CN114381020A

CN114381020A - High-strain self-healing conductive hydrogel and preparation method thereof

Info

Publication number: CN114381020A
Application number: CN202210093755.5A
Authority: CN
Inventors: 陶圆圆; 谷倩倩; 彭丹; 李勇; 李东玮; 宫宏宇
Original assignee: New Material Institute of Shandong Academy of Sciences
Current assignee: New Material Institute of Shandong Academy of Sciences
Priority date: 2022-01-26
Filing date: 2022-01-26
Publication date: 2022-04-22
Anticipated expiration: 2042-01-26
Also published as: CN114381020B

Abstract

The invention discloses a high-strain self-healing conductive hydrogel and a preparation method thereof, belonging to the technical field of intelligent high polymer materials. The high-strain self-healing conductive hydrogel is prepared by taking methacrylic acid and polyethylene glycol methacrylate as monomers, N, N-methylene bisacrylamide as a cross-linking agent, potassium persulfate as an initiator, tetramethylethylenediamine as a catalyst, a conductive substance which is poly (3, 4-ethylene-dioxythiophene) -poly (styrene sulfonate) and a reinforcing agent which is carboxymethyl cellulose under an oxygen-removing condition. The conductive hydrogel prepared by the raw materials has good conductive performance and flexibility, and meanwhile, the conductive hydrogel has strong adhesive force and can be self-healed, and the conductive hydrogel can be used for constructing a flexible sensor with higher sensing sensitivity.

Description

High-strain self-healing conductive hydrogel and preparation method thereof

Technical Field

The invention relates to a high-strain self-healing conductive hydrogel and a preparation method thereof, belonging to the technical field of intelligent high polymer materials.

Background

The hydrogel is a soft and wet material with a special three-dimensional network and the water content of about 90 percent, and has the advantages of adjustable hydrogel performance, good biocompatibility and the like by selecting different three-dimensional network structures, thereby being widely concerned in the field of bioelectronics. The conductive polymer is a flexible material with hydrogel mechanical properties and conductive properties of conductive materials, and has wide application in the fields of intelligent high polymer materials, such as tissue engineering, medical electrodes, flexible electronic skin, biosensing and the like. The preparation of the conductive hydrogel is to fill conductive materials in a three-dimensional network structure of the hydrogel, wherein the conductive materials comprise conductive polymers, carbon nanotubes, metal ions and the like, the filled conductive materials are different, and the properties of the conductive polymers are different.

In recent years, the conductive hydrogel is widely applied to the field of wearable electronic devices, including wearable electronic sensing, biomedicine, flexible wearable energy storage devices and the like. However, the conductive hydrogel serving as a wearable electronic device has some limitations, such as low adhesion between the conductive hydrogel and the skin, limited conductive performance, flexibility, self-healing performance and strain range, and incapability of retaining water for a long time, and the like, and the problems are all urgently needed to be solved by the conductive hydrogel serving as a novel material.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the high-strain self-healing conductive hydrogel and the preparation method thereof, so that the prepared conductive hydrogel has good conductivity and flexibility, and meanwhile, the conductive hydrogel has strong adhesion and can be self-healed, and can be used for constructing a flexible sensor with higher sensing sensitivity.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a preparation method of high-strain self-healing conductive hydrogel, which comprises the following steps:

1) dispersing the reinforcing agent in a solvent, and stirring and dissolving uniformly to obtain a system A;

2) adding a monomer into the system A prepared in the step 1) under a protective atmosphere, and uniformly stirring to obtain a system B;

3) adding a cross-linking agent into the system B prepared in the step 2) under a protective atmosphere, and uniformly stirring to obtain a system C;

4) adding a conductive filler into the system C prepared in the step 3) under a protective atmosphere, and uniformly stirring to obtain a system D;

5) adding an initiator into the system D prepared in the step 4) under a protective atmosphere, adding a catalyst after uniformly stirring, and uniformly stirring again to obtain a system E;

6) standing and aging the system E obtained in the step 5) to obtain the high-strain self-healing conductive hydrogel;

the monomers in the step 2) are acrylic acid and polyethylene glycol methacrylate.

