Adhesive compound with adhesive property optimized based on metal hydroxide as well as preparation method and application of adhesive compound

Abstract

The invention discloses an adhesive compound with an adhesive property optimized based on metal hydroxides as well as a preparation method and application of the adhesive compound, and belongs to the technical field of biological adhesives. The present invention relates to an adhesive composition comprising an adhesive precursor consisting of a protein-polyphenol composite hydrogel and a hydrogen bond destructive small molecule compound capable of network reconstitution comprising beta-folding formation in aqueous phase grafting comprising a metal hydroxide having the characteristics of: (a) a hydration enthalpy value of from-1000 kJ / mol to-4000 kJ / mol; (b) a dissociation constant of from 6 pKa to 13.5 pKa; (c) a water exchange rate of 105 S <-1 > to 10 < 10 > S <-1 >. The adhesion compound can be networked to form an advanced structure when encountering water, not only can generate underwater lap joint shear strength of more than 1MPa, but also can tolerate underwater long-term soaking and temperature change from-196 DEG C to 100 DEG C, and meanwhile, the adhesion compound also has good biocompatibility, can meet the requirement of the environment in a human body on tissue adhesion safety, and has good application prospects. Stability suitable for in vivo tissue repair and industrial applications is exhibited.

Description

Technical Field

[0001] This application belongs to the field of bio-based adhesive technology, and specifically relates to an adhesive composite with optimized adhesion performance based on metal hydroxide, its preparation method and application. Background Technology

[0002] Adhesives are widely used in marine engineering, biomedicine, and automotive manufacturing. However, traditional adhesives heavily rely on petroleum-based polymers such as epoxy resins, acrylates, and polyurethanes. When used in the biomedical field, the complex fluid media in the human body, including blood and tissue fluid, can easily cause traditional adhesives to fail due to interference with the hydration layer. Furthermore, the high biosafety requirements for use in the human body limit the clinical application of traditional adhesives due to residual toxic crosslinking agents such as aldehydes. Therefore, developing a bio-adhesive that maintains high-strength adhesion in a water-rich physiological environment, possesses excellent biosafety, and is tolerated by the human body and can even promote tissue regeneration has become an urgent need in the fields of clinical medicine and biomaterials.

[0003] Currently, related fields have developed bio-based adhesives with excellent adhesion properties using polymers and polyphenols as raw materials. For example, patent technology with publication number CN 117323462 A discloses the preparation of an adhesive composite hydrogel by constructing an adhesive composite hydrogel using silk fibroin and tannic acid, and then mixing the adhesive composite hydrogel with urea or guanidine hydrochloride to obtain an adhesive hydrogel with excellent injection performance, effectively meeting the bio-adhesion needs of the biomedical field.

[0004] However, existing bio-based adhesives, such as those mentioned above, generally suffer from insufficient adhesion performance (especially underwater adhesion strength, which is usually <1MPa), durability, and long-term stability. They are particularly difficult to balance the long-lasting adhesion in dynamic bodily fluid flushing environments with the safety of human tissues, and cannot meet the needs of harsh environments such as tissue repair in the human body, underwater operations, and aerospace. Summary of the Invention

[0005] This application discloses an adhesion complex based on metal hydroxide to optimize adhesion performance, its preparation method, and its application, which effectively solves the technical problems of insufficient underwater adhesion performance, durability, and long-term stability of existing bio-based adhesives.

[0006] To achieve the above objectives, the technical solution provided in this application is as follows:

[0007] The first aspect of this application provides an adhesion composite based on metal hydroxide to optimize adhesion performance, the adhesion composite comprising an adhesion precursor and a metal hydroxide in a mass ratio of 100:1 to 100.

[0008] The adhesion precursor is composed of a protein-polyphenol composite hydrogel and a hydrogen bond-breaking small molecule compound, and the adhesion precursor can undergo network reconstruction involving β-sheet formation in an aqueous phase containing the metal hydroxide.

[0009] The metal hydroxide has the following characteristics:

[0010] (a) Hydration enthalpy values ​​from -1000 kJ / mol to -4000 kJ / mol;

[0011] (b) Dissociation constants from 6 pKa to 13.5 pKa; and

[0012] (c)10 5 S -1 Up to 10 10 S -1 The water exchange rate.

[0013] According to the preferred disclosure of the first aspect, the metal hydroxide has the following characteristics:

[0014] (a) Hydration enthalpy values ​​ranging from -1309 kJ / mol to -2099 kJ / mol;

[0015] (b) Dissociation constants from 8 pKa to 13.4 pKa; and

[0016] (c)9×10 5 S -1 Up to 5.7×10 9 S -1 The water exchange rate.

[0017] According to the preferred disclosure of the first aspect, the metal hydroxide is selected from hydroxides containing magnesium, calcium, strontium, barium, manganese, cobalt, copper, and zinc.

[0018] According to the preferred disclosure of the first aspect, the protein component in the protein-polyphenol composite hydrogel is selected from at least one of silk fibroin, gelatin, collagen, keratin, soy textured protein, gluten, and fibroin;

[0019] The polyphenol component in the protein-polyphenol composite hydrogel is selected from at least one of tannic acid, dopamine, caffeic acid, tea polyphenols, and anthocyanins.

