Rust inhibitor for marine reinforced concrete and preparation method thereof

Abstract

The invention discloses a corrosion inhibitor for marine reinforced concrete and a preparation method, and relates to the technical field of corrosion inhibitors. The corrosion inhibitor is double-layer wall shell nanometer micro-capsule powder, the average particle size is 50-100 microns, a core phase comprises an inorganic corrosion inhibitor, an organic film-forming agent, a pH adjusting and mineralizing component and / or sacrificial anode particles, and a shell phase is composed of an inner layer shell, an outer layer shell and a nanometer additive. The corrosion inhibitor realizes triple protection in concrete through physical barrier, electrochemical stability and nano-structure self-adaptive response, and can be coated on the surface of a steel bar to form a temporary protection film in a construction period. W / O / W double emulsification, shell layer curing and spray drying processes are adopted for preparation, so that controllable release and stable components are ensured. In application, continuous protection from the construction period to the whole life cycle can be achieved, and the durability and chloride ion corrosion resistance of marine reinforced concrete are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of rust inhibitor technology, specifically to a rust inhibitor for marine reinforced concrete and its preparation method. Background Technology

[0002] Existing marine reinforced concrete structures typically employ direct addition of corrosion inhibitors or coatings on the steel reinforcement surface for corrosion protection. Common corrosion inhibitors are single inorganic salts (such as nitrites and phosphates) or organic film-forming agents, which can form a passivation film on the steel reinforcement surface after incorporation. However, these corrosion inhibitors have the following drawbacks: early depletion and late-stage failure: Single-component corrosion inhibitors are rapidly released and react with the medium in the highly alkaline environment of concrete, resulting in insufficient effective components in the later stages of service, making them unable to cope with the continuous intrusion of chloride ions. Lack of on-demand response capability: The release rate of existing corrosion inhibitors is uncontrollable, and they cannot be precisely released when corrosion trigger signals appear, easily resulting in insufficient response in the early stages of corrosion, while having no effective components left at the peak of corrosion. Single-mechanism protection: Most protection schemes rely solely on physical coating barriers or chemical corrosion inhibition, failing to achieve the synergistic effect of physical barriers, electrochemical stability, and intelligent adaptive response. Protection gap during construction: During the stage from binding to pouring, steel reinforcement is exposed to the marine atmosphere, and traditional internal corrosion inhibitors cannot provide effective protection during this stage, resulting in a high risk of early corrosion. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides the following technical solution: a rust inhibitor for marine reinforced concrete, wherein the rust inhibitor is a double-walled shell nanocapsule powder, the double-walled shell nanocapsule comprising a core phase and an outer shell phase, the outer shell phase comprising an inner shell and an outer shell; wherein: the core phase, by mass, comprises at least one of inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjusting and mineralizing components, and / or sacrificial anode particles; the outer shell phase, by mass, comprises an inner shell, an outer shell, and nano-additives; the average particle size of the double-walled shell nanocapsule is 50–100 μm; the rust inhibitor is used to provide triple protection of physical barrier, electrochemical stability, and nanostructure self-adaptation in marine reinforced concrete.

[0004] Preferably, the inner shell is selected from one of modified epoxy resin, polylactic acid (PLA), and polymethyl methacrylate (PMMA); the outer shell is selected from one of alginate / calcium, polyvinyl alcohol (PVA), and chitosan; and the nano-additive is selected from one or more of nano-SiO2, layered double hydroxide (LDH), and graphene oxide (GO).

