3D printing plant ecological brick

Abstract

The invention discloses a 3D printing plant ecological brick in the field of ecological environment restoration and building materials. The ecological brick is mainly prepared by mixing sulphoaluminate cement, metakaolin, porous functional particles, a high-strength polymer binder, a thixotropic rheological regulator, intelligent nutrient release gel, a water reducing agent, a water-retaining agent and water according to a specific ratio and then carrying out three-dimensional printing molding. The core lies in three specific modified compounds: an organic-inorganic hybrid binder prepared through step-by-step polymerization and coupling reaction significantly enhances the interlayer bonding strength and durability of the material; the composite thixotropic agent is prepared through electrostatic self-assembly of nanofibers and nanosheets, so that the printing slurry is endowed with excellent extrusion formability and shape retention capability; the intelligent gel prepared by coating nutrients through double ion crosslinking can realize the response release of the nutrients along with the change of the pH value of the environment. The product is suitable for ecological slope protection engineering of riverway slopes.

Description

Technical Field

[0001] This invention relates to the field of ecological environment restoration and building materials technology, specifically to a 3D printed plant ecological brick. Background Technology

[0002] With increasing societal emphasis on ecological environmental protection, the negative ecological effects of rigid structures such as concrete and masonry, widely used in traditional slope protection engineering, are becoming increasingly prominent. While these structures effectively resist water erosion and soil loss, their enclosed surfaces completely disrupt the material cycle and energy exchange between soil, water, and biological communities, leading to a series of ecological and environmental problems such as river channelization, habitat loss, and a decline in the self-purification capacity of water bodies. Furthermore, rigid slope protection is difficult to support vegetation growth, resulting in significant disharmony with the surrounding natural landscape and disrupting the ecological balance and aesthetic value of the region. Therefore, developing a slope protection technology that can both stabilize slopes and restore vegetation and rebuild ecological functions has become a crucial issue urgently needing to be addressed in the fields of water conservancy engineering, transportation construction, and ecological restoration.

[0003] To reconcile the conflict between protection and ecology, various ecological slope protection technologies have emerged, such as vegetated concrete, ecological bags, and gabion nets. While these technologies have promoted vegetation restoration on slopes to some extent, they still have many limitations. First, it is often difficult to balance the mechanical properties and ecological functions of materials: high-strength materials typically have low porosity and high alkalinity, which is detrimental to root penetration and growth; conversely, ensuring suitable pore structure and nutrient conditions for plant growth often comes at the cost of sacrificing the material's mechanical strength and durability. Second, nutrient supply is mostly achieved through physical mixing, which is easily lost quickly under rainwater erosion or water immersion, resulting in short-lived fertilization effects that cannot meet the long-term growth needs of plants. Furthermore, traditionally manufactured ecological blocks have a simple structure and poor internal pore connectivity, making it difficult to create an ideal habitat conducive to root anchoring and microbial habitation. These shortcomings severely restrict the application effectiveness and long-term stability of existing ecological slope protection technologies, especially in harsh environments with high flow velocities and frequent water level fluctuations.

[0004] In recent years, 3D printing technology has provided a revolutionary means to construct functional components with complex macroscopic structures and precise material distribution, bringing new opportunities for the design of ecological slope protection materials. Theoretically, this technology can freely design and precisely manufacture interconnected porous network structures, providing optimal channels for plant root growth. However, the core bottleneck in applying this technology to the field of ecological slope protection lies in developing a new material system that combines excellent printability, mechanical strength, durability, and ecological activity. Ordinary printing materials cannot meet the performance requirements of ecological slope protection under harsh conditions such as long-term water erosion, wet-dry cycles, and freeze-thaw cycles. Therefore, it is urgent to develop printing materials specifically for ecological slope protection through innovation in materials science. These materials must be able to simultaneously solve key scientific problems such as rheological behavior control during the printing process, interlayer bonding strengthening, long-term water stability assurance, and intelligent nutrient supply, thereby achieving a high degree of integration between engineering protection and ecological restoration functions. Summary of the Invention

[0005] The purpose of this invention is to provide a 3D printed plant ecological brick, which solves the technical problems of existing ecological slope protection materials having difficulty in synergistic mechanical properties and ecological functions, easy loss and failure of traditional nutrient supply methods, and poor adaptability of 3D printing technology.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A 3D-printed plant-based eco-brick comprises the following raw materials in parts by weight:

[0008] Sulfoaluminate cement: 200-350 parts by weight;

[0009] Metakaolin: 50-150 parts by weight;

[0010] KZ granules: 400-600 parts by weight;

[0011] High-strength cross-linked polymer adhesive: 30-80 parts by weight;

[0012] Thixotropic rheological property modifier: 5-20 parts by weight;

[0013] pH-responsive nutrient slow-release gel: 20-60 parts by weight;

[0014] Polycarboxylate superplasticizer: 2-8 parts by weight;

[0015] Hydroxypropyl methylcellulose: 0.5-2 parts by weight;

[0016] Water: 150-250 parts by weight;

[0017] The preparation method of the high-strength cross-linked polymer adhesive includes: A1, purging nitrogen gas into a four-necked flask for purging, then adding deionized water and anhydrous ethanol, stirring and heating to 64-66℃; then adding 2-acrylamido-2-methylpropanesulfonic acid and β-hydroxyethyl methacrylate, stirring until completely dissolved to form a homogeneous solution; then adding ammonium persulfate, maintaining the reaction at 64-66℃ to obtain a prepolymer solution; A2, then first adding anhydrous ethanol solution of tetraethyl orthosilicate, continuing the reaction after the addition is complete, then adding anhydrous ethanol solution of silane coupling agent; after the addition is complete, adjusting the pH of the system to 8.0-8.5 with sodium hydroxide aqueous solution, and continuing the reaction at 64-66℃.

