Polycarbonate-based conductive elastomer based on mxene doping and preparation method and application thereof

Abstract

The application provides a polycarbonate-based conductive elastomer doped with MXene and a preparation method and application thereof. The conductive elastomer comprises aliphatic polycarbonate (APC), polydeep eutectic solvent (PDES) and MXene, the mass ratio of the aliphatic polycarbonate and the polydeep eutectic solvent is 1:0.5-3, and the addition amount of the MXene is 1-5 wt% of the total mass of the APC and the PDES. The conductive elastomer obtained by the application has the advantages of simple preparation process, environmental friendliness, no need for high temperature and high pressure, and the like. The comprehensive performance of mechanical strength, electrical sensitivity, biocompatibility and degradability, photothermal response and antibacterial performance is realized. The material structure is stable, and the conductive elastomer is suitable for fields of flexible sensors, electronic skin, health monitoring, photothermal therapy and intelligent antibacterial materials and the like.

Description

Technical Field

[0001] This application belongs to the field of flexible functional materials technology, and in particular relates to an MXene-doped polycarbonate conductive elastomer, its preparation method and application. Background Technology

[0002] In recent years, with the rapid development of flexible electronics, smart wearable devices, and artificial intelligence sensing systems, higher demands have been placed on novel conductive materials with high flexibility, high sensitivity, excellent response performance, and multifunctional integration. Traditional rigid sensors can no longer meet the comprehensive requirements of wearable devices, miniaturized biomedical devices, and smart skin for flexibility, stretchability, reusability, and multifunctionality. Therefore, developing a conductive elastomer material that combines good mechanical properties, conductive properties, and other additional functions (such as antibacterial and photothermal responses) has become one of the important research directions in the fields of polymer materials and flexible electronics.

[0003] Conductive elastomers are composite materials that are made by doping a flexible polymer matrix with conductive fillers (such as metal nanoparticles, carbon-based nanomaterials, conductive polymers, etc.) to give it a certain conductivity. They not only retain the softness and stretchability of elastomers, but also introduce conductive pathways, so that they can respond to external mechanical stimuli and are widely used in flexible sensors, electronic skin, artificial muscles, intelligent robots and other scenarios. However, the current research and development of conductive elastomers faces the following technical challenges: (1) It is difficult to balance conductivity and stretchability: Generally speaking, increasing the content of conductive fillers helps to improve the conductivity of composite materials, but too much filler will make the material brittle and lose its elasticity, thereby weakening its stretchability and mechanical stability, limiting its application in wearable devices. (2) Insufficient multifunctional integration: Many conductive elastomers at present only have conductivity and a certain degree of flexibility, lacking functions such as photothermal response, antibacterial, and programmable sensing, which is not conducive to their promotion in composite application scenarios such as biomedicine and smart health. (3) Poor interface stability: Due to the poor interfacial compatibility between inorganic conductive fillers and organic polymer matrix, phase separation or filler shedding is likely to occur during strain, resulting in damage to the conductive network and subsequent performance degradation. (4) Complex structural construction methods and high difficulty in industrialization: The construction of many existing conductive elastomers relies on high-energy-consuming, high-polluting or low-efficiency preparation methods, which cannot meet the needs of large-scale industrial production. Summary of the Invention

[0004] This application is made in view of the above-mentioned issues, and its purpose is to provide a multifunctional conductive elastomer based on MXene doping, its preparation method and application. The elastomer material not only has good flexibility and mechanical strength, but also has high electrical sensitivity, excellent photothermal response capability and efficient antibacterial properties, and is suitable for smart wearables, flexible sensors, biomedical patches and other fields.

[0005] To achieve the above objectives, this application provides an MXene-doped multifunctional conductive elastomer that combines excellent mechanical properties, electrical response characteristics, biocompatibility, biodegradability, and photothermal antibacterial function.

[0006] The first aspect of this application provides a polycarbonate-based conductive elastomer based on MXene doping, comprising aliphatic polycarbonate (APC), polydegradable eutectic solvent (PDES), and MXene, wherein the mass ratio of aliphatic polycarbonate to polydegradable eutectic solvent is 1:0.5-3, and the amount of MXene added is 1-5 wt% of the total mass of APC and PDES.

[0007] In any embodiment, the aliphatic polycarbonate is prepared from the following raw materials: polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, and 5-methyl-5-carboxylic acid trimethylene carbonate in a molar ratio of 1:50:25-50:1 to stannous octoate.

[0008] In any embodiment, the polyeutectic solvent is prepared from the following raw materials: the molar ratio of choline chloride to acrylic acid is 1:1-2.

