Photoresponsive self-healing materials, methods of making and using the same

Abstract

The application provides a light response self-repairing material and a preparation method and application thereof, and relates to the technical field of self-repairing materials.The light response self-repairing material takes a photosensitive polymer as a matrix, modified nanosilica and a plant extraction adhesive are wrapped in the self-repairing material, under ultraviolet irradiation, the photosensitive polymer is softened and the modified nanosilica and the plant extraction adhesive are released, the plant extraction adhesive expands when meeting water, and a silica gel network is formed by combining the modified nanosilica, so that cracks are rapidly filled; meanwhile, the toughening fibers in the silica gel network can effectively improve the strength of the repaired crack gap. In addition, it has been verified that the light response self-repairing material can achieve good repair effect in low-temperature or high-salinity water, and can be widely applied to the preparation process of river revetment surface coating.

Description

Technical Field

[0001] This invention relates to the field of self-healing materials technology, and in particular to a photoresponsive self-healing material, its preparation method, and its application. Background Technology

[0002] Riverbank protection is a crucial measure to ensure riverbank stability. By reinforcing riverbank slopes, it effectively prevents soil erosion and shoreline collapse, avoiding damage to farmland and buildings. It can regulate water flow patterns, reduce the risk of flood erosion, and maintain the safety of river channels during floods. Simultaneously, ecological riverbank protection takes into account both vegetation restoration and habitat protection, promoting soil and water conservation and ecological balance, and playing a vital role in disaster prevention and mitigation, protecting the lives and property of riverside residents, and ensuring sustainable development.

[0003] Existing revetments are mainly classified into rigid (concrete, masonry, etc.), flexible (gabions, eco-bags, etc.), and ecological (vegetated slope protection, fish nest bricks, etc.) structures. Rigid structures have strong erosion resistance, ecological structures combine protection and natural restoration, and flexible structures combine stability and permeability, adapting to different river channel needs. However, the self-repair efficiency of existing revetments is limited, especially in low-temperature or high-salinity waters where the repair effect is significantly reduced, making it difficult to meet application requirements.

[0004] Therefore, it is both necessary and urgent to research and develop a photoresponsive self-healing material that can overcome environmental temperature and salinity limitations and is suitable for various aquatic environments for preparing surface coatings for riverbank protection.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The primary objective of this invention is to provide a photoresponsive self-healing material that has the advantages of being resistant to low-temperature and high-salinity environments, and can effectively fill cracks and fissures in various types of revetments, thereby achieving self-repair of the cracks in the revetments.

[0007] The second objective of this invention is to provide a method for preparing a photoresponsive self-healing material.

[0008] A third objective of this invention is to provide an application of a photoresponsive self-healing material.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: The present invention provides a photoresponsive self-healing material, wherein the raw materials comprising the photoresponsive self-healing material, by weight, are: The composition includes 30-60 parts of photosensitive polymer, 15-25 parts of modified nano-silica, 15-30 parts of plant-extracted adhesive, 5-15 parts of toughening fiber, and 5-15 parts of photoinitiator.

[0010] Furthermore, by weight, the constituent raw materials of the photoresponsive self-healing material include: The composition includes 40 parts of photosensitive polymer, 20 parts of modified nano-silica, 20 parts of plant-extracted adhesive, 10 parts of toughening fiber, and 10 parts of photoinitiator.

[0011] Furthermore, the photosensitive polymer includes at least one of polyvinyl butyral (PVB), polycaprolactone-based polyurethane (PCL-PU), polybutylene succinate (PBS), and polycaprolactone-PCL, preferably polycaprolactone-PCL. Furthermore, the toughening fiber includes at least one of glass fiber, basalt fiber, aramid fiber and carbon fiber, preferably carbon fiber; Furthermore, the photoinitiator includes at least one of methyl benzoylformate, 2-isopropylthioxanthone, macromolecular photoinitiator and benzophenone, preferably benzophenone.

[0012] Furthermore, the modified nano-silica is obtained by improving nano-silica using a silane coupling agent.

[0013] Furthermore, the particle size of the nano-silica is 20~50nm.