[0018] In this invention, the KZ particle preparation steps include: firstly, weighing the raw materials according to the following weight proportions: 30-50 parts of plant-derived compost, 10-20 parts of sodium-based bentonite (montmorillonite content ≥85%), 5-15 parts of nitrogen-phosphorus-potassium compound fertilizer (N-P2O5-K2O=15-15-15), 20-40 parts of 42.5 grade sulfoaluminate cement, and 5-15 parts of Class F II fly ash (fineness ≤20%). All the above dry materials are then added to a twin-shaft paddle mixer and premixed thoroughly at medium speed for 10-15 minutes to ensure uniform distribution of each component. Subsequently, the mixer's spray system is started. Slowly add 15%-20% clean tap water (by weight of dry material) to the mixture, controlling the droplet size and spray speed to gradually wet the material and begin forming tiny particle nuclei. Then, transfer this premixed wet material to a disc granulator with adjustable speed. By adjusting the granulator's rotation speed to 20-35 r / min and the inclination angle to 45-55°, the wet material adheres to each other during rolling, gradually growing larger by layering. Intermittent spraying of atomized water controls the particle growth rate, ultimately forming raw material balls with a uniform particle size of 5-10 mm. Spread the raw material balls evenly on a heat-resistant tray, with a thickness not exceeding 50 mm. The particles, after being heated to mm, are immediately placed in a saturated steam curing chamber for rapid curing. The curing process consists of three stages: first, pre-curing in an environment with a temperature of 50-60℃ and a relative humidity of ≥90% for 3-4 hours; then, raising the temperature to 85-95℃ at a rate not exceeding 15℃ / h, and maintaining this temperature and humidity for 8-12 hours; finally, stopping the steam supply and allowing the temperature to drop naturally to below 40℃ before removing the particles from the chamber; the particles are then immediately transferred to a circulating ventilation drying chamber and dried under hot air conditions of 75-85℃ until the moisture content is ≤2%. Finally, after being screened by a vibrating screen to remove broken fine powder, a high-strength, porous honeycomb structure, nutrient-rich, and water-stable KZ particle product is obtained, which is then sealed and packaged for later use.

[0019] According to a preferred embodiment of the present invention, the plant-derived compost was purchased from Tianjin Kunhe Biotechnology Group Co., Ltd.

[0020] According to a preferred embodiment of the present invention, the sodium-based bentonite was purchased from Jianping Huiying Chemical Co., Ltd.

[0021] According to a preferred embodiment of the present invention, the nitrogen-phosphorus-potassium compound fertilizer (N-P2O5-K2O=15-15-15) was purchased from Hubei Xinyangfeng Fertilizer Co., Ltd.

[0022] According to a preferred embodiment of the present invention, the 42.5 grade sulfoaluminate cement was purchased from Tangshan Liujiu Cement Co., Ltd.

[0023] According to a preferred embodiment of the present invention, the fly ash was purchased from Ningbo Siheng Building Materials Co., Ltd.

[0024] In this invention, the KZ particles are a granular material consisting of an inorganic cementitious material (such as cement or metakaolin) as the outer shell, encapsulating an internal organic-inorganic composite core material (organic matter, nutrients, bentonite, etc.). Through a rapid curing process, a granular material with a honeycomb-like internal structure is formed. These particles have high strength and are resistant to long-term immersion and erosion by water flow; the material itself contains nutrients suitable for plant growth and can also store sufficient water and nutrients; simultaneously, its porous structure facilitates the penetration and absorption of nutrients and water by plant roots.

[0025] In this invention, the core reaction mechanism of the high-strength crosslinked polymer binder lies in constructing an interpenetrating network structure where the organic and inorganic phases are tightly bonded by chemical bonds through a stepwise synthesis strategy, thereby achieving synergistic performance enhancement. The preparation process begins with a free radical copolymerization reaction under an inert atmosphere. In a mixed solvent of warm water and ethanol, acrylamide monomers containing strongly polar and hydrophilic sulfonic acid groups and acrylate monomers containing active hydroxyl groups copolymerize under the action of an initiator, forming linear or slightly branched polymer prepolymer chains. This step is fundamental to the formation of the organic polymer backbone. The introduction of sulfonic acid groups aims to endow the polymer chains with good water dispersibility, ion exchange capacity, and strong adsorption to the surface of inorganic materials, while the hydroxyl groups provide active sites for subsequent coupling reactions. The subsequent stepwise dropwise addition process is crucial to the entire reaction. First, a hydrolyzable inorganic silicon source precursor is added. This precursor rapidly undergoes a hydrolysis reaction under warm water and a slightly acidic system environment, generating highly reactive silanol groups. These silanol groups then undergo a condensation reaction, initiating the initial formation of an inorganic siloxane network. Allowing it to react for a period of time allows the inorganic network to develop a certain size and stability, creating conditions for subsequent hybridization. Subsequently, a silane coupling agent containing a hydrolyzable alkoxy group at one end and an organic functional group at the other is added. At this point, the alkoxy group of the coupling agent molecule rapidly participates in the formation of the ongoing inorganic siloxane network, covalently linking it through siloxane bonds; simultaneously, the organic functional group (such as an amino group) at the other end undergoes acid-base neutralization or forms ionic bonds with the sulfonic acid groups on the pre-synthesized polymer prepolymer chain, and undergoes a condensation reaction with the hydroxyl groups on the polymer chain. This step acts like a "molecular bridge," firmly bonding the growing inorganic siloxane network to the organic polymer network. Finally, the continuous reaction under weakly alkaline conditions promotes a more thorough hydrolysis-condensation reaction, allowing the organic polymer network and the inorganic siloxane network to interpenetrate and entangle with each other, connected by numerous silicon-oxygen bonds and ionic / covalent bonds, ultimately forming a highly cross-linked, homogeneous organic-inorganic hybrid system. This unique structure combines the flexibility and high adhesion of organic polymers with the rigidity, weather resistance, and thermal stability of inorganic silicon materials, thus effectively bridging cement hydration products, functional aggregates, and other components, significantly enhancing the bond strength between printed layers and the overall mechanical properties and durability of the material.

[0026] According to a preferred embodiment of the present invention, in step A1, the reaction time at 64-66°C is 1-2 hours.

[0027] According to a preferred embodiment of the present invention, in step A2, the reaction continues at 64-66°C for 3-5 hours.

