阅读说明：本技术 银/铌钽酸钾/钛酸钡复合聚合物介电材料的制备方法 (preparation method of silver/potassium tantalate niobate/barium titanate composite polymer dielectric material ) 是由 张启龙 张钊 杨辉 于 2019-10-13 设计创作，主要内容包括：本发明涉及纳米复合材料技术领域,旨在提供一种银/铌钽酸钾/钛酸钡复合聚合物介电材料的制备方法。包括：将聚偏氟乙烯-三氟乙烯-三氟氯乙烯加入N,N-二甲基甲酰胺中,室温下混合、搅拌至澄清；以负载有银的铌钽酸钾/钛酸钡复合粉体作为填充物,将其分散在澄清溶液中,得到均匀的悬浊液；将悬浊液经滴涂成型,经干燥、保温后进行骤冷处理,得到薄膜状的复合聚合物介电材料。本发明构建的复合介电材料可增加无机颗粒间、无机颗粒/聚合物界面相互作用区域,实现界面极化效应增强,提高复合材料的介电常数,降低介电损耗。本发明制备工艺简单,方法的可操作性和可重复性高,可应用于储能电容器、柔性电子器件等制造,具有广阔的应用前景。(The invention relates to the technical field of nano composite materials, and aims to provide a preparation method of a silver/potassium tantalate niobate/barium titanate composite polymer dielectric material. The method comprises the following steps: adding polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene into N, N-dimethylformamide, mixing and stirring at room temperature until the mixture is clear; dispersing the silver-loaded potassium niobate tantalate/barium titanate composite powder serving as a filler in a clear solution to obtain a uniform suspension; and (4) drop-coating and forming the suspension, drying, preserving heat and then carrying out quenching treatment to obtain the film-shaped composite polymer dielectric material. The composite dielectric material constructed by the invention can increase interaction areas among inorganic particles and between inorganic particle/polymer interfaces, realize the enhancement of the interface polarization effect, improve the dielectric constant of the composite material and reduce the dielectric loss. The preparation method is simple in preparation process, high in operability and repeatability, capable of being applied to manufacturing of energy storage capacitors, flexible electronic devices and the like, and wide in application prospect.)

1. A preparation method of a silver/potassium tantalate niobate/barium titanate composite polymer dielectric material is characterized by comprising the following steps:

(1) Adding polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene into N, N-dimethylformamide according to the volume ratio of 1: 80, mixing at room temperature, and stirring until the mixture is clear; dispersing the silver-loaded potassium niobate tantalate/barium titanate composite powder serving as a filler in a clear solution to obtain a uniform suspension;

(2) Forming the suspension by drop coating, drying in a vacuum oven at 60 ℃ for 24 hours, and continuing to perform vacuum heat preservation at 150-170 ℃ for 10 minutes; taking out, placing in ice water for quenching treatment to obtain a film-shaped composite polymer dielectric material;

In the step (1), the mol ratio of silver, potassium tantalate niobate and barium titanate in the filler is 3: 25; the amount of the filler is controlled to be 5 to 20% of the total volume of the composite polymer dielectric material in the form of a film.

2. the method according to claim 1, wherein the dispersing in step (1) is: after 1h of ultrasonic dispersion, the mixture was stirred at room temperature for 5h, and this operation was repeated once.

3. The method according to claim 1, wherein the polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene in the step (1) is a terpolymer, and the molar ratios of the three components are respectively as follows: 64.2 mol% of polyvinylidene fluoride, 27.1 mol% of polytrifluoroethylene and 8.7 mol% of polytrifluorochloroethylene.

4. A method according to any one of claims 1 to 3, characterized in that the filling is obtained by a method comprising:

(1) Dissolving 28g of potassium hydroxide in 50ml of deionized water in a stainless steel reaction kettle with a polytetrafluoroethylene inner container, and stirring at room temperature until the solution is clear; taking powdery niobium pentoxide, tantalum pentoxide and barium titanate according to the mol ratio of 1: 4: 10, dispersing the powdery niobium pentoxide, tantalum pentoxide and barium titanate in a clear solution, and reacting at 180-200 ℃ for 22-26 h; the mass ratio of the potassium hydroxide to the niobium pentoxide is 28: 1.06;

