CN115594928A - Piezoelectric polymer-based foam with oriented pore structure and preparation method thereof - Google Patents
Piezoelectric polymer-based foam with oriented pore structure and preparation method thereof Download PDFInfo
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- 229920000642 polymer Polymers 0.000 title claims abstract description 48
- 239000011148 porous material Substances 0.000 title claims abstract description 34
- 239000006260 foam Substances 0.000 title claims abstract description 27
- 238000002360 preparation method Methods 0.000 title abstract description 31
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims abstract description 75
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- 238000007710 freezing Methods 0.000 claims abstract description 30
- 230000008014 freezing Effects 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 26
- 239000000919 ceramic Substances 0.000 claims abstract description 11
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- 239000002798 polar solvent Substances 0.000 claims abstract description 9
- 238000002156 mixing Methods 0.000 claims abstract description 3
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- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 69
- 239000008187 granular material Substances 0.000 claims description 30
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 claims description 26
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 22
- 239000011259 mixed solution Substances 0.000 claims description 18
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- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 9
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 8
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 6
- 229910002113 barium titanate Inorganic materials 0.000 claims description 6
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 6
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 claims description 6
- 229910052451 lead zirconate titanate Inorganic materials 0.000 claims description 6
- 239000008188 pellet Substances 0.000 claims description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 4
- 235000011089 carbon dioxide Nutrition 0.000 claims description 4
- 239000002041 carbon nanotube Substances 0.000 claims description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 4
- 239000002608 ionic liquid Substances 0.000 claims description 4
- UKDIAJWKFXFVFG-UHFFFAOYSA-N potassium;oxido(dioxo)niobium Chemical compound [K+].[O-][Nb](=O)=O UKDIAJWKFXFVFG-UHFFFAOYSA-N 0.000 claims description 4
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- 150000002500 ions Chemical class 0.000 description 2
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- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/0061—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof characterized by the use of several polymeric components
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/0066—Use of inorganic compounding ingredients
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/0066—Use of inorganic compounding ingredients
- C08J9/0071—Nanosized fillers, i.e. having at least one dimension below 100 nanometers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2201/00—Foams characterised by the foaming process
- C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
- C08J2201/048—Elimination of a frozen liquid phase
- C08J2201/0482—Elimination of a frozen liquid phase the liquid phase being organic
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08J2327/16—Homopolymers or copolymers of vinylidene fluoride
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2427/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2427/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2427/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08J2427/16—Homopolymers or copolymers of vinylidene fluoride
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- Polymers & Plastics (AREA)
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Abstract
The invention discloses a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, uniformly mixing piezoelectric polymer, piezoelectric ceramic and a modifier with a solvent DMSO, carrying out directional freezing, and placing a sample in a strong polar solvent for solvent exchange to prepare the piezoelectric polymer-based foam with an oriented pore structure. The method combines the directional freezing and the solvent exchange to realize the piezoelectric polymer-based foam with the oriented pore structure, which is difficult to obtain by the conventional freeze drying method, and improve the piezoelectric sensing performance and the mechanical-electrical conversion efficiency of the piezoelectric material. The product prepared by the method of the invention is used for developing intelligent electronic devices such as electronic skin, implantable wearable equipment, flexible stress sensors and the like for acquiring human physiological signals and collecting mechanical energy, and is used in the fields of human detection, intelligent sensing and the like.
Description
Technical Field
The invention belongs to the technical field of modification of piezoelectric polymer materials, and particularly relates to piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof.
Background
In recent years, flexible stress sensors have shown great potential in the fields of human body dynamic detection, human-computer interaction, health monitoring and the like. Based on the piezoelectric sensor that converts mechanical energy into electrical energy, the piezoelectric sensor has gained wide attention and application due to its advantages such as high frequency detection, fast response and self-power supply. PVDF and its copolymers are currently the most commonly used piezoelectric polymers. The fluorine-containing polymer is stable at room temperature, and has good flexibility, chemical inertness, biocompatibility and outstanding piezoelectric conversion efficiency.