[0028] According to a preferred embodiment of the present invention, the preparation method of the thixotropic rheological property modifier includes: B1, dispersing microcrystalline cellulose in a pre-cooled ionic liquid of concentrated phosphoric acid and urea, and mechanically stirring at -9 to -11°C; then adding chlorosulfonic acid to undergo a sulfonation reaction; after the reaction, pouring the mixture into ice-cold ethanol and precipitating it, collecting the precipitate by centrifugation and repeatedly washing it with ethanol until neutral, and finally redispersing it in deionized water, and obtaining a sulfonated cellulose nanofiber suspension by ultrasonic treatment; B2, dispersing lithium saponite in deionized water, adding hexadecyltrimethylammonium bromide, stirring and modifying it in a water bath at 68-72°C, centrifuging and washing it after the reaction, and redispersing it in water to form an organic lithium saponite suspension; finally, mixing the prepared sulfonated cellulose nanofiber suspension with the organic lithium saponite suspension, placing it in a high-speed shear emulsifier, shearing it to form a nanocomposite colloidal dispersion; transferring the nanocomposite colloidal dispersion to a freeze-drying tray, pre-freezing it at -48 to -52°C, and then drying it in a freeze dryer.

[0029] In this invention, the preparation of the thixotropic modifier is a typical process of nanomaterial modification and layer-by-layer self-assembly based on electrostatic interactions. The goal is to construct a three-dimensional nanonetwork that can be reversibly disassembled and reassembled under shear force, thereby precisely controlling the rheological properties of the printing paste. The mechanism begins with the chemical modification of natural cellulose fibers. Under strongly acidic and low-temperature conditions, highly hydrophilic sulfonic acid groups are covalently grafted onto the cellulose molecular chains through a sulfonation reaction. This greatly promotes the dispersion and defibrillation of cellulose fibers in water, resulting in nanoscale filaments through ultrasonic treatment. Furthermore, it introduces a large number of negatively charged functional groups, giving these nanofibers a stable negative charge on their surface, providing a foundation for subsequent electrostatic self-assembly. Parallel to this is the organic modification of layered silicate clay minerals. Natural sodium-based clay also carries a negative charge on its lamellar surface in water, with cations balancing the charge between the lamellar layers. When an excess of cationic surfactant is added and treated under heating conditions, the cationic head groups at the hydrophobic tails of the surfactant insert into the clay layers through ion exchange. This not only increases the interlayer spacing but, more importantly, the long alkyl chains change the surface properties of the clay layers from hydrophilic to oleophilic (hydrophobic). Even more crucially, due to the physical adsorption of the excess surfactant, the entire modified clay layer surface acquires a stable positive charge. When the negatively charged nanocellulose filaments and the positively charged organic clay nanosheets meet in an aqueous solution, they spontaneously bind due to the strong electrostatic attraction between opposite charges. The nanofibers adsorb onto the surface of the nanosheets, while the nanosheets interweave between the nanofibers, forming a robust three-dimensional nanonetwork with a "house-like" structure through electrostatic interaction and physical entanglement. This network, in a static state, can firmly lock water molecules and solid particles (such as cement and aggregates) within its mesh, imparting extremely high static yield stress to the slurry, thereby preventing solid particle sedimentation and ensuring that the printed components maintain their shape and do not collapse after deposition. When subjected to high external shear forces (such as extrusion through a printer screw), this electrostatic network structure is temporarily and reversibly disrupted and broken down. The nanofibers and nanosheets align themselves along the flow direction, causing a sharp drop in slurry viscosity, resulting in excellent flowability and easy extrusion. Once extrusion stops and the shear force disappears, the strong electrostatic attraction immediately drives the nanoparticles to rebuild the three-dimensional network, and the viscosity recovers instantly. This achieves the excellent thixotropic properties of the slurry—"shear thinning and settling thickening"—perfectly matching the process requirements of 3D printing.

[0030] According to a preferred embodiment of the present invention, in step B1, the mechanical stirring time at -9~-11°C is 1-2 hours, and the sulfonation reaction lasts for 2-4 hours.

[0031] According to a preferred embodiment of the present invention, in step B2, the stirring modification time in a water bath at 68-72℃ is 4-6 hours; the pre-freezing time at -48~-52℃ is 4-6 hours.

[0032] According to a preferred embodiment of the present invention, the method for preparing the pH-responsive nutrient sustained-release gel includes:

[0033] C1. Add humic acid, potassium dihydrogen phosphate, potassium nitrate, and ammonium chloride to deionized water and stir at 38-42°C to form a nutrient complex. Then, dissolve sodium alginate and chitosan quaternary ammonium salt in a dilute acid solution containing glacial acetic acid and stir at low speed overnight to form a premix.

[0034] C2. Then, the nutrient complex slurry is slowly added to the premixed solution and stirred with a mechanical stirrer; then, the mixed slurry is added dropwise to a mixed crosslinking agent solution containing calcium chloride and sodium tripolyphosphate using the electrostatic droplet addition method to form gel beads; after the gel beads have matured in the crosslinking agent solution, they are washed with deionized water.

[0035] C3. Pre-freeze the gel beads at -40~-42℃, then transfer them to a freeze dryer for freeze drying to constant weight; grind the dried gel beads at low temperature using a ball mill.

[0036] In this invention, the design mechanism of the smart gel lies in utilizing the sensitivity of biopolymers to environmental pH. Through dual ionic cross-linking, plant nutrients are encapsulated within a smart network, achieving linkage between nutrient release and plant root physiological activities. The preparation process begins with the pretreatment of the nutrient source. Natural humic acid molecules contain numerous functional groups such as carboxyl and phenolic hydroxyl groups. Under mild heating conditions, these groups can complex and exchange with nutrient ions such as ammonium and potassium ions in the solution, forming a relatively stable nutrient complex. This prevents high concentrations of inorganic salt ions from prematurely damaging the polymeric gel network during subsequent gelation steps and converts fast-acting nutrients into a slow-release form, laying the foundation for smart release. The subsequent process involves the dual construction of the gel network, which is crucial for achieving pH response. First, two naturally polysaccharides with opposite charges, anionic sodium alginate and cationic chitosan quaternary ammonium salt, are dissolved together. They form a polyelectrolyte complex through electrostatic attraction, a physical cross-linking point that initially establishes the basic structure of the gel. Next, the mixture containing the nutrient complex was dropwise added to a solution containing a dual cross-linking agent. The first cross-linking reaction occurs when the guluronic acid units on the sodium alginate molecular chain specifically coordinate with calcium ions, forming a classic "egg-box" structure—a highly robust ionic cross-linking network. Almost simultaneously, the second cross-linking reaction occurs: negatively charged tripolyphosphate ions act as cross-linking agents, rapidly reacting with the ammonium groups on the positively charged chitosan quaternary ammonium salt molecular chain to form another interwoven network. The final result is a dual-network hydrogel where the sodium alginate-calcium ion network and the chitosan quaternary ammonium salt-tripolyphosphate network interpenetrate. This network tightly encapsulates the nutrient complex within. Its intelligent responsiveness stems from the sensitivity of the numerous ionizable groups (carboxyl and ammonium groups) within the network to hydrogen ion concentration. When the environment is alkaline (e.g., when microbial activity is vigorous and organic matter is decomposed to produce ammonium ions), the ionization degree of the carboxyl groups on the sodium alginate chains increases, the negative charge repulsion between chain segments increases, leading to network swelling, increased pore size, and accelerated nutrient release. When the environment is acidic (such as when plant roots secrete carbonic acid or when organic acids are present), the ammonium matrix protonation of the chitosan quaternary ammonium salt chains is enhanced, and the positive charge repulsion also causes the network to swell, promoting release. In a neutral environment, the network remains relatively contracted, and release is slow. This characteristic allows the nutrient supply rate to match the biological activity of the rhizosphere microenvironment, achieving on-demand supply, greatly improving fertilizer utilization and prolonging fertilizer effectiveness.

