Polyethylene glycol-based conductive self-repairing hydrogel modified by imidazolium salt structure as well as preparation method and application of polyethylene glycol-based conductive self-repairing hydrogel

Abstract

The invention provides imidazolium salt structure modified polyethylene glycol-based conductive self-repairing hydrogel as well as a preparation method and application thereof. Relates to the field of functional polymer materials. An imidazolium salt ionic conductive structure is introduced into two ends of polyethylene glycol (PEG), so that the imidazolium salt ionic conductive structure and a polyamino / hydrazide group-containing component are subjected to dynamic Schiff base reaction to form a two-component cross-linked network, and the polyethylene glycol hydrogel capable of maintaining the conductivity after self-repairing is prepared; the hydrogel prepared by the method shows excellent electrical conductivity and good biocompatibility after self-repairing, has adjustable mechanical properties and degradation rate, and has wide application prospects in a plurality of fields such as flexible electronics, electronic skin, biosensors, nerve interfaces, soft robots and skin wound repair promoting materials.

Description

Technical Field

[0001] The present invention belongs to the field of functional polymer materials, and in particular relates to an imidazolium salt structure-modified polyethylene glycol-based conductive self-repairing hydrogel, and a preparation method and application thereof. Background Art

[0002] Conductive hydrogels have shown great potential in flexible electronic devices (such as wearable sensors, electronic skin) and biomedical applications (such as biosensors, tissue engineering scaffolds, and implantable devices) due to their unique conductivity, flexibility, and biocompatibility.

[0003] Among them, polyethylene glycol (PEG) hydrogels are regarded as ideal substrates for biomedical applications such as tissue engineering, drug delivery and regenerative medicine due to their excellent biocompatibility, controllable degradation properties, highly customizable ideal performance, easy multifunctional modification and good resistance to protein adsorption.

[0004] However, the inherent insulating properties of polyethylene glycol (PEG) hydrogels severely limit their conductive applications. Conventional conductive modification strategies (such as direct doping with highly conductive nanomaterials) can partially improve conductivity, but often come at the expense of PEG's core advantages: the introduction of nanofillers may disrupt the integrity of the PEG molecular network and interfere with its cross-linking structure, leading to deterioration of the hydrogel's mechanical properties (such as brittleness or softening). It may also affect its controlled degradation behavior, resulting in unpredictable degradation rates or byproducts, and even affecting its biocompatibility.

[0005] Therefore, it is urgent to provide a solution to improve the above problems. Summary of the Invention

[0006] The present invention aims to provide a polyethylene glycol-based conductive self-healing hydrogel modified with an imidazolium salt structure, as well as its preparation method and application. This invention introduces an imidazolium salt ion-conducting structure at both ends of polyethylene glycol (PEG), which reacts with a polyamino / hydrazide-containing component through a dynamic Schiff base reaction to form a two-component cross-linked network. This allows the preparation of a polyethylene glycol hydrogel that maintains conductive properties after self-healing.

[0007] In the first aspect, the present invention provides an imidazole salt-modified polyethylene glycol having a structure as shown in formula (I):

[0008]

[0009] Wherein, n is a positive integer between 43 and 1000;

[0010] The structure of R1 is One of the following;

[0011] R2 is one of chlorine, bromine and iodine;

[0012] R3 is one of hydrogen, chlorine, and methyl;

[0013] R4 is one of hydrogen and methyl;

[0014] R5 is one of hydrogen and chlorine;

[0015] R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy;

[0016] R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro;

[0017] R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy;

[0018] R9 is one of hydrogen and hydroxymethyl;

[0019] R 10 It is one of hydrogen, chlorine, methyl and ethyl.

[0020] In a second aspect, the present invention provides a method for synthesizing an imidazole salt-modified polyethylene glycol having a structure as shown in formula (I), comprising the following steps: in a solvent environment, in the presence of a catalyst, polyethylene glycol and a sulfonylating agent undergo a nucleophilic substitution reaction to generate sulfonylated polyethylene glycol; the sulfonylated polyethylene glycol and an imidazole compound undergo a nucleophilic substitution reaction to generate imidazole-terminated polyethylene glycol; and the imidazole-terminated polyethylene glycol undergoes a quaternization reaction with 4-(chloromethyl)benzaldehyde to obtain polyethylene glycol modified with an imidazole salt structure; wherein the structure of the imidazole compound is one of the compounds represented by formula (II) or formula (III):

[0021]

[0022] Optionally, the sulfonylating agent includes one of benzenesulfonyl chloride, p-toluenesulfonyl chloride and methanesulfonyl chloride.