The properties of PVDF and its copolymers are directly influenced by its structure, mainly depending on its crystalline form. Taking PVDF as an example, five crystal forms of PVDF exist, the most common of which are the α and β phases, with the F and H atoms of α -PVDF alternately arranged on both sides, with dipole moments in opposite directions, and no piezoelectric properties. The dipole moment of the beta-PVDF is in the same direction and vertical to the main chain, the F atom is concentrated on one side of the carbon chain, and the beta-PVDF is the crystal form with the best piezoelectric property. However, the conformation of the alpha phase is thermodynamically stable. Therefore, increasing the beta phase content is a key issue in developing PVDF as a piezoelectric device application. Currently, many research methods can achieve the improvement of the beta phase content in PVDF by inducing the arrangement of dipoles, such as high electric field polarization, electric stretching, and adding nucleating agents. In addition, the excellent piezoelectric property of the inorganic piezoelectric ceramic is utilized to overcome the defects of hardness and fragility of the piezoelectric ceramic, and the inorganic piezoelectric ceramic is dispersed in the piezoelectric polymer matrix as a filler, so that the piezoelectric output property of PVDF and copolymers thereof can be further improved.
On the other hand, the three-dimensional structure is constructed on the microstructures of PVDF and the copolymers thereof by utilizing the mechanisms of stress concentration effect, nano confinement effect and the like, so that the three-dimensional structure is an effective way for improving the force-electricity conversion and sensing performances. Although PVDF and its copolymer materials have been much explored in structural design, such as pyramid arrays, thin-walled structures, and interlocking structures. However, most of the materials are still isotropic at present, which limits the application of such materials in the field of piezoelectric sensing. The directional freezing mode is an ideal mode for constructing an oriented pore structure. It is a process in which ice crystals growing directionally along a temperature gradient act as an induced template to replicate their oriented structure. However, since the polar solvent for dissolving the piezoelectric polymer is generally a low freezing point (e.g., N dimethylformamide at-61 ℃), a low vapor pressure (e.g., dimethylsulfoxide). Freeze-drying at very low temperatures not only places severe demands on the equipment, but also results in high energy consumption. The low vapor pressure solvent is less volatile during the freeze-drying process and is prone to change to a liquid state, resulting in collapse of the oriented pores. Thus, conventional directional freezing methods are not currently well-established for use with PVDF and its copolymers. This challenge also makes the construction of anisotropic piezoelectric polymers challenging.
Disclosure of Invention
The invention aims to: aiming at the defects in the prior art, the piezoelectric polymer-based foam with the oriented pore structure and the preparation method thereof are provided, and the piezoelectric polymer-based foam has the advantages of high electroactive crystal, flexibility, high piezoelectric sensitivity, anisotropic sensing and the like, and the preparation method provides a new thought for the development of piezoelectric devices and promotes the development of piezoelectric polymer anisotropic piezoelectric functional devices.
The technical scheme adopted by the invention is as follows:
a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof are characterized by comprising the following steps:
a. uniformly mixing a piezoelectric polymer, piezoelectric ceramics, a modifier and a solvent to form a mixed solution;
b. placing the mixed solution in a mould, and directionally freezing;
c. and (3) placing the molded sample in a strong polar solvent for solvent exchange, and drying to obtain the product.
It is worth to explain that, the invention selects the solvent with high vapor pressure and low freezing point to realize the directional freezing of the piezoelectric polymer dissolved in the organic solvent; the characteristic that PVDF and the copolymer thereof are subjected to phase separation in a strong polar solvent is utilized, the process of solvent exchange is introduced, the oriented pore arrangement form given by oriented freezing is reserved, and the oriented pore structure which is difficult to obtain by the conventional freezing mode of the conventional piezoelectric polymer is obtained; on the other hand, the hole structure expands the design of the piezoelectric polymer structure and improves the piezoelectric output and sensing performance of the piezoelectric polymer.
