Preparation method and application of lipoic acid-glycine electronic material with self-repairing function

Abstract

The invention belongs to the technical field of flexible electronic materials, and particularly relates to a preparation method and application of a lipoic acid-glycine electronic material with a self-repairing function, and the preparation method comprises the following steps: step 1, dissolving a carboxyl-containing organic compound in an anhydrous organic solvent to start a ring-opening reaction; 2, introducing an ionic liquid, and carrying out dynamic polymerization under the protection of nitrogen to construct a prepolymer with a disulfide bond network; 3, amino compounds are added in a gradient mode to achieve collaborative assembly of molecular chains; 4, forming a film substrate through a gradient curing process (vacuum drying-low-temperature orientation-humidity annealing); 5, activating a functional interface in a specific swelling medium; and step 6, integrating to an intelligent sensor to serve as a flexible sensing unit. Through a dynamic covalence strategy, the mechanical strength, self-repairing efficiency and conductive stability of the material are effectively balanced by utilizing the ion synergistic effect of carboxyl / amino compounds and the dynamic recombination characteristic of disulfide bonds, and the material is particularly suitable for the fields of wearable medical monitoring and electronic skin.

Description

Technical Field

[0001] The present invention belongs to, but is not limited to, the technical field of flexible electronic materials, and particularly relates to a preparation method and application of a lipoic acid-glycine electronic material with self-healing function. Background Art

[0002] With the rapid development of the Internet of Things and intelligent devices, intelligent electronic sensors are increasingly widely used in fields such as environmental monitoring, healthcare, and industrial control. However, traditional electronic sensors are prone to mechanical damage or chemical corrosion during use, resulting in performance degradation or failure, which limits their service life and application scope. To solve this problem, researchers are committed to developing intelligent sensor materials with self-healing functions to extend the service life of sensors and improve their reliability.

[0003] In recent years, polymers with dynamic disulfide bonds have been widely used in repairable sensors due to their self-healing properties at room temperature. However, the presence of terminal biradicals leads to poor stability, which limits their performance in practical applications. To overcome this problem, researchers have begun to explore new self-healing material systems. Glycine (GLY) can effectively quench thiol radicals due to its good reactivity towards nucleophilic protons, thus preparing polymer materials with excellent self-healing properties.

[0004] Lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl), as materials for intelligent electronic sensors, have advantages such as high conductivity, good stability, tunability, environmental friendliness, excellent selectivity, and low power consumption. By reasonably designing the composition and processing method of the materials, high sensitivity, long life, and wide applicability of the sensors can be achieved. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a preparation method of a repairable intelligent electronic sensor based on lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl). This method quenches thiol radicals by introducing glycine (GLY) to prepare a self-healing polymer material (poly TA-(EMIM-Cl)-GLY), and uses its excellent self-healing properties, high conductivity, and good stability to prepare an intelligent electronic sensor with long life and high sensitivity.

[0006] The present invention is realized as follows. A preparation method of a repairable intelligent electronic sensor based on lipoic acid and 1-ethyl-tripropylimidazolium chloride includes the following steps: Step 1, dissolve an organic compound containing a carboxyl group in an anhydrous organic solvent and initiate the ring-opening reaction of the compound; Step 2: Add an ionic liquid to the above solution and carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; Step 3: Gradually add an organic compound containing amino groups to the prepolymer solution in three portions, and control the molar ratio of the final organic compound containing carboxyl groups to the organic compound containing amino groups to be 1:0.8 ± 0.05. The addition interval is 30 minutes each time. After the reaction is completed, the viscosity of the solution increases significantly; Step 4: Cast the reaction solution into a polytetrafluoroethylene mold, dry it in vacuum at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film in a freezer at -20°C for 12 hours to promote the orderly arrangement of dynamic bonds, and anneal it in an environment with a humidity of 60% RH for 6 hours to eliminate internal stress and enhance interfacial bonding; Step 5: Regulate the mechanical properties of the obtained polymer by adjusting the molar ratio of the organic compound containing carboxyl groups to the organic compound containing amino groups; Step 6: Apply the prepared thin film material to the manufacture of intelligent electronic sensors.

[0007] Furthermore, the organic compound containing carboxyl groups in Step 1 includes one or more of lipoic acid, tannic acid, and vitamin C.

