22 results about "Ferroelectric polymers" patented technology

The invention discloses a ferroelectric composite fiber, a battery diaphragm, a battery piece, a lithium ion battery and a preparation method thereof, and belongs to the technical field of batteries. The ferroelectric composite fiber comprises a base membrane, and an organic ferroelectric polymer, inorganic ferroelectric nanoparticles and interface functional molecules which are loaded on the base membrane, the interface functional molecule is 1-azaphenol thiazine and / or a derivative thereof. In addition, the invention also provides a preparation method of the ferroelectric composite fiber. In addition, the invention also provides a battery diaphragm, a battery piece and a lithium ion battery. The ferroelectric composite fiber provided by the invention synchronously solves the two problems of ion transport kinetics and electrode interface stability in one-time film formation.

The application belongs to the technical field of flexible piezoelectric materials, and discloses a grafted ferroelectric polymer thin film with a high piezoelectric coefficient and a preparation method thereof, wherein the preparation method comprises the following steps: obtaining a polymer solution by selecting a polyvinylidene fluoride-based ferroelectric polymer; adding a grafting agent reagent to the polymer solution and uniformly mixing to obtain a mixed solution; uniformly casting the mixed solution on the surface of a glass substrate, heating in an oven to volatilize the solvent, then increasing the temperature of the oven to perform a grafting reaction to obtain a grafted thin film; after the oven is naturally cooled to room temperature, the grafted thin film is peeled off from the glass substrate, and a polarization process is adopted to obtain the grafted ferroelectric polymer thin film with a high piezoelectric coefficient. The polyvinylidene fluoride-based ferroelectric polymer is modified by grafting side chains, the relative stability of different molecular conformation energies in the ferroelectric polymer is regulated by grafting side chains in the polymer, the ferroelectric phase and the relaxor phase in the ferroelectric polymer are induced to compete with each other, and the piezoelectric coefficient of the material is significantly improved.

A polymer network stabilised liquid crystal material (PN-LCs) having a ferroelectric liquid crystal phase is presented. Claimed is a process of aligning liquid crystal mixtures exhibiting a ferroelectric nematic or ferroelectric smectic A liquid-crystalline phase in a polar vertical state in relation to a boundary surface. The liquid crystal mixture is stabilized by a polymer network in a vertical alignment relative to the substrate planes enclosing the mixtures. In addition, the present invention relates to electric and electronic elements which contain the poled and aligned ferroelectric liquid crystal material according to the invention.

This invention provides a modified ferroelectric polymer composite film, its preparation method, and its applications, belonging to the field of piezoelectric composite material technology. The modified ferroelectric polymer composite film includes a ferroelectric polymer base film and a plurality of composite nanoparticles and multi-walled carbon nanotubes dispersed within the ferroelectric polymer base film. The composite nanoparticles have a core-shell structure, comprising a core and an inner shell layer and an outer shell layer sequentially surrounding the core. The core comprises a composite piezoelectric ceramic material composed of potassium sodium niobate and barium titanate, the inner shell layer comprises polydopamine, and the outer shell layer comprises MnO2. This invention fully utilizes the synergistic effect of the composite nanoparticles and multi-walled carbon nanotubes on the dielectric and piezoelectric properties of P(VDF-TrFE) materials, thereby preparing a composite material with high dielectric constant, low dielectric loss, and excellent piezoelectric properties to meet the stringent performance requirements of high-performance sensors and other application fields.

The invention provides a PVDF-based elastic ferroelectric material and a preparation method and application thereof, and relates to the technical field of ferroelectric materials. A ferroelectric crystal phase region of the PVDF-based elastic ferroelectric material is protected to the maximum extent, and a uniform three-dimensional elastic network structure formed by firm C-C bonds is constructed in an amorphous region by a PVDF-based ferroelectric polymer and a crosslinking sensitizer through radiation crosslinking; the PVDF-based elastic ferroelectric material has excellent ferroelectricity, great flexibility and elasticity, proper strength and excellent fatigue resistance at the same time. According to the preparation method of the PVDF-based elastic ferroelectric material, the technical bottlenecks of thermal crosslinking and photo-crosslinking are fundamentally overcome through a mild, pure and uniform radiation process, so that controllable preparation of the PVDF-based elastic ferroelectric material with excellent ferroelectricity, great flexibility and elasticity, proper strength and excellent fatigue resistance becomes reality; the preparation method is simple, efficient and high in universality, and is very suitable for large-scale industrial production.