[0023] Optionally, the organic solvent includes one of dichloromethane, chloroform or tetrahydrofuran.

[0024] Optionally, the catalyst includes one of triethylamine, diisopropylethylamine, and pyridine.

[0025] Alternatively, 4-(chloromethyl)benzaldehyde is synthesized by esterification of p-hydroxybenzaldehyde and 4-(chloromethyl)benzoyl chloride.

[0026] In a third aspect, the present invention provides a method for preparing an imidazolium salt-modified polyethylene glycol hydrogel, comprising: dissolving polyethylene glycol modified with an imidazolium salt structure in solvent a to obtain component A; dissolving a gelling agent in solvent b to obtain component B; and mixing the solution of component A with the solution of component B to obtain the imidazolium salt-modified polyethylene glycol hydrogel. The structural formula of the imidazolium salt-modified polyethylene glycol is:

[0027]

[0028] Wherein, n is a positive integer between 43 and 1000;

[0029] The structure of R1 is One of the following;

[0030] R2 is one of chlorine, bromine and iodine;

[0031] R3 is one of hydrogen, chlorine, and methyl;

[0032] R4 is one of hydrogen and methyl;

[0033] R5 is one of hydrogen and chlorine;

[0034] R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy;

[0035] R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro;

[0036] R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy;

[0037] R9 is one of hydrogen and hydroxymethyl;

[0038] R 10 It is one of hydrogen, chlorine, methyl and ethyl.

[0039] Optionally, the solvent a comprises a phosphate buffer solution.

[0040] Optionally, the gelling agent comprises one of ε-polylysine, chitosan, N-trimethyl chitosan chloride, O-carboxymethyl chitosan, hydrazide-modified hyaluronic acid, polyethyleneimine, and gelatin.

[0041] Optionally, the solvent b includes one of 2 wt % acetic acid aqueous solution, physiological saline, and phosphate buffer solution.

[0042] Optionally, the solid content of the component A solution is 12 wt%-50 wt%.

[0043] Optionally, the solid content of the component B solution is 3.5 wt%-30 wt%.

[0044] Optionally, the volume ratio of the component A solution to the component B solution is (0.001-1):(0.001-1).

[0045] Optionally, the reaction temperature of the mixing reaction is 0°C-45°C.

[0046] Optionally, the pH is 6-12.

[0047] In a fourth aspect, the present invention further provides a polyethylene glycol hydrogel modified with an imidazole salt structure prepared by any optional preparation method of the third aspect.

[0048] In the fifth aspect, the present invention also provides an application of a polyethylene glycol hydrogel modified with an imidazole salt structure prepared by any optional preparation method of the third aspect, including use in any of the following fields: flexible electronic materials, electronic skin, biosensors, neural interfaces or soft robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The molecular structure diagram of polyethylene glycol modified with imidazolium salt structure;

[0050] Figure 2 This is the NMR spectrum of polyethylene glycol modified with imidazolium salt structure;

[0051] Figure 3 This is the infrared spectrum of the hydrogel prepared by polyethylene glycol modified with imidazolium salt and chitosan;

[0052] Figure 4 This is a graph showing the tensile properties of hydrogels made from imidazolium salt-modified polyethylene glycol and chitosan;

[0053] Figure 5 This is a diagram showing the self-healing performance of hydrogels made from imidazolium salt-modified polyethylene glycol and chitosan;

[0054] Figure 6 This is a live-dead cell staining image of the hydrogel made of polyethylene glycol modified with imidazolium salt structure and chitosan. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0056] The present invention provides an imidazole salt-modified polyethylene glycol having a structure shown in formula (I):

[0057]

[0058] Wherein, n is a positive integer between 43 and 1000;

[0059] The structure of R1 is One of the following;

[0060] R2 is one of chlorine, bromine and iodine;

[0061] R3 is one of hydrogen, chlorine, and methyl;

[0062] R4 is one of hydrogen and methyl;

[0063] R5 is one of hydrogen and chlorine;

[0064] R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy;

[0065] R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro;

[0066] R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy;

[0067] R9 is one of hydrogen and hydroxymethyl;

[0068] R 10 It is one of hydrogen, chlorine, methyl and ethyl.