[0008] Furthermore, the anhydrous organic solvent in Step 1 includes anhydrous ethanol, DMAC, dichloromethane, and petroleum ether.

[0009] Furthermore, the ionic liquid used in Step 2 includes one or more of imidazole-based, pyridine-based, and quaternary ammonium salt-based ionic liquids, specifically including one or more of 1-ethyl-3-methylimidazolium chloride (EMIM-Cl), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4), 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIM-PF6), and 1-ethyl-3-methylimidazolium ethyl sulfate (EMIM-ESO4).

[0010] Furthermore, the organic compound containing amino groups used in Step 3 includes one or more of glycine, lysine, alanine, and glutamine.

[0011] Furthermore, the mold described in Step 4 includes one or more of a flat mold, a cylindrical mold, and a microporous mold, and the mold material is one or more of polytetrafluoroethylene, polypropylene, and stainless steel.

[0012] Furthermore, the molar ratio of the organic compound containing carboxyl groups to the organic compound containing amino groups in Step 5 is 1:0.1 to 1:10.

[0013] Further, the intelligent electronic sensor described in step six includes one or more of a pressure sensor, a temperature sensor, a humidity sensor, and a biosensor. Detailed implementation manners

[0014] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] Combined with the above technical solutions and the solved technical problems, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows: First, the present invention proposes a preparation method of a self-healing polymer thin film based on the synergistic effect of dynamic disulfide bonds and ionic liquids. Through the molecular-level interfacial coupling effect of thioctic acid (TA), 1-ethyl-3-methylimidazolium chloride (EMIM-Cl), and glycine (GLY), a polymer thin film material (poly TA-(EMIM-Cl)-GLY) with a three-dimensional dynamic network structure is successfully constructed. This system uses the electron transfer quenching mechanism of the amino group of glycine (GLY) on the mercapto radical to effectively inhibit the network degradation of traditional dynamic disulfide bond polymers caused by free radical chain reactions. At the same time, a continuous charge transport path is formed through the delocalized π-electron system of the ionic liquid, realizing the synchronous optimization of conductivity and reaction kinetics.

[0016] This high-density dynamic cross-linked network endows the material with unique property coupling characteristics: the reversible breakage-recombination behavior of dynamic disulfide bonds enables the material to autonomously repair damaged interfaces at room temperature; the double-layer effect of the ionic liquid and the chalcogen atoms of TA cooperate to construct a stable ion / electron hybrid conductive channel. This characteristic enables the material to meet the stringent requirements of intelligent sensors for signal transmission stability while maintaining the characteristics of the flexible substrate.

[0017] The present invention significantly improves the self-healing characteristics, conductivity, and mechanical stability of the thin film material by adopting a polymer preparation method assisted by dynamic disulfide bonds and ionic liquids. First, the efficient quenching effect of glycine (GLY) on the mercapto radical solves the instability problem of traditional dynamic disulfide bond polymers, and at the same time endows the material with excellent self-healing ability through the reversibility of dynamic disulfide bonds. Second, the introduction of the ionic liquid not only improves the reaction efficiency but also significantly enhances the conductivity of the material through its ionic conductivity. In addition, by adjusting the molar ratio of TA to GLY, precise control of the cross-linking density of the polymer is achieved, thereby optimizing the mechanical properties of the material.

[0018] Through the processing method of the present invention, the thin film material also has excellent self-healing properties. After being mechanically damaged, the material can achieve self-healing at room temperature through the reversibility of dynamic disulfide bonds, thereby significantly extending its service life. This property greatly broadens the application scope of the thin film material, especially in the fields of intelligent electronic sensors and flexible electronic devices.

[0019] Compared with the prior art, the present invention adopts a simple and environmentally friendly preparation method, avoiding high temperature, complex chemical treatment or the use of organic solvents. By using low-cost biological materials (such as lipoic acid, glycine) and ionic liquids, the present invention not only improves the processability of the material, but also has good biocompatibility and environmental friendliness, meeting the requirements of current environmental protection policies. In addition, the reversibility of dynamic disulfide bonds endows the material with good self-healing ability, further enhancing its application value.

[0020] Therefore, the present invention has broad application prospects in the fields of intelligent electronic sensors, flexible electronic devices, wearable devices and other application fields that require high-performance materials.

