1725 results about "Polyvinylidene fluoride" patented technology

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 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 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 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.

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 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 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.

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 diaphragm and a preparation method thereof and a lithium ion battery, the diaphragm comprises a base membrane layer and a composite functional layer, the composite functional layer comprises hydrophobic SiO2 aerogel modified by a hydrophobic agent, a conductive ion polymer and a solid electrolyte, and the composite functional layer respectively accounts for 3-12wt%, 0.5-1.0 wt% and 0.5-1.5 wt% of the total mass of the diaphragm; the hydrophobic agent comprises trimethylchlorosilane, hexamethyldisilazane, perfluorooctyltriethoxysilane, polyvinylidene fluoride, polydimethylsiloxane and the like, the conductive ionic polymer comprises polyvinylpyrrolidone, lithium polymethacrylate, lithium polystyrene sulfonate, polyacrylamide and the like, and the solid electrolyte comprises lithium lanthanum titanium oxide, lithium lanthanum zirconium oxide, lithium lanthanum zirconium tantalum oxide and the like. The wettability is improved by the high porosity of the hydrophobic SiO2 aerogel, the stability and strong conductivity of a physical conductive network of the solid electrolyte and the ion affinity and amphoteric binding capacity of the conductive ion polymer are optimized, the electrochemical performance and thermal stability of the interface are optimized, and comprehensive optimization of the thermal-electric-interface performance of the diaphragm is realized through combination.

The invention provides a rigid-flexible metal-organic framework diaphragm with high selectivity as well as a preparation method and application of the rigid-flexible metal-organic framework diaphragm. Through a seed secondary growth strategy, the problems that MOF particles are easy to fall off and are incompatible with a substrate film are successfully avoided. On one hand, grain seeds embedded in the polyvinylidene fluoride (PVDF) substrate film in advance provide stable anchoring points for growth of MOF, and MOF particles are not prone to falling off due to the high adhesive force of the grain seeds. The high Young modulus of the MOF crystal also effectively improves the thermal shrinkage resistance of the diaphragm, the excellent flexibility of PVDF is complementary with the diaphragm in mechanical property, and the battery diaphragm shows excellent mechanical property and thermal stability due to the rigid-flexible combination strategy. The invention provides an efficient diaphragm construction strategy for developing a lithium metal battery with long cycle life and high safety, and shows a wide application prospect in a next-generation high-safety battery.

The utility model relates to a system for reducing the acid value of hydrolysate in the separation and washing process of dimethyl dichlorosilane hydrolysate. Comprising three stages of coalescers, dimethyl dichlorosilane acidic hydrolysate enters the system from the first stage of coalescer, process water enters the system from the third stage of coalescer, the acidic hydrolysate and diluted hydrochloric acid or process water are mixed in each stage of coalescer, oil-water two-phase separation is completed through multiple times of washing and coalescence, and meanwhile the acid value of the hydrolysate is reduced; each stage of coalescer comprises two static mixers connected in series, a group of prefilters and a large coalescer, the coalescer is Z-shaped, and four stages of filter elements are arranged in each stage of coalescer. Through repeated tests, a modified polyvinylidene fluoride filter element of Pall Company is finally selected, and after continuous three-stage coalescer treatment, the acid value of dimethyldichlorosilane hydrolysate can be reduced to 10 PPM or below.

The invention discloses positive electrode slurry for preventing formation of gel and a preparation method of the positive electrode slurry. The method comprises the following steps: S1, drying a positive electrode active material under the protection of inert gas; s2, carrying out surface modification by using a functionalized silane coupling agent; s3, drying the conductive agent under a high-temperature vacuum condition; s4, under the protection of inert gas, lithium alkyl sulfonate, a polyhydric alcohol chelating agent and polyvinylidene fluoride are subjected to a reaction to prepare a modified binder; s5, mixing and dispersing the modified active material, the conductive agent, the modified binder and the acidic buffer agent in a low-dew-point drying chamber; s6, performing ultrasonic treatment on the slurry under a vacuum condition; and S7, adding a cross-linked fluorosilane coupling agent, mixing at a low speed and precisely filtering to obtain the anti-gel positive electrode slurry. According to the invention, through a multi-synergistic anti-gel mechanism, the problem that the positive electrode material slurry is easy to form gel is solved, and the prepared slurry has excellent stability, rheological property and coating performance, so that the electrochemical performance of the battery is improved.