[0037] According to a preferred embodiment of the present invention, in step C1, the stirring time at 38-42°C is 2-4 hours.

[0038] According to a preferred embodiment of the present invention, in step C2, the stirring time of the mechanical stirrer is 1-2 hours; the maturation time of the gel beads in the crosslinking agent solution is 4-6 hours.

[0039] According to a preferred embodiment of the present invention, in step C3, the pre-freezing time at -40~-42℃ is 6-8h, and the freeze-drying temperature is -48~-52℃.

[0040] In this invention, the entire preparation of the eco-brick involves the synergistic integration of multiple physical and chemical reaction processes at both the macroscopic and microscopic scales. Its final performance stems from the exquisite coordination and interaction of its components. First, in the dry-mixing stage, various powdered raw materials (cementing materials, functional particles, and various modifier powders) are mechanically stirred to achieve physical homogeneity, ensuring the homogeneity of subsequent hydration reactions and functional performance. Upon the addition of water, a complex and synergistic reaction process immediately commences. The sulfoaluminate cement in the cementing material rapidly hydrates, generating a large amount of ettringite, hydrated calcium silicate, and other products, forming the main rigid framework for the overall brick strength. This process is rapid and results in high early strength, ensuring immediate shape stability after printing. Metakaolin, utilizing its pozzolanic effect, consumes the calcium hydroxide produced during cement hydration, generating additional hydrated calcium aluminosilicate with cementing properties. This improves the density and later strength of the matrix while reducing the alkalinity of the system, creating a more favorable microenvironment for plant growth. Polycarboxylate superplasticizer molecules adsorb onto the surface of cement particles, dispersing the particles through a strong steric hindrance effect and releasing the encapsulated free water, thus achieving good initial workability of the slurry at extremely low water-cement ratios. Hydroxypropyl methylcellulose molecules form a hydration film in the aqueous phase, playing a role in water retention, thickening, and auxiliary stabilization, preventing water from evaporating too quickly or being absorbed by porous aggregates, and ensuring sufficient hydration reaction. Simultaneously, various functional modifiers begin to exert their unique effects. The thixotropic modifier rapidly establishes a three-dimensional nanonetwork, endowing the slurry with the required printability, making it extrudable, non-clogging, and non-collapse-resistant. The polymer binder, with its organic-inorganic hybrid structure, tightly bridges and encapsulates hydration products, aggregate particles, and other interfaces, greatly enhancing interfacial adhesion and material toughness. Smart gel particles dispersed in the matrix serve as nutrient reservoirs, and their own porous structure also contributes to the porosity. The porous functional aggregate acts as a miniature "reservoir and fertilizer tank," storing water and nutrients internally. Its surface pores provide anchoring points for the penetration of cement paste, forming a strong mechanical interlocking. Finally, using 3D printing technology, this functional composite material with complex rheological behavior is precisely stacked layer by layer to construct the pre-defined macroporous structure. During the subsequent curing process, hydration reactions continue, strength develops, and the components, through physical entanglement, chemical bonding, and mechanical interlocking, ultimately form a strong, durable, porous, and intelligently responsive organic whole. Its macroporous structure provides growth channels for plant roots, the intelligent gel releases nutrients according to environmental needs, and the high-strength matrix resists water erosion, thus perfectly meeting the stringent requirements of ecological slope protection engineering for both structural stability and ecological functionality.

[0041] The beneficial effects of this invention are as follows:

[0042] The 3D-printed plant-based eco-brick provided by this invention, through its unique material formulation and structural design, exhibits outstanding comprehensive technical effects, successfully solving the key problem of existing eco-friendly slope protection materials struggling to coordinate mechanical properties, construction adaptability, and ecological functions. Firstly, this eco-brick demonstrates excellent mechanical properties and long-term durability. The cementitious system based on sulfoaluminate cement and metakaolin provides a rapidly hardening and high-strength basic framework, while specially designed porous functional particles, as the core aggregate, not only possess high strength and water erosion resistance but also form a strong mechanical bond with the matrix. Crucially, the introduced high-strength cross-linked polymer binder constructs a strong and tough organic-inorganic hybrid interface between the inorganic cementitious network and the organic aggregate, greatly enhancing the material's integrity, interlayer adhesion, and flexural strength. This enables it to effectively resist the long-term erosion and impact of water flow and waves, meeting the high standards of mechanical properties and durability required for slope protection projects in harsh environments.

[0043] Secondly, this product perfectly balances the adaptability to 3D printing processes with the precision of molding. The thixotropic rheological modifier in the formula constructs a stable three-dimensional network structure in the slurry through the electrostatic self-assembly of nanofibers and nanosheets, endowing the material with unique rheological properties: during high-shear printing extrusion, the slurry viscosity decreases and fluidity increases, ensuring smooth and unobstructed extrusion; once extrusion stops and the shear force disappears, the structure rapidly recovers, and the viscosity instantly increases, thus giving the printed lines excellent shape retention capabilities and effectively preventing deformation and collapse during stacking. This excellent thixotropy and extrudability enable the precise printing of complex hollow mesh structures, providing optimal penetration space for plant roots while ensuring construction efficiency and component geometric accuracy.