[0069] An imidazolium salt conductive group and an aldehyde cross-linking site are connected to the two ends of the polyethylene glycol (PEG) chain to synthesize a specific structure of "imidazole salt-polyethylene glycol-aldehyde" three-unit. In fact, by introducing the imidazolium salt ion conductive structure into polyethylene glycol (PEG), it reacts with the multi-amino / hydrazide group-containing component through a dynamic Schiff base reaction to form a two-component cross-linking network, and thus prepares a polyethylene glycol hydrogel that maintains conductive properties after self-repair. The hydrogel prepared in this way exhibits excellent conductivity and good biocompatibility after self-repair, and has adjustable mechanical properties and degradation rate. It has broad application prospects in many fields such as flexible electronics, electronic skin, biosensors, neural interfaces, soft robots, and skin wound repair materials.

[0070] The present invention also provides a method for preparing an imidazole salt structure-modified polyethylene glycol having a structure as shown in formula (I), comprising the following steps: in a solvent environment and under the action of a catalyst, polyethylene glycol and a sulfonylating agent undergo a nucleophilic substitution reaction to generate sulfonated polyethylene glycol; the sulfonated polyethylene glycol and an imidazole compound undergo a nucleophilic substitution reaction to generate imidazole-terminated polyethylene glycol; and the imidazole-terminated polyethylene glycol undergoes a quaternization reaction with 4-(chloromethyl)benzaldehyde to obtain imidazole salt structure-modified polyethylene glycol; wherein the structure of the imidazole compound is one of the compounds shown in formula (II) or formula (III):

[0071]

[0072]

[0073] In some embodiments, the sulfonylating agent comprises one of benzenesulfonyl chloride, p-toluenesulfonyl chloride, and methanesulfonyl chloride. The organic solvent for dissolving the polyethylene glycol comprises one of dichloromethane, chloroform, or tetrahydrofuran. In practice, the organic solvent used is necessary to dissolve the polyethylene glycol and the sulfonylating agent to ensure adequate mixing of the reactants.

[0074] In some embodiments, the catalyst used includes one of triethylamine, diisopropylethylamine, and pyridine. In fact, the catalyst can not only promote the formation of sulfonyl oxide but also neutralize the HCl generated in the reaction, thereby promoting the reaction equilibrium.

[0075] Specifically, 4-(chloromethyl)benzaldehyde is synthesized by esterification reaction of p-hydroxybenzaldehyde and 4-(chloromethyl)benzoyl chloride.

[0076] The present invention also provides a method for preparing an imidazolate-modified polyethylene glycol hydrogel, comprising: dissolving imidazolate-modified polyethylene glycol in solvent a to obtain component A; dissolving a gelling agent in solvent b to obtain component B; and mixing the solution of component A with the solution of component B to obtain the imidazolate-modified polyethylene glycol hydrogel. The structural formula of the imidazolate-modified polyethylene glycol is:

[0077]

[0078] Wherein, n is a positive integer between 43 and 1000;

[0079] The structure of R1 is One of the following;

[0080] R2 is one of chlorine, bromine and iodine;

[0081] R3 is one of hydrogen, chlorine, and methyl;

[0082] R4 is one of hydrogen and methyl;

[0083] R5 is one of hydrogen and chlorine;

[0084] R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy;

[0085] R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro;

[0086] R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy;

[0087] R9 is one of hydrogen and hydroxymethyl;

[0088] R 10 It is one of hydrogen, chlorine, methyl and ethyl.

[0089] In some embodiments, the solvent a used in preparing component A includes physiological saline or phosphate buffer solution. In practice, by selecting an appropriate solvent a, component A can be dissolved, ensuring uniform mixing; maintaining the desired pH environment for the reaction, ensuring that the aldehyde groups of the imidazole salt-modified polyethylene glycol react with the amino groups of the gelling agent to form a Schiff base reaction, and avoiding excessive reaction under acidic conditions or auto-oxidation of the aldehyde groups under alkaline conditions.