The invention discloses a preparation method and application of a composite PVDF-HFP and polylysine nanofiber diaphragm, and belongs to the technical field of lithium batteries. The composite material is prepared by blending polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and polylysine and then carrying out an electrostatic spinning process. The PVDF-HFP is utilized to provide excellent mechanical strength and chemical stability, rich polar amino functional groups in a polylysine molecular chain are utilized to improve the lyophilic property of the membrane, and anions in an electrolyte are fixed through an intermolecular acting force, so that the transference number of lithium ions is increased, and the lithium ions are induced to be uniformly deposited. The nanofiber membrane combines the characteristics of PVDF-HFP and polylysine, has high porosity, good thermal stability and excellent interface compatibility, can effectively inhibit the growth of lithium dendrites and prevent the diaphragm from being punctured, and can significantly prolong the cycle life and improve the safety performance of the lithium metal battery when being applied to the lithium metal battery.

The invention belongs to the field of flexible piezoelectric polymer materials, and discloses a polyvinylidene fluoride based ferroelectric polymer and a preparation method thereof. The preparation method comprises the following steps: (1) adding an inorganic alkaline reagent into a polyvinylidene fluoride-trifluoroethylene ferroelectric polymer solution, carrying out dehydrofluorination and nucleophilic addition-elimination reaction to generate a polymer with an enol structure, and then washing, precipitating and purifying a reaction product; and (2) re-dissolving by using an organic solvent, then forming a film by using a tape casting method, and carrying out ketone-enol tautomerization reaction in the film forming process of the tape casting method to finally prepare the polyvinylidene fluoride based ferroelectric polymer film. According to the effective modification and preparation method disclosed by the invention, an enol structure is promoted to be converted into a more stable ketone structure through a ketone-enol tautomerization reaction by utilizing a high-temperature environment in a film forming process, so that C = O double bonds are introduced into a polymer chain, and the piezoelectric property of the polymer is remarkably enhanced.

A cover window includes a window substrate having a first hardness and including polyvinylidene fluoride (PVDF), and a hard coating layer on at least one surface of the window substrate and having a second hardness which is greater than that of the window substrate.

The invention relates to the technical field of inorganic material preparation and new energy materials, and particularly discloses a lithium metal battery composite solid electrolyte as well as a preparation method and application thereof. Lithium niobate with high lithium ion conductivity and high dielectric constant is used as an inorganic filler, polyvinylidene fluoride-co-hexafluoropropylene is used as a polymer matrix, and the lithium metal battery composite solid electrolyte is prepared. The lithium metal battery solid electrolyte with a continuous lithium ion transport path is constructed through a freeze casting technology, the dielectric constant of the solid electrolyte is effectively improved by adding the dielectric inorganic filler lithium niobate, lithium salt dissociation is promoted, preparation of the modified electrolyte can be simply completed on a large scale, industrial expansion is facilitated, coulombic efficiency is improved, and the lithium metal battery solid electrolyte is suitable for industrial production. According to the present invention, the lithium metal battery electrolyte meets the industrial requirement on the high lithium utilization rate, the lithium negative electrode can be well protected, the cycle life of the lithium electrode can be improved, the battery electrolyte and the lithium electrode show the good interface compatibility and the good cycle stability, and the new feasible way is provided for the application of the lithium metal battery.

The invention belongs to the field of water treatment, and particularly relates to a graphene-based quinone mediator membrane as well as a preparation method and application thereof. The graphene-based quinone mediator membrane comprises a membrane matrix, and graphene, amino imidazopyridine and humus which are dispersed in the membrane matrix, the membrane substrate is made of polyvinylidene fluoride / butadiene, the polyvinylidene fluoride / butadiene is a random copolymer of polyvinylidene fluoride and butadiene, and an anthraquinone modification unit is bonded on a butadiene structural unit of the random copolymer. The graphene-based quinone mediator membrane provided by the invention has very high initial denitrification rate and over-time denitrification rate.