[0014] Furthermore, the photoresponsive self-healing material also includes a plasticizer, which includes at least one of propylene glycol, sorbitol, ethylene glycol, and glycerin; This invention provides a method for preparing a photoresponsive self-healing material, the method comprising: S1: Dissolve the plant adhesive in deionized water to activate it, and obtain an activated plant adhesive solution; S2: After melting the photosensitive polymer, modified nano-silica, activated plant adhesive solution, toughening fiber and photoinitiator are added in sequence and stirred for homogenization treatment. Vacuum degassing is then performed to obtain a photoresponsive self-healing material.

[0015] Furthermore, the temperature for melting and homogenizing the photosensitive polymer in step S2 is 120℃~180℃.

[0016] Furthermore, in step S2, vacuum degassing is carried out in a vacuum reactor with a vacuum degree of -0.08 to -0.12 MPa and a time of 15 to 30 min.

[0017] The application of the photoresponsive self-healing material provided by this invention in the preparation of surface coatings for riverbank protection.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The photoresponsive self-healing material provided by this invention mainly consists of a photosensitive polymer, modified nano-silica, plant-extracted adhesive, toughening fibers, and a photoinitiator. The photoresponsive self-healing material uses a photosensitive polymer as a matrix, encapsulating modified nano-silica and the plant-extracted adhesive within the repair material. Under ultraviolet irradiation, the photosensitive polymer softens and releases the modified nano-silica and the plant-extracted adhesive. The plant-extracted adhesive swells upon contact with water, combining with the modified nano-silica to form a silicone network that rapidly fills cracks. Simultaneously, the toughening fibers within the silicone network effectively improve the strength of the repaired gap.

[0019] The present invention provides a method for preparing a photoresponsive self-healing material. The method first involves dissolving a plant-based adhesive in deionized water to activate it, obtaining an activated plant-based adhesive solution. Then, a photosensitive polymer is melted, and modified nano-silica, the activated plant-based adhesive solution, toughening fibers, and a photoinitiator are added sequentially, followed by stirring and homogenization treatment. Vacuum degassing is then performed to obtain the photoresponsive self-healing material. The above-mentioned method for preparing the photoresponsive self-healing material has the technical advantages of simple processing and ease of operation.

[0020] The photoresponsive self-healing material provided by this invention has the technical advantage of being able to overcome environmental temperature and salinity limitations and be applicable to a variety of aquatic environments, and can be widely used in the preparation process of surface coatings for riverbank protection. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A flowchart illustrating the photoresponsive self-healing mechanism of the photoresponsive self-healing material provided by this invention. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] According to one aspect of the present invention, a photoresponsive self-healing material, wherein the raw materials comprising the photoresponsive self-healing material, by weight parts, are: The composition includes 30-60 parts of photosensitive polymer, 15-25 parts of modified nano-silica, 15-30 parts of plant-extracted adhesive, 5-15 parts of toughening fiber, and 5-15 parts of photoinitiator.

[0025] The photoresponsive self-healing material provided by this invention is mainly composed of photosensitive polymer, modified nano-silica, plant-extracted adhesive, toughening fiber and photoinitiator.

[0026] Figure 1 A flowchart illustrating the photoresponsive self-healing mechanism of the photoresponsive self-healing material provided by this invention.

[0027] Depend on Figure 1 As can be seen, the photoresponsive self-healing material of this invention uses a photosensitive polymer as a matrix, encapsulating modified nano-silica and plant-extracted adhesive within the repair material. Under ultraviolet irradiation, the photosensitive polymer softens and releases the modified nano-silica and plant-extracted adhesive. The plant-extracted adhesive swells upon contact with water, combining with the modified nano-silica to form a silicone network that rapidly fills cracks. Simultaneously, the toughening fibers within the silicone network effectively enhance the strength of the repaired gap. Furthermore, it has been verified that the photoresponsive self-healing material of this application can achieve good repair results in low-temperature or high-salinity water environments.