[0020] According to the preferred disclosure of the first aspect, the hydrogen bond-breaking small molecule compound is selected from at least one of urea, guanidine hydrochloride, and thiourea.

[0021] According to a preferred disclosure of the first aspect, the mass ratio of the adhesion precursor to the metal hydroxide is 100:15 to 100.

[0022] According to a preferred disclosure of the first aspect, the adhesion precursor comprises a solution and a powder.

[0023] According to the preferred disclosure of the first aspect, after the adhesive compound has been fully cured, the lap shear strength, as measured by ASTM F2255-24, is greater than 1 MPa.

[0024] The second aspect of this application also discloses a method for preparing the adhesion composite with optimized adhesion properties based on metal hydroxide, comprising:

[0025] An adhesion precursor is prepared by mixing a protein-polyphenol composite hydrogel with a hydrogen bond-breaking small molecule compound; and the adhesion precursor is mixed with a metal hydroxide to form an adhesion complex.

[0026] The third aspect of this application also discloses the application of the adhesion complex based on metal hydroxide with optimized adhesion properties described above in this application in biomedical bonding, fixation and repair of bone tissue, bonding and repair of underwater structures, marine engineering, aerospace component assembly, automobile manufacturing, and electronic component packaging.

[0027] Compared with the prior art, the advantages or beneficial effects of this application include at least:

[0028] The adhesion complex provided in this application introduces a metal hydroxide with suitable thermodynamics and kinetics into an adhesion precursor composed of a protein-polyphenol composite hydrogel and hydrogen bond-breaking small molecule compounds. This effectively promotes a controllable and moderate interaction between the metal ions and the adhesion precursor, thereby directionally driving the adhesion precursor to dynamically balance and reconstruct a network including β-sheet formation, generating a denser higher-order structure to achieve a curing effect. Simultaneously, it significantly enhances the cohesive force of the cured adhesion complex, endowing it with excellent adhesion performance and stability. It achieves an underwater steel-to-steel lap shear strength of over 1 MPa and maintains extremely high adhesion strength even after long-term immersion in water (over one year). These characteristics enable the adhesion complex to overcome water molecule interference in the moist environment of the human body filled with blood and bodily fluids, achieving strong adhesion and closure of soft tissues or bones, avoiding adhesion failure caused by bodily fluid erosion. Furthermore, it can withstand extreme temperature changes from -196 to 100°C and the erosion of organic solvents. First, it exhibits industrial-grade stability; second, the curing process driven by the above metal hydroxides requires no external energy input, giving the adhesive compound excellent self-curing ability, effectively achieving "zero-energy" self-curing with energy self-sufficiency. Furthermore, all components of the adhesive compound are widely available, low-cost, environmentally friendly, highly biosafe, and non-toxic, meeting the strategic requirements of green environmental protection and carbon neutrality. It is also highly suitable for adhesive applications in the moist environment of the human body and effectively reduces the risk of postoperative inflammation and immune rejection. Third, this adhesive compound can directly replace traditional petroleum-based adhesives in high-value industrial fields with extremely stringent performance requirements, such as marine engineering, underwater repair, aerospace, automotive manufacturing, and precision electronic packaging. Fourth, this adhesive compound possesses good biocompatibility and component compatibility, safely bonding human tissue and constructing tissue adhesives that integrate long-term fixation and treatment functions within the human body, achieving the effect of promoting tissue healing while providing early mechanical support, making it suitable for high-end biomedical fields. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The underwater steel-steel lap shear strength test results for adhesion complexes and compositions with different metal hydroxides added;

[0031] Figure 2 Strain scanning rheological diagrams of the STU adhesion precursor and adhesion composites with different amounts of Mg(OH)2 added before curing;

[0032] Figure 3 Injection force curves of STU adhesion precursor and adhesion complexes with different amounts of Mg(OH)2 before curing;

[0033] Figure 4 Strain scanning rheological diagrams of STU adhesion precursor and adhesion complexes with different amounts of Mg(OH)2 after immersion and curing in water for 24 hours;

[0034] Figure 5 Scanning electron microscope images of the STU adhesion precursor and the adhesion complex 15wt%Mg(OH)2 / STU before and after curing;

[0035] Figure 6 The diagram shows the protein secondary structure content of the STU adhesion precursor and adhesion complex 15wt%Mg(OH)2 / STU before and after curing.

[0036] Figure 7 Comparison of lap shear strength of adhesion complexes x·wt%Mg(OH)2 / STU with different Mg(OH)2 content after 24 hours of underwater bonding;

[0037] Figure 8 The curves showing the change in lap shear strength of the adhesion composite 15wt%Mg(OH)2 / STU during long-term (1 day, 1 month, 6 months and 1 year) underwater immersion process.

[0038] Figure 9 Comparison of lap shear strength of the adhesion composite 15wt%Mg(OH)2 / STU after treatment at different temperatures (-196℃, 0℃, 25℃ and 100℃) for 24 hours.

