A hydrogel containing AIE responsive groups, its preparation method and application

Abstract

This invention belongs to the field of fluorescent hydrogel preparation, and particularly relates to a hydrogel containing AIE-responsive groups, its preparation method, and its applications. This invention introduces AIE-responsive luminescent materials and organic polymers with conductor / semiconductor properties through a physicochemical crosslinking system, integrating AIE response and charge transport functions into a single hydrogel system to prepare a multifunctional composite hydrogel that can be in-situ molded, has a controllable structure, and expands its functionality. The hydrogel exhibits excellent mechanical, optical, and electrical properties, effectively broadening the application potential of hydrogels in flexible electronics, intelligent sensing, and other fields.

Description

Technical Field

[0001] This invention relates to the field of fluorescent hydrogel preparation, and more particularly to a hydrogel containing AIE responsive groups, its preparation method, and its application. Background Technology

[0002] Hydrogels are polymeric materials with a three-dimensional network structure that can absorb and retain large amounts of water (typically exceeding 90%) while maintaining a good solid form. Thanks to their tunable physicochemical properties (such as porosity, mechanical strength, and response speed) and the emergence of novel materials like nanocomposite hydrogels and dual-network hydrogels with advancements in materials science, their performance continues to improve, demonstrating enormous application potential in cutting-edge fields such as precision medicine, environmental remediation, and flexible electronics.

[0003] Fluorescent hydrogels are smart materials that combine fluorescent substances with a three-dimensional hydrogel network. They not only inherit the inherent high water content, biocompatibility, and stimulus responsiveness of hydrogels, but also endow the material with the ability to output optical signals, realizing an integrated "sensing-reporting" function of the material to the environment. However, traditional fluorescent materials in hydrogels generally suffer from aggregation-induced quenching (ACQ), meaning that fluorescence weakens or even disappears at high concentrations or in an aggregated state, which severely limits the practical application of fluorescent hydrogels. In 2001, Academician Tang Benzhong's team discovered aggregation-induced emission (AIE), the complete opposite of aggregation-induced quenching. In this phenomenon, fluorescent molecules in an aggregated state have restricted intramolecular motion, suppressing non-radiative transitions and thus promoting radiative transitions, leading to a significant enhancement of fluorescence. Introducing fluorescent groups with aggregation-induced emission effects into the gel network allows for the construction of stable and enhanced fluorescent gels at high concentrations, effectively overcoming the bottlenecks of traditional materials.

[0004] In the fields of soft robotics / actuators and flexible electronics, existing research attempts to use fluorescent hydrogels as the "skin" or actuators of robots. When these hydrogels deform, touch objects, or sense changes in their environment, their fluorescent signals change accordingly. This design endows robots with self-sensing capabilities, enabling them to provide feedback on their posture, pressure, or surrounding environment through optical signals, thus opening up possibilities for more intelligent interaction and adaptive motion. However, the conversion of these photoelectric signals has not yet been effectively achieved.

[0005] Therefore, how to construct continuous and stable conductive pathways and efficient AIE luminescence centers in the same hydrogel network remains a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0006] Based on this, the present invention provides a hydrogel containing AIE responsive groups, its preparation method, and its applications. The hydrogel integrates AIE fluorescence and conductivity functions through a physical-chemical cross-linking network. The multifunctional composite hydrogel provided by the present invention achieves in-situ molding, controllable cross-linking density, and expandable functionality, effectively broadening the application potential of hydrogels in flexible electronics, intelligent sensing, and other fields.

[0007] To achieve the above objectives, the present invention includes the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing a hydrogel containing AIE-responsive groups, comprising the following steps: S1: Add the acrylic acid derivative to water and mix thoroughly to obtain the base solution; S2: Add a luminescent material with AIE fluorescence response to the base solution in step S1 and stir until homogeneous; S3: Mix the organic polymer with conductive / semiconductor properties with a suitable solvent, stir until homogeneous at room temperature to 80 degrees Celsius, and slowly add the liquid prepared in step S2 while stirring. After the addition is complete, continue stirring at room temperature for 0.25 to 4 hours; wherein the organic polymer with conductive / semiconductor properties has a solubility in water of not less than 0.001 g / 100 g water. S4: At room temperature to 80 degrees Celsius, add filler to the mixed liquid obtained in step S3 and stir to disperse it evenly. S5: Initiator is uniformly added to the liquid in step S4 and injected into a mold or coated onto a substrate for reaction polymerization molding.

