Preparation method of sub-micron carbon cluster super-strong super-tough conductive hydrogel for slowing down crack propagation

Abstract

The application discloses a preparation method of super-strong and super-tough conductive hydrogel with sub-micron carbon clusters for slowing down crack propagation, and belongs to the technical field of hydrogel materials. The preparation method of the super-strong and super-tough conductive hydrogel comprises the following steps: mixing sodium carboxymethyl cellulose, dopamine and a solvent and then performing heat treatment to obtain a sub-micron carbon cluster solution; and mixing the sub-micron carbon cluster solution, an acrylamide monomer and an initiator and then performing a polymerization reaction to obtain the super-strong and super-tough conductive hydrogel. In order to improve the mechanical properties of the hydrogel, a new type of nanocluster is designed to serve as a nanofiller, and a high-performance crystalline hydrogel is prepared by using the pinning effect of the sub-micron carbon clusters on cracks. In the stretching process, the sub-micron carbon clusters can effectively slow down crack propagation, relieve stress concentration at crack tips and eliminate notch sensitivity, so that the mechanical strength of the hydrogel is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrogel materials technology, and more specifically relates to a method for preparing an ultra-strong and ultra-tough conductive hydrogel with submicron carbon clusters that slows down crack propagation. Background Technology

[0002] Hydrogels, due to their excellent flexibility and biocompatibility, have shown great potential in fields such as human-computer interfaces, flexible electronics, and soft robotics, which require materials with excellent mechanical properties and toughness. However, traditional hydrogels typically exhibit brittle or soft characteristics and lack effective energy dissipation mechanisms, resulting in low mechanical properties and toughness, limiting their application in load-bearing materials. To improve the toughness of hydrogels, researchers have designed specific mechanisms at the microscopic or macroscopic level. Common methods include constructing special structures, such as oriented nanofiber structures and nanocrystalline domains. These structures require significantly higher energy for failure than conventional hydrogels. Crystalline hydrogels, as modified hydrogels, significantly enhance their mechanical properties and toughness by introducing crystals. Crystals act as highly crosslinking agents, strengthening the structure of the hydrogel and providing additional support. During stretching, crystals strengthen the polymer chains and slow crack propagation through pinning effects, thereby achieving a toughening effect. Furthermore, the introduction of crystalline domains can also adjust the network structure of the hydrogel, affecting its hydration. In some cases, crystallization controls the expansion rate and extent of hydrogels by restricting water molecules from entering the crystalline regions, thus imparting morphological stability and preventing excessive expansion or water loss during long-term use. Researchers have prepared high-strength crystalline hydrogels through methods such as directional freezing, salting out, and solvent exchange. However, these methods increase crystallinity through polymer chain aggregation and rapid network contraction, leading to a decrease in the water content of the hydrogel. Furthermore, these methods often employ complex production processes, and many are only applicable to specific hydrogel systems. Designing single-network hydrogels that combine both mechanical properties and toughness remains a significant challenge.

[0003] Introducing interfacial effects between nanoparticles and polymers can effectively improve the mechanical properties and toughness of hydrogels. The abundant functional groups on the surface of nanoparticles interact with polymer chains, and non-covalent cross-linking enhances the mechanical strength of the hydrogel. However, most nanoparticles are incompatible with hydrogel precursor solutions, resulting in uneven distribution and failing to effectively enhance the hydrogel's performance. Furthermore, the high cost and complex synthesis process of nanoparticles limit the development of nanocomposite hydrogels. Therefore, developing an ultra-strong, ultra-tough, and conductive hydrogel is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing an ultra-strong and ultra-tough conductive hydrogel with submicron carbon clusters that slows down crack propagation, so as to solve the problems existing in the prior art and realize the preparation of ultra-strong and ultra-tough conductive hydrogel.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of this invention is to provide a method for preparing an ultra-strong and ultra-tough conductive hydrogel with submicron carbon clusters that slows down crack propagation, comprising the following steps:

[0007] A submicron carbon cluster solution was obtained by mixing sodium carboxymethyl cellulose, dopamine, and a solvent and then heat-treating the mixture.

[0008] The submicron carbon cluster solution, acrylamide monomer, and initiator are mixed and then subjected to a polymerization reaction to obtain the ultra-strong and ultra-tough conductive hydrogel.