[0039] Figure 10 Comparison of the overlap shear strength of protein-polyphenol composite hydrogels prepared for different proteins after immersion and curing in water for 24 hours. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort are within the scope of protection of this application.

[0041] In the following description of this application, the term "and / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. Here, A and B can be singular or plural; the symbol " / " means "or".

[0042] In the following description of this application, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions mean any combination of such items, including any combination of single or multiple items. For example, "at least one of A, B or C" or "at least one of A, B and C" can mean any one of A, B, and C, or A+B, or A+C, or B+C, or A+B+C, where A, B, and C can be single or multiple.

[0043] In the following description of this application, the order of the sequence numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be specifically determined by its function and internal logic, and does not constitute any limitation on the execution process of this embodiment.

[0044] In the following description of this application, the numerical range should be understood to also specifically disclose each intermediate value between the upper and lower limits of the range. Any intermediate value within a stated range, as well as any other stated value or each smaller range between intermediate values ​​within a stated range, are also included in this embodiment, and the upper and lower limits of the smaller ranges may be independently included or excluded from the range.

[0045] Unless otherwise stated, the technical / scientific terms used in this application have the meanings commonly understood by one of ordinary skill in the art. While this application describes only preferred materials and methods, similar or equivalent methods and materials may be used in specific embodiments or test cases. All references to this application 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 application shall prevail.

[0046] To address the shortcomings of existing bio-based adhesives in terms of underwater adhesion performance, durability, and long-term stability, as well as the difficulty in achieving sustained adhesion under dynamic bodily fluid flushing conditions, the first aspect of this application provides an adhesion complex based on metal hydroxide to optimize adhesion performance. This complex comprises an adhesion precursor and a metal hydroxide in a mass ratio of 100:1 to 100. The adhesion precursor is composed of a protein-polyphenol composite hydrogel and a hydrogen bond-breaking small molecule compound, and can undergo network reconstruction involving β-sheet formation in an aqueous phase containing the metal hydroxide. The metal hydroxide has the following characteristics: (a) a hydration enthalpy of -1000 kJ / mol to -4000 kJ / mol; (b) a dissociation constant of 6 pKa to 13.5 pKa; and (c) a dissociation constant of 10... 5 S -1 Up to 10 10 S -1 The water exchange rate.

[0047] It should be noted that the adhesion precursor described in this application refers to a protein-polyphenol composite hydrogel prepared from proteins and polyphenol compounds, which is then physically mixed with a hydrogen bond-breaking small molecule compound. This application does not specifically limit the preparation strategy of the protein-polyphenol composite hydrogel; any mature preparation technology known in the art can be used. Of course, in order to enable the adhesion precursor to undergo network reconstruction involving β-sheet formation in an aqueous phase containing the metal hydroxide, those skilled in the art should understand that the proteins in the protein-polyphenol composite hydrogel possess β-sheet potential.

[0048] This application introduces a metal hydroxide with suitable thermodynamics and kinetics into an adhesion precursor composed of a protein-polyphenol composite hydrogel and a hydrogen-bonding-disrupting small molecule compound. This effectively promotes a controllable and moderate interaction between the metal ions and the adhesion precursor, thereby directionally driving the dynamic equilibrium of the adhesion precursor to undergo network reconstruction involving β-sheet formation and generating a denser higher-order structure to achieve a curing effect. This significantly enhances the cohesive force of the cured adhesion composite, endowing it with excellent adhesion performance and stability. It achieves an underwater steel-to-steel lap shear strength of over 1 MPa and maintains extremely high adhesion strength even after long-term immersion in water (over one year). These characteristics allow the adhesion composite to overcome water molecule interference in the moist environment of the human body filled with blood and body fluids, achieving strong adhesion and closure of soft tissues or bones, avoiding adhesion failure caused by body fluid erosion. Furthermore, it can withstand extreme temperature changes from -196°C to 100°C and the erosion of organic solvents, demonstrating… The adhesive compound exhibits several advantages: firstly, it possesses industrial-grade stability; secondly, the curing process driven by the aforementioned metal hydroxides requires no external energy input, enabling the compound to achieve excellent self-curing capabilities and effectively achieve "zero-energy" self-curing. Furthermore, all components of the adhesive compound are readily available, low-cost, environmentally friendly, highly biosafe, and free of toxic side effects, meeting the strategic requirements of green environmental protection and carbon neutrality. It is also highly suitable for adhesive applications in the moist environment of the human body, effectively reducing the risk of postoperative inflammation and immune rejection; thirdly, this adhesive compound can directly replace traditional petroleum-based adhesives in high-value industrial fields with extremely stringent performance requirements, such as marine engineering, underwater repair, aerospace, automotive manufacturing, and precision electronic packaging; and fourthly, this adhesive compound possesses good biocompatibility and component compatibility, enabling safe bonding of human tissue and the construction of tissue adhesives that combine long-term fixation and therapeutic functions within the human body, promoting tissue healing while providing early mechanical support, making it suitable for high-end biomedical applications.