(2) After the reaction is finished, naturally cooling to room temperature; centrifuging the solid product and washing with deionized water until the pH approaches 7; then drying for 24 hours at 60 ℃ to obtain potassium niobate tantalate/barium titanate composite powder;

(3) dispersing the potassium niobate tantalate/barium titanate composite powder in deionized water according to the ratio of 0.2g of composite powder to 50ml of deionized water, then adding 0.1g of AgNO ₃ particles, stirring for 1h at normal temperature in the dark place, placing the mixed solution under a 300W xenon lamp for irradiation reaction for 90-180 min, sequentially washing the powder by using deionized water and ethanol in a centrifugal mode, and drying for 12h at 60 ℃ to obtain the silver-loaded potassium niobate tantalate/barium titanate composite powder.

Technical Field

The invention belongs to the technical field of nano composite materials, and particularly relates to a silver/potassium tantalate niobate/barium titanate composite polymer dielectric material and a preparation method thereof.

Background

With the rapid development of sustainable energy production technology and electronic technology, energy storage capacitors have a wide application in the fields of energy storage devices and electronic devices due to their high dielectric constant, large energy storage density and the possibility of being embedded in the plates of integrated circuits. Dielectric materials are used as a very critical part of energy storage capacitors and play an important role in their performance.

The conventional dielectric materials mainly comprise two main types, namely ceramics and polymers, and the problems exist at present, the ceramics such as barium titanate (BaTiO ₃) and the like have high dielectric constant and polarization strength, but the breakdown strength is very low, the weight is heavy, the processability is poor and the like, so that the ceramics cannot meet the current requirements on the dielectric materials, and the polymers have high breakdown strength, light weight, good processability and the like, but the dielectric constant of most polymers is low (<10), so that the dielectric materials which have good dielectric property and excellent flexibility are prepared and are the key for improving the energy storage capacitor.

The polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene is a terpolymer of the polyvinylidene fluoride, has higher dielectric constant (Tg & gt 30), good flexibility, is easy to form and is suitable for large-scale production. However, the dielectric properties such as dielectric constant are still insufficient, and the application of the material in the fields of energy storage capacitors, flexible electronic devices and the like is limited.

Disclosure of Invention

The invention aims to solve the problem of overcoming the defects in the prior art and provides a preparation method of a silver/potassium tantalate niobate/barium titanate composite polymer dielectric material with a high dielectric constant and low dielectric loss.

In order to solve the technical problem, the technical scheme adopted by the invention is as follows:

the preparation method of the silver/potassium tantalate niobate/barium titanate composite polymer dielectric material comprises the following steps:

(1) Adding polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene into N, N-dimethylformamide according to the volume ratio of 1: 80, mixing at room temperature, and stirring until the mixture is clear; dispersing the silver-loaded potassium niobate tantalate/barium titanate composite powder serving as a filler in a clear solution to obtain a uniform suspension;

(2) Forming the suspension by drop coating, drying in a vacuum oven at 60 ℃ for 24 hours, and continuing to perform vacuum heat preservation at 150-170 ℃ for 10 minutes; taking out, placing in ice water for quenching treatment to obtain a film-shaped composite polymer dielectric material;

In the step (1), the mol ratio of silver, potassium tantalate niobate and barium titanate in the filler is 3: 25; the amount of the filler is controlled to be 5 to 20% of the total volume of the composite polymer dielectric material in the form of a film.

In the present invention, the dispersion in the step (1) means: after 1h of ultrasonic dispersion, the mixture was stirred at room temperature for 5h, and this operation was repeated once.

In the invention, the polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene in the step (1) is a terpolymer, and the molar ratios of the three components are respectively as follows: 64.2 mol% of polyvinylidene fluoride, 27.1 mol% of polytrifluoroethylene and 8.7 mol% of polytrifluorochloroethylene.

in the invention, the filler is prepared by the following method:

(1) Dissolving 28g of potassium hydroxide in 50ml of deionized water in a stainless steel reaction kettle with a polytetrafluoroethylene inner container, and stirring at room temperature until the solution is clear; taking powdery niobium pentoxide, tantalum pentoxide and barium titanate according to the mol ratio of 1: 4: 10, dispersing the powdery niobium pentoxide, tantalum pentoxide and barium titanate in a clear solution, and reacting at 180-200 ℃ for 22-26 h; the mass ratio of the potassium hydroxide to the niobium pentoxide is 28: 1.06;

