Preparation method and application of high-stability flexible electronic fabric

Abstract

The invention discloses a preparation method and application of a high-stability flexible electronic fabric, and belongs to the technical field of functional textile materials and flexible electronics. The invention aims to solve the problems that MXene is easy to oxidize, easy to fall off under repeated deformation and poor in long-term stability when being used as a conductive layer of a fabric. The preparation method comprises the following steps: modifying a fabric by using polydopamine, obtaining an MXene conductive fabric by using a dip-coating method, and obtaining an MXene / PPy electronic fabric of which the conductive layer is controllable in morphology by using a low-temperature oscillation adsorption method and a low-temperature in-situ polymerization method; the combination of polydimethylsiloxane and the micro-nano rough conductive layer is regulated and controlled through a spraying method, and the flexible electronic fabric is obtained. The flexible electronic fabric provided by the invention has good structural stability, flexibility and biocompatibility and excellent electrical properties. The flexible electronic fabric can resist damage of mechanical external force to the conductive layer, and still keeps good electrical stability in a high-humidity environment for a long time, and the flexible electronic fabric has wide application prospects in the aspects of electro / photo-thermal physiotherapy, wearable monitoring and electromagnetic protection.

Description

Technical Field

[0001] This invention belongs to the field of functional textile materials and flexible electronics technology, specifically, it relates to a method for preparing and applying a highly stable flexible electronic fabric. Background Technology

[0002] Flexible electronic fabrics, based on textile fibers, possess natural softness, breathability, and stretchability. As functional wearable devices, flexible electronic fabrics can be bent, folded, and even wrinkled like ordinary cloth, perfectly conforming to the irregular curves of the human body without the foreign body sensation and pressure associated with traditional rigid devices, greatly enhancing the user experience. Electrical stability is crucial for the effective operation of flexible electronic fabrics.

[0003] MXene, due to its excellent conductivity, photothermal properties, and mechanical properties, has become a preferred conductive material for flexible electronic fabrics, showing great potential in electro / photothermal therapy, wearable monitoring, and electromagnetic protective clothing. However, the use of MXene as a conductive layer in electronic fabrics is mostly achieved through methods such as dip coating, spraying, and step-by-step deposition, as seen in: a flexible intelligent stress sensor based on MXene electronic fabric composites and its preparation method (CN113091964B); a method for forming and dyeing conductive synthetic fiber fabrics (CN116289180B); a multifunctional coating with flame retardancy, antibacterial properties, and electromagnetic shielding, and its preparation and application (CN119553492A); and a method for preparing multifunctional aramid composite fabrics and its application (CN118563560A). In these electronic fabrics based on MXene conductive materials, it is difficult to achieve a strong interfacial bond between MXene and the fabric surface. Under repeated deformation, the MXene sheets are prone to detachment, affecting the electrical stability of the electronic fabric. A flexible wearable thermoelectric fabric and its preparation method (CN118461308 A) employs a composite conductive layer, but it does not completely solve the problems of easy oxidation and poor water stability of the conductive layer on the fabric, limiting the long-term stable use of the electronic fabric. A paper (Fabric-based superhydrophobic MXene@ polypyrrole heater with superior dual-driving energy conversion, Journal of Colloid and Interface Science 629 (2023), 2022 09-05) discloses that an in-situ polymerization of MXene and Py is carried out to construct a hydrophobic coating. While the hydrophobic coating provides some protection for the MXene conductive layer, this single protective layer is insufficient to guarantee the long-term electrical stability of the flexible electronic fabric. Therefore, developing a highly stable flexible electronic fabric that can provide multi-layer protection for the MXene conductive material, preventing mechanical damage and resisting outdoor environmental interference is of great significance. Summary of the Invention

[0004] This invention aims to solve the problems of easy oxidation, easy shedding under repeated deformation, and poor long-term stability when using MXene as the conductive layer of fabric, and provides a method for preparing and applying a highly stable flexible electronic fabric.