[0028] In a preferred embodiment of the present invention, the raw materials comprising the photoresponsive self-healing material, by weight, include: The composition includes 40 parts of photosensitive polymer, 20 parts of modified nano-silica, 20 parts of plant-extracted adhesive, 10 parts of toughening fiber, and 10 parts of photoinitiator.

[0029] In a preferred embodiment of the present invention, the photosensitive polymer includes at least one of polyvinyl butyral (PVB), polycaprolactone-based polyurethane (PCL-PU), polybutylene succinate (PBS), and polycaprolactone-PCL, preferably polycaprolactone-PCL. As a preferred embodiment, polycaprolactone (PCL), as a preferred photosensitive polymer, has superior technical advantages in low-temperature / high-salinity water remediation performance. For example: Low-temperature flexibility and freeze-crack resistance: PCL's low glass transition temperature (-60℃) and high molecular chain mobility ensure that it can still soften and flow through UV triggering at low temperatures, while PLA / PBS has difficulty releasing repair components at low temperatures due to the rigidity of its molecular chains. For details, please refer to Table 1 below.

[0030] Table 1:

[0031] Hydrolysis resistance and salt stability: After soaking in 3% NaCl for 90 days, the PCL-based material retained more than 85% of the repair strength, while the PLA-based material retained only 55% (due to accelerated hydrolysis of ester bonds). See Table 2 below for details.

[0032] Table 2:

[0033] In a preferred embodiment of the present invention, the toughening fiber includes at least one of glass fiber, basalt fiber, aramid fiber and carbon fiber, preferably carbon fiber; In a preferred embodiment of the present invention, the photoinitiator includes at least one of methyl benzoylformate, 2-isopropylthioxanthone, macromolecular photoinitiator and benzophenone, preferably benzophenone.

[0034] In a preferred embodiment of the present invention, the modified nano-silica is obtained by improving nano-silica using a silane coupling agent.

[0035] As a preferred embodiment, modifying nano-silica with a silane coupling agent can effectively improve the compatibility between nano-silica and photosensitive polymers. Specifically, after modification with a silane coupling agent (KH-550), nano-SiO2 is coated with hydrophobic alkyl long chains, effectively blocking Cl⁻ corrosion, and exhibiting dispersion stability >90% in 3% NaCl. Furthermore, the quaternary ammonium groups (-N⁺(CH₃)₃) in the plant adhesive neutralize the salt ion charge, reducing the damage of Na⁺ to the hydrophilic groups, resulting in a swelling rate decrease of <10% (unmodified >40%). Therefore, the photoresponsive self-healing material of this application exhibits excellent high-salt resistance.

[0036] In the preferred embodiment described above, the particle size of the nano-silica is 20~50nm.

[0037] Preferably, the preparation method of the plant extract adhesive is as follows: Step 1: Raw Material Screening and Pretreatment: First, konjac glucomannan and flaxseed gum (mass ratio 7:3) were selected as the core raw materials, taking into account both high water absorption and salt resistance. The raw materials were crushed and passed through an 80-mesh sieve (particle size ≤180μm), then immersed in a 70% ethanol solution (material-to-liquid ratio 1:10) for 30 minutes to degrease and inactivate enzymes. Finally, they were rinsed with deionized water until neutral to avoid residues affecting subsequent polymer compatibility.

[0038] Step 2: Targeted Extraction and Purification: The pretreated raw materials were added to 95℃ hot water (material-to-liquid ratio 1:15). Konjac gum was protected with pH 6.5 phosphate buffer to protect the acetyl groups, and flaxseed gum was extracted with pH 8.0 weakly alkaline water to increase yield. The mixture was extracted at a constant temperature for 2 hours to dissolve the polysaccharide. After centrifugation (4000 rpm, 20 min) to remove residue, 3 times the volume of 95% ethanol was added to the supernatant, and the mixture was allowed to stand at 4℃ for 12 hours to precipitate the polysaccharides. The precipitate was collected and vacuum dried at 50℃ (-0.08 MPa) until the water content was ≤5%, yielding purified gum powder.

