Eustaphylospore self-repairing waterproof coiled material and preparation method thereof

Abstract

The invention discloses a true staphylococcus spore self-repairing waterproof coiled material and a preparation method, and relates to the technical field of waterproof coiled material optimization. The plant-based asphalt comprises a plant-based asphalt base material, uniformly dispersed heat shielding microcapsules and a functional filler, the heat-shielding microcapsule comprises an inner core which is a sodium alginate / calcium chloride hydrogel core wrapping eustaphylospore dormant bodies, nutrients and nano calcium oxalate crystal seeds, and an outer core which is a sodium alginate / calcium chloride hydrogel core wrapping eustaphylospore dormant bodies, nutrients and nano calcium oxalate crystal seeds, the middle layer is coated outside the inner core and is a phase change material layer, and the phase change temperature of a phase change material is 60-70 DEG C; the shell is coated outside the middle layer and is a polydopamine interface bonding layer; the functional filler comprises active silica fume, nano titanium dioxide, quartz powder, wood fiber and tire rubber powder; through the heat shielding microcapsule, a microenvironment capable of surviving in high-temperature asphalt processing is created for eustaphylospores, so that a microbial remediation technology is introduced into the asphalt-based waterproof coiled material, and the purposes of excellent self-repairing and biological protection functions of the asphalt-based waterproof coiled material are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproofing membrane optimization, in particular to a true spore self-repairing waterproofing membrane and a preparation method thereof. BACKGROUND

[0002] Waterproofing membrane is a key material for building waterproofing engineering, and its performance is directly related to the durability, safety and service life of the building. Developing bio-based asphalt waterproofing membrane using renewable vegetable oil as raw material has become an important research direction for the green transformation of the industry.

[0003] There have been many studies on the use of microbial-induced mineralization deposition to achieve self-repairing of concrete cracks, which provides a new idea for the intelligentization and long-acting of building materials. However, extending this technology to the field of asphalt-based waterproofing membrane faces a seemingly insurmountable technical barrier recognized by the industry: the production of asphalt membrane requires mixing, coating and molding at high temperatures, and any microbial agent will instantly lose its activity in this harsh environment, resulting in the complete loss of its repair function. This fundamental contradiction makes it futile and unfeasible to introduce living microorganisms into asphalt waterproofing membrane. Therefore, a large number of existing technologies limit microbial self-repairing research to cement-based materials systems that are processed at room temperature.

[0004] To improve the performance of bio-based asphalt membrane, researchers usually use physical blending of functional fillers. For example, adding wood fibers to enhance oil locking and improve weather resistance; mixing in tire rubber powder to improve material flexibility and elasticity; adding mineral fillers to increase system stability and reduce cost. In addition, to solve the problem of mold growth of biomass materials, some schemes also attempt to directly add inorganic antibacterial agents such as nano-zinc oxide. However, these existing methods have significant limitations, such as repair and protection being independent components, physical blending being difficult to achieve functional synergy and efficiency. After crack repair, the repair body itself does not have antibacterial properties and is easily invaded by microorganisms again. For example, the addition of a large amount of fillers often damages the mechanical properties of the matrix. In particular, the introduction of rigid inorganic fillers often sacrifices the flexibility and fatigue life of the material. For example, nano-materials are prone to agglomeration, and the interface compatibility between non-polar asphalt and functional fillers is poor, which can cause system instability and performance defects.

[0005] In summary, there is an urgent need in the field for a new solution that can fundamentally overcome the problem of microorganisms not being used in asphalt high-temperature systems, and solve the problems of functional fragmentation and uneven performance caused by existing physical blending technology, to develop a next-generation intelligent bio-based waterproofing membrane that has efficient self-repairing, long-term biological protection and excellent comprehensive performance. SUMMARY

[0006] The present application aims to provide a true spore self-repairing waterproofing membrane and a preparation method, which creates a microenvironment for the true spore to survive in high-temperature asphalt processing through heat-shielding microcapsules, thereby introducing microbial repair technology into asphalt-based waterproofing membranes to achieve the purposes of excellent self-repairing and biological protection functions.