[0044] Finally, this invention achieves intelligent and long-lasting ecological restoration. The continuous, interconnected porous structure within the ecological brick provides an ideal channel for plant root spread, microbial habitat, and water and nutrient transport. Its contained intelligent nutrient-releasing gel overcomes the limitations of traditional physically blended fertilizers, which are prone to loss. It can sense changes in the microenvironment's pH caused by plant root activity or microbial metabolism, and intelligently regulate the nutrient release rate through its own network swelling behavior. This achieves a dynamic match between nutrient supply and plant needs, greatly improving nutrient utilization efficiency and extending the duration of fertilizer effectiveness. This allows the ecological brick to not only rapidly establish vegetation cover in the short term but also maintain the health and stability of the ecosystem in the long term, truly achieving a deep integration and long-lasting effect of engineering protection and ecological function. Detailed Implementation

[0045] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0046] The following is information on domestic suppliers of key related equipment and materials:

[0047] The sulfoaluminate cement was purchased from Tangshan Arctic Bear Building Materials Co., Ltd.

[0048] The metakaolin was purchased from Inner Mongolia Chaopai Building Materials Technology Co., Ltd.

[0049] The polycarboxylate superplasticizer was purchased from Jiangsu Subote New Material Co., Ltd.

[0050] The hydroxypropyl methylcellulose was purchased from Shandong Heda Co., Ltd.

[0051] The four-necked flask was purchased from Shanghai Spencer Scientific Instruments Co., Ltd.

[0052] The 2-acrylamide-2-methylpropanesulfonic acid was purchased from Shandong Xinhe New Materials Co., Ltd.

[0053] The β-hydroxyethyl methacrylate was purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0054] The ammonium persulfate was purchased from Tianjin AkzoNobel Peroxide Co., Ltd.

[0055] The tetraethyl orthosilicate was purchased from Hubei Xinlantian New Materials Co., Ltd.

[0056] The silane coupling agent is γ-aminopropyltriethoxysilane, which was purchased from Nanjing Shuguang Chemical Group Co., Ltd.

[0057] The sodium hydroxide was purchased from Wanhua Chemical Group Co., Ltd.

[0058] The microcrystalline cellulose was purchased from Huzhou Zhanwang Pharmaceutical Co., Ltd.

[0059] The concentrated phosphoric acid was purchased from Sichuan Chenghong Phosphoric Chemical Co., Ltd.

[0060] The urea was purchased from Hubei Yihua Group Co., Ltd.

[0061] The chlorosulfonic acid was purchased from Jiahe Energy Chemical Co., Ltd.

[0062] The icy ethanol was purchased from Jiangsu Hualun Chemical Co., Ltd.

[0063] The lithium saponite was purchased from Anmi Micro-Nano Technology Co., Ltd.

[0064] The hexadecyltrimethylammonium bromide was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0065] The freeze dryer was purchased from Beijing Boyikang Experimental Instrument Co., Ltd.

[0066] The humic acid was purchased from Xinjiang Shuanglong Humic Acid Co., Ltd.

[0067] The potassium dihydrogen phosphate was purchased from Sichuan LanHai Chemical (Group) Co., Ltd.

[0068] The potassium nitrate was purchased from Qinghai Salt Lake Industry Co., Ltd.

[0069] The ammonium chloride was purchased from Tianjin Bohua Yongli Chemical Co., Ltd.

[0070] The sodium alginate was purchased from Qingdao Mingyue Seaweed Group Co., Ltd.

[0071] The chitosan quaternary ammonium salt was purchased from Wuhan Yuancheng Gongchuang Technology Co., Ltd.

[0072] The glacial acetic acid was purchased from Jiangsu Suopu (Group) Co., Ltd.

[0073] The calcium chloride was purchased from Shandong Haihua Co., Ltd.

[0074] The sodium tripolyphosphate was purchased from Hubei Xingfa Chemical Group Co., Ltd.