[0039] Step 3: Chemical modification to enhance performance: Hydroxypropylation modification: The rubber powder and propylene oxide (1:0.4 mass ratio) were reacted at 40℃ under the catalysis of 0.1mol / L NaOH for 4 hours. After terminating with glacial acetic acid, the mixture was washed with alcohol and dried to introduce hydroxypropyl groups to shield against salt ion interference. Step 4: Preparation of Activation Solution: Dissolve the modified adhesive powder in deionized water at a concentration of 20%, stir at 60°C for 1 hour until completely hydrated, forming a homogeneous viscous liquid. Add 0.5% potassium sorbate as a preservative to inhibit the growth of microorganisms in the aquatic environment. The resulting solution is the "plant adhesive solution" described in this invention, which can be directly used for blending with photoresponsive materials.

[0040] It should be noted that the hydroxypropylated modified plant adhesive of this application can form "hydrophobic-hydrophilic microregions". The hydrophilic region binds water molecules through hydrogen bonds to inhibit ice crystal growth, while the hydrophobic region (hydroxypropyl long chain) blocks the expansion of ice nuclei, so that the material still maintains >80% swelling capacity at -20℃. Therefore, the photoresponsive self-healing material of this application has excellent low-temperature resistance.

[0041] In a preferred embodiment of the present invention, the photoresponsive self-healing material further includes a plasticizer, wherein the plasticizer includes at least one selected from propylene glycol, sorbitol, ethylene glycol, and glycerin; As a preferred embodiment, the plasticizer can reduce the glass transition temperature of the system to -30°C. At the same time, after the photopolymer (PCL) matrix is ​​embedded with the plasticizer, the melt viscosity can be significantly reduced, ensuring that the repair agent can quickly flow and fill the crack after UV triggering at low temperature.

[0042] According to one aspect of the present invention, a method for preparing a photoresponsive self-healing material, the method comprising: S1: Dissolve the plant adhesive in deionized water to activate it, and obtain an activated plant adhesive solution; S2: After melting the photosensitive polymer, modified nano-silica, activated plant adhesive solution, toughening fiber and photoinitiator are added in sequence and stirred for homogenization treatment. Vacuum degassing is then performed to obtain a photoresponsive self-healing material.

[0043] The present invention provides a method for preparing a photoresponsive self-healing material. The method first involves dissolving a plant-based adhesive in deionized water to activate it, obtaining an activated plant-based adhesive solution. Then, a photosensitive polymer is melted, and modified nano-silica, the activated plant-based adhesive solution, toughening fibers, and a photoinitiator are added sequentially, followed by stirring and homogenization treatment. Vacuum degassing is then performed to obtain the photoresponsive self-healing material. The above-mentioned method for preparing the photoresponsive self-healing material has the technical advantages of simple processing and ease of operation.

[0044] In a preferred embodiment of the present invention, the temperature for melting and homogenizing the photosensitive polymer in step S2 is 120°C to 180°C. In a preferred embodiment of the present invention, the vacuum degassing in step S2 is carried out in a vacuum reactor, the vacuum degree of the vacuum degassing is -0.08 to -0.12 MPa, and the time is 15 to 30 min.

[0045] According to one aspect of the present invention, the photoresponsive self-healing material is used in the preparation of surface coatings for riverbank protection.

[0046] The photoresponsive self-healing material provided by this invention has the technical advantage of being able to overcome environmental temperature and salinity limitations and be applicable to a variety of aquatic environments, and can be widely used in the preparation process of surface coatings for riverbank protection.

[0047] The technical solution of the present invention will be further described below with reference to the embodiments.

[0048] Example 1 A photoresponsive self-healing material, comprising, by weight parts, the following raw materials: 40 parts of photosensitive polymer, 20 parts of modified nano silica, 20 parts of plant-extracted adhesive, 10 parts of toughening fiber, 10 parts of photoinitiator, and 5 parts of plasticizer.

[0049] The preparation method of the photoresponsive self-healing material includes: (1) Pretreatment and dispersion: Nano silica modification: Nano silica was placed in an ethanol solution of silane coupling agent (KH-550) and ultrasonically treated for 30 minutes to improve its compatibility with the polymer matrix; During the modification process, the mass ratio of nano-silica to silane coupling agent is 1:0.1.

