A large-size MXene-based water-resistant and tack-stabilized adhesive and its preparation method

Abstract

This invention discloses a large-size MXene-based water-resistant and stable adhesive and its preparation method, belonging to the technical field of adhesive materials. The method includes: preparing a large-size MXene into an aqueous dispersion, injecting it into an aqueous polyethyleneimine solution to obtain an MXene@PEI composite dispersion A; preparing an aqueous polyacrylic acid solution B; mixing solutions A and B, and forming a gel through electrostatic interaction, hydrogen bonding, and molecular chain entanglement, thus obtaining the adhesive. The adhesive exhibits an lap shear strength ≥1.3 MPa on a dry glass surface, an lap shear strength ≥0.9 MPa on a water-wetted glass surface, and a strength retention rate ≥55% after immersion in deionized water for 7 days. This invention utilizes the multiple synergistic effects of large-size MXene with PEI and PAA to significantly improve the adhesive's cohesiveness, wet adhesion, and water aging resistance, and the preparation process is simple.

Description

Technical Field

[0001] This invention relates to the field of adhesive materials technology, and in particular to a large-size MXene-based water-resistant and tack-stabilized adhesive and its preparation method. Background Technology

[0002] Adhesives, as key materials for connecting materials in industry and daily life, directly determine the reliability and service life of the connected structure through their bonding performance. From traditional wood processing and building decoration to the booming flexible electronics assembly, biomedical packaging, and marine engineering equipment maintenance, the demand for adhesives is becoming increasingly diversified and sophisticated. Among them, adhesives that can maintain stable bonding effects in humid environments and even underwater, namely "water-resistant and stable adhesives," are becoming a hot research and development area in the industry.

[0003] However, existing adhesives face significant technical bottlenecks in humid and aqueous environments. When a water film exists on the substrate surface or the substrate is underwater, water molecules form a dense hydration layer at the substrate interface. This not only hinders the effective wetting and spreading of the adhesive but also occupies active binding sites between the adhesive and the substrate through hydrogen bonding, significantly weakening interfacial adhesion. Simultaneously, the diffusion of water molecules into the adhesive interior leads to polymer network swelling, decreased cohesion, and even degradation. Therefore, developing water-resistant, stable adhesives that combine high cohesion, strong interfacial adhesion, and excellent wet stability has become a critical technical problem urgently needing to be solved in this field.

[0004] To address the challenges of adhesion in humid environments, researchers have explored various technical approaches. Regarding polyelectrolyte composite systems, the use of polyelectrolytes with opposite charges to construct gel adhesives through electrostatic interactions has proven to be an effective strategy for achieving adhesion in wet conditions. This is because the gel can remove the interfacial hydration layer and enhance the intermolecular interactions between the gel and the substrate through electrostatic repulsion under wet conditions. For example, Chinese patent CN118846194A discloses a water-gelling medical adhesive powder, its preparation method, and its applications. This powder is composed of a crosslinked network system of poly(acrylic acid-succinimide) and polyethyleneimine (PEI). After absorbing water, the powder rapidly gels and exhibits good adhesion properties to biological tissues. Chinese patent CN116751545B discloses a waterproof adhesive and its preparation method. This adhesive layer with certain water resistance is obtained by combining hyperbranched polyethyleneimine-modified acrylate emulsion with oxidized polysaccharides and calcium silicate and calcium aluminate gels to form a multi-layered interwoven network. Furthermore, Ji Hua's laboratory developed a polyelectrolyte complex formed by the Coulombic interaction between chitosan (positively charged) and polyanions, which can remove the hydration layer at tissue interfaces and achieve strong underwater adhesion. However, although the aforementioned polyelectrolyte gel adhesives achieve basic wet bonding functions, their cohesive strength depends on the electrostatic cross-linking between polyelectrolyte molecular chains. The cross-linking density is limited, the network structure is relatively simple, and the mechanical strength and water penetration resistance of the adhesive itself are still insufficient. Under long-term water immersion conditions, the bonding strength decays rapidly, making it difficult to meet the requirements of harsh wet service environments.