[0009] A second aspect of this application also provides a method for preparing a polycarbonate-based conductive elastomer based on MXene doping, comprising the following steps:

[0010] 1) Synthetic aliphatic polycarbonates;

[0011] 2) Synthesize polyeutectic solvents;

[0012] 3) Premixing and dissolving: Weigh APC and PDES, add them to N,N-dimethylformamide at a mass ratio of 1:0.5-3, and stir magnetically at 50-100℃ until a homogeneous and transparent solution is formed;

[0013] 4) Doping and dispersion of MXene: Weigh MXene powder and add it to the mixture of APC and PDES. Use ultrasound to treat for 30-45 minutes to make MXene fully and uniformly dispersed in the system.

[0014] 5) Curing and molding: Pour the above mixed solution into a polytetrafluoroethylene mold, place it in a vacuum drying oven, and dry it at 70-100℃ to remove the solvent and obtain a conductive elastomer containing MXene.

[0015] In any embodiment, the synthesis of the aliphatic polycarbonate (APC) is as follows: polyethylene glycol monomethyl ether mPEG113, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, 5-methyl-5-carboxylic acid trimethylene carbonate, and stannous octoate are weighed in a molar ratio of 1:50:25-50:1; polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, and 5-methyl-5-carboxylic acid trimethylene carbonate are placed in a polymerization tube, and a stannous octoate toluene solution is added; the tube is evacuated and then filled with argon gas, repeated several times, and then heated and sealed; the polymerization tube is placed in an oil bath at 110-150℃, and after all the substances in the tube have melted, the polymerization tube is repeatedly shaken to ensure uniform mixing; after reacting at a constant temperature for 10-15 h, the polymerization tube is removed and naturally cooled to room temperature; the product is dissolved in tetrahydrofuran, precipitated with methanol, and dried under vacuum to obtain a colorless and transparent product.

[0016] In any embodiment, the synthesis of the polyeutectic solvent (PDES) is as follows: choline chloride and acrylic acid in a molar ratio of 1:1-2 are weighed and added to a flask. The reaction system is heated and stirred in a constant temperature oil bath at 50-70℃ for 3-5 hours until the system becomes a homogeneous and transparent liquid, thus obtaining the polyeutectic solvent (DES). 10 mL of DES is taken, and 0.5% (by mass) of photoinitiator 2959 is added. The mixture is placed in a polytetrafluoroethylene mold, and the mold is placed under a 365 nm UV lamp with a power of 550W at a distance of 10 cm to initiate polymerization. The irradiation time is 2 minutes, resulting in PDES gel.

[0017] In any embodiment, the choline chloride is vacuum dried at 60°C for 4 h, and the acrylic acid is dried through a molecular sieve.

[0018] In any embodiment, the dissolution temperature in step 3) is 70°C.

[0019] In any embodiment, 1-5 wt% of MXene powder, comprising APC and PDES, is added in step 4).

[0020] In any embodiment, the reaction temperature in step 1) is controlled at 130 °C and the reaction time is controlled at 12 h.

[0021] In any implementation, the mass ratio of APC / PDES in step 3) is 1:0.5-3.

[0022] In any implementation, the doping mass of MXene in step 4) is 3-5 wt%.

[0023] A third aspect of this application also provides an application of MXene-doped polycarbonate conductive elastomers, in which the above materials are used in flexible sensors, electronic skin, health monitoring, photothermal therapy, and smart antibacterial materials.

[0024] Features and beneficial effects of the present invention:

[0025] Structural features and performance characteristics of the conductive elastomer of this invention:

[0026] 1) Stable interface structure: The abundant polar groups (such as -OH, =O, -F) on the surface of MXene form multiple hydrogen bonds with the carboxyl groups in APC or PDES, establishing a stable non-covalent network and improving the structural stability and swelling inhibition ability of the elastomer.

[0027] 2) Enhanced mechanical properties: With the increase of MXene doping ratio, the fracture stress of the material increases from 175.4 kPa to 363.2 kPa, the elastic modulus is improved, and it is suitable for high toughness deformation scenarios.

[0028] 3) Excellent sensing sensitivity: The material of this invention has high response sensitivity (GF up to 6.02) in the strain range of 1%-5%, and is suitable for micro-deformation recognition scenarios such as wearable motion detection and human-computer interaction interfaces.

[0029] 4) Significant photothermal conversion capability: MXene in the material rapidly converts 808 nm near-infrared light into heat energy through local surface plasmon resonance. The surface temperature rises to 87.5℃ within 110 s of irradiation, providing a foundation for subsequent antibacterial and thermal response applications.

