阅读说明：本技术 一种钛酸钡基体复合材料及其diw打印成型方法和应用 (Barium titanate matrix composite material and DIW printing forming method and application thereof ) 是由 张楚虹 刘新刚 刘警峰 贺丽蓉 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种钛酸钡基体复合材料及其DIW打印成型方法和应用。将羟基化钛酸钡(BTO-OH)粉末、棉花纤维素(CNF)粉末和水系聚氨酯(WPU)加入去离子水中,采用高速匀浆机器搅拌,即可制得功能墨水,将该功能墨水经DIW 3D打印后,即得复合材料。钛酸钡粉末作为压电活性材料在墨水中均匀分散,打印后的钛酸钡基体复合材料经过冷冻干燥处理后形成柔软的、可压缩/恢复的泡沫,并具备优异的压电输出性能。通过本发明方法制得的产品能够作为机械能收集器件、传感器、驱动器等,以用于新能源孚能、传感、人工智能等领域。(The invention discloses a barium titanate matrix composite material and a DIW printing forming method and application thereof. Adding hydroxylated barium titanate (BTO-OH) powder, cotton Cellulose (CNF) powder and water-based polyurethane (WPU) into deionized water, stirring by a high-speed homogenizing machine to obtain functional ink, and carrying out DIW3D printing on the functional ink to obtain the composite material. Barium titanate powder is uniformly dispersed in ink as a piezoelectric active material, and the printed barium titanate matrix composite material forms soft, compressible/recoverable foam after freeze drying treatment and has excellent piezoelectric output performance. The product prepared by the method can be used as a mechanical energy collecting device, a sensor, a driver and the like, and is used in the fields of new energy, such as energy, sensing, artificial intelligence and the like.)

1. A method for preparing a barium titanate matrix composite material by DIW printing is characterized by comprising the following steps:

(1) dissolving hydroxylated barium titanate, cotton cellulose and water-based polyurethane in deionized water to form slurry;

(2) and stirring and dispersing the slurry to prepare ink with shear thinning capability, and printing and molding the ink in a DIW3D printer to obtain the ink.

2. The method for preparing a barium titanate matrix composite material through DIW printing according to claim 1, wherein the mass ratio of the hydroxylated barium titanate to the cotton cellulose is 1: 10-3: 10, the mass ratio of the hydroxylated barium titanate to the water-based polyurethane is 10: 3-30: 1, and the mass ratio of the hydroxylated barium titanate to the deionized water is 1: 50-3: 50.

3. The method of DIW printing to produce a barium titanate matrix composite according to claim 1, wherein the hydroxylated barium titanate is produced by:

mixing barium titanate powder and hydrogen peroxide according to the mass ratio of 1: 30-1: 50, stirring and dispersing for 1-2 hours, and reacting at 60-80 ℃ for 60-100 min to prepare a mixed liquid;

and b, naturally cooling the mixed liquid to room temperature, and then sequentially filtering, washing and drying to obtain the product.

4. The method for preparing a barium titanate matrix composite by DIW printing as claimed in claim 1, wherein the stirring dispersion in step (2) comprises the steps of: stirring for 10-20 min at a stirring speed of 8000-30000 r/min.

5. The method for preparing a barium titanate matrix composite material through DIW printing according to claim 1, wherein the diameter of a printing needle in the 3D printing forming process is 0.6-0.9 mm, the extrusion pressure during printing is 10-30 psi, and the moving speed of the printing needle is 5-20 mm/min.

6. The barium titanate matrix composite produced by the method of producing a barium titanate matrix composite using the DIW printing of any one of claims 1-5.

7. The use of the barium titanate matrix composite of claim 6 in a piezoelectric device.

8. Use according to claim 7, wherein the preparation of a piezoelectric fu energy device comprises the steps of: and (3) freeze-drying the barium titanate matrix composite material to obtain the barium titanate matrix composite material.

Technical Field

The invention belongs to the technical field of new materials, and particularly relates to a barium titanate matrix composite material, a DIW printing forming method and application thereof.