(2) After the reaction is finished, naturally cooling to room temperature; centrifuging the solid product and washing with deionized water until the pH approaches 7; then drying for 24 hours at 60 ℃ to obtain potassium niobate tantalate/barium titanate composite powder;

(3) Dispersing the potassium niobate tantalate/barium titanate composite powder in deionized water according to the ratio of 0.2g of composite powder to 50ml of deionized water, then adding 0.1g of AgNO ₃ particles, stirring for 1h at normal temperature in the dark place, placing the mixed solution under a 300W xenon lamp for irradiation reaction for 90-180 min, sequentially washing the powder by using deionized water and ethanol in a centrifugal mode, and drying for 12h at 60 ℃ to obtain the silver-loaded potassium niobate tantalate/barium titanate composite powder.

Description of the inventive principles:

Compared with the prior art, the silver/potassium tantalate niobate/barium titanate composite powder has the advantages that the silver/potassium tantalate niobate/barium titanate composite powder does not have great pollution to the environment caused by lead, the Curie temperature is higher, the interaction of interfaces among inorganic particles can be increased, the interface polarization effect is enhanced, the dielectric constant of the composite material is improved, and simultaneously the coulomb blockage effect and the quantum size effect of silver nanoparticles can reduce the dielectric loss. And the prior art mainly considers introducing the inorganic filler with high dielectric constant rather than improving the dielectric property of a polymer substrate when improving the dielectric property of the composite material, so the invention also replaces the traditional polymer with polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene (PVDF terpolymer) which has higher dielectric constant, flexibility and easy molding compared with PVDF from the aspect of improving the polymer. Therefore, the silver/potassium tantalate niobate/polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene composite dielectric material has wide application prospect, and has no pollution, high Curie temperature and high dielectric property.

Compared with the prior art, the invention has the advantages that:

1. The potassium niobate tantalate/barium titanate composite powder with uniform appearance and size is prepared by a hydrothermal method, nitrate is reduced by illumination, and nano silver particles are loaded on the surface of the nitrate. The silver-loaded potassium niobate tantalate/barium titanate composite polymer dielectric film is prepared by solution blending and drop coating molding. The composite dielectric material constructed can increase interaction areas between inorganic particles and between inorganic particle/polymer interfaces, realize the enhancement of interface polarization effect, improve the dielectric constant of the composite material, and simultaneously reduce the dielectric loss by the coulomb blockage effect and the quantum size effect of the silver nanoparticles.

2. The preparation method is simple in preparation process, high in operability and repeatability, capable of being applied to manufacturing of energy storage capacitors, flexible electronic devices and the like, and wide in application prospect.

Drawings

FIG. 1 is an electron micrograph of silver/potassium tantalate niobate/barium titanate.

Wherein, the picture (a) is a Transmission Electron Microscope (TEM) picture of silver/potassium tantalate niobate/barium titanate prepared in the examples, and the picture (b) is a High Resolution Transmission Electron Microscope (HRTEM) picture of silver/potassium tantalate niobate/barium titanate.

FIG. 2 is an XRD spectrum of potassium tantalate niobate/barium titanate and silver-loaded potassium tantalate/barium titanate.

Detailed Description

The present invention is further described below with reference to examples and comparative examples, which allow a person skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

In the present invention, the preparation method of polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene (terpolymer, abbreviated as P (VDF-TrFE-CTFE)) is the prior art, and the preparation can be realized by those skilled in the art according to the mastery skill thereof, so that the detailed description thereof is omitted. In the following examples of the present invention, the terpolymer employs three components in molar ratios, respectively: the preferable embodiment is 64.2 mol% of polyvinylidene fluoride, 27.1 mol% of polytrifluoroethylene and 8.7 mol% of polytrifluorochloroethylene. Of course, the purpose of the invention can be achieved by adopting the components in other proportioning relations, and only the product performance of the final product is slightly different.

The addition amount of the filler (silver-loaded potassium tantalate niobate/barium titanate composite powder) is controlled to be 5-20% of the total volume of the film composite dielectric material. The volume fraction rather than the mass fraction is mainly used because the dispersibility of the inorganic particles in the polymer is an important factor influencing the performance of the composite dielectric material, and the volume fraction rather than the mass fraction can be used to reflect the space occupied by the inorganic particles in the composite material.