The application discloses a ferroelectric material capable of continuously generating recoverable pseudo plastic deformation and a preparation method thereof, and the method comprises the following steps: mixing a ferroelectric polymer and N,N-dimethylformamide (DMF), stirring, pouring on a plate, drying, heat treatment, and obtaining a film; cutting the film into a strip and performing a "programming" process; after the "programming" is completed, a recovery process is performed: firstly, the temperature of the film is raised, and it can be observed that the shape of the film is gradually recovered to the initial shape through rising to different temperatures from a complex shape. The application provides a ferroelectric polymer capable of continuously generating recoverable pseudo plastic deformation under temperature regulation, and the preparation operability is high and the process is relatively simple; the shape of the ferroelectric polymer is regulated in a one-way heating process, and is expected to be applied to some switches which need to be opened in two or N sections or some places which need to release substances step by step.

The application discloses a ferroelectric local field enhanced polarized photoelectric detector and a preparation method thereof, and relates to the technical field of polarized photoelectric detection. The polarized photoelectric detector is observed from bottom to top and sequentially comprises a substrate, a two-dimensional semiconductor layer, a metal electrode pair and a ferroelectric film layer. The material of the two-dimensional semiconductor layer is black phosphorus. The material of the ferroelectric film layer is polyvinyl fluoride-based ferroelectric polymer. The metal electrode pair comprises a first metal electrode and a second metal electrode. A channel structure formed between the first metal electrode and the second metal electrode exposes part of the two-dimensional semiconductor layer. An in-plane PN junction is formed by part of the two-dimensional semiconductor layer exposed after the ferroelectric film layer is electrode polarized. The strong local field of the ferroelectric film changes the Seebeck coefficient and the conductivity of the black phosphorus in the armchair direction and the zigzag direction, enhances the photocurrent in the armchair direction, and greatly improves the polarization detection ratio of the polarized photoelectric detector.

The invention belongs to the field of flexible piezoelectric polymer materials, and discloses a ferroelectric polymer and a method for preparing the ferroelectric polymer through crosslinking modification. The preparation method comprises the following steps: (1) dissolving a polyvinylidene fluoride-based ferroelectric polymer in an organic solvent, adding a cross-linking agent with at least two NH2 groups, uniformly dispersing, then placing the solution in a mold, and drying the solvent to obtain a polymer membrane material; and (2) heating the polymer membrane material to initiate nucleophilic addition reaction-elimination dehydrofluorination reaction for chemical crosslinking to obtain the C = N covalent bond crosslinked polyvinylidene fluoride based ferroelectric polymer membrane material. According to the invention, the polyvinylidene fluoride-based ferroelectric polymer and the diamine cross-linking reagent are subjected to chemical cross-linking, and a local molecular conformation disordered structure is introduced, so that the induced piezoelectric coefficient d33 is remarkably improved.

The invention belongs to the field of semi-solid batteries, and particularly relates to a modified relaxor ferroelectric polymer, a modified semi-solid electrolyte, a preparation method and application of the modified relaxor ferroelectric polymer and the modified semi-solid electrolyte, and a battery. A polymer chain of the polymer modified intermediate is modified with double bonds, and then the polymer modified intermediate and a modifier are polymerized to prepare the modified relaxor ferroelectric polymer; the modifier is represented by formula 1 (). The relaxation polymer is innovatively subjected to dehalogenation treatment and then innovatively subjected to combined polymerization with the formula 1, so that the polymerization behavior and the polymerization structure can be regulated and controlled, the relaxation polymer accidentally adapts to the application requirements of the semi-solid electrolyte, the flowability of the electrolyte can be effectively bound, the electrochemical window of the liquid electrolyte is improved, and the growth of lithium dendrites on the negative electrode side is inhibited; and thus, the high-pressure resistance, the high-temperature resistance stability and the long cycle performance of the semi-solid polymer electrolyte are improved.

The invention belongs to the technical field of cable materials, and relates to a space charge self-elimination type high-voltage direct-current cable shielding material based on molecular dipole field regulation and control and a preparation method and application of the space charge self-elimination type high-voltage direct-current cable shielding material. The shielding material comprises the following raw materials in percentage by weight: 60-65% of base resin, 5-10% of ferroelectric P (VDF-TrFE) nanoparticles, 5-10% of carbon nanotubes, 15-20% of conductive filler and 2-5% of a passivating agent, wherein the sum of the weight percentages of the raw materials is 100%; and the passivating agent is nano cerium dioxide, a magnesium oxide-silicon dioxide core-shell material or a zinc oxide-aluminum oxide core-shell material. The prepared shielding material is used for preparing a high-voltage direct-current cable, the ferroelectric polymer P (VDF-TrFE) in the material is a core carrier for molecular dipole field regulation and control, the conductive filler with high structural degree is in bridge connection with the carbon nanotubes to form a three-dimensional charge dredging path, space charges are eliminated, and the high-voltage resistance of the cable is improved.

