Self-healing material as well as preparation method and application thereof
By using a core-shell structure design and a self-healing material with synergistic component effects, the problem of premature reaction of penetrating crystalline self-healing materials in coastal environments has been solved, achieving long-term self-healing and improved durability of concrete structures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA WEST CONSTR ACAD OF BUILDING MATERIALS CO LTD
- Filing Date
- 2025-12-23
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional penetrating crystalline self-healing materials are prone to premature reaction in coastal environments, affecting their healing performance and failing to effectively improve the long-term durability of concrete structures.
The core-shell structure design includes a core layer containing a penetrating crystallization self-healing component and a shell layer coated with a nonionic surfactant. The synergistic effect of porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, and lithium-containing compounds promotes crack healing, and the slow-release control of the self-healing component is achieved through the nonionic surfactant.
It significantly improves the efficiency and chloride ion penetration resistance of self-healing materials, extends the self-healing reaction time, and enhances the durability of concrete structures in coastal environments.
Smart Images
Figure CN122010455A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of building materials technology, specifically relating to a self-healing material, its preparation method, and its application. Background Technology
[0002] Compared to inland environments, coastal environments experience additional long-term corrosion, making traditional cement concrete highly susceptible to premature degradation and damage. To ensure the long-term stability and safety of concrete structures in coastal environments, existing technologies employ a series of improvements and material optimizations, including concrete mix design optimization, concrete surface protection, electrochemical protection systems, and the addition of self-healing materials. Among these, self-healing materials represent the most promising approach.
[0003] Self-healing materials mainly include different types such as penetrating crystallization and microbial mineralization. Among them, penetrating crystallization is the most widely used type due to its low cost and ease of industrial production. However, penetrating crystallization self-healing materials usually have high reactivity with water, and premature reaction can affect their healing performance. Summary of the Invention
[0004] The purpose of this invention is to provide a self-healing material, its preparation method, and its application. This self-healing material has a core-shell structure in which a nonionic surfactant-coated, penetrating, crystalline self-healing component is formed. It is particularly suitable for the long-term self-healing and durability improvement of concrete cracks in coastal environments, thus ensuring the long-term durability of concrete structures.
[0005] Specifically, the present invention provides the following technical solutions: A self-healing material, which is a particle with a core-shell structure, wherein the core layer contains a penetrating crystallizing self-healing component and the shell layer contains a nonionic surfactant. The penetrating crystallization self-healing component comprises porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds.
[0006] The core-shell structured self-healing material provided by this invention comprises a core-layer infiltration crystallization self-healing component composed of porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds. Specifically, the presence of nano-alumina in the porous calcium silicate loaded with nano-alumina enhances the interfacial bonding between the self-healing material and the cement matrix. Simultaneously, the porous calcium silicate structure provides a pathway for water penetration, promoting crack filling and healing. Nano-zirconia provides a nucleation site for hydration products, promoting crystal growth at crack sites; secondly, its high hardness and chemical stability improve the impermeability of the healing products. The calcium-containing compounds and other silicate compounds release calcium ions when cracks occur. The lithium-containing compounds release lithium ions, promoting the formation of hydrated calcium silicate (CSH) from calcium hydroxide and siliceous materials at crack sites, shortening the reaction time of the self-healing products, and simultaneously forming insoluble lithium silicate, further densifying the structure. There is also a synergistic effect among the components: on the one hand, direct incorporation of nanomaterials results in high activity and early reaction, leading to a decrease in efficiency. Using porous calcium silicate as a carrier achieves secondary protection; calcium, silicon, and lithium compounds can react to form crystals. Simultaneously, nano-zirconia and the porous calcium silicate framework can act as "micro-aggregates" filling the gel network, increasing density. This penetrating crystallization self-healing component, by coordinating the properties of different materials and optimizing the proportions, allows each component to complement each other, significantly improving the material's self-healing efficiency and resistance to chloride ion penetration. The shell layer uses a nonionic surfactant, which enables controlled release of the penetrating crystallization self-healing components.
[0007] Preferably, the mass ratio of the porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds and other silicate compounds is 1:0.1~0.4:1~3:1~5:1~3.
[0008] Preferably, the porous calcium silicate loaded with nano-alumina meets the following conditions: the specific surface area of the porous calcium silicate is >200 m² / g; the pore size distribution of the porous calcium silicate is 15-25% micropores (0.5-2 nm) and 75-85% mesopores (2-50 nm); the nano-alumina loading is 5-15% of the mass of the porous calcium silicate. If the specific surface area is too small or the pore size distribution is too low, it will be detrimental to the loading process.
[0009] Preferably, the nano-zirconia is tetragonal zirconia (3Y-ZrO2) with a particle size of 40-80 nm and a Mohs hardness ≥9.0; And / or, the calcium-containing compound is one or more of calcium aminosulfonate, calcium stearate, and calcium polyphosphate; And / or, the lithium-containing compound is one or more of lithium carbonate and lithium sulfate; And / or, the other silicate compounds are one or more of sodium silicate, sodium metasilicate, aluminum silicate, and magnesium silicate.