[0030] 5) Photothermal antibacterial function: After being irradiated with near-infrared light, the material of this invention has an antibacterial rate of 99.93% against Gram-positive bacteria (Staphylococcus aureus) and 99.80% against Gram-negative bacteria (Escherichia coli), achieving efficient sterilization without the need for additional antibacterial agents.

[0031] Compared with the prior art, the multifunctional polycarbonate conductive elastomer based on MXene doping of the present invention has the following beneficial effects:

[0032] 1) The preparation process is simple and environmentally friendly, requiring no high temperature or high pressure.

[0033] 2) Excellent overall performance, achieving multiple optimizations in mechanical strength, electrical sensitivity, biocompatibility and biodegradability, photothermal response and antibacterial properties;

[0034] 3) The structure is stable, and the doped MXene is evenly dispersed, avoiding agglomeration and sedimentation, thus ensuring the long-term usability of the material;

[0035] 4) It has a wide range of applications and can be extended to fields such as flexible sensors, electronic skin, health monitoring, photothermal therapy and smart antibacterial materials.

[0036] This invention not only provides a novel conductive elastomer material, but also establishes a functional material design and preparation pathway with high versatility, low cost, and high performance, which has significant theoretical value and application prospects. Attached Figure Description

[0037] Figure 1 This application presents a synthetic route for MXene-doped polycarbonate-based conductive elastomers.

[0038] Figure 2 The infrared spectra of the MXene-doped conductive elastomers in Examples 1-3 of this application are shown.

[0039] Figure 3 These are SEM images of MXene-doped conductive elastomers from Examples 1-3 of this application;

[0040] Figure 4 The stress-strain curves of MXene-doped conductive elastomers in Examples 1-3 of this application are shown.

[0041] Figure 5 The diagram shows a comparison of the specification factors of the DPM3 sample in Example 3 of this application under different strain ranges (a) and a diagram of the relative resistance-time response (b).

[0042] Figure 6 This is an electrocardiogram (ECG) image collected after the DPM3 sample was attached to the wrist in Example 3 of this application.

[0043] Figure 7 These are surface thermal images of the DPM3 sample in Example 3 of this application at different time points.

[0044] Figure 8 This image shows the antibacterial effect of sample 3DPM3 in Example 3 of this application under photothermal action, where a is the Staphylococcus aureus blank group, b is the Staphylococcus aureus control group, c is the Staphylococcus aureus experimental group, d is the Escherichia coli blank group, e is the Escherichia coli control group, and f is the Escherichia coli experimental group. Detailed Implementation

[0045] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the MXene-doped polycarbonate conductive elastomer and its preparation method thereof. However, unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of essentially the same structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for a full understanding of this application by those skilled in the art and are not intended to limit the subject matter of the claims.

[0046] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0047] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0048] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0049] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0050] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0051] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0052] Based on the mechanical properties, electrical response characteristics, biocompatibility, biodegradability, and photothermal antibacterial function of the materials in this application, they are suitable for the requirements of the wearable sensor field. Researchers have attempted to introduce two-dimensional materials with high specific surface area, good conductivity, and interfacial activity as conductive fillers. MXene is a material composed of two-dimensional transition metal carbides, nitrides, or carbonitrides, and has the following characteristics: 1) Excellent conductivity: Due to its two-dimensional structure and metallic conduction band characteristics, MXene exhibits near-metallic conductivity, making it an excellent charge carrier transport medium; 2) High specific surface area and surface functional groups: The surface of MXene sheets contains a large number of polar functional groups (hydroxyl, carbonyl, fluorine, etc.), which are beneficial for forming non-covalent interactions such as hydrogen bonds with the polymer matrix, thereby improving the interfacial bonding strength; 3) Excellent photothermal conversion capability: MXene materials have strong absorption in the near-infrared region and can achieve efficient photothermal conversion through localized surface plasmon resonance.

[0053] Aliphatic polycarbonates (APCs) have attracted much attention due to their excellent biocompatibility, biodegradability, and controllable mechanical properties. Aliphatic polycarbonates are typically prepared by ring-opening polymerization of cyclic carbonate monomers. This polymerization method offers advantages such as mild reaction conditions and controllable product structure. Aliphatic polycarbonates possess many superior properties, making them promising for broad applications in materials science. On the one hand, their good biocompatibility allows for applications in biomedicine; on the other hand, aliphatic polycarbonates exhibit a certain degree of flexibility and processability.