[0007] In order to achieve the above-mentioned purposes, the present application adopts the following technical means: A true spore self-repairing waterproofing membrane, comprising a plant-based asphalt base material, uniformly dispersed heat-shielding microcapsules, and functional fillers. The heat-shielding microcapsules comprise: a core, which is a sodium alginate / calcium chloride hydrogel core wrapping true spore dormant bodies, nutrients, and nano calcium oxalate seeds; an intermediate layer, which is a phase change material layer wrapped outside the core, and the phase change temperature of the phase change material is 60-70 DEG C; an outer shell, which is a polydopamine interface bonding layer wrapped outside the intermediate layer; The functional fillers include active silica ash, nano titanium dioxide, quartz powder, wood fiber, and tire rubber powder.

[0008] In this way, the microcapsules with a triple protection structure are constructed; The sodium alginate-calcium chloride cross-linked hydrogel core wraps the true spore dormant bodies, nutrients, and nano calcium oxalate seeds, and uses the hydrogel core to provide a humid dormant environment for the spore dormant bodies; Then, the intermediate layer is constructed, and a layer of phase change material microcapsules is wrapped outside the inner hydrogel through in-situ polymerization, thereby forming a heat-shielding layer. When the external asphalt temperature rises suddenly, the phase change material layer absorbs a large amount of heat through solid-liquid phase change, thereby ensuring that the environment temperature of the inner hydrogel core is stable for a long time and remains below the phase change temperature, so as to provide good thermal protection for the spore dormant bodies and avoid the inactivation of the spore dormant bodies during the construction of the waterproofing membrane; Finally, the polydopamine interface outer layer is constructed, which greatly improves the compatibility between the microcapsules and the hydrophobic plant-based asphalt base material by using the adhesion of the polydopamine interface, avoids the massive aggregation of the heat-shielding microcapsules, and enhances the mechanical properties of the membrane.

[0009] Moreover, after the waterproofing membrane is prepared, when a crack occurs and water enters, the water will gradually soften and eventually dissolve the phase change material layer and the outer layer, so as to expose the inner hydrogel spore core. After the exposed spore core meets water, the spores are rapidly activated and start to metabolize. The oxalate ions secreted by the spore metabolism combine with the calcium ions in the matrix, and grow into calcium oxalate crystals with the pre-set nano calcium oxalate seeds as templates, thereby efficiently filling the cracks. This process is faster and more efficient than simply relying on the spontaneous crystallization speed of the spores.

[0010] Moreover, during the metabolism of *Stachys cerevisiae*, a variety of organic acids and antibacterial compounds are naturally produced. These products lower the pH value of the crack repair area and form a natural antibacterial microenvironment, which can effectively inhibit the growth of harmful microorganisms such as white rot fungi and Aspergillus, thus achieving repair as protection.

[0011] Preferably, the phase change material is a eutectic mixture of eicosanoic acid and docosanoic acid, wherein, by weight, the eicosanoic acid comprises 5-11.5 parts, the docosanoic acid comprises 2-4.5 parts, the nano-titanium dioxide has a particle size of 20-50 nm, and the quartz powder has a mesh size of 300 mesh.

[0012] Furthermore, by adjusting the dosage of eicosanoic acid and docosanoic acid, the eutectic phase transition temperature of the phase change material formed by the mixture of eicosanoic acid and docosanoic acid is controlled at 60~70℃, while ensuring the amount and thickness of the intermediate layer of the phase change material. This ensures that the phase change material layer has sufficient thickness and quantity to provide effective thermal shielding, and its specific eutectic composition ensures the stability of the phase transition temperature, thereby avoiding the problem of microbial inactivation during the high-temperature processing of asphalt.

[0013] Meanwhile, for the mixture of eicosanoic acid and docosanoic acid, the two acids are stirred and melted in a molten state, and then the melt is rapidly poured onto a pre-cooled metal tray and rapidly cooled and solidified at room temperature to form a solid eutectic mixture sheet. This rapid cooling process helps to suppress component segregation and form a uniform eutectic structure. Finally, the sheet is broken and ground into powder to obtain phase change material powder for later use.

[0014] Furthermore, the nutrient is glucose, and the particle size of the nano-calcium oxalate seed crystals is 20~100nm.