[0050] Plant-based adhesive activation: The plant-based adhesive is dissolved in deionized water and stirred at 60°C until completely dissolved to obtain an activated solution; the concentration of the plant-based adhesive in the activated solution is 20%. Carbon fiber surface treatment: The carbon fiber surface is oxidized with nitric acid to enhance its interfacial bonding with the matrix material. The specific method is as follows: A. Pretreatment: The carbon fiber is cut into short fibers of 0.5-1 mm and the surface epoxy coating is removed by Soxhlet extraction with acetone for 48 hours (residual amount <0.3%).

[0051] B. Oxidation reaction: Add 50 wt% nitric acid solution (analytical grade) to a polytetrafluoroethylene reactor and preheat to 70°C; add carbon fiber (loading amount 8 g / L) and mechanically stir (200 rpm) to maintain suspension; react at a constant temperature for 60 minutes, and use a condenser to reflux to prevent acid mist from escaping.

[0052] C. Post-treatment: Immediately after the reaction is completed, quench with ice water to terminate the oxidation; wash with deionized water until neutral (pH=6.5-7.0, conductivity <5 μS / cm), then neutralize the residual acid with 0.1M NaHCO3 solution; vacuum dry at 80℃ for 2 hours, and store in a sealed container (to avoid functional group decay).

[0053] (2) Mixing and blending Melt blending: Heat PCL particles to 160°C to melt, then add modified nano-silica, activated plant adhesive solution, carbon fiber and benzophenone in sequence, and keep the mixture at a constant temperature and stir (160°C, 200 rpm, 30 minutes). Plasticizer addition: Add glycerin and continue stirring for 10 minutes to ensure homogenization of the system; Vacuum degassing: Transfer the mixture to a vacuum reactor and evacuate to -0.1 MPa to remove bubbles for 20 minutes.

[0054] (3) Molding and curing Mold forming: The degassed melt is injected into a pre-made mold (length, width, height: 500mm, 500mm, 10mm) and cooled to room temperature (20~23℃) for solidification; UV pre-activation: The molding material is subjected to short-term ultraviolet irradiation (wavelength 365nm, intensity 50mW / cm², time 5 minutes) to initiate partial cross-linking of the photoinitiator and initially form a photoresponsive network; Post-curing treatment: Place in a 50℃ oven and let stand for 24 hours to eliminate internal stress and stabilize the material structure.

[0055] Example 2 A photoresponsive self-healing material, comprising, by weight parts, the following raw materials: 30 parts of photosensitive polymer, 15 parts of modified nano silica, 15 parts of plant-extracted adhesive, 5 parts of toughening fiber, 5 parts of photoinitiator, and 5 parts of plasticizer.

[0056] The preparation method of the photoresponsive self-healing material is the same as in Example 1.

[0057] Example 3 A photoresponsive self-healing material, comprising, by weight parts, the following raw materials: 60 parts of photosensitive polymer, 25 parts of modified nano-silica, 30 parts of plant-extracted adhesive, 15 parts of toughening fiber, 15 parts of photoinitiator, and 5 parts of plasticizer.

[0058] The preparation method of the photoresponsive self-healing material is the same as in Example 1.

[0059] Comparative Example 1 A photoresponsive self-healing material, comprising, by weight parts, the following raw materials: 40 parts of photosensitive polymer, 20 parts of modified nano-silica, 10 parts of toughening fiber, 10 parts of photoinitiator, and 5 parts of plasticizer.

[0060] The preparation method of the photoresponsive self-healing material is the same as in Example 1.

[0061] This comparative photoresponsive self-healing material is identical to Example 1 except that it does not contain plant-derived adhesive.

[0062] Comparative Example 2 A photoresponsive self-healing material, comprising, by weight parts, the following raw materials: 40 parts of photosensitive polymer, 20 parts of plant-derived adhesive, 10 parts of toughening fiber, 10 parts of photoinitiator, and 5 parts of plasticizer.