[0049] In possible disclosed examples, the metal hydroxides of this application are preferably hydroxides containing magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), manganese (Mn), cobalt (Co), copper (Cu), and zinc (Zn). Hydroxides containing these metal ions meet the required thermodynamic and kinetic requirements, effectively promoting a controllable and moderate interaction between the metal ions and the adhesion precursor. This directionally drives the dynamic equilibrium of the adhesion precursor to undergo network reconstruction and generate a denser, higher-order structure for solidification. Specific thermodynamic and kinetic data are shown in Table 1.

[0050] Table 1: Thermodynamics and Kinetics of Preferred Metal Ions

[0051]

[0052] It should be noted that the embodiments of this application select Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Mn(OH)2, Co(OH)2, Cu(OH)2, and Zn(OH)2 as representatives for exemplary description because these metal hydroxides are relatively common, inexpensive, and readily available, facilitating large-scale verification. However, this does not constitute any limitation on the scope of protection of this application. Other metal hydroxides that satisfy the aforementioned thermodynamics and kinetics fall within the scope of protection of this application, and will not be listed individually here.

[0053] Based on the above preferred examples, the metal hydroxide described in this application more preferably has the following characteristics:

[0054] (a) Hydration enthalpy values ​​ranging from -1309 kJ / mol to -2099 kJ / mol;

[0055] (b) Dissociation constants from 8 pKa to 13.4 pKa; and

[0056] (c)9×10 5 S -1 Up to 5.7×10 9 S -1 The water exchange rate.

[0057] In possible public examples, the protein components of the protein-polyphenol composite hydrogel described in this application may be selected from silk fibroin, gelatin, collagen, keratin, soy textured protein, gluten, and fibroin, etc., and the polyphenol components may be selected from tannic acid, dopamine, caffeic acid, tea polyphenols, and anthocyanins, etc.; meanwhile, the hydrogen bond-breaking small molecule compounds may be selected from urea, guanidine hydrochloride, and thiourea, etc. Therefore, the adhesion precursors that may be selected in the embodiments of this application include silk fibroin-tannic acid-urea adhesion precursor, gelatin-tannic acid-urea adhesion precursor, silk fibroin-tannic acid-guanidine hydrochloride adhesion precursor, silk fibroin-caffeic acid-urea adhesion precursor, and gelatin-anthocyanin-urea adhesion precursor, etc. In this application, the silk fibroin-tannic acid-urea adhesion precursor is selected as a representative example for illustrative description because its preparation is simple and mature, and it is easy to scale up for verification. However, this does not constitute any limitation on the scope of protection of this application. Any other adhesion precursor that conforms to the technical mechanism of this application falls within the scope of protection of this application, and this application will not list them one by one.

[0058] In possible public examples, the preferred mass ratio of the adhesion precursor to the metal hydroxide in this application is 100:15 to 100 to improve the underwater overlap shear strength. Specifically, this application uses mass ratios of 100:1, 100:5, 100:15, 100:30, 100:45, 100:60, 100:75, 100:90, and 100:100 as representative examples because these ratios uniformly cover the lower, middle, and upper limits of the aforementioned preferred range, comprehensively and intuitively verifying the technical effects within this ratio range, facilitating understanding by those skilled in the art. However, this does not constitute any limitation on the scope of protection of this application. Any other ratio falling within the 100:1 to 100 range is within the scope of protection of this application, and will not be listed individually here.

[0059] In possible disclosed examples, the adhesion precursor of this application is preferably in solution or powder form. For example, when the STU adhesion precursor is in solution form, it can be formed by mixing SF (silk fibroin) solution and TA (tannic acid) solution and stirring at room temperature until an ST composite hydrogel is formed, and then mixing the ST composite hydrogel with urea powder and stirring at room temperature until a homogeneous viscous liquid of STU adhesion precursor is formed for direct use; when the STU adhesion precursor is in powder form, the formed viscous liquid of STU adhesion precursor can be processed into powder form for later use, for example, after freeze-drying the viscous liquid of STU adhesion precursor, the freeze-dried block is successively ground and sieved to obtain a homogeneous STU adhesion precursor powder.

[0060] It should be noted that this application does not impose any special limitations on the concentration and mixing ratio of SF solution and TA solution, as long as the ST composite hydrogel can be formed. The example described in this application uses 10wt% SF solution and 10wt% TA solution as raw materials, mixed at a volume ratio of 1:4 to prepare the ST composite hydrogel, because the network structure of the ST composite hydrogel prepared at this concentration ratio is relatively the best, allowing for direct verification of the technical effect after adding metal hydroxide, and facilitating understanding by those skilled in the art. However, this does not constitute any limitation on the concentration and mixing ratio of SF solution and TA solution in this application. Other concentrations and mixing ratios that achieve the same or similar technical effects are acceptable, and will not be listed individually in this application.

