A method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel

Abstract

The present invention provides a method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel, comprising the steps of: S1) ultrasonically mixing a macromolecular micelle crosslinker Brij‑100A with a monomeric acrylic acid; S2) adding a certain amount of thermal initiator ammonium persulfate and deionized water to step S1), and then ultrasonically applying the mixed solution; S3) adding a certain amount of conductive material to the MXene aqueous solution; S4) injecting the mixture into a glass mold and heating the mixture at 50°C for 10 hours to obtain a conductive hydrogel material. The material prepared by the present invention has excellent mechanical properties and can well meet the requirements of wearable sensors; it has high sensitivity and can accurately detect human body movements; and it has self-adhesive properties and can well conform to the human body; a strongly micelle-crosslinked hydrogel network is used as the main skeleton structure of the hydrogel material, and the abundant hydrophobic aggregation inside the micelles can effectively buffer external stress, thereby achieving the preparation of a highly tough hydrogel network.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive hydrogels, and in particular to a method for preparing a highly tough, highly sensitive, and self-adhesive conductive hydrogel. Background Art

[0002] In recent years, flexible wearable sensors have attracted much attention due to their wide applications in wearable electronic devices, bionic robots, artificial electronic skin, etc.

[0003] It is well known that when our human body is stimulated by the outside world, it converts the stimulation into bioelectronic signals. Inspired by this, many flexible electronic sensors based on various conductive materials have emerged in recent years.

[0004] Hydrogels are soft materials composed of a three-dimensional cross-linked polymer network and a large amount of water. Due to their excellent properties such as flexibility, water retention, tissue similarity, and biocompatibility, they have great applications in wearable sensors, electronic skin, and biomimetic robots.

[0005] These applications place higher demands on the sensitivity, stretchability, high strength and toughness, and self-adhesion of hydrogel sensors.

[0006] However, some hydrogel sensors often have low sensitivity or poor mechanical properties, which do not meet the development and application of our wearable sensors.

[0007] For example, the preparation method of conductive hydrogel in patent CN114605669A uses dioxygen crosslinking agent propylene glycol diglycidyl ester to prepare sodium carboxymethyl cellulose hydrogel; the prepared hydrogel is immersed in a weak acidic solution of aniline; and an oxidant is added to synthesize a conductive CMC / PAn composite hydrogel. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the present invention provides a method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel.

[0009] The technical solution of the present invention is: a method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel, which utilizes a strongly micellar cross-linked hydrogel network as the main skeleton structure of the hydrogel material, comprising the following steps:

[0010] S1) mixing the macromolecular micelle crosslinker Brij-100A with the monomer acrylic acid by sonication;

[0011] S2), adding a certain amount of thermal initiator ammonium persulfate and deionized water to step S1), and then ultrasonicating the mixed solution;

[0012] S3), adding a certain amount of conductive material and mixing with the MXene aqueous solution;

[0013] S4), then injecting it into a glass mold and heating it at 50° C. for 10 hours to obtain a conductive hydrogel material.

[0014] Preferably, the mass ratio of the monomer acrylic acid to the macromolecular micelle crosslinker Brij-100A is 5:1.

[0015] Preferably, the preparation method of the macromolecular micelle crosslinker Brij-100A is as follows:

[0016] After adding a certain amount of Brij-100 block polymer and granular potassium carbonate to a flask, vacuum the mixture at 80°C for two hours to remove water. After cooling, under inert atmosphere, add 200 ml of dry dichloromethane. Slowly add acryloyl chloride dissolved in dichloromethane to the flask under an ice-water bath.

[0017] The temperature was raised to room temperature and the reaction was allowed to proceed for 24 hours. The reaction solution was concentrated and precipitated in 500 ml of ether. The white precipitate was collected, rinsed with ether 2-3 times, and dried to obtain an acrylate-terminated Brij-100A block polymer. The synthetic chemical formula is as follows:

[0018]

[0019] Preferably, the conductive material is PEDOT:PSS or polyaniline PANI or polypyrrole Ppy.