[0005] Preferably, the inorganic corrosion inhibitor is selected from one or more of nitrite, phosphate, and molybdate; the organic corrosion inhibitor and film-forming component is selected from one or more of tannic acid, phytic acid, sebacic acid, and palmitamine; the pH adjusting and mineralizing component is selected from one or more of calcium hydroxide microcrystals, magnesia, and calcium phosphate precursors; and the sacrificial anode particles are selected from one or more of nano-zinc and nano-magnesium. Sacrificial anode particles refer to nanoscale metal particles encapsulated in the core phase, used to act as micro-sacrificial anodes around the reinforcing steel, preferentially corroded to protect the steel; morphology and location: the particles are tens to hundreds of nanometers in size, initially encapsulated in the core phase by double-walled nanocapsules; when triggering conditions occur (pH decrease, Cl...),... - When the temperature rises (or cracks are under stress), the microcapsules release the material as needed to the vicinity of the steel-concrete interface. The particles and steel reinforcement form a microcouple in the concrete pore fluid; the sacrificial anode particles corrode first, pushing the steel reinforcement to the cathode side, thus protecting it; their corrosion products (such as Zn(OH)₂, ZnO, Mg(OH)₂) deposit at the interface to form a film / fill the pores, acting as a secondary physical barrier, increasing local alkalinity, and inhibiting corrosion propagation; synergistically with nano-additives such as layered bimetallic hydroxide (LDH): LDH captures Cl₂... - It also releases passivating anions to stabilize the passivation environment of the steel reinforcement. In this way, nano-sizing results in a milder reaction, more uniform dispersion, and a larger effective area; microcapsules avoid excessively rapid reactions in the early stages of mixing (especially since nano-magnesium is prone to over-reaction in strong alkaline aqueous solutions), and postpone the release until it is truly needed, thus balancing safety and long-term effectiveness.

[0006] Preferably, the core phase formulation range (based on core phase mass) is: 10–60 wt% inorganic corrosion inhibitor, 2–20 wt% organic corrosion inhibitor and film-forming component, 10–50 wt% pH adjustment and mineralization component, and 1–10 wt% sacrificial anode particles; the outer shell phase formulation range (based on outer shell mass) is: 5–25 wt% inner shell, 5–15 wt% outer shell, and 0.1–5 wt% nano-additives.

[0007] Preferably, the outer shell swells or partially dissolves in a high-alkali / high-salt / high-humidity environment to achieve early release, while the inner shell provides slow release and long-lasting protection. When the pH of the concrete decreases, the chloride ion concentration increases, or cracks are stressed, the double-walled shell nanocapsules accelerate the release of the core phase as needed, thereby forming a biomimetic sealing and repassivation at the steel-concrete interface.

[0008] Preferably, the nano-additive comprises a layered bimetallic hydroxide (LDH), which is capable of capturing Cl. - And release passivating anions (NO2) - or CO3 2-Electrochemical stabilization is achieved in synergy with the inorganic corrosion inhibitors of the core phase.

[0009] Preferably, the rust inhibitor can be mixed with water to form a coating slurry, which is applied to the surface of steel bars or concrete to form an early temporary protective film. The early temporary protective film is formed by an outer shell and organic corrosion inhibitors and film-forming components. It self-dissolves in the later stages of service and does not affect the concrete matrix.