[0061] It should be noted that this application does not have a specific limitation on the mixing ratio of the ST composite hydrogel and urea powder. The goal is to achieve the regulation of the ST composite hydrogel network structure and form a modified hydrogel with target properties (e.g., adhesion, injectability, biocompatibility) through the introduction of urea. Those skilled in the art can flexibly adjust the ratio according to the performance requirements of actual application scenarios. In this application, the embodiment is described exemplarily with a urea powder to dried silk fibroin protein mass ratio of 2:3 because the adhesion precursor formed under this ratio can exhibit good injectability and can also solidify rapidly upon contact with an aqueous environment to form an adhesive structure with good adhesion and support. This facilitates the understanding of the core technology by those skilled in the art, but it does not constitute any limitation on the scope of protection of this application. Any other ratio that can achieve the same or similar technical effects falls within the scope of protection of this application, and will not be listed individually here.

[0062] It should be noted that this application does not specifically limit the strategy or parameters for processing the viscous liquid adhesion precursor into an adhesion precursor powder, as long as a uniform adhesion precursor powder can be prepared. Specifically, when the adhesion precursor is in solution form, the adhesion performance is optimized using a liquid method, i.e., directly mixing the adhesion precursor solution with the metal hydroxide powder; when the adhesion precursor is in powder form, the adhesion performance is optimized using a powder method, i.e., first physically dry-mixing the adhesion precursor powder with the metal hydroxide powder, and then activating it with water or an aqueous solution before use.

[0063] In a second aspect, embodiments of this application also provide a method for preparing the adhesion composite with optimized adhesion properties based on metal hydroxides as described above, which includes the following steps:

[0064] A protein-polyphenol composite hydrogel was mixed with a hydrogen bond-disrupting small molecule compound to prepare an adhesion precursor.

[0065] Additionally, the adhesion precursor is mixed with a metal hydroxide to form an adhesion complex.

[0066] It should be noted that the entire preparation process of this application does not use any organic solvents, and relies entirely on the exothermic efficiency of metal hydroxides to achieve the curing effect. It has the advantages of simple operation, low energy consumption and environmental friendliness, and is suitable for large-scale preparation and field application.

[0067] In a third aspect, embodiments of this application also provide typical applications of the adhesion complex based on metal hydroxide to optimize adhesion performance, specifically using the adhesion complex for biomedical bonding, fixation and repair of bone tissue, bonding and repair of underwater structures, marine engineering, aerospace component assembly, automobile manufacturing, and electronic component packaging.

[0068] The technical solution of this application will be further described below with reference to specific embodiments.

[0069] Example 1

[0070] This example provides an adhesion composite 15wt%Mg(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which is prepared through the following steps:

[0071] S1: Add 10g of tannic acid (TA) powder to 90g of deionized water and stir to dissolve for 1 hour to form a 10wt% TA solution;

[0072] S2: 120g of natural silkworm cocoons were soaked in 10L of 0.02M Na2CO3 solution and boiled for 1 hour. The cocoons were removed, the liquid was discarded, and the soaking and boiling process was repeated three times to obtain degummed silk fibroin fibers. The silk fibroin fibers were washed five times with deionized water and then dried in an oven at 45℃ for 48 hours. The dried silk fibroin fibers were then dissolved in 100mL of 9.3M LiBr solution at 60℃ to form a silk fibroin (SF) solution. The silk fibroin (SF) solution was dialyzed with deionized water for three days (dialysis bag molecular weight 1.4×10⁻⁶). 4 Da), and 15wt% PEG solution were reverse dialyzed for 24h to obtain 10wt% SF solution, wherein the PEG solution was prepared by 300g of 2×10⁻⁶ ppm PEG solution. 4 Da's PEG powder was added to 1700g of deionized water and stirred for 2 hours to form a solution.

[0073] S3: Mix the SF solution and the TA solution at a volume ratio of 1:4 and stir until an ST composite hydrogel is formed. Then mix the ST composite hydrogel with urea powder and stir until a uniform viscous liquid of STU adhesion precursor is formed. The mass ratio of urea powder to dried silk protein is 2:3.

[0074] S4: Add magnesium hydroxide (Mg(OH)2) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor to obtain the adhesion complex 15 wt% Mg(OH)2 / STU.

[0075] Example 2

[0076] This example provides an adhesion composite 15wt%Ca(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0077] Adding calcium hydroxide (Ca(OH)2) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor yields the adhesion complex 15 wt% Ca(OH)2 / STU.

[0078] Example 3

[0079] This example provides an adhesion composite 15wt%Sr(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0080] Adding 15 wt% of strontium hydroxide (Sr(OH)2) powder to the viscous liquid of the STU adhesion precursor yields the adhesion complex 15 wt% Sr(OH)2 / STU.

[0081] Example 4

[0082] This example provides an adhesion composite of 15wt% Ba(OH)2 / STU with optimized adhesion properties based on metal hydroxides. The only difference between this composite and Example 1 is that:

[0083] Adding 15 wt% of barium hydroxide (Ba(OH)2) powder to the viscous liquid of the STU adhesion precursor yields the adhesion complex 15 wt% Ba(OH)2 / STU.

[0084] Example 5

[0085] This example provides an adhesion composite 15wt%Mn(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0086] Adding 15 wt% of manganese hydroxide (Mn(OH)2) powder to the viscous liquid of the STU adhesion precursor yields the adhesion complex 15 wt% Mn(OH)2 / STU.