[0021] Second, as the creative auxiliary evidence of the claims of the present invention, it is also reflected in the following important aspects: (1) The expected benefits and commercial value after the transformation of the technical solution of the present invention are: Due to its unique self-healing properties, high conductivity and good mechanical stability, the self-healing polymer thin film technology of the present invention has broad commercial application potential, especially in high-value-added fields such as intelligent electronic sensors, flexible electronic devices and wearable devices. The expected benefits after transformation include the following aspects: 1. Intelligent electronics field: As the core component of intelligent electronic sensors, the thin film material can be widely used in devices such as pressure sensors, temperature sensors, humidity sensors and biosensors by virtue of its high conductivity and self-healing properties, significantly improving the performance and reliability of the devices. In addition, the self-healing ability of the material can reduce the equipment maintenance and replacement costs and extend the service life. 2. Flexible electronic devices: Since the thin film material of the present invention has both high conductivity and good mechanical properties and has self-healing ability, it can be used as the encapsulation material or conductive layer of flexible electronic components, and is suitable for high-tech products such as touch screens, waterproof electronic devices and sensors, with extremely high commercial value. 3. Sustainable development: The present invention uses green materials (such as lipoic acid, glycine) and ionic liquids, and its low cost and environmental friendliness meet the current global environmental protection trend. It is expected to occupy a place in the market of degradable materials and has good market prospects. By combining with the relevant industrial chain, the thin film material of the present invention can not only meet the market demand, but also significantly increase the added value of products, bringing long-term economic benefits to relevant enterprises.

[0022] (2) The technical solution of the present invention fills the technical gaps at home and abroad in the industry: In the existing self-healing polymer film technology, it is often impossible to achieve a balance among self-healing characteristics, electrical conductivity, and mechanical stability. Moreover, the processing technology is complex, making it difficult to be widely promoted in practical applications. Although there are various studies on self-healing polymer materials at home and abroad, most of them focus on the optimization of single performance, such as improving electrical conductivity or mechanical properties, while ignoring the comprehensive improvement of self-healing characteristics. By introducing dynamic disulfide bonds and an ionic liquid-assisted polymer preparation method, the present invention has achieved the simultaneous improvement of these three key performances for the first time, and a simple low-temperature processing method is adopted, greatly simplifying the preparation process.

[0023] This technology fills the gap in the comprehensive performance of self-healing characteristics, electrical conductivity, and mechanical stability in the field of self-healing polymer films at home and abroad, providing a new direction for the research and application of multifunctional polymer film materials.

[0024] (3) The technical solution of the present invention solves the technical problems that people have been eager to solve but have never succeeded in: For a long time, scientific research personnel have been seeking a polymer film material that has both high electrical conductivity, self-healing characteristics, and good mechanical stability, and can meet the application requirements in different fields (such as intelligent electronics, flexible electronic devices). However, traditional self-healing polymer film materials are prone to fracture under high stress, the electrical conductivity is limited by the material structure, and the self-healing characteristics are difficult to meet the requirements of practical applications. Through the ionic liquid-assisted polymer preparation method with dynamic disulfide bonds, the present invention effectively overcomes these technical problems and develops a film material integrating the three performances, successfully filling the gap in this field for many years.

[0025] (4) The technical solution of the present invention overcomes the technical prejudice: The traditional view holds that the softness and high electrical conductivity of dynamic disulfide bond polymers will inevitably lead to poor mechanical properties, and the pursuit of high mechanical properties usually sacrifices the electrical conductivity or self-healing characteristics of the material. The present invention breaks through this technical prejudice. By reasonably designing the polymer network structure and introducing ionic liquids, while maintaining high electrical conductivity, the mechanical stability and self-healing ability of the film are significantly improved. This innovative design breaks the trade-off between the performance of traditional materials and provides a new idea for the research and development of self-healing polymer films. Description of the Drawings

[0026] Figure 1 It is a sample preparation and processing flow chart provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the stress-strain results after self-healing for 10 minutes in Embodiment Cases 2, 3, and 4 provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the results of stretching 1 time, 3 times, and 5 times respectively in Embodiment Cases 2, 3, and 4 provided by the embodiments of the present invention; Figure 4 It is a large-strain current signal diagram in Embodiment Case 1 provided by the embodiments of the present invention; Figure 5 It is a cyclic stretching current signal diagram in Embodiment Case 1 provided by the embodiments of the present invention. Specific Embodiments