[0005] To address the aforementioned technical problems, the present invention adopts the following technical solution: This invention coats MXene nanosheets onto the fiber surface to form an initial conductive layer. Then, PPy nanoparticles are uniformly coated onto the surface of the MXene conductive layer to construct a dense PPy conductive layer, protecting the MXene from mechanical damage and reducing oxidation caused by the external environment. Simultaneously, polydimethylsiloxane, combined with the granular PPy conductive layer, constructs a low surface energy fiber interface, resulting in a flexible electronic fabric with superhydrophobic properties. This allows the flexible electronic fabric to resist damage to the conductive layer from liquid environments such as acids, alkalis, and salts. The dual protective layer constructed from PPy and polydimethylsiloxane enables the flexible electronic fabric to maintain good electrical stability under long-term high humidity environments. The flexible electronic fabric prepared by this invention exhibits good structural stability, flexibility, biocompatibility, and excellent electrical properties. By constructing a double protective layer of PPy and polydimethylsiloxane, the flexible electronic fabric can resist the damage to the conductive layer by mechanical external forces. Even after being subjected to mechanical external forces and long-term exposure to high humidity, the flexible electronic fabric still maintains good conductivity and exhibits excellent conductivity stability, demonstrating that the flexible electronic fabric has broad application prospects in electro / photothermal therapy, wearable monitoring and electromagnetic protection.

[0006] The purpose of this invention is to provide a method for preparing highly stable flexible electronic fabrics. Includes the following steps: Step 1: Immerse the fabric in an ethanol solution for a certain period of time, rinse with deionized water, and dry. Step 2: Then put it into a dopamine solution, adjust the pH to 8.0-8.5, react it at a certain temperature for a certain time, rinse it with deionized water, and let it air dry naturally. Step 3: Then immerse it in the MXene dispersion for a period of time, and then dry it; Step 4: Repeat step 3 at least once; Step 5: Add Py monomer to deionized water and sonicate until homogeneous. Adjust the pH to 1-4 to obtain a Py monomer solution. Then, under low-temperature shaking, immerse the fabric treated in Step 4 into the Py monomer solution until the Py molecules are fully and uniformly adsorbed onto the surface of the MXene sheets. Then, add an oxidant and adjust the shaking speed to allow the Py monomer to polymerize in situ under low-temperature conditions. After that, wash thoroughly with low-temperature deionized water and vacuum dry. Step 6: Then spray polydimethylsiloxane to obtain the flexible electronic fabric, which has superhydrophobic properties.

[0007] Further specifying, in step 1, the fabric is cotton fabric, nylon fabric, or ketone-ammonia fabric; and is woven using a knitting process.

[0008] Further specifying, in step 1, the concentration of the ethanol solution is 30 vol% ~ 60 vol.

[0009] Further specifying, in step 1, the soaking time is 30 min to 60 min.

[0010] Further specifying, in step 1, drying is carried out at 50 ℃ ~ 70 ℃; the drying is carried out in a vacuum drying oven.

[0011] To further specify, in step 2, the pH is adjusted using Tris-HCl buffer.

[0012] Further specifying the reaction conditions, in step 2, the concentration of dopamine is 0.6 wt% ~ 1.2 wt%; the reaction is carried out at 25 ℃ ~ 40 ℃ for 12 h ~ 24 h. Under these reaction conditions, the polydopamine prepared can coat the fiber surface, increasing the surface roughness and providing more adhesion sites for the MXene material. Furthermore, polydopamine contains a large number of hydroxyl groups, which can improve the hydrophilicity of the fabric, thus facilitating the adhesion of the MXene material.

[0013] Further specified, the concentration of MXene dispersion is 5 mg / mL ~ 25 mg / mL; the immersion time is 30 min.

[0014] Further specifying, in step 5, the concentration of Py monomer is 5 mg / mL to 15 mg / mL; Further specifying, in step 5, the oxidant is ammonium persulfate or ferric chloride hexahydrate, the molar ratio of Py monomer to ammonium persulfate is 1:(1.5~2.2), and the molar ratio of Py monomer to ferric chloride hexahydrate is 1:(1.6~2.4).

[0015] Further specifying, in step 5, the pH is adjusted using p-toluenesulfonic acid or salicylic acid.

[0016] Further specifying, in step 5, the shaking speed is 100 ~ 200 rpm, and the in-situ polymerization is carried out at a low temperature of 0 ~ 5℃ for 3h ~ 5h; the in-situ polymerization is carried out in a frozen water bath shaker.

[0017] Further specifying, in step 6, the mass fraction of the polydimethylsiloxane solution is 0.5 wt% ~ 1.5 wt%, and the solvent used to prepare the polydimethylsiloxane solution is ethyl acetate, cyclohexane, or n-hexane.

[0018] The present invention also provides flexible electronic fabrics prepared by any of the methods described above.

[0019] Furthermore, the use of the flexible electronic fabric of the present invention is also provided, with potential applications in wearable monitoring.