The invention relates to a polymer essentially made up of, or consisting of, repeating motifs from vinylidene fluoride (VDF), trifluoroethylene (TrFE), and at least one third monomer different from vinylidene fluoride and trifluoroethylene, the TrFE:VDF molar ratio between the number of moles of motifs from trifluoroethylene and those of motifs from vinylidene fluoride in the polymer being from 14.0:86.0 to 50.0:50.0, said at least one third monomer having a mole fraction xt greater than or equal to 1 ppm and less than or equal to 5000 ppm, relative to the total number of moles of motifs from VDF and TrFE in the polymer.

The application discloses an isolation film, a battery monomer, a battery and a power utilization device. The isolation film comprises a porous base material and a ferroelectric coating layer on at least one surface of the porous base material, wherein the ferroelectric coating layer comprises a ferroelectric material, the ferroelectric material comprises an inorganic ferroelectric and a ferroelectric polymer, the ferroelectric polymer comprises polyvinylidene fluoride and a copolymer thereof, the ferroelectric polymer comprises beta-phase polyvinylidene fluoride, and the content of the beta-phase polyvinylidene fluoride in the ferroelectric polymer is greater than or equal to 60%. The isolation film can slow down the continuous growth of dendrites in the vertical electrode direction, reduce internal short circuit of the battery, improve the reliability of the battery, and also improve the coulomb efficiency and rate performance of the battery.

The invention discloses a quasi-solid aqueous zinc ion battery based on a ferroelectric coating and a sodium alginate gel electrolyte, and relates to the technical field of electrochemical energy storage. The battery comprises a positive electrode, a ferroelectric coating modified zinc negative electrode and a sodium alginate-based gel electrolyte. The ferroelectric coating is formed by compounding a ferroelectric polymer and zinc salt, zinc ion flux is homogenized by utilizing a built-in electric field generated by spontaneous polarization of the ferroelectric coating, zinc is induced to preferentially deposit, dendritic crystal growth is effectively inhibited, and side reactions are reduced; the sodium alginate-based gel electrolyte has a three-dimensional network structure, has high ionic conductivity and excellent mechanical strength, and can physically block dendritic crystal penetration and eliminate the risk of liquid leakage; the synergistic effect of the two significantly improves the cycling stability and safety performance of the battery, solves the problems of easy short circuit and short service life of the aqueous zinc ion battery, and is suitable for the field of high-safety energy storage.

This invention provides a polyvinylidene fluoride-trifluoroethylene ferroelectric copolymer, its preparation method, and its applications, relating to the field of ferroelectric materials technology. The copolymer comprises repeating units derived from vinylidene fluoride and repeating units derived from trifluoroethylene, wherein the molar content of the trifluoroethylene units is 7%–19%; the copolymer has a sequence order defined by parameter S, where S ≥ 90%. This copolymer achieves high Curie temperature and high remanent polarization intensity at low trifluoroethylene content. This invention also provides a method for preparing the polyvinylidene fluoride-trifluoroethylene ferroelectric copolymer, as well as ferroelectric thin films and ferroelectric devices containing this copolymer. This invention overcomes the technical bottleneck of traditional ferroelectric polymers' difficulty in simultaneously achieving high polarization intensity and thermal stability, and can be widely applied in fields such as flexible sensors, non-volatile ferroelectric memories, and energy harvesters.

The application discloses a flexible near-infrared artificial retina device and a preparation method thereof. The flexible near-infrared artificial retina device comprises a flexible substrate, a bottom electrode formed on the flexible substrate, a functional layer comprising an organic ferroelectric polymer film, a rare earth up-conversion nanomaterial and an organic ferroelectric polymer film laminated structure formed on the bottom electrode, and a top transparent electrode formed on the functional layer. The device is excited by near-infrared light, the near-infrared light signal is converted into a reproducible visible light signal by using the anti-Stokes luminescence capability of the rare earth up-conversion nanomaterial, the collection and signal reproduction functions of the near-infrared waveband light information are completed, the processing and memory of the near-infrared information are realized by using the continuously adjustable non-volatile resistance state, and finally the simulation of the artificial retina function is realized.

This invention belongs to the field of flexible piezoelectric polymer materials and discloses a ferroelectric polymer and a method for preparing a ferroelectric polymer by crosslinking modification. The preparation method includes: (1) dissolving polyvinylidene fluoride ferroelectric polymer in an organic solvent, adding a crosslinking agent with at least two NH2 groups, dispersing evenly, then placing the solution in a mold, drying the solvent, and obtaining a polymer film; (2) heating the polymer film to initiate a nucleophilic addition reaction-elimination of defluorination hydrogen reaction for chemical crosslinking, thereby obtaining a polyvinylidene fluoride ferroelectric polymer film crosslinked by C=N covalent bonds. This invention introduces a disordered structure of local molecular conformation by chemically crosslinking polyvinylidene fluoride ferroelectric polymer with a diamine crosslinking agent, thereby inducing a piezoelectric coefficient. d 33 Significant improvement.