[0009] The acrylic acid derivative described in step S1 contains carbon-carbon double bonds, which can undergo free radical polymerization under the action of an initiator to form a covalently cross-linked three-dimensional network. The chemically cross-linked network is a permanent network structure with stronger stability, and the cross-linking density can be adjusted by changing the ratio of monomer to initiator. In step S2, the luminescent material is physically dispersed in an aqueous solution of the unpolymerized acrylic acid derivative. After the gel network is formed, the AIE molecules are confined within the network. In step S3, the organic polymer with conductive / semiconductor properties has a solubility in water of not less than 0.001 g / 100 g water, preferably not less than 0.1 g / 100 g water, and more preferably not less than 1 g / 100 g water. Organic polymers with conductive / semiconductor properties have conjugated π-bond structures or ionic conductive groups, and organic polymers with a certain solubility can be distributed in continuous aqueous channels, forming conductive pathways in the hydrogel network, thus giving the hydrogel conductive or semiconductor properties. Meanwhile, due to the hydrophobicity of AIE molecules, they preferentially aggregate in the hydrophobic region after addition. As the concentration of organic polymers in the liquid increases, molecular chains entangle around the AIE molecules, forming a cage-like structure to prevent AIE molecule migration and creating a controllable nano / micro aggregate structure. Since conductive / semiconductor organic polymers are prone to transient aggregation in aqueous phases, gradual diffusion can be achieved through slow addition and stirring. Furthermore, the addition of organic polymers and fillers further shears the AIE molecules, forming a multi-component homogeneous blend system. Different fillers possess different functional properties; adding fillers can functionalize the hydrogel, such as zinc oxide's antibacterial properties. Simultaneously, fillers can form hydrogen bonds and coordination bonds with acrylic derivatives and conductive organic polymers, serving as physical crosslinking points embedded in the network, increasing crosslinking density, optimizing pore size distribution, improving network regularity, and enhancing the mechanical properties of the hydrogel.

[0010] While existing technologies have developed physicochemically cross-linked hydrogels with excellent mechanical properties and attempted to achieve conductivity or fluorescence by introducing conductive polymers or aggregation-induced emission (AIE) molecules, introducing both into the same gel system still faces significant technical bottlenecks. This is mainly due to the fact that the broad-band absorption and charge transfer characteristics of conductive polymers easily quench the fluorescence of AIE molecules through photoinduced electron transfer or fluorescence resonance energy transfer, leading to a sharp decrease in luminescence efficiency. This invention first introduces AIE molecules to form initial aggregates, then slowly adds hydrophilic conductor / semiconductor organic polymers. This gently compresses the movable space of the hydrophobic AIE molecules, promoting the formation of structurally stable nano / micro aggregates. Simultaneously, the slow addition provides sufficient diffusion time for the organic polymers, allowing them to preferentially distribute in the continuous aqueous phase and avoiding direct encapsulation of AIE molecules that would cause fluorescence quenching. The scheme employs a multi-step synergistic approach, utilizing the hydrophobic nature of AIE molecules to distribute within the hydrophobic segment of the hydrogel. By selecting organic polymers with a certain solubility, a micro-phase separation design is achieved, creating spatial isolation between the functional components. The conductive / semiconductor organic polymers are mainly distributed in the continuous aqueous phase channels, forming conductive pathways that run through the inside and outside of the gel. The spontaneous microphase separation of the two effectively avoids direct contact and energy transfer between the conductive / semiconductor organic polymers and the AIE luminescent centers, thus preserving the fluorescence properties of AIE while maintaining the conductive / semiconductor properties.

[0011] Furthermore, by mass fraction, the base solution contains 10 parts of acrylic acid derivative, 0.1-40 parts of water, 0.0000001-10 parts of luminescent material with AIE fluorescence response, 0.0001-10 parts of organic polymer with conductor / semiconductor properties, 0.0001-10 parts of suitable solvent, and 0.001-1 part of initiator. Insufficient luminescent material will result in weak overall luminescence, while excessive luminescent material can easily cause concentration quenching, affecting the luminescence effect.

