Wet adhesive as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of cultural relic repair, and particularly relates to a wet adhesion adhesive and a preparation method and application thereof.The adhesive comprises tannic acid, silk fibroin and fibrous protein.The preparation method comprises the steps that a silk fibroin solution is prepared, specifically, a solvent is added into fibroin sponge to be dissolved, the silk fibroin solution is obtained after complete dissolution, and the silk fibroin solution is sealed for use; preparing a tannic acid solution: adding a solvent into tannic acid to dissolve the tannic acid completely to obtain the tannic acid solution, and sealing the tannic acid solution for later use; preparing fibrin: uniformly mixing a fibrinogen solution with CaCl, freezing after solidification, and freeze-drying; fibrin is dissolved in a silk fibroin solution, the fibrin is stirred and dispersed, then tannic acid is added for a reaction, stirring is conducted till the fibrin and the tannic acid are cross-linked to form gel, and the gel is soaked in a tannic acid solution. The silk fibroin tannic acid adhesive is used for cultural relic repair, easy to operate, high in wet adhesion, resistant to aging and suitable for adhesion of cultural relics made of different materials.

Description

Technical Field

[0001] This invention belongs to the field of cultural relic restoration technology, specifically relating to a wet adhesive, its preparation method, and its application. Background Technology

[0002] Cultural relic restoration is a core aspect of cultural heritage protection, and its primary principle is to achieve the long-term preservation of the historical, artistic, and scientific value of cultural relics with minimal intervention. The choice of adhesive directly determines the stability and durability of the restoration effect. Currently, commonly used restoration adhesives mainly include natural glues (such as starch glue and animal glue), cellulose derivatives (such as carboxymethyl cellulose), and synthetic polymer materials (such as polyvinyl acetate and acrylic resin).

[0003] Currently, the domestic adhesive field for cultural relic restoration presents a coexistence of tradition and innovation. Mainstream adhesives such as epoxy resin, acrylic resin, and traditional animal glue (such as fish glue) are still widely used in the restoration of ceramic, stone, and wooden cultural relics due to their mature processes and stable performance. However, epoxy resin's cross-linked network is too rigid and lacks flexibility, making it difficult to adapt to the long-term micro-deformation of cultural relics. Furthermore, it is prone to stress cracking after aging, making removal difficult; its curing speed is significantly affected by temperature, with slow reaction at low temperatures. While cyanoacrylate cures rapidly, the curing process is significantly exothermic, potentially causing thermal stress damage to fragile cultural relics. The cured product also has high hardness and poor toughness, making stress concentration at the interface common. In addition, existing adhesives generally lack effective adhesion to wet surfaces; solvent-based products tend to "curl" on damp surfaces and cannot spread fully. Common pre-drying treatments are not only cumbersome but can also cause secondary damage to cultural relics due to excessive water loss, leading to cracking or salt crystallization. Linear polymers such as Paraloid B72 are prone to brittleness and low elongation at break (often <5%). They are susceptible to brittle cracking under environmental vibration or temperature and humidity changes, and long-term exposure can lead to oxidative embrittlement and yellowing.

[0004] Therefore, existing materials generally have the following limitations in practical applications: insufficient adhesion to wet surfaces, which makes the repaired area prone to failure in humid environments; excessive curing time, cumbersome operation, and may cause secondary damage to fragile cultural relics; poor aging resistance, which can easily lead to yellowing, embrittlement, and even accelerate the deterioration of the cultural relics themselves. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a wet adhesive, its preparation method, and its application, achieving the goals of simple operation, strong wet adhesion, anti-aging properties, and applicability to the adhesion of cultural relics made of different materials.

[0006] To address the aforementioned issues, some studies have attempted to improve the process. For example, Guo et al. developed a thermosetting acrylamide adhesive (THA) composed of an aqueous solution of ammonium persulfate (part A) and a precursor solution (part B) consisting of acrylamide, polyvinyl alcohol, and a crosslinking agent. This material forms an interpenetrating polymer network (IPN) through in-situ polymerization, but its application is mainly limited to ceramic artifacts, with no reports on other materials such as wood and grottoes. Shi et al. introduced calcium carbonate into acrylamide hydrogel to prepare a calcium-based biomimetic mineralized hydrogel (Ca-gel). This material exhibits controllable adhesion strength and good biocompatibility, providing a rapid bonding solution for ancient bone artifacts. However, it still cannot achieve wet adhesion and suffers from easy aging and yellowing.