[0005] In the field of two-dimensional nanomaterial reinforcement and modification, MXene, as an emerging transition metal carbon / nitride two-dimensional nanomaterial, has been widely used in the functionalization modification of composite materials due to its rich surface area of ​​active functional groups such as hydroxyl and oxygen groups, large specific surface area, and excellent electrical and thermal conductivity. Chinese patent CN119284906A discloses a large-sheet MXene material, its preparation method, and its applications. This material, with an average transverse dimension of over 4.2 μm, is obtained through mechanical stress shear exfoliation and shows promising application prospects in the field of electromagnetic shielding. In the adhesive field, existing technologies mainly introduce MXene as a conductive filler or mechanical reinforcing component into conventional adhesive systems. For example, Chinese patent CN121248367A discloses an MXene-based adhesive and a tungsten-based delay agent and its method, which mixes a chloroacetic acid resin solution, a polyvinylidene fluoride-hexafluoropropylene solution, and an MXene suspension for use in a tungsten-based delay agent. Other studies have combined MXene with natural polymers such as chitosan and sodium alginate, attempting to use it in lithium-ion battery adhesives or biomedical materials. However, existing technologies still have significant shortcomings in combining MXene with polyelectrolyte gel adhesives: MXene exhibits poor dispersion stability in gel systems and is prone to agglomeration, forming defects that undermine the integrity of the gel network; the abundant active functional groups on the surface of MXene fail to form an effective synergistic reinforcing network with the gel matrix, resulting in limited improvement in the mechanical properties of the adhesive; more critically, the inherent oxidative properties of MXene (rapid oxidation to TiO2 in air or aqueous solution) severely limit its long-term stable application in adhesives.

[0006] In summary, existing technologies for water-resistant and tack-stabilized adhesives can be categorized into three types: polyelectrolyte composite systems achieve wet adhesion but lack sufficient cohesion; two-dimensional material reinforcement and modification improve mechanical properties but limit dispersibility and oxidative stability; and simple combinations of both fail to produce synergistic reinforcement due to a lack of reasonable interface design. Therefore, how to simultaneously improve the wet adhesion, cohesion, and water aging resistance of polyelectrolyte adhesives, while addressing the dispersion and oxidation issues of MXene within them, is a pressing technical challenge in this field. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention adopts the following technical solution:

[0008] A method for preparing a large-size MXene-based water-resistant and tack-stabilized adhesive includes the following steps:

[0009] Step 1: Prepare a large-size MXene aqueous dispersion, prepare a polyethyleneimine aqueous solution, and inject the MXene aqueous dispersion into the polyethyleneimine aqueous solution to obtain an MXene@PEI composite dispersion, denoted as solution A; wherein, the lateral dimension of the large-size MXene is 10~25μm;

[0010] Step 2: Prepare an aqueous solution of polyacrylic acid, denoted as solution B;

[0011] Step 3: Mix liquid A and liquid B, and form a gel through electrostatic interaction, hydrogen bonding and molecular chain entanglement to obtain a water-resistant and tack-stabilized adhesive.

[0012] Preferably, the molecular weight of the polyethyleneimine is 5,000 to 20,000, and the molecular weight of the polyacrylic acid is 100,000 to 200,000.

[0013] Preferably, in step one, the concentration of the MXene aqueous dispersion is 0.5~2 mg / mL, the concentration of the polyethyleneimine aqueous solution is 1~10 mg / mL, and the volume ratio of the two is 1:10~1:200.

[0014] Preferably, in step one, the aqueous dispersion of MXene is injected into the aqueous solution of polyethyleneimine under ultrasonic conditions, with an ultrasonic power of 20~100W and a time of 5~30min; and the aqueous dispersion of MXene is purged with inert gas before injection to remove dissolved oxygen.

[0015] Preferably, in step three, the volume ratio of liquid A to liquid B is 5:1 to 5:5.

[0016] More preferably, the volume ratio of liquid A to liquid B is 5:2 to 5:5.

[0017] Preferably, in step three, the mixing involves adding liquid B dropwise to liquid A under stirring conditions, with a stirring speed of 200-600 rpm and a dropping time of 0.5-2 min. After the dropping is completed, stirring continues for 5-20 min, followed by standing for 0.5-2 h.

[0018] The present invention also provides a large-size MXene-based water-resistant and stable adhesive, which is prepared by the above-mentioned method for preparing large-size MXene-based water-resistant and stable adhesive.

