An electrochemically driven color-changing and deformation dual-response actuator and a method for preparing the same

Abstract

The present invention relates to an electrochemically driven color-changing and deformable dual-response actuator and a preparation method thereof, wherein the actuator uses a polyvinylidene fluoride gel electrolyte containing lithium salt as an intermediate layer, and color-changing and deformable dual-network structure films are arranged on both sides; wherein the color-changing and deformable dual-network structure film is a single-walled carbon nanotube conductive layer loaded with vanadium pentoxide nanowires. The present invention has good optical properties and actuation properties, fast conversion rate, and good flexibility, which makes it have broad application prospects in sensing, anti-counterfeiting, fabric display, camouflage and even military fields.

Description

Technical Field

[0001] The invention belongs to the field of actuators, and in particular relates to an electrochemically driven color-changing and deformation dual-response actuator and a preparation method thereof. Background Art

[0002] With the development of society, highly portable, intelligent, and multifunctional wearable devices have become the mainstream of development. Shape and color, as important functions of wearable devices, play an indispensable role in many fields such as fashion, camouflage, and warning. Especially in recent years, with the continuous improvement and development of reconnaissance methods, the requirements for camouflage technology have become higher and higher. In addition, people have higher and higher requirements for the color changeability of wearable devices and devices. How to achieve the integration of deformability and color changeability of existing optoelectronic devices and equipment has become the focus of a series of research.

[0003] For traditional actuator technology, only a single deformation can occur. This single shape change limits the application of actuators in the field of military camouflage. As one of the most promising intelligent devices, the electrochemically driven color-changing and shape-changing dual-response actuator provides a good way to solve the problem of intelligent color and shape change. It can controllably and reversibly change the color and shape of the actuator under the stimulation of an external electric field, and can achieve multiple effects of multiple color and shape conversion through the application and compounding of different materials, so it has high research significance and commercial value. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an electrochemically driven color-changing and deformable dual-response actuator and a preparation method thereof. The actuator has good optical properties and actuation performance, and has a fast conversion rate and good flexibility, which makes it have broad application prospects in sensing, anti-counterfeiting, fabric display, camouflage and even military fields.

[0005] The present invention provides an electrochemically driven color-changing and deformable dual-response actuator, wherein the actuator uses a polyvinylidene fluoride gel electrolyte containing lithium salt as an intermediate layer, and color-changing and deformable dual-network structure films are arranged on both sides; wherein the color-changing and deformable dual-network structure film is a single-walled carbon nanotube conductive layer loaded with vanadium pentoxide nanowires.

[0006] The present invention also provides a method for preparing an electrochemically driven color-changing and deformable dual-response actuator, comprising:

[0007] (1) ultrasonically dispersing single-walled carbon nanotubes in water to obtain a single-walled carbon nanotube dispersion, and ultrasonically dispersing vanadium pentoxide nanowires in water to obtain a vanadium pentoxide nanowire dispersion;

[0008] (2) filtering the single-walled carbon nanotube dispersion onto a polyethylene film, then peeling off to obtain a single-walled carbon nanotube conductive layer, filtering the vanadium pentoxide nanowire dispersion onto the conductive layer, and then drying to obtain a deformation-changing color double-layer network structure film;

[0009] (3) Two layers of deformable and color-changing double-layer network structure films are bonded together through a polyvinylidene fluoride gel electrolyte containing lithium salt to obtain an electrochemically driven color-changing and deformable dual-response actuator.

[0010] The ultrasonic time of the single-walled carbon nanotubes in step (1) is 1.5-2.5 hours; the concentration of the single-walled carbon nanotube dispersion is 0.1-0.5 mg / ml.

[0011] The ultrasonic time of the vanadium pentoxide nanowires in step (1) is 1-5 min; the concentration of the vanadium pentoxide nanowire dispersion is 0.5-1.5 mg / ml; and the length of the vanadium pentoxide nanowires is 100 nm-5 μm.

[0012] The volume ratio of the single-walled carbon nanotube dispersion to the vanadium pentoxide nanowire dispersion in step (2) is 1-5:1-5.

[0013] The thickness of the single-walled carbon nanotube conductive layer in step (2) is 0.1-2.5 μm, the thickness of the active layer formed by filtering the vanadium pentoxide nanowire dispersion is 0.5-8 μm; the thickness of the deformation and color change double-layer network structure film is 0.6-10.5 μm, and the area is 5 cm 2 -30cm 2 .

[0014] The lithium salt concentration in step (3) is 1 mol / L.

[0015] The thickness of the gel electrolyte containing lithium salt in the step (3) is 2-100 μm.

[0016] The thickness of the electrochemically driven color-changing and deformable dual-response actuator in step (3) is 3.2-121 μm.