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] As Figure 1 shown, a simple preparation method of a lipoic acid-glycine electronic material with self-healing function provided by the embodiments of the present invention includes the following steps: Step 1, dissolve an organic compound containing a carboxyl group in an anhydrous organic solvent and initiate the ring-opening reaction of the compound; Step 2, add an ionic liquid to the above solution and carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; Step 3, add an organic compound containing an amino group to the prepolymer solution in three gradients, and control the molar ratio of the organic compound containing a carboxyl group to the organic compound containing an amino group to be 1:0.8 ± 0.05. The interval between each addition is 30 minutes. After the reaction is completed, the viscosity of the solution increases significantly; Step 4, pour the reaction solution into a polytetrafluoroethylene mold, vacuum dry at 40°C for 8 hours to form a base film with a thickness of 100-200 μm. Place the base film at -20°C and freeze it for 12 hours to promote the orderly arrangement of dynamic bonds and anneal it in an environment with 60% RH humidity for 6 hours to eliminate internal stress and enhance interfacial bonding; Step 5, immerse the cured film in a swelling preparation material and swell it for 30-120 minutes; Step 6, apply the prepared film material to the manufacture of intelligent electronic sensors.

[0029] In the present invention, first, an organic compound containing a carboxyl group is dissolved in an anhydrous organic solvent, and stirred at room temperature to initiate the ring-opening reaction of the organic compound containing a carboxyl group. Subsequently, an ionic liquid is added to the solution as an ionic liquid promoter, and stirring is continued to mix well. Then, an organic compound containing an amino group is added to the reaction system. After the reaction is completed, the viscosity of the solution increases significantly, indicating the formation of a high-density polymer network. The reaction solution is poured into a mold to prepare a film-like material. By adjusting the molar ratio of the organic compound containing a carboxyl group to the organic compound containing an amino group, the crosslinking density and mechanical properties of the polymer can be precisely controlled.

[0030] In the present invention, glycine (GLY) is preferably selected as the polymer, lipoic acid as the organic acid, and absolute ethanol as the solvent. The concentration of glycine (GLY) dissolved in water is 20 wt%, and the content of lipoic acid dissolved in water as a solution is 1 mol%.

[0031] In the present invention, the temperature is preferably 25 °C and the stirring time is 2 hours.

[0032] In the present invention, a strip shape is preferably selected as the shape of the initial sample to demonstrate the self-healing and sensing stability properties of the lipoic acid and glycine sensing materials.

[0033] In the present invention, annealing treatment is preferably carried out in a humidity environment of 60% RH for 6 hours.

[0034] In the present invention, an ethanol solution of 0.1 M HCl (volume ratio 1:3) is preferably selected to swell the preparatory material, and the swelling time is 30 min.

[0035] Glycine (GLY), lipoic acid (TA), and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) were purchased from Adamas-β®. Absolute ethanol was from Sigma-Aldrich. All chemical reagents were used as received without further purification.

[0036] Example 1 A preparation method of a reparable intelligent electronic sensor based on lipoic acid and glycine, comprising the following steps: Dissolve lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) in a tetrahydrofuran solvent at a molar ratio of 1:1.5; carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; add glycine (GLY) to the prepolymer solution in three gradient steps, controlling the final TA:GLY molar ratio to be 1:0.8 ± 0.05, with an interval of 30 minutes between each addition; cast the reaction solution into a polytetrafluoroethylene mold and dry it under vacuum at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film at -20°C and freeze it for 12 hours to promote the ordered arrangement of dynamic bonds, and anneal it in an environment with 60% RH humidity for 6 hours to eliminate internal stress and enhance interfacial bonding; immerse the cured film in an ethanol solution containing 0.1 M HCl (volume ratio 1:3) and swell it for 30 minutes; apply the prepared film to the manufacture of intelligent electronic sensors.

[0037] Example 2 A preparation method of a repairable intelligent electronic sensor based on lipoic acid and 1-ethyl-tripropylimidazolium chloride, comprising the following steps: Dissolve lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) in a tetrahydrofuran solvent at a molar ratio of 1:3; carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; add glycine (GLY) to the prepolymer solution in three gradient steps, controlling the final TA:GLY molar ratio to be 1:0.8 ± 0.05, with an interval of 30 minutes between each addition; cast the reaction solution into a polytetrafluoroethylene mold and dry it under vacuum at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film at -20°C and freeze it for 12 hours to promote the ordered arrangement of dynamic bonds, and anneal it in an environment with 60% RH humidity for 6 hours to eliminate internal stress and enhance interfacial bonding; immerse the cured film in an ethanol solution containing 0.1 M HCl (volume ratio 1:3) and swell it for 30 minutes; apply the prepared film to the manufacture of intelligent electronic sensors.