Typically, the piezoelectric polymer pellets of step (a) are selected from one or a combination of PVDF pellets, PVDF-TrFE pellets.
Typically, the solvent of step a is selected from dimethylsulfoxide.
Typically, the piezoelectric ceramic of step (a) is selected from one or a combination of two or more of barium titanate, lead zirconate titanate, zinc oxide and potassium niobate.
Typically, the modifier of step (a) is selected from one or a combination of two of ionic liquid, carbon nanotube, graphene and two-dimensional titanium carbide.
The modifier utilizes the strong ion-dipole, dipole-dipole and hydrogen bond interaction between ions, hydroxyl, fluorine atoms and the-CH bond and-CF bond of PVDF, so that the high beta crystal content of PVDF can be effectively induced, and the piezoelectric polymer functional device with high beta crystal content can be obtained.
Generally, the strongly polar solvent in step (c) is one or a mixture of more than two of water, methanol, ethanol, isopropanol, methyl ethyl ketone, acetone and ethyl acetate, the solvent exchange temperature is less than 10 ℃, and the solvent exchange time is 16-48h.
Further, the mass ratio of the piezoelectric ceramic to the piezoelectric polymer is 0-2.
Further, the mass ratio of the modifier to the piezoelectric polymer is 0 to 1.5.
Further, the mold filled with the mixed solution is placed on a copper plate, liquid nitrogen or ethanol added with dry ice is used as a cold source at the bottom, and the directional freezing is carried out for 30s-20min.
Further, the piezoelectric polymer/piezoelectric ceramic/modifier composite is soaked in a strong polar solvent at 0-10 ℃ for exchange.
Further, the sample is placed in a strong polar solvent for exchange time of 16-48h.
Further, the sample drying mode comprises drying at room temperature of 25 ℃ for 24-48h, drying in an oven at 25-30 ℃ for 24-48h or freeze drying at-45 ℃ and-5 Pa for 24-48h, thus obtaining the product.
The piezoelectric polymer-based foam with the oriented pore structure is prepared by the method.
The use of the above-described piezoelectric polymer-based foam with an oriented pore structure for the preparation of piezoelectric devices, including energy collectors, sensors, wearable devices, and the like.
In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:
1. the method combines the directional freezing and the solvent exchange mode, constructs an oriented pore structure which is difficult to obtain by the conventional freezing, has the characteristics of structure and sensing anisotropy, and expands the structural design and application of PVDF and the copolymer thereof;
2. according to the invention, strong ion-dipole, dipole-dipole and hydrogen bond interaction exists between ions and polar groups contained in the modifier and-CH and-CF bonds of PVDF, so that the high beta crystal content of PVDF can be effectively induced, a piezoelectric polymer functional device with high beta crystal content (beta crystal content is 95%) is obtained, and the piezoelectric performance is greatly improved;
3. the PVDF and the PVDF copolymer serving as raw materials used in the invention are used as general commercial plastics and have excellent physical and chemical properties;
4. the piezoelectric polymer-based foam with the oriented pore structure can be used as a piezoelectric mechanical energy collecting device, a piezoelectric sensor, a piezoelectric driver and the like, and is used in the fields of new energy, pressure sensing, artificial intelligence and the like.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is an infrared test of pure PVDF, PVDF with two-dimensional titanium carbide added;
FIG. 2 is a DSC test of pure PVDF, PVDF with two-dimensional titanium carbide added;
FIG. 3 is an SEM image of a cross-sectional view of PVDF with two-dimensional titanium carbide added;
FIG. 4 is an SEM image of a longitudinal sectional view of PVDF with two-dimensional titanium carbide added;
FIG. 5 is a compression test of PVDF samples with two-dimensional titanium carbide addition in different directions;
FIG. 6 shows the current output test in different directions for PVDF piezoelectric devices with two-dimensional titanium carbide;
fig. 7 shows the current output test in different directions of the PVDF piezoelectric device with two-dimensional titanium carbide added.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
It is noted that relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of other like elements in a process, method, article, or device comprising the element.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 1.5g of PVDF granules in 10ml of dimethyl sulfoxide (DMSO) solvent, keeping the temperature at 65 ℃, rotating speed at 500rpm, and stirring for 3.5h until the PVDF granules are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a mold of 2cm × 2cm × 5mm, placing the mold filled with the solution on a copper plate, taking liquid nitrogen as a cold source at the lower part, and directionally freezing for 15min; and (3) placing the molded sample in water at 4 ℃ for solvent exchange for 48h, and freeze-drying at-45 ℃ and-5 Pa for 24h to obtain the product.
