Preparation method of radial orientation MXene fiber artificial muscle

Abstract

The invention discloses a preparation method of a radial orientation MXene fiber artificial muscle. The method comprises the following steps: firstly, taking a Ti < 3 > C < 2 > T < x > MXene nanosheet and a cellulose nanofiber as assembly elements, and preparing the radial orientation MXene fiber artificial muscle through needle wet spinning assembly of an expansion pipeline; when the uniformly mixed MXene / CNFs composite nanosheets pass through a narrow-side wide expansion pipeline needle head, the shearing force of the composite nanosheets parallel to the spinning direction in the spinning process can be eliminated by expansion and diffusion stress, and then the composite nanosheets are arranged in the direction perpendicular to the spinning direction before fiber solidification. When the MXene fiber artificial muscle with the radial orientation structure and the rich hydrogen bond network is heated to 125 DEG C from 25 DEG C, a weight with the weight of 1 g can be rapidly lifted, the stretching stroke reaches 21%, and the working power is 1.1 J g <-1 >. Under the stimulation of 808 nm near-infrared light, the artificial limb with the self weight 1000 times or more can be repeatedly pulled up for 200 times or more, and the rapid, stable and multi-stimulation response capacity is shown.

Description

Technical Field

[0001] The present invention belongs to the field of artificial muscle preparation, and specifically relates to a method for preparing radially oriented MXene fiber artificial muscle. Background Art

[0002] When subjected to external stimuli (such as temperature, humidity, light, pH value and pressure), artificial muscles can reversibly perform some muscle-like movements, such as contraction, expansion, bending or rotation. They have great application potential in the fields of robotics, smart fabrics, reconfigurable IoT devices, implantable medical devices (such as prostheses), etc. (Chem. Soc. Rev. 2022, 57, 2377-2290). Generally speaking, different materials can be selected to prepare artificial muscles, such as carbon nanotubes (CNTs), natural polymers and synthetic polymers (Science, 2012, 338, 928-932). These twisted or coiled artificial muscles show excellent actuation performance, which is due to the stimulus-induced fiber untwisting mechanism that brings adjacent coils closer together (Science, 2014, 343, 868-872). However, the tensile actuation of these torsional or helical structured artificial muscles is still low. Although polymer fibers or yarns with high elasticity index can achieve large tensile strokes at lower temperatures, these high elasticity index torsional fibers have the following major problems. First, the only way to make high-spring-index coiled fiber artificial muscles is to coil a twisted polymer fiber around a mandrel that is much larger than the diameter of the polymer fiber (Nat. Nanotechnol. 2015, 10, 1077-1083). The problem is that there is currently no work on using a mandrel to make high-spring-index fibers, except for dissolving the mandrel after the muscle is coiled. Second, the volume-normalized performance of these high-spring-index muscles, such as the mechanical energy generated during muscle stroke, is far inferior to the weight-normalized performance (Science, 2019, 365, 150-155). Third, many key applications of artificial muscles must be woven into a base textile containing polymer yarns, whose diameter is smaller than the spacing between high-spring-index fiber coils, so fiber sliding between base textile yarns or muscle coils may interfere with muscle actuation.

[0003] Transition metal carbides / nitrides - MXene (Ti3C2T x ) is a new type of two-dimensional (2D) nanomaterial with excellent electrical conductivity (>10 5 S cm -1) and Young's modulus (~ 0.3 TPa). The nearly 100% photothermal conversion rate and fast Joule effect enable MXene to be used in sensors, electronic devices, and energy storage (Science, 2021, 372, eabf1581). The surface of MXene nanosheets contains abundant polar functional groups (-OH, -F, -O), which can easily form rich hydrogen bond networks with hydroxyl-containing polymers. Cellulose nanofibers (CNFs) are a kind of renewable plant fiber with high mechanical strength and large surface area, which also contains abundant hydroxyl functional groups (Adv. Mater. 2018, 30, 1703779). Although some simple and weak lateral driving behaviors are achieved by assembling the two into a film, it is still challenging to show larger thermally driven strain in volume or length because its driving behavior is mainly based on the thermal expansion difference caused by the asymmetric double layer structure.