[0038] Example 3 A preparation method of a repairable intelligent electronic sensor based on lipoic acid and 1-ethyl-tripropylimidazolium chloride, comprising the following steps: Dissolve lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) in a tetrahydrofuran solvent at a molar ratio of 1:5; carry out a ring-opening polymerization reaction for 3 hours at 65°C ± 2°C under nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; add glycine (GLY) to the prepolymer solution in three gradients, controlling the final TA:GLY molar ratio to be 1:0.8 ± 0.05, with a 30-minute interval between each addition; cast the reaction solution into a polytetrafluoroethylene mold and vacuum dry it at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film at -20°C for 12 hours to promote the ordered arrangement of dynamic bonds, and carry out annealing treatment for 6 hours in an environment with 60% RH humidity to eliminate internal stress and enhance interfacial bonding; immerse the cured film in an ethanol solution containing 0.1 M HCl (volume ratio 1:3) for swelling for 30 minutes; apply the prepared film to the manufacture of intelligent electronic sensors.

[0039] Example 4 A preparation method of a repairable intelligent electronic sensor based on lipoic acid and 1-ethyl-tripropylimidazolium chloride, comprising the following steps: Dissolve lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) in a tetrahydrofuran solvent at a molar ratio of 1:7; carry out a ring-opening polymerization reaction for 3 hours at 65°C ± 2°C under nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; add glycine (GLY) to the prepolymer solution in three gradients, controlling the final TA:GLY molar ratio to be 1:0.8 ± 0.05, with a 30-minute interval between each addition; cast the reaction solution into a polytetrafluoroethylene mold and vacuum dry it at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film at -20°C for 12 hours to promote the ordered arrangement of dynamic bonds, and carry out annealing treatment for 6 hours in an environment with 60% RH humidity to eliminate internal stress and enhance interfacial bonding; immerse the cured film in an ethanol solution containing 0.1 M HCl (volume ratio 1:3) for swelling for 30 minutes; apply the prepared film to the manufacture of intelligent electronic sensors.

[0040] Example 5 A preparation method of a repairable intelligent electronic sensor based on lipoic acid and 1-ethyl-tripropylimidazolium chloride, comprising the following steps: Dissolve lipoic acid (TA) and 1-ethyl-tripropylimidazolium chloride (EMIM-Cl) in a tetrahydrofuran solvent at a molar ratio of 1:9; carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network; add glycine (GLY) to the prepolymer solution in three gradients, controlling the final TA:GLY molar ratio to be 1:0.8 ± 0.05, with an interval of 30 minutes for each addition; cast the reaction solution into a polytetrafluoroethylene mold and vacuum dry it at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm, place the base film at -20°C for freezing for 12 hours to promote the ordered arrangement of dynamic bonds, and anneal it in an environment with 60% RH humidity for 6 hours to eliminate internal stress and enhance interfacial bonding; immerse the cured film in an ethanol solution containing 0.1 M HCl (volume ratio 1:3) for swelling for 30 minutes; apply the prepared film to the manufacture of intelligent electronic sensors.

[0041] These examples demonstrate the multi-scenario applicability of lipoic acid-glycine electronic materials based on a dynamic disulfide bond cooperative system in the fields of flexible electronics (such as intelligent electronic skin, stretchable circuits) and biomedical (such as physiological signal sensing patches, implantable electrodes), etc., according to the described claims. By adjusting the composition and processing conditions of the polymer, applications under different environmental factors can be achieved, thus meeting various actual application requirements.

[0042] The present invention provides a preparation method of a self-healing, highly conductive and environmentally stable lipoic acid-glycine electronic material. Through the cooperative design of dynamic bonds and gradient process regulation, the material has excellent self-healing characteristics, conductive stability and mechanical adaptability. This method realizes a breakthrough in the functional integration of electronic materials through the precise construction of the cross-scale cooperation of a molecular-scale dynamic network and a mesoscopic-scale ion transport channel, and has important application value in the fields of intelligent sensors, flexible electronic systems and bio-integrated devices.