[0015] Furthermore, by weight, it includes: 100 parts plant-based asphalt, 10-20 parts heat-shielding microcapsules, 3-5 parts active silica fume, 0.5-2 parts nano titanium dioxide, 20-25 parts quartz powder, 3-5 parts wood fiber, and 15-20 parts tire rubber powder.

[0016] In addition, a method for preparing the aforementioned self-healing waterproof membrane based on *Stachys edulis* spores includes the following steps: S1. Preparation of heat-shielding microcapsules; S2. Heat the plant-based bitumen to a molten state, then cool it to 120~135℃; S3. Under stirring conditions, the heat-shielding microcapsules are added to the cooled plant-based asphalt and mixed at low speed until uniform to obtain a mixture. S4. Coat, cover, and cool the mixture to form a roll.

[0017] Preferably, in step S1, the heat-shielding microcapsules are prepared using microfluidic control technology, thereby accurately preparing microcapsules with a three-layer structure of "hydrogel-phase change material-polydopamine", including the following steps: S11. Prepare an aqueous core containing dormant *Stachys edulis* spores, nutrients, nano-calcium oxalate seeds, and sodium alginate; S12. Using a microfluidic device, the aqueous core solution and calcium chloride solution are mixed to form droplets and undergo a cross-linking reaction to form a hydrogel microsphere core; S13. Molten phase change material is wrapped around the core of hydrogel microspheres, and after cooling, a phase change material intermediate layer is formed; S14. A polydopamine outer layer is formed outside the intermediate layer of the phase change material by in-situ polymerization of dopamine under weakly alkaline conditions.

[0018] Furthermore, in step S13, the phase change material is heated to 70~75°C and then encapsulated to form a molten state, thereby constructing a heat shield layer outside the fragile hydrogel microsphere core that can absorb a large amount of heat through solid-liquid phase change, thus protecting the internal spore dormant body from high temperature damage. Step S13 includes: S131. Select eicosanoic acid and docosanoic acid, mix them, and heat them in a water bath at 70~75℃ until they are completely melted into a transparent liquid, which is used as a phase change liquid; S132. The hydrogel microsphere core is dispersed in deionized water containing 1% Tween-80 as the inner phase fluid, and the molten phase change liquid is used as the intermediate phase fluid. The water core-phase change shell composite droplets are formed in a coaxial microfluidic device according to the flow rate ratio of inner phase fluid to intermediate phase fluid of 1:3. The temperature of the entire microfluidic device and receiving cell needs to be maintained at 70-75℃ to ensure that the phase change material remains liquid during the encapsulation process and does not solidify prematurely.

[0019] S133. Collect the composite droplets into a cooling container and cool the composite droplets to room temperature at a rate of 5~10℃ / min to obtain the phase change material intermediate layer.

[0020] During the cooling step, the phase change material shell is uniformly cooled and recrystallized from a liquid state into a solid state, ultimately forming a dense and fully encapsulated "hydrogel core / phase change material solid shell" microsphere.

[0021] Furthermore, step S14 is used to construct a hydrophilic interface layer with super-strong adhesion outside the hydrophobic phase change material shell, so as to greatly improve the compatibility between the microcapsules and the hydrophobic bitumen matrix and prevent phase separation and performance failure. S14 includes: S141. The obtained phase change material intermediate layer is dispersed in a Tris-HCl buffer solution with pH=8.5 to form a dispersion to provide conditions for initiating the spontaneous polymerization of dopamine. Dopamine hydrochloride powder is added to the dispersion according to a mass ratio of 1:5 between dopamine hydrochloride and the phase change material intermediate layer. S142. Place the mixture at room temperature and stir at 200-300 rpm for 12-24 hours. Throughout the process, dopamine monomers dissolved in the solution undergo oxidative self-polymerization under the catalysis of dissolved oxygen, generating polydopamine. Polydopamine molecules preferentially adsorb and deposit on the surface of hydrophobic phase change material microspheres, forming strong covalent and non-covalent bonds with the phase change material surface through their contained groups, thereby forming a uniform and dense polydopamine nanocoating in situ outside the microspheres.