[0019] Preferably, the large-size MXene-based water-resistant and tack-stabilized adhesive has an overlap shear strength ≥1.3MPa on a dry glass surface and an overlap shear strength ≥0.9MPa on a water-wetted glass surface.

[0020] Preferably, the large-size MXene-based water-resistant and tack-stabilized adhesive retains ≥55% of its strength after being soaked in deionized water for 7 days.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. By employing large-sized MXene with a lateral dimension of 10~25μm, and pre-compositing it with polyethyleneimine to form an MXene@PEI structure, followed by mixing with polyacrylic acid, the two-dimensional sheet structure of the large-sized MXene serves as the physical crosslinking center. This, combined with electrostatic interactions, hydrogen bonds, and molecular chain entanglement, constructs a high-density, multi-layered three-dimensional network. This structure significantly enhances the intrinsic cohesive force of the adhesive, solving the problem of low mechanical strength caused by insufficient crosslinking density in existing polyelectrolyte gel adhesives.

[0023] 2. The polyelectrolyte composite system formed by positively charged polyethyleneimine and negatively charged polyacrylic acid in this invention can effectively eliminate the interfacial hydration layer; at the same time, the abundant functional groups on the large-size MXene surface further enhance the intermolecular forces with the substrate, solving the problem of adhesion failure of existing adhesives on water-wetted substrate surfaces due to the obstruction of the hydration layer.

[0024] 3. This invention effectively inhibits the penetration and diffusion of water molecules by utilizing the physical barrier effect of large-size MXene and the low swelling characteristics of the multi-crosslinked network, thus solving the defect of rapid attenuation of bonding strength of existing adhesives under long-term water immersion conditions.

[0025] 4. By pre-coating MXene sheets with polyethyleneimine molecular chains (molecular weight 5000~20000), the oxidation of MXene is significantly inhibited through steric hindrance and local microenvironment isolation, the storage stability and process reliability of the adhesive are improved, and the problem of easy oxidation and deactivation of traditional MXene composite materials is overcome.

[0026] 5. This invention does not require complex equipment or harsh reaction conditions. High-performance water-resistant and stable adhesives can be prepared simply by solution mixing, ultrasonic dispersion and static gelation. It has a wide operating window and good reproducibility, which is beneficial for large-scale production and practical engineering applications. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to embodiments and comparative examples, but the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise stated, the raw materials, reagents, etc. used in the following embodiments are all commercially available products.

[0028] The raw materials and reagents are as follows:

[0029] MAX phase ceramics: Ti3AlC2 powder (purity ≥98%, particle size 200 mesh).

[0030] Lithium fluoride (LiF): Analytical grade, purity ≥99%.

[0031] Hydrochloric acid (HCl): analytical grade, concentration 37% (approximately 12 mol / L), dilute to the required concentration before use.

[0032] Polyethyleneimine (PEI): Molecular weight 5000, 10000, 20000.

[0033] Polyacrylic acid (PAA): molecular weight 100,000, 150,000, 200,000.

[0034] Deionized water: prepared in the laboratory, resistivity ≥18.2MΩ·cm.

[0035] Large-size MXene (Ti3C2T) X All were prepared according to the following method:

[0036] A1: Dissolve 1g of lithium fluoride (LiF) in 20mL of 9mol / L hydrochloric acid solution (HCl) and stir for 10min until completely dissolved;

[0037] A2: Slowly add 1g of Ti3AlC2 powder while stirring, and stir and react in a 35℃ water bath for 24h;

[0038] A3: Transfer the reaction product to a centrifuge tube, centrifuge at 3500 rpm for 5 min, discard the supernatant, wash the precipitate with deionized water and centrifuge several times until the pH of the supernatant is ≈6, to obtain a multilayer MXene precipitate;

[0039] A4: Disperse the precipitate in deionized water and perform ultrasonic stripping of the probe under ice-water bath conditions (power 200W, pulse mode: 10s ultrasound, 5s pause, total ultrasound time 1h), with nitrogen protection throughout the process.