[0020] The invention also provides applications of the flexible electronic fabric, with potential applications in electro / photothermal therapy.

[0021] The invention also provides applications for the flexible electronic fabric, with potential applications in electromagnetic protection.

[0022] This invention involves impregnating the fabric with an ethanol solution to remove residual oil from the fiber surface. Polydopamine is then used to modify the fabric to increase surface roughness, providing better adhesion sites for MXene materials and establishing hydrogen bonds with MXene to promote greater MXene loading on the fiber surface. A dip-coating process is then used to uniformly load the MXene material onto the fiber surface, forming an initial MXene conductive coating. The fabric with the MXene conductive coating is pre-immersed in a low-temperature, shaken Py monomer solution for a period of time to ensure the Py monomers are fully and uniformly adsorbed onto the surface of the MXene conductive layer. Under low-temperature conditions, the Py monomers undergo in-situ self-polymerization under the action of an oxidant. By controlling the shaking speed of the shaker, the resulting PPy nanoparticles uniformly coat the surface of the MXene conductive layer, constructing a dense PPy conductive layer, resulting in a composite MXene / PPy electronic fabric. PPy, as a conductive layer, not only possesses good stability and biocompatibility but also protects the MXene conductive layer from mechanical detachment. Meanwhile, the PPy conductive layer utilizes its self-constructed nanoparticle morphology combined with polydimethylsiloxane to build a low surface energy fiber interface, endowing the flexible electronic fabric with excellent hydrophobic properties, achieving a maximum water contact angle of 156.5°. Controlling the thickness of the polydimethylsiloxane film on the PPy conductive layer surface is crucial in this process. If the polydimethylsiloxane film is too thin and not fully bonded to the PPy conductive layer, the hydrophobic effect of the flexible electronic fabric will be weak. If the polydimethylsiloxane film is too thick, it will reduce the surface roughness of the PPy conductive layer, thus reducing the hydrophobic effect of the flexible electronic fabric. Flexible electronic fabrics with superhydrophobic capabilities can not only resist mechanical damage to the conductive layer but also resist damage from water, acid, and alkali solutions. Furthermore, they can maintain excellent conductivity stability in long-term high-humidity environments, improving their stability and lifespan as flexible electronic fabrics.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) In this invention, MXene material is used to construct the initial conductive core layer, and PPy material is used to construct the composite conductive shell layer. MXene material exhibits excellent conductivity, and PPy material exhibits good conductive stability. Through a pre-adsorption-in-situ self-polymerization process, a dense PPy conductive layer is formed, which can uniformly coat the surface of the MXene conductive layer to prepare MXene / PPy electronic fabric. The MXene / PPy electronic fabric exhibits significant electrical stability. After repeated stretching, friction, and torsion tests, the conductivity of the MXene / PPy electronic fabric did not decrease significantly. This is attributed to the good protective effect of the PPy conductive layer on the MXene conductive layer, as well as the strong bonding interface formed by the self-polymerization of the PPy conductive layer.

[0024] (2) This invention constructs an MXene / PPy conductive layer. By controlling the self-polymerization conditions of Py, a PPy conductive layer with controllable nanomorphology is obtained. Combined with polydimethylsiloxane, a low surface energy fiber interface is constructed, endowing the flexible electronic fabric with superhydrophobic properties. The flexible electronic fabric exhibits excellent wettability to various solutions (acids, alkalis, salts, cola, coffee, and milk). Mechanical tests on the flexible electronic fabric show that it maintains excellent superhydrophobic properties even after repeated stretching, friction, and torsion cycle tests. Furthermore, the flexible electronic fabric also maintains excellent superhydrophobic properties after being impregnated with acid and alkali solutions. Due to the excellent superhydrophobicity of the flexible electronic fabric and the protective effect of the PPy layer on MXene, the flexible electronic fabric can maintain excellent conductivity stability in long-term high-humidity environments, which helps it maintain stable performance in complex working environments.