Example 2
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 1.5g of PVDF granules in 10ml of dimethyl sulfoxide (DMSO) solvent, keeping the temperature at 65 ℃, rotating speed at 500rpm, and stirring for 3.5h until the PVDF granules are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, adding ethanol with dry ice as cold source, and directionally freezing for 10min; and (3) placing the molded sample in a mixed solution of water and ethanol at the temperature of 5 ℃ for 16h of solvent exchange, and drying at the room temperature of 25 ℃ for 48h to obtain the product.
Example 3
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.225g of two-dimensional titanium carbide in 10ml of dimethyl sulfoxide (DMSO) solvent, then pouring 1.275g of PVDF granules, keeping the temperature at 65 ℃, rotating speed at 500rpm, and stirring for 3.5h until the PVDF granules and the two-dimensional titanium carbide are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, taking liquid nitrogen as a cold source below the mold, and directionally freezing for 15min; and (3) placing the molded sample in water at 9 ℃ for solvent exchange for 48h, and then freeze-drying for 24h at-45 ℃ and-5 Pa to obtain the product.
Example 4
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, 0.1125g of carbon nano tubes are uniformly dispersed in 10ml of dimethyl sulfoxide (DMSO), then 1g of PVDF granules and 0.3875g of PVDF-TrFE granules are poured into the mixture, the stirring table is kept at 500rpm, the temperature is 65 ℃, and the mixture is stirred for 3.5 hours until the PVDF granules, the PVDF-TrFE granules and the carbon nano tubes are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, taking liquid nitrogen as a cold source below the mold, and directionally freezing for 30s; and (3) placing the molded sample in isopropanol at 0 ℃ for solvent exchange for 34h, and drying in an oven at 30 ℃ for 36h to obtain the product.
Example 5
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.135g of two-dimensional titanium carbide in 10ml of dimethyl sulfoxide (DMSO), then pouring 1.365g of PVDF-TrFE granules, keeping the rotating speed of 500rpm on a stirring table, stirring at 65 ℃ for 3.5 hours until the PVDF-TrFE granules and the two-dimensional titanium carbide are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, using liquid nitrogen as a cold source below the mold, and directionally freezing for 10min; and (3) placing the formed sample in ethyl acetate at 5 ℃ for solvent exchange for 16h, and drying in an oven at 30 ℃ for 48h to obtain the material.
Example 6
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.3g of barium titanate in 10ml of dimethyl sulfoxide (DMSO), then pouring 1.2g of PVDF-TrFE granules, keeping the rotating speed of 500rpm on a stirring table, stirring at 65 ℃ for 3.5h until the PVDF-TrFE granules and the barium titanate are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, using liquid nitrogen as a cold source below the mold, and directionally freezing for 20min; and (3) placing the formed sample in methyl ethyl ketone at 0 ℃ for solvent exchange for 24 hours, and drying in an oven at 30 ℃ for 24 hours to obtain the product.