[0010] A method for preparing a rust inhibitor for marine reinforced concrete includes a double emulsification step: A core aqueous phase containing inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjusting and mineralizing components, and / or sacrificial anode particles is subjected to W / O primary emulsification with an inner shell organic phase, followed by W / O / W secondary emulsification with an outer shell aqueous phase. W / O: Water-in-oil emulsion, dispersing the aqueous phase (core aqueous phase containing corrosion inhibitors / mineralizing solutes) into numerous small water droplets suspended in the oil phase (inner shell organic phase), a continuous phase. W / O / W: Water / oil / water dual emulsion (secondary emulsification), first obtaining the above W / O droplets, then further dispersing these water-in-oil droplets as dispersion units into the outer shell aqueous phase, thus forming a double-layer structure of water droplets → oil layer → outer aqueous phase. First, W / O: The functional components (inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjusters and mineralizers, sacrificial anode particles) from the core aqueous phase are encapsulated in the organic phase of the inner shell, laying the foundation for the formation of the inner shell. Then, W / O / W: These W / O droplets are dispersed into the aqueous phase of the outer shell, thus simultaneously forming a double-layered shell structure: an inner shell (oil phase solidification) + an outer shell (aqueous phase cross-linking). Shell formation steps: The organic phase solvent of the inner shell is volatilized to solidify the inner shell, and then... (The sentence is incomplete and requires further context to translate accurately.) 2+ Cross-linked and cured outer shell; spray drying step: The stable bilayer emulsion is spray-dried to obtain bilayer shell nanocapsule powder with an average particle size of 50–100 μm. The rust inhibitor is added to the marine reinforced concrete mixture at 1.0–3.0 wt% of the cementitious material mass, so that the bilayer shell nanocapsules provide triple protection of physical barrier, electrochemical stabilization and nanostructure self-adaptation throughout the service life of the concrete.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The rust inhibitor of the present invention integrates three mechanisms: physical barrier, electrochemical stability and nanostructure self-adaptation, to achieve phased protection throughout the service life of concrete. In the early stage, the outer shell and organic corrosion inhibitor form a dense film to block the penetration of seawater and chloride salts. In the middle and late stages, the core corrosion inhibitor is gradually released to maintain the passivation state of the steel reinforcement, and the protective components are released quickly when the corrosion trigger signal appears. This multi-stage, trigger-type protection significantly extends the service life of marine reinforced concrete structures; (2) The outer shell of the rust inhibitor of the present invention can be controlled to swell or partially dissolve in high-alkali, high-salt and high-humidity environments to achieve early protection; while the inner shell ensures long-term slow release. Especially when corrosion precursors such as increased chloride ion concentration, decreased pH, or crack formation occur, the double-walled shell will accelerate the release of core components, achieving on-demand release, effectively improving the accuracy of protection, and avoiding the failure of conventional corrosion inhibitors due to early depletion; (3) The nano zinc and nano magnesium sacrificial anode particles of this invention preferentially consume themselves under corrosive conditions to protect the cathode area of ​​the steel reinforcement, while the generated corrosion products deposit to form a film and fill the pores, forming a secondary physical barrier; and capture Cl with layered bimetallic hydroxide LDH. - And releases passivating anions in synergy to form a continuous and stable passivation environment. This dual effect greatly improves the steel reinforcement’s resistance to chloride ion corrosion; (4) The rust inhibitor of the present invention can not only be used as a concrete admixture for long-term internal addition, but can also be made into a coating slurry to form a temporary protective film during the construction stage, preventing the steel reinforcement from early corrosion caused by marine atmospheric salt spray before pouring. In the early stage of service, the outer shell degradation and the release of corrosion inhibitor continue to provide protection, realizing a seamless connection between the construction period and the service period protection, and avoiding the protection gap period; (5) The rust inhibitor of the present invention does not use toxic solvents in the preparation process, and all materials are environmentally friendly; the particle size of the double-walled shell nano-microcapsules is comparable to that of cement particles, and its addition to concrete does not affect workability and mechanical properties. The nanostructure coating can prevent excessive reaction with pore liquid in the early stage, avoid the failure of traditional nano-magnesium materials in the early stage of mixing, and take into account both environmental safety and long-term effectiveness. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating the preparation process of the rust inhibitor of the present invention. Detailed Implementation

[0013] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0014] This invention provides a rust inhibitor for marine reinforced concrete. The rust inhibitor is a double-walled shell nanocapsule powder, comprising a core phase and an outer shell phase, the outer shell phase comprising an inner shell and an outer shell. The core phase, by weight, comprises at least one of inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjusting and mineralizing components, and / or sacrificial anode particles. The outer shell phase, by weight, comprises an inner shell, an outer shell, and nano-additives. The average particle size of the double-walled shell nanocapsules is 50–100 μm. The rust inhibitor provides triple protection in marine reinforced concrete, including physical barrier, electrochemical stabilization, and nanostructure self-adaptation.

[0015] The inner shell is selected from one of modified epoxy resin, polylactic acid (PLA), and polymethyl methacrylate (PMMA); the outer shell is selected from one of alginate / calcium, polyvinyl alcohol (PVA), and chitosan; the nano-additive is selected from one or more of nano-SiO2, layered bimetallic hydroxide (LDH), and graphene oxide (GO).