[0020] Preferably, the concentration of the MXene aqueous solution is 5 mg / mL.

[0021] The beneficial effects of the present invention are:

[0022] 1. The material prepared by the present invention has excellent mechanical properties and can well meet the requirements of wearable sensors;

[0023] 2. The material prepared by the present invention is highly sensitive and can accurately detect human body movements. It also has self-adhesive properties and can better fit the human body.

[0024] 3. The present invention utilizes a strongly micellar cross-linked hydrogel network as the main skeleton structure of the hydrogel material. The abundant hydrophobic aggregation inside the micelles can effectively buffer external stress and achieve the preparation of a highly strong and tough hydrogel network.

[0025] 4. The addition of MXene in the present invention not only effectively improves the conductivity of the hydrogel, but also can be interconnected with PEDOT:PSS or GO through strong hydrogen bonding interactions, further enhancing the stability of the polymer network, which is beneficial to improving the mechanical strength of the material and the adhesion stability of the conductive material. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the PAAc / PEDOT:PSS / MXene conductive hydrogel network in Example 1 of the present invention;

[0027] Figure 2 Performance diagram of the PAAc / PEDOT:PSS / MXene conductive hydrogel in Example 1 of the present invention, including (a) stress-strain curve, (b) sensitivity, and (c) sensitivity when the MXene / PEDOT:PSS ratio is 3:0.4;

[0028] Figure 3 This is a graph showing the self-adhesion performance of the PAAc / PEDOT:PSS / MXene conductive hydrogel in Example 1 of the present invention;

[0029] Figure 4 This is the human body motion detection curve of PAAc / PEDOT:PSS / MXene conductive hydrogel in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0031] Example 1

[0032] This embodiment provides a method for preparing PAAc / PEDOT:PSS / Mxene conductive hydrogel

[0033] S1) Mix acrylic acid and Brij-100A in a mass ratio of 5:1, add 5 mg of ammonium persulfate and a certain amount of deionized water, and perform ultrasonication for 15 minutes;

[0034] S2), then 0.4 mL of PEDOT:PSS was mixed with 5 mg / mL of MXene aqueous solution and magnetically stirred for 1 min;

[0035] S3), adding the mixed solution of PEDOT:PSS and MXene to the sonicated solution in step S1) and stirring for 1 min;

[0036] S4), injecting the solution in step S3) into a glass mold (100 mm × 70 mm × 2 mm), and heating at 50 degrees for 10 hours to obtain PAAc / PEDOT:PSS / MXene conductive hydrogel.

[0037] The PAAc / PEDOT:PSS / MXene conductive hydrogel obtained above was wrapped with copper conductive tape, and then the hydrogel was adhered to the human body and connected to the hydrogel copper tape through an LCR meter to test the changes in resistance value under different actions.

[0038] Figure 1 Schematic diagram of the PAAc / PEDOT:PSS / MXene conductive hydrogel network in this embodiment;

[0039] Figure 2 Performance diagram of PAAc / PEDOT:PSS / MXene conductive hydrogel in this embodiment, including (a) stress-strain curve, (b) sensitivity, and (c) sensitivity when MXene / PEDOT:PSS ratio is 3:0.4;

[0040] Figure 3 This is a graph showing the self-adhesion performance of PAAc / PEDOT:PSS / MXene conductive hydrogel in this embodiment;

[0041] Figure 4 This is the human body motion detection curve of PAAc / PEDOT:PSS / MXene conductive hydrogel in this embodiment.

[0042] from Figure 1-4 As shown in the figure, a PAAc / PEDOT:PSS / MXene hydrogel with excellent mechanical properties, self-adhesion, and high sensitivity was prepared by using a strongly micellar cross-linked hydrogel network as the main framework of the hydrogel material and introducing MXene nanosheets and PEDOT:PSS. The corresponding strain sensor achieved a sensitivity coefficient of up to 20.86, a strain detection range of 2216%, and good adhesion, making it suitable for detecting various human movements.