[0007] The technical problem solved by this invention is achieved by the following technical solution:

[0008] The present invention aims to provide a wet adhesive comprising a phenolic hydroxyl compound, silk fibroin, and fibroin.

[0009] Furthermore, the compound containing phenolic hydroxyl groups is tannic acid, and the volume ratio of tannic acid to silk fibroin is 1:1.

[0010] Furthermore, fibrin accounts for 2-3 wt% of the adhesive.

[0011] Furthermore, the concentration of silk fibroin is 10-50 wt%, and the concentration of tannic acid is 10-50 wt%.

[0012] Furthermore, the concentration of silk fibroin was 20 wt%, the concentration of tannic acid was 30 wt%, and the proportion of fibroin in the adhesive was 2.4 wt%.

[0013] A method for preparing a wet adhesion adhesive, comprising:

[0014] Preparation of silk fibroin solution: Add solvent to silk fibroin sponge and dissolve. After complete dissolution, obtain silk fibroin solution and seal for later use.

[0015] Preparation of a solution containing phenolic hydroxyl groups: Dissolve the compound containing phenolic hydroxyl groups in a solvent until completely dissolved to obtain a solution containing phenolic hydroxyl groups, then seal and store for later use.

[0016] Preparation of fibrin: Mix fibrinogen solution with CaCl2 evenly, freeze after solidification, and freeze-dry.

[0017] Preparation of adhesive: Fiber protein is dissolved in silk fibroin solution, the fiber protein is stirred and dispersed, then a compound containing phenolic hydroxyl groups is added and reacted, and stirred until cross-linked into an adhesive, which is then soaked in tannic acid solution.

[0018] Furthermore, in preparing the silk fibroin solution, the solvent is water or buffer solution, and the dissolution process is carried out under stirring or heating conditions. The resulting silk fibroin solution is then stored in a sealed refrigerator at 1-7°C for 0-12 hours for later use.

[0019] Furthermore, the preparation method of silk fibroin sponge includes: using degummed silk fibroin and water at a mass ratio of 1:12-30, dissolving it with 9.8-20.8 mol / L lithium bromide, stirring in a water bath at 50-70℃ for 3-5 h, filtering, dialyzing in deionized water using a dialysis bag, freezing, and then freeze-drying in a vacuum freeze dryer for 40-50 h.

[0020] Furthermore, in the preparation of fibrin, the fibrinogen solution is uniformly mixed with CaCl2, and after solidification, it is frozen at -10-30 ℃ for 1-5 h, and then freeze-dried in a vacuum freeze dryer for 3-48 h.

[0021] Application of a wet adhesive or a method for preparing a wet adhesive in the preparation of materials for the restoration of cultural relics.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0023] In the wet adhesion adhesive of this invention, the phenolic hydroxyl crosslinking properties of tannic acid combined with the active amino acid side chains of silk fibroin construct a wet adhesion network. The introduction of fibrin aggregates enhances adhesion strength, forming an interpenetrating double network structure, giving the adhesive strong wet adhesion properties. Simultaneously, the adhesive exhibits uniform internal stress distribution, effectively preventing localized stress concentration when bonding cracks, thereby reducing secondary damage to fragile artifacts. Its uniform gel texture and strong adhesion allow it to fully fill uneven fracture surfaces, achieving a tight fit, making it particularly suitable for precision repair of complex shapes or micro-cracks. Furthermore, its amorphous, phase-separation-free stable structure results in a slower and more uniform aging process, reducing the likelihood of yellowing, crystallization, or delamination, thus contributing to the long-term stability of the repaired area. These characteristics of the adhesive of this invention collectively make STF a potentially excellent repair material that balances operability, repair durability, and long-term safety.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. Furthermore, in order to make the above contents, objectives, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation process of the STF hydrogel of this invention.