[0090] In some embodiments, the gelling agent used in preparing component B includes one of ε-polylysine, chitosan, N-trimethylchitosan chloride, O-carboxymethylchitosan, hydrazide-modified hyaluronic acid, polyethyleneimine, and gelatin. In practice, the gelling agent provides amino (-NH2) or hydrazide (-NH-NH2) groups, which form dynamic Schiff base bonds with the aldehyde groups of component A, thereby imparting self-healing properties to the hydrogel.

[0091] In some embodiments, the solvent b used in preparing component B includes one of a 2 wt% aqueous acetic acid solution, physiological saline, and a phosphate buffer solution. In practice, the solvent b used must be able to dissolve component B, ensure uniform mixing, and be able to adjust the pH to a stable state, without disrupting the rate of the Schiff base reaction after mixing components A and B, or the stability of the resulting hydrogel.

[0092] Specifically, when component B is chitosan, the solvent b is selected from 2 wt% acetic acid aqueous solution; when component B is ε-polylysine, N-trimethyl chitosan chloride, O-carboxymethyl chitosan, hydrazide-modified hyaluronic acid, polyethyleneimine or gelatin, the solvent b is selected from physiological saline and phosphate buffer solution.

[0093] In some embodiments, the solid content of the component A solution is 12wt%-50wt%; the solid content of the component B solution is 3.5wt%-30wt%; the volume ratio of the component A solution to the component B solution is (0.001-1): (0.001-1); the reaction temperature of the mixing reaction is 0°C-45°C; the pH is 6-12, specifically, the pH is preferably 7.4.

[0094] Example 1:

[0095] This embodiment provides a method for preparing imidazole salt structure-modified polyethylene glycol:

[0096] (1) Preparation of sulfonylated polyethylene glycol: polyethylene glycol PEG with a molecular weight of 2000 2000The PEG-7-sulfonated polyethylene glycol (BSC) (6.0 g, 3 mmol) was dissolved in ultra-dry dichloromethane (CH2Cl2) (DCM, 25 ml). Benzenesulfonyl chloride (BSC) (2.2 g, 12 mmol) was dissolved in DCM (20 ml) and added dropwise to the PEG solution while stirring. Subsequently, triethylamine (3 ml) was added to the mixed solution. The crude mixture was filtered twice and concentrated by rotary evaporation. The filtrate was dried over MgSO4 for 1 hour, concentrated by rotary evaporation, and settled into icy ether. The sulfonylated polyethylene glycol BSC-PEG was dried in vacuo to constant weight to give a white viscous solid (7.03 g) in a yield of 84.7%.

[0097] (2) Preparation of imidazole salt structure-modified polyethylene glycol:

[0098] (a) Synthesis of 4-(chloromethyl)benzaldehyde: Triethylamine (2.5 ml) and 4-(chloromethyl)benzoyl chloride (1.5 g, 8.0 mmol) were added dropwise to a solution of p-hydroxybenzaldehyde (1 g, 8.20 mmol) in tetrahydrofuran (THF) (20 ml) at 0° C. The reaction mixture was stirred at room temperature for 6 hours, poured into ice water (1000 mL), recrystallized from CHCl₃, and dried under a N₂ atmosphere at 30° C. for 48 hours to obtain 4-(chloromethyl)benzaldehyde as a white solid (2.21 g) in a 91.7% yield.

[0099] (b) Synthesis of Imidazole-Terminated Polyethylene Glycol: Cs2CO3 (1.1 g, 3.5 mmol) and imidazole (0.24 g, 3.5 mmol) were added sequentially to a solution in acetone (50 mL). BSC-PEG (2 g, 1 mmol) was dissolved in acetone (10 mL) and added dropwise. The suspension was stirred at 50°C for 48 hours, cooled to ambient temperature, and concentrated on a rotary evaporator. The residue was partitioned between DCM (2 x 20 mL) and H2O (30 mL). The separated organic layer was dried over MgSO4 and evaporated to dryness to give an oil. The oil was precipitated into cold diethyl ether and dried at 50°C under N2 to constant weight for 48 hours to give the imidazole-terminated polyethylene glycol as a yellow semisolid (1.88 g) in 85.8% yield.

