CN110699691B - A metal-organic framework corrosion inhibitor hydrogel composite material and its preparation method and application - Google Patents

Abstract

The invention discloses a metal-organic framework corrosion inhibitor ^hydrogel composite material and its application. Corrosion inhibitor supported by @MIL‑124(Ga) and encapsulated by temperature-sensitive hydrogel to form a reusable corrosion inhibitor hydrogel composite. The corrosion inhibitor hydrogel composite of the present invention may release the corrosion inhibitor through the windowing effect to perform targeted repair of the corrosion site, and the temperature-sensitive hydrogel can be easily peeled off and recovered by phase separation after the corrosion inhibitor film-forming protection MOF and temperature-sensitive hydrogel play the role of "flaw detection band-aid" for corrosion of marine engineering steel structures. The use of the corrosion inhibitor hydrogel composite can realize the integration of quantitative detection, sensitive response and protection and repair functions of marine corrosion, which has significant application value and broad market prospects.

Description

A metal organic framework corrosion inhibitor hydrogel composite material and preparation method thereof application

technical field

The invention relates to the technical field of marine iron and steel anti-corrosion coating materials, and more particularly, to a metal-organic framework corrosion inhibitor hydrogel composite material and a preparation method and application thereof.

Background technique

At present, my country's ocean development has entered a golden age. However, ocean corrosion is a major problem in the process of ocean development, which seriously restricts the development of my country's ocean economy. The marine environment is the most corrosive natural environment. Seawater is a highly corrosive electrolyte solution containing a large amount of salts, including sodium chloride and salts containing potassium, bromine, iodine and other elements. Marine corrosion will cause damage to the steel structure of marine engineering, shorten the service life, and lead to serious economic losses and even safety accidents. The application of Migrating Corrosion Inhibitor (MCI) as a simple, economical and efficient anticorrosion material for marine steel is an important method to prevent marine corrosion.

Although the corrosion inhibitor has excellent anticorrosion performance, it is prone to occur in the marine environment and has a very limited service life. At present, the commonly used solution is to use nano-microcapsules to encapsulate the corrosion inhibitor, dope it into the coating and then coat it on the surface of the substrate to achieve the effect of slow release or even controllable release. However, the response of microcapsules to the primary site of corrosion is mainly based on the stress cracking of the coating under the condition of micro-cracks, which belongs to the response of physical action. Compared with the response of corrosion product ion chemical action, its sensitivity is relatively slow and it is difficult to identify corrosion In the induction stage, protection and repair can only be carried out in the stage of corrosion development. In addition, the barrier of the coating will also affect the flexibility of the microcapsules and the permeability of the corrosion inhibitor, reducing the corrosion inhibition effect.

Metal-Organic Frameworks (MOFs) have the advantages of tunable pore size, functional designability, excellent thermal and chemical stability, convenient and simple synthesis, etc., and are widely used in gas storage and separation, catalysis, chemical And physical sensing, drug delivery, proton conduction, optoelectronics, imaging and other fields have huge potential applications. Among them, luminescent MOFs materials are due to their abundant luminescent sites, metal ions, organic ligands and guest molecules in their composition can be used as luminescent centers, as well as the advantages of tunable framework structure and host-guest interaction. The fields of detection and temperature imaging are widely reported. In marine engineering, the corrosion product ion in the corrosion induction stage is Fe ³⁺ , and the corrosion product ion in the corrosion development stage is Fe ²⁺ . Xu et al. (2015) disclosed a fluorescent probe Eu ³⁺ @MIL-124 with high selectivity and sensitivity towards Fe ³⁺ and Fe ²⁺ ions, which is the first reported fluorescence probe with excellent performance in aqueous environment Europium ion functionalized doped metal-organic framework material (Xu XY, Yan ^B.Eu (III)-Functionalized MIL- ^124as Fluorescent Probe for Highly Selectively Sensing Ions and Organic Small Molecules Especially for Fe(III) and Fe(II) [J]. ACS Applied Materials & Interfaces, 2015, 7(1): 721-729.), which can be used in displays or lighting light-emitting devices; however, At present, there is no relevant report on its use in response to, identifying the ion chemical action of marine corrosion products and targeting the repair of corrosion sites; and the existing nano-microcapsule-encapsulated corrosion inhibitors for marine anti-corrosion are basically One-time use, cannot be recycled and reused.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned defects and deficiencies in the prior art, and to provide a metal organic framework corrosion inhibitor hydrogel composite material.