[0004] In recent years, there are few patents on MXene-based artificial muscles, for example, a self-sensing material and its preparation method and application in artificial muscle fibers (CN117758518A), a twistable double-helical fibrous artificial muscle and its preparation method (CN112921461B), a core-sheath composite artificial muscle fiber system and its preparation method and application (CN117512838A), a fast-response thermally driven spiral winding artificial muscle (CN116276939A), a multi-stimulus responsive liquid crystal elastomer / MXene composite fiber soft actuator and its preparation method and application (CN116289170B). However, these artificial muscles all require complex twisting of polymer fibers or yarns, and have the disadvantages of low response rate and single response type.

[0005] In summary, it is still a challenge to realize fast and multi-stimulus responsive non-torsion artificial muscles. x MXene nanosheets and cellulose nanofibers were used as assembly elements, and radially oriented MXene fiber artificial muscles with large tensile stroke were prepared by needle wet spinning through an expanded tube. Summary of the invention

[0006] The technical solution of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing radially oriented MXene fiber artificial muscles. Even before any twisting, the MXene fiber artificial muscle with a radially oriented structure and a rich hydrogen bond network can lift a 1 g weight when heated from 25°C to 125°C, with a stretching stroke of 21% and a work power of 1.1 J g -1 Under the stimulation of 808 nm near-infrared light, it can repeatedly pull up an artificial limb that is more than 1,000 times its own weight more than 200 times.

[0007] The present invention is achieved by the following technical scheme: firstly, Ti3C2T is obtained by in-situ hydrofluoric acid etching method. x MXene solution, and then Ti3C2T x MXene and cellulose nanofibers (CNFs) were uniformly mixed and concentrated at high speed to obtain MXene / CNFs spinning ink, which was then assembled by needle wet spinning with an expansion channel, passed through an ethanol coagulation bath, and vacuum dried to obtain radially oriented MXene fiber artificial muscles.

[0008] The specific implementation steps of the present invention are as follows: A method for preparing a radially oriented MXene fiber artificial muscle comprises the following steps: (1) Preparation of Ti3C2T by in-situ hydrofluoric acid etching x MXene solution; (2) dispersing the cellulose nanofibers in deionized water, and preparing a uniformly dispersed cellulose nanofiber solution by ultrasonication of a cell disruptor; (3) Ti3C2T x The MXene solution and the cellulose nanofiber solution are mixed evenly to obtain a MXene / CNFs mixed solution; (4) The MXene / CNFs mixed solution of step (3) is concentrated by a centrifuge at high speed to remove excess water, thereby obtaining a high-concentration MXene / CNFs spinning ink; (5) transferring the MXene / CNFs spinning ink of step (4) into a syringe with an expansion channel needle, and extruding the MXene / CNFs spinning ink into an ethanol coagulation bath through a micro-syringe pump; (6) The MXene fibers assembled by wet spinning in step (5) are slowly collected onto a reel and vacuum dried to obtain radially oriented MXene fiber artificial muscles.

[0009] Furthermore, in step (1), Ti3C2T xThe preparation process of MXene solution is as follows: 3.2 g of lithium fluoride (LiF) is added to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, 2 g of Ti3AlC2 MAX powder is slowly added and stirred in a water bath at 50°C for 30 hours. After the reaction is completed, it is cooled to room temperature, and the reaction solution is evenly dispersed into 6 centrifuge tubes, deionized water is added, and centrifuged at 3500 rpm for 5 minutes. The supernatant is poured out, and this process is repeated 8 to 10 times until the pH of the supernatant exceeds 6. After that, deionized water is added to the above precipitate and shaken for 5 minutes, centrifuged at 1500 rpm for 30 minutes, and the supernatant is collected. Repeat this process to collect more supernatant until the supernatant is light green. The collected supernatant is centrifuged at 4500 rpm for 20 minutes, and the precipitate is collected; the precipitate is diluted with deionized water to obtain 3 mg / mL of Ti3C2T x MXene solution.