[0054] As a novel type of green ionic liquid, deep eutectic solvents (DES) not only possess advantages such as wide availability, low cost, ease of preparation, antibacterial properties, and biodegradability, but also exhibit high design freedom, wide temperature tolerance, and good ionic conductivity and chemical stability, overcoming the shortcomings of hydrogels (which are prone to freezing at low temperatures and volatilization at high temperatures) and conventional ionic liquids (which are costly and have certain toxicity). The core characteristic of DES is the construction of a dynamic hydrogen bond network through hydrogen bond acceptors (such as polyols and carboxylic acids) and hydrogen bond donors (such as quaternary ammonium salts). However, because DES also plays a toughening role in gels, the mechanical properties of most DES-based ionic gels are relatively weak. This application utilizes EDS polymers (PDES, an elastomer) to improve mechanical properties, making the construction of ionic gels with good mechanical properties a feasible approach. Furthermore, the addition of MXene enhances the electrical conductivity and sensing performance of the elastomer, addresses the issue of PDES reducing ion transport capacity, and also provides photothermal effects.

[0055] Through extensive research and experimental verification, the inventors of this application have constructed a multifunctional conductive elastomer with good tensile properties, high sensitivity response, biocompatibility, and photothermal antibacterial properties by dissolving APC and PDES in a suitable solvent, thoroughly mixing them, and then doping them with different amounts of MXene using an ultrasonic dispersion method. The formation of this conductive elastomer achieves a stable cross-linked network through abundant multiple hydrogen bonds and other interactions among APC, PDES, and MXene, realizing the uniform distribution of MXene in the elastomer system and the stability of non-covalent interfaces. This significantly improves the material's mechanical, electrical, and photothermal properties, and has important application prospects in personal motion monitoring, intelligent healthcare, and human-computer interaction.

[0056] In one embodiment of this application, a polycarbonate-based conductive elastomer based on MXene doping is proposed, comprising aliphatic polycarbonate, polyeutectic solvent and MXene, wherein the mass ratio of aliphatic polycarbonate to polyeutectic solvent is 1:0.5-3, and the amount of MXene added is 1-5 wt% of the total mass of APC and PDES.

[0057] In some embodiments, the aliphatic polycarbonate is prepared from the following raw materials: polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, and 5-methyl-5-carboxylic acid trimethylene carbonate in a molar ratio of 1:50:25-50:1 to stannous octoate.

[0058] To obtain polycarbonates with different mechanical properties.

[0059] In some embodiments, the polyeutectic solvent is prepared from the following raw materials: choline chloride and acrylic acid in a molar ratio of 1:1-2.

[0060] Choline chloride (ChCl) and malonic acid (AA) can be used to prepare a eutectic solvent, which consists of a hydrogen bond donor (ChCl) and a hydrogen bond acceptor (AA) in a specific ratio. The electrical and mechanical properties of the polyeutectic solvent can be optimized by adjusting the monomer ratio. Within this range, PDES exhibits the best electrical and mechanical properties.

[0061] In one embodiment of this application, a method for preparing a polycarbonate-based conductive elastomer based on MXene doping is proposed, comprising the following steps:

[0062] 1) Synthetic aliphatic polycarbonates;

[0063] 2) Synthesize polyeutectic solvents;

[0064] 3) Premixing and dissolving: Weigh APC and PDES and add them to N,N-dimethylformamide at a mass ratio of 1:0.5-3. Stir magnetically at 50-100℃ until a homogeneous and transparent solution is formed. N,N-dimethylformamide (DMF) is used as a solvent. Adding DMF can make the components mix evenly. Finally, remove DMF under vacuum to obtain the elastomer.

[0065] Too low a PDES content affects conductivity, while too high a content affects the uniformity of mixing, which in turn affects mechanical properties, conductivity, and so on.

[0066] 4) Doping and dispersion of MXene: Weigh MXene powder and add it to the mixture of APC and PDES. Use ultrasound to treat for 30-45 minutes to make MXene fully and uniformly dispersed in the system; MXene is a nano powder.

[0067] 5) Curing and Molding: Pour the above mixed solution into a polytetrafluoroethylene mold, place it in a vacuum drying oven, and dry it at 70-100℃ to remove the solvent, obtaining a conductive elastomer containing MXene. High drying temperatures can cause air bubbles in the elastomer film, thus affecting the material properties.

[0068] In some embodiments, the synthesis of the aliphatic polycarbonate (APC) is as follows: Polyethylene glycol monomethyl ether mPEG113, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, 5-methyl-5-carboxylic acid trimethylene carbonate, and stannous octoate are weighed in a molar ratio of 1:50:25-50:1. The polyethylene glycol monomethyl ether mPEG113, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, and 5-methyl-5-carboxylic acid trimethylene carbonate are placed in a polymerization tube, and 250 µL of stannous octoate toluene solution is added. The tube is then evacuated and purged with argon gas, repeated several times, and then heated and sealed. The polymerization tube is placed in an oil bath at 110-150°C, and after all the substances inside have melted, the tube is repeatedly shaken to ensure uniform mixing. After reacting at a constant temperature for 10-15 h, the polymerization tube is removed and allowed to cool naturally to room temperature. The product is dissolved in tetrahydrofuran, precipitated with methanol, and dried under vacuum to obtain a colorless and transparent product.

