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CN-122010455-A - Self-healing material and preparation method and application thereof

CN122010455ACN 122010455 ACN122010455 ACN 122010455ACN-122010455-A

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a self-healing material and a preparation method and application thereof. The self-healing material is a particle with a core-shell structure, wherein a core layer comprises a penetrating and crystallizing self-healing component, a shell layer comprises a nonionic surfactant, and the penetrating and crystallizing self-healing component comprises porous calcium silicate loaded with nano alumina, nano zirconia, a calcium-containing compound, a lithium-containing compound and other silicate compounds. The shell layer of the self-healing material adopts a nonionic surfactant, so that the slow release control of the self-healing component is effectively realized, the high specific surface area of the core layer is loaded with the synergistic effect of nano alumina porous calcium silicate, tetragonal phase nano zirconia and the composite calcium/lithium/silicon-containing component, the self-healing efficiency and the chloride ion permeation resistance of the material are obviously improved, and the self-healing material is particularly suitable for the long-term self-healing and the durability improvement of concrete cracks in a coastal environment.

Inventors

  • GAO YUXIN
  • LIU MING
  • YAN SONGLING
  • ZENG CHAO
  • YE ZI
  • JIN ZIHAO
  • HAN WENJIN
  • ZHANG RUI

Assignees

  • 中建西部建设建材科学研究院有限公司

Dates

Publication Date
20260512
Application Date
20251223

Claims (10)

  1. 1. The self-healing material is characterized in that the self-healing material is particles with a core-shell structure, a core layer comprises an osmotic crystallization self-healing component, and a shell layer comprises a nonionic surfactant; The osmotically crystallized self-healing component comprises nano-alumina loaded porous calcium silicate, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds.
  2. 2. The self-healing material according to claim 1, wherein the mass ratio of the porous calcium silicate loaded with nano aluminum oxide, the nano zirconium oxide, the calcium-containing compound, the lithium-containing compound and the other silicate compounds is 1:0.1-0.4:1-3:1-5:1-3.
  3. 3. A self-healing material according to claim 1 or 2, wherein the porous calcium silicate loaded with nano alumina satisfies the following conditions that the specific surface area of the porous calcium silicate is >200 m2/g, the pore size distribution of the porous calcium silicate is that micropores (0.5-2 nm) account for 15-25%, mesopores (2-50 nm) account for 75-85%, and the nano alumina load is 5-15% of the mass of the porous calcium silicate.
  4. 4. The self-healing material according to claim 1 or 2, wherein the nano zirconia is tetragonal zirconia, the grain size is 40-80 nm, and the mohs hardness is more than or equal to 9.0; and/or the calcium-containing compound is one or more of calcium sulfamate, 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. 5. A self-healing material according to claim 1 or 2, wherein the nonionic surfactant is one or more of polyethylene glycol and derivatives thereof, coconut fatty acid monoethanolamide, EO-PO block copolymers, alcohol ethoxylates.
  6. 6. The self-healing material according to claim 1 or 2, wherein the particle size of the self-healing material is less than 0.6mm, and the mass ratio of the core layer to the shell layer is 70:30-90:10.
  7. 7. A method of preparing the self-healing material according to any one of claims 1 to 6, comprising the steps of: (a) Soaking and mixing porous calcium silicate with aluminum solution, drying and then heating for decomposition to obtain porous calcium silicate loaded with nano aluminum oxide; (b) Dry mixing porous calcium silicate loaded with nano aluminum oxide, nano zirconium oxide, a calcium-containing compound, a lithium-containing compound and other silicate compounds in a granulator, spraying a liquid nonionic surfactant, and adhering and coating to form core-shell particles; (c) And (3) curing the core-shell particles with hot air at 40-60 ℃ for a period of time, and sieving to obtain the self-healing material with the particle size of less than 0.6 mm.
  8. 8. The method according to claim 7, wherein in the step (a), the aluminum solution is an aqueous solution of 0.5 mol/L of Al 2 (SO 4 ) 3 , and the dipping time is 12 to h.
  9. 9. A concrete characterized in that the raw materials comprise a cementitious material and the self-healing material according to any one of claims 1 to 6; the self-healing material is used in an amount of 1-2wt% based on the mass of the cementing material.
  10. 10. Use of the concrete of claim 9 in a coastal environment, a marine environment, a chlorine salt-containing underground environment.