The invention discloses a thermally stable gas diffusion layer material and a fuel cell, and relates to the field of fuel cells. When the heat-stable gas diffusion layer material is prepared, short-cut polyacrylonitrile carbon fibers are subjected to papermaking and then cured, and 3-aminothiophene is oxidized and grafted to prepare a modified carbon paper base layer; the preparation method comprises the following steps: carrying out a reaction on a single-layer graphene oxide nanosheet, 6-amino-2-mercaptobenzothiazole and 3-aminoethyl thiophene to prepare a modified single-layer graphene oxide nanosheet; the preparation method comprises the following steps: reacting polyvinylidene fluoride powder, 3-allyl thiophene and single-ended vinyl silicone oil to prepare a modified polyvinylidene fluoride emulsion; and uniformly mixing the modified single-layer graphene oxide nanosheet, a modified polyvinylidene fluoride emulsion and isopropanol, spraying on the modified carbon paper base layer, and reacting with 3, 4-ethylenedioxythiophene to prepare the thermally stable gas diffusion layer material. The thermally stable gas diffusion layer material prepared by the method has excellent porosity, thermal stability, conductivity and corrosion resistance.

The embodiment of the invention provides a polymer binder, a preparation method thereof and an all-solid-state sulfide lithium battery. The polymer binder is a modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, and chlorine in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer is partially or completely substituted by bromine and / or iodine; in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, the molar ratio of a corresponding repeating unit of polyvinylidene fluoride to a corresponding repeating unit of trifluorochlor oethylene is (1-9): (9-1); in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, the weight of chlorine is a, the weight of bromine and / or iodine is b, and b / (a + b) * 100% is equal to 1%-100%. The technical effect of improving the cycling stability and safety of the battery is achieved, and then the technical problems that when a traditional binder is applied to the all-solid-state sulfide lithium battery, the interface is unstable, the binding power is insufficient, and the traditional binder reacts with electrolyte are solved.

The invention discloses a multi-layer flexible radiation cooling composite diaphragm which structurally comprises a flexible base layer film, and a SiO2 inorganic coating, a first layer of polyvinylidene fluoride (PVDF), a nano-silver layer deposited by magnetron sputtering and a second layer of PVDF which are sequentially coated to form a base layer film / SiO2 / PVDF / Ag / PVDF sandwich structure. The SiO2 layer is prepared through a sol-gel method, the surface roughness is smaller than 2 nm, and the visible light transmittance is larger than 95%; the thickness of the silver layer is 50 + / -5 nm, and the total thickness of SiO2 / PVDF / Ag does not exceed 150 nm. According to the composite diaphragm, ultraviolet reflection, visible light high transmission (greater than 92%) and near-infrared high reflection (greater than 88%) are realized through spectrum selective regulation and control, and meanwhile, SiO2 and PVDF synergistically enhance the infrared emissivity of an atmospheric window wave band (8-13 [mu] m). The flexible PET base material is combined with the PVDF interlayer design to restrain silver layer oxidation and interface stripping, the recovery rate is larger than 95% after 1000 times of bending circulation, and the NIR reflectivity attenuation is smaller than or equal to 5%. The composite diaphragm disclosed by the invention has the advantages of high light transmission, efficient cooling, excellent flexibility and long-term stability, and is suitable for flexible scenes such as agricultural greenhouses and the like.

The application discloses a preparation method of a hydrophilic oil-water separation anti-pollution membrane and the anti-pollution membrane and application thereof, and prepares MNRs material; the MNRs material is dispersed in dimethylacetamide, is uniformly stirred, polyvinylpyrrolidone is added, and stirring is continued, and a first mixture is obtained through ultrasonic treatment; the first mixture is mixed with polyvinylidene fluoride to obtain a second mixture, and the second mixture is stirred; the treated second mixture is dip-coated on a carrier, the dip-coated carrier is treated in deionized water to obtain an ultrafiltration membrane; the ultrafiltration membrane is soaked in a tea polyphenol solution with a Tris-HCl buffer solution, and is shaken to obtain the hydrophilic oil-water separation anti-pollution membrane. The hydrophilic oil-water separation anti-pollution membrane has excellent separation efficiency and flux recovery rate for four different oil-water mixtures of kerosene, gasoline, edible oil and n-hexane. The preparation process of the oil-water separation membrane is simple, the cost is low, and the reaction condition is mild; when the oil-water separation membrane is applied to organic wastewater separation, the oil-water separation membrane has the advantages of high efficiency, good removal performance and good recycling performance.