[0012] Further, the acrylic acid derivative may be selected from one or more of the following combinations: acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, polyethylene glycol methyl ether acrylate, methyl methacrylate, butyl acrylate, glycidyl methacrylate, acrylamide, isopropyl acrylamide, hydroxymethyl acrylamide, acryloyloxyethyltrimethylammonium chloride, methylene bisacrylamide, and sodium propylene sulfonate.

[0013] Furthermore, the luminescent material with AIE fluorescence response may be selected from one or more of the following combinations: hexaphenylthiophene (HPS) and its derivatives, tetraphenylethylene (TPE) and its derivatives, tetraphenylpyrazine (TPP) and its derivatives.

[0014] Furthermore, it may be selected from one or more combinations of the following: hexaphenylthiophene, tetraphenylethylene, tetraphenylpyrazine, tetrasulfonic hexaphenylthiophene, hexaphenylthiophene quaternary ammonium salt, tetracarboxylic acid hexaphenylthiophene, tetraphenylethylene quaternary ammonium salt, tetrasulfonic acid tetraphenylethylene, tetracarboxylic acid tetraphenylethylene, tetraphenylpyrazine quaternary ammonium salt, tetrasulfonic acid tetraphenylpyrazine, tetracarboxylic acid tetraphenylpyrazine, tricarboxylic acid hexaphenylthiophene, dicarboxylic acid hexaphenylthiophene, monocarboxylic acid hexaphenylthiophene, tricarboxylic acid tetraphenylethylene, dicarboxylic acid tetraphenylethylene, monocarboxylic acid tetraphenylethylene, tricarboxylic acid tetraphenylpyrazine, dicarboxylic acid tetraphenylpyrazine, monocarboxylic acid tetraphenylpyrazine.

[0015] Furthermore, the main chain monomers of the organic polymer having conductor / semiconductor properties may be selected from one or more combinations of the following: styrene sulfonate, styrene, benzene, aniline, naphthalene, anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, perylene, pyrrole, pyridine, pyrimidine, triazine, fluorene, thiofluorene, silanium, carbazole, thiophene, furan, thiazole, benzo[a]dithiophene, indene[a]dithiophene, thiophene[a]thiophene, indene[a]fluorene, phenyleneethylene, triphenylamine, benzo[a]thiadiazole, pyrrolopyrroledione, naphthimide, triphenylphosphine oxide, tetraphenylsilane, spirofluorene, spirosilanium, pyrazine, ethylenedioxythiophene, oxadiazole and their derivatives.

[0016] Furthermore, the following can be selected from one or more combinations of: 3,4-ethylenedioxythiophene, styrene sulfonate, naphthalene, phenyleneethylene, aniline, pyrrole, fluorene, and thiophene.

[0017] Furthermore, the weight-average molecular weight of the organic polymer with conductive / semiconductor properties is between 0.5 million and 2 million, preferably between 1 million and 2 million, and more preferably between 5 million and 2 million. Weight-average molecular weight is equal to mass-average molecular weight (MAM), and is a way of describing the molar mass of a polymer. It is the statistical average molecular weight per unit weight, and can be determined by methods such as light scattering, ultracentrifugation sedimentation rate, and gel permeation chromatography. A higher weight-average molecular weight generally results in better mechanical properties, but excessively high MAMs can affect solubility and increase the difficulty of preparing hydrogels.

[0018] Secondly, the present invention provides a hydrogel containing AIE-responsive groups.

[0019] Thirdly, the present invention provides a flexible structural material containing the hydrogel.

[0020] Fourthly, the present invention provides an application of the hydrogel or the flexible structural material described herein in cell scaffolds, biosensors, microfluidic chip substrate materials, flexible electronics and sensors, soft robots, electronic skin, wound dressings and wound repair, drug delivery systems, stretchable conductor strain sensors, flexible displays, organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic plasmon emitting diodes, and other optoelectronic devices.