[0010] Furthermore, in the step (2), the cellulose nanofibers are ultrasonically dispersed in deionized water at a concentration of 10 mg / mL.

[0011] Furthermore, in the step (3), the mass ratio of the MXene / CNFs mixed solution is 7:3 to 3:7; preferably, in the step (3), the mass ratio of the MXene / CNFs mixed solution is 5:5.

[0012] Furthermore, in the step (4), the concentration of the MXene / CNFs spinning ink is 20 mg / mL to 50 mg / mL; preferably, in the step (4), the concentration of the MXene / CNFs spinning ink is 30 mg / mL.

[0013] Furthermore, in the step (5), the initial diameter of the spinning needle is 210 μm, the expansion transition diameter is 510 μm, and the microinjection pump extrude the MXene / CNFs spinning ink into the ethanol coagulation bath at 100 μL / min~400 μL / min; preferably, in the step (5), the extrusion speed is 300 μL / min.

[0014] Furthermore, in the step (6), the collection speed of the wet-spun assembled MXene fibers is 100 μL / min~400 μL / min; preferably, in the step (6), the collection speed of the MXene fibers is 300 μL / min; the collected fibers are vacuum dried at a temperature of 40°C for 24 hours to obtain radially oriented MXene fiber artificial muscles.

[0015] Furthermore, in step (6), wide-angle X-ray diffraction (WAXS) was used to characterize the orientation degree of the radially oriented MXene fiber artificial muscle, and its orientation degree f was 0.63; when heated from 25°C to 125°C, a weight of 1 g could be lifted, the stretching stroke reached 21%, and the work power was 1.1 J g -1 , under the stimulation of 808 nm near-infrared light, it can repeatedly pull up an artificial prosthesis that is more than 1,000 times its own weight more than 200 times.

[0016] Principle of the invention: The invention first adopts Ti3C2T x MXene nanosheets and cellulose nanofibers are used as assembly primitives to prepare radially oriented MXene fiber artificial muscles with large tensile strokes through wet spinning assembly with an expansion pipe needle. When the uniformly mixed MXene / CNFs composite nanosheets pass through the expansion pipe needle with a narrow side width, the stress of expansion diffusion will eliminate the shear force that causes the composite nanosheets to be parallel to the spinning direction during the spinning process, and then provide the composite nanosheets with an arrangement perpendicular to the spinning direction before the fiber solidifies. Even before any torsion, this MXene fiber artificial muscle with a radially oriented structure and a rich hydrogen bond network can quickly lift a 1 g weight when heated from 25°C to 125°C, with a tensile stroke of 7~21% and a work of 0.3~1.1 J g -1 . And the excellent photothermal effect of MXene gives MXene fiber artificial muscles the ability to quickly lift heavy objects under near-infrared light stimulation.

[0017] The advantages of the present invention compared with the prior art are: (1) A continuous preparation method for MXene fiber artificial muscles was developed.

[0018] (2) Even before any twist is inserted, MXene fiber artificial muscles with radially oriented structures and rich hydrogen-bonded networks exhibit excellent actuation performance.

[0019] (3) Radially oriented MXene fiber artificial muscles have the advantages of fast and multiple (thermal, electrical, and optical) stimulus responses. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the preparation process of radially oriented MXene fiber artificial muscle of the present invention. First, Ti3C2T x MXene solution, and then Ti3C2T xMXene and cellulose nanofibers (CNFs) were uniformly mixed and concentrated at high speed to obtain MXene / CNFs spinning ink, which was then assembled by needle wet spinning with an expansion channel, passed through an ethanol coagulation bath, and vacuum dried to obtain radially oriented MXene fiber artificial muscles.

[0021] Figure 2 The macroscopic photos and orientation degree of the radially oriented MXene fiber artificial muscle in Example 1. A, digital photo of a radially oriented MXene fiber artificial muscle over 100 meters long wound on a reel; B, two-dimensional WAXS spectrum of the radially oriented MXene fiber artificial muscle; C, azimuthal curve of the (002) peak of the radially oriented MXene fiber artificial muscle.