[0009] To improve the mechanical properties of hydrogels, this invention designs a novel nanocluster as a nanofiller. High-performance crystalline hydrogels are prepared by utilizing the pinning effect of submicron carbon clusters on cracks. During the stretching process, the submicron carbon clusters can effectively slow down crack propagation, alleviate stress concentration at the crack tip, and eliminate notch sensitivity by pinning cracks and entangled polymer chains, thereby significantly improving the mechanical strength of the hydrogel.

[0010] Submicron carbon clusters, as novel carbon nanomaterials, possess excellent optical properties, non-toxicity, biocompatibility, and solubility. Furthermore, submicron carbon clusters exhibit a spatial structure different from carbon dots, producing effects similar to crystallization. More importantly, submicron carbon clusters are simple to prepare and possess spline properties. 2 Crystal nuclei endow materials with excellent electrical conductivity and interfacial interactions (such as π-π stacking, CH-π, etc.), thereby improving the compatibility of nanoparticles (submicron carbon clusters) with hydrogel precursor solutions, promoting the uniform distribution of nanoparticles, and effectively enhancing the performance of hydrogels.

[0011] In addition, the heat-treated carbonized sodium carboxymethyl cellulose and dopamine can well retain the active functional groups of the carbonized precursors, ensuring that the prepared submicron carbon clusters have good dispersibility. Furthermore, the use of these materials to prepare hydrogels introduces a large number of physical cross-linking reaction sites into the hydrogels, giving them ultra-high tensile strength and toughness.

[0012] Preferably, the solvent includes water.

[0013] Preferably, the ratio of sodium carboxymethyl cellulose, dopamine, and solvent is 0.5g:0.5g:100mL.

[0014] Preferably, the heat treatment temperature is 160°C and the heat treatment time is 1 hour.

[0015] This invention achieves the effect of slowing down crack propagation by controlling the ratio of raw materials and the parameters of heat treatment during the preparation of submicron carbon clusters. However, when the amount of sodium carboxymethyl cellulose is too high, it will result in too many carbon clusters, which will reduce the fracture energy. When the amount is too low, it will result in dopamine as the main component, which will also fail to slow down crack propagation.

[0016] Preferably, the acrylamide monomer comprises acrylamide and N,N-methylenebisacrylamide, wherein the mass ratio of acrylamide to N,N-methylenebisacrylamide is 2.5:0.004.

[0017] Preferably, the initiator comprises 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone.

[0018] Preferably, the mass ratio of the submicron carbon cluster solution, acrylamide monomer, and initiator is 5.625–9.375:2.5:0.05.

[0019] Preferably, the polymerization reaction is carried out under the following conditions: ultraviolet light conditions with a light intensity of 70 mw / m². 3 The temperature was 25±5℃ and the time was 2 minutes.

[0020] This invention can adjust the mechanical properties of hydrogels by controlling the ratio of raw materials used in the preparation process. Specifically, when the amount of submicron carbon clusters is high, the fracture stress and elongation of the hydrogel will decrease significantly, while when the amount is low, the submicron carbon clusters will only act as nanofillers, making the hydrogel brittle.

[0021] The second technical solution of the present invention provides an ultra-strong and ultra-tough conductive hydrogel prepared by the above preparation method.

[0022] The third technical solution of this invention provides the application of the above-mentioned ultra-strong and ultra-tough conductive hydrogel in the fields of human-computer interaction interfaces, flexible electronics and soft robots.

[0023] The present invention discloses the following technical effects:

[0024] 1. The submicron carbon clusters of the present invention, which can slow down crack propagation and prepare ultra-strong and ultra-tough conductive hydrogels, are prepared by sodium carboxymethyl cellulose and dopamine. During the stretching process, the submicron carbon clusters can effectively slow down crack propagation by pinning cracks and entangled polymer chains, thereby constructing a hydrogel with ultra-strong mechanical properties.

[0025] 2. The submicron carbon clusters prepared by this invention not only possess sp 2Crystal nuclei can impart excellent interfacial interactions to materials (such as π-π stacking, CH-π, etc.), and the heat-treated carbonized sodium carboxymethyl cellulose and dopamine can retain the functional groups of the carbonized precursors, ensuring that the prepared submicron carbon clusters have good dispersibility. Furthermore, using them to prepare hydrogels introduces a large number of physical cross-linking reaction sites to the hydrogels, giving them ultra-high tensile strength and toughness.

[0026] 3. The submicron carbon clusters obtained in this invention have a flower-like cluster structure, which can achieve the purpose of entanglement with polymer long chains and slowing down crack propagation (e.g., Figure 6 and Figure 7 (As shown). Attached Figure Description

[0027] Figure 1 The stress-strain curves and magnified views of the hydrogels prepared in Example 1 and Comparative Examples 1-6 are shown.