[0022] S143. After the reaction is complete, the intermediate layer of the phase change material is collected by filtration, washed, and then dried at 30°C to obtain heat-shielding microcapsules.

[0023] Thus, in step S14, the room temperature and aqueous phase reaction conditions maximize the protection of the integrity of the internal phase change material layer and the hydrogel core.

[0024] Furthermore, in step S3, under stirring conditions of 120~135℃, the heat-shielding microcapsules, wood fiber, tire rubber powder, active silica fume, nano titanium dioxide and quartz powder are added sequentially, and stirred at a speed of 150-250 rpm for 20-40 minutes until they are evenly mixed.

[0025] In this step, heat-shielding microcapsules are added first. While ensuring that the stirring time allows for uniform dispersion, the stirring and mixing time is controlled to prevent the heat-shielding microcapsules from being exposed to a high-temperature environment in the molten asphalt matrix for an extended period. This controls the high-temperature exposure time of the heat-shielding microcapsules during asphalt processing, ensuring that the intermediate phase change layer of the heat-shielding microcapsules remains in a phase change state throughout the stirring and mixing process. This keeps the temperature of the internal core below the phase change temperature, effectively isolating the high-temperature environment from the internal microbial spores within a limited processing time window by allowing the intermediate phase change material to actively absorb heat and undergo a phase change. This overcomes the problem of spore inactivation caused by high processing temperatures.

[0026] Furthermore, the active silica fume, nano titanium dioxide, and quartz powder are premixed to form a composite filler before being added, and then simultaneously added to the mixing system as a composite filler.

[0027] The waterproof membrane involved in this invention has the following beneficial effects: By using heat-shielded microcapsules, a high survival rate of *Stachys cerevisiae* spores is achieved after high-temperature asphalt processing. This enables the application of microbial remediation technology to asphalt roofing membranes, giving them superior repair and protection properties. Furthermore, the entire process of microcapsule rupture, spore activation, and repair is intelligently triggered by a single condition: water intrusion, requiring no external intervention. Moreover, being entirely based on biotechnology, the remediation products are natural minerals that are ultimately biodegradable, meeting the requirements for green building materials. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0031] A self-healing waterproof membrane based on Staphylococcus aureus includes a plant-based bitumen substrate, uniformly dispersed heat-shielding microcapsules, and functional fillers; The heat-shielding microcapsules include: The core is a sodium alginate / calcium chloride hydrogel core that encapsulates dormant spores, nutrients, and nano-calcium oxalate seeds. The intermediate layer, which covers the core, is a phase change material layer, and the phase change temperature of the phase change material is 60~70℃. The outer shell, covering the intermediate layer, is a polydopamine interface bonding layer; The functional fillers include activated silica fume, nano titanium dioxide, quartz powder, wood fiber, and tire rubber powder.

[0032] In this way, a microcapsule with a triple protective structure was constructed; The hydrogel core, formed by sodium alginate-calcium chloride crosslinking, encapsulates dormant spores, nutrients, and nano-calcium oxalate seeds, providing a moist dormant environment for the spores. Then, an intermediate layer is constructed, in which a phase change material microcapsule is encapsulated on the outside of the inner hydrogel through in-situ polymerization. This forms a heat shield layer, so that when the external asphalt temperature rises sharply, the phase change material layer absorbs a large amount of heat through solid-liquid phase change, thereby ensuring that the core environmental temperature of the inner hydrogel remains stable for a long time and below the phase change temperature. This provides good thermal protection for the dormant spores and prevents the dormant spores from becoming inactive during the construction of the waterproof membrane. Finally, the constructed polydopamine interface outer layer utilizes the adhesive properties of the polydopamine interface to greatly improve the compatibility between the microcapsules and the hydrophobic plant-based bitumen substrate, prevent the thermal shielding microcapsules from agglomerating in large quantities, and enhance the mechanical properties of the roll material.

[0033] Furthermore, after the waterproof membrane is formed, when cracks appear and water enters, the moisture gradually softens and eventually dissolves the phase change material layer and the outer layer, exposing the internal hydrogel spore cores. Upon contact with water, the exposed spore cores are rapidly activated and begin metabolism. The oxalate ions secreted by the spores combine with calcium ions in the matrix and, using pre-placed nano-calcium oxalate seeds as templates, rapidly grow into calcium oxalate crystals, efficiently filling the cracks. This process is faster and more efficient than simply relying on spontaneous crystallization by spores.