Background

Piezoelectric materials are functional materials for conversion between mechanical energy and electrical energy, and due to their special functionality, they are used in various aspects of daily life and industrial production, such as sound converters, sonar, transducers, and the like. Among many piezoelectric materials, barium titanate ceramic particles are attracting attention because of their advantages of high piezoelectric coefficient, high dielectric constant, lead-free, low cost, and easy synthesis, but their disadvantages of hardness and brittleness make processing and application unfavorable. However, due to the limitation of the fabrication process, the current piezoelectric device is mainly composed of a two-dimensional (2D) thin film structure. The low dimensional structure results in a small degree of deformation, and therefore the conversion efficiency of piezoelectric devices is not high, and most of them are used for miniature electronic devices. While mechanical energy is generally discrete and irregular, the three-dimensional (3D) structure of a multi-dimensional structure is effective in sensing mechanical vibrations and collecting mechanical energy. The three-dimensional structure provides more effective deformation in height space, and the force-electricity conversion efficiency is greatly improved, so that the directional offset of the electric dipole of the piezoelectric material is promoted, and a larger output voltage is generated.

The 3D printing technology, also called additive manufacturing (additive manufacturing) technology, is a way to increase material layer-by-layer manufacturing through three-dimensional model data, is quite opposite to the traditional subtractive manufacturing process, and has the advantages of low cost, high efficiency and flexible design, and can prepare extremely complex structures, etc., providing infinite potential for manufacturing three-dimensional piezoelectric devices with high power-to-power conversion capability. The existing 3D printing technology mainly includes stereo Stereolithography (SLA), Selective Laser Sintering (SLM), Fused Deposition Modeling (FDM), Direct Ink Writing (DIW), and the like. Among them, the DIW printing technology relies on the advantages of wide selection of printing materials, room temperature printing, simple process, low cost, etc., and becomes one of the most developed 3D printing technologies at present.

The composite piezoelectric material device of the flexible barium titanate ceramic matrix with the three-dimensional structure and excellent piezoelectric performance is constructed through a 3D printing technology, has good application in emerging piezoelectric collection mechanical energy, piezoelectric sensors, piezoelectric drivers and the like, and has great development potential in high-end fields such as artificial intelligence and the like.

Disclosure of Invention

The invention aims to provide a barium titanate matrix composite material, a DIW printing forming method and application thereof, which have the advantages of simple process, high barium titanate content, flexibly designed printing structure, high flexibility, high piezoelectric conversion efficiency and the like, and can meet the application requirements of the barium titanate matrix composite material in the aspects of various functional devices.

In order to achieve the above object, the present invention provides a method for preparing a barium titanate matrix composite material by DIW printing, comprising the following steps:

(1) dissolving hydroxylated barium titanate, cotton cellulose and water-based polyurethane in deionized water to form slurry;

(2) and stirring and dispersing the slurry to prepare ink with shear thinning capability, and printing and molding the ink in a DIW3D printer to obtain the ink.

Further, the mass ratio of the hydroxylated barium titanate to the cotton cellulose is 1: 10-3: 10, the mass ratio of the hydroxylated barium titanate to the aqueous polyurethane is 10: 3-30: 1, and the mass ratio of the hydroxylated barium titanate to the deionized water is 1: 50-3: 50.

Further, the hydroxylated barium titanate is prepared by the following method:

mixing barium titanate powder and hydrogen peroxide according to the mass ratio of 1: 30-1: 50, stirring and dispersing for 1-2 hours, and reacting at the temperature of 60-80 ℃ for 60-100 min to prepare a mixed liquid;

and b, naturally cooling the mixed liquid to room temperature, and then sequentially filtering, washing and drying to obtain the product.

Further, the stirring and dispersing in the step (2) comprises the following steps: stirring for 10-20 min at a stirring speed of 8000-30000 r/min.

Further, the diameter of a printing needle head in 3D printing and forming is 0.6-0.9 mm, the extrusion pressure during printing is 10-30 psi, and the moving speed of the printing needle head is 5-20 mm/min.

The barium titanate matrix composite material is prepared by adopting a method for preparing the barium titanate matrix composite material by DIW printing.

The barium titanate matrix composite material is applied to a piezoelectric energy device, and can be used as the piezoelectric energy device after being frozen and dried.