[0026] Figure 2These are physical images and microscopic morphology diagrams of the STF of this invention.

[0027] Figure 3 The STF structure characterization of this invention includes (A) infrared spectroscopy; (B) molecular structure; and (C) X-ray photoelectron spectroscopy.

[0028] Figure 4 This is an example of the original form of stone artifacts, porcelain artifacts, and wooden artifacts in Experiment 2 of this invention, and the effect of STF bonding.

[0029] Figure 5 This is a test image of STF adhering to biological tissues and inorganic materials underwater in Test Example 3 of this invention.

[0030] Figure 6 This invention relates to the adhesion strength test of STF on biological tissues. (A) shows a schematic diagram and actual image of the adhesion strength test of STF on blood vessels; (B) shows the adhesion strength of STF on pig skin and blood vessels.

[0031] Figure 7 This invention relates to a 180° peel test on STF biomaterials. (A) shows a schematic diagram and physical image of the STF peel test on blood vessels; (B) shows the peel test results of STF on pig skin and blood vessels. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0033] In addition, unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be obtained by purchasing them from the market or prepared by existing methods.

[0034] To address the challenges of current artifact restoration adhesives, such as long curing times, lack of wet adhesion, susceptibility to mold and yellowing, and difficulty in adhering to various substrates (stone, porcelain, and wooden artifacts), this invention proposes a hydrogel adhesive that enables rapid wet adhesion for the restoration of unearthed, wet artifacts. The preparation process is illustrated in the flowchart below. Figure 1 First, the phenolic hydroxyl cross-linking properties of tannic acid, combined with the active amino acid side chains of silk fibroin, construct a wet adhesion network. Second, fibrin aggregates are introduced to enhance adhesion strength, forming an interpenetrating double network structure, thus designing a hydrogel adhesive with strong wet adhesion properties. The specific preparation process is as follows:

[0035] Preparation of silk fibroin sponge: Degummed silk fibroin and water were used at a mass ratio of 1:12-30 and dissolved in 9.8-20.8 mol / L lithium bromide. The mixture was then stirred in a water bath at 50-70℃ for 3-5 hours, filtered through eight layers of gauze, dialyzed in deionized water for three days using dialysis bags, with the water changed three times a day, and then frozen in a freezer at -60-100℃ for 40-50 hours using a vacuum freeze dryer.

[0036] Preparation of silk fibroin solution: Add water or buffer solution to silk fibroin sponge and dissolve it under stirring or heating conditions. After complete dissolution, a silk fibroin solution with a mass fraction of 10-50 wt% is obtained. Store in a sealed container at 1-7°C for 0-12 hours for later use.

[0037] Preparation of tannic acid solution: Add water or acidic buffer solution to tannic acid and dissolve it under stirring and light protection. After complete dissolution, a tannic acid solution with a mass fraction of 10-50 wt% is obtained. The resulting solution should be sealed and stored in the dark.

[0038] Preparation of fibrin:

[0039] (1) Preparation and pretreatment of plasma: Centrifuge fresh anticoagulated pig blood at 1000-8000 rpm for 5-20 minutes at 1-8°C. Carefully aspirate the supernatant (pale yellow plasma), avoiding contact with the blood cell precipitate at the bottom. If necessary, centrifugation can be repeated once to obtain clearer plasma.

[0040] (2) Separation of fibrinogen: Mix the fibrinogen solution with CaCl2 (molar concentration of 0.111-0.555 M) evenly, and freeze at -10-30 ℃ for 1-5 h after solidification, and then freeze dry in a vacuum freeze dryer for 3-48 h.

[0041] Preparation of silk fibroin tannic acid adhesive (STF): Weigh 10-100 mg of fibroin and dissolve it in 10-60 mL of silk fibroin solution. Stir to disperse the fibroin evenly, then add 10-60 mL of tannic acid and react for 1-10 min. Stir until cross-linked into an adhesive, then soak in 3-7 wt% tannic acid solution (sealed and protected from light).