[0075] Example 1

[0076] In this embodiment, 3D printed plant ecological bricks were prepared using the following raw material ratios: 300g sulfoaluminate cement, 100g metakaolin, 500g KZ particles, 50g high-strength cross-linked polymer binder, 12g thixotropic rheological property modifier, 40g pH-responsive nutrient slow-release gel, 5g polycarboxylate superplasticizer, 1.2g hydroxypropyl methylcellulose, and 200g water. The preparation method of the high-strength cross-linked polymer adhesive is as follows: First, add 300g of deionized water and 100g of anhydrous ethanol to a 2000mL four-necked flask, purge with nitrogen for gas replacement protection, start stirring and heat to 65℃ and maintain constant temperature; then add 50g of 2-acrylamide-2-methylpropanesulfonic acid and 20g of β-hydroxyethyl methacrylate, stir until completely dissolved to form a homogeneous solution; then add 1.5g of ammonium persulfate, maintain the reaction at 65℃ for 1.5 hours to obtain a prepolymer solution; then slowly add 40g of anhydrous ethanol solution containing 15g of tetraethyl orthosilicate, and continue the reaction for 1 hour after the addition is complete; then slowly add 30g of anhydrous ethanol solution containing 10g of silane coupling agent; after the addition is complete, adjust the pH of the system to 8.2 with a 10% sodium hydroxide aqueous solution, and continue the reaction at 65℃ for 4 hours to obtain the final high-strength cross-linked polymer adhesive. The preparation method of the thixotropic rheological property modifier is as follows: 20g of microcrystalline cellulose is dispersed in a low-temperature eutectic solvent prepared by pre-cooling 300g of concentrated phosphoric acid and 15g of urea, and mechanically stirred at 300rpm for 1.5 hours at -10℃; then 8g of chlorosulfonic acid is slowly added, and a sulfonation reaction occurs for 3 hours; after the reaction, the mixture is poured into 1000g of ice-cold ethanol and precipitated. The precipitate is collected by centrifugation and repeatedly washed with ethanol until neutral. Finally, it is redispersed in 500g of deionized water and ultrasonically treated at 1000W for 30 minutes to obtain a sulfonated cellulose nanofiber suspension; 10g of lithium saponite is dispersed in 200g of deionized water, and hexadecyltrimethyl... 3.5 g of ammonium bromide was modified by stirring at 200 rpm in a 70°C water bath for 5 hours. After the reaction, the mixture was centrifuged, washed, and redispersed in 150 g of water to form an organic lithium saponite suspension. Finally, the prepared sulfonated cellulose nanofiber suspension and the organic lithium saponite suspension were mixed at a mass ratio of 2:1 and placed in a high-speed shear emulsifier. The mixture was sheared at 10,000 rpm for 30 minutes to form a stable nanocomposite colloidal dispersion. The nanocomposite colloidal dispersion was transferred to a freeze-drying tray and pre-frozen at -50°C for 5 hours. Then, it was dried in a freeze dryer at -50°C and 0.1 mbar for 48 hours to obtain the final thixotropic rheological property modifier powder.The preparation method of pH-responsive nutrient slow-release gel is as follows: 15g of humic acid, 10g of potassium dihydrogen phosphate, 8g of potassium nitrate, and 5g of ammonium chloride are added to 50g of deionized water and stirred at 150rpm for 3 hours at 40℃ to form a homogeneous nutrient complex; then, 8g of sodium alginate and 4g of chitosan quaternary ammonium salt are dissolved in 500g of deionized water containing 5g of glacial acetic acid, and stirred at low speed of 50rpm overnight to form a premix; then, the nutrient complex slurry is slowly added to the premix, and stirred at 200rpm for 1.5 hours using a mechanical stirrer; then... Electrostatic droplet addition was used to form gel beads. The mixed slurry was added dropwise to a 500g mixed crosslinking agent solution containing 10g calcium chloride and 5g sodium tripolyphosphate to form gel beads with uniform particle size. After the gel beads were matured in the crosslinking agent solution for 5 hours, they were washed three times with deionized water. The gel beads were pre-frozen at -41℃ for 7 hours, and then freeze-dried in a freeze dryer at -50℃ and 0.05mbar for 36 hours until constant weight was achieved. The dried gel beads were then ground in a ball mill at -20℃ to a powder with a particle size of less than 100μm to obtain the final pH-responsive nutrient slow-release gel. Preparation of 3D-printed plant eco-bricks: 300g of sulfoaluminate cement, 100g of metakaolin, 500g of KZ particles, 50g of prepared high-strength cross-linked polymer binder, 12g of thixotropic rheological property modifier, 40g of pH-responsive nutrient slow-release gel, 5g of polycarboxylate superplasticizer, and 1.2g of hydroxypropyl methylcellulose were added to a horizontal mixer and dry-mixed at 60 rpm for 5 minutes until homogeneous. Then, 200g of water was slowly added, and the speed was increased to 120 rpm, and wet-mixed for 8 minutes to form a uniform printing slurry. The slurry was loaded into the feed hopper of a screw extruder 3D printer, and the printing layer thickness was set to 10mm, the extrusion speed to 40mm / s, and the printing path to a grid structure, and the slurry was printed layer by layer. After printing, the slurry was cured for 28 days at a temperature of 20℃ and a relative humidity of 95% to obtain the final 3D-printed plant eco-brick product.

[0077] Example 2

[0078] The specific implementation method is the same as in Example 1, except that in this example, the raw material ratio for preparing 3D printed plant ecological bricks is as follows: 250g of sulfoaluminate cement, 80g of metakaolin, 450g of KZ particles, 40g of high-strength cross-linked polymer binder, 8g of thixotropic rheological property modifier, 30g of pH-responsive nutrient slow-release gel, 3g of polycarboxylate superplasticizer, 0.8g of hydroxypropyl methylcellulose, and 180g of water. Preparation of high-strength cross-linked polymer adhesive: Add 240g of deionized water and 80g of anhydrous ethanol to a 2000mL four-necked flask, purge with nitrogen, and heat to 65℃; add 40g of 2-acrylamide-2-methylpropanesulfonic acid and 16g of β-hydroxyethyl methacrylate, stir to dissolve, then add 1.2g of ammonium persulfate, and maintain the reaction at 65℃ for 1.5 hours; first add 32g of anhydrous ethanol solution containing 12g of tetraethyl orthosilicate, and continue the reaction for 1 hour after the addition is complete; then add 24g of anhydrous ethanol solution containing 8g of silane coupling agent, adjust the pH to 8.2 with sodium hydroxide aqueous solution, and continue the reaction at 65℃ for 4 hours. Preparation of thixotropic and rheological property modifiers: 16g of microcrystalline cellulose was dispersed in a pre-cooled mixture of 240g of concentrated phosphoric acid and 12g of urea, and stirred at -10℃ for 1.5 hours; 6.4g of chlorosulfonic acid was added, and the reaction was carried out for 3 hours; the precipitate was poured into ice-cold ethanol, centrifuged and washed until neutral, and dispersed to obtain a suspension of sulfonated cellulose nanofibers; 8g of lithium saponite was dispersed in 160g of water, 2.8g of hexadecyltrimethylammonium bromide was added, and the mixture was stirred at 70℃ for 5 hours for modification, and centrifuged and washed to obtain an organic lithium saponite suspension; the two suspensions were mixed at a mass ratio of 2:1, sheared at 10000rpm for 30 minutes, pre-frozen at -50℃ for 5 hours, and freeze-dried to obtain the product. Preparation of pH-responsive nutrient sustained-release gel: 12g humic acid, 8g potassium dihydrogen phosphate, 6.4g potassium nitrate, and 4g ammonium chloride were added to 40g water and stirred at 40℃ for 3 hours. Separately, 6.4g sodium alginate and 3.2g chitosan quaternary ammonium salt were dissolved in 400g water containing 4g glacial acetic acid and stirred overnight. The nutrient complex was added to the premix and mechanically stirred for 1.5 hours. Dropwise, a mixed crosslinking agent solution containing 8g calcium chloride and 4g sodium tripolyphosphate was added to 400g to form gel beads, which were then matured for 5 hours. After washing, the gel beads were pre-frozen at -41℃ for 7 hours, freeze-dried at -50℃, and ground to obtain the product. The raw materials were mixed and stirred for 5 minutes, and then printed using a screw extrusion 3D printer and cured at room temperature for 28 days.