[0025] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, the accompanying drawings are for reference and illustration only and are not intended to limit the invention. Attached Figure Description

[0026] Figure 1 This is a SEM image of MXene loaded on the fiber surface in Embodiment 1 of the present invention; Figure 2 This is a SEM image of PPy coated on an MXene conductive layer according to Embodiment 1 of the present invention; Figure 3 This is a surface SEM image of the PPy conductive layer bonded to polydimethylsiloxane in Embodiment 1 of the present invention; Figure 4 This is a diagram showing the wettability of the flexible electronic fabric of Embodiment 1 of the present invention to various droplets; Figure 5 This is a graph showing the trend of water contact angle change of the flexible electronic fabric in Embodiment 1 of the present invention after stretching and ultrasonic treatment; Figure 6 This is a graph showing the trend of contact angle change of the flexible electronic fabric of Embodiment 1 of the present invention after different acid impregnation times; Figure 7 This is a graph showing the change trend of conductivity of the flexible electronic fabric in Embodiment 1 of the present invention after stretching and washing. Figure 8 This is a graph showing the change trend of conductivity of the flexible electronic fabric of Embodiment 1 of the present invention after being treated with different alkali impregnation times; Figure 9 These are the photothermal performance data and infrared thermal imaging images of the flexible electronic fabric of Embodiment 1 of the present invention; Figure 10 These are the electrothermal performance data and infrared thermal imaging images of the flexible electronic fabric of Embodiment 1 of the present invention; Figure 11 This is a graph showing the change in electromagnetic shielding efficiency of the flexible electronic fabric in Embodiment 1 of the present invention; Figure 12 This is a strain sensing performance data diagram of the flexible electronic fabric in Embodiment 1 of the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, while not limiting the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0028] The MXene dispersion used in the following examples was prepared according to the following steps: 4 g of LiF, 62 mL of HCl (12M), and 18 mL of deionized water were added to a polytetrafluoroethylene beaker, which was then placed in a water bath at 35°C with a magnetic stirrer at 400 rpm for 30 min. Then, 4 g of Ti3AlC2 powder was slowly added to the mixture, and the reaction was continued at 35°C for 24 h. The resulting Ti3C2T... x The product was washed with deionized water and centrifuged at 5000 rpm for 5 min each time until the solution pH was close to neutral. Then, using deionized water as an intercalating agent, the mixture was ultrasonicated with a 500 W ultrasonic cleaner for 1 h. Finally, the mixture was centrifuged at 5000 rpm for 15 min to obtain the MXene dispersion.

[0029] Example 1: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, remove the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature. Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 2 using p-toluenesulfonic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 180 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ferric chloride hexahydrate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ferric chloride hexahydrate is 1:2. The shaking speed of the shaker is 180 rpm at 0 ℃, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids. Step 6: Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0030] In this embodiment, MXene is loaded onto the fiber surface through step 3, and its SEM image is shown below. Figure 1 As shown, by Figure 1 As can be seen, the MXene conductive material is uniformly coated on the surface of the fiber, forming the initial MXene conductive layer. PPy is coated onto the MXene conductive layer in step 5, and its SEM image is shown below. Figure 2 As shown, by Figure 2A tight coating of PPy was observed, forming a granular PPy conductive layer. PPy, as a conductive layer, not only exhibits good stability and biocompatibility but also protects the MXene conductive layer from mechanical detachment. The surface SEM image of the PPy conductive layer bonded to polydimethylsiloxane is shown below. Figure 3 As shown, by Figure 3 It was observed that the PPy conductive layer, utilizing its rough nanoparticle morphology combined with polydimethylsiloxane, constructs a low surface energy fiber interface, endowing the flexible electronic fabric with outstanding hydrophobic properties. The wettability of the flexible electronic fabric to various droplets is shown in the figure below. Figure 4 As shown, by Figure 4 It can be seen that flexible electronic fabrics exhibit excellent wettability to solutions such as acids, alkalis, salts, cola, coffee, and milk. The trend of water contact angle changes in flexible electronic fabrics after stretching and ultrasonic treatment is shown in the figure below. Figure 5 As shown, by Figure 5 It was observed that the water contact angle of the flexible electronic fabric decreased only slightly, while Figure 6 The graph shows the contact angle change trend of flexible electronic fabric after different acid impregnation times. It observes that the flexible electronic fabric still maintains good hydrophobic properties, which provides a solid foundation for its ability to maintain good electrical performance in various complex environments. The graph also shows the conductivity change trend of the flexible electronic fabric after stretching and washing treatments. Figure 7 As shown, by Figure 7 The observation of only a slight decrease in conductivity indicates a very strong interfacial bond between the conductive layer MXene / PPy and the fiber surface, and also demonstrates the good protective effect of the PPy conductive layer on the MXene conductive layer. The conductivity trends of the flexible electronic fabric after different alkali impregnation times are shown in the figure below. Figure 8 As shown, by Figure 8 The observed slight change in conductivity indicates that the flexible electronic fabric maintains excellent electrical stability even in complex liquid environments, laying a solid foundation for its long-term stable use. The photothermal performance data and infrared thermal imaging images of the flexible electronic fabric are shown below. Figure 9 As shown, by Figure 9 It can be observed at 100 mw / cm 2 Under light intensity, the surface temperature of the flexible electronic fabric reached 77 ℃. After friction, washing, and bending treatments, the surface temperature of the flexible electronic fabric did not decrease significantly, demonstrating good photothermal stability and durability. Furthermore, infrared thermal imaging revealed a rapid photothermal heating rate, showcasing its potential application as a photothermal textile in photothermal therapy. The electrothermal performance data of the flexible electronic fabric are as follows: Figure 10 As shown, by Figure 10It is evident that flexible electronic fabrics possess excellent electrothermal heating capabilities and electrothermal stability, attributed to the superior conductivity and outstanding conductivity stability of the MXene / PPy composite conductive layer. The electromagnetic shielding efficiency of flexible electronic fabrics is as follows: Figure 11 As shown, by Figure 11 It can be seen that flexible electronic fabrics, as electromagnetic shielding textiles, have an electromagnetic shielding efficiency far higher than the commercial standard (20 dB), and after mechanical external force testing, the electromagnetic shielding efficiency does not show a significant downward trend, indicating that flexible electronic fabrics have good electromagnetic shielding stability. Figure 12 This is a graph showing the strain sensing performance data of a flexible electronic fabric, from... Figure 12 It is known that flexible electronic fabrics, as sensing elements of strain sensors, exhibit fast response (60 ms) and recovery (70 ms), and have broad application prospects in wearable motion monitoring.