[0034] Moreover, during the metabolism of *Stachys cerevisiae*, a variety of organic acids and antibacterial compounds are naturally produced. These products lower the pH value of the crack repair area and form a natural antibacterial microenvironment, which can effectively inhibit the growth of harmful microorganisms such as white rot fungi and Aspergillus, thus achieving repair as protection.

[0035] Preferably, the phase change material is a eutectic mixture of eicosanoic acid and docosanoic acid, wherein, by weight, the eicosanoic acid comprises 5-11.5 parts, the docosanoic acid comprises 2-4.5 parts, the nano-titanium dioxide has a particle size of 20-50 nm, and the quartz powder has a mesh size of 300 mesh.

[0036] Furthermore, by adjusting the dosage of eicosanoic acid and docosanoic acid, the eutectic phase transition temperature of the phase change material formed by the mixture of eicosanoic acid and docosanoic acid is controlled at 60~70℃, while ensuring the amount and thickness of the intermediate layer of the phase change material. This ensures that the phase change material layer has sufficient thickness and quantity to provide effective thermal shielding, and its specific eutectic composition ensures the stability of the phase transition temperature, thereby avoiding the problem of microbial inactivation during the high-temperature processing of asphalt.

[0037] Meanwhile, for the mixture of eicosanoic acid and docosanoic acid, the two acids are stirred and melted in a molten state, and then the melt is rapidly poured onto a pre-cooled metal tray and rapidly cooled and solidified at room temperature to form a solid eutectic mixture sheet. This rapid cooling process helps to suppress component segregation and form a uniform eutectic structure. Finally, the sheet is broken and ground into powder to obtain phase change material powder for later use.

[0038] Furthermore, the nutrient is glucose, and the particle size of the nano-calcium oxalate seed crystals is 20~100nm.

[0039] Furthermore, by weight, it includes: 100 parts plant-based asphalt, 10-20 parts heat-shielding microcapsules, 3-5 parts active silica fume, 0.5-2 parts nano titanium dioxide, 20-25 parts quartz powder, 3-5 parts wood fiber, and 15-20 parts tire rubber powder.

[0040] In addition, a method for preparing the aforementioned self-healing waterproof membrane based on *Stachys edulis* spores includes the following steps: S1. Preparation of heat-shielding microcapsules; S2. Heat the plant-based bitumen to a molten state, then cool it to 120~135℃; S3. Under stirring conditions, the heat-shielding microcapsules are added to the cooled plant-based asphalt and mixed at low speed until uniform to obtain a mixture. S4. Coat, cover, and cool the mixture to form a roll.

[0041] Preferably, in step S1, the heat-shielding microcapsules are prepared using microfluidic control technology, thereby accurately preparing microcapsules with a three-layer structure of "hydrogel-phase change material-polydopamine", including the following steps: S11. Prepare an aqueous core containing dormant *Stachys edulis* spores, nutrients, nano-calcium oxalate seeds, and sodium alginate; Specifically, sodium alginate can be added to deionized water to form a homogeneous solution. Then, nutrients, dormant *Stachys cerevisiae* spores, and nano-calcium oxalate seed crystals are added sequentially and stirred until there is no obvious sedimentation.

[0042] S12. Using a microfluidic device, the aqueous core solution and calcium chloride solution are mixed to form droplets and undergo a cross-linking reaction to form a hydrogel microsphere core; Specifically, the aforementioned aqueous core solution is used as the inner phase fluid, and vegetable oil or mineral oil and 1-2% of the surfactant Span 80 are used as the outer phase fluid. Monodisperse water-in-oil droplets, in which the outer phase fluid encapsulates the inner phase fluid, are prepared using a microfluidic device. The generated water-in-oil droplets are then added to a crosslinking agent solution prepared with 2-5 wt% calcium chloride aqueous solution, and allowed to stand for crosslinking for 10-20 minutes to ensure complete reaction and the formation of a mechanically stable hydrogel microsphere core.