[0028] Figure 2 Stress-strain curves of the hydrogels prepared in Example 1 and Comparative Examples 9-10;

[0029] Figure 3 The stress-strain curves of the hydrogels prepared in Examples 1 to 3 are shown, where 1% represents Example 1, 0.75% represents Example 2, and 1.25% represents Example 3.

[0030] Figure 4 The stress-strain curves of the notched hydrogels prepared in Examples 1-3 and Comparative Examples 1, 4, 5, and 6 are shown.

[0031] Figure 5 The fracture energy is the value of the hydrogels prepared in Examples 1-3 and Comparative Examples 1, 4, 5, and 6.

[0032] Figure 6 This is a TEM image of the submicron carbon cluster solution obtained in Example 1;

[0033] Figure 7 A schematic diagram illustrating the preparation process of the ultra-strong and ultra-tough conductive hydrogel that slows down crack propagation using submicron carbon clusters. Detailed Implementation

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0036] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0037] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0038] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0039] Unless otherwise specified, the room temperature involved in this invention is 25±5℃.

[0040] Unless otherwise specified, all raw materials used in the embodiments and comparative examples of this invention are commercially available products.

[0041] Example 1

[0042] The specific steps for preparing an ultra-strong and ultra-tough conductive hydrogel with submicron carbon clusters that slows crack propagation are as follows:

[0043] S1. Add 0.5g sodium carboxymethyl cellulose and 0.5g dopamine to 100mL of deionized water, place in a pressure-resistant reaction flask and heat to 160℃ for 1h. Allow the reaction vessel to cool naturally to room temperature to obtain a submicron carbon cluster solution (CCs).

[0044] S2. After uniformly mixing CCs (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g), and N,N-methylenebisacrylamide (4mg), the mixture was irradiated with a UV lamp at 25℃ for 2min to obtain a super-strong and super-tough conductive hydrogel PAM-CCs (CCs-1%, m) with submicron carbon clusters that slow down crack propagation. CMC :m DA =1:1).

[0045] Example 2

[0046] The specific steps for preparing polyacrylamide-0.75% carbon nanoclusters hydrogel are as follows:

[0047] S1. Add 0.375g sodium carboxymethyl cellulose and 0.375g dopamine to 100mL of deionized water, place in a pressure-resistant reaction flask and heat to 160℃ for 1h. Allow the reaction vessel to cool naturally to room temperature to obtain carbon nanoclusters solution (CCs).

[0048] S2. After mixing CCs (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g) and N,N-methylenebisacrylamide (4mg) evenly, the mixture was irradiated with a UV lamp at 25°C for 2 min to obtain a super-strong and super-tough conductive hydrogel (CCs-0.75%) with carbon nanoclusters that slows down crack propagation.

[0049] Example 3

[0050] The specific steps for preparing polyacrylamide-1.25% carbon nanoclusters hydrogel are as follows:

[0051] S1. Add 0.625g sodium carboxymethyl cellulose and 0.625g dopamine to 100mL of deionized water, place in a pressure-resistant reaction flask and heat to 160℃ for 1h. Let the reaction vessel cool naturally to room temperature to obtain carbon nanoclusters solution (CCs).

[0052] S2. After mixing CCs (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g) and N,N-methylenebisacrylamide (4mg) evenly, the mixture was irradiated with a UV lamp at 25°C for 2 min to obtain a super-strong and super-tough conductive hydrogel (CCs-1.25%) with carbon nanoclusters that slows down crack propagation.

[0053] Comparative Example 1

[0054] The specific steps for preparing polyacrylamide hydrogels are as follows:

[0055] After mixing deionized water (7.5 g), acrylamide (2.5 g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05 g) and N,N-methylenebisacrylamide (4 mg) evenly, the mixture was irradiated with a UV lamp at 25 °C for 2 min to obtain polyacrylamide hydrogel (PAM).

[0056] Comparative Example 2

[0057] The specific steps for preparing polyacrylamide-dopamine hydrogel are as follows:

[0058] Deionized water (7.5 g), acrylamide (2.5 g), dopamine (0.075 g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05 g) and N,N-methylenebisacrylamide (4 mg) were mixed evenly and then irradiated with a UV lamp at 25 °C for 2 min to obtain polyacrylamide-dopamine (PAM-DA).

