Graphene oxide / chitosan / acrylamide composite hydrogel and preparation method thereof
By modifying graphene oxide and chitosan and co-preparing composite hydrogels with acrylamide, the problem of poor dispersion of inorganic materials in conductive hydrogels is solved, high mechanical properties and excellent conductivity and responsiveness are achieved, and its performance in various application fields is improved.
Patent Information
- Application Number
- CN202411803394.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-03-14
AI Technical Summary
The poor dispersion of inorganic materials in conductive hydrogels leads to insufficient mechanical properties, limiting their reliability during wear or implantation.
By modifying graphene oxide and chitosan to form a premix, and co-preparing graphene oxide/chitosan/acrylamide composite hydrogel with acrylamide to improve its mechanical properties.
It realizes the high mechanical properties of conductive hydrogels, excellent conductivity, conductive responsiveness and mechanical performance stability, and improves its application performance in sensors, capacitors, fluid control and intelligent machinery.
Abstract
Description
Technical Field
[0001] The invention belongs to the field of polymer material preparation, and specifically relates to a composite hydrogel and a preparation method thereof. Background Art
[0002] Hydrogel is a super absorbent polymer composed of poly (N-isopropylacrylamide), polyacrylamide, polyacrylic acid (salt), etc., which is lightly cross-linked and contains strong water-absorbing groups and has a three-dimensional network structure. Hydrogel can absorb liquids that are hundreds to thousands of times heavier than its own weight, and the absorbed liquid is not released or released in very small amounts under pressure. It has excellent gel stability and can be used as a good carrier for functional soft materials. Polyacrylamide hydrogel has become an important branch in the field of hydrogels due to its unique physical and chemical properties and wide range of applications.
[0003] Chitosan is a natural alkaline polysaccharide with good biocompatibility and biodegradability. It can improve the antibacterial properties and tensile properties of hydrogels, promote wound healing, enhance water absorption, provide adhesion and improve thermal stability. These properties make chitosan an important multifunctional material in the field of hydrogels. In recent years, conductive hydrogels, as a family of smart hydrogels, have gradually entered people's field of vision. Polymer-based conductive hydrogels are composed of two components: conductive materials and hydrogels. The conductive materials include graphene, carbon nanotubes, polyaniline, polypyrrole, polythiophene, etc. Therefore, conductive hydrogels have unique properties of two components. However, the tensile properties of conductive hydrogels and human tissues are poorly matched, which hinders their reliability during wear or implantation. The low stretchability of hydrogels is usually attributed to the uneven chemical cross-linking network and the lack of an effective energy dissipation network. Therefore, improving the mechanical properties of conductive hydrogels is the focus of scientific researchers. For example, CN113278188 discloses a method for preparing a high-strength and high-toughness strain-responsive graphene oxide conductive hydrogel, which uses chitosan, graphene oxide and acrylamide to prepare a hydrogel with both strength and toughness. However, it requires the preparation of hyperbranched siloxane as a cross-linking agent, and the process is cumbersome and costly.
[0004] At present, the poor dispersibility of inorganic materials in conductive hydrogels is a problem faced by researchers. How to improve the dispersibility of inorganic materials in inorganic conductive hydrogels and the mechanical properties of hydrogels is the focus of related research. Summary of the invention
[0005] The purpose of the present invention is to provide a conductive hydrogel with high mechanical properties and a preparation method thereof. In view of the poor mechanical properties of conventional conductive hydrogels, graphene oxide and chitosan grafted with double bonds are first prepared, then the two are formed into a premix, and finally the premix is prepared with acrylamide to prepare a graphene oxide / chitosan / acrylamide composite hydrogel, which can be practically applied in the fields of sensors, capacitors, fluid control, intelligent machinery, etc.