[0021] Beneficial effects: Compared with the prior art, the hydrogel of the present invention introduces a luminescent material with AIE fluorescence response and an organic polymer with conductor / semiconductor properties on the basis of acrylic acid derivative polymer, thereby effectively improving the optical and electrical properties of the hydrogel and expanding its application potential. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the preparation process of the hydrogel containing AIE responsive groups in Example 1. Detailed Implementation

[0023] Hydrogels are a class of highly hydrophilic three-dimensional network gel structures. The higher the degree of cross-linking of the cross-linked network within the material, the lower the water absorption. The aggregated state of a hydrogel is neither a completely solid nor a completely liquid. The behavior of a solid is that it can maintain a certain shape and volume under certain conditions, while the behavior of a liquid is that solutes can diffuse or permeate through the hydrogel.

[0024] The inventors prepared a hydrogel that integrates conductivity and fluorescence by introducing AIE luminescent materials and organic polymers with conductor / semiconductor properties.

[0025] Furthermore, the present invention provides a flexible structural material containing the aforementioned hydrogel and its application in cell scaffolds, biosensors, microfluidic chip substrate materials, flexible electronics and sensors, soft robots, electronic skin, wound dressings and wound repair, drug delivery systems, stretchable conductor strain sensors, flexible displays, organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic plasmon emitting diodes, and other optoelectronic devices.

[0026] The hydrogel of the present invention can be prepared by the following method, specifically including the following steps: adding an acrylic acid derivative to water and mixing and stirring to obtain a base solution; adding a luminescent material with AIE fluorescence response to the base solution and stirring to obtain a uniform solution; mixing an organic polymer with conductor / semiconductor properties with a suitable solvent, stirring to obtain a uniform solution at room temperature to 80 degrees Celsius, slowly adding the liquid containing the luminescent material while stirring, and continuing to stir at room temperature for 0.25 to 4 hours after the addition is complete to obtain a mixed liquid of organic polymers; adding filler to the mixed liquid of organic polymers at room temperature to 80 degrees Celsius and stirring to disperse it uniformly to obtain a slurry; uniformly adding an initiator to the slurry and injecting it into a mold or coating it onto a substrate for reaction polymerization molding.

[0027] The acrylic acid derivative has a weight percentage range of 1 wt% to 99 wt%, preferably 10 wt% to 70 wt%, more preferably 15 wt% to 65 wt%, and even more preferably 15 wt% to 50 wt%. As a backbone, too low a content of the acrylic acid derivative will result in insufficient mechanical strength of the hydrogel, while too high a content will result in high brittleness, high hardness, and insufficient flexibility of the hydrogel.

[0028] The weight percentage ratio of the luminescent material with AIE fluorescence response to the acrylic acid derivative ranges from 0.000001 wt% to 100 wt%, preferably from 0.00001 wt% to 10 wt%, and more preferably from 0.001 wt% to 10 wt%. "AIE" stands for Aggregation-Induced Emission, a special photophysical phenomenon whose core mechanism is enhanced radiative transitions caused by restricted intramolecular motion. In the solid state, AIE materials weaken the conjugation effect through a three-dimensional framework structure, effectively suppressing non-radiative energy dissipation. AIE materials emit almost no light in dilute solutions, but the luminescence intensity can increase by tens of times after forming aggregates. Too little luminescent material results in weak overall luminescence, while too much luminescent material can easily cause concentration quenching, affecting the luminescence effect.

[0029] The weight percentage ratio of the organic polymer to the acrylic acid derivative ranges from 0.001 wt% to 100 wt%, preferably from 1 wt% to 100 wt%. Insufficient addition of the organic polymer can affect the conductive or semiconductor properties of the material.

[0030] The suitable solvent may be selected from one or more of the following combinations: water, methanol, ethanol, propanol, butanol, isopropanol, ethylene glycol, glycerol, acetic acid, methylamine, ethylamine, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, acetone, tetrahydrofuran, dioxane, pyrrole, furan, thiophene, and pyridine.