[0069] In some embodiments, the synthesis of the polyeutectic solvent (PDES) is as follows: choline chloride and acrylic acid in a molar ratio of 1:1-2 are added to a flask, and the reaction system is heated and stirred in a constant temperature oil bath at 50-70°C for 3-5 hours until the system becomes a homogeneous and transparent liquid, thus obtaining the polyeutectic solvent (DES); a certain amount of DES is taken, and 0.5% of the DES mass of photoinitiator 2959 is added, which is placed in a polytetrafluoroethylene mold. The mold is placed under a 365 nm UV lamp with a power of 550W at a distance of 10 cm to initiate polymerization. The irradiation time is 2 minutes, thus obtaining PDES gel.

[0070] In some embodiments, the choline chloride is vacuum dried at 60°C for 4 h, and the acrylic acid is dried through a molecular sieve.

[0071] In some embodiments, the dissolution temperature in step 3) is 70°C.

[0072] Solution formation is slow below 70°C, and energy consumption and safety hazards exist above 70°C. This application aims to improve the preparation quality and efficiency of the product through optimization.

[0073] In some embodiments, step 4) involves adding 1-5 wt% of MXene powder, which is the total amount of APC and PDES.

[0074] MXene (Ti3C2T) XThe powder is formed by etching the MAX phase with hydrogen fluoride. Tx indicates the presence of surface functional groups, which can be hydrogen, oxygen, hydroxyl or other functional groups.

[0075] When the amount of MXene added is too small, the electrical conductivity, sensing sensitivity and photothermal performance of the corresponding material are not ideal; when the amount added exceeds 5%, the MXene will not be evenly dispersed in the elastomer and will agglomerate.

[0076] In some embodiments, step 1) involves controlling the reaction temperature at 130 °C and the reaction time at 12 h. These are considered optimal preparation conditions, resulting in high preparation efficiency and good product quality.

[0077] In some implementations, the mass ratio of APC / PDES in step 3) is 1:0.5-3.

[0078] In some implementations, the doping mass of MXene in step 4) is 3-5 wt%.

[0079] Example

[0080] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0081] Example 1

[0082] A polycarbonate conductive elastomer based on MXene doping and its preparation method, comprising the following steps:

[0083] 1) Synthesis of aliphatic polycarbonate (APC)

[0084] Weigh 0.95 g (0.5 mmol) of polyethylene glycol monomethyl ether (mPEG). 113 6.25 g (25 mmol) of 5-methyl-5-benzyloxycarbonyltrimethylene carbonate (prepared in the laboratory) and 2.0 g (12.5 mmol) of 5-methyl-5-carboxytrimethylene carbonate (prepared in the laboratory) were placed in a polymerization tube, and 350 µL of stannous octoate toluene solution (0.2062 mol / L) was added. The mixture was evacuated and then purged with argon gas, repeated three times, and the polymerization tube was heated and sealed. The polymerization tube was placed in an oil bath at 130 °C, and after all the contents had melted, the tube was repeatedly shaken to ensure homogeneous mixing. After reacting at a constant temperature for 12 h, the polymerization tube was removed and allowed to cool naturally to room temperature. The product was dissolved in tetrahydrofuran, precipitated with methanol, and dried under vacuum to obtain a colorless and transparent product.

[0085] 2) Synthesis of polydegradable eutectic solvent (PDES)

[0086] 13.96 g (0.1 mol) of dried choline chloride and 12.96 g (0.18 mmol) of acrylic acid were weighed and added to a flask. The reaction system was heated and stirred in a 60°C oil bath for 4 h until the system became a homogeneous and transparent liquid, yielding a deep eutectic solvent (DES). 10 mL of DES was taken, and 0.5% (by mass) of photoinitiator 2959 was added. The mixture was placed in a polytetrafluoroethylene mold, and the mold was placed at a distance of 10 cm under a 550 W 365 nm UV lamp to initiate polymerization for 2 minutes, yielding PDES gel.

[0087] 3) Premixing and dissolving

[0088] Weigh APC and PDES and add them to 10 mL of N,N-dimethylformamide at a mass ratio of 1:2. Stir magnetically at 70°C until a transparent solution is formed.