[0016] The inorganic corrosion inhibitor is selected from one or more of nitrite, phosphate, and molybdate; the organic corrosion inhibitor and film-forming component is selected from one or more of tannic acid, phytic acid, sebacic acid, and palmitamine; the pH adjusting and mineralizing component is selected from one or more of calcium hydroxide microcrystals, magnesia, and calcium phosphate precursors; the sacrificial anode particles are selected from one or more of nano-zinc and nano-magnesium. Sacrificial anode particles refer to nanoscale metal particles encapsulated in the core phase, used to act as micro-sacrificial anodes around the reinforcing steel, preferentially corroded to protect the steel; morphology and location: the particles are tens to hundreds of nanometers in size, initially encapsulated in the core phase by double-walled nanocapsules; when triggering conditions occur (pH decrease, Cl...),... - When the temperature rises (or cracks are under stress), the microcapsules release the material as needed to the vicinity of the steel-concrete interface. The particles and steel reinforcement form a microcouple in the concrete pore fluid; the sacrificial anode particles corrode first, pushing the steel reinforcement to the cathode side, thus protecting it; their corrosion products (such as Zn(OH)₂, ZnO, Mg(OH)₂) deposit at the interface to form a film / fill the pores, acting as a secondary physical barrier, increasing local alkalinity, and inhibiting corrosion propagation; synergistically with nano-additives such as layered bimetallic hydroxide (LDH): LDH captures Cl₂... - It also releases passivating anions to stabilize the passivation environment of the steel reinforcement. In this way, nano-sizing results in a milder reaction, more uniform dispersion, and a larger effective area; microcapsules avoid excessively rapid reactions in the early stages of mixing (especially since nano-magnesium is prone to over-reaction in strong alkaline aqueous solutions), and postpone the release until it is truly needed, thus balancing safety and long-term effectiveness.

[0017] The core phase formulation range (based on core phase mass) is: 10–60 wt% inorganic corrosion inhibitor, 2–20 wt% organic corrosion inhibitor and film-forming component, 10–50 wt% pH adjustment and mineralization component, and 1–10 wt% sacrificial anode particles; the shell phase formulation range (based on shell phase mass) is: 5–25 wt% inner shell, 5–15 wt% outer shell, and 0.1–5 wt% nano-additives.

[0018] The outer shell swells or partially dissolves in high-alkali / high-salt / high-humidity environments to achieve early release, while the inner shell provides slow release and long-lasting protection. When localized pH decreases, chloride ion concentration increases, or cracks are stressed in the concrete, the double-walled nanocapsules accelerate the release of the core phase as needed, thereby forming a biomimetic pore sealing and repassivation at the steel-concrete interface.

[0019] The nano-additive contains layered bimetallic hydroxide (LDH), which can capture Cl. - And release passivating anions (NO2) - or CO3 2- Electrochemical stabilization is achieved in synergy with the inorganic corrosion inhibitors of the core phase.

[0020] The rust inhibitor can be mixed with water to form a coating slurry, which is then applied to the surface of steel bars or concrete to form an early temporary protective film. This early temporary protective film is formed by the outer shell and organic corrosion inhibitors and film-forming components. It self-dissolves in the later stages of service and does not affect the concrete matrix.

[0021] The triple-layer synergistic protection principle: This rust inhibitor integrates three protective mechanisms: physical barrier, electrochemical passivation stabilization, and nanostructure self-adaptation. First, through the physical barrier effect, a temporary protective film is formed on the concrete pores and the surface of the reinforcing steel, preventing the penetration of moisture and chloride salts (equivalent to putting a protective coat on the reinforcing steel). Second, the rust inhibitor gradually releases electrochemical stabilizers (corrosion inhibitors), increasing the alkalinity of the solution around the reinforcing steel or providing passivating ions, maintaining the stability of the passivation film on the reinforcing steel, thereby increasing the chloride ion corrosion threshold. Third, with the help of nanostructures (such as nanocapsules), it achieves sensitive response and functional self-adaptation to environmental stimuli: when an increase in chloride ion concentration, pH change, or corrosion signal from cracks is detected, the nanocapsules undergo structural changes or rupture, releasing the corresponding anti-corrosion substances. For example, when the local pH value inside the concrete decreases (a precursor to reinforcing steel passivation failure), the microcapsules automatically decompose under acid and alkali stimulation, releasing alkaline corrosion inhibitors to neutralize the acidity, restore alkalinity, and repassivate the surface of the reinforcing steel.