[0043] S13. Molten phase change material is wrapped around the core of hydrogel microspheres, and after cooling, a phase change material intermediate layer is formed; S14. A polydopamine outer layer is formed outside the intermediate layer of the phase change material by in-situ polymerization of dopamine under weakly alkaline conditions.

[0044] Furthermore, in step S13, the phase change material is heated to 70~75°C and then encapsulated to form a molten state, thereby constructing a heat shield layer outside the fragile hydrogel microsphere core that can absorb a large amount of heat through solid-liquid phase change, thus protecting the internal spore dormant body from high temperature damage. Step S13 includes: S131. Select eicosanoic acid and docosanoic acid, mix them, and heat them in a water bath at 70~75℃ until they are completely melted into a transparent liquid, which is used as a phase change liquid; S132. The hydrogel microsphere core is dispersed in deionized water containing 1% Tween-80 as the inner phase fluid, and the molten phase change liquid is used as the intermediate phase fluid. The water core-phase change shell composite droplets are formed in a coaxial microfluidic device according to the flow rate ratio of inner phase fluid to intermediate phase fluid of 1:3. The temperature of the entire microfluidic device and receiving cell needs to be maintained at 70-75℃ to ensure that the phase change material remains liquid during the encapsulation process and does not solidify prematurely.

[0045] S133. Collect the composite droplets into a cooling container and cool the composite droplets to room temperature at a rate of 5~10℃ / min to obtain the phase change material intermediate layer.

[0046] During the cooling step, the phase change material shell is uniformly cooled and recrystallized from a liquid state into a solid state, ultimately forming a dense and fully encapsulated "hydrogel core / phase change material solid shell" microsphere.

[0047] Furthermore, step S14 is used to construct a hydrophilic interface layer with super-strong adhesion outside the hydrophobic phase change material shell, so as to greatly improve the compatibility between the microcapsules and the hydrophobic bitumen matrix and prevent phase separation and performance failure. S14 includes: S141. The obtained phase change material intermediate layer is dispersed in a Tris-HCl buffer solution with pH=8.5 to form a dispersion to provide conditions for initiating the spontaneous polymerization of dopamine. Dopamine hydrochloride powder is added to the dispersion according to a mass ratio of 1:5 between dopamine hydrochloride and the phase change material intermediate layer. S142. Place the mixture at room temperature and stir at 200-300 rpm for 12-24 hours. Throughout the process, dopamine monomers dissolved in the solution undergo oxidative self-polymerization under the catalysis of dissolved oxygen, generating polydopamine. Polydopamine molecules preferentially adsorb and deposit on the surface of hydrophobic phase change material microspheres, forming strong covalent and non-covalent bonds with the phase change material surface through their contained groups, thereby forming a uniform and dense polydopamine nanocoating in situ outside the microspheres.

[0048] S143. After the reaction is complete, the intermediate layer of the phase change material is collected by filtration, washed, and then dried at 30°C to obtain heat-shielding microcapsules.

[0049] Thus, in step S14, the room temperature and aqueous phase reaction conditions maximize the protection of the integrity of the internal phase change material layer and the hydrogel core.

[0050] Furthermore, in step S3, under stirring conditions of 120~135℃, the heat-shielding microcapsules, wood fiber, tire rubber powder, active silica fume, nano titanium dioxide and quartz powder are added sequentially, and stirred at a speed of 150-250 rpm for 20-40 minutes until they are evenly mixed.

[0051] In this step, heat-shielding microcapsules are added first. While ensuring that the stirring time allows for uniform dispersion, the stirring and mixing time is controlled to prevent the heat-shielding microcapsules from being exposed to a high-temperature environment in the molten asphalt matrix for an extended period. This controls the high-temperature exposure time of the heat-shielding microcapsules during asphalt processing, ensuring that the intermediate phase change layer of the heat-shielding microcapsules remains in a phase change state throughout the stirring and mixing process. This keeps the temperature of the internal core below the phase change temperature, effectively isolating the high-temperature environment from the internal microbial spores within a limited processing time window by allowing the intermediate phase change material to actively absorb heat and undergo a phase change. This overcomes the problem of spore inactivation caused by high processing temperatures.