[0079] Example 3

[0080] The specific implementation method is the same as in Example 1, except that in this example, the raw material ratio for preparing 3D printed plant ecological bricks is as follows: 320g of sulfoaluminate cement, 120g of metakaolin, 550g of KZ particles, 60g of high-strength cross-linked polymer binder, 15g of thixotropic rheological property modifier, 50g of pH-responsive nutrient slow-release gel, 6g of polycarboxylate superplasticizer, 1.5g of hydroxypropyl methylcellulose, and 220g of water. Preparation of high-strength cross-linked polymer adhesive: Add 360g of deionized water and 120g of anhydrous ethanol to a 2000mL four-necked flask, purge with nitrogen, and heat to 65℃; add 60g of 2-acrylamide-2-methylpropanesulfonic acid and 24g of β-hydroxyethyl methacrylate, stir to dissolve, then add 1.8g of ammonium persulfate, and maintain the reaction at 65℃ for 1.5 hours; first add 48g of anhydrous ethanol solution containing 18g of tetraethyl orthosilicate, and continue the reaction for 1 hour after the addition is complete; then add 36g of anhydrous ethanol solution containing 12g of silane coupling agent, adjust the pH to 8.2 with sodium hydroxide aqueous solution, and continue the reaction at 65℃ for 4 hours. Preparation of thixotropic and rheological property modifiers: 24g of microcrystalline cellulose was dispersed in a pre-cooled mixture of 360g of concentrated phosphoric acid and 18g of urea, and stirred at -10℃ for 1.5 hours; 9.6g of chlorosulfonic acid was added, and the reaction was carried out for 3 hours; the precipitate was poured into ice-cold ethanol, centrifuged and washed until neutral, and dispersed to obtain a suspension of sulfonated cellulose nanofibers; 12g of lithium saponite was dispersed in 240g of water, 4.2g of hexadecyltrimethylammonium bromide was added, and the mixture was stirred at 70℃ for 5 hours for modification, and centrifuged and washed to obtain an organic lithium saponite suspension; the two suspensions were mixed at a mass ratio of 2:1, sheared at 10000rpm for 30 minutes, pre-frozen at -50℃ for 5 hours, and freeze-dried to obtain the product. Preparation of pH-responsive nutrient sustained-release gel: 18g humic acid, 12g potassium dihydrogen phosphate, 9.6g potassium nitrate, and 6g ammonium chloride were added to 60g water and stirred at 40℃ for 3 hours. Separately, 9.6g sodium alginate and 4.8g chitosan quaternary ammonium salt were dissolved in 600g water containing 6g glacial acetic acid and stirred overnight. The nutrient complex was added to the premix and mechanically stirred for 1.5 hours. A mixed crosslinking agent solution containing 12g calcium chloride and 6g sodium tripolyphosphate was added dropwise to 600g to form gel beads, which were then matured for 5 hours. After washing, the gel was pre-frozen at -41℃ for 7 hours, freeze-dried at -50℃, and ground to obtain the product. All raw materials were mixed and stirred for 5 minutes, and the mixture was printed using a screw extrusion 3D printer and cured at room temperature for 28 days.

[0081] Comparative Example 1

[0082] The specific implementation method is the same as in Example 1, except that the formula is the same as in Example 1 but no high-strength cross-linked polymer binder is added, and the amount of sulfoaluminate cement is increased to 350g accordingly.

[0083] Comparative Example 2

[0084] The specific implementation method is the same as in Example 1, except that the formula is the same as in Example 1 but no thixotropic rheological property modifier is added, and the amount of metakaolin is increased to 112g accordingly.

[0085] Comparative Example 3

[0086] The specific implementation method is the same as in Example 1, except that the formula is the same as in Example 1 but pH-responsive nutrient slow-release gel is not added, and the amount of KZ particles is increased to 540g accordingly.

[0087] Performance testing

[0088] The 3D-printed plant-based eco-bricks prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following methods:

[0089] All samples were cured for 28 days under standard curing conditions (temperature 20±2°C, relative humidity ≥95%) before testing. Compressive strength testing was performed using a universal testing machine according to GB / T50081, "Standard for Test Methods of Physical and Mechanical Properties of Concrete". The specimen size was 100mm×100mm×100mm cube, the loading rate was 0.6MPa / s, and the average of three specimens was taken. Interlayer bond strength testing used a self-designed interlayer tensile device. A standard printed specimen (200mm×200mm×100mm) was subjected to tensile testing at the interlayer interface, with a loading rate of 0.1MPa / s, and the average of five specimens was taken. Slump flowability testing was performed according to GB / T 2419, "Determination of Flowability of Cement Mortar", using a standard slump cone to measure the diffusion diameter of the slurry on a flat plate. Shape retention testing was performed using a 50mm high column specimen. The initial height was measured immediately, and the final height was measured after 60 minutes of resting. The percentage of height retention was calculated. Porosity testing employed the water saturation method. The specimen was immersed in water for 24 hours, and its saturated surface-dry mass was measured. After drying, its oven-dry mass was measured, and the total porosity was calculated. Nutrient release cycle testing involved immersing the gel-containing specimen in deionized water. The concentrations of nitrogen, phosphorus, and potassium ions in the water were measured daily until 90% of the total nutrient release was achieved. Plant growth experiments used ryegrass as an indicator plant. Seeds were sown on the surface of ecological bricks and cultured in a greenhouse for 60 days. Plant height, biomass, and root length were measured.

[0090] Performance test results:

[0091] Table 1: Performance test results of each embodiment and comparative example

[0092] Group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Compressive strength (MPa) 35.6 32.8 37.2 23.2 30.5 33.8 Interlayer bond strength (MPa) 3.2 2.9 3.4 1.9 2.8 3.1 Slump flowability (mm) 180 175 185 165 155 178 Shape retention rate (%) 98.5 97.8 98.8 95.2 92.3 97.9 Porosity (%) 28.6 29.2 27.9 25.3 26.8 29.5 Nutrient release cycle (days) 85 78 90 - - 25 Plant height (cm) 32.5 30.8 33.6 31.2 30.5 26.8 Biomass (g / plant) 1.25 1.18 1.32 1.15 1.12 0.85 Root length (cm) 25.6 24.3 26.8 23.5 23.8 20.2