[0043] 1. Dynamic network prefabrication: In the first and second steps, a dynamic disulfide bond network is constructed in a tetrahydrofuran solvent by controlling the molar ratio of lipoic acid (TA) and ionic liquid (EMIM-Cl). This step carries out a ring-opening polymerization reaction under nitrogen protection to form a prepolymer solution with topological reversibility characteristics. The core function of this process is to establish the structural basis for the self-healing function of the material, and at the same time, initially form an ion transport channel through the intercalation effect of the ionic liquid.

[0044] 2. Functional collaborative modification: In the third step, glycine (GLY) is introduced in stages to achieve molecular-level functional synergy. Through a three-step gradient addition strategy, the capture efficiency of amino groups for thiol radicals is precisely regulated, and at the same time, a multiple hydrogen bond network is constructed using the carboxyl-amino interaction to dissipate energy. The key to this step is to balance the dynamic bond reconstruction rate and network stability to provide suitable rheological properties for subsequent processing.

[0045] 3. Multilevel structure regulation: In the fourth step, a temperature-humidity gradient control strategy is adopted to optimize the mesoscopic structure of the material in three stages: 1. Primary film formation: Residual solvents are removed by vacuum drying to form a continuous and uniform matrix film; 2. Microcrystal induction: Low-temperature freezing promotes the oriented arrangement of dynamic disulfide bonds to enhance the interfacial bonding strength; 3. Interface stabilization: Hydrothermal annealing eliminates internal stress and improves the environmental stability of the material.

[0046] 4. Functional enhancement treatment: In the fifth step, functional activation is achieved through the swelling effect of acidic ethanol solution. This process selectively expands the nano-scale channels formed by ionic liquids and simultaneously induces the self-organization of surface microporous structures. This treatment significantly enhances the interfacial charge transfer efficiency of the material and improves the adhesion compatibility with flexible substrates.

[0047] Through this series of steps, the processing method of the present invention successfully endows the lipoic acid-glycine electronic material with the core characteristics of self-repair, high conductivity, and environmental stability, and can prepare miniaturized functional components that meet the requirements of flexible electronic devices through gradient assembly technology. This method not only simplifies the controllable forming process of dynamic network materials but also significantly improves the functional retention rate and service durability of the materials under complex deformation conditions through innovative design of molecular-scale interface engineering.

[0048] Example 1: Self-repairing electronic material for electronic skin 1. Dynamic network prefabrication: Thioctic acid (TA) and (EMIM-Cl) are dissolved in tetrahydrofuran at a molar ratio of 1:1.5, and a ring-opening polymerization reaction is carried out for 3 hours under nitrogen protection to prepare a prepolymer solution with a dynamic disulfide bond network.

[0049] 2. Functional collaborative modification: Glycine (GLY) is added in three gradients, and the final molar ratio of TA:GLY is controlled at 1:0.8. At 45 °C, free radical quenching and hydrogen bond network construction are simultaneously achieved to obtain a composite solution with controllable viscoelasticity.

[0050] 3. Gradient curing and forming: The solution is cast onto a polyimide substrate and sequentially subjected to: 1. Vacuum drying at 40 °C for 8 hours to form a primary film; 2. Low-temperature induction at -20 °C to order the dynamic bonds; 3. Humidity annealing at 60% RH to stabilize the interface structure. 4. Surface functionalization treatment: Immerse the thin film in a 0.1M HCl / ethanol mixture for 30 minutes to swell it, obtaining an electronic skin substrate with a micro-nano topological structure on the surface.

[0051] Application effect: The electronic skin prepared from this material exhibits excellent deformation adaptability, maintaining stable electrical signal transmission under repeated bending (radius of curvature ≤ 2 mm). Its self-healing property can effectively recover local conductive failure caused by mechanical damage, and it is suitable for human motion monitoring and human-machine interaction interfaces.

[0052] Example 2: Self-healing electronic materials for implantable bioelectrodes 1. Dynamic network prefabrication: Select medical-grade lipoic acid (TA) and (EMIM-Cl) to react in a molar ratio of 1:2 to prepare a biocompatible dynamic network prepolymer.

[0053] 2. Functionalized co-modification: Introduce glycine (GLY) in stages, controlling the TA:GLY molar ratio to 1:0.5, and construct a biomimetic adhesion interface by the directional capture of free radicals by amino groups.