[0052] Furthermore, the active silica fume, nano titanium dioxide, and quartz powder are premixed to form a composite filler before being added, and then simultaneously added to the mixing system as a composite filler.

[0053] The following section provides a detailed explanation of the specific preparation method. Example

[0054] Ingredients: 100 parts plant-based asphalt; 15 parts heat barrier microcapsules; functional fillers: 4 parts activated silica fume, 1 part nano titanium dioxide (30nm particle size), 22 parts 300-mesh quartz powder, 4 parts wood fiber, and 18 parts tire rubber powder.

[0055] The core of the thermal barrier microcapsule is a sodium alginate / calcium chloride hydrogel core, which encapsulates dormant Staphylococcus aureus, glucose, and 50nm nano-calcium oxalate seed crystals. Intermediate layer: a eutectic mixture of eicosanoic acid and docosanoic acid, with the phase transition temperature adjusted to approximately 65°C.

[0056] Outer shell: Polydopamine interface bonding layer.

[0057] Preparation method: Thermal barrier microcapsules were prepared using microfluidic technology.

[0058] The plant-based bitumen is heated to 180°C to melt, and then cooled to 130°C.

[0059] Under stirring at 200 rpm, first add the heat barrier microcapsules, then add wood fiber, tire rubber powder, and premixed active silica fume, nano titanium dioxide and quartz powder composite filler in sequence, and stir for a total of 30 minutes until uniform.

[0060] Finally, the material is coated, laminated, and cooled to form rolls.

[0061] In this embodiment, the spore survival rate was >90%. The crack completely closed after 7 days, and numerous calcium oxalate crystals were visible under a microscope. The repaired area showed a significant inhibitory effect on the growth of Aspergillus niger. The microcapsules were uniformly dispersed in the asphalt without significant aggregation. Example

[0062] In this embodiment, the difference from the previous embodiment is that eicosanoic acid is 10 parts and docosanoic acid is 3 parts. Under this ratio, the eutectic phase transition temperature of the intermediate layer phase change material is about 68°C.

[0063] In this embodiment, the effect is similar to that in Embodiment 1. Example

[0064] In this embodiment, the difference from that in Example 1 is that the amount of thermal barrier microcapsules is 10 parts, active silica fume is 3 parts, nano titanium dioxide is 0.5 parts, 300-mesh quartz powder is 20 parts, wood fiber is 3 parts, and tire rubber powder is 15 parts.

[0065] In this embodiment, the spore survival rate is >85%, while still maintaining good self-repair efficiency, antibacterial properties and compatibility.

[0066] Comparative Example 1 The difference from Example 1 is that no intermediate phase change layer is added when preparing the thermal barrier microcapsules. The thermal barrier microcapsules are composed only of a hydrogel core and a polydopamine shell.

[0067] In this comparative example, the spore survival rate was <5%, indicating almost no self-repair effect.

[0068] Comparative Example 2 Compared to Example 1, the difference is that there is no polydopamine shell, and the thermal barrier microcapsule consists only of a hydrogel core and a phase change material intermediate layer.

[0069] In this comparative example, the spore survival rate was approximately 80%, indicating that the phase change layer still functioned, but the mechanical properties were poor, and the microcapsules agglomerated severely in the asphalt, forming defect points.

[0070] Comparative Example 3 In this comparative example, the same amounts of dormant *Stachys eugenolus* spores, glucose, and nano-calcium oxalate seed crystals as in Example 1 were directly added to the plant-based bitumen. The functional filler was the same as in Example 1.

[0071] In this comparative example, the spore survival rate was 0, and there was no self-repair effect.

[0072] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A true spore self-healing waterproofing membrane, characterized in that, The plant-based asphalt base material, uniformly dispersed heat shielding microcapsules, and functional fillers are included. The heat shielding microcapsules include: a core, which is a sodium alginate / calcium chloride hydrogel core wrapped with true spore dormancy, nutrients, and nano calcium oxalate seeds; an intermediate layer, which is a phase change material layer wrapped outside the core, and the phase change temperature of the phase change material is 60-70℃; an outer shell, which is a polydopamine interface bonding layer wrapped outside the intermediate layer; The functional fillers include active silica ash, nano titanium dioxide, quartz powder, wood fiber, and tire rubber powder.