[0043] Example 2

[0044] This embodiment provides a method for preparing PAAc / PANI / MXene conductive hydrogel

[0045] S1) Mix acrylic acid and Brij-100A in a mass ratio of 5:1, add 5 mg of ammonium persulfate and a certain amount of deionized water, and perform ultrasonication for 15 minutes;

[0046] S2), then dissolving 0.01-0.05 g of polyaniline in 0.4 mL of deionized water, and mixing with 5 mg / mL of MXene aqueous solution with magnetic stirring for 1 min;

[0047] S3), adding the mixed solution of polyaniline and MXene to the solution ultrasonicated in step S1) and stirring for 1 minute;

[0048] S4), injecting the solution in step S3) into a glass mold (100 mm×70 mm×2 mm), and heating at 50 degrees for 10 hours to obtain PAAc / PANI / Mxene conductive hydrogel.

[0049] The PAAc / PANI / Mxene conductive hydrogel obtained above was wrapped with copper conductive tape, and then the hydrogel was adhered to the human body and connected to the hydrogel copper tape through an LCR meter to test the change in resistance value under different actions.

[0050] Example 3

[0051] This embodiment provides a method for preparing PAAc / PANI / MXene conductive hydrogel

[0052] S1) Mix acrylic acid and Brij-100A in a mass ratio of 5:1, add 5 mg of ammonium persulfate and a certain amount of deionized water, and perform ultrasonication for 15 minutes;

[0053] S2), then dissolving 0.01-0.05 g of polypyrrole in 0.4 mL of deionized water and mixing with 5 mg / mL of MXene aqueous solution with magnetic stirring for 1 min;

[0054] S3), adding the mixed solution of polypyrrole and MXene to the sonicated solution in step S1) and stirring for 1 min;

[0055] S4), injecting the solution in step S3) into a glass mold (100 mm × 70 mm × 2 mm), and heating at 50 degrees for 10 hours to obtain PAAc / ppy / MXene conductive hydrogel.

[0056] The PAAc / ppy / MXene conductive hydrogel obtained above was wrapped with copper conductive tape, and then the hydrogel was adhered to the human body and connected to the hydrogel copper tape through an LCR meter to test the changes in resistance value under different actions.

[0057] The above embodiments and descriptions are only for explaining the principles and best embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, which shall fall within the scope of the invention to be protected.

Claims

1. A method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel, characterized in that: The method uses a strongly micellar cross-linked hydrogel network as the main skeleton structure of the hydrogel material, comprising the following steps: S1), mixing the macromolecular micelle crosslinker Brij-100A and the monomer acrylic acid by ultrasonication; the mass ratio of the monomer acrylic acid to the macromolecular micelle crosslinker Brij-100A is 5:1; S2), adding a certain amount of thermal initiator ammonium persulfate and deionized water to step S1), and then ultrasonically mixing the solution; S3), adding a certain amount of conductive material and mixing with the MXene aqueous solution; S4), then injecting it into a glass mold and heating it at 50° C. for 10 hours to obtain a conductive hydrogel material; The preparation method of the macromolecular micelle crosslinker Brij-100A is as follows: S101), adding a certain amount of Brij-100 block polymer and granular potassium carbonate into a flask, and then vacuuming at 80° C. for two hours to remove water; S102), after cooling to room temperature, under the protection of an inert atmosphere, adding a certain amount of dried dichloromethane, and slowly adding acryloyl chloride dissolved in dichloromethane into the flask under an ice-water bath; S103), heating to room temperature and reacting for 24 hours, concentrating the reaction solution and precipitating it in diethyl ether, collecting the white precipitate, washing it with diethyl ether 2-3 times, and drying it to obtain an acrylate-terminated Brij-100A block polymer, the synthetic chemical formula of which is as follows: 。 2. The method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel according to claim 1, wherein: In step S3), the conductive material is PEDOT:PSS or polyaniline PANI or polypyrrole Ppy.

3. The method for preparing a highly tough, highly sensitive, self-adhesive conductive hydrogel according to claim 2, wherein: In step S3), the concentration of the MXene aqueous solution is 5 mg / mL.

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