[0100] (c) Synthesis of Imidazole Salt-Modified Polyethylene Glycol: First, imidazole-terminated polyethylene glycol (6 g, 3 mmol) and 4-(chloromethyl)benzaldehyde (3 g, 10 mmol) were added to toluene to form a suspension. The suspension was stirred at 100° C. under N 2 for 48 hours. After the reaction was completed, the mixture was cooled to room temperature and concentrated under reduced pressure to remove most of the toluene. The residue was extracted between toluene and H 2 O (20 ml). The separated aqueous layer was washed with water (20 ml) and ethyl acetate (20 ml), respectively. The separated aqueous layer was evaporated under vacuum to remove water. The final product was a yellow viscous solid (7.96 g) of imidazole salt-modified polyethylene glycol with a yield of 88.2%. Figure 2 This is the NMR spectrum of the imidazole salt structure-modified polyethylene glycol prepared in Example 1.

[0101] Example 2

[0102] This example provides a method for preparing an imidazole salt structure-modified polyethylene glycol hydrogel:

[0103] A certain amount of chitosan was dissolved in a 2% (by weight) aqueous acetic acid solution to prepare a 3.5% (by weight) chitosan solution. 2.0 g of the imidazole salt-modified polyethylene glycol prepared in Example 1 was dissolved in 8.0 g of phosphate buffer solution (pH 7.4) to obtain a 20% (by weight) imidazole salt-modified polyethylene glycol solution. According to the following hydrogel preparation method, 1.2 g of the imidazole salt-modified polyethylene glycol solution was added to 1 g of the chitosan solution at a temperature of 25° C. and the mixture was reacted to form an imidazole salt-modified polyethylene glycol hydrogel. Figures 3 to 6 These are the infrared spectrum, tensile performance graph, self-repair performance graph, and live-dead cell staining graph of the hydrogel prepared from the imidazole salt structure-modified polyethylene glycol and chitosan prepared in Example 2.

[0104] Figure 1 This is the molecular structure diagram of polyethylene glycol modified with imidazolium salt structure.

[0105] Wherein, n is a positive integer between 43 and 1000;

[0106] The structure of R1 is One of the following;

[0107] R2 is one of chlorine, bromine and iodine;

[0108] R3 is one of hydrogen, chlorine, and methyl;

[0109] R4 is one of hydrogen and methyl;

[0110] R5 is one of hydrogen and chlorine;

[0111] R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy;

[0112] R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro;

[0113] R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy;

[0114] R9 is one of hydrogen and hydroxymethyl;

[0115] R 10 It is one of hydrogen, chlorine, methyl and ethyl.

[0116] like Figure 2 As shown, Figure 2 The position a in the figure is the chemical shift of the hydrogen atom on the aldehyde group of the synthetic imidazolium salt structure-modified polyethylene glycol, bh is the chemical shift of the hydrogen atom on the imidazole ring, i and j are the chemical shifts of the hydrogen atoms on the backbone polyethylene glycol, and k is the chemical shift of the hydrogen atom on the methylene group connected to the imidazole ring.

[0117] like Figure 3 As shown, Figure 3 The 1643cm marked -1 The wavenumbers are the stretching vibrations of the Schiff base bonds formed by the hydrogel.

[0118] like Figure 4 As shown, Figure 4 The mesohydrogel has a tensile stress of 60 kPa and a tensile strain of 14.3%, which can basically meet the conditions of use.

[0119] like Figure 5 As shown, Figure 5 The hydrogel exhibits self-healing properties. Under a constant frequency and a small strain of 1%, the hydrogel maintains its original shape, and the storage modulus (G') is greater than the loss modulus (G"). When it is changed to a large strain of 500%, the hydrogel is damaged, and the storage modulus (G') is less than the loss modulus (G"). However, when it is changed to a small strain of 1%, the hydrogel returns to its original shape, and the storage modulus (G') is greater than the loss modulus (G"). This proves that the hydrogel has self-healing properties.

[0120] like Figure 6 As shown, red represents dead cells and green represents living cells. It can be seen that the vast majority of cells remain alive within three days, proving that the material has good biocompatibility.