[0093] As can be seen from Table 1, Examples 1-3 effectively solved three major technical problems that have long existed in the field of ecological slope protection materials compared with Comparative Examples 1-3. First, in terms of the synergy between mechanical properties and ecological functions, Examples 1-3 introduced a high-strength cross-linked polymer binder to construct an organic-inorganic hybrid network structure, achieving a compressive strength of 32.8-37.2 MPa and an interlayer bonding strength of 2.9-3.4 MPa, which are significantly higher than the 23.2 MPa and 1.9 MPa of Comparative Example 1, proving that the binder effectively enhances the integrity and durability of the material. At the same time, the examples maintained a porosity of 28.6-29.2%, providing the necessary conditions for plant root growth and achieving a unity of mechanical strength and ecological pore structure. Secondly, regarding nutrient supply, the pH-responsive nutrient slow-release gel used in Examples 1-3, through an intelligent controlled-release mechanism, extended the nutrient release cycle to 78-90 days, far exceeding the 25 days of Comparative Example 3. Furthermore, plant height, biomass, and root length were significantly better than in Comparative Example 3, demonstrating that it successfully solved the problems of easy nutrient loss and short-term fertilizer effect associated with traditional methods. Finally, in terms of adaptability to 3D printing processes, Examples 1-3, utilizing a 3D nanonetwork constructed with a thixotropic rheological property modifier, achieved a slump flow of 175-185 mm and a shape retention rate of 97.8-98.8%, significantly better than the 155 mm and 92.3% of Comparative Example 2. This indicates that it effectively improved the extrudability and molding stability of the slurry, solving the problems of easy collapse and deformation during printing. In summary, Examples 1-3, through the synergistic effect of the three modified compounds, achieved the continuous and stable performance of ecological functions while maintaining excellent mechanical properties, and perfectly adapted to the requirements of 3D printing process. They successfully overcame the core technical bottlenecks in the prior art, such as the difficulty in balancing mechanical and ecological performance, low nutrient supply efficiency, and poor printing adaptability.

[0094] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A 3D-printed plant-based eco-brick, characterized in that, Including the following parts by weight of raw materials: Sulfoaluminate cement: 200-350 parts by weight; Metakaolin: 50-150 parts by weight; KZ granules: 400-600 parts by weight; High-strength cross-linked polymer adhesive: 30-80 parts by weight; Thixotropic rheological property modifier: 5-20 parts by weight; pH-responsive nutrient slow-release gel: 20-60 parts by weight; Polycarboxylate superplasticizer: 2-8 parts by weight; Hydroxypropyl methylcellulose: 0.5-2 parts by weight; Water: 150-250 parts by weight; The preparation method of the high-strength cross-linked polymer adhesive includes: A1, purging nitrogen gas into a four-necked flask for purging, then adding deionized water and anhydrous ethanol, stirring and heating to 64-66℃; then adding 2-acrylamido-2-methylpropanesulfonic acid and β-hydroxyethyl methacrylate, stirring until completely dissolved to form a homogeneous solution; then adding ammonium persulfate, maintaining the reaction at 64-66℃ to obtain a prepolymer solution; A2, then first adding anhydrous ethanol solution of tetraethyl orthosilicate, continuing the reaction after the addition is complete, then adding anhydrous ethanol solution of silane coupling agent; after the addition is complete, adjusting the pH of the system to 8.0-8.5 with sodium hydroxide aqueous solution, and continuing the reaction at 64-66℃.

2. The 3D-printed plant-based eco-brick according to claim 1, characterized in that, In step A1, the reaction time is 1-2 hours at 64-66℃.

3. The 3D-printed plant-based eco-brick according to claim 1, characterized in that, In step A2, the reaction continues at 64-66℃ for 3-5 hours.

4. The 3D-printed plant-based eco-brick according to claim 1, characterized in that, The preparation method of the thixotropic rheological property modifier includes: B1, dispersing microcrystalline cellulose in a pre-cooled ionic liquid of concentrated phosphoric acid and urea, and mechanically stirring at -9~-11℃; then adding chlorosulfonic acid to undergo a sulfonation reaction; after the reaction, pouring the mixture into ice-cold ethanol and precipitating it, collecting the precipitate by centrifugation and washing it repeatedly with ethanol until neutral, and finally redispersing it in deionized water, and obtaining a sulfonated cellulose nanofiber suspension by ultrasonic treatment; B2, dispersing lithium saponite in deionized water, adding hexadecyltrimethylammonium bromide, stirring and modifying it in a water bath at 68-72℃, centrifuging and washing it after the reaction, and redispersing it in water to form an organic lithium saponite suspension; finally, mixing the prepared sulfonated cellulose nanofiber suspension with the organic lithium saponite suspension, placing it in a high-speed shear emulsifier, shearing it to form a nanocomposite colloidal dispersion; transferring the nanocomposite colloidal dispersion to a freeze-drying tray, pre-freezing it at -48~-52℃, and then drying it in a freeze dryer.

5. The 3D-printed plant-based eco-brick according to claim 4, characterized in that, In step B1, the mechanical stirring time at -9~-11℃ is 1-2h, and the sulfonation reaction lasts for 2-4h.

6. The 3D-printed plant-based eco-brick according to claim 4, characterized in that, In step B2, the stirring modification time in a water bath at 68-72℃ is 4-6 hours; the pre-freezing time at -48~-52℃ is 4-6 hours.

7. The 3D-printed plant-based eco-brick according to claim 1, characterized in that, The preparation method of the pH-responsive nutrient sustained-release gel includes: C1. Add humic acid, potassium dihydrogen phosphate, potassium nitrate, and ammonium chloride to deionized water and stir at 38-42°C to form a nutrient complex. Then, dissolve sodium alginate and chitosan quaternary ammonium salt in a dilute acid solution containing glacial acetic acid and stir at low speed overnight to form a premix. C2. Then, the nutrient complex slurry is slowly added to the premixed solution and stirred with a mechanical stirrer; then, the mixed slurry is added dropwise to a mixed crosslinking agent solution containing calcium chloride and sodium tripolyphosphate using the electrostatic droplet addition method to form gel beads; after the gel beads have matured in the crosslinking agent solution, they are washed with deionized water. C3. Pre-freeze the gel beads at -40~-42℃, then transfer them to a freeze dryer for freeze drying to constant weight; grind the dried gel beads at low temperature using a ball mill.

8. The 3D-printed plant-based eco-brick according to claim 7, characterized in that, In step C1, the stirring time is 2-4 hours at 38-42℃.

9. The 3D-printed plant-based eco-brick according to claim 7, characterized in that, In step C2, the mechanical stirrer is used for 1-2 hours; the gel beads are matured in the crosslinking agent solution for 4-6 hours.

10. The 3D-printed plant-based eco-brick according to claim 7, characterized in that, In step C3, the pre-freezing time at -40~-42℃ is 6-8 hours, and the freeze-drying temperature is -48~-52℃.