[0042] Example 1

[0043] A method for preparing a wet adhesion adhesive, comprising:

[0044] 1. Preparation of silk fibroin sponge: Measure 120 mL of water into a beaker, then weigh 96.85 g of lithium bromide and 10 g of degummed silk and dissolve them in deionized water. Stir in a 60℃ water bath for 4 h. Filter through eight layers of gauze. Dialyze in deionized water using a dialysis bag for three days, changing the water three times a day. After freezing in a -80℃ freezer, finally freeze-dry for 48 h using a vacuum freeze dryer.

[0045] 2. Preparation of silk fibroin solution: Weigh 1.25 g of silk fibroin sponge into a beaker, add 5 mL of deionized water while stirring. After the silk fibroin sponge is completely dissolved, 5 mL of 20% silk fibroin solution is obtained. Store in a sealed container at 4°C for later use. (The silk fibroin solution should not be stored in a 4°C refrigerator for more than 12 hours, otherwise the silk fibroin will denature and become inactive, and will not be able to crosslink with tannic acid.)

[0046] 3. Preparation of tannic acid solution: Weigh 15 g of tannic acid into a beaker, and use a graduated cylinder to measure 35 mL of deionized water and add it to the beaker while stirring until the tannic acid is completely dissolved. This will give you 50 mL of 30% tannic acid solution. Seal and store in a cool, dark place for later use.

[0047] 4. Preparation of fibrin

[0048] (1) Preparation and pretreatment of plasma: Centrifuge fresh anticoagulated pig blood at 3000 rpm for 10 minutes at 4°C. Carefully aspirate the supernatant (pale yellow plasma), avoiding contact with the blood cell precipitate at the bottom. If necessary, centrifugation can be repeated once to obtain clearer plasma.

[0049] (2) Separation of fibrinogen: Mix 50 mL of fibrinogen solution with 5 mL of CaCl2 (0.222M) evenly, freeze at -20 ℃ for 3 h after solidification, and then freeze dry in a vacuum freeze dryer for 12 h.

[0050] 5. Preparation of silk fibroin tannic acid adhesive (STF): Weigh 0.075 g of fibroin and dissolve it in 3 mL of silk fibroin solution. Stir to disperse the fibroin evenly in the silk fibroin solution. Then add 3 mL of tannic acid. After reacting for 1 min, stir until cross-linked into an adhesive. Soak in 5 wt% tannic acid solution for later use (sealed and protected from light).

[0051] like Figure 2As shown, STF appears macroscopically as a pale yellow gel with a uniform texture and significant viscosity. Microscopic observation under a scanning electron microscope (SEM) reveals a dense, smooth, amorphous surface without obvious crystalline structure or microphase separation, exhibiting typical homogeneous characteristics of an amorphous polymer gel. This unique homogeneous and amorphous structure is a significant advantage for its use in artifact restoration: Firstly, the dense and smooth microstructure indicates uniform internal stress distribution, effectively preventing localized stress concentration when bonding cracks, thus reducing secondary damage to fragile artifacts. Secondly, the uniform gel texture and strong viscosity allow it to fully fill uneven fracture surfaces, achieving a tight fit, making it particularly suitable for precision repairs of complex shapes or micro-cracks. Thirdly, its amorphous and stable structure suggests a slower and more uniform aging process, reducing the likelihood of yellowing, crystallization, or delamination, thus contributing to the long-term stability of the repaired area. These characteristics collectively make STF a potentially excellent restoration material that balances operability, repair durability, and long-term safety.

[0052] Experimental Example 1

[0053] To investigate the role of tannic acid in the gelation process of silk fibroin and fibroin, we used Fourier transform infrared spectroscopy (FTIR) to analyze the conformational changes of silk fibroin. Figure 3 As shown in Figure A, in a pure silk fibroin solution, the concentration is located at 1643 cm⁻¹. -1 An absorption peak generated by the C=O stretching vibration in the amide I region was observed, which is a typical characteristic of random coil structures. When fibroin reacts with tannic acid to form SF-TA, the aforementioned absorption peak of fibroin shifts to 1655 cm⁻¹. -1 This indicates that a β-sheet structure has been formed. Figure 3 A).