Another object of the present invention is to provide a preparation method of the metal organic framework corrosion inhibitor hydrogel composite material.

Another object of the present invention is to provide the application of the metal organic framework corrosion inhibitor hydrogel composite material.

The above-mentioned purpose of the present invention is achieved by the following technical solutions:

A metal-organic framework corrosion inhibitor hydrogel composite material is composed of a metal-organic framework material Eu ³⁺ @MIL-124(Ga) loaded with a corrosion inhibitor and a temperature-sensitive hydrogel encapsulated on its surface.

In the present invention, the europium ion-functionalized gallium-based metal-organic framework material Eu ³⁺ @MIL-124(Ga) is used as a fluorescent probe for detecting and identifying corrosion product ions and a carrier for corrosion inhibitor, a temperature-sensitive hydrogel Then it is used as the carrier of the metal-organic framework material Eu ³⁺ @MIL-124(Ga) loaded with corrosion inhibitor. The metal organic framework material Eu ³⁺ @MIL-124(Ga) is Eu ³⁺ @MIL-124, and the chemical formula of MIL-124 is Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ ), Eu ³⁺ The formula for @MIL-124 is [Eu ³⁺ ][Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )] ₃ . The fluorescence properties of the metal-organic framework material Eu ³⁺ @MIL-124(Ga) can realize specific responses to the corrosion product ^ions (Fe 3+ in the induced stage and Fe ²⁺ in the development stage) of steel in the marine environment, It has the characteristics of high sensitivity, high identification and high selectivity, and can realize specific response detection in all stages of corrosion. The corrosion inhibitor hydrogel composite is obtained by using the above-mentioned metal organic framework material with a high load of corrosion inhibitor and encapsulating it through a temperature-sensitive hydrogel. The obtained composite can further detect and repair the corrosion of marine steel structures. . It is based on the exchange behavior of corrosion product ions and MOF guest metal ions; at the same time, the windowing effect of the MOF framework structure caused by the ion exchange process can realize the sensitive response release of the corrosion inhibitor. Specifically, Eu ³⁺ ions in Eu ³⁺ @MIL-124(Ga) produce different fluorescence phenomena (quenching) through the exchange of corrosion product ions (Fe ³⁺ , Fe ²⁺ ) in different corrosion induction and development periods of steel. , discoloration) and its intensity, so as to accurately locate and quantitatively detect the corrosion site, and release the encapsulated corrosion inhibitor through the fenestration effect for targeted repair of the corrosion site. The use of temperature-sensitive hydrogel as the carrier makes the composite have the advantages of easy coating, peeling and recyclability, which facilitates the recycling of MOF and hydrogel, and acts as a "flaw detection band-aid" for marine steel structures as a whole. It does not need to be doped in the coating and then coated on the surface of the substrate like the traditional nano-microcapsule encapsulated corrosion inhibitor, because the effect of the corrosion inhibitor is fully exerted due to the less barrier of the coating.