[0022] Figure 3 The driving performance of the radially oriented MXene fiber artificial muscle in Example 1. A, digital photo and infrared thermal imaging photo of the reversible contraction drive of the radially oriented MXene fiber artificial muscle under cyclic heating / cooling; B, the stretching stroke and work of the radially oriented MXene fiber artificial muscle with different MXene / CNFs ratios, with an applied load of 0.64 MPa.

[0023] Figure 4 This is a demonstration of the application of the radially oriented MXene fiber artificial muscle in Example 1. Under the stimulation of 808 nm near-infrared light, the radially oriented MXene fiber artificial muscle can repeatedly pull up an artificial prosthesis that is more than 1000 times its own weight for more than 200 times. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. However, the following embodiments are limited to explaining the present invention, and the protection scope of the present invention should include the entire contents of the claims, and through the description of the following embodiments, those skilled in the art can fully implement the entire contents of the claims of the present invention.

[0025] Figure 1 The schematic diagram of the preparation process of the radially oriented MXene fiber artificial muscle of the present invention is shown in FIG. Specifically, Ti3C2T x MXene solution, and then Ti3C2T x MXene and cellulose nanofibers (CNFs) were uniformly mixed and concentrated at high speed to obtain MXene / CNFs spinning ink, which was then assembled by needle wet spinning with an expansion channel, passed through an ethanol coagulation bath, and vacuum dried to obtain radially oriented MXene fiber artificial muscles.

[0026] In the following examples of the present invention, some raw materials and preparation equipment are as follows: Ti3AlC2 MAX (purity: 98%, 400 mesh, Jilin Yiyi Technology Co., Ltd.); Lithium fluoride (purity: 98%, Aladdin); Hydrochloric acid (purity: 36~38%, Sinopharm Chemical Reagent); cellulose nanofibers (NanoFC, average particle size ~5 nm); Ethanol (purity: 99.7%, Beijing Chemical Plant); The orientation degree of radially oriented MXene fiber artificial muscle was tested using a wide-angle X-ray diffractometer (Xenocs Xeuss SAXS / WAXS, Cu-Kα X-ray beam); Thermal imaging photographs of radially oriented MXene fiber artificial muscles contracting and actuated when heated were recorded using an infrared thermal imager (FOTRIC 228s, Shanghai Thermal Imaging Technology Co., Ltd.).

[0027] Example 1 Add 3.2 g of lithium fluoride (LiF) to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, slowly add 2 g of Ti3AlC2 MAX powder and stir in a water bath at 50°C for 30 hours. After the reaction is completed, cool to room temperature, evenly disperse the reaction solution into 6 centrifuge tubes, add deionized water, centrifuge at 3500 rpm for 5 minutes, pour out the supernatant, and repeat this process 8 to 10 times until the pH of the supernatant exceeds 6. Then add deionized water to the above precipitate and shake for 5 minutes, centrifuge at 1500 rpm for 30 minutes, and collect the supernatant. Repeat this process to collect more supernatant until the supernatant is light green. Centrifuge the collected supernatant at 4500 rpm for 20 minutes, collect the precipitate; dilute the precipitate with deionized water to obtain 3 mg / mL Ti3C2T x MXene solution.

[0028] A cellulose nanofiber solution with a concentration of 10 mg / mL was prepared. x MXene solution and cellulose nanofiber solution are mixed evenly, and Ti3C2T xThe mass ratio of MXene and cellulose nanofibers is 5:5. Excess water is removed by high-speed concentration using a centrifuge to obtain a high-concentration MXene / CNFs spinning ink with a total concentration of 30 mg / mL. The MXene / CNFs spinning ink is transferred to a syringe with an expansion channel needle, and then the extrusion speed of the microinjection pump is set to 300 μL / min. When the extruded MXene / CNFs composite nanosheets pass through the expansion channel needle with a narrow side width, the stress of the expansion diffusion will cause the MXene / CNFs composite nanosheets to be arranged perpendicular to the spinning direction. After passing through an ethanol coagulation bath, the MXene fibers are collected on a reel at a speed of 300 μL / min, and the radially oriented MXene fiber artificial muscle (MFAM-II) is obtained after vacuum drying at 40°C for 24 hours. As shown in Figure 2 As shown in the figure, a radially oriented MXene fiber artificial muscle with a length of more than 100 mm was prepared, and its orientation degree f was 0.63.