[0059] Comparative Example 3

[0060] The specific steps for preparing polyacrylamide-sodium carboxymethyl cellulose hydrogel are as follows:

[0061] Deionized water (7.5 g), acrylamide (2.5 g), sodium carboxymethyl cellulose (0.075 g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05 g) and N,N-methylenebisacrylamide (4 mg) were mixed evenly and then irradiated with a UV lamp at 25 °C for 2 min to obtain polyacrylamide-carboxymethyl cellulose sodium (PAM-CMC).

[0062] Comparative Example 4

[0063] The specific steps for preparing polyacrylamide-sodium carboxymethyl cellulose-dopamine hydrogel are as follows:

[0064] Deionized water (7.5 g), acrylamide (2.5 g), sodium carboxymethyl cellulose (0.0375 g), dopamine (0.0375 g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05 g), and N,N-methylenebisacrylamide (4 mg) were mixed evenly and then irradiated with a UV lamp at 25 °C for 2 min to obtain polyacrylamide-carboxymethyl cellulose sodium (PAM-CMC-DA).

[0065] Comparative Example 5

[0066] The specific steps for preparing polyacrylamide-dopamine carbon dot hydrogels are as follows:

[0067] S1. Add 1g of dopamine to 100mL of deionized water, place it in a pressure-resistant reaction flask and heat it to 160℃ for 1h. Let the reaction container cool naturally to room temperature to obtain a dopamine carbon dot solution.

[0068] S2. After mixing dopamine carbon dot solution (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g) and N,N-methylenebisacrylamide (4mg) evenly, the mixture was irradiated with a UV lamp at 25°C for 2 min to form polyacrylamide-dopamine carbon dot hydrogel (PAM-CDA).

[0069] Comparative Example 6

[0070] The specific steps for preparing polyacrylamide-sodium carboxymethyl cellulose carbon dot hydrogel are as follows:

[0071] S1. Add 1g of sodium carboxymethyl cellulose to 100mL of deionized water, place it in a pressure-resistant reaction flask and heat it to 160℃ for 1h. Let the reaction container cool naturally to room temperature to obtain sodium carboxymethyl cellulose carbon dot solution.

[0072] S2. After mixing sodium carboxymethyl cellulose carbon dot solution (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g) and N,N-methylenebisacrylamide (4mg) evenly, the mixture was irradiated with a UV lamp at 25°C for 2 min to obtain polyacrylamide-sodium carboxymethyl cellulose carbon dot hydrogel (PAM-CCMC).

[0073] Comparative Example 7

[0074] The preparation steps of polyacrylamide-carbon nanoclusters (sodium carboxymethyl cellulose and dopamine in a mass ratio of 2:1) hydrogel are as follows:

[0075] S1. Add 0.67g sodium carboxymethyl cellulose and 0.33g dopamine to 100mL of deionized water, place in a pressure-resistant reaction flask and heat to 160℃ for 1h. Let the reaction vessel cool naturally to room temperature to obtain a carbon nanocluster solution.

[0076] S2. After uniformly mixing CCs (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g), and N,N-methylenebisacrylamide (4mg), a super-strong and super-tough conductive hydrogel with carbon nanoclusters that slows crack propagation was obtained after irradiation with a UV lamp at 25℃ for 2min. CMC :m DA =2:1).

[0077] Comparative Example 8

[0078] The preparation steps of polyacrylamide-carbon nanoclusters (sodium carboxymethyl cellulose and dopamine in a mass ratio of 1:2) hydrogel are as follows:

[0079] S1. Add 0.33g sodium carboxymethyl cellulose and 0.67g dopamine to 100mL of deionized water, place in a pressure-resistant reaction flask and heat to 160℃ for 1h. Allow the reaction vessel to cool naturally to room temperature to obtain a carbon nanocluster solution.

[0080] S2. After uniformly mixing CCs (7.5g), acrylamide (2.5g), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (0.05g), and N,N-methylenebisacrylamide (4mg), a super-strong and super-tough conductive hydrogel with carbon nanoclusters that slows crack propagation was obtained after irradiation with a UV lamp at 25℃ for 2min. CMC :m DA =1:2).

[0081] Effect verification:

[0082] The mechanical properties, toughness, and fracture energy of the hydrogels prepared in Examples 1-3 and Comparative Examples 1-8 were tested as follows:

[0083] 1. The hydrogels prepared in Examples 1-3 and Comparative Examples 1-8 were cut into rectangular specimens (4cm×2mm×1mm) and subjected to tensile property tests at room temperature.