[0031] The organic polymers with conductive / semiconductor properties described in this invention have a LUMO-HOMO value ≤ 3.0 eV, preferably LUMO-HOMO ≤ 2.8 eV. Organic polymers with conductive / semiconductor properties represent a class of polymeric materials whose molecular structures contain conjugated long-chain structures. Delocalized π electrons on the double bonds can migrate along the molecular chain to form an electric current, giving the polymer structure inherent conductivity. In these conjugated polymers, the longer the molecular chain, the more π electrons, and the lower the electron activation energy, meaning electrons are more easily delocalized, resulting in better polymer conductivity. In this invention, the energy level structure of the organic material, specifically the triplet energy levels ET, HOMO, and LUMO, plays a crucial role. The corresponding energies of these energy levels significantly influence their conductivity or optical properties. Excessively high LUMO-HOMO values ​​result in poor conductivity and insulator properties. Furthermore, the magnitude of LUMO-HOMO and ET energies also affects the luminescence color of the material.

[0032] The filler material can be selected from one or more of the following combinations according to performance requirements: magnesium oxide, calcium oxide, magnesium chloride, calcium chloride, magnesium bromide, magnesium sulfate, magnesium nitrate, magnesium carbonate, magnesium acetate, magnesium hydroxide, calcium bromide, calcium sulfate, calcium nitrate, calcium carbonate, calcium acetate, calcium hydroxide, calcium lactate, calcium phosphate, calcium diphosphate, calcium hexametaphosphate, aluminum sulfate, aluminum hydroxide, aluminum oxide, aluminum carbonate, zinc oxide, zinc sulfate, zinc hydroxide, zinc carbonate, alginate, chitosan, cellulose and its derivatives, collagen, gelatin, polyethylene glycol and its derivatives, textile fibers, sodium chloride, lithium chloride, and potassium chloride. The total weight percentage of the filler material to the acrylic derivative ranges from 0.1 wt% to 1000 wt%.

[0033] The initiator, depending on the initiation principle, can be selected from one or more combinations of the following: azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutylamidine hydrochloride, azobisisopropylimidazoline, azobiscyanopentanoic acid, ammonium persulfate, potassium persulfate, sodium persulfate, tetramethylethylenediamine, sodium sulfite, ascorbic acid, ammonium sulfite, ferrous sulfate, and benzophenone. The weight percentage ratio of the initiator to the acrylic acid derivative ranges from 0.01 wt% to 10 wt%.

[0034] The present invention also relates to a composition comprising the hydrogel and an organic solvent.

[0035] The organic solvent may be selected from ester-based solvents: alkyl octanoate, alkyl sebacate, alkyl stearate, alkyl benzoate, alkyl phenylacetate, alkyl cinnamate, alkyl oxalate, alkyl maleate, alkyl lactone, alkyl oleate, etc. Octyl octanoate, diethyl sebacate, diallyl phthalate, and isononyl isononanoate are particularly preferred. The solvent may be used alone or as a mixture of two or more organic solvents.

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0037] Unless otherwise specified, all reagents and materials used in the following examples and comparative examples are commercially available.

[0038] Example 1 Mix 10g of acrylic acid and 40g of water until homogeneous, then add 0.005g of tetracarboxylate tetraphenylethylene and stir until homogeneous. Add 10g of ethylene glycol to 5g of commercially available poly(3,4-ethylenedioxythiophene) / poly(p-phenylene sulfonic acid) (PEDOT:PSS) solution and stir until homogeneous. Then add this mixture to the acrylic acid solution and continue stirring at room temperature for 1 hour. Next, add 0.5g of chitosan, 1g of calcium carbonate powder, and 13g of magnesium oxide powder sequentially and continue stirring, maintaining the temperature no higher than 60°C. After the reaction stops exothermic, add 0.001g of sodium persulfate and 0.001g of sodium sulfite to the solution separately and evenly. Then pour the solution into a mold and solidify to obtain the hydrogel of Example 1. The preparation process is as follows: Figure 1 As shown.