[0029] Example 2 Add 3.2 g of lithium fluoride (LiF) to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, slowly add 2 g of Ti3AlC2 MAX powder and stir in a water bath at 50°C for 30 hours. After the reaction is completed, cool to room temperature, evenly disperse the reaction solution into 6 centrifuge tubes, add deionized water, centrifuge at 3500 rpm for 5 minutes, pour out the supernatant, and repeat this process 8 to 10 times until the pH of the supernatant exceeds 6. Then add deionized water to the above precipitate and shake for 5 minutes, centrifuge at 1500 rpm for 30 minutes, and collect the supernatant. Repeat this process to collect more supernatant until the supernatant is light green. Centrifuge the collected supernatant at 4500 rpm for 20 minutes, collect the precipitate; dilute the precipitate with deionized water to obtain 3 mg / mL Ti3C2T x MXene solution.

[0030] A cellulose nanofiber solution with a concentration of 10 mg / mL was prepared. x MXene solution and cellulose nanofiber solution are mixed evenly, and Ti3C2T xThe mass ratio of MXene and cellulose nanofibers is 5:5. Excess water is removed by high-speed concentration using a centrifuge to obtain a high-concentration MXene / CNFs spinning ink with a total concentration of 30 mg / mL. The MXene / CNFs spinning ink is transferred to a syringe with an expansion channel needle, and then the extrusion speed of the microinjection pump is set to 300 μL / min. When the extruded MXene / CNFs composite nanosheets pass through the expansion channel needle with a narrow side width, the stress of the expansion diffusion will cause the MXene / CNFs composite nanosheets to be arranged perpendicular to the spinning direction. After passing through an ethanol coagulation bath, the MXene fibers are collected on a reel at a speed of 300 μL / min, and the radially oriented MXene fiber artificial muscle (MFAM-II) is obtained after vacuum drying at 40°C for 24 hours. As shown in Figure 3 As shown in Figure A, the radially oriented MXene fiber artificial muscle can lift a 1 g weight when heated from 25°C to 125°C, and can return to its original state after cooling. Figure 3 As shown in B, the stretching stroke is 21% and the work is 1.1 J g -1 .

[0031] Example 3 Add 3.2 g of lithium fluoride (LiF) to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, slowly add 2 g of Ti3AlC2 MAX powder and stir in a water bath at 50°C for 30 hours. After the reaction is completed, cool to room temperature, evenly disperse the reaction solution into 6 centrifuge tubes, add deionized water, centrifuge at 3500 rpm for 5 minutes, pour out the supernatant, and repeat this process 8 to 10 times until the pH of the supernatant exceeds 6. Then add deionized water to the above precipitate and shake for 5 minutes, centrifuge at 1500 rpm for 30 minutes, and collect the supernatant. Repeat this process to collect more supernatant until the supernatant is light green. Centrifuge the collected supernatant at 4500 rpm for 20 minutes, collect the precipitate; dilute the precipitate with deionized water to obtain 3 mg / mL Ti3C2T x MXene solution.