Further, the reinforcing agent in the step 1) is carboxymethyl cellulose, and the using amount of the reinforcing agent, the monomer, the cross-linking agent, the conductive filler, the initiator and the catalyst is 0.1-5% of the total mass of the reinforcing agent, the monomer, the cross-linking agent, the conductive filler, the initiator and the catalyst.

Further, the amount of the monomer in the step 2) is 15-50% of the total mass of the reinforcing agent, the monomer, the cross-linking agent, the conductive filler, the initiator and the catalyst, and the molar mass ratio of the acrylic acid to the polyethylene glycol methacrylate is 1: 5-1: 20.

Further, in the step 3), the cross-linking agent is N, N-methylene bisacrylamide, and the using amount of the cross-linking agent is 0.1-0.5% of the mass of the monomer.

Further, in the step 4), the conductive filler is poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid) (PEDOT: PSS), and the amount of the conductive filler is 0.5-5% of the mass of the monomer.

Further, in the step 5), the initiator is potassium persulfate, and the using amount of the initiator is 0.2-1% of the mass of the monomer.

Further, in the step 5), the catalyst is tetramethylethylenediamine, and the using amount of the catalyst is 0.01-0.04% of the mass of the monomer.

Further, the standing and aging time in the step 6) is 1-20 days.

Further, the solvent in step 1) is deionized water.

The invention also provides the high-strain self-healing conductive hydrogel prepared by the preparation method.

The invention discloses the following technical effects:

1) the monomer acrylic acid and the polyethylene glycol methyl methacrylate are used for constructing the three-dimensional network structure of the hydrogel, multiple hydrogen bond actions can be formed with water after gelling, the functional failure of the hydrogel caused by water evaporation can be relieved to a certain extent, and the carboxymethyl cellulose is used as a reinforcing agent of the hydrogel, so that the multiple hydrogen bond actions can be formed with the three-dimensional network structure of the polymer, the strength of the hydrogel is increased, and the strain force is improved. The self-healing can be realized by cutting the surface of the hydrogel due to the strong hydrogen bond effect in the conductive hydrogel. The conductive material is PEDOT, PSS can form stronger interaction force with the three-dimensional network of the hydrogel and the reinforcing agent, so that the hydrogel has stronger conductivity.

2) The conductive hydrogel prepared by the invention has good conductivity and flexibility, and meanwhile, the conductive hydrogel has strong adhesion and can be self-healed, and can be used for constructing a flexible sensor with higher sensing sensitivity.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a diagram of a sample of the electrically conductive hydrogel prepared in example 1;

FIG. 2 is a diagram showing the deformation of the conductive hydrogel prepared in example 1 by the action of hand;

FIG. 3 is a diagram showing the deformation of the conductive hydrogel prepared in example 1 under the action of a texture analyzer.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The raw materials used in the examples of the present invention are commercially available.

The technical solution of the present invention is further illustrated by the following examples.

Example 1

A preparation method of high-strain self-healing conductive hydrogel comprises the following steps:

1) dissolving 50mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 5 hours, and fully dissolving and mixing to obtain a system A;

2) adding 0.1g of acrylic acid monomer and 0.9g of polyethylene glycol methacrylic acid monomer into the system A prepared in the step 1) under the nitrogen protection atmosphere, and uniformly stirring and mixing to obtain a system B;

3) adding 4mg of N, N-methylene bisacrylamide into the system B prepared in the step 2) under the nitrogen protection atmosphere, and uniformly stirring to obtain a system C;

4) under a nitrogen atmosphere, 20mg of PEDOT: adding PSS into deionized water to prepare PEDOT with the mass concentration of 1.5%: PSS water system, taking 1.33g PEDOT: adding the PSS water system into the system C prepared in the step 3), and uniformly stirring to obtain a system D;

5) adding 3mg of potassium persulfate into the system D prepared in the step 4) under the nitrogen protection atmosphere, uniformly stirring, adding 20 mu L of catalyst tetramethyl ethylenediamine, and uniformly stirring to obtain a system E;

6) pouring the system E prepared in the step 5) into a polytetrafluoroethylene mold, standing, and aging for 3 days to obtain the high-strain self-healing conductive hydrogel.