[0063] The preparation method of the photoresponsive self-healing material is the same as in Example 1.

[0064] This comparative photoresponsive self-healing material is identical to Example 1 except that it does not contain modified nano-silica.

[0065] Comparative Example 3 This comparative example is the same as Example 1, except that "modified nano silica" is replaced with unmodified nano silica.

[0066] Experimental Example 1 (a) Repair efficiency test: (1) Crack repair test ① Substrate selection Concrete slab (simulating rigid revetment): C30 concrete, dimensions 100mm×100mm×20mm, crack located in the center; Geotextile-gravel composite layer (simulating flexible revetment): three layers of needle-punched geotextile sandwiched with gravel (15mm thick), with cracks penetrating the surface layer.

[0067] ② Crack parameters are shown in Table 3.

[0068] Table 3:

[0069] ③ Test steps: Substrate pretreatment: The concrete substrate is soaked in water for 24 hours (simulating a water-bearing revetment), and the geotextile substrate is sprayed with water to moisten it; Material load: Group 1 (Pre-fabricated patch covering in Example 1): The 20mm × 20mm × 1.5mm repair patch prepared in Example 1 was pressed tightly to cover the crack; Group 2 (Pre-fabricated patch covering in Example 2): The 20mm×20mm×1.5mm repair patch prepared in Example 2 was pressed tightly to cover the crack; Group 3 (Pre-fabricated patch covering in Example 3): The 20mm×20mm×1.5mm repair patch prepared in Example 3 was pressed tightly to cover the crack; Group 4 (comparative Example 1 prefabricated sheet coverage): The 20mm×20mm×1.5mm repair sheet prepared in Comparative Example 1 was tightly pressed to cover the crack; Group 5 (comparative Example 2 prefabricated sheet coverage): The 20mm×20mm×1.5mm repair sheet prepared in Comparative Example 2 was tightly pressed to cover the crack; Group 6 (comparative Example 3 prefabricated sheet coverage): The 20mm×20mm×1.5mm repair sheet prepared in Comparative Example 3 was tightly pressed to cover the crack; Group 7 (Hot Melt Coating): 160℃ melt coating for filling gaps (thickness controlled at 1.5mm); UV repair: Irradiate vertically with a 365nm UV lamp (200W / m²) for 10 minutes at a distance of 10cm; Effect evaluation: Crack closure rate: Crack volume change scanned by laser profilometer (closure rate = (V0-V1) / V0×100%).

[0070] The experimental results are shown in Tables 4 and 5: Table 4:

[0071] Table 5:

[0072] (2) Mechanical performance testing: The detection method is as follows: Three-point bending test (ISO 178): Repaired concrete beam (100mm×20mm×20mm) with a span of 80mm and a loading rate of 2mm / min.

[0073] Compression test (ISO 604): Repair layer cylindrical sample (Φ20mm×10mm), rate 1mm / min.

[0074] Control group: unrepaired cracked substrate; The mechanical performance test results are shown in Table 6.

[0075] Table 6:

[0076] Strength recovery rate = (strength after repair / strength of intact substrate) × 100%.

[0077] (3) Environmental adaptability verification: The specific testing methods are as follows: Low-temperature repair (-20℃): Substrate pre-cooled for 12 hours → Scraping repair → UV irradiation (as before) → Measure crack filling rate.

[0078] High-salt environment (5% NaCl): Immerse the restoration for 30 days → Measure the compressive strength retention rate.

[0079] Water flow erosion (ASTM D7173): Water flow velocity 3 m / s, record the time of repair layer peeling.

[0080] The results of the environmental adaptability test are shown in Table 7.