[0054] 3. Multilevel structure regulation: Adopt a three-step forming process: 1. Vacuum drying at 50 °C to form a porous matrix; 2. Quick-freezing with liquid nitrogen to fix the mesoscopic structure; 3. Annealing at 60% RH to stabilize the interface structure.

[0055] 4. Bio-functionalization treatment: Immerse the material in a PBS solution containing collagen to graft bioactive molecules through hydrogen bonding.

[0056] Application effect: The obtained bioelectrode material exhibits stable impedance characteristics (< 10 Ω·cm²) in a simulated body fluid environment. Its dynamic network structure can adapt to the deformation stress generated by tissue micro-movement, and its self-healing property effectively extends the service life of implanted devices, making it suitable for deep brain stimulation electrodes and cardiac pacing lead encapsulation.

[0057] II. Evidence related to the technical effects obtained in the embodiments of the present invention.

[0058] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0059] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A preparation method and application of a lipoic acid-glycine electronic material with self-healing function, characterized in that, Comprising: Step 1: Dissolve an organic compound containing a carboxyl group in an anhydrous organic solvent and initiate the ring-opening reaction of the compound. Step 2: Add an ionic liquid to the above solution and carry out a ring-opening polymerization reaction for 3 hours under the conditions of 65°C ± 2°C and nitrogen protection to form a prepolymer solution with a dynamic disulfide bond network. Step 3: Gradually add an organic compound containing an amino group to the prepolymer solution in three portions, controlling the molar ratio of the final organic compound containing a carboxyl group to the organic compound containing an amino group to be 1:0.8 ± 0.

05. Each addition is spaced 30 minutes apart. After the reaction is completed, the viscosity of the solution increases significantly. Step 4: Cast the reaction solution into a polytetrafluoroethylene mold and vacuum dry it at 40°C for 8 hours to form a base film with a thickness of 100 - 200 μm. Place the base film at -20°C and freeze it for 12 hours to promote the orderly arrangement of dynamic bonds. Anneal it in an environment with 60% RH humidity for 6 hours to eliminate internal stress and enhance interfacial bonding. Step 5: Regulate the mechanical properties of the obtained polymer by adjusting the molar ratio of the organic compound containing a carboxyl group to the organic compound containing an amino group. Step 6: Apply the prepared thin film material to the manufacture of intelligent electronic sensors.

2. The preparation method and application of a lipoic acid-glycine electronic material with a self-healing function as claimed in claim 1, characterized in that, The organic compound containing a carboxyl group in Step 1 includes one or more of lipoic acid, tannic acid, and vitamin C.

3. The preparation method and application of a lipoic acid-glycine electronic material with self-healing function according to claim 1, characterized in that, The anhydrous organic solvent in Step 1 includes anhydrous ethanol, DMAC, dichloromethane, and petroleum ether.

4. The preparation method and application of a lipoic acid-glycine electronic material with a self-healing function according to claim 1, characterized in that, The ionic liquid used in Step 2 includes one or more of imidazole-based, pyridine-based, and quaternary ammonium salt-based ionic liquids, specifically including one or more of 1-ethyl-3-methylimidazolium chloride (EMIM-Cl), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4), 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIM-PF6), and 1-ethyl-3-methylimidazolium ethyl sulfate (EMIM-ESO4).

5. The preparation method and application of a lipoic acid-glycine electronic material with a self-healing function as claimed in claim 1, characterized in that, The organic compound containing an amino group used in Step 3 includes one or more of glycine, lysine, alanine, and glutamine.

6. The preparation method and application of a lipoic acid-glycine electronic material with self-healing function according to claim 1, characterized in that, The mold described in Step 4 includes one or more of a flat mold, a cylindrical mold, and a microporous mold, and the mold material is one or more of polytetrafluoroethylene, polypropylene, and stainless steel.

7. The preparation method and application of a lipoic acid-glycine electronic material with a self-healing function as claimed in claim 1, characterized in that The molar ratio of the organic compound containing a carboxyl group to the organic compound containing an amino group described in Step 5 is 1:0.1 to 1:

10.

8. The preparation method and application of a lipoic acid-glycine electronic material with a self-healing function according to claim 1, characterized in that, The intelligent electronic sensor described in Step 6 includes one or more of a pressure sensor, a temperature sensor, a humidity sensor, and a biosensor.

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