[0084] Uniaxial tensile testing was performed using an electronic universal testing machine (Shenzhen Sun Technology Co., Ltd., China), with an elongation speed of 80 mm / min.

[0085] Toughness is the area under the stress-strain curve, calculated using the following formula:

[0086] ΔU=∫σdε;

[0087] In the formula, σ and ε are the stress and strain of the hydrogel, respectively.

[0088] The results are shown in Table 1 and Figures 1-3 As shown.

[0089] 2. The hydrogels prepared in Examples 1, 2, 3 and Comparative Examples 1, 4, 5, 6 were cut into rectangular samples (4cm × 10mm × 1mm) and subjected to fracture energy testing at room temperature.

[0090] The fracture energy is calculated by cutting a 2mm wide notch into a 10mm wide hydrogel specimen, then calculating the critical strain (εc) for rapid crack propagation from the maximum stress on the stress-strain curve of the notched specimen. Subsequently, for the stress-strain curve of the unnotched specimen, the fracture energy value (Γ) is obtained by multiplying the integral area of ​​the notched specimen from the initial loading strain to the critical strain (εc) by the initial distance (H) between the two clamps. The calculation formula is as follows:

[0091]

[0092] In the formula, σ and εc are the stress and critical strain of the hydrogel, respectively.

[0093] The results are shown in Table 1 and Figures 4-5 As shown.

[0094] Table 1. Hydrogel properties obtained in Example 1 and Comparative Examples 1-10

[0095]

[0096]

[0097] As can be seen from the data in Table 1, the hydrogel prepared in Example 1 has the highest tensile strength and toughness, reaching 2.33137 MPa and 14.9359 MJ / m, respectively. 3 Furthermore, the data from Comparative Examples 1 to 6 show that the addition of heat-treated carbonized dopamine and sodium carboxymethyl cellulose to the hydrogel can improve the mechanical properties of the resulting hydrogel to some extent, but the improvement is relatively small.

[0098] Figure 1 The images show the stress-strain curves and magnified views of the hydrogels prepared in Examples 1 and Comparative Examples 1-6. Figure 1 As shown in Table 1, the mechanical properties of hydrogels prepared based on dopamine carbon dots and sodium carboxymethyl cellulose carbon dots heat-treated at 160℃ increased from 0.17610 MPa and 0.07024 MPa to 0.26079 MPa and 0.36971 MPa, respectively. Simultaneously, the deformation also increased. This is because the heat-treated carbon dots possess optimized surface properties and graphitization, resulting in a stronger bond between them and the hydrogel, thus improving mechanical properties. However, the increased strength is still unsatisfactory and does not reach the ideal level. In contrast, the use of submicron carbon clusters prepared by co-heat-treating dopamine and sodium carboxymethyl cellulose in hydrogels significantly improves the fracture strength and toughness of the hydrogels. This is because the submicron carbon clusters have a three-dimensional structure that intertwines with the long polymer chains, thereby greatly enhancing the mechanical properties of the hydrogels.

[0099] Figure 2The stress-strain curves are shown for the hydrogels prepared in Example 1 and Comparative Examples 7-8. Figure 2 As shown in Table 1, the tensile strength and toughness of hydrogels prepared from submicron carbon clusters obtained by heat treatment at mass ratios of sodium carboxymethyl cellulose and dopamine of 2:1, 1:1, and 1:2 are 0.83859 MPa, 2.33137 MPa, 0.51651 MPa, and 5.22174 MJ / m, respectively. 3 14.9359 MJ / m 3 2.70279 MJ / m 3 This is because in submicron carbon clusters, the long chains of sodium carboxymethyl cellulose (CMC) play a dominant role, similar to the trunk of a tree, serving as the supporting structure, while dopamine (DA) is similar to the branches, serving as lateral branches. When there is too much dopamine (DA), the lateral structures (branches) become too abundant, causing the trunk of the submicron carbon cluster to be unable to withstand excessive stress and thus failing to effectively mitigate crack propagation. Conversely, when there is too much sodium carboxymethyl cellulose (CMC), the role of dopamine (DA) is negligible, the lateral structures are fewer, and it is still unable to effectively slow down crack propagation.