[0010] Preferably, the nonionic surfactant is one or more of polyethylene glycol and its derivatives, coconut oil fatty acid monoethanolamide, EO-PO block copolymers, and alcohol ethoxylates.
[0011] Preferably, the particle size of the self-healing material is less than 0.6 mm; the mass ratio of the core layer to the shell layer is 70:30 to 90:10.
[0012] The present invention also provides a method for preparing the above-mentioned self-healing material, comprising the following steps: (a) Porous calcium silicate was impregnated and mixed with aluminum solution, dried and then heated to decompose, to obtain porous calcium silicate loaded with nano-alumina; (b) Porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds and other silicate compounds are dry-mixed in a granulator and coated with liquid nonionic surfactant to form core-shell particles; (c) The core-shell particles are cured by hot air at 40-60℃ for a period of time, and then sieved to obtain a self-healing material with a particle size of less than 0.6 mm.
[0013] Preferably, in step (a), the aluminum solution is a 0.5 mol / L Al2(SO4)3 aqueous solution, and the immersion time is more than 12 hours.
[0014] The present invention also provides a concrete, the raw materials of which include cementitious materials and the above-mentioned self-healing materials; The amount of the self-healing material used is 1-2 wt% based on the mass of the cementitious material.
[0015] The present invention also provides the application of the above-mentioned concrete in coastal environments, marine environments, and underground environments containing chloride salts.
[0016] The beneficial effects of this invention are at least as follows: (1) The self-healing material provided by the present invention adopts a core-shell structure design. The core is rich in penetrating crystallization active components, and the shell is coated with non-ionic surfactants, which effectively realizes the slow release control of self-healing components; (2) The self-healing material provided by the present invention has a high specific surface area of loaded nano-alumina porous calcium silicate, tetragonal phase nano-zirconia and composite calcium / lithium / silicon components in the core layer, which work synergistically to significantly improve the self-healing efficiency and resistance to chloride ion penetration of the material. (3) The self-healing material provided by the present invention has a simple and environmentally friendly preparation process and is applicable to various cement-based structural materials, especially suitable for long-term self-healing and durability improvement of concrete cracks in coastal environments. Attached Figure Description
[0017] Figure 1 The image shows the crack healing process of concrete prepared using the additive from Example 1 after 14 days of underwater curing in Experimental Example 2. Figure 2 This is an electron microscope image of concrete prepared using the additive from Example 1 in Experiment 2 after being cured in water for 14 days. Figure 3 The image shows cracks in the concrete of the baseline group in Experiment Example 2 after 14 days of underwater curing. Detailed Implementation
[0018] 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 are described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art, or in accordance with the product manual.
[0019] In the following examples, the porous calcium silicate used was prepared by a modified existing hydrothermal method: calcium acetate and sodium silicate were hydrothermally reacted at 120°C for 2 hours with a calcium-to-silicon molar ratio of 1:1, PEG as a pore-forming agent, and water. The mixture was then dried and redispersed. BET analysis showed that the specific surface area of the porous calcium silicate was 240 m² / g; the pore size distribution was 20% micropores (0.5-2 nm) and 80% mesopores (2-50 nm). The nano-zirconia used is tetragonal zirconia (3Y-ZrO2) with a particle size of 40-80 nm and a Mohs hardness ≥9.0; The calcium-containing compound used is calcium aminosulfonate; The lithium-containing compound used is lithium carbonate; The other silicate compound used is sodium silicate; The nonionic surfactant used is polyethylene glycol 20000.
[0020] Example 1 A self-healing material, which is a particle with a core-shell structure, wherein the core layer is a penetrating crystallization self-healing component and the shell layer is a nonionic surfactant; The penetrating crystallization self-healing component consists of porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds.
[0021] The preparation method is as follows: (a) Core layer preparation: Porous calcium silicate was impregnated and mixed with 0.5 mol / L Al2(SO4)3 aqueous solution for more than 12 h, dried at 60℃, and then thermally decomposed at 900℃ for 2 h to form porous calcium silicate powder loaded with nano-alumina, wherein the nano-alumina loading was 10% of the mass of porous calcium silicate; (b) Core-shell coating: The loaded nano-alumina porous calcium silicate powder obtained in step a, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds are dry-mixed in a granulator in a mass ratio of 1:0.2:2:2:2 to obtain a penetrating crystallization self-healing component. Then, a liquid nonionic surfactant is sprayed in to adhere and coat the component, forming core-shell particles. The mass ratio of the penetrating crystallization self-healing component to the nonionic surfactant is 9:1. (c) Post-treatment: Curing with hot air at 40-60℃ for 2 hours, and then sieving while cooling to obtain self-healing material with a particle size of less than 0.6mm.
[0022] Example 2 Compared with Example 1, the only difference is that the core layer infiltration crystallization self-healing component is composed of porous calcium silicate loaded with nano-alumina, calcium-containing compounds, lithium-containing compounds and other silicate compounds in a mass ratio of 1:2:2:2, and does not contain nano-zirconia.
[0023] Example 3 Compared with Example [1]1, the only difference is that the core layer penetration crystallization self-healing component is composed of porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compound and lithium-containing compound in a mass ratio of 1:0.2:2:2, and does not contain other silicate compounds.