[0087] Example 6

[0088] This example provides an adhesion composite 15wt%Co(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0089] Adding 15 wt% of cobalt hydroxide (Co(OH)2) powder to the viscous liquid of the STU adhesion precursor yields the adhesion composite 15 wt% Co(OH)2 / STU.

[0090] Example 7

[0091] This example provides an adhesion composite 15wt% Cu(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0092] Adding copper hydroxide (Cu(OH)2) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor yields the adhesion composite 15 wt% Cu(OH)2 / STU.

[0093] Example 8

[0094] This example provides an adhesion composite 15wt%Zn(OH)2 / STU with optimized adhesion properties based on metal hydroxide, which differs from Example 1 only in that:

[0095] Adding zinc hydroxide (Zn(OH)2) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor yields the adhesion complex 15 wt% Zn(OH)2 / STU.

[0096] To illustrate the actual effect of the adhesion complexes prepared in Examples 1-8 above, comparative examples 1-6 of metal hydroxides that do not meet thermodynamic and kinetic requirements are also provided in this application specification.

[0097] Comparative Example 1

[0098] This example provides a 15wt% NaOH / STU composition, which differs from Example 1 only in that:

[0099] Adding sodium hydroxide (NaOH) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor yields a 15 wt% NaOH / STU composition.

[0100] Comparative Example 2

[0101] This example provides a 15wt% KOH / STU composition, which differs from Example 1 only in that:

[0102] Adding 15 wt% potassium hydroxide (KOH) powder to the viscous liquid of the STU adhesion precursor yields a 15 wt% KOH / STU composition.

[0103] Comparative Example 3

[0104] This example provides a 15wt% Cr(OH)3 / STU composition, which differs from Example 1 only in that:

[0105] Adding 15 wt% of chromium hydroxide (Cr(OH)3) powder to the viscous liquid of the STU adhesion precursor yields a 15 wt% Cr(OH)3 / STU composition.

[0106] Comparative Example 4

[0107] This example provides a 15wt% Fe(OH)3 / STU composition, which differs from Example 1 only in that:

[0108] Adding 15 wt% of ferric hydroxide (Fe(OH)3) powder to the viscous liquid of the STU adhesion precursor yields 15 wt% Fe(OH)3 / STU.

[0109] Comparative Example 5

[0110] This example provides a 15wt% Ni(OH)2 / STU composition, which differs from Example 1 only in that:

[0111] Adding nickel hydroxide (Ni(OH)2) powder at 15 wt% of its mass to the viscous liquid of the STU adhesion precursor yields a 15 wt% Ni(OH)2 / STU composition.

[0112] Comparative Example 6

[0113] This example provides a 15wt% Al(OH)3 / STU composition, which differs from Example 1 only in that:

[0114] Adding 15 wt% of aluminum hydroxide (Al(OH)3) powder to the viscous liquid of the STU adhesion precursor yields a 15 wt% Al(OH)3 / STU composition.

[0115] The thermodynamics and kinetics of the metal hydroxides in the above comparative examples are shown in Table 2.

[0116] Table 2: Thermodynamics and Kinetics of Metal Ions in the Comparative Examples

[0117]

[0118] Test Example 1

[0119] Following the ASTM F2255-24 standard method for testing lap shear strength, the adhesive composites and compositions prepared in the above examples and comparative examples were coated between two stainless steel sheets (adhesive area 2.5 cm²), respectively. After curing in an underwater environment for 24 hours, the lap shear strength was tested using a universal testing machine. The results were as follows: Figure 1 As shown. Among them, Figure 1 The results of underwater steel-to-steel lap shear strength tests for various adhesion compounds and compositions are presented.

[0120] according to Figure 1As can be seen, the cured adhesion strength of the adhesion composites prepared in Examples 1-8 is much higher than 1 MPa. However, the compositions provided in Comparative Examples 1-2 failed to reach an adhesion strength of 1 MPa due to the mismatch between hydration enthalpy and dissociation constant; the compositions provided in Comparative Examples 3-4 and 6 also failed to reach an adhesion strength of 1 MPa due to the mismatch of various parameters; and the composition provided in Comparative Example 5 also failed to reach an adhesion strength of 1 MPa due to the mismatch in water exchange rate. Therefore, only by adding a composite that simultaneously satisfies the following parameters can an adhesion strength of 1 MPa be achieved. 5 S -1 Up to 10 10 S -1 Only metal hydroxides can produce adhesive composites with high adhesion performance.

[0121] Test Example 2

[0122] This test example uses Mg(OH)2 as an example to verify and analyze the amount of metal hydroxide added. Specifically, 0 wt%, 0.1 wt%, 1 wt%, 5 wt%, 15 wt%, 30 wt%, 45 wt%, 60 wt%, 75 wt%, 90 wt%, and 100 wt% of Mg(OH)2 powder were added to the viscous liquid of the STU adhesion precursor to prepare adhesion complex x·wt%Mg(OH)2 / STU. The structural properties of each adhesion complex x·wt%Mg(OH)2 / STU (x=0, 0.1, 1, 5, 15, 30, 45, 60, 75, 90, and 100) were then tested.