In summary, the invention has the following advantages:

1. hydroxyl on the hydroxylation-treated barium titanate powder adopted in the invention forms hydrogen bonds with hydroxyl in cotton cellulose and water-based polyurethane in a composite system, thereby being beneficial to the dispersion of barium titanate in ink; the introduction of the cellulose is beneficial to realizing the thickening effect on the composite ink, so that the composite ink has the shear thinning capability capable of being subjected to DIW printing; the water-based polyurethane (WPU) can be used as a flexible substrate material, and the flexibility of the composite material is endowed after a printed structural device is subjected to freeze drying;

2. after the barium titanate matrix composite material is subjected to freeze drying, the barium titanate matrix composite material is used as a piezoelectric energy device, and compared with the traditional pure barium titanate ceramic material, the barium titanate matrix composite material has excellent flexibility and can show excellent piezoelectric output performance.

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 a shear thinning capacity curve diagram of hydroxylated barium titanate @ cotton cellulose @ aqueous polyurethane composite functional ink;

FIG. 2 is a graph showing the storage modulus/loss modulus of a hydroxylated barium titanate @ cotton cellulose @ aqueous polyurethane composite functional ink;

FIG. 3 is a three-dimensional foam part after DIW printing and freeze drying with hydroxylated barium titanate @ cotton cellulose @ aqueous polyurethane composite functional ink;

FIG. 4 is an internal Scanning Electron Microscope (SEM) image of a printed three-dimensional foamed article;

fig. 5 is a graph of open circuit voltage as a fuerg device for DIW printing of a piezoelectric foam of a hydroxylated barium titanate @ cotton cellulose @ water-based polyurethane composite functional ink system.

Detailed Description

The principles and features of this invention are described below in conjunction with embodiments, which are included to explain the invention and not to limit the scope of the invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

The embodiment provides a method for preparing a barium titanate matrix composite material by DIW printing, which comprises the following steps:

(1) mixing barium titanate powder (BTO) and hydrogen peroxide according to a mass ratio of 1:40, stirring and dispersing for 1h by using a magnetic stirrer, transferring the mixed liquid into a reaction kettle, and reacting for 60min at the temperature of 60 ℃;

(2) heating the reaction kettle obtained in the step (1) to obtain mixed liquid, naturally cooling to room temperature, taking out the mixed liquid, filtering, washing and drying to obtain powdery substances;

(3) mixing hydroxylated barium titanate (BTO-OH), cotton cellulose powder (CNF), water-system polyurethane (WPU) and deionized water according to the mass ratio of 20:2:100:5, and dispersing the mixture for 40min at 30000r/min by using a high-speed refiner to prepare uniform hydroxylated barium titanate @ cotton cellulose @ water-system polyurethane composite functional ink;

(4) adding the composite functional ink into a printing needle cylinder for DIW printing to obtain a barium titanate matrix composite material, wherein the shear thinning capability of the ink is shown in figure 1, and the storage modulus/loss modulus curve is shown in figure 2; during printing, the diameter of the needle tube was 0.84mm, the extrusion pressure was 15psi, and the needle movement rate was 10 mm/min.

As can be seen from FIG. 1, the viscosity of the ink decreases with the increase of the shear rate, which indicates that the ink has the ability of shear thinning, and is one of the important indexes for representing the ability of printing; as can be seen from fig. 2, when the shear stress is greater than the yield stress, the ink exhibits a behavior of a partial liquid state, which facilitates smooth extrusion of the ink; when the storage modulus is larger than the loss modulus, the ink is in a solid state behavior, and the characteristic that the ink can be extruded from the needle head and the printed structure can keep the shape is represented.

Test example 1

(1) Freeze-drying the barium titanate matrix composite material prepared in example 1 to obtain a barium titanate matrix lightweight piezoelectric foam part, as shown in fig. 3, wherein the interior of the foam shows a three-dimensionally interconnected porous structure, and a Scanning Electron Microscope (SEM) image of the foam is shown in fig. 4;

(2) and (3) performing piezoelectric test on the three-dimensional workpiece which is printed and dried by using a universal compressor and a Labview system, attaching electrodes to the upper side and the lower side of the workpiece, compressing the workpiece by using the compressor, and performing 6 groups of tests on the compression strain within the range of 1-10% to obtain signals of output voltage of the workpiece, wherein the curve chart is shown in FIG. 5.

