CN-121800453-B - Anti-seepage self-repairing material and preparation method and application thereof

Abstract

The application belongs to the technical field of building materials, and particularly relates to an anti-seepage self-repairing material, and a preparation method and application thereof. The material takes hierarchical porous SiO2 microspheres with surface epoxy groups functionalized as a carrier, and is loaded in a space order, and meanwhile, a hydrophobic dynamic repairing agent and a mineral reinforced precursor are coated. The main chain of the hydrophobic dynamic repairing agent contains dynamic disulfide bonds, has the capability of quick hydrophobic blocking and room temperature self-healing, and the mineral reinforcing precursor can generate secondary C-S-H gel in cracks, so that long-term reinforcement is realized. The epoxy groups on the surface of the carrier and the cement matrix form strong chemical bonding. After the material is mixed with concrete, the self-repairing efficiency and long-term durability of cracks can be remarkably improved, the material is particularly suitable for concrete structures in severe humid environments such as water conservancy and oceans, and the problems that products in the prior repairing technology are poor in durability and interfaces are easy to fall off are solved.

Inventors

• MA HONGYUE
• LIU PEI
• LIU TIANCI
• CAO HEXIAN
• FU ZHENG
• WANG LUYANG
• LIU HAIQING
• LEI ZHIRONG
• Hou chenxing
• MIAO GUOYING
• ZHANG MENG

Assignees

• 铁岭山海环保新材料有限公司

Dates

Publication Date

20260508

Application Date

20260310

Claims (8)

1. 1. The anti-seepage self-repairing material is characterized in that the material is a composite material formed by taking hierarchical porous silica microspheres with surface epoxy groups functionalized as carriers and coating a hydrophobic dynamic repairing agent and a mineral reinforced precursor in a space ordered loading mode; The surface epoxy functionalized hierarchical porous silica microsphere is obtained by carrying out surface grafting modification on hierarchical porous SiO 2 microsphere with bimodal or multimodal pore size distribution through a silane coupling agent, wherein the silane coupling agent is alkoxy silane containing epoxy groups; the hydrophobic dynamic repairing agent is polysiloxane prepolymer with a terminal group containing a hydrolyzable siloxane group and a main chain containing dynamic disulfide bonds; the mineral reinforced precursor is a nano silicon-based active material; the mineral reinforced precursor is silica sol or fumed silica dispersion liquid with the particle size of 10-30 nm; The space ordered loading mode is that firstly, mineral reinforced precursor is loaded in the internal macropores and partial mesopores of the carrier, and then, the hydrophobic dynamic repairing agent is loaded in the surface layer and the residual pore canal of the carrier.
2. 2. The impermeable self-repairing material according to claim 1, wherein the specific surface area of the graded porous SiO 2 microsphere is 300-600m2/g, and the pore size distribution comprises mesopores of 2-10nm and macropores of 20-100 nm.
3. 3. The impermeable self-healing material according to claim 1, wherein the epoxy group-containing alkoxysilane is gamma-glycidoxypropyl trimethoxysilane.
4. 4. The impermeable self-repairing material according to claim 1, wherein the hydrophobic dynamic repairing agent is synthesized by reacting disulfide containing amino group with unsaturated epoxy monomer to synthesize chain extender containing disulfide bond and double bond, and copolymerizing the chain extender with chain transfer agent containing amino group polydimethylsiloxane, mercapto group and methoxy silane through mercapto-ene click reaction.
5. 5. The impermeable self-healing material according to claim 4, wherein the disulfide containing amino group is 4-aminodiphenyl disulfide and the unsaturated epoxy monomer is glycidyl methacrylate.
6. 6. A method of preparing an impermeable self-healing material according to any one of claims 1 to 5, comprising the steps of: S1, preparing hierarchical porous SiO 2 microspheres, namely adding a structure directing agent into an alcohol-water-ammonia mixed solution, uniformly stirring, then dropwise adding tetraethoxysilane, and centrifuging, washing, drying and calcining after reaction to obtain hierarchical porous SiO 2 microspheres; S2, surface epoxy group functionalization, namely reacting the microsphere obtained in the step S1 with hydrolyzed epoxy group-containing silane coupling agent solution, centrifuging, washing and drying to obtain a hierarchical porous SiO 2 microsphere with the surface epoxy group functionalization; S3, synthesizing a hydrophobic dynamic repairing agent, namely synthesizing a chain extender containing disulfide bonds, and reacting the chain extender with amino-terminated polydimethylsiloxane, a chain transfer agent containing sulfhydryl and methoxysilane to obtain a hydrophobic dynamic repairing agent prepolymer; s4, assembling the composite self-repairing material, namely sequentially dipping the functionalized microspheres obtained in the step S2 in nano silica sol and the repairing agent prepolymer solution obtained in the step S3 under a vacuum condition, and performing rotary evaporation and drying after each dipping to obtain a final product.
7. 7. The preparation method according to claim 6, wherein the structure directing agent in the step S1 is cetyl trimethyl ammonium bromide, the calcination temperature is 500-600 ℃, the reaction condition in the step S2 is 60-80 ℃ reflux for 6-10 hours, the temperature of the two rotary evaporation in the step S4 is 40-50 ℃ and 35-45 ℃ respectively, and the rotation speed is 40-60rpm and 20-40rpm respectively.
8. 8. Use of an impermeable self-healing material according to any of claims 1 to 5, for concrete, in an amount of 1.0% to 3.0% of the total mass of the concrete binder.