[0054] Specifically, tannic acid can bind to the active amino acid side chains on silk fibroin and fibroin through non-covalent bonds such as hydrogen bonds, and promote the transformation of silk fibroin from a disordered state to an ordered β-sheet structure through the π-π stacking effect. Research results on STF hydrogels show that at 1041 cm⁻¹... -1 and 1655 cm -1 Absorption peaks were detected at [locations to be inserted here], representing the vibration of the tannin phenolic hydroxyl group and the C=O stretching vibration of the amide bond between silk fibroin and fibroin, respectively. Figure 3 A). These changes in the positions of the absorption peaks are likely due to hydrogen-bonded interactions between tannic acid and silk fibroin and fibroin. Figure 3 B).

[0055] In the N1s spectrum of STF, the peak at 399.8 eV represents an amide bond (HN-(C=O)-), while after crosslinking with tannic acid, a new peak appears at 401.8 eV, protonating the amide / amino group of silk fibroin to form an imine bond -C=NC- ( Figure 3 C).

[0056] Experimental Example 2

[0057] To verify the practical application effectiveness of STF materials in the protection of complex, fragile, and heterogeneous cultural heritage, this experiment selected three types of materials with the most representative physical and chemical properties in archaeological excavations and museum collections—stone tools, porcelain, and wood—as restoration objects, and systematically evaluated the comprehensive effect of STF materials on the restoration of their morphological integrity and enhancement of their mechanical properties.

[0058] This experiment used three types of artifact simulation samples with typical damage characteristics. First, sandstone or limestone fragments with rough surfaces, high micropores, and high brittleness were selected to simulate the fracture of archaeological stone tools. Second, fragments of celadon or white porcelain with smooth, dense glazes and relatively porous bodies were used to simulate the chipping or fracture of vessels. Finally, aged pine or oak fragments were used to simulate cracking of ancient wooden components due to shrinkage, swelling, or biodegradation. All samples underwent standardized pretreatment such as cleaning and drying to simulate real-world restoration scenarios. The restoration process strictly adhered to the principles of "reversibility and minimal intervention," using STF material as an adhesive for bonding.

[0059] like Figure 4 As shown in Figure A, the original damaged state of three types of simulated artifacts is displayed: rough and uneven fracture surfaces of stone tools, sharp edges of cracked porcelain shards, and wood cracks along the grain. The right side shows the state after restoration using STF material. Before curing, STF material exhibits excellent wettability and thixotropy, effectively filling the microscopic unevenness of various materials (from the porous surface of stone tools to the smooth glaze of porcelain), achieving precise alignment and seamless bonding of fracture surfaces. The cured STF material is transparent or can be slightly adjusted to match the background color of the artifact, with no obvious reflection or color difference, preserving the original appearance and historical texture of the artifact to the greatest extent possible, meeting the aesthetic and ethical requirements of "restoring the old as it was" in restoration projects. The restored artifact samples have a stable overall shape, with no obvious deformation or misalignment, restoring their structural integrity as historical evidence.

[0060] To quantitatively evaluate the mechanical reinforcement effect of the repaired area, this experiment designed a standardized static load-bearing test. Figure 4B). The restored artifact sample was placed horizontally, and a vertical load was gradually applied at a constant rate above the center of the adhesive joint until signs of adhesive failure or cracking of the artifact were observed. The maximum safe load-bearing capacity was recorded. The restored artifact maintained structural integrity and morphological stability, and the load-bearing capacity of the adhesive joint was verified. Figure 4 (B) The restored stone, porcelain and wooden artifacts can bear weights of 0.885 kg, 0.810 kg and 0.700 kg respectively, demonstrating the technical advantages of STF material in artifact restoration, which combines bonding strength and durability.