The invention relates to the technical field of functional nano materials, in particular to a ferroelectric polymer nanofiber membrane and a preparation method and application thereof.The preparation method comprises the steps that hexamethylene adipamide and formic acid are mixed to obtain a PA solution, and a polyamide electrospun membrane substrate is obtained through electrostatic spinning; the preparation method comprises the following steps: dissolving a ferroelectric polymer in N, N-dimethylacetamide to obtain a ferroelectric polymer solution; dropwise adding the ferroelectric polymer solution to the surface of a polyamide electrospinning membrane substrate, standing, forming a liquid membrane on the surface, adding water, immersing the polyamide electrospinning membrane substrate, carrying out vacuum filtration, and drying to obtain a ferroelectric polymer nanofiber membrane; the ferroelectric polymer comprises polyvinylidene fluoride or a polyvinylidene fluoride derivative. According to the prepared ferroelectric polymer nanofiber membrane, under the condition that the airflow speed is 0.45 m / s, the PM0.3 filtering efficiency is larger than or equal to 99.999%, the resistance is smaller than or equal to 250 Pa, and low air resistance and long-term stability are kept while efficient filtering is achieved.

A separator, a battery cell, a battery, and an electric device are described. The separator comprises a porous base material and a ferroelectric coating located on at least one surface of the porous base material. The ferroelectric coating comprises a ferroelectric material. The ferroelectric material comprises an inorganic ferroelectric and a ferroelectric polymer. The ferroelectric polymer comprises polyvinylidene fluoride and a copolymer thereof, the ferroelectric polymer comprises β-phase polyvinylidene fluoride, and the content of the β-phase polyvinylidene fluoride in the ferroelectric polymer is greater than or equal to 60%. The separator can slow the continuous growth of dendrites in a direction perpendicular to an electrode sheet, reduce internal short circuits of the battery and improve the reliability of the battery, and can further improve the coulombic efficiency and rate performance of the battery.

This invention discloses a quantum dot-modified flexible visual synaptic memristor and its fabrication method. The quantum dot-modified flexible visual synaptic memristor includes: a flexible substrate; a bottom electrode formed on the flexible substrate; a composite functional film composed of perovskite quantum dots and an organic ferroelectric polymer, formed on the bottom electrode; and multiple mutually spaced transparent top electrodes formed on the composite functional film. By applying light source signals and electrical pulse signals to the device, and utilizing the photoelectric response of the perovskite quantum dots and the conductivity modulation function of the ferroelectric polymer, the device simulates the light signal perception, data storage, and computation of an artificial vision system.

The application discloses a preparation method of an organic-inorganic ferroelectric polymer composite film. The method takes a graphene / copper high-index surface with one-dimensional periodic potential as a substrate, uniformly dissolves poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) powder in a tetrahydrofuran organic solvent, adds ground monocrystal lead titanate (PbTiO3) mesoporous material, takes a proper amount of solution after sufficient stirring, spin coats the solution on the substrate, and performs vacuum drying and annealing treatment to obtain the organic-inorganic ferroelectric polymer composite film. The composite film prepared by the method has good orientation and exhibits excellent ferroelectric performance, and has a wide application prospect in flexible transducer devices, sensor devices and ferroelectric memory devices.

The invention discloses a relaxor ferroelectric polymer electrolyte film and a preparation method and application thereof, and belongs to the technical field of solid electrolyte. The method comprises the following steps: mixing an inorganic relaxor ferroelectric material, a polymer, a sodium salt and an organic solvent, heating and stirring to obtain a uniform bubble-free mixed solution; and pouring the mixed solution into a mold for shaping, and drying to obtain the relaxor ferroelectric polymer electrolyte film. The electrolyte film has high ionic conductivity, high ionic transference number and high mechanical property. The sodium metal battery prepared from the electrolyte film has excellent electrochemical performance.

This invention discloses a method for preparing a single-matrix full-spectrum luminescent polyvinylidene fluoride (PVDF) ferroelectric thin film based on controlled segment rearrangement. The method involves dissolving PVDF ferroelectric polymer powder in an organic solvent to obtain a transparent solution; dividing the transparent solution into at least three portions, one without the addition of an alkaline reagent, and adding different amounts of alkaline reagent to the remaining portions to obtain at least three reaction solutions; adding each of the at least three reaction solutions to an aqueous phase to obtain PVDF solids without conjugation and at least two PVDF solids with different degrees of conjugation; mixing the PVDF solids and redissolving and stirring to form a transparent solution; and dripping the transparent solution onto a substrate and subjecting it to heat treatment to prepare the PVDF ferroelectric thin film. The preparation method provided by this invention constructs a main-chain conjugated structure through a controlled segment rearrangement reaction and combines it with a segment synergistic construction strategy to simultaneously maintain broad-spectrum luminescence and ferroelectric properties.