[0039] Example 2 Mix 8g of acrylic acid, 2g of acrylamide, and 40g of water until homogeneous, then add 0.005g of tricarboxylic acid tetraphenylethylene and stir until homogeneous. Add 6g of a DMF saturated solution of polyaniline to the acrylic acid solution and continue stirring at room temperature for 1 hour. Then add 0.1g of bacterial cellulose, 1g of calcium carbonate powder, and 10g of magnesium oxide powder in sequence and continue stirring while maintaining the temperature not exceeding 60°C. After the reaction stops exothermic, add 0.001g of ammonium persulfate evenly to the solution and then pour the solution into a mold to solidify and shape, obtaining the hydrogel of Example 2.

[0040] Example 3 Mix 10g of acrylic acid and 40g of water until homogeneous, then add 0.005g of tetrasulfonic acid hexaphenylthiophene and stir until homogeneous. Add 10g of glycerol to 5g of commercially available poly(3,4-ethylenedioxythiophene) / poly(p-phenylene sulfonic acid) (PEDOT:PSS) solution and stir until homogeneous. Then add the solution to the acrylic acid solution and continue stirring at room temperature for 1 hour. Then add 0.5g of carboxymethyl chitosan, 1g of calcium carbonate powder, and 13g of magnesium oxide powder in sequence and continue stirring while maintaining the temperature not higher than 60°C. After the reaction stops exothermic, add 0.001g of azobisisobutylamidine hydrochloride evenly to the solution and then pour the solution into a mold to solidify and shape, thus obtaining the hydrogel of Example 3.

[0041] Example 4 Mix 10g of acrylic acid and 40g of water until homogeneous, then add 0.005g of tetraphenylethylene tetrasulfonate and stir until homogeneous. Add 10g of ethylene glycol to 5g of commercially available poly(3,4-ethylenedioxythiophene) / poly(p-phenylene sulfonic acid) (PEDOT:PSS) solution and stir until homogeneous. Then add the solution to the acrylic acid solution and continue stirring at room temperature for 1 hour. Then add 0.5g of chitosan, 1g of calcium carbonate powder, 0.3g of lithium chloride, and 13g of magnesium oxide powder in sequence and continue stirring while maintaining the temperature not higher than 60°C. After the reaction stops exothermic, add 0.001g of benzophenone evenly to the solution and pour the solution into a mold. Cure the solution under light to obtain the hydrogel of Example 4.

[0042] Comparative Example 1 Mix 10g of acrylic acid and 40g of water until homogeneous, and continue stirring at room temperature for 1 hour. Then add 1g of calcium carbonate powder and 13g of magnesium oxide powder and continue stirring, maintaining the temperature no higher than 80℃. After the reaction stops exothermic, add 0.001g of sodium persulfate and 0.001g of sodium sulfite evenly to the solution, then pour the solution into a mold and solidify to obtain the hydrogel of Comparative Example 1.

[0043] The hydrogels prepared in Examples 1-4 and Comparative Example 1 were subjected to performance tests according to the following methods: 1. Tensile strength test Referring to GB / T 1040.1-2018, the test sample was made into a dumbbell-shaped specimen (20mm×5mm×2mm), and tested using a universal testing machine at a tensile rate of 100 mm / min until the specimen broke. The corresponding mechanical data were recorded.

[0044] 2. Fluorescence efficiency test The test sample was prepared into a thin film of uniform thickness (5 mm). Using a fluorescence spectrometer, the optimal excitation wavelength corresponding to the sample was selected, and the area of ​​its emission peak was measured. The relative fluorescence quantum efficiency of the sample and the reference tetraphenylethylene was calculated based on the emission peak area of ​​the reference.

[0045] 3. Conductivity test The test sample was fabricated into a rectangular thin film (30mm×10mm×2mm). A four-probe resistivity meter was used with the two parallel gold electrode spacing of 10 mm and the contact area A = 10×2 = 20 mm². The current and voltage data were recorded and the corresponding electronic conductivity was calculated.

[0046] Table 1. Comparative hydrogel performance test results of the examples

[0047] In summary, the test results in Table 1 show that the hydrogel of this invention exhibits improved mechanical, optical, and electrical properties. This invention prepares a hydrogel with excellent mechanical properties, combining electrical conductivity and fluorescence, by sequentially adding various raw materials with different functional properties through five steps. This hydrogel can be used as a flexible structural material in related fields.