[0017] The present invention uses a suction filtration method to quickly prepare a single-walled carbon nanotube conductive layer on a polyethylene film, and prepares a color-changing and deformation dual-response active layer on the single-walled carbon nanotube conductive layer, and prepares an electrochemically driven color-changing and deformation dual-response actuator through gel electrolyte bonding.

[0018] Beneficial Effects

[0019] (1) The present invention has good optical and actuation properties, fast conversion rate and good flexibility, which makes it have broad application prospects in sensing, anti-counterfeiting, fabric display, camouflage and even military fields.

[0020] (2) The present invention uses a continuous filtration method to achieve uniform preparation of a single-walled carbon nanotube conductive layer and a vanadium pentoxide nanowire color-changing and deformation-changing dual-response layer, without requiring any post-processing such as sintering;

[0021] (3) The present invention can achieve the preparation of color-changing actuated dual-responsive films with different performances by adjusting parameters such as dispersion concentration and dosage, nanowire length, electrolyte layer thickness, and filtration area;

[0022] (4) The process of the present invention is simple and suitable for large-area preparation. It realizes the bending actuation amplitude and very small weight of the electrochemically driven color-changing and deformable dual-response actuator, thus expanding its application in multiple fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the electrochemically driven color-changing and deformation-changing dual-response actuator prepared in Example 1;

[0024] Figure 2 This is a scanning electron microscope image of the vanadium pentoxide nanowires prepared in Example 1;

[0025] Figure 3 This is a scanning electron microscope image of the dual network structure of the electrochemically driven color-changing and deformable dual-response actuator prepared in Example 1;

[0026] Figure 4 This is a cross-sectional scanning electron microscope image of the electrochemically driven color-changing and deformation-changing dual-response actuator prepared in Example 1;

[0027] Figure 5 Digital photos of the electrochemically driven color-changing and deformable dual-response actuator prepared in Example 1 in the initial state and under +1.8V and -1.8V voltage driving;

[0028] Figure 6 This is a test diagram of the actuation performance of the electrochemically driven color-changing and deformable dual-response actuator prepared in Example 1;

[0029] Figure 7 This is a color contrast test diagram of the electrochemically driven color-changing and deformable dual-response actuator prepared in Example 1 before and after color change;

[0030] Figure 8 The patterned design of the electrochemically driven color-changing and shape-changing dual-response actuator in Example 1, (a) a device made into a flower, a digital photo of the color-changing and shape-changing device under the +1.8V and -1.8V voltage drive, (b) a digital photo of the color-changing and shape-changing device of the bionic octopus under the +1.8V and -1.8V voltage drive. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0032] Example 1

[0033] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion liquid with a concentration of 0.15 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 2 minutes to prepare a vanadium pentoxide nanowire dispersion liquid with a length of about 3 μm and a concentration of 1 mg / ml. The single-walled carbon nanotube dispersion liquid with a concentration of 0.15 mg / ml was filtered in an amount of 2 ml to an area of ​​10 cm 2 The polyvinylidene fluoride film was then peeled off to obtain a conductive layer, and then 3 ml of a vanadium pentoxide nanowire dispersion with a concentration of 1 mg / ml was filtered onto the conductive layer, and the filtered film was heated on a hot plate at 30°C to obtain a deformable color-changing double-layer network structure film; finally, the deformable color-changing double-layer network structure film was bonded with a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 9 μm, and the thickness of the obtained film was only 18 μm and the area was 3.8 cm 2 Electrochemically driven color-changing and deformation dual-response actuator.

[0034] Figure 1 The schematic diagram of the structure of the electrochemically driven color-changing and deformation dual-response actuator is shown in Figure 1. The active layer is a vanadium pentoxide nanowire functional layer, the conductive layer is a single-walled carbon nanotube layer, the electrolyte layer is a polyvinylidene fluoride layer, and the electrolyte ions are Li + ; Figure 2 The scanning electron microscope image of the prepared vanadium pentoxide nanowires shows that the aspect ratio of the vanadium pentoxide nanowires is relatively large and the size distribution is uniform; Figure 3 The scanning electron microscope image of the double network structure composed of the prepared vanadium pentoxide nanowires and single-walled carbon nanotubes shows that the vanadium pentoxide nanowires are tightly and evenly interwoven on the single-walled carbon nanotubes; Figure 4 The scanning electron microscope image of the prepared electrochemically driven color-changing and deformation dual-response actuator shows that the dual network structure is tightly entangled and closely combined with the electrolyte intermediate layer; Figure 5 This is a digital photo of the prepared electrochemically driven color-changing and deformable dual-response actuator. It can be seen that the electrochemically driven color-changing and deformable actuator has a large actuation distance. Figure 6The actuation performance test of the electrochemically driven color-changing and deformable dual-response actuator was conducted. It was found that the actuation distance of the electrochemically responsive color-changing and deformable actuator reached 9.7 mm, and the actuation was caused by the lattice expansion of the active layer. Figure 7 The color contrast test of the electrochemically driven color-changing and deformable dual-response actuator shows that the color changes when the device bends and deforms. Figure 8 Digital photos of the color-changing and deformation demonstration to design the electrochemically driven color-changing and deformation dual-response actuator into different patterns.