[0022] Biomimetic Sealing and Self-Healing Mechanisms: Certain active ingredients in corrosion inhibitors can induce the formation of biomimetic sealing layers on the surface of reinforcing steel or in the pores of concrete. For example, the corrosion inhibitor contained in the microcapsules reacts with surrounding ions to generate insoluble products (similar to the mineral deposits or calcareous skeletons of shells), which automatically deposit on the steel-concrete interface and the inner walls of cracks, blocking pores and microcracks, thereby physically sealing the channels of corrosive media. This biomimetic sealing structure can gradually form over time, somewhat similar to the process by which corals and shellfish deposit mineral layers on their surfaces to resist seawater erosion. Simultaneously, the corrosion inhibitor also possesses a self-healing function: when microcracks appear in concrete due to impact loads or fatigue, the microcapsules dispersed in the matrix rupture under mechanical force, releasing the corrosion inhibitor, which fills and seals the cracks and forms a protective layer on the newly exposed steel surface.

[0023] Coupling of Electrochemical Stabilization and Cathodic Protection: The electrochemical mechanism of rust inhibitors also includes providing the dual functions of cathodic protection and anodic passivation. This involves the introduction of trace amounts of controllably released cationic corrosion inhibitors (such as calcium and magnesium ions) and nanoscale sacrificial anode particles. For example, nano-zinc or magnesium particles are encapsulated in microcapsules, which, upon early exposure, act as miniature sacrificial anodes for the reinforcing steel, preferentially consuming themselves to protect the cathodic region. Subsequently, their corrosion products (oxides, hydroxides) further act as a barrier covering the steel surface. Simultaneously, core corrosion inhibitors such as rust-inhibiting ions (e.g., low-toxicity molybdate and phosphate ions) are slowly released and adsorbed onto the steel surface to form a molecular passivation film, reducing anodic dissolution and cathodic oxygen depolarization reactions. Through this synergistic electrochemical mechanism, the environment surrounding the reinforcing steel... / It maintains a safe range and increases the threshold for resistance to chloride ion corrosion. These effects occur under the intelligent control of the micro-nano structure, and only take effect when corrosive conditions are triggered, thus ensuring long-term effectiveness while avoiding excessive application and environmental burden.

[0024] A method for preparing a rust inhibitor for marine reinforced concrete includes: a double emulsification step: a core aqueous phase containing inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjustment and mineralization components, and / or sacrificial anode particles is subjected to W / O primary emulsification with an inner shell organic phase, followed by W / O / W secondary emulsification with an outer shell aqueous phase; W / O: an oil-in-water emulsion, in which the aqueous phase (the core aqueous phase, containing corrosion inhibitors / mineralization solutes, etc.) is dispersed into many small water droplets, suspended in the oil phase (the inner shell organic phase), which is a continuous phase. W / O / W: a water / oil / water dual emulsion (secondary emulsification), first obtaining the above W / O droplets, and then using these water droplets in the oil as dispersion units to further disperse them into the outer shell aqueous phase, thus forming a double-layer structure of water droplets → oil layer → outer aqueous phase. First, W / O: The functional components (inorganic corrosion inhibitors, organic corrosion inhibitors and film-forming components, pH adjusters and mineralizers, sacrificial anode particles) from the core aqueous phase are encapsulated in the organic phase of the inner shell, laying the foundation for inner shell formation. Then, W / O / W: These W / O droplets are dispersed into the aqueous phase of the outer shell, thus simultaneously forming a double-layered shell structure: inner shell (oil phase solidification) + outer shell (aqueous phase cross-linking). Shell formation steps: The organic phase solvent of the inner shell is volatilized to solidify the inner shell, and then... (The sentence is incomplete and requires further context to translate accurately.) 2+ Cross-linking and curing of the outer shell; spray drying step: The stable bilayer emulsion is spray-dried to obtain bilayer shell nanocapsule powder with an average particle size of 50–100 μm. A rust inhibitor is added to marine reinforced concrete mixtures at 1.0–3.0 wt% of the cementitious material mass, providing triple protection of physical barrier, electrochemical stability, and nanostructure self-adaptation throughout the service life of the concrete. The shell thickness, porosity, and trigger sensitivity of the microcapsules can be controlled by adjusting the formulation and process parameters. For example, increasing the proportion of polyvinyl alcohol (PVA) or alginate in the outer layer accelerates its dissolution in water, allowing for earlier release of the corrosion inhibitor for surface film formation; increasing the thickness of the inner hydrophobic polymer layer delays the long-term release of the core corrosion inhibitor. No toxic solvents are used throughout the preparation process, and all materials are environmentally friendly. The resulting rust inhibitor powder can be directly added to the concrete mixture or formulated into a coating slurry.