[0089] 4) Curing and molding

[0090] Weigh 1 wt% MXene (Ti3C2T) X The powder was added to a mixture of APC and PDES, and ultrasonically treated for 30 minutes to ensure that MXene was fully and uniformly dispersed in the system. The solution was then poured into a polytetrafluoroethylene mold and vacuum dried at 80°C to obtain a conductive elastomer containing MXene.

[0091] Example 2

[0092] Compared with Example 1, the difference lies in step 4) curing and molding: weigh 2 wt% MXene (Ti3C2T) x The powder was added to a mixture of APC and PDES, and ultrasonically treated for 30 minutes to ensure that MXene was fully and uniformly dispersed in the system. The solution was then poured into a polytetrafluoroethylene mold and vacuum dried at 80°C to obtain a conductive elastomer containing MXene.

[0093] Example 3

[0094] Compared with Example 1, the difference lies in step 4) curing and molding: weigh 3 wt% MXene (Ti3C2T) x The powder was added to a mixture of APC and PDES, and ultrasonically treated for 30 minutes to ensure that MXene was fully and uniformly dispersed in the system. The solution was then poured into a polytetrafluoroethylene mold and vacuum dried at 80°C to obtain a conductive elastomer containing MXene.

[0095] Example 4

[0096] Compared with Example 1, the difference lies in step 4) curing and molding: weigh 4 wt% MXene (Ti3C2T) x The powder was added to a mixture of APC and PDES, and ultrasonically treated for 30 minutes to ensure that MXene was fully and uniformly dispersed in the system. The solution was then poured into a polytetrafluoroethylene mold and vacuum dried at 80°C to obtain a conductive elastomer containing MXene.

[0097] Example 5

[0098] Compared with Example 1, the difference lies in step 4) curing and molding: weigh 5 wt% MXene (Ti3C2T) x The powder was added to a mixture of APC and PDES, and ultrasonically treated for 30 minutes to ensure that MXene was fully and uniformly dispersed in the system. The solution was then poured into a polytetrafluoroethylene mold and vacuum dried at 80°C to obtain a conductive elastomer containing MXene.

[0099] The following instruments and characterization methods were used to analyze the examples:

[0100] (1) Infrared spectroscopy: FT-IR tests were performed using a Spectrumho Fourier transform infrared spectrometer from PerkinElmerg, USA. The wavenumber range of the absorption spectrum scan was 4000-500 cm⁻¹. -1 .

[0101] (2) Scanning electron microscopy: Scanning electron microscopy tests were performed using a HITACHI SU8010 scanning electron microscope. After the samples were sputtered with gold, the surface morphology of the conductive elastomer was observed and recorded under an accelerating voltage of 5 kV and a current of 10 μA.

[0102] (3) Mechanical property testing: The mechanical properties were tested using a CMT6103 electronic universal testing machine from MTECH Industrial Systems. The samples were prepared using a dumbbell-shaped polytetrafluoroethylene mold of national standard type I. The tensile rate during the test was 50 mm / min. -1 By plotting stress as the Y-axis and strain as the X-axis, the stress-strain curve of the material is obtained.

[0103] (4) Sensing performance test: The test was conducted using the CHI760E electrochemical workstation from Shanghai Chenhua Instrument Co., Ltd. When testing the conductivity and sensing performance of the elastomer sample, the elastomer was prepared into a size of 30 mm × 15 mm × 3 mm using a polytetrafluoroethylene mold. Both ends were fixed with double-headed alligator clip electrodes, and the other end of the alligator clip electrodes was connected to the electrochemical workstation. The it mode was selected to record the strain current change of the elastomer, and the strain sensing signal was obtained through the relative resistance change (…). Resistance ( ) The following formula is used to calculate .

[0104] (1)

[0105] In the formula The voltage applied to the electrochemical workstation The current in the elastic body.

[0106] The change in relative resistance is calculated using the following formula.

[0107] (2)

[0108] In the formula The resistance value of the elastic body when strain is applied. This represents the initial resistance value of the elastomer.

[0109] Flexible sensors assembled from conductive elastomers typically have their sensitivity determined by a gauge factor ( ). The normative factor can be calculated using the following formula, which measures the normative factor.

[0110] (3)

[0111] In the formula This represents the change in relative resistance. The strain applied to an elastic body includes the applied force, etc.

[0112] (5) Photothermal performance test: Using the HW808AD1000-34F 808nm near-infrared light emitter (1 W cm⁻¹) from Shenzhen Infrared Laser Technology Co., Ltd. -2 Conductive elastomer samples with different MXene doping contents (sample size: 20 mm × 20 mm × 15 mm) were irradiated. The temperature after the irradiation was started was recorded in real time using an HD46E15 handheld thermal imager from Huajingkang Optoelectronics Co., Ltd.