The invention relates to the technical field of flexible electronic sensing, and particularly discloses a composite fiber membrane-based capacitive flexible pressure sensor integrated system and a preparation method thereof. The sensor is composed of a composite fiber membrane sensitive layer, an interlayer type electrode structure, a multi-channel signal acquisition module and an intelligent data processing system. Wherein the composite fiber membrane is prepared through an electrostatic spinning technology, polyvinylidene fluoride serves as a matrix, ionic liquid with the mass ratio of 40%-70% is evenly dispersed, a three-dimensional porous structure is formed, and a pressure signal is converted into capacitance change through the double-electric-layer capacitance effect; the signal acquisition module adopts a high-precision capacitance digital converter to cooperatively work with a microcontroller, 9-channel parallel data acquisition is realized, the resolution reaches 6aF, and data is transmitted through an anti-interference bus protocol; and the data processing system dynamically analyzes the pressure-capacitance relationship based on an exponential function model, suppresses noise to be below 0.1 aF RMS in combination with a filtering algorithm, and synchronously generates a visual pressure distribution map.

The invention discloses a preparation method of a super-hydrophilic PVDF (polyvinylidene fluoride) microfiltration membrane, belongs to the technical field of filter membrane processing, and is used for solving the technical problem that the hydrophilic performance and flux of a microfiltration membrane in the prior art need to be further improved. The preparation method comprises the following steps: putting modified PVDF, acetone, N, N-dimethylformamide and an auxiliary additive into a reaction kettle, and uniformly mixing to obtain a mixed solution; the preparation method comprises the following steps: preparing modified polyolefin from modified graphene and ethylene-co-maleic anhydride, carrying out a polymerization reaction on the modified polyolefin and PVDF subjected to a dehydrogenation fluorination reaction to obtain modified PVDF, preparing a membrane from the modified PVDF, a solvent and an auxiliary additive through a phase inversion method, and further carrying out dipping treatment to obtain the PVDF / PVDF composite membrane. The hydrophilic performance and flux of the PVDF micro-filtration membrane are improved, and the mechanical performance of the PVDF micro-filtration membrane is also improved.

The invention relates to a water treatment and membrane separation technology, and provides an integrated catalytic separation membrane, a preparation method thereof, and a water treatment method and system. According to the membrane, polyvinylidene fluoride is used as a continuous phase to form a porous matrix, and cerium dioxide is embedded and fixed in a mode of uniform dispersion in a membrane body in a phase inversion membrane forming process; in the presence of illumination and peroxysulfate, active species are generated through in-situ activation on a membrane-water interface, and membrane separation is completed synchronously. The water treatment method comprises the following steps: adding peroxymonosulfate or peroxydisulfate into a water body to be treated, and filtering through the membrane under illumination; the photothermal effect generated by organic matter degradation intermediates in operation inhibits membrane pollution and maintains flux. According to the invention, short-range coupling of active sites and mass transfer channels is realized, the medicament and energy utilization rate is improved, the coating stripping and metal dissolution risk is reduced, and the method is suitable for drinking water pretreatment, reclaimed water deep treatment and treatment of water containing natural organic matters / humic acid.

The invention discloses a composite hydrophobic fiber membrane based on a friction nano-generator and a preparation method of the composite hydrophobic fiber membrane. The composite hydrophobic fiber membrane is composed of a polyvinylidene fluoride nanofiber membrane, boracite particles, hydrophobic nanoparticles and polyvinylidene fluoride microspheres. The boracite particles are embedded in fibers of the polyvinylidene fluoride nanofiber membrane, and the hydrophobic nanoparticles are uniformly attached to the polyvinylidene fluoride microspheres and the polyvinylidene fluoride nanofiber; the hydrophobic nano particles are titanium dioxide nano particles or zirconium dioxide nano particles. The preparation method comprises the following steps: dispersing boracite powder and polyvinylidene fluoride powder into N, N-dimethylformamide to prepare an electrostatic spinning solution; the preparation method comprises the following steps: dispersing hydrophobic nanoparticles and polyvinylidene fluoride powder into N, N-dimethylformamide to prepare an electrostatic spraying solution; the composite hydrophobic fiber membrane is prepared through synchronous electrostatic spinning and electrostatic spraying. The problem that a modified polyvinylidene fluoride fiber membrane friction nanometer generator is low in output electrical performance in a high-humidity environment can be solved.