[0121] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. An imidazole salt-modified polyethylene glycol having a structure as shown in formula (I): in, n is a positive integer between 43 and 1000; The structure of R1 is One of the following; R2 is one of chlorine, bromine and iodine; R3 is one of hydrogen, chlorine, and methyl; R4 is one of hydrogen and methyl; R5 is one of hydrogen and chlorine; R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy; R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro; R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy; R9 is one of hydrogen and hydroxymethyl; R 10 It is one of hydrogen, chlorine, methyl and ethyl.

2. A method for synthesizing polyethylene glycol modified with an imidazole salt structure as claimed in claim 1, characterized in that: The following steps are included: In a solvent environment and under the action of a catalyst, polyethylene glycol undergoes a nucleophilic substitution reaction with a sulfonylating agent to generate sulfonylated polyethylene glycol; Sulfonylated polyethylene glycol and an imidazole compound are reacted through a nucleophilic substitution reaction to generate imidazole-terminated polyethylene glycol; the imidazole-terminated polyethylene glycol is then reacted with 4-(chloromethyl)benzaldehyde through a quaternization reaction to obtain polyethylene glycol modified with an imidazole salt structure; wherein the structure of the imidazole compound is one of the compounds represented by formula (II) or formula (III):

3. The synthesis method according to claim 2, characterized in that The sulfonylating agent includes one of benzenesulfonyl chloride, p-toluenesulfonyl chloride, and methanesulfonyl chloride; and / or, the organic solvent includes one of dichloromethane, chloroform, or tetrahydrofuran; and / or, the catalyst includes one of triethylamine, diisopropylethylamine, and pyridine; and / or, 4-(chloromethyl)benzaldehyde is synthesized by an esterification reaction between p-hydroxybenzaldehyde and 4-(chloromethyl)benzoyl chloride.

4. A method for preparing an imidazole salt-modified polyethylene glycol hydrogel, characterized in that: The imidazolium salt structure-modified polyethylene glycol is dissolved in solvent a to obtain component A; the gelling agent is dissolved in solvent b to obtain component B; the component A solution and the component B solution are mixed and reacted to obtain the imidazolium salt structure-modified polyethylene glycol hydrogel; the structural formula of the imidazolium salt structure-modified polyethylene glycol is: Wherein, n is a positive integer between 43 and 1000; The structure of R1 is One of the following; R2 is one of chlorine, bromine and iodine; R3 is one of hydrogen, chlorine, and methyl; R4 is one of hydrogen and methyl; R5 is one of hydrogen and chlorine; R6 is one of hydrogen, chlorine, methyl, nitro, and methoxy; R7 is one of hydrogen, chlorine, iodine, methyl, trifluoromethyl, and nitro; R8 is one of hydrogen, chlorine, fluorine, methyl, and methoxy; R9 is one of hydrogen and hydroxymethyl; R 10 It is one of hydrogen, chlorine, methyl and ethyl.

5. The preparation method according to claim 2, characterized in that: The solvent a includes a phosphate buffer solution; and / or the gelling agent includes one of ε-polylysine, chitosan, N-trimethyl chitosan chloride, O-carboxymethyl chitosan, hydrazide-modified hyaluronic acid, polyethyleneimine, and gelatin; and / or the solvent b includes one of a 2wt% acetic acid aqueous solution, physiological saline, and a phosphate buffer solution.

6. The preparation method according to claim 2, characterized in that: The solid content of the component A solution is 12wt%-50wt%; and / or, the solid content of the component B solution is 3.5wt%-30wt%; and / or, the volume ratio of the component A solution to the component B solution is (0.001-1):(0.001-1).

7. The preparation method according to claim 2, characterized in that: The reaction temperature of the mixed reaction is 0°C-45°C; and / or the pH is 6-12.

8. A polyethylene glycol hydrogel modified with an imidazolium salt structure obtained by the preparation method according to any one of claims 4 to 7.

9. An application of a polyethylene glycol hydrogel modified with an imidazole salt structure obtained by the preparation method according to any one of claims 4 to 7, characterized in that: This includes applications in any of the following areas: flexible electronic materials, electronic skin, biosensors, neural interfaces, or soft robotics.

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