[0040] A5: Centrifuge the ultrasonicated dispersion at 3500 rpm for 30 min and collect the supernatant;

[0041] A6: Centrifuge the supernatant at different speeds, collect the precipitate, and obtain MXene of different sizes:

[0042] Large-sized MXene (average transverse size 20μm): Centrifuge at 8000rpm for 20min and collect the precipitate;

[0043] Large-sized MXene (average transverse size 10 μm): Centrifuge at 10,000 rpm for 20 min and collect the precipitate;

[0044] Large-sized MXene (average transverse size 25μm): Centrifuge at 6500rpm for 15min and collect the precipitate;

[0045] Small-sized MXene (for comparison, average lateral size 3.5μm): Centrifuge at 12000rpm for 30min and collect the precipitate.

[0046] The average lateral dimension of the MXene sheet was determined by statistically analyzing the lateral dimensions of at least 100 MXene sheets.

[0047] Example 1: The preparation method of the large-size MXene-based water-resistant and tack-stabilized adhesive in this example includes the following steps:

[0048] Step 1: Take the large-sized MXene (average transverse size 20 μm) prepared by the above method, disperse it in deionized water, and prepare an MXene aqueous dispersion with a concentration of 1.0 mg / mL. Purge with argon (Ar) for 20 min to remove dissolved oxygen, and maintain an inert atmosphere throughout the process.

[0049] Separately dissolve polyethyleneimine (PEI, molecular weight 10000) in deionized water to prepare a PEI aqueous solution with a concentration of 5 mg / mL, and use 100 mL.

[0050] Under ultrasonic conditions (ultrasonic power 50W), 3 mL of MXene aqueous dispersion was slowly injected into 100 mL of PEI aqueous solution (injection time approximately 1 min), and ultrasonication was continued for 10 min to obtain a homogeneous and stable MXene@PEI composite dispersion, denoted as solution A (total volume approximately 103 mL). This dispersion was dark green and showed no precipitate.

[0051] Step 2: Dissolve polyacrylic acid (PAA, molecular weight 150,000) in deionized water to prepare a PAA aqueous solution with a concentration of 5 mg / mL. Stir magnetically at room temperature until completely dissolved, and record this as solution B (colorless and transparent solution).

[0052] Step 3: At room temperature (25±2℃), take 10mL of solution A and place it in a 50mL beaker. Under magnetic stirring (400rpm), add solution B dropwise to solution A at a volume ratio of A:B=5:3 (i.e., 6mL) over 1min. During the dropwise addition, a large amount of flocculent matter will be observed to form, and the system will gradually thicken. After the dropwise addition is complete, continue stirring for 10min, and then let it stand for 1h to form a blocky gel, which is the large-size MXene-based water-resistant and stable adhesive.

[0053] The preparation methods for Examples 2-6 are basically the same as those for Example 1, with the only difference being the process parameters, as shown in Table 1. Unspecified parameters and operations remain consistent with those in Example 1.

[0054] Table 1. Key process parameters for Examples 2-6

[0055]

[0056] Comparative Example 1 (MXene-free): The only difference between this comparative example and Example 1 is step one: 3 mL of deionized water was used instead of the MXene aqueous dispersion to inject into the PEI aqueous solution, resulting in MXene-free solution A′. All other parameters were identical to those in Example 1, ultimately yielding the comparative adhesive.

[0057] Comparative Example 2 (small-sized MXene): The only difference between this comparative example and Example 1 is step one: the small-sized MXene (average lateral size 3.5 μm) prepared by the above method is used to prepare an aqueous dispersion. The other parameters are exactly the same as in Example 1, resulting in liquid A and finally the comparative adhesive.

[0058] Comparative Example 3 (MXene directly mixed with PAA), this comparative example includes the following steps:

[0059] Step 1: The large-sized MXene (average transverse size 20 μm) prepared by the above method is dispersed in deionized water to prepare an MXene aqueous dispersion with a concentration of 1.0 mg / mL (without adding PEI). The dispersion is purged with argon (Ar) for 20 min and denoted as solution A″.

[0060] Step 2: Same as Example 1.

[0061] Step 3: At room temperature, take 10 mL of solution A″ and place it in a 50 mL beaker. Under magnetic stirring (400 rpm), add solution B dropwise to solution A″ at a volume ratio of A″:B=1:1 (i.e., 10 mL) over 1 minute.

[0062] Results: Since both MXene and PAA are negatively charged, electrostatic repulsion hinders the formation of the gel network. The system cannot form a stable gel, and only black precipitate and supernatant are obtained. It has no practical adhesive properties and is not tested.