[0081] Table 7:

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoresponsive self-healing material, characterized in that, The raw materials comprising the photoresponsive self-healing material, by weight, include: 30-60 parts of photosensitive polymer, 15-25 parts of modified nano-silica, 15-30 parts of plant-extracted adhesive, 5-15 parts of toughening fiber and 5-15 parts of photoinitiator; The modified nano-silica is obtained by improving nano-silica using a silane coupling agent; The photosensitive polymer includes at least one of polyvinyl butyral, polycaprolactone-based polyurethane, polybutylene succinate, and polycaprolactone. The preparation method of the plant extract adhesive is as follows: S1 Raw Material Screening and Pretreatment: Konjac glucomannan and flaxseed gum were mixed at a mass ratio of 7:3, pulverized, and passed through an 80-mesh sieve to obtain the raw material. Subsequently, the raw material was soaked in a 70% ethanol solution at a material-to-liquid ratio of 1:10 for 30 minutes to defatt and inactivate enzymes. Then, it was rinsed with deionized water until neutral to obtain the pretreated raw material. S2 directional extraction and purification: The pretreated raw materials were added to 95℃ hot water at a material-to-liquid ratio of 1:

15. Konjac gum was protected with pH 6.5 phosphate buffer, and flaxseed gum was improved with pH 8.0 weak alkaline water. The mixture was extracted at a constant temperature for 2 hours to fully dissolve the polysaccharide gum. Then, it was centrifuged at 4000 rpm for 20 minutes to remove the residue and collect the supernatant. Three volumes of 95% ethanol were added to the supernatant, and the mixture was allowed to stand at 4℃ for 12 hours to precipitate the polysaccharide. The precipitate was then collected and vacuum dried at 50℃ and -0.08 MPa until the water content was ≤5% to obtain purified gum powder. S3 chemical modification enhances performance: The rubber powder was reacted with propylene oxide at a mass ratio of 1:0.4 at 40℃ under the catalysis of 0.1mol / L NaOH for 4 hours. After the reaction was terminated with glacial acetic acid, the mixture was washed with alcohol and dried to obtain the modified rubber powder. Preparation of S4 activation solution: Dissolve the modified adhesive powder at a concentration of 20% in deionized water, stir at 60°C for 1 hour until fully hydrated to form a homogeneous viscous liquid; then add 0.5% potassium sorbate as a preservative to inhibit the growth of microorganisms in the water. The resulting solution is a plant adhesive solution.

2. The photoresponsive self-healing material according to claim 1, characterized in that, The raw materials comprising the photoresponsive self-healing material, by weight, include: The composition includes 40 parts of photosensitive polymer, 20 parts of modified nano-silica, 20 parts of plant-extracted adhesive, 10 parts of toughening fiber, and 10 parts of photoinitiator.

3. The photoresponsive self-healing material according to claim 1 or 2, characterized in that, The photosensitive polymer is polycaprolactone; And / or, the toughening fiber includes at least one of glass fiber, basalt fiber, aramid fiber and carbon fiber; And / or, the photoinitiator includes at least one of methyl benzoylformate, 2-isopropylthioxanthrone, macromolecular photoinitiator, and benzophenone.

4. The photoresponsive self-healing material according to claim 1, characterized in that, The particle size of the nano-silica is 20~50nm.

5. The photoresponsive self-healing material according to claim 1, characterized in that, The photoresponsive self-healing material also includes a plasticizer; The plasticizer includes at least one of epoxidized soybean oil, propylene glycol, sorbitol, ethylene glycol, and glycerin.

6. A method for preparing a photoresponsive self-healing material according to any one of claims 1 to 5, characterized in that, The preparation method includes: S1: Dissolve the plant adhesive in deionized water to activate it, and obtain an activated plant adhesive solution; S2: After melting the photosensitive polymer, modified nano-silica, activated plant adhesive solution, toughening fiber and photoinitiator are added in sequence and stirred for homogenization treatment. Vacuum degassing is then performed to obtain a photoresponsive self-healing material.

7. The method for preparing the photoresponsive self-healing material according to claim 6, characterized in that, In step S2, the temperature for melting and homogenizing the photosensitive polymer is 120℃~180℃.

8. The method for preparing the photoresponsive self-healing material according to claim 6, characterized in that, In step S2, vacuum degassing is carried out in a vacuum reactor with a vacuum degree of -0.08 to -0.12 MPa and a time of 15 to 30 minutes.

9. The application of the photoresponsive self-healing material according to any one of claims 1 to 5 in the preparation of surface coatings for riverbank protection.

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