Example 7
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.15g of potassium niobate and 0.225g of ionic liquid in 10ml of dimethyl sulfoxide (DMSO), then pouring 1.125g of PVDF granules, keeping the rotating speed of 500rpm on a stirring table, stirring at 65 ℃ for 3.5h until the PVDF granules, the potassium niobate and the ionic liquid are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, using liquid nitrogen as a cold source below the mold, and directionally freezing for 10min; and (3) placing the molded sample in acetone at 0 ℃ for 18h of solvent exchange, and drying at room temperature of 25 ℃ for 36h to obtain the product.
Example 8
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.25g of lead zirconate titanate and 0.1g of two-dimensional titanium carbide in 10ml of dimethyl sulfoxide (DMSO), then pouring 1g of PVDF granules and 0.25g of PVDF-TrFE granules, and stirring for 3.5 hours at a stirring table at a rotating speed of 500rpm and a temperature of 65 ℃ until the PVDF granules, the PVDF-TrFE, the lead zirconate titanate and the two-dimensional titanium carbide are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold containing the solution on a copper plate, taking liquid nitrogen as a cold source at the lower part, and directionally freezing for 10min; and (3) placing the formed sample in water for 24h of solvent exchange, and drying at room temperature of 25 ℃ for 24h to obtain the product.
Example 9
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.2g of zinc oxide and 0.05g of graphene in 10ml of dimethyl sulfoxide (DMSO), then pouring 1g of PVDF granules and 0.25g of PVDF-TrFE granules, keeping the rotating speed of 500rpm on a stirring table, stirring at 65 ℃ for 3.5h until the PVDF granules, the PVDF-TrFE granules, the zinc oxide and the graphene are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold containing the solution on a copper plate, taking liquid nitrogen as a cold source at the lower part, and directionally freezing for 10min; and (3) placing the formed sample in a mixed solution of water and methanol at 0 ℃ for solvent exchange for 24 hours, and drying in an oven at 30 ℃ for 36 hours to obtain the nano-composite material.
Example 10
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.3g of barium titanate and 0.05g of graphene in 10ml of dimethyl sulfoxide (DMSO), then pouring 1g of PVDF granules and 0.15g of PVDF-TrFE granules, keeping the rotating speed of 500rpm on a stirring table, stirring at 65 ℃ for 3.5h until the PVDF granules, the PVDF-TrFE granules, the barium titanate and the graphene are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold containing the solution on a copper plate, taking liquid nitrogen as a cold source at the lower part, and directionally freezing for 10min; and (3) placing the molded sample in water for solvent exchange for 48 hours, and then freeze-drying for 36 hours at-45 ℃ and-5 Pa.
Example 11
The preferred embodiment of the invention provides a piezoelectric polymer-based foam with an oriented pore structure and a preparation method thereof, and the preparation method comprises the following specific steps:
firstly, uniformly dispersing 0.4g of lead zirconate titanate and 0.1g of graphene in 10ml of dimethyl sulfoxide (DMSO), then pouring 1g of PVDF granules, and stirring at 65 ℃ for 3.5h in a stirring table at a rotating speed of 500rpm until the PVDF granules, the lead zirconate titanate and the graphene are completely dissolved and dispersed in the DMSO solvent; placing the mixed solution into a 2cm × 2cm × 5mm mold, placing the mold filled with the solution on a copper plate, adding ethanol with dry ice as cold source, and directionally freezing for 10min; and (3) placing the formed sample in water for solvent exchange for 48 hours, and then freeze-drying for 48 hours at-45 ℃ and-5 Pa to obtain the product.