[0031] Example 2: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, take out the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature. Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 3 using p-toluenesulfonic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 30 min at 0 ℃ and a shaking speed of 160 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ferric chloride hexahydrate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ferric chloride hexahydrate is 1:2. The polymerization time is 4 h at 0 ℃ and a shaking speed of 160 rpm to obtain a composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids. Step 6: Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0032] Example 3: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the cotton fabric in an ethanol solution to remove grease residue from the surface of the cotton fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the cotton fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the cotton fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, remove the modified cotton fabric, rinse it with deionized water to remove residues, and air dry it at room temperature.

[0033] Step 3: Immerse the polydopamine-modified cotton fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a cotton fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 2 using p-toluenesulfonic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded cotton fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 150 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ferric chloride hexahydrate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ferric chloride hexahydrate is 1:2. The shaking speed of the shaker is 150 rpm at 0 ℃, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids.

[0034] Step 6: Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0035] Example 4: The difference between this example and Example 3 is that the fabric substrate is ketone-ammonia fabric. The remaining processes and parameter settings are the same as in Example 3.

[0036] Example 5: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, remove the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature.

[0037] Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 3 using salicylic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 150 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ferric chloride hexahydrate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ferric chloride hexahydrate is 1:2. The polymerization time is 3 h at 0 ℃ and a shaking speed of 150 rpm to obtain a composite MXene / PPy electronic fabric. Then, wash thoroughly with 5 ℃ deionized water to quickly remove residual oxidants and acids.

[0038] Step 6: Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0039] Example 6: The difference between this example and Example 5 is that the nylon fabric loaded with MXene is immersed in a low-temperature agitated Py monomer solution for 30 minutes. The remaining processes and parameter settings are the same as in Example 5.

[0040] Example 7: The difference between this example and Example 5 is that the molar ratio of Py monomer to ferric chloride hexahydrate is 1:1.6. The remaining process and parameter settings are the same as in Example 5.

[0041] Example 8: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, remove the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature.

[0042] Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 3 using p-toluenesulfonic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 170 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ammonium persulfate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ammonium persulfate is 1:1.8. The shaking speed of the shaker is 170 rpm at 0 ℃, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids.

[0043] Step 6: Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0044] Example 9: The difference between this example and Example 8 is that the fabric substrate is cotton fabric, and the other processes and parameter settings are the same as in Example 8.

[0045] Example 10: The difference between this example and Example 8 is that the polymerization time is 3 hours, while the rest of the process and parameter settings are the same as in Example 8.

[0046] Example 11: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, take out the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature. Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 2 using salicylic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 120 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ammonium persulfate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ammonium persulfate is 1:1.8. The shaking speed of the shaker is 120 rpm at 0 ℃, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids.