[0024] Example 4 The only difference from Example 1 is that the surface coating material is sliced paraffin.
[0025] Comparative Example 1 Compared with Example 1, the only difference is that the porous calcium silicate loaded with nano-alumina in the raw material is replaced with porous calcium silicate, and step (a) is omitted in the preparation method.
[0026] Experimental Example 1 Concrete was prepared using the additives of Examples 1-3, with the following formula: 340 kg of low-carbon cement, 910 kg of fine aggregate, 1020 kg of coarse aggregate, 140 kg of water, and the self-healing material. The low-carbon cement was prepared from high-content iron tailings powder. The amount of self-healing material added was 2 wt% based on the mass of the low-carbon cement.
[0027] Concrete was prepared in batches, with two sets numbered. One set was normally formed and numbered PT. The other set had 0.3mm aluminum sheets embedded in it. After initial setting, the aluminum sheets were removed, and artificial cracks were created. This set was numbered YH. The normal set was cured for 28 days and then tested for the first and second impermeability pressure according to standards. The cracked set was cured for 14 days and then placed in water and seawater for 28 days, after which its impermeability was tested according to standards.
[0028] The performance test results are shown in Table 1 (pressure unit is MPa), where the baseline group is concrete without added self-healing material.
[0029] Table 1. Concrete performance test results
[0030] Experimental Example 2 Concrete was prepared using the additive from Example 1, with the following formula: 340 kg of low-carbon cement, 910 kg of fine aggregate, 140 kg of water, and the self-healing material. The low-carbon cement was prepared from high-content iron tailings powder. The amount of self-healing material added was 2 wt% based on the mass of the low-carbon cement. The baseline group was concrete without the addition of self-healing material.
[0031] Concrete prepared using the additive in Example 1 and concrete from the reference group were cured for 28 days before being broken and cracked. They were then fixed in place with a membrane and cured in water for 14 days. The results are as follows: Figure 1-3 As shown, the concrete prepared with the additive of Example 1 achieved self-healing of cracks, while the concrete in the baseline group still had cracks. Furthermore, the concrete cured in water for 14 days was subjected to a fracture test using a 500g weight; the concrete prepared with the additive of Example 1 did not fracture.
[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A self-healing material, characterized in that, It consists of particles with a core-shell structure, the core layer containing a penetrating crystallization self-healing component, and the shell layer containing a nonionic surfactant; The penetrating crystallization self-healing component comprises porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds.
2. The self-healing material according to claim 1, characterized in that, The mass ratio of the porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds and other silicate compounds is 1:0.1~0.4:1~3:1~5:1~3.
3. A self-healing material according to claim 1 or 2, characterized in that, The porous calcium silicate loaded with nano-alumina satisfies the following conditions: the specific surface area of the porous calcium silicate is >200 m² / g; the pore size distribution of the porous calcium silicate is 15-25% micropores (0.5-2 nm) and 75-85% mesopores (2-50 nm); the nano-alumina loading is 5-15% of the mass of the porous calcium silicate.
4. A self-healing material according to claim 1 or 2, characterized in that, The nano-zirconia is tetragonal zirconia with a particle size of 40-80 nm and a Mohs hardness ≥9.0; And / or, the calcium-containing compound is one or more of calcium aminosulfonate, calcium stearate, and calcium polyphosphate; And / or, the lithium-containing compound is one or more of lithium carbonate and lithium sulfate; And / or, the other silicate compounds are one or more of sodium silicate, sodium metasilicate, aluminum silicate, and magnesium silicate.
5. A self-healing material according to claim 1 or 2, characterized in that, The nonionic surfactant is one or more of polyethylene glycol and its derivatives, coconut oil fatty acid monoethanolamide, EO-PO block copolymers, and alcohol ethoxylates.
6. A self-healing material according to claim 1 or 2, characterized in that, The particle size of the self-healing material is less than 0.6 mm; the mass ratio of the core layer to the shell layer is 70:30 to 90:
10.
7. A method for preparing the self-healing material according to any one of claims 1-6, comprising the following steps: (a) Porous calcium silicate was impregnated and mixed with aluminum solution, dried and then heated to decompose, to obtain porous calcium silicate loaded with nano-alumina; (b) Porous calcium silicate loaded with nano-alumina, nano-zirconia, calcium-containing compounds, lithium-containing compounds and other silicate compounds are dry-mixed in a granulator and coated with liquid nonionic surfactant to form core-shell particles; (c) The core-shell particles are cured by hot air at 40-60℃ for a period of time, and then sieved to obtain a self-healing material with a particle size of less than 0.6 mm.
8. The preparation method according to claim 7, characterized in that, In step (a), the aluminum solution is a 0.5 mol / L Al2(SO4)3 aqueous solution, and the immersion time is more than 12 h.
9. A type of concrete, characterized in that, The raw materials include cementing materials and the self-healing materials according to any one of claims 1-6; The amount of the self-healing material used is 1-2 wt% based on the mass of the cementitious material.
10. The application of the concrete according to claim 9 in coastal environments, marine environments, and underground environments containing chloride salts.