[0006] To achieve the above object, the present invention adopts the following technical solution:
[0007] 1. A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel, comprising the following steps:
[0008] (1) Modification of graphene oxide: dispersing graphene oxide in an ethanol aqueous solution containing a double-bond silane coupling agent, heating and stirring, and washing and drying with deionized water and ethanol after the reaction is completed to obtain graphene oxide modified with a silane coupling agent;
[0009] (2) Modification of chitosan: chitosan and acrylic acid are added to water and stirred, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is added and stirred to react under nitrogen protection. After the reaction is completed, the product is dialyzed and freeze-dried to obtain double-bond modified chitosan;
[0010] (3) Premixing chitosan and graphene oxide: adding modified chitosan and graphene oxide modified with a silane coupling agent into an acetic acid aqueous solution, heating and stirring, to obtain a premix of chitosan and graphene oxide;
[0011] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: acrylamide, an initiator, a crosslinking agent, and an acetic acid aqueous solution are added to the above premix to react and obtain a graphene oxide / chitosan / acrylamide composite hydrogel.
[0012] Furthermore, in the step (1), the mass ratio of graphene oxide to silane coupling agent is 1:1-10.
[0013] Furthermore, the reaction temperature in step (1) is 60-80°C, and the reaction time is 5-24h.
[0014] Furthermore, the concentration of the ethanol aqueous solution in step (1) is 1-5 vol%.
[0015] Furthermore, the silane coupling agent containing a double bond in step (1) is one or more of 3-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane.
[0016] Furthermore, in the step (2), the mass ratio of chitosan, acrylic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and water is 1-5:1-5:1-5:100-300.
[0017] Furthermore, the reaction temperature in step (2) is 20-40° C., and the reaction time is 1-5 h.
[0018] Furthermore, in the step (3), the mass ratio of the modified chitosan, the graphene oxide modified by the silane coupling agent, and the acetic acid aqueous solution is 1-5:0.005-0.1:1-10.
[0019] Furthermore, the mixing temperature in step (3) is 40-80° C., and the mixing time is 1-5 h.
[0020] Furthermore, the deacetylation degree of chitosan in step (3) is 85-95%.
[0021] Furthermore, the concentration of the acetic acid aqueous solution in steps (3) and (4) is 1-5 vol%.
[0022] Furthermore, in step (4), the mass ratio of the premix, acrylamide, initiator, crosslinking agent and acetic acid aqueous solution is 1-10:10-30:0.01-0.1:0.1-1:10-100.
[0023] Furthermore, the reaction temperature in step (4) is 40-60° C., and the reaction time is 12-14 h; the initiator in step (4) is one or more of ammonium persulfate, potassium persulfate, and sodium persulfate; and the crosslinking agent is N,N-methylenebisacrylamide.
[0024] A graphene oxide / chitosan / acrylamide composite hydrogel is prepared by the above preparation method.
[0025] The significant advantages of the present invention are:
[0026] (1) The present invention first uses a silane coupling agent to modify the surface of graphene oxide to obtain graphene oxide containing double bonds, and then uses acrylic acid and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) to modify chitosan to obtain double-bond modified chitosan; then it reacts with acrylamide to form a hydrogel with excellent mechanical properties.
[0027] (2) The present invention premixes chitosan and graphene oxide, thereby improving the compatibility of the two and the subsequent dispersibility in acrylamide, and further improving the mechanical properties of the hydrogel.
[0028] (3) The composite hydrogel prepared by the present invention not only has excellent mechanical properties, but also has excellent electrical conductivity, conductive responsiveness and mechanical property stability. DETAILED DESCRIPTION
[0029] In order to have a clearer understanding of the above-mentioned technical route and beneficial effects of the present invention, the technical scheme of the present invention is further explained below in combination with specific implementation methods, wherein the tensile properties are tested on a universal tensile testing machine.
[0030] Example 1
[0031] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0032] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 12 h. After the reaction was completed, the mixture was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0033] (2) Modification of chitosan: 2 g of chitosan and 4 g of acrylic acid were added to 200 ml of water and stirred, and then 4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0034] (3) Premixing of chitosan and graphene oxide: 2 g of modified chitosan and 0.05 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0035] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0036] After testing, the tensile property of the composite hydrogel prepared in Example 1 was 0.65 MPa.
[0037] Example 2
[0038] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0039] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 70° C. and stirred for 12 h. After the reaction was completed, it was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0040] (2) Modification of chitosan: 2 g chitosan and 5 g acrylic acid were added to 200 ml water and stirred, and then 5 g 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0041] (3) Premixing of chitosan and graphene oxide: 2 g of modified chitosan and 0.1 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 80° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0042] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 24 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0043] After testing, the tensile property of the composite hydrogel prepared in Example 2 was 0.70 MPa.