Description

Self-healing material and preparation method and application thereof Technical Field The invention belongs to the technical field of building materials, and particularly relates to a self-healing material and a preparation method and application thereof. Background The coastal environment is additionally subjected to long-term corrosion compared with the inland environment, so that the conventional cement concrete is extremely prone to premature degradation and damage under the coastal environment. To ensure long-term stability and safety of concrete structures in a coastal environment, the prior art adopts a series of technical improvements and material optimizations including optimization of concrete mix ratio, protection of concrete surfaces, electrochemical protection systems, addition of self-healing materials, etc., wherein the self-healing materials are the most potential directions. The self-healing material mainly comprises different types of osmotic crystallization, microbial mineralization and the like, wherein the osmotic crystallization is the most widely used type at present due to low manufacturing cost and easy industrial production. However, osmotically crystalline self-healing materials generally have a high reactivity with water and react prematurely to affect healing performance. Disclosure of Invention The invention aims to provide a self-healing material, a preparation method and application thereof, wherein the self-healing material is a core-shell structure of a non-ionic surfactant coated permeable crystallization self-healing component, is particularly suitable for long-term self-healing and durability improvement of concrete cracks in a coastal environment, and provides a guarantee for long-term durability of the concrete structure. Specifically, the invention provides the following technical scheme: a self-healing material which is a particle having a core-shell structure, a core layer comprising an osmotically crystallized self-healing component, a shell layer comprising a nonionic surfactant; The osmotically crystallized self-healing component comprises nano-alumina loaded porous calcium silicate, nano-zirconia, calcium-containing compounds, lithium-containing compounds, and other silicate compounds. The core-shell structure self-healing material provided by the invention is characterized in that the core-layer permeation crystallization self-healing component is formed by compounding porous calcium silicate loaded with nano alumina, nano zirconia, a calcium-containing compound, a lithium-containing compound and other silicate compounds. The porous calcium silicate structure provides a path for water penetration to promote crack filling and healing, the nano zirconia provides a nucleation base for hydration products on one hand to promote crystal growth at cracks, and the nano zirconia has high hardness and stable chemical property to improve the impermeability of the healed products, calcium-containing compounds and other silicate compounds can release calcium ions when the cracks are generated, and the lithium-containing compounds release lithium ions to promote calcium hydroxide and siliceous materials to generate calcium silicate hydrate (C-S-H) at the cracks, so that the reaction time of the self-healing products is shortened, insoluble lithium silicate is formed, and the structure is further densified. On the one hand, the nanometer material has high activity, early reaction and reduced efficiency, and the porous calcium silicate is used as carrier to realize the secondary protection, and the calcium, silicon and lithium compound can react to form crystal, and the nanometer zirconia and porous calcium silicate skeleton may be used as micro aggregate to fill in gel network to raise compactness. The osmotic crystallization self-healing component optimizes the mixing ratio by coordinating the characteristics of different materials, and each component has an advantage complementary effect, so that the self-healing efficiency and the chloride ion permeation resistance of the material are obviously improved; The shell layer adopts nonionic surfactant, and can realize slow release control of the osmotic crystallization self-healing component. Preferably, the mass ratio of the porous calcium silicate loaded with nano aluminum oxide, the nano zirconium oxide, the calcium-containing compound, the lithium-containing compound and other silicate compounds is 1:0.1-0.4:1-3:1-5:1-3. Preferably, the porous calcium silicate loaded with nano aluminum oxide meets the following conditions that the specific surface area of the porous calcium silicate is more than 200m <2 >/g, the pore size distribution of the porous calcium silicate is that micropores (0.5-2 nm) account for 15-25%, mesopores (2-50 nm) account for 75-85%, and the nano aluminum oxide loading is 5-15% of the mass of the porous calcium silicate. Too small a specific surface area or too low a pore size distribution is detrimental