[0032] A cellulose nanofiber solution with a concentration of 10 mg / mL was prepared. x MXene solution and cellulose nanofiber solution are mixed evenly, and Ti3C2T xThe mass ratio of MXene and cellulose nanofibers is 5:5. Excess water is removed by high-speed concentration using a centrifuge to obtain a high-concentration MXene / CNFs spinning ink with a total concentration of 30 mg / mL. The MXene / CNFs spinning ink is transferred to a syringe with an expansion channel needle, and then the extrusion speed of the microinjection pump is set to 300 μL / min. When the extruded MXene / CNFs composite nanosheets pass through the expansion channel needle with a narrow side width, the stress of the expansion diffusion will cause the MXene / CNFs composite nanosheets to be arranged perpendicular to the spinning direction. After passing through an ethanol coagulation bath, the MXene fibers are collected on a reel at a speed of 300 μL / min, and the radially oriented MXene fiber artificial muscle (MFAM-II) is obtained after vacuum drying at 40°C for 24 hours. As shown in Figure 4 As shown, the radially oriented MXene fiber artificial muscle can repeatedly pull up an artificial prosthesis that is more than 1,000 times its own weight more than 200 times under the stimulation of 808 nm near-infrared light, demonstrating stable photothermal driving performance.

[0033] Example 4 Add 3.2 g of lithium fluoride (LiF) to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, slowly add 2 g of Ti3AlC2 MAX powder and stir in a water bath at 50°C for 30 hours. After the reaction is completed, cool to room temperature, evenly disperse the reaction solution into 6 centrifuge tubes, add deionized water, centrifuge at 3500 rpm for 5 minutes, pour out the supernatant, and repeat this process 8 to 10 times until the pH of the supernatant exceeds 6. Then add deionized water to the above precipitate and shake for 5 minutes, centrifuge at 1500 rpm for 30 minutes, and collect the supernatant. Repeat this process to collect more supernatant until the supernatant is light green. Centrifuge the collected supernatant at 4500 rpm for 20 minutes, collect the precipitate; dilute the precipitate with deionized water to obtain 3 mg / mL Ti3C2T x MXene solution.

[0034] A cellulose nanofiber solution with a concentration of 10 mg / mL was prepared. x MXene solution and cellulose nanofiber solution are mixed evenly, and Ti3C2T xThe mass ratio of MXene and cellulose nanofibers is 7:3. Excess water is removed by high-speed concentration using a centrifuge to obtain a high-concentration MXene / CNFs spinning ink with a total concentration of 30 mg / mL. The MXene / CNFs spinning ink is transferred to a syringe with an expansion channel needle, and then the extrusion speed of the microinjection pump is set to 300 μL / min. When the extruded MXene / CNFs composite nanosheets pass through the expansion channel needle with a narrow side width, the stress of the expansion diffusion will cause the MXene / CNFs composite nanosheets to be arranged perpendicular to the spinning direction. After passing through an ethanol coagulation bath, the MXene fibers are collected on a reel at a speed of 300 μL / min, and the radially oriented MXene fiber artificial muscle (MFAM-I) is obtained after vacuum drying at 40°C for 24 hours. As shown in Figure 3 As shown in Figure A, the radially oriented MXene fiber artificial muscle can lift a 1 g weight when heated from 25°C to 125°C. Figure 3 As shown in B, the stretching stroke is 14% and the work is 0.5 Jg. -1 .

[0035] Example 5 Add 3.2 g of lithium fluoride (LiF) to a polytetrafluoroethylene bottle containing 40 mL of hydrochloric acid (HCl) (9 M) solution. After stirring evenly, slowly add 2 g of Ti3AlC2 MAX powder and stir in a water bath at 50°C for 30 hours. After the reaction is completed, cool to room temperature, evenly disperse the reaction solution into 6 centrifuge tubes, add deionized water, centrifuge at 3500 rpm for 5 minutes, pour out the supernatant, and repeat this process 8 to 10 times until the pH of the supernatant exceeds 6. Then add deionized water to the above precipitate and shake for 5 minutes, centrifuge at 1500 rpm for 30 minutes, and collect the supernatant. Repeat this process to collect more supernatant until the supernatant is light green. Centrifuge the collected supernatant at 4500 rpm for 20 minutes, collect the precipitate; dilute the precipitate with deionized water to obtain 3 mg / mL Ti3C2T x MXene solution.