[0048] The above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention. It is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the technical solution of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a hydrogel containing AIE responsive groups, characterized in that, Includes the following steps: S1: Add the acrylic acid derivative to water and mix thoroughly to obtain the base solution; S2: Add a luminescent material with AIE fluorescence response to the base solution in step S1 and stir until homogeneous; S3: Mix the organic polymer with conductive / semiconductor properties with a suitable solvent, stir until homogeneous at room temperature to 80 degrees Celsius, and slowly add the liquid prepared in step S2 while stirring. After the addition is complete, continue stirring at room temperature for 0.25 to 4 hours; wherein the organic polymer with conductive / semiconductor properties has a solubility in water of not less than 0.001 g / 100 g water. S4: At room temperature to 80 degrees Celsius, add filler to the mixed liquid obtained in step S3 and stir to disperse it evenly. S5: Initiator is uniformly added to the liquid in step S4 and injected into a mold or coated onto a substrate for reaction polymerization molding.

2. The method for preparing a hydrogel containing AIE responsive groups according to claim 1, characterized in that, By mass fraction, the base solution contains 10 parts of acrylic acid derivative, 0.1 to 40 parts of water, 0.0000001 to 10 parts of luminescent material, 0.0001 to 10 parts of organic polymer with conductor / semiconductor properties, 0.0001 to 10 parts of suitable solvent, and 0.001 to 1 part of initiator.

3. The method for preparing a hydrogel containing AIE responsive groups according to claim 1, characterized in that, The acrylic acid derivative may be selected from one or more of the following combinations: acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, polyethylene glycol methyl ether acrylate, methyl methacrylate, butyl acrylate, glycidyl methacrylate, acrylamide, isopropyl acrylamide, hydroxymethyl acrylamide, acryloyloxyethyltrimethylammonium chloride, methylene bisacrylamide, and sodium propylene sulfonate.

4. The method for preparing a hydrogel containing AIE responsive groups according to claim 1, characterized in that, The luminescent material with AIE fluorescence response may be selected from one or more of the following combinations: hexaphenylthiophene (HPS) and its derivatives, tetraphenylethylene (TPE) and its derivatives, tetraphenylpyrazine (TPP) and its derivatives.

5. The method for preparing a hydrogel containing AIE responsive groups according to claim 1, characterized in that, The organic polymers with conductive / semiconductor properties described herein may have their main chain monomers selected from one or more of the following combinations: styrene sulfonates, styrene, benzene, aniline, naphthalene, anthracene, phenanthrene, benzo[a]phenanthrene, pyrene, perylene, pyrrole, pyridine, pyrimidine, triazine, fluorene, thiofluorene, silanium, carbazole, thiophene, furan, thiazole, benzo[a]dithiophene, indene[a]dithiophene, thiophene[a]thiophene, indene[a]fluorene, phenyleneethylene, triphenylamine, benzo[a]thiadiazole, pyrrolopyrroledione, naphthimide, triphenylphosphine oxide, tetraphenylsilane, spirofluorene, spirosilanium, pyrazine, ethylenedioxythiophene, oxadiazole and their derivatives.

6. The method for preparing a hydrogel containing AIE responsive groups according to claim 5, characterized in that, The weight-average molecular weight of the organic polymers with conductive / semiconductor properties is between 0.5 million and 2 million.

7. A hydrogel containing AIE-responsive groups, characterized in that, It is prepared by the method described in any one of claims 1 to 6.

8. A composition, characterized in that, It contains the hydrogel and organic solvent as described in claim 7.

9. A flexible structural material, characterized in that, It comprises the hydrogel as described in claim 7 or the composition as described in claim 8.

10. The application of the flexible structural material as described in claim 9 in cell scaffolds, biosensors, microfluidic chip substrate materials, flexible electronics and sensors, soft robots, electronic skin, wound dressings and wound repair, drug delivery systems, stretchable conductor strain sensors, flexible displays, organic light-emitting diodes, organic photovoltaic cells, organic light-emitting cells, organic field-effect transistors, organic light-emitting field-effect transistors, organic lasers, organic spintronic devices, organic plasmon emitting diodes, and other optoelectronic devices.

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