[0061] Experimental Example 3

[0062] The key objective of this experiment is to verify the general adhesion performance and stability of the prepared STF (biomimetic adhesion material) in complex underwater environments. To comprehensively and systematically evaluate its performance, we designed a series of rigorous underwater adhesion experiments, selecting substrate materials with different surface chemistry, wettability, elastic modulus, and surface roughness to simulate various interfaces that may be encountered in real-world underwater applications. To verify the underwater adhesion stability of the STF, experiments were conducted underwater using ex vivo biological tissues (heart, liver, spleen, lung, kidney) and inorganic materials (pebbles, plastics, metals, rubber, and glass) as adhesion substrates. Figure 5 This study demonstrates that STF can firmly adhere to the surfaces of various biological tissues and inorganic materials underwater, indicating that STF possesses good substrate adaptability and stable underwater adhesion capabilities. The experimental results show that STF exhibits long-lasting underwater wet adhesion stability, while maintaining its structural integrity and stability underwater.

[0063] Test Example 4

[0064] Using a universal testing machine, and referring to standards such as ASTM F2255 or ISO 4587, the overlap shear test was performed on the adhesion interface between STF and biological tissue. The specific steps are as follows ( Figure 6 A): Prepare STF specimens of standard dimensions (e.g., length × width: 25 mm × 10 mm, uniform thickness). Trim excised porcine skin or porcine vascular tissue to the same dimensions and fix them in the upper and lower clamps of the testing machine, so that the STF specimen and the tissue specimen form an overlap joint with a specified overlap area (e.g., 10 mm × 10 mm). The test is conducted under simulated physiological conditions (e.g., 37°C, humid conditions), applying shear force at a constant tensile rate (e.g., 20 mm / min) until the adhesion interface completely fails. The maximum shear strength (unit: kPa), i.e., the adhesion strength, is calculated from the force-displacement curve. Each experiment is repeated at least 3 times, and the results are expressed as mean ± standard deviation.

[0065] To assess the adhesion strength of STF to biological tissues, lap shear tests were performed using a universal tensile testing machine.Figure 6 A). Pig skin is highly similar to human skin in epidermal thickness, dermal collagen fiber structure and arrangement, elastin content, and subcutaneous fat layer distribution, and its mechanical response (such as elastic modulus and tensile strength) is close to that of human skin. Pig blood vessels (such as the carotid artery or aorta) are also the gold standard model for studying cardiovascular tissue mechanics and adhesion, in terms of their layered structure (intima, media, adventitia), collagen and elastic fiber composition, and overall flexibility. Therefore, pig skin and isolated pig blood vessels were chosen as adhesion testing models to simulate human skin and blood vessels. Figure 6 As shown in Figure B, the adhesion strength of STF on the corresponding tissues was 36.38 ± 2.59 kPa and 39.35 ± 1.90 kPa, respectively. It is noteworthy that the adhesion strength of STF on vascular tissue was higher than that on porcine skin, which may be attributed to the fact that STF more readily forms stable adhesion on the fibrous structure of the adventitia of blood vessels.

[0066] Experimental Example 5

[0067] This experiment strictly follows international standards such as ASTM F2456 or ISO 8510, and performs a 180° peel test on the STF-biological tissue interface using a universal testing machine. The test procedure is as follows: An STF sample is prepared into a strip of standard width (e.g., 25 mm wide). One end is bonded to a standard-treated detached porcine skin or porcine blood vessel substrate (flat and fixed on a rigid platform) to form a specified adhesion area (e.g., 25 mm × 50 mm). The free end of the sample is folded upwards 180° and clamped in the moving fixture of the testing machine. The test is conducted in a humid environment simulating physiological conditions, peeling vertically upwards at a constant peel rate (e.g., 20 mm / min). The average work done per unit width during peeling, i.e., peel work (unit: J m⁻²), is calculated using the simultaneously recorded force-displacement curves. This index comprehensively reflects the interfacial adhesion strength and the material's deformation energy dissipation capacity, and is a key parameter for evaluating the adhesive's peel resistance. Each experiment is repeated at least 5 times, and the data are presented as mean ± standard deviation.