[0025] Long-lasting rust inhibitors in concrete: Haiji rust inhibitor is mainly used as a concrete admixture. During the mixing stage, microcapsule powder is directly added to the mixture at 1%–3% of the cementitious material mass, ensuring uniform distribution within the concrete matrix. Because the microcapsule surface is a hydrophilic polymer, it disperses well without affecting the workability of the fresh concrete; its particle size is equivalent to that of cement mortar components, so it does not significantly weaken mechanical properties. After incorporating microcapsules, the concrete possesses inherent anti-corrosion properties throughout its hardening and service life: in highly alkaline environments, the microcapsules slowly release small amounts of corrosion-inhibiting substances, increasing the alkalinity of the pore fluid; when external chloride salts gradually penetrate, the microcapsule shell undergoes gradual degradation due to ion penetration and high salt induction, accelerating the release of corrosion inhibitors to combat chloride ion erosion. Once cracks or signs of localized corrosion appear, the microcapsules respond more rapidly in the corresponding areas (mechanical rupture or pH-stimulated decomposition), directionally releasing effective corrosion-inhibiting components to promptly passivate exposed steel reinforcement and seal cracks. It can automatically function when the passivation of steel bars is damaged, maintaining a high alkalinity by continuously supplying Ca(OH)2, thereby repassivating the steel bars and significantly slowing down the corrosion process. Therefore, adding this rust inhibitor to marine concrete can provide active protection throughout the entire structural lifespan, eliminating the need for frequent maintenance and reinforcement in the future.

[0026] Temporary Surface Protection: In addition to internal application, this corrosion inhibitor can also be used as a temporary coating for the protection of reinforcing steel or concrete surfaces during the construction phase. On-site, the microcapsule powder can be mixed with water to form an emulsion and brushed onto the reinforcing steel surface, or sprayed onto the exposed surface of concrete components to form a thin film. Because the microcapsule shell contains film-forming polymers and rapidly released organic corrosion inhibitors, a continuous and dense protective film forms on the substrate surface within hours of application, blocking marine salt spray and moisture intrusion. This coating maintains its corrosion protection throughout the construction period and the early service life of the structure. For example, in the construction of harbor piers, the reinforcing steel is often exposed to the marine atmosphere after binding and before pouring; brushing on this corrosion inhibitor emulsion can prevent premature corrosion of the steel. After pouring, the microcapsules solidify on the surface along with the hardened concrete, continuing to provide a barrier and corrosion-inhibiting ions initially. Once the structure has stabilized in service, this film and shell polymer will automatically degrade or fuse with the substrate under the influence of the high alkalinity of the concrete and natural biological action. For example, polyvinyl alcohol (PVA) / alginate can be hydrolyzed by alkali or slowly degraded by marine bacteria, eventually disappearing without affecting the appearance and durability of concrete. The combination of early temporary coating and later self-degradation solves the problem of the protective gap in the early stages of construction, achieving a continuous functional transition of the rust inhibitor from construction to long-term service.