[0035] Example 2

[0036] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion with a single-walled carbon nanotube concentration of 0.15 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 2 minutes to prepare a vanadium pentoxide nanowire dispersion with a length of about 3 μm and a concentration of 1.5 mg / ml. The single-walled carbon nanotube dispersion with a concentration of 0.15 mg / ml was filtered in an amount of 2 ml to an area of ​​10 cm 2 The conductive layer was then peeled off and filtered onto the conductive layer with a concentration of 1.5 mg / ml of vanadium pentoxide nanowire dispersion in an amount of 3 ml. The filtered film was heated on a hot plate at 30°C to obtain a dual-responsive film. Finally, the dual-responsive film was bonded with a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 2 μm, and the obtained thickness was only 11 μm, with an area of ​​3.8 cm 2 The electrochemically driven color-changing and deformable dual-response actuator. As the concentration of vanadium pentoxide nanowires increases, the color-changing actuation active layer becomes thicker, and the color-changing and actuation performances become better. As the device thickness becomes thinner, it will cause a short circuit in the device, causing the actuation device to fail to work properly.

[0037] Example 3

[0038] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion liquid with a single-walled carbon nanotube concentration of 0.5 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 2 minutes to prepare a vanadium pentoxide nanowire dispersion liquid with a length of about 3 μm and a concentration of 1 mg / ml. The single-walled carbon nanotube dispersion liquid with a concentration of 0.5 mg / ml was filtered to an area of ​​30 cm 2The conductive layer is then obtained by peeling off the polyvinylidene fluoride film, and then 3 ml of vanadium pentoxide nanowire dispersion with a concentration of 1 mg / ml is filtered onto the conductive layer, and the filtered film is heated on a hot plate at 30°C to obtain a deformable color-changing double-layer network structure film; finally, the deformable color-changing double-layer network structure film is bonded by a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte is 100 μm, and the obtained thickness is 109 μm, and the area is 3.8 cm 2 The electrochemically driven color-changing and deformation dual-response actuator. As the carbon tube content increases, the conductive material in the single-walled carbon nanotube dispersion increases, the conductivity improves, and the rate of deformation and color change accelerates. However, due to the increase in the area during filtration, the loading amount of vanadium pentoxide nanowires on the device decreases, resulting in a decrease in the deformation and color change ability. In addition, the thickening of the electrolyte layer leads to a thicker device thickness and heavier device weight, which deteriorates the device's actuation performance.

[0039] Example 4

[0040] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion liquid with a single-walled carbon nanotube concentration of 0.15 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 5 minutes to prepare a vanadium pentoxide nanowire dispersion liquid with a length of about 200 nm and a concentration of 1.5 mg / ml. The single-walled carbon nanotube dispersion liquid with a concentration of 0.15 mg / ml was filtered in an amount of 2 ml to an area of ​​5 cm 2 The polyvinylidene fluoride film was then peeled off to obtain a conductive layer, and then 5 ml of a vanadium pentoxide nanowire dispersion with a concentration of 0.5 mg / ml was filtered onto the conductive layer, and the filtered film was heated on a 30°C hot plate to obtain a deformable and color-changing double-layer network structure film; finally, the deformable and color-changing double-layer network structure film was bonded through a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 9 μm, and the obtained thickness was only 28 μm, with an area of ​​3.8 cm 2 The electrochemically driven color-changing and deformation dual-response actuator. As the filtration area is reduced, the local vanadium oxide concentration increases, making the color-changing and deformation performance better, but the device structure becomes thicker, the color-changing actuation performance response speed slows down, and the increase in the ultrasonic time of the vanadium pentoxide nanowires shortens the length of the nanowires, the connectivity between the nanowires deteriorates, and the cycle stability deteriorates.