Description

Anti-seepage self-repairing material and preparation method and application thereof Technical Field The application belongs to the technical field of building materials, and particularly relates to an anti-seepage self-repairing material, and a preparation method and application thereof. Background Concrete is the most important building material in hydraulic engineering, and crack control and seepage-proof durability are core problems related to building safety and service life. Under the coupling action of complex stress and environmental corrosion, the traditional concrete is easy to generate microcracks, the microcracks become channels for invasion of water and harmful ions, accelerated degradation of reinforcement corrosion, freeze thawing damage, sulfate corrosion and the like is caused, and the repairing is extremely difficult and high in cost. To solve this problem, self-repairing concrete technology has been developed. The prior art mainly comprises (1) microcapsule technology, namely, encapsulating a repairing agent in a brittle shell, and releasing the repairing agent to realize repairing when cracks are expanded. However, the repairing agent has the problems of poor compatibility with an alkaline matrix, one-time repairing, insensitivity to microcracks and the like. (2) Microorganism mineralization technology, namely, calcium carbonate sediment is generated by utilizing bacterial induction to seal cracks. But the challenges of low survival rate of bacteria in high-alkaline environment, slow repair rate, possibility of long-term environmental influence caused by nutrient sources and the like are faced. (3) And penetrating the crystalline waterproof material to form insoluble crystal in the pores to block the passage. The reaction is not controllable and the ability to repair the formed macro-cracks is limited. The common defects of the prior art are that the repairing behavior is mostly passive and disposable, the repairing product and the concrete matrix are mostly physically filled, and the risks of unmatched thermal expansion coefficients, weak chemical bonding, easy falling off or secondary cracking under long-term service exist, namely the long-term durability and the matrix compatibility of the repairing product are poor. To improve the long-term efficacy of repair, researchers have attempted to optimize the chemical composition of the repair agent or to employ cascade repair. For example, silane-based waterproofing agents are used to increase hydrophobicity or pozzolanic reactions incorporating nano-SiO 2 produce secondary calcium silicate hydrate (C-S-H) gels. However, these methods fail to fundamentally solve the problems of stress concentration and performance degradation of the repair interface under dynamic environmental stress, and the repair body itself lacks the ability to adapt and heal the damage. Therefore, development of a novel anti-seepage self-repairing material is needed, which not only has the cascade repairing capability of quick plugging and long-term reinforcement, but also can realize self-adaption and long-term stability of a repairing product by introducing dynamic interface chemistry, thereby fundamentally overcoming the defects of the prior art. Disclosure of Invention The application aims at providing an anti-seepage self-repairing material, a preparation method and application thereof, wherein the material can realize ordered cascade repairing from hydrophobic rapid plugging to mineral reinforcement strengthening of concrete cracks, and a repairing product can form strong chemical bonding with a matrix and has dynamic self-healing capacity, so that excellent long-term anti-seepage durability is obtained. The application also aims to provide a preparation method of the anti-seepage self-repairing material, which has controllable process and easy scale, and can accurately assemble repairing components with different functions into a multifunctional carrier. In order to achieve the above purpose, the application adopts the following technical scheme: the application provides an anti-seepage self-repairing material which is characterized in that the anti-seepage self-repairing material is a composite material which is formed by taking surface functionalized hierarchical porous silica microspheres as a carrier, carrying out ordered loading through space and coating a hydrophobic dynamic repairing agent and a mineral reinforced precursor. The surface functionalized hierarchical porous silica microsphere is prepared by combining a sol-gel method and a template method, is provided with a SiO 2 microsphere with bimodal or multimodal pore size distribution, and is subjected to grafting modification on the surface by using a silane coupling agent (preferably epoxy group-containing gamma-glycidoxypropyl trimethoxysilane, GPTMS) to enable the surface to be rich in active epoxy groups. The support was named EHP-SiO 2. The hydrophobic dynamic repairing agent is polysiloxane pre