[0100] Figure 3 The figures show the stress-strain curves of the hydrogels prepared in Examples 1-3, where 1% represents Example 1, 0.75% represents Example 2, and 1.25% represents Example 3. Figure 3 As shown in Table 1, the tensile strength and toughness of the hydrogels prepared based on submicron carbon clusters with mass concentrations of 0.75%, 1%, and 1.25% are 0.72117 MPa, 2.33137 MPa, 0.94364 MPa, and 5.63144 MJ / m, respectively. 3 14.9359 MJ / m 3 6.15552 MJ / m 3 It can be seen that the hydrogel prepared with a submicron carbon cluster mass concentration of 1% exhibits the highest mechanical properties and toughness. This is due to the nano-interface effect brought about by the nanoscale size of the submicron carbon clusters (CCs), as well as the pinning effect of the submicron carbon clusters on the hydrogel during stretching, which significantly increases the fracture stress and elongation of the hydrogel, thereby significantly improving its toughness. However, when the mass concentration of submicron carbon clusters (CCs) is further increased, the fracture stress and elongation of the hydrogel decrease. This is because excessive submicron carbon clusters (CCs) lead to poor interfacial compatibility between them and the hydrogel precursor, thus making the hydrogel brittle and reducing its toughness.

[0101] Figure 4 The stress-strain curves are for the notched hydrogels prepared in Examples 1, 2, 3 and Comparative Examples 1, 4, 5, 6. Figure 5The fracture energy is the value of the hydrogels prepared in Examples 1, 2, 3 and Comparative Examples 1, 4, 5, 6. Figure 4 , Figure 5 As shown in Table 1, the submicron carbon cluster with a mass concentration of 1% exhibits the highest fracture energy, reaching 126.42617 kJ / m. 2 This is because submicron carbon clusters can adapt to large deformations and fractures, effectively dissipating energy; and they are insensitive to crack propagation, still achieving a deformation of 1108%. This is due to the entanglement between the submicron carbon clusters and the hydrogel precursor chains, as well as the effective energy dissipation of the submicron carbon clusters for the stress at the crack tip, resulting in a fracture energy of 126.42617 kJ / m. 2 Furthermore, even low-concentration submicron carbon clusters exhibit a fracture energy of 40.46864 kJ / m². 2 This is all thanks to the effective slowing of crack propagation by submicron carbon clusters.

[0102] In summary, this invention designs a novel nanocluster as a nanofiller, utilizing the pinning effect of submicron carbon clusters on cracks to prepare a high-performance crystalline hydrogel. During stretching, the submicron carbon clusters effectively slow crack propagation, alleviate stress concentration at crack tips, and eliminate notch sensitivity by pinning cracks and entangled polymer chains, thereby significantly improving the mechanical strength of the hydrogel. Furthermore, the submicron carbon clusters are simple to prepare and possess SP... 2 Crystal nuclei endow materials with excellent electrical conductivity and interfacial interactions (such as π-π stacking, CH-π, etc.), thereby improving the compatibility of nanoparticles (submicron carbon clusters) with hydrogel precursor solutions, promoting the uniform distribution of nanoparticles, and effectively enhancing the performance of hydrogels.

[0103] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0104] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a sub-micron carbon cluster reinforced super tough and super ductile conductive hydrogel for mitigating crack propagation, characterized in that, The preparation method comprises the following steps: mixing sodium carboxymethyl cellulose, dopamine and a solvent, and then performing heat treatment to obtain a sub-micron carbon cluster solution; mixing the sub-micron carbon cluster solution, an acrylamide monomer and an initiator, and then performing a polymerization reaction to obtain the super-strong and super-tough conductive hydrogel; a mass ratio of the sodium carboxymethyl cellulose, the dopamine and the solvent is 0.5g:0.5g:100mL; the heat treatment is performed at a temperature of 160℃ for 1h; the acrylamide monomer comprises acrylamide and N,N-methylene bisacrylamide, and a mass ratio of the acrylamide and the N,N-methylene bisacrylamide is 2.5:0.004; a mass ratio of the sub-micron carbon cluster solution, the acrylamide monomer and the initiator is 5.625~9.375:2.5:0.

05.

2. The production method according to claim 1, characterized by, the solvent comprises water.

3. The preparation method according to claim 1, characterized in that, the initiator comprises 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone.

4. The method of claim 1, wherein, The conditions of the polymerization reaction: UV light condition, light intensity of 70 mw / m 3 , temperature of 25±5℃, time of 2 min.

5. The super-strong and super-tough conductive hydrogel prepared by the preparation method in any one of claims 1-4.

6. Application of the super-strong and super-tough conductive hydrogel in claim 5 in the fields of human-computer interaction interfaces, flexible electronics and soft robots.

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