[0036] A cellulose nanofiber solution with a concentration of 10 mg / mL was prepared. x MXene solution and cellulose nanofiber solution are mixed evenly, and Ti3C2T xThe mass ratio of MXene and cellulose nanofibers is 3:7. Excess water is removed by high-speed concentration using a centrifuge to obtain a high-concentration MXene / CNFs spinning ink with a total concentration of 30 mg / mL. The MXene / CNFs spinning ink is transferred to a syringe with an expansion channel needle, and then the extrusion speed of the microinjection pump is set to 300 μL / min. When the extruded MXene / CNFs composite nanosheets pass through the expansion channel needle with a narrow side width, the stress of the expansion diffusion will cause the MXene / CNFs composite nanosheets to be arranged perpendicular to the spinning direction. After passing through an ethanol coagulation bath, the MXene fibers are collected on a reel at a speed of 300 μL / min, and the radially oriented MXene fiber artificial muscle (MFAM-III) is obtained after vacuum drying at 40°C for 24 hours. As shown in Figure 3 As shown in Figure A, the radially oriented MXene fiber artificial muscle can lift a 1 g weight when heated from 25°C to 125°C. Figure 3 As shown in B, the stretching stroke is 16% and the work is 0.7 J g -1 .

[0037] It should be noted that, according to the above-mentioned embodiments of the present invention, those skilled in the art can fully implement the entire scope of claim 1 and the appendant rights of the present invention, and the implementation process and method are the same as the above-mentioned embodiments; and the parts not elaborated in detail in the present invention belong to the well-known technology in the field.

[0038] The above descriptions are only some specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the art within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing radially oriented MXene fiber artificial muscle, characterized in that: The following steps are involved: Step 1: Prepare Ti3C2T by in-situ hydrofluoric acid etching x MXene solution; Step 2, dispersing the cellulose nanofibers in deionized water, and preparing a uniformly dispersed cellulose nanofiber solution by ultrasonication of a cell disruptor; Step 3: Prepare the Ti3C2T x The MXene solution and the cellulose nanofiber solution prepared in step 2 are uniformly mixed to obtain a MXene / CNFs mixed solution; Step 4, the MXene / CNFs mixed solution prepared in step 3 is concentrated by a centrifuge at high speed to remove excess water, thereby obtaining a MXene / CNFs spinning ink; Step 5, transferring the MXene / CNFs spinning ink prepared in step 4 into a syringe with an expansion channel needle, and extruding the MXene / CNFs spinning ink into an ethanol coagulation bath through a micro-syringe pump; Step 6: Slowly collect the MXene fibers assembled by wet spinning in step 5 onto a reel and vacuum dry them to obtain radially oriented MXene fiber artificial muscles.

2. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In step 1, Ti3C2T x The preparation process of MXene is as follows: the raw material Ti3AlC2 MAX powder is added to a solution containing hydrochloric acid and lithium fluoride, and the mixture is stirred under heating conditions for reaction; the mixture after the complete reaction is centrifuged, the upper liquid is poured off, and the mixture is repeatedly washed with deionized water until the pH value exceeds 6; the precipitate after centrifugation is dispersed in deionized water, and Ti3C2T is obtained by repeated shaking and centrifugation. x MXene solution.

3. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In the step 2, the concentration of the cellulose nanofibers in the cellulose nanofiber solution is 5 mg / mL to 20 mg / mL.

4. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In the step 3, the mass ratio of MXene to CNFs in the MXene / CNFs mixed solution is 7:3 to 3:

7.

5. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In step 4, the concentration of the MXene / CNFs spinning ink is 20 mg / mL to 50 mg / mL.

6. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In the step 5, the diameter of the spinning needle is 210 μm, the expansion transition diameter is 510 μm, and the microinjection pump extrude the MXene / CNFs spinning ink into the ethanol coagulation bath at 100 μL / min~400 μL / min.

7. The method for preparing a radially oriented MXene fiber artificial muscle according to claim 1, characterized in that: In step 6, the collection speed of the wet-spun assembled MXene fibers is 100 μL / min~400 μL / min.

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