[0123] 2.1 Characterization of mechanical properties before curing

[0124] The adhesion composite 15wt%Mg(OH)2 / STU was subjected to strain scanning tests using a rheometer to monitor the changes in its storage modulus (G') and loss modulus (G'') with strain. The results are as follows: Figure 2 As shown.

[0125] according to Figure 2 It can be seen that the adhesion composite 15wt%Mg(OH)2 / STU before curing exhibits a loss modulus (G'') greater than the storage modulus (G'), and is characterized as a viscous fluid with good flowability and injectability.

[0126] 2.2 Injectability Testing

[0127] Each adhesion complex (x·wt%Mg(OH)2 / STU) was loaded into a standard syringe, and its injection force was tested using a texture analyzer or a universal testing machine. The results were as follows: Figure 3 As shown.

[0128] according to Figure 3 It can be seen that as the amount of Mg(OH)2 added increases, the initial injection force gradually increases, but it is still within a suitable injection force range (e.g., less than 5N), thus indicating that the adhesion compound of the present invention has good injectability.

[0129] 2.3 Characterization of mechanical properties after curing

[0130] After the adhesion composite 15wt% Mg(OH)2 / STU was immersed in an underwater environment and cured for 24 hours, strain scanning tests were performed using a rheometer. The results were as follows: Figure 4 As shown.

[0131] according to Figure 4 It can be seen that the cured adhesion composite 15wt%Mg(OH)2 / STU exhibits a storage modulus (G') greater than the loss modulus (G''), indicating that the fluid dynamic adhesion composite 15wt%Mg(OH)2 / STU can be transformed into an elastic solid and successfully cured.

[0132] 2.4 Morphological characterization before and after curing

[0133] After the adhesion composite 15wt% Mg(OH)2 / STU was immersed in an underwater environment for 24 hours and cured, it was freeze-dried and sputter-coated with gold. The microstructure was then observed using a scanning electron microscope. The results were as follows: Figure 5 As shown.

[0134] according to Figure 5 It can be seen that, compared with the porous structure of the STU adhesion precursor, the network structure of the adhesion complex 15wt%Mg(OH)2 / STU with added Mg(OH)2 becomes denser, indicating that the addition of Mg(OH)2 effectively drives the directional transformation of the porous structure of the STU adhesion precursor to a denser, higher-order structure.

[0135] 2.5 Characterization of secondary structure before and after curing

[0136] After the adhesion complex (15 wt% Mg(OH)2 / STU) was immersed in an underwater environment for 24 hours to cure, the secondary structure content of silk fibroin was determined by circular dichroism (CD) chromatography. The results were as follows: Figure 6 As shown.

[0137] according to Figure 6 It can be seen that, compared with the STU adhesion precursor, the adhesion complex with added Mg(OH)2 (15wt%Mg(OH)2 / STU) has a significantly increased β-sheet content, confirming that the introduction of Mg(OH)2 effectively drives the directional transformation of protein secondary structure and provides a basis for enhanced cohesion.

[0138] 2.6 Adhesion strength test of adhesion composites with different metal hydroxide addition amounts (x·wt%Mg(OH)2 / STU)

[0139] According to the ASTM F2255 standard method for testing lap shear strength, each adhesive compound was applied between two stainless steel sheets (bonding area 2.5 cm²). After curing underwater for 24 hours, the lap shear strength was tested using a universal testing machine. The results were as follows: Figure 7 As shown.

[0140] according to Figure 7 It can be seen that the underwater steel-to-steel bonding strength of the STU adhesion precursor is less than 0.1 MPa, while the underwater steel-to-steel bonding strength of the adhesion composite with added Mg(OH)2 increases significantly with increasing concentration.

[0141] 2.7 Underwater durability test

[0142] After the adhesion composite 15wt% Mg(OH)2 / STU was immersed in an underwater environment and cured for 24 hours, it was then immersed in an underwater environment for extended periods (1 day, 1 month, 6 months, and 1 year). The remaining lap shear strength was tested at different time points, and the results were as follows: Figure 8 As shown.

[0143] according to Figure 8 It is evident that the adhesion strength of the 15wt%Mg(OH)2 / STU adhesion complex remained almost unchanged after long-term immersion, indicating that the adhesion complex prepared in this application possesses excellent long-term stability.

[0144] 2.8 Temperature stability test

[0145] After the adhesion composite 15wt% Mg(OH)2 / STU was immersed in an underwater environment and cured for 24 hours, its lap shear strength was tested after being kept at different temperatures (-196℃, 0℃, 25℃, 100℃) for 24 hours and then restored to room temperature. The results were as follows: Figure 9 As shown.

[0146] according to Figure 9 It can be seen that the adhesion strength of the 15wt%Mg(OH)2 / STU adhesion composite remains almost unchanged after extreme temperature treatment, indicating that the adhesion performance of the adhesion composite prepared in this invention has excellent stability over a wide temperature range.

[0147] Test Example 3

[0148] To verify the universality of the adhesion complex based on metal hydroxides for optimizing adhesion properties, this application also provides Examples 9-11.