The high strain self-healing electrically conductive hydrogel prepared in example 1 was subjected to performance testing, and the results were as follows:

FIG. 1 shows the gel sample of the mixed system E after 3 days of aging, which is a mature conductive hydrogel sample with stable shape and uniform color.

FIG. 2 shows that the hands interact with the conductive hydrogel, the hydrogel has strong interaction force with the hands, tensile force is applied to the hydrogel, the hydrogel is stretched and deformed, the tensile force is removed, and the hydrogel is restored to the original shape, which indicates that the conductive hydrogel has high strain.

Example 2

1) dissolving 25mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 4 hours, and fully dissolving and mixing to obtain a system A;

2) adding 0.05g of acrylic acid monomer and 0.95g of polyethylene glycol methacrylic acid monomer into the system A prepared in the step 1) under the nitrogen protection atmosphere, and stirring and mixing uniformly to obtain a system B;

4) under a nitrogen atmosphere, 20mg of PEDOT: adding PSS into deionized water to prepare a PEDOT (Polytetrafluoroethylene-PSS) water system with the mass concentration of 1.5%, adding 1.33g of the PEDOT (Polytetrafluoroethylene-PSS) water system into the system C prepared in the step 3), and uniformly stirring to obtain a system D;

5) adding 4mg of potassium persulfate into the system D prepared in the step 4) under the nitrogen protection atmosphere, uniformly stirring, adding 25 mu L of catalyst tetramethylethylenediamine, and uniformly stirring to obtain a system E;

6) pouring the system E prepared in the step 5) into a polytetrafluoroethylene mold, standing, and aging for 5 days to obtain the high-strain self-healing conductive hydrogel.

Example 3

1) dissolving 75mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 3 hours, and fully dissolving and mixing to obtain a system A;

3) adding 3mg of N, N-methylene bisacrylamide into the system B prepared in the step 2) under the nitrogen protection atmosphere, and uniformly stirring to obtain a system C;

5) adding 4mg of potassium persulfate into the system D prepared in the step 4) under the nitrogen protection atmosphere, uniformly stirring, adding 35 mu L of catalyst tetramethylethylenediamine, and uniformly stirring to obtain a system E;

6) pouring the system E prepared in the step 5) into a polytetrafluoroethylene mold, standing, and aging for 7 days to obtain the high-strain self-healing conductive hydrogel.

Example 4

1) dissolving 100mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 5 hours, and fully dissolving and mixing to obtain a system A;

2) adding 0.15g of acrylic acid monomer and 0.85g of polyethylene glycol methacrylic acid monomer into the system A prepared in the step 1) under the nitrogen protection atmosphere, and stirring and mixing uniformly to obtain a system B;

3) under the protection of nitrogen, adding 5mg of N, N-methylene bisacrylamide into the system B prepared in the step 2), and uniformly stirring to obtain a system C;

4) under the protection of nitrogen, 20mg of PEDOT: PSS is added into deionized water to prepare a PEDOT: PSS water system with the mass concentration of 1.5%, and 1.33g of PEDOT: adding the PSS water system into the system C prepared in the step 3), and uniformly stirring to obtain a system D;

5) under the protection of nitrogen, 6mg of potassium persulfate is dissolved and added into the system D prepared in the step 4), after uniform stirring, 50 mu L of catalyst tetramethylethylenediamine is added, and uniform stirring is carried out, so as to obtain a system E;

6) pouring the system E prepared in the step 5) into a polytetrafluoroethylene mold, standing, and aging for 14 days to obtain the high-strain self-healing conductive hydrogel.