[0063] Comparative Example 4 (PEI molecular weight exceeding 5000-20000): This comparative example differs from Example 1 only in step one: the PEI molecular weight used is 1000. All other parameters are identical to Example 1, resulting in solution A and the final preparation of the comparative adhesive. Observation revealed that solution A exhibited a black precipitate within 24 hours, indicating poor stability. Freshly prepared solution A (before precipitation) was mixed with solution B, resulting in a loose gel texture.

[0064] The performance testing method is as follows:

[0065] Overlap shear strength test (dry, wet, and water aging resistance): Following ASTM D1002-10 standard, a glass slide (75mm × 25mm × 1mm, glass material) was used as the bonding substrate. Before bonding, the slide was ultrasonically cleaned with acetone, ethanol, and deionized water for 15 minutes sequentially, and then dried with nitrogen.

[0066] Dry test sample: Apply adhesive (approximately 0.1g) to one end of a glass slide (adhesive area approximately 1cm²). 2 Immediately cover with another glass slide, apply a 100g weight, and cure at room temperature for 24 hours.

[0067] Wet test specimens: Immerse the cleaned glass slide in deionized water for 10 seconds, remove it and gently absorb the visible flowing water on the surface with filter paper (retaining a uniform water film), then apply adhesive, overlap and cure as described above.

[0068] Dry / wet test: The lap shear strength is tested on a universal testing machine at a loading rate of 10 mm / min. At least 5 parallel samples are used in each group, and the average value ± standard deviation is taken.

[0069] Water resistance aging test: The sample prepared according to the "dry state test sample" method is completely immersed in deionized water, and the deionized water is changed every 24 hours. It is left to stand at room temperature for 7 days. After taking it out, the surface moisture is dried, and the strength is tested according to the above method. The strength retention rate is calculated as follows: Strength retention rate = (strength after aging / initial dry state strength) × 100%.

[0070] Antioxidant stability test: Freshly prepared solution A (or corresponding component) from the examples and comparative examples were placed in an open environment (25°C, 60% relative humidity) in the dark for 7 days, and the color change and precipitation were observed. Solution A in all examples remained dark green after 7 days, with no obvious precipitation. Then, the placed solution A was mixed with the corresponding solution B in the original ratio to prepare a gel. The wet adhesive strength was measured according to the "wet test" method described above, and compared with the wet strength of the gel prepared using fresh solution A. The strength retention rate was calculated as follows: Retention rate = (wet strength after aging / fresh wet strength) × 100%.

[0071] The test results of Examples 1-6 and Comparative Examples 1-4 (mean ± standard deviation of parallel samples n=5) are shown in Table 2 below.

[0072] Table 2. Test results of Examples 1-6 and Comparative Examples 1-4

[0073]

[0074] The results of the above embodiments and comparative examples show that:

[0075] 1. Compared with Comparative Example 1, the dry, wet, and aged strengths of all examples were significantly improved after the introduction of MXene. Compared with Comparative Example 2, the wet strength (0.95 MPa) and 7-day strength retention rate (59.1%) of Example 2 (10 μm) using large-size MXene were much higher than those of Comparative Example 2; when the size was further increased to 20 μm (as in Example 1), the wet strength increased to 1.42 MPa, and the retention rate reached 68.1%. This indicates that large-size MXene can form more effective physical crosslinking centers. When the size was further increased to 25 μm (as in Example 3), the performance was slightly lower than that of 20 μm due to a slight decrease in dispersibility, but it was still significantly better than the small-size comparative example.

[0076] 2. In Comparative Example 3, large-sized MXenes without PEI pre-composite were directly mixed with PAA. Because both MXenes and PAA are negatively charged, electrostatic repulsion prevented the formation of a stable gel. This indicates that pre-composite MXenes with PEI to form an MXene@PEI structure is a prerequisite step for utilizing MXene to enhance the polyelectrolyte gel network and achieve the technical effects of this application.