Claims

1. A corrosion inhibitor for marine reinforced concrete, characterized by: The rust inhibitor is a double-layer wall shell nanocapsule powder, the double-layer wall shell nanocapsule comprises a core phase and a shell phase, the shell phase comprises an inner shell and an outer shell; wherein: The core phase comprises at least one of inorganic corrosion inhibitor component, organic corrosion inhibitor and film forming component, pH adjusting and mineralizing component and / or sacrificial anode particles by mass of the core phase; The shell phase comprises an inner shell, an outer shell and a nano additive by mass of the shell phase; The average particle size of the double-layer wall shell nanocapsule is 50-100 μm; The rust inhibitor is used to provide physical barrier, electrochemical stability and nano-structure self-adaptive triple protection in marine reinforced concrete.

2. A corrosion inhibitor for marine reinforced concrete according to claim 1, characterized in that: The inner shell is selected from one of modified epoxy resin, polylactic acid, polymethyl methacrylate; The outer shell is selected from one of alginate / calcium, polyvinyl alcohol, chitosan; The nano additive is selected from one or more of nano-SiO2, layered double hydroxide, graphene oxide.

3. A corrosion inhibitor for marine reinforced concrete according to claim 2, wherein: The inorganic corrosion inhibitor component is selected from one or more of nitrite, phosphate, molybdate; The organic corrosion inhibitor and film forming component is selected from one or more of tannic acid, phytic acid, decamethonium, palm amine; The pH adjusting and mineralizing component is selected from one or more of calcium hydroxide microcrystal, magnesia, calcium phosphate precursor; The sacrificial anode particles are selected from one or more of nano-zinc, nano-magnesium.

4. A corrosion inhibitor for marine reinforced concrete according to claim 3, wherein: The core phase formula range is: inorganic corrosion inhibitor component 10-60 wt%, organic corrosion inhibitor and film forming component 2-20 wt%, pH adjusting and mineralizing component 10-50 wt%, sacrificial anode particles 1-10 wt%; The shell phase formula range is: inner shell 5-25 wt%, outer shell 5-15 wt%, nano additive 0.1-5 wt%.

5. A corrosion inhibitor for marine reinforced concrete according to claim 4, wherein: The outer shell swells or partially dissolves in high-alkali / high-salt / high-humidity environment to achieve early release, and the inner shell provides slow release and persistent protection; when the pH of the concrete locally decreases, the concentration of chloride ions increases or the stress of the crack, the double-layer wall shell nanocapsule releases the core phase as needed to form a biomimetic sealing and repassivation at the steel-concrete interface.

6. A corrosion inhibitor for marine reinforced concrete according to claim 5, wherein: The nano-additive comprises a layered double metal hydroxide capable of capturing Cl - and releasing passivating anions, synergizing with the inorganic corrosion-inhibiting components of the core phase to achieve electrochemical stability.

7. A corrosion inhibitor for marine reinforced concrete according to claim 6, wherein: The rust inhibitor can be made into a coating slurry with water, coated on the surface of the steel bar or concrete to form an early temporary protective film, which is formed by the outer shell and the organic corrosion inhibitor and film forming component, and self-dissolves in the later service period without affecting the concrete matrix.

8. The method of claim 7, wherein the corrosion inhibitor for marine reinforced concrete is prepared by adding 0.1 to 0.3 parts by weight of the corrosion inhibitor to 100 parts by weight of the cement. It comprises: Double emulsification step: W / O primary emulsification of the core phase aqueous phase comprising inorganic corrosion inhibitor component, organic corrosion inhibitor and film forming component, pH adjusting and mineralizing component and / or sacrificial anode particles, and W / O / W secondary emulsification with the outer shell aqueous phase; Shell forming step: volatilizing the inner shell organic phase solvent to solidify the inner shell and by Ca 2+ crosslinking and solidifying the outer shell; Spray drying step: spray drying of the stable double emulsion to obtain double-layer wall shell nanocapsule powder with an average particle size of 50-100 μm.

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