[0041] Example 5

[0042] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion with a single-walled carbon nanotube concentration of 0.5 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 1 minute to prepare a vanadium pentoxide nanowire dispersion with a length of about 5 μm and a concentration of 1.5 mg / ml. The single-walled carbon nanotube dispersion with a concentration of 0.5 mg / ml was filtered to an area of ​​10 cm 2 The polyvinylidene fluoride film was then peeled off to obtain a conductive layer, and then 5 ml of a vanadium pentoxide nanowire dispersion with a concentration of 1.5 mg / ml was filtered onto the conductive layer, and the filtered film was heated on a 30°C hot plate to obtain a deformable and color-changing double-layer network structure film; finally, the deformable and color-changing double-layer network structure film was bonded through a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 15 μm, and the obtained thickness was only 36 μm, with an area of ​​3.8 cm 2 The electrochemically driven color-changing and deformable dual-response actuator. The increase in the content of single-walled carbon nanotubes leads to an increase in conductivity, but the increase in the amount of vanadium pentoxide nanowires leads to a thicker device structure, a slower response speed of the color-changing actuation performance, and a reduction in the ultrasonic time of the vanadium pentoxide nanowires, which lengthens the nanowires and causes agglomeration between the nanowires, resulting in poor cycle stability.

[0043] Example 6

[0044] Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 hours to prepare a single-walled carbon nanotube dispersion with a single-walled carbon nanotube concentration of 0.1 mg / ml. Vanadium pentoxide nanowires were added to water and ultrasonically dispersed for 2 minutes to prepare a vanadium pentoxide nanowire dispersion with a length of about 3 μm and a concentration of 0.5 mg / ml. The single-walled carbon nanotube dispersion with a concentration of 0.1 mg / ml was filtered to an area of ​​10 cm 2 The polyvinylidene fluoride film was then peeled off to obtain a conductive layer, and then 1 ml of a vanadium pentoxide nanowire dispersion with a concentration of 0.5 mg / ml was filtered onto the conductive layer, and the filtered film was heated on a 30°C hot plate to obtain a deformable and color-changing double-layer network structure film; finally, the deformable and color-changing double-layer network structure film was bonded through a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 9 μm, and the obtained thickness was only 18 μm, with an area of ​​3.8 cm 2 The electrochemically driven color-changing and shape-changing dual-response actuator. Due to the reduction in the content of single-walled carbon nanotubes, the conductivity is reduced and the response speed is slowed down. Due to the reduction in the amount of vanadium pentoxide nanowires, the color-changing performance and actuation performance are greatly reduced.

Claims

1. An electrochemically driven color-changing and deformation dual-response actuator, characterized in that: The actuator uses a polyvinylidene fluoride gel electrolyte containing lithium salt as the middle layer, and color-changing and deformable double network structure films are arranged on both sides; wherein the color-changing and deformable double network structure film is a single-walled carbon nanotube conductive layer loaded with vanadium pentoxide nanowires; the preparation method comprises: Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 h to prepare a single-walled carbon nanotube dispersion with a concentration of 0.15 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 2 min to prepare a vanadium pentoxide nanowire dispersion with a length of 3 μm and a concentration of 1 mg / ml. The single-walled carbon nanotube dispersion with a concentration of 0.15 mg / ml was filtered in an amount of 2 ml to an area of ​​10 cm 2 The film was then peeled off to obtain a conductive layer, and then 3 ml of vanadium pentoxide nanowire dispersion with a concentration of 1 mg / ml was filtered onto the conductive layer, and the film obtained by filtration was heated on a hot plate at 30°C to obtain a deformable color-changing double-layer network structure film; finally, the deformable color-changing double-layer network structure film was bonded with a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 9 μm, and a film with a thickness of 18 μm and an area of ​​3.8 cm was obtained. 2 Electrochemically driven color-changing and deformation dual-response actuator.

2. A method for preparing the electrochemically driven color-changing and deformable dual-response actuator according to claim 1, comprising: Single-walled carbon nanotubes were added to water and ultrasonically dispersed for 2 h to prepare a single-walled carbon nanotube dispersion with a concentration of 0.15 mg / ml. Vanadium pentoxide nanowires were added to deionized water and ultrasonically dispersed for 2 min to prepare a vanadium pentoxide nanowire dispersion with a length of 3 μm and a concentration of 1 mg / ml. The single-walled carbon nanotube dispersion with a concentration of 0.15 mg / ml was filtered in an amount of 2 ml to an area of ​​10 cm 2 The film was then peeled off to obtain a conductive layer, and then 3 ml of vanadium pentoxide nanowire dispersion with a concentration of 1 mg / ml was filtered onto the conductive layer, and the film obtained by filtration was heated on a hot plate at 30°C to obtain a deformable color-changing double-layer network structure film; finally, the deformable color-changing double-layer network structure film was bonded with a polyvinylidene fluoride gel electrolyte containing 1 mol / L lithium salt, wherein the thickness of the gel electrolyte was 9 μm, and a film with a thickness of 18 μm and an area of ​​3.8 cm was obtained. 2 Electrochemically driven color-changing and deformation dual-response actuator.

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