[0077] 3. Comparative Example 4 used PEI with a molecular weight of 1000. Due to insufficient chain length, it was difficult to effectively encapsulate MXene, resulting in poor stability of solution A and a loose gel texture with a dry strength of only 0.85 MPa and a wet strength of only 0.42 MPa. However, when the molecular weight of PEI was between 5000 and 20000, solution A was stable (no precipitation after 7 days), and the gel exhibited excellent mechanical properties. Therefore, the molecular weight of PEI needs to be controlled within the range of 5000 to 20000.

[0078] 4. Examples with an A:B volume ratio of 5:1 to 5:5 all formed gels and achieved performance superior to the comparative examples. Specifically, when the A:B ratio was 5:2 to 5:5, the wet strength was ≥1.12 MPa, the 7-day strength retention rate was ≥60%, and the dry strength was ≥1.55 MPa, significantly better than Example 2 with an A:B ratio of 5:1 (wet strength 0.95 MPa, strength retention rate 59.1%). Therefore, an A:B volume ratio of 5:2 to 5:5 is preferred.

[0079] In summary, this invention successfully constructs a high-performance, water-resistant, and stable adhesive with a multi-layered cross-linked network by using large-sized MXene with a lateral dimension of 10-25 μm, pre-compositing it with PEI with a molecular weight of 5000-20000 to form solution A, and then mixing it with an aqueous solution of PAA with a molecular weight of 100000-200000 (solution B) at a ratio of A:B = 5:1 to 5:5. Experimental data demonstrate that this adhesive exhibits excellent bonding strength and stability under dry, wet, and long-term water immersion conditions. Furthermore, the preparation process is simple, reproducible, and has significant industrial application value.

[0080] Structures, components, and connection methods not described in detail in this invention are all prior art known to those skilled in the art unless otherwise specified. It is obvious to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the invention. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description, and therefore all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this invention.

Claims

1. A method for preparing a large-size MXene-based water-resistant and tack-stabilized adhesive, characterized in that, Includes the following steps: Step 1: Prepare a large-size MXene aqueous dispersion, prepare a polyethyleneimine aqueous solution, and inject the MXene aqueous dispersion into the polyethyleneimine aqueous solution to obtain an MXene@PEI composite dispersion, denoted as solution A; wherein, the lateral dimension of the large-size MXene is 10~25μm; Step 2: Prepare an aqueous solution of polyacrylic acid, denoted as solution B; Step 3: Mix liquid A and liquid B, and form a gel through electrostatic interaction, hydrogen bonding and molecular chain entanglement to obtain a water-resistant and tack-stabilized adhesive.

2. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 1, characterized in that, The molecular weight of the polyethyleneimine is 5,000 to 20,000, and the molecular weight of the polyacrylic acid is 100,000 to 200,000.

3. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 1, characterized in that, In step one, the concentration of MXene aqueous dispersion is 0.5~2 mg / mL, the concentration of polyethyleneimine aqueous solution is 1~10 mg / mL, and the volume ratio of the two is 1:10~1:

200.

4. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 1, characterized in that, In step one, the aqueous dispersion of MXene is injected into the aqueous solution of polyethyleneimine under ultrasonic conditions, with an ultrasonic power of 20~100W and a time of 5~30min; and the aqueous dispersion of MXene is purged with inert gas before injection to remove dissolved oxygen.

5. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 1, characterized in that, In step three, the volume ratio of liquid A to liquid B is 5:1 to 5:

5.

6. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 5, characterized in that, The volume ratio of liquid A to liquid B is 5:2 to 5:

5.

7. The method for preparing the large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 1, characterized in that, In step three, the mixing involves adding liquid B dropwise to liquid A under stirring conditions. The stirring speed is 200-600 rpm, the dropping time is 0.5-2 min, and stirring continues for 5-20 min after the dropping is completed. Then, the mixture is allowed to stand for 0.5-2 h.

8. A large-size MXene-based water-resistant and tack-stabilized adhesive, characterized in that, It is prepared by the method for preparing large-size MXene-based water-resistant and tack-stabilized adhesives according to any one of claims 1 to 7.

9. The large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 8, characterized in that, Its lap shear strength on dry glass surfaces is ≥1.3MPa, and its lap shear strength on water-wetted glass surfaces is ≥0.9MPa.

10. The large-size MXene-based water-resistant and tack-stabilized adhesive according to claim 8, characterized in that, Its strength retention rate is ≥55% after soaking in deionized water for 7 days.

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