[0113] The chemical reagents used in the embodiments of this invention were provided by Sinopharm Chemical Reagent Co., Ltd.; the invention will be described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of application of the invention. Various modifications or alterations to the invention and other equivalent forms are also within the scope limited by the appended claims.

[0114] Figure 2 The infrared spectra of the MXene-doped conductive elastomers described in Examples 1-3 are shown below. DPM1, DPM2, and DPM3 correspond to the samples obtained in Examples 1-3, respectively. The infrared spectra are at 3400 cm⁻¹. -1The absorption peak at 1735 cm⁻¹ is attributed to the stretching vibration of OH. -1 The absorption peak at 1608 cm⁻¹ is attributed to the stretching vibration peak of C=O. -1 The peak at 1340 cm⁻¹ belongs to the benzene ring skeletal vibration. -1 The peak at this point is attributed to the CN stretching vibration of the quaternary ammonium salt in choline chloride. With increasing doping content of MXene materials, the absorption peak of OH increases from 3381 cm⁻¹. -1 The redshift reached 3371 cm. -1 Furthermore, the peak position of the stretching vibration peak of C=O also increased from 1732 cm⁻¹. -1 Moved to 1724cm -1 This confirms that hydrogen bonds are formed between the surface groups of MXene materials and the carbonyl groups in the elastomer system.

[0115] Figure 3 The images shown are SEM images of the MXene-doped conductive elastomers described in Examples 1-3, where a, b, and c correspond to the SEM images of the conductive elastomers in Examples 1, 2, and 3, respectively. As the MXene doping content increases, the number of lamellar materials on the surface of the conductive elastomer increases, and they still exhibit a relatively uniformly embedded state on the surface of the conductive elastomer without aggregation, indicating that the MXene material has good dispersion in the conductive elastomer.

[0116] Figure 4 The figures show the stress-strain curves of the MXene-doped conductive elastomers described in Examples 1-3. As the MXene doping concentration increased from 1 wt% to 3 wt%, the crosslinking density of the physical crosslinking network further increased, and the strength of the conductive elastomer also increased accordingly, with the fracture stress increasing from 175.35 kPa to 363.22 kPa. DPM1, DPM2, and DPM3 represent the samples obtained in Examples 1, 2, and 3, respectively.

[0117] Figure 5 The diagram shows the comparison of the gauge factor and relative resistance-time response of the DPM3 sample described in Example 3 under different strain ranges. Within the range of 0-300%, the conductive elastomer can produce an effective and repeatable response to strain, and the gauge factor increases from 3.72 to 6.02 as the strain range expands, indicating its high sensitivity.

[0118] Figure 6 The electrocardiogram (ECG) recorded by attaching the DPM3 electrode patch described in Example 3 to the wrist of the test subject showed regular signal output and good sensitivity.

[0119] Figure 7The images show the surface thermal images of the DPM3 sample described in Example 3 at different time points. As the illumination time increases, the surface temperature of the conductive elastomer gradually increases. After 110 seconds of near-infrared light irradiation, the surface temperature of the DPM3 conductive elastomer increased from 25.3℃ to 87.5℃.

[0120] Figure 8 This is a diagram showing the antibacterial effect of the DPM3 sample described in Example 3 under photothermal action. Figure 8 The colony count of Staphylococcus aureus in the control group was 1411. Figure 8 The colony count of Staphylococcus aureus in the control group was 1435. Figure 8 The colony count of Staphylococcus aureus in the c group was 1, and the antibacterial activity of conductive elastomer DPM3 against Staphylococcus aureus was 99.93%. Figure 8 The colony count of *E. coli* in the blank control group was 10^33. Figure 8 The colony count of *E. coli* in the control group was 10¹⁴. Figure 8 The *E. coli* colony count in the experimental group was 2, and the conductive elastomer showed 99.80% antibacterial activity against *E. coli*. The MXene-doped conductive elastomer DPM3 exhibited strong photothermal inhibition against the growth of both *Staphylococcus aureus* and *E. coli*. The blank group received no treatment; the control group was simply placed in a 12-well plate with the bacterial dilution under the same illumination conditions as the experimental group; the experimental group had the bacterial dilution placed on a pre-prepared DPM3 conductive elastomer in a 12-well plate, and the illumination conditions were 808 nm near-infrared light (1 W / m²). -2 Under these conditions, the diameter of the light spot on the material is fixed at 10 mm, and the light is irradiated for 10 min.