Experimental example 1
The pure PVDF of example 1 and the PVDF of example 3 with the addition of two-dimensional titanium carbide were subjected to crystal form and morphology characterization: the crystal structure of PVDF (Nicolet is50, thermo Fisher, USA) was identified by infrared spectroscopy (FT-IR) with a resolution of 4cm -1 4000-400cm analyzed by ATR mode -1 Representative bands within the range and quantitatively calculating phase content; performing thermal analysis by Differential Scanning Calorimetry (DSC), and measuring the melting point (Tm) and the crystallinity (χ c) (the mass of the sample is about 7mg, the temperature range is 30-200 ℃, the heating rate is 10 ℃/min, and the sample is in a nitrogen atmosphere); the morphologies of the cross section and the longitudinal section of the sample were characterized by scanning electron microscopy (Quanta 250, FEI, japan); the samples were tested for compressibility perpendicular to the bore direction and parallel to the bore direction using a Bose compressor (DWD-100, china), respectively.
FTIR results show that after the two-dimensional titanium carbide is introduced, the beta phase content of pure PVDF without the modifier is 41%, and the beta phase content of PVDF after the two-dimensional titanium carbide is modified can reach 95%, which proves that the two-dimensional titanium carbide can realize high beta crystal content of PVDF. DSC results show that the melting point is reduced and the melting peak is widened when the two-dimensional titanium carbide is added, which shows that the interaction of the two-dimensional titanium carbide and PVDF induces the transformation of PVDF crystal form; DSC calculation results show that the crystallinity χ c of pure PVDF is 68.6 percent, and when the content of the two-dimensional titanium carbide is 9 weight percent, the crystallinity χ c is about 85.4 percent and is improved by about 16.8 percent; the SEM images of the formed samples show that the shapes of the cross sections and the longitudinal sections of the samples are greatly different, the cross sections are of cellular porous structures which are regularly distributed, and the longitudinal sections are of duct structures which are parallel to the freezing direction, so that the piezoelectric polymer-based foam with the oriented pore structures is successfully prepared by combining the oriented freezing and solvent exchange methods.
Experimental example 2
The two-dimensional titanium carbide modified PVDF of example 3 was subjected to compression testing in the direction perpendicular to the pore and in the direction parallel to the pore, and the results are shown in fig. 5, where the compression curves in the two directions are clearly different and the two directions are deformed more in the direction perpendicular to the pore with the same compression strength. It follows that the structural differences of the articles obtained by directional freezing and solvent exchange affect the compression properties.
Experimental example 3
Characterization of the piezoelectric Properties
Piezoelectric performance testing was performed using a linear motor and Labview system, i.e., the two-dimensional titanium carbide modification of example 3 and the oriented frozen and solvent exchanged PVDF part was attached to an electrode, to which a force was applied by the linear motor, and a charge was introduced into an electrometer (Keithley 6514) via a wire connection and converted into a visible electrical signal.
The result is shown in fig. 7, the current output of the two-dimensional titanium carbide modified PVDF shows a trend of increasing with the increase of the external force under different external force impacts; meanwhile, the current output of the device is larger because the external force applied to the direction perpendicular to the hole generates larger deformation than that parallel to the hole, which proves the anisotropy of the sensing of the device.
Experimental example 4
The piezoelectric sensing performance of the PVDF-based piezoelectric device of the document was compared to that of the piezoelectric polymer-based foam having an oriented pore structure prepared in example 3 of the present invention, and the results are shown in table 1 below:
table 1 comparison table of piezoelectric conversion performance of modified DIW piezoelectric device of the present invention with literature
PVDF/GP, PVDF/rGO and PVDF/h-BN are respectively graphene, reduced graphene oxide and hexagonal boron nitride are used as products of a beta crystal inducer and a PVDF matrix, and PVDF/two-dimensional titanium carbide is the PVDF modified by the two-dimensional transition metal carbide of the invention
The above description is intended to be illustrative of the preferred embodiment of the present invention and should not be taken as limiting the invention, but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
Claims (10)
1. A method of making a piezoelectric polymer-based foam having an oriented pore structure, comprising the steps of:
a. uniformly mixing the piezoelectric polymer granules with piezoelectric ceramics, a modifier and a solvent to form a mixed solution;
b. placing the mixed solution in a mould, and performing directional freezing;
c. and (3) placing the formed sample in a strong polar solvent for solvent exchange, and drying to obtain the product.