[0047] Step 6: Spray a 1 wt% polydimethylsiloxane solution (ethyl acetate) onto the surface of the MXene / PPy electronic fabric for 40 s to obtain a superhydrophobic flexible electronic fabric.

[0048] Example 12: The difference between this example and Example 11 is that the nylon fabric loaded with MXene is immersed in the Py monomer solution for 30 minutes, and the rest of the process and parameter settings are the same as in Example 11.

[0049] Example 13: The preparation method of a highly stable flexible electronic fabric in this example is carried out according to the following steps: Step 1: Immerse the nylon fabric in an ethanol solution to remove grease residue from the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying treatment. The temperature of the drying oven is set to 50 ℃. Step 2: Place the nylon fabric treated in Step 1 into a 1.0 wt% dopamine solution, adjust the pH to 8.5 using Tris-HCl buffer, set the reaction temperature to 30 ℃, and the reaction time to 24 h. After that, take out the modified nylon fabric, rinse it with deionized water to remove residues, and air dry it at room temperature. Step 3: Immerse the polydopamine-modified nylon fabric in 15 mg / mL MXene dispersion. After a period of time, remove the fabric and place it in a vacuum drying oven for drying. Step 4: Repeat step 3 at least once to obtain a nylon fabric uniformly loaded with MXene conductive material; Step 5: Add 1g of Py monomer to 100 mL of deionized water and sonicate until homogeneous. Adjust the pH of the solution to 3 using salicylic acid to obtain a Py monomer solution with a concentration of 10 mg / mL. Transfer the Py monomer solution to a shaker and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 160 rpm. To ensure that the Py molecules are fully adsorbed onto the surface of the MXene sheets, ammonium persulfate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ammonium persulfate is 1:1.8. The shaking speed of the shaker is 160 rpm at 0 ℃, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, wash thoroughly with deionized water at 5 ℃ to quickly remove residual oxidants and acids. Step 6: Using a spraying process, a 1.5 wt% polydimethylsiloxane solution with hexane as the solvent is sprayed onto the surface of the MXene / PPy electronic fabric for 30 s to obtain a superhydrophobic flexible electronic fabric.

[0050] Comparative Example 1: The conditions involved in the preparation of the MXene electronic fabric are the same as in Example 1. The difference from Example 1 is that the conductive layer of the MXene electronic fabric in Comparative Example 1 is not coated with PPy material. The specific preparation process is as follows: (1) Immerse the nylon fabric in an ethanol solution to remove the grease residue on the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying. The temperature of the drying oven is set to 50 ℃. (2) The nylon fabric treated in step (1) was placed in a 1.0 wt% dopamine solution, the pH was adjusted to 8.5 using Tris-HCl buffer, the reaction temperature was 30 ℃, the reaction time was 24 h, and then the modified nylon fabric was taken out, rinsed with deionized water to remove residues, and air-dried at room temperature.

[0051] (3) The polydopamine-modified nylon fabric was immersed in 15 mg / mL MXene dispersion. After a period of time, the fabric was taken out and placed in a vacuum drying oven for drying. The above immersion step was repeated once to obtain a nylon fabric uniformly loaded with MXene conductive material. (4) Using a spraying process, a 1 wt% polydimethylsiloxane solution with ethyl acetate as the solvent is sprayed onto the surface of the MXene electronic fabric for 40 s to obtain a hydrophobic flexible electronic fabric.

[0052] Comparative Example 2: The conditions involved in the preparation of the flexible electronic fabric are the same as in Example 1. The difference between Example 1 and Example 2 is that the flexible electronic fabric in Comparative Example 2 was not modified with polydimethylsiloxane. The specific preparation process is as follows: (1) Immerse the nylon fabric in an ethanol solution to remove the grease residue on the surface of the nylon fabric. The volume concentration of the ethanol solution is 40 vol%, and the immersion time is 40 min. Then rinse the surface of the nylon fabric with deionized water and put it into a vacuum drying oven for drying. The temperature of the drying oven is set to 50 ℃. (2) The nylon fabric treated in step (1) was placed in a 1.0 wt% dopamine solution, the pH was adjusted to 8.5 using Tris-HCl buffer, the reaction temperature was 30 ℃, the reaction time was 24 h, and then the modified nylon fabric was taken out, rinsed with deionized water to remove residues, and air-dried at room temperature.