[0121] As can be seen from the above description of specific embodiments, the MXene-doped conductive elastomer provided by the present invention has a simple preparation process and excellent material properties. It exhibits significant advantages in mechanical strength, sensing response, photothermal conversion and antibacterial properties, and has important application prospects in the fields of human motion monitoring, health monitoring, and rehabilitation therapy.

[0122] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A polycarbonate-based conductive elastomer based on MXene doping, characterized in that, The mixture comprises aliphatic polycarbonate, a polyeutectic solvent, and MXene. The mass ratio of the aliphatic polycarbonate to the polyeutectic solvent is 1:0.5-3, and the amount of MXene added is 1-5 wt% of the total mass of the aliphatic polycarbonate and the polyeutectic solvent. The resulting conductive elastomer forms a stable cross-linked network through abundant multiple hydrogen bond interactions between the aliphatic polycarbonate, the polyeutectic solvent, and MXene, achieving uniform distribution of MXene in the elastomer system and non-covalent interface stability. The raw materials for preparing the aliphatic polycarbonate include polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, 5-methyl-5-carboxytrimethylene carbonate, and stannous octoate in a molar ratio of 1:50:25-50:

1.

2. The conductive elastomer according to claim 1, characterized in that, The polyeutectic solvent is prepared from the following raw materials: the molar ratio of choline chloride to acrylic acid is 1:1-2.

3. A method for preparing MXene-doped polycarbonate conductive elastomers, characterized in that, Includes the following steps: 1) Synthesis of aliphatic polycarbonate: Weigh polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate, 5-methyl-5-carboxylic acid trimethylene carbonate and stannous octoate in a molar ratio of 1:50:25-50:1; place polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyltrimethylene carbonate and 5-methyl-5-carboxylic acid trimethylene carbonate in a polymerization tube, add stannous octoate toluene solution; evacuate and then fill with argon gas, repeat several times, heat and seal the polymerization tube; place the polymerization tube in an oil bath at 110-150℃, and after all the substances in the tube have melted, repeatedly shake the polymerization tube to mix the system evenly; after reacting at a constant temperature for 10-15 h, remove the polymerization tube and cool it naturally to room temperature, dissolve the product with tetrahydrofuran, precipitate with methanol, and vacuum dry to obtain a colorless and transparent product; 2) Synthesize polyeutectic solvents; 3) Premixing and dissolving: Weigh aliphatic polycarbonate and polyeutectic solvent, add them to N,N-dimethylformamide at a mass ratio of 1:0.5-3, and stir magnetically at 50-100℃ until a homogeneous and transparent solution is formed; 4) Doping and dispersion of MXene: Weigh 1-5 wt% of MXene powder of aliphatic polycarbonate and polyeutectic solvent, add it to the mixture of aliphatic polycarbonate and polyeutectic solvent, and use ultrasonic treatment for 30-45 minutes to make MXene fully and uniformly dispersed in the system. 5) Curing and molding: Pour the mixed solution obtained in step 4) into a polytetrafluoroethylene mold, place it in a vacuum drying oven, and dry it at 70-100℃ to remove the solvent, thereby obtaining a conductive elastomer containing MXene. The formed conductive elastomer forms a stable cross-linking network through the rich multiple hydrogen bond interactions between aliphatic polycarbonate, polyeutectic solvent and MXene, thereby achieving uniform distribution of MXene in the elastomer system and non-covalent interface stability.

4. The preparation method according to claim 3, characterized in that, The synthesis of the deep eutectic solvent: Choline chloride and acrylic acid in a molar ratio of 1:1-2 were weighed and added to a flask. The reaction system was heated and stirred in a constant temperature oil bath at 50-70℃ for 3-5 hours until the system became a homogeneous and transparent liquid, thus obtaining the deep eutectic solvent DES; 10 mL of DES was taken, and 0.5% of the DES mass of photoinitiator was added. The mixture was placed in a polytetrafluoroethylene mold, and the mold was placed under a 365 nm UV lamp with a power of 550W at a distance of 10 cm to initiate polymerization. The illumination time was 2 minutes, thus obtaining the deep eutectic solvent gel.

5. The preparation method according to claim 3, characterized in that, The dissolution temperature in step 3) is 70℃.

6. The preparation method according to claim 3, characterized in that, In step 1), the reaction temperature is controlled at 130℃ and the reaction time is controlled at 12h.

7. The preparation method according to claim 3, characterized in that, In step 4), the doping mass of MXene is 3-5 wt%.

8. The application of MXene-doped polycarbonate conductive elastomers, characterized in that, The application of conductive elastomers according to any one of claims 1-2 or conductive elastomers prepared by the method of any one of claims 3-7 in the field of smart antibacterial materials.

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