The invention discloses a preparation method of a catalytic membrane for organic wastewater treatment, which comprises the following steps: dissolving polyvinylidene fluoride (PVDF), a pore-forming agent and plant polyphenol in an organic solvent, and stirring to obtain a membrane casting solution, wherein the PVDF accounts for 12-20%, the pore-forming agent accounts for 1-8%, and the plant polyphenol accounts for 1-6%; standing and defoaming the membrane casting solution, blade-coating the membrane casting solution on a support body to form a membrane, and performing phase inversion in a water bath to obtain the plant polyphenol modified PVDF membrane; and immersing the membrane in a 3-10 mmol / L metal chloride aqueous solution, and reacting at 40-80 DEG C for 6-48 hours, so that metal ions and polyphenol are coordinated and crosslinked, and a metal-polyphenol network layer is formed on the surface of the membrane and the inner walls of membrane pores, thereby obtaining the catalytic membrane. The catalytic membrane can activate peroxymonosulfate (PMS) and synergistically degrade organic pollutants in water under a differential pressure filtration working condition, active sites are anchored stably, metal precipitation is reduced, and flux and catalytic efficiency are both considered.

The application belongs to the field of separation and specifically relates to a cellulose / PVDF electrostatic spinning oil-water separation membrane and a preparation method thereof. The preparation method comprises the following steps: S1: preparing cellulose stearate; S2: mixing cellulose stearate obtained in step S1 and polyvinylidene fluoride (PVDF) prepared into solutions respectively to obtain a spinning solution; and S3: defoaming the spinning solution obtained in step S2 and then electrostatic spinning to obtain a cellulose stearate / polyvinylidene fluoride (PVDF) hydrophobic oleophilic oil-water separation membrane. The mixed electrostatic spinning nanofiber membrane has better mechanical properties, and due to the addition of modified cellulose, the nanofiber membrane has greater separation flux, higher separation efficiency and greater porosity.

A device and method for representing the foam porosity state of foamed lightweight soil with self-adjusting beams, and relates to the technical field of sound absorption coefficients measurement; the device includes a standing wave tube, a plurality of polyvinylidene fluoride piezoelectric films, a sensor, an exciter, a push-pull handle, an adjustable telescopic tube, a foamed lightweight soil detection material, a charge amplifier, a data memory, a data adapter, a signal generator, an adaptive power amplifier board, and a PC computer; the device of the invention has low cost, long service life, high measurement accuracy, relatively simple production process, and can be applied to different scenarios.

The invention relates to the technical field of oil-water separation, in particular to a super-hydrophobic foam copper sheet, a preparation method and application thereof and a foam copper box. The invention provides a super-hydrophobic foam copper sheet. The super-hydrophobic foam copper sheet comprises a foam copper sheet body and a hydrophobic coating located on the surface of the foam copper sheet body. The hydrophobic coating is obtained by calcining preparation raw materials including a fluorinated ethylene-propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silicon dioxide nanoparticles. The super-hydrophobic foam copper sheet can realize continuous and rapid oil absorption, and has excellent oil-water separation efficiency.

The present invention discloses a method for preparing a glass fiber diaphragm modified with a bismuth-based metal organic framework material, comprising: (1) using bismuth nitrate pentahydrate and trimesic acid as raw materials, and synthesizing a bismuth-based metal organic framework material by solvent thermal reaction; (2) adding the bismuth-based metal organic framework material prepared in step (1) and polyvinylidene fluoride to an N-methylpyrrolidone solution for mixing; (3) modifying the mixed solution obtained in step (2) onto a glass fiber diaphragm by a suction filtration method, and obtaining a glass fiber diaphragm modified with a bismuth-based metal organic framework material after drying. The present invention also discloses a glass fiber diaphragm modified with a bismuth-based metal organic framework material obtained by the above-mentioned preparation method and its application in a zinc ion battery. The glass fiber diaphragm modified with a bismuth-based metal organic framework material provided by the present invention can improve its electrochemical performance when applied to a zinc ion battery, thereby solving the problem of poor cycle performance of ordinary glass fiber diaphragms applied to aqueous batteries.