[0044] Example 3
[0045] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0046] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 24 h. After the reaction was completed, it was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0047] (2) Modification of chitosan: 2 g chitosan and 3 g acrylic acid were added to 200 ml water and stirred, and then 3 g 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0048] (3) Premixing of chitosan and graphene oxide: 2 g of modified chitosan and 0.03 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 60° C. and stirred for 3 h to obtain a premix of chitosan and graphene oxide;
[0049] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 12 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0050] After testing, the tensile property of the composite hydrogel prepared in Example 3 was 0.60 MPa.
[0051] Example 4
[0052] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0053] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.8 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 12 h. After the reaction was completed, it was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0054] (2) Modification of chitosan: 2 g of chitosan and 4 g of acrylic acid were added to 200 ml of water and stirred, and then 4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0055] (3) Premixing of chitosan and graphene oxide: 2 g of modified chitosan and 0.05 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0056] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 15 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 20 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0057] After testing, the tensile property of the composite hydrogel prepared in Example 4 was 0.68 MPa.
[0058] Example 5
[0059] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0060] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 12 h. After the reaction was completed, the mixture was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0061] (2) Modification of chitosan: 2 g of chitosan and 4 g of acrylic acid were added to 200 ml of water and stirred, and then 4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0062] (3) Premixing of chitosan and graphene oxide: 1 g of modified chitosan and 0.05 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0063] (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 30 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0064] After testing, the tensile property of the composite hydrogel prepared in Example 5 was 0.57 MPa.
[0065] Comparative Example 1
[0066] This comparative example has the same feeding order and preparation steps as Example 1, except that the graphene oxide is not modified by the silane coupling agent. The specific steps are as follows:
[0067] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0068] (1) Modification of chitosan: 2 g of chitosan and 4 g of acrylic acid were added to 200 ml of water and stirred, and then 4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25° C. under nitrogen protection for 2 h. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0069] (2) Premixing of chitosan and graphene oxide: 2 g of modified chitosan and 0.05 g of graphene oxide were added to 5 g of acetic acid aqueous solution (2 vol%), heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0070] (3) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60°C and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0071] After testing, the tensile property of the composite hydrogel prepared in Comparative Example 1 was 0.43 MPa.
[0072] Comparative Example 2
[0073] This comparative example has the same feeding order and preparation steps as Example 1, except that chitosan is not double-bond modified. The specific steps are as follows:
[0074] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0075] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 12 h. After the reaction was completed, the mixture was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0076] (2) Premixing of chitosan and graphene oxide: 2 g of chitosan and 0.05 g of graphene oxide modified with a silane coupling agent were added to 5 g of an acetic acid aqueous solution (2 vol%), heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0077] (3) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60°C and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0078] After testing, the tensile property of the composite hydrogel prepared in Comparative Example 2 was 0.40 MPa.
[0079] Comparative Example 3
[0080] This comparative example has the same feeding order and preparation steps as Example 1, except that graphene oxide and chitosan are not double-bond modified. The specific steps are as follows:
[0081] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0082] (1) Premixing chitosan and graphene oxide: 2 g chitosan and 0.05 g graphene oxide were added to 5 g acetic acid aqueous solution, heated to 70° C. and stirred for 2 h to obtain a premix of chitosan and graphene oxide;
[0083] (2) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 20 g acrylamide, 0.05 g ammonium persulfate, 0.5 g N,N-methylenebisacrylamide, and 30 g acetic acid aqueous solution (2 vol%) were added to the above premix, heated to 60° C. and reacted for 16 h to obtain graphene oxide / chitosan / acrylamide composite hydrogel.
[0084] After testing, the tensile property of the composite hydrogel prepared in Comparative Example 3 was 0.32 MPa.