2. The method of claim 1, wherein the piezoelectric polymer pellets of step (a) are selected from one or a combination of PVDF pellets, PVDF-TrFE pellets.
3. The method according to claim 1, wherein the piezoelectric ceramic of step (a) is selected from one or more of barium titanate, lead zirconate titanate, zinc oxide, and potassium niobate.
4. The method of claim 1, wherein the modifier in step (a) is selected from one or a combination of two or more of ionic liquid, carbon nanotube, graphene and two-dimensional titanium carbide.
5. The method of claim 1, wherein the solvent of step (a) is dimethyl sulfoxide.
6. The method according to claim 1, wherein the mass ratio of the piezoelectric ceramic to the piezoelectric polymer is 0-2.
7. The method of claim 1, wherein the freezing fluid in step (b) is liquid nitrogen or ethanol added with dry ice, and the directional freezing is performed.
8. The method according to claim 1, wherein the strongly polar solvent in step (c) is one or more selected from water, methanol, ethanol, isopropanol, methyl ethyl ketone, acetone, and ethyl acetate, and the solvent exchange temperature is less than 10 ℃ and the solvent exchange time is 16-48h.
9. The method of claim 1, wherein the drying of step (c) comprises room temperature 25 ℃ drying for 24-48h, oven drying at 25-30 ℃ for 24-48h, or freeze drying at-45 ℃ and-5 Pa for 24-48 h.
10. A piezoelectric polymer-based foam having an oriented pore structure prepared by the method of any one of claims 1-9.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111363277A (en) * | 2020-04-27 | 2020-07-03 | 南京航空航天大学 | Polymer-based piezoelectric film and preparation method and application thereof |
| CN112646296A (en) * | 2020-12-21 | 2021-04-13 | 之江实验室 | Preparation method of 0-0-3 type flexible piezoelectric composite film |
| CN112940342A (en) * | 2021-02-24 | 2021-06-11 | 四川大学 | Method for preparing open-cell ZIF-8/polymer composite foam material by utilizing solid-phase shearing and grinding technology |
| CN113666358A (en) * | 2021-09-28 | 2021-11-19 | 四川大学 | Method for preparing three-dimensional flexible carbon-based aerogel through direct ink writing 3D printing technology |
| EP3964541A1 (en) * | 2020-09-03 | 2022-03-09 | Commissariat à l'Energie Atomique et aux Energies Alternatives | Production of a conductive aerogel |
| CN114262464A (en) * | 2021-12-22 | 2022-04-01 | 西南大学 | Preparation method and application of bio-based aerogel piezoelectric sensing device |
-
2022
- 2022-05-12 CN CN202210519627.2A patent/CN115594928A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111363277A (en) * | 2020-04-27 | 2020-07-03 | 南京航空航天大学 | Polymer-based piezoelectric film and preparation method and application thereof |
| EP3964541A1 (en) * | 2020-09-03 | 2022-03-09 | Commissariat à l'Energie Atomique et aux Energies Alternatives | Production of a conductive aerogel |
| CN112646296A (en) * | 2020-12-21 | 2021-04-13 | 之江实验室 | Preparation method of 0-0-3 type flexible piezoelectric composite film |
| CN112940342A (en) * | 2021-02-24 | 2021-06-11 | 四川大学 | Method for preparing open-cell ZIF-8/polymer composite foam material by utilizing solid-phase shearing and grinding technology |
| CN113666358A (en) * | 2021-09-28 | 2021-11-19 | 四川大学 | Method for preparing three-dimensional flexible carbon-based aerogel through direct ink writing 3D printing technology |
| CN114262464A (en) * | 2021-12-22 | 2022-04-01 | 西南大学 | Preparation method and application of bio-based aerogel piezoelectric sensing device |
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