[0053] (3) The polydopamine-modified nylon fabric was immersed in 15 mg / mL MXene dispersion. After a period of time, the fabric was taken out and placed in a vacuum drying oven for drying. The above immersion step was repeated once to obtain a nylon fabric uniformly loaded with MXene conductive material. (4) Prepare a 10 mg / mL Py monomer solution, adjust the pH of the solution to 2 using p-toluenesulfonic acid, transfer the Py monomer solution to a shaker, and immerse the MXene-loaded nylon fabric in the Py monomer solution for 60 min at 0 ℃ and a shaking speed of 180 rpm. In order to fully adsorb the Py molecules onto the surface of the MXene sheets, ferric chloride hexahydrate solution is then slowly added dropwise to the Py monomer solution. The molar ratio of Py monomer to ferric chloride hexahydrate is 1:2. At 0 ℃, the shaking speed of the shaker is 180 rpm, and the polymerization time is 4 h to obtain the composite MXene / PPy electronic fabric. Then, it is thoroughly washed with 5 ℃ deionized water to quickly remove residual oxidants and acids.

[0054] Table 1. Water contact angle test results of electronic fabrics prepared in Examples 1-13 and Comparative Examples 1-2.

[0055] Table 2. Conductivity test results of electronic fabrics prepared in Examples 1-13 and Comparative Examples 1-2.

[0056] Table 3. Conductivity test results of electronic fabrics prepared in Examples 1-13 and Comparative Examples 1-2.

[0057] As shown in Table 1, the water contact angles of the flexible electronic fabrics prepared in Examples 1 to 13 ranged from 154.5° to 156.5°. After stretching, ultrasonic vibration, and acid impregnation, the water contact angles of the flexible electronic fabrics decreased, but they still maintained good superhydrophobicity. Comparative Example 1 is an MXene electronic fabric, which shows a lower water contact angle than the flexible electronic fabric with MXene / PPy as the conductive layer. This is because PPy, as the conductive layer, has a higher surface roughness than the MXene conductive layer. Its combination with polydimethylsiloxane helps to further reduce the surface energy of the conductive fibers and increase the hydrophobicity of the electronic fabric. At the same time, in Comparative Example 1, it can be found that the water contact angle of the MXene electronic fabric fluctuated relatively much after stretching and ultrasonic vibration. This is mainly because the MXene conductive layer is not as stable as the PPy conductive layer. Comparative Example 2 is the MXene / PPy electronic fabric without polydimethylsiloxane coating, which has a water contact angle of 140.4°. This is attributed to the hydrophobic properties of the PPy material itself. In addition, after stretching, ultrasonic vibration and acid impregnation, the water contact angle of the MXene / PPy electronic fabric also showed a decreasing trend.

[0058] Table 2 shows that the conductivity of the flexible electronic fabrics prepared in Examples 1-13 ranges from 203.3 to 284.3 S / m. After stretching, washing, and alkali immersion, the conductivity of the flexible electronic fabrics only slightly decreases. This is attributed to the strong interfacial bonding between the PPy conductive layer and MXene, protecting the MXene conductive layer from detachment, and the excellent superhydrophobic interface protecting the MXene / PPy conductive layer. Therefore, the flexible electronic fabrics exhibit excellent conductivity stability. Comparative Example 1 in Table 2 is an MXene electronic fabric. After stretching and ultrasonic vibration, the conductivity of the MXene electronic fabric decreased significantly, due to the lack of protection from the PPy conductive layer for the MXene material. Comparative Example 2 in Table 2 is an MXene / PPy electronic fabric without polydimethylsiloxane coating. After immersion in an alkaline solution, the conductivity decreased significantly, again due to the lack of protection from the superhydrophobic interface constructed by polydimethylsiloxane for the MXene / PPy conductive layer. Therefore, Tables 1 and 2 show that the PPy conductive layer combined with the superhydrophobic interface is crucial to the conductivity stability of flexible electronic fabrics with MXene / PPy as the conductive layer, and also demonstrate that flexible electronic fabrics have broad application prospects in electro / photothermal therapy, wearable monitoring and electromagnetic protection.