Example 5

1) dissolving 116mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 5 hours, and fully dissolving and mixing to obtain a system A;

4) under the protection of nitrogen, 50mg of PEDOT: PSS is added into deionized water to prepare a PEDOT: PSS water system with the mass concentration of 1.5%, and 3.32g of PEDOT: adding the PSS water system into the system C prepared in the step 3), and uniformly stirring to obtain a system D;

5) adding 5mg of potassium persulfate into the system D prepared in the step 4) under the nitrogen protection atmosphere, uniformly stirring, adding 25 mu L of catalyst tetramethylethylenediamine, and uniformly stirring to obtain a system E;

Example 6

1) dissolving 2mg of carboxymethyl cellulose in 5mL of deionized water, stirring for 3 hours, and fully dissolving and mixing to obtain a system A;

3) under the protection of nitrogen, adding 1mg of N, N-methylene bisacrylamide into the system B prepared in the step 2), and uniformly stirring to obtain a system C;

4) under the nitrogen protection atmosphere, adding 5mg of PEDOT (PEDOT)/PSS (PSS) into deionized water to prepare a PEDOT/PSS water system with the mass concentration of 1.5%, adding 0.33g of PEDOT/PSS water system into the system C prepared in the step 3), and uniformly stirring to obtain a system D;

5) adding 2mg of potassium persulfate into the system D prepared in the step 4) under the nitrogen protection atmosphere, uniformly stirring, adding 25 mu L of catalyst tetramethylethylenediamine, and uniformly stirring to obtain a system E;

6) pouring the system E prepared in the step 5) into a polytetrafluoroethylene mold, standing, and aging for 1 day to prepare the high-strain self-healing conductive hydrogel.

Performance testing

First, conductivity test

The electrical conductivity of the resulting hydrogel was measured by a digital source meter (KEITHLEY2400) at a potential of 2.1V, test temperature 25 ℃. The conductivity of the hydrogel materials of examples 1-6 was evaluated, and the test results are shown in Table 1.

Table 1 conductivity test results

As can be seen from the data in table 1, the conductive hydrogel prepared in the example of the present invention has excellent conductive performance, and the conductivity can reach 3.0S/cm, which indicates that the conductive polymer PEDOT: the PSS, the polymer and the carboxymethyl cellulose form a three-dimensional network structure with high conductivity.

Second, compression performance test

For the compression experiment, the hydrogel prepared in example 1 was subjected to cyclic compression measurement at room temperature by a extensometer at a compression rate of 5mm/min, and as shown in fig. 3, the hydrogel was compressed to 90% of the initial strain and returned to the initial state 1min after the pressure was removed, and it was seen that it could withstand a large compressive force and rapidly returned to the initial state.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. A preparation method of high-strain self-healing conductive hydrogel is characterized by comprising the following steps:

2. The method according to claim 1, wherein the reinforcing agent in step 1) is carboxymethyl cellulose, and the amount of the reinforcing agent, the monomer, the crosslinking agent, the conductive filler, the initiator and the catalyst is 0.1-5% of the total mass.

3. The method according to claim 1, wherein the amount of the monomer used in step 2) is 15 to 50% of the total mass of the reinforcing agent, the monomer, the crosslinking agent, the conductive filler, the initiator and the catalyst, and the molar mass ratio of acrylic acid to polyethylene glycol methacrylate is 1:5 to 1: 20.

4. The method according to claim 1, wherein the crosslinking agent in step 3) is N, N-methylenebisacrylamide in an amount of 0.1 to 0.5% by mass based on the mass of the monomer.

5. The method as claimed in claim 1, wherein the conductive filler in step 4) is poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid) in an amount of 0.5 to 5% by mass based on the mass of the monomer.

6. The method according to claim 1, wherein the initiator in step 5) is potassium persulfate, and the amount of the initiator is 0.2-1% of the mass of the monomer.

7. The method of claim 1, wherein the catalyst in step 5) is tetramethylethylenediamine, and the amount of the tetramethylethylenediamine is 0.01 to 0.04% by mass of the monomer.

8. The method according to claim 1, wherein the standing aging time in the step 6) is 1 to 20 days.

9. The method of claim 1, wherein the solvent in step 1) is deionized water.

10. The high-strain self-healing conductive hydrogel prepared by the preparation method according to any one of claims 1 to 9.