[0149] Example 9

[0150] This example provides an adhesion composite material of 15wt% Mg(OH)2 / GTU with optimized adhesion properties based on metal hydroxides. The only difference between this composite and Example 1 is:

[0151] GTU was prepared by replacing silk fibroin with gelatin during the STU preparation process in Example 1. Adding magnesium hydroxide (Mg(OH)2) at 15 wt% of its mass to the viscous liquid of the GTU adhesion precursor yielded the adhesion complex 15 wt% Mg(OH)2 / GTU.

[0152] Example 10

[0153] This example provides an adhesion composite 15wt%Mg(OH)2 / CTU with optimized adhesion properties based on metal hydroxides, which differs from Example 1 only in that:

[0154] CTU was prepared by replacing silk fibroin with collagen during the STU preparation process in Example 1. Adding magnesium hydroxide (Mg(OH)2) at 15 wt% of its mass to the viscous liquid of the CTU adhesion precursor yields the adhesion complex 15 wt% Mg(OH)2 / CTU.

[0155] Example 11

[0156] This example provides an adhesion composite material of 15wt% Mg(OH)2 / WTU with optimized adhesion properties based on metal hydroxides. The only difference between this composite and Example 1 is:

[0157] WTU was prepared by replacing silk fibroin with gluten protein in the STU preparation process of Example 1. Magnesium hydroxide (Mg(OH)2) at 15 wt% of its mass was added to the viscous liquid of the WTU adhesion precursor to obtain the adhesion complex 15 wt% Mg(OH)2 / WTU.

[0158] according to Figure 10 It is evident that the adhesion complexes 15wt%Mg(OH)2 / GTU, 15wt%Mg(OH)2 / CTU, and 15wt%Mg(OH)2 / WTU can also achieve a significant enhancement of adhesion performance, with adhesion strengths all far exceeding 1MPa. This enhancement effect is similar to that of the STU adhesion precursor prepared using silk fibroin, indicating that the protein in the adhesion precursor of this application is not limited to silk fibroin, but can also be gelatin, collagen, keratin, soy textured protein, gluten, and fibrin, etc.

[0159] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0160] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. An adhesive composite based on metal hydroxide to optimize adhesion properties, characterized in that, It contains an adhesion precursor and a metal hydroxide in a mass ratio of 100:1 to 100; The adhesion precursor is composed of a protein-polyphenol composite hydrogel and a hydrogen bond-breaking small molecule compound, and the adhesion precursor can undergo network reconstruction involving β-sheet formation in an aqueous phase containing the metal hydroxide. The metal hydroxide has the following characteristics: (a) Hydration enthalpy values ​​from -1000 kJ / mol to -4000 kJ / mol; (b) Dissociation constants from 6 pKa to 13.5 pKa; and (c)10 5 S -1 Up to 10 10 S -1 The water exchange rate.

2. The adhesion compound according to claim 1, characterized in that, The metal hydroxide has the following characteristics: (a) Hydration enthalpy values ​​ranging from -1309 kJ / mol to -2099 kJ / mol; (b) Dissociation constants from 8 pKa to 13.4 pKa; and (c)9×10 5 S -1 Up to 5.7×10 9 S -1 The water exchange rate.

3. The adhesion compound according to claim 1 or 2, characterized in that, The metal hydroxide is selected from hydroxides containing magnesium, calcium, strontium, barium, manganese, cobalt, copper, and zinc.

4. The adhesion compound according to claim 1 or 2, characterized in that, The protein component in the protein-polyphenol composite hydrogel is selected from at least one of silk fibroin, gelatin, collagen, keratin, soy textured protein, gluten, and fibroin. And / or, the polyphenol component in the protein-polyphenol composite hydrogel is selected from at least one of tannic acid, dopamine, caffeic acid, tea polyphenols, and anthocyanins.

5. The adhesion compound according to claim 4, characterized in that, The hydrogen bond-breaking small molecule compound is selected from at least one of urea, guanidine hydrochloride, and thiourea.

6. The adhesion compound according to claim 1 or 2, characterized in that, The mass ratio of the adhesion precursor to the metal hydroxide is 100:15~100.

7. The adhesion complex according to claim 1 or 2, characterized in that, The adhesion precursor comprises a solution and a powder.

8. The adhesion compound according to claim 1 or 2, characterized in that, After the adhesive compound has fully cured, the lap shear strength, as measured by ASTM F2255-24, is greater than 1 MPa.

9. A method for preparing an adhesive composite with optimized adhesion properties based on metal hydroxide according to any one of claims 1 to 8, characterized in that, Include: An adhesion precursor is prepared by mixing a protein-polyphenol composite hydrogel with a hydrogen bond-breaking small molecule compound; and the adhesion precursor is mixed with a metal hydroxide to form an adhesion complex.

10. The adhesion complex based on metal hydroxide with optimized adhesion properties according to any one of claims 1 to 8 is used in biomedical bonding, fixation and repair of bone tissue, bonding and repair of underwater structures, marine engineering, aerospace component assembly, automobile manufacturing, and electronic component packaging.

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