2. A true spore self-healing waterproofing membrane according to claim 1, characterized in that, The phase change material is a eutectic mixture of eicosanoic acid and docosanoic acid, and the weight ratio of eicosanoic acid to docosanoic acid is 5-11.5:2-4.

5. The particle size of the nano titanium dioxide is 20-50 nm, and the mesh number of the quartz powder is 300 mesh.

3. A true spore self-healing waterproofing membrane according to claim 1 or 2, characterized in that, The nutrients are glucose, and the particle size of the nano calcium oxalate seeds is 20-100 nm.

4. A true spore self-healing waterproofing membrane according to claim 1, characterized in that, The weight ratio of the plant-based asphalt, heat shielding microcapsules, active silica ash, nano titanium dioxide, quartz powder, wood fiber, and tire rubber powder is 100:10-20:3-5:0.5-2:20-25:3-5:15-20, respectively.

5. A method of producing the true spore self-repairing waterproofing membrane according to any one of claims 1 to 4, characterized in that, The method includes the following steps: S1. Preparing heat shielding microcapsules; S2. Heating the plant-based asphalt to a molten state and cooling it to 120-135℃; S3. Under stirring conditions, adding the heat shielding microcapsules to the cooled plant-based asphalt, mixing uniformly at low speed to obtain a mixture; S4. Coating, covering, and cooling the mixture to produce a roll.

6. The production method according to claim 5, wherein In step S1, the heat shielding microcapsules are prepared using microfluidic control technology, including the following steps: S11. Preparing an inner core aqueous solution containing true spore dormancy, nutrients, nano calcium oxalate seeds, and sodium alginate; S12. Using a microfluidic device, forming droplets of the inner core aqueous solution and calcium chloride solution and performing cross-linking reaction to form a hydrogel microsphere core; S13. Wrapping the molten phase change material outside the hydrogel microsphere core to form a phase change material intermediate layer after cooling; S14. Forming a polydopamine outer layer outside the phase change material intermediate layer through in-situ polymerization of dopamine under weak alkaline conditions.

7. The production method according to claim 6, wherein In step S13, the phase change material is heated to a molten state at 70-75℃ before being wrapped; Step S13 includes: S131. Selecting a mixture of eicosanoic acid and docosanoic acid, heating it in a water bath at 70-75℃ until it completely melts into a transparent liquid, and using it as a phase change liquid; S132. Dispersing the hydrogel microsphere core in deionized water containing 1% Tween-80 as the inner phase fluid, and using the molten phase change liquid as the intermediate phase fluid, according to a flow rate ratio of 1:3, forming water core-phase shell composite droplets in a coaxial microfluidic device; S133. Collecting the composite droplets into a cooling container, cooling the composite droplets to room temperature at a rate of 5-10℃ / min, and obtaining a phase change material intermediate layer.

8. The preparation method according to claim 6, characterized in that, Step S14 includes: S141. The obtained phase change material intermediate layer is dispersed in a Tris-HCl buffer solution with pH=8.5 to form a dispersion liquid, and dopamine hydrochloride powder is added to the dispersion liquid according to a mass ratio of 1:5 of dopamine hydrochloride to the phase change material intermediate layer; S142. The mixed system is placed at room temperature and stirred at a rotating speed of 200-300 rpm for 12-24 hours. S143. After the reaction is completed, the phase change material intermediate layer is collected by filtration, washed, and dried at 30°C to obtain the heat shielding microcapsule.

9. The production method according to claim 5, characterized by, In step S3, the heat shielding microcapsule, wood fibers, tire rubber powder, active silica ash, nano titanium dioxide, and quartz powder are sequentially added under stirring at 120-135°C, and stirred at a rotating speed of 150-250 rpm for 20-40 minutes until the mixture is uniform.

10. The method of claim 9, wherein, The active silica ash, nano titanium dioxide, and quartz powder are pre-mixed to form a composite filler before being added to the mixed system in the form of the composite filler.