[0059] Table 3 shows that the conductivity of the flexible electronic fabrics prepared in Examples 1-13 ranged from 205.3 to 283.6 S / m. Under 80% relative humidity for 30, 60, and 90 days respectively, the conductivity of the flexible electronic fabrics only showed a slight decrease. This is attributed to the protective effect of the PPy conductive layer on the MXene conductive layer, and the excellent superhydrophobic interface protecting the MXene / PPy conductive layer, thus endowing the flexible electronic fabric with excellent conductive stability. Comparative Example 1 in Table 3 is an MXene electronic fabric. Under 80% relative humidity for 30, 60, and 90 days respectively, a significant decrease in conductivity was observed. This is due to the lack of a PPy conductive layer protecting the MXene material, and the lack of a superhydrophobic interface protecting the MXene material. Comparative Example 2 in Table 3 shows an MXene / PPy electronic fabric without polydimethylsiloxane coating. Under 80% relative humidity for 30, 60, and 90 days, a significant decrease in conductivity was observed. This is attributed to the protective effect of the superhydrophobic interface constructed without polydimethylsiloxane on the MXene / PPy conductive layer. Therefore, Tables 1, 2, and 3 demonstrate that the PPy conductive layer combined with the superhydrophobic interface is crucial for the conductivity stability of flexible electronic fabrics with MXene / PPy as the conductive layer. This also showcases the broad application prospects of flexible electronic fabrics in electro / photothermal therapy, wearable monitoring, and electromagnetic protection.

[0060] The specific embodiments of the present invention have been described in detail above. It should be noted that the present invention is not limited to the specific embodiments described above. Various modifications or alterations can be made by those skilled in the art without departing from the scope of protection defined by the claims, and all such modifications or alterations fall within the scope of the present invention.

Claims

1. A method for preparing a high-stable flexible electronic fabric, characterized in that, The method comprises the following steps: Step 1, the fabric is immersed in an ethanol solution for a certain period of time, rinsed with deionized water, and dried; Step 2, then put into a dopamine solution, adjust the pH to 8.0-8.5, react at a certain temperature for a certain period of time, rinse with deionized water, and air dry; Step 3, then immerse in MXene dispersion liquid for a period of time, and dry; Step 4, repeat step 3 at least once; Step 5, add Py monomer into deionized water and ultrasonically mix until uniform, adjust the pH to 1-4 to obtain a Py monomer solution, then immerse the fabric treated in step 4 into the Py monomer solution under low-temperature shaking, wait for the Py molecules to be fully adsorbed on the surface of the MXene sheet, then add an oxidizing agent, control the shaking speed, and allow the Py monomer to polymerize in situ under low-temperature conditions, and then wash with low-temperature deionized water and vacuum dry; Step 6, then spray polydimethylsiloxane, and the flexible electronic fabric is obtained; In step 1, the concentration of the ethanol solution is 30 vol%-60 vol%; in step 2, the concentration of dopamine is 0.6 wt%-1.2 wt%; in step 3, the concentration of the MXene dispersion liquid is 5 mg / mL-25 mg / mL; in step 5, the concentration of the Py monomer is 5 mg / mL-15 mg / mL; and in step 6, the mass fraction of the polydimethylsiloxane solution is 0.5 wt%-1.5 wt%.

2. The method of claim 1, wherein, In step 1, the fabric is a cotton fabric, a nylon fabric, or a ketone-ammonia fabric.

3. The method of claim 1, wherein, In step 1, the immersion time is 30 min-60 min, and the drying is performed at 50 ℃-70 ℃.

4. The method of claim 1, wherein, In step 2, the reaction is performed at 25 ℃-40 ℃ for 12 h-24 h.

5. The method of claim 1, wherein, In step 5, the oxidizing agent is ammonium persulfate or ferric chloride hexahydrate, the molar ratio of the Py monomer to ammonium persulfate is 1:(1.5-2.2), and the molar ratio of the Py monomer to ferric chloride hexahydrate is 1:(1.6-2.4); in step 5, the pH is adjusted with p-toluenesulfonic acid or salicylic acid; the shaking speed is 100 rpm-200 rpm, and the in-situ polymerization is performed at low temperature for 3 h-5 h.

6. The method of claim 1, wherein, The solvent for preparing the polydimethylsiloxane solution is ethyl acetate, cyclohexane, or n-hexane.

7. A flexible electronic fabric prepared by the method of any one of claims 1-6.

8. The flexible electronic fabric prepared by the method of any one of claims 1-6 for use in electrical / optical thermal physiotherapy applications.

9. The flexible electronic fabric prepared by the method of any one of claims 1-6 for use in wearable monitoring applications.

10. The flexible electronic fabric prepared by the method of any one of claims 1-6 for use in electromagnetic shielding applications.

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