on the surface of micron-scale polyvinylidene fluoride in one step by utilizing an electrostatic spinning technology, so that the polyvinylidene fluoride is prevented from coating effective components, and the effective components are also prevented from blocking holes of polyvinylidene fluoride fibers; effective separation and directional migration of electrons and holes of sol on the surface are effectively promoted, and the capacity of photocatalytic nano sol for removing biological aerosol is improved. The preparation method is simple in industry, low in energy consumption and easy for large-scale production.

The invention relates to a preparation technology of a gel polymer lithium ion battery cell electrolyte, and belongs to the field of battery preparation technologies, the preparation technology comprises the following steps: mixing methacrylate monomers and silane monomers according to a mass ratio of 3: 1-5: 1, adding 1-3% of an initiator, and carrying out prepolymerization at 60-80 DEG C for 1-3 h to prepare a prepolymer solution; mixing with a non-aqueous solvent containing lithium hexafluorophosphate according to a mass ratio of (1: 4)-(1: 6) to form a precursor mixed solution, and controlling the injection rate to be 1.5-2.5 g / Ah to a gap between a battery cell pole piece and a diaphragm; after standing for 2-4 hours at the vacuum degree of less than or equal to-0.08 MPa, curing for 3-6 hours at the temperature of 60-70 DEG C to form a gel polymer electrolyte; the wettability is improved through pole piece surface hydrophilic treatment, 1-5% of vinylene carbonate is added to optimize an SEI film, the prepolymerization temperature fluctuation is controlled to be smaller than or equal to + / -2 DEG C through microwave-assisted heating, the pressure of 0.2-0.5 MPa is applied after injection to promote uniform permeation, a polyvinylidene fluoride coating of 5-10 microns is coated after curing to enhance protection, and the interface performance is ensured through an alternating-current impedance test.

A piezoelectric sensing module includes a polyvinylidene fluoride (PVDF) piezoelectric film, a first electrode layer that includes multiple receiver electrodes arranged in a first pattern enabling a sensing of a position of an input object on a touch surface using the PVDF piezoelectric film, and a second electrode layer that includes at least one common electrode. The PVDF piezoelectric film is arranged between the first electrode layer and the second electrode layer, with the second electrode layer between the PVDF piezoelectric film and the touch surface.

The invention discloses a titanium lithium aluminum phosphate solid electrolyte polymer interface modification method and a preparation method thereof. The method comprises the following steps: firstly, selecting LITFSI (lithium ion conductor), PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) and DMSO (dimethyl sulfoxide) liquid, and mixing to form PVDF-HFP-based polymer mixed liquid; then, the PAN film doped with titanium lithium aluminum phosphate powder is uniformly coated with the mixed solution through a press coating method, and the PVDF-HFPPAN film is obtained through drying treatment. And cutting the membrane, placing the cut membrane on two sides of a ceramic chip solid electrolyte, assembling an all-solid-state battery, activating at 40-80 DEG C until the polymer is attached to a metal lithium negative electrode and the surface of the solid electrolyte in a gel state, and cooling to finally obtain the solid electrolyte with a PVDF-HFPPAN coated LATP coated PVDF-HFPPAN sandwich structure. The modified solid-state electrolyte membrane can effectively inhibit the interface reaction of LATP on the lithium negative electrode side and enhance the wettability of the positive and negative electrode interface, thereby meeting the cycle performance requirement of the solid-state battery under the normal temperature condition.

The invention discloses an anti-pollution modified hollow fiber membrane and a preparation method and application thereof.The anti-pollution modified hollow fiber membrane can be tightly combined with a zwitterionic polymer material modified nano-antibacterial material, and is prepared from, by weight, 8-30% of polyvinylidene fluoride (PVDF) / polysulfone / polyethersulfone, 0.1-15% of a modified material, 0.1-10% of an antioxidant and the balance water. According to the present invention, the prepared hollow fiber membrane has characteristics of excellent pollution resistance, no filament breaking, and application in wastewater treatment, pollution control, water resource comprehensive utilization, food processing, medicine purification, and other aspects, and the prepared hollow fiber membrane has characteristics of excellent pollution resistance, no filament breaking, and can be used in the fields of wastewater treatment, pollution control, water resource comprehensive utilization, food processing, medicine purification, and the like.

The invention discloses an aircraft shell surface quality detection method. According to the method, a passenger cabin pressure difference curve and a shell outer surface temperature curve are calculated to obtain a pressure difference change node and a temperature difference change node respectively, and then partitioning is carried out to obtain phase thermoelastic coupling partitions; when a temperature difference change node reaches a phase change threshold value, performing beta-phase to alpha-phase transformation on the polyvinylidene fluoride microcapsule premixed in the finish paint, and forming a polarized memory cavity at a defect cementing position; when a voltage difference change node reaches a peak value, triggering a polarized memory hole to release charges, exciting a high-order thin film elastic wave, and performing integer ratio phase locking on the high-order thin film elastic wave and a natural vibration wave of a machine body to obtain a defect harmonic signal; carrying out acoustic-mechanical coupling calculation according to the amplitude of the defect harmonic signal to obtain a virtual work increment, and recording the virtual work increment to a damage matrix; and performing multi-leg accumulation calculation on the virtual work increment, and outputting a defect early warning signal when an accumulation value exceeds a material fatigue critical value. According to the invention, the hidden fatigue defect of the surface of the aircraft shell under the dynamic load can be detected.

The invention provides a high-temperature-resistant fast-charging PVDF-HFP-based all-solid-state electrolyte membrane as well as a preparation method and application thereof, and relates to the technical field of power batteries. The preparation method comprises the following steps: uniformly mixing a polyvinylidene fluoride-hexafluoropropylene copolymer, a lithium salt and a polar solvent to obtain a PVDF-HFP solution; then uniformly mixing the PVDF-HFP solution with a cross-linking agent and a 2, 2-bis (4-allyloxy-3, 5-dibromophenyl) propane monomer, so as to obtain a precursor solution; uniformly mixing an initiator with the precursor solution to obtain a reaction solution; and finally, coating a substrate with the reaction solution, and heating at 70-80 DEG C for 12-16 hours to obtain the high-temperature-resistant fast-charging PVDF-HFP-based all-solid-state electrolyte membrane. When the high-temperature-resistant and fast-charging PVDF-HFP-based all-solid-state electrolyte membrane is applied to a lithium metal battery, the thermal safety and the high-temperature-resistant and fast-charging performance can be remarkably improved.