As can be seen, the highest output voltage obtained for the piezoelectric foam at 10% compressive strain was 13.2V.

Example 2

The embodiment provides a method for preparing a barium titanate matrix composite material by DIW printing, which comprises the following steps:

(1) mixing barium titanate powder and hydrogen peroxide according to a mass ratio of 1:30, stirring and dispersing for 1h by using a magnetic stirrer, transferring the mixed liquid into a reaction kettle, and reacting for 80min at 70 ℃;

(2) heating the reaction kettle obtained in the step (1) to obtain mixed liquid, naturally cooling to room temperature, taking out the mixed liquid, filtering, washing and drying to obtain powdery substances;

(3) mixing BTO-OH, CNF, WPU and deionized water according to the mass ratio of 30:3:100:5, and dispersing for 60min at 20000r/min by using a high-speed homogenizer to prepare uniform hydroxylated barium titanate @ cotton cellulose @ water-based polyurethane composite functional ink;

(4) adding the composite functional ink into a printing needle cylinder for DIW printing to obtain a barium titanate matrix composite material; during printing, the diameter of the needle tube was 0.84mm, the extrusion pressure was 20psi, and the needle movement rate was 7 mm/min.

The highest output voltage of the piezoelectric foamed article obtained under a 10% compressive strain condition was 10.3V using the barium titanate matrix composite of example 2 as a starting material by the method provided in test example 1.

Example 3

The embodiment provides a method for preparing a barium titanate matrix composite material by DIW printing, which comprises the following steps:

(1) mixing barium titanate powder and hydrogen peroxide according to the mass ratio of 1:50, stirring and dispersing for 1h by using a magnetic stirrer, transferring the mixed liquid into a reaction kettle, and reacting for 50min at the temperature of 80 ℃;

(2) heating the reaction kettle obtained in the step (1) to obtain mixed liquid, naturally cooling to room temperature, taking out the mixed liquid, filtering, washing and drying to obtain powdery substances;

(3) mixing BTO-OH, CNF, WPU and deionized water according to the mass ratio of 10:1:100:5, and dispersing for 60min at 10000r/min by using a high-speed homogenizer to prepare uniform hydroxylated barium titanate @ cotton cellulose @ water-based polyurethane composite functional ink;

(4) adding the composite functional ink into a printing needle cylinder for DIW printing to obtain a barium titanate matrix composite material; during printing, the diameter of the needle tube was 0.6mm, the extrusion pressure was 26psi, and the needle movement rate was 6 mm/min.

Using the method provided in test example 1, the barium titanate matrix composite of example 3 as a starting material, a piezoelectric foamed article was produced having a maximum output voltage of 7.7V achieved at a 10% compressive strain.

Example 4

The embodiment provides a method for preparing a barium titanate matrix composite material by DIW printing, which comprises the following steps:

(1) mixing barium titanate powder and hydrogen peroxide according to a mass ratio of 1:35, stirring and dispersing for 1h by using a magnetic stirrer, transferring the mixed liquid into a reaction kettle, and reacting for 90min at the temperature of 60 ℃;

(2) heating the reaction kettle obtained in the step (1) to obtain mixed liquid, naturally cooling to room temperature, taking out the mixed liquid, filtering, washing and drying to obtain powdery substances;

(3) mixing BTO-OH, CNF, WPU and deionized water according to the mass ratio of 20:3:100:5, and dispersing for 50min at 20000r/min by using a high-speed homogenizer to prepare uniform hydroxylated barium titanate @ cotton cellulose @ water-based polyurethane composite functional ink;

(4) adding the composite functional ink into a printing needle cylinder for DIW printing to obtain a barium titanate matrix composite material; during printing, the diameter of the needle tube was 1.2mm, the extrusion pressure was 10psi, and the needle travel rate was 11 mm/min.

The highest output voltage of the piezoelectric foamed article obtained under a 10% compressive strain condition was 8.9V using the barium titanate matrix composite of example 4 as a starting material in the method provided in test example 1.

While the present invention has been described in detail with reference to the specific embodiments thereof, it should not be construed as limited by the scope of the present patent. Various modifications and changes may be made by those skilled in the art without inventive step within the scope of the appended claims.