[0068] The 180° peel test is another important standard for evaluating the adhesion performance of STF. In this experiment, porcine skin and isolated vascular tissue were used as peel test models. Figure 7 A). For example Figure 7The peeling work of the STF shown in Figure B on the corresponding tissues was 338.06 ± 1.70 J m⁻² and 225.33 ± 32.57 J m⁻², respectively. Furthermore, the peeling work of the STF on porcine skin was slightly higher than that on vascular tissue. This difference is mainly attributed to the different number of interfacial hydrogen bond interactions. The surface of porcine skin is rich in polar groups (such as hydroxyl and carboxyl groups), which facilitates the interaction of functional groups such as phenolic hydroxyl groups in the STF to form more hydrogen bonds, thereby enhancing interfacial adhesion. On the surface of blood vessels, there are relatively fewer polar groups available for hydrogen bond formation, resulting in a moderate reduction in interfacial hydrogen bond interactions. This moderate adhesion strength ensures effective sealing of the material under bleeding conditions and also helps to reduce damage to vascular tissue during subsequent patch removal.

[0069] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0070] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A wet adhesion adhesive, characterized in that, This includes compounds containing phenolic hydroxyl groups, silk fibroin, and fibroin.

2. The wet adhesion adhesive as described in claim 1, characterized in that: The compound containing phenolic hydroxyl groups uses tannic acid, with a volume ratio of tannic acid to silk fibroin of 1:

1.

3. The wet adhesion adhesive as described in claim 2, characterized in that: Fibrin accounts for 2-3 wt% of the adhesive.

4. The wet adhesion adhesive as described in claim 3, characterized in that: The concentration of silk fibroin is 10-50 wt%, and the concentration of tannic acid is 10-50 wt%.

5. The wet adhesion adhesive as described in claim 4, characterized in that: The concentration of silk fibroin was 20 wt%, the concentration of tannic acid was 30 wt%, and the proportion of fibroin in the adhesive was 2.4 wt%.

6. A method for preparing a wet adhesion adhesive as described in any one of claims 1-5, characterized in that: include: Preparation of silk fibroin solution: Add solvent to silk fibroin sponge, and after complete dissolution, obtain silk fibroin solution, seal and store for later use; Preparation of a solution containing phenolic hydroxyl groups: Add a solvent to the compound containing phenolic hydroxyl groups, and after complete dissolution, obtain a solution containing phenolic hydroxyl groups. Seal and store for later use. Preparation of fibrin: Mix fibrinogen solution with CaCl2 evenly, freeze after solidification, and freeze-dry. Preparation of adhesive: Fiber protein is dissolved in silk fibroin solution, the fiber protein is stirred and dispersed, then a compound containing phenolic hydroxyl groups is added and reacted, and stirred until cross-linked into an adhesive, which is then soaked in tannic acid solution.

7. The method for preparing a wet adhesion adhesive as described in claim 6, characterized in that: In preparing the silk fibroin solution, the solvent is water or buffer solution. The dissolution process is carried out under stirring or heating conditions. The resulting silk fibroin solution is stored in a sealed refrigerator at 1-7°C for 0-12 hours for later use.

8. The method for preparing a wet adhesion adhesive as described in claim 6, characterized in that: The preparation method of silk fibroin sponge includes: using degummed silk fibroin and water at a mass ratio of 1:12-30, dissolving it with 9.8-20.8 mol / L lithium bromide, stirring in a water bath at 50-70℃ for 3-5 h, filtering, dialyzing in deionized water using a dialysis bag, freezing, and then freeze-drying in a vacuum freeze dryer for 40-50 h.

9. The method for preparing a wet adhesion adhesive as described in claim 6, characterized in that: In the preparation of fibrin, the fibrinogen solution is uniformly mixed with CaCl2, and after solidification, it is frozen at -10-30 ℃ for 1-5 h, and then freeze-dried in a vacuum freeze dryer for 3-48 h.

10. The application of a wet adhesive as described in any one of claims 1-5 or a method for preparing a wet adhesive as described in any one of claims 6-9 in the preparation of materials for the restoration of cultural relics.

Images