[0085] Comparative Example 4
[0086] This comparative example has the same feeding order and preparation steps as Example 1, except that the premixing step of modified graphene oxide and chitosan is not performed. The specific steps are as follows:
[0087] A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel specifically comprises the following steps:
[0088] (1) Modification of graphene oxide: 0.1 g of graphene oxide was dispersed in 100 ml of an ethanol aqueous solution (2 vol%) containing 0.5 g of 3-methacryloxypropyltrimethoxysilane, heated to 60° C. and stirred for 12 h. After the reaction was completed, the mixture was washed and dried with deionized water and ethanol to obtain graphene oxide modified with a silane coupling agent;
[0089] (2) Modification of chitosan: 2 g of chitosan and 4 g of acrylic acid were added to 200 ml of water and stirred, and then 4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added. The mixture was stirred and reacted at 25°C for 2 h under nitrogen protection. After the reaction, the product was dialyzed and freeze-dried to obtain double-bond modified chitosan.
[0090] (3) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: 2 g of modified chitosan, 0.05 g of graphene oxide modified with a silane coupling agent, 20 g of acrylamide, 0.05 g of ammonium persulfate, 0.5 g of N,N-methylenebisacrylamide, and 35 g of acetic acid aqueous solution (2 vol%) were added into a flask, and the mixture was heated to 60 °C and reacted for 16 h to obtain a graphene oxide / chitosan / acrylamide composite hydrogel.
[0091] After testing, the tensile property of the composite hydrogel prepared in Comparative Example 4 was 0.52 MPa.
[0092] It can be seen from Comparative Examples 1-3 that the double bond modification of graphene oxide and chitosan improves the compatibility and cross-linking degree of the above components between the acrylamide hydrogel components, and improves the mechanical properties; it can be seen from Comparative Example 4 that premixing the two can first carry out a certain degree of grafting reaction, which improves the overall compatibility and mechanical properties compared to blending all the components together.
[0093] In addition, in addition to the most important tensile properties, the toughness, deformation recovery rate after repeated stretching and resistance strain responsiveness of the hydrogels of Examples 1-5 are also improved to varying degrees compared with Comparative Examples 1-3.
[0094] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.
Claims
1. A method for preparing a graphene oxide / chitosan / acrylamide composite hydrogel, comprising the following steps: (1) Modification of graphene oxide: dispersing graphene oxide in an ethanol aqueous solution containing a double-bond silane coupling agent, heating and stirring, and washing and drying with deionized water and ethanol after the reaction is completed to obtain graphene oxide modified with a silane coupling agent; (2) Modification of chitosan: chitosan and acrylic acid are added to water and stirred, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is added and stirred to react under nitrogen protection. After the reaction is completed, the product is dialyzed and freeze-dried to obtain double-bond modified chitosan; (3) Premixing chitosan and graphene oxide: adding modified chitosan and graphene oxide modified with a silane coupling agent into an acetic acid aqueous solution, heating and stirring, to obtain a premix of chitosan and graphene oxide; (4) Preparation of graphene oxide / chitosan / acrylamide composite hydrogel: adding acrylamide, an initiator, a crosslinking agent, and an acetic acid aqueous solution to the above premix to react and obtain a graphene oxide / chitosan / acrylamide composite hydrogel; In the step (4), the mass ratio of the premix, acrylamide, initiator, crosslinking agent and acetic acid aqueous solution is 1-10:10-30:0.01-0.1:0.1-1:10-100.
2. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: In the step (1), the mass ratio of graphene oxide to silane coupling agent is 1:1-10.
3. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: The reaction temperature in step (1) is 60-80°C, and the reaction time is 5-24h.
4. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: In the step (2), the mass ratio of chitosan, acrylic acid, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and water is 1-5:1-5:1-5:100-300.
5. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: The reaction temperature in step (2) is 20-40° C., and the reaction time is 1-5 h.
6. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: In the step (3), the mass ratio of the modified chitosan, the graphene oxide modified by the silane coupling agent, and the acetic acid aqueous solution is 1-5:0.005-0.1:1-10.
7. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: The mixing temperature in step (3) is 40-80° C., and the mixing time is 1-5 h.
8. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: The reaction temperature in step (4) is 40-60° C., and the reaction time is 12-14 h.
9. The method for preparing the graphene oxide / chitosan / acrylamide composite hydrogel according to claim 1, characterized in that: In step (4), the initiator is one or more of ammonium persulfate, potassium persulfate, and sodium persulfate; and the cross-linking agent is N,N-methylenebisacrylamide.
10. A graphene oxide / chitosan / acrylamide composite hydrogel prepared by the preparation method according to any one of claims 1 to 9.