Preferably, the Eu ³⁺ @MIL-124(Ga) is obtained by coordinating the carbonyl group in the layered MIL-124(Ga) channel with the Eu ³⁺ cation to obtain Eu ³⁺ @MIL-124(Ga) . Specifically, the MIL-124(Ga) prepared by the hydrothermal reaction undergoes a coordination reaction with Eu ³⁺ to obtain Eu ³⁺ @MIL-124(Ga), and the MIL-124(Ga) and Eu ³⁺ in the coordination reaction The dosage ratio is 2:1; more specifically, in order to take MIL-124(Ga) and EuCl ₃ ·6H ₂ O, soak in excess ethanol for 48-72 h, centrifuge, and repeatedly wash the precipitate with ethanol, and then vacuum dry is Eu ³⁺ @MIL-124(Ga).

Theoretically, the corrosion inhibitor is a chemical substance or compound that can prevent or slow down the corrosion of steel materials and can be supported in the metal-organic framework material Eu ³⁺ @MIL-124(Ga) without affecting their respective properties; preferably , the corrosion inhibitor is benzotriazole, also known as benzotriazole (BTA); the obtained metal-organic framework material supporting the corrosion inhibitor is BTA@Eu ³⁺ @MIL-124(Ga).

Preferably, the thermosensitive hydrogel is P(NIPAM-co-AAc). P(NIPAM-co-AAc) hydrogel is easy to be coated on the surface of the steel structure to be tested. P(NIPAM-co-AAc) is a solution when the temperature is below 46 °C, and cross-linking occurs when the temperature is above 46 °C. Phase separation realizes the stripping, separation and purification of the complex, recovers MOF and P(NIPAM-co-AAc) from it, and reduces the cost by reuse.

Preferably, the loading content of the corrosion inhibitor in the metal organic framework material is 7.62-10.6%, and the content is mass content; the loading efficiency is 63-68%.

Preferably, the content of the corrosion inhibitor-loaded metal-organic framework material Eu ³⁺ @MIL-124(Ga) in the temperature-sensitive hydrogel is 0.07-0.10%, and the content is mass content.

The present invention also provides the preparation method of any of the above-mentioned metal organic framework corrosion inhibitor ^hydrogel composite materials. , then the precipitate was collected by centrifugation and vacuum dried to obtain the inhibitor-loaded metal-organic framework material Eu ³⁺ @MIL-124(Ga); and then the dissolved temperature-sensitive hydrogel was fully mixed with the above-mentioned metal-organic framework material to obtain Metal-organic framework corrosion inhibitor hydrogel composites.

Preferably, the molar ratio of the corrosion inhibitor to Eu3+@MIL-124(Ga) is 5:6-8.

Preferably, the mass ratio of the corrosion inhibitor-loaded metal-organic framework material Eu ³⁺ @MIL-124(Ga) to the temperature-sensitive hydrogel is 0.7-1:1000.

The present invention also claims to protect the application of the metal-organic framework material Eu ³⁺ @MIL-124(Ga) in the preparation of marine anti-corrosion coating materials; specifically, in the preparation of ions (Fe ³⁺ and Fe ²⁺ ) and coating materials for targeted repair of corrosion sites.

The present invention also provides the application of any one of the above-mentioned metal-organic framework corrosion inhibitor hydrogel composite materials in marine anti-corrosion, which is to coat any of the above-mentioned metal-organic framework corrosion inhibitor hydrogel composite materials On the surface of the steel structure, after the repair is completed, the temperature of the hydrogel is changed to cause phase separation, peeled off from the surface of the steel structure, and MIL-124(Ga) and hydrogel are purified and recovered for reuse.

Specifically, the purification and recovery include dissolving the complex in ultrapure water at room temperature, filtering, recovering the filtrate to obtain a hydrogel, repeatedly washing the precipitate with nitric acid, and vacuum drying to obtain MIL-124(Ga). Using the recovered MIL-124(Ga) and temperature-sensitive hydrogel, the above-mentioned metal-organic framework corrosion inhibitor hydrogel composite material can be further prepared.

Preferably, the thickness of the composite material anchored on the surface of the steel structure to be repaired is 0.5-2 mm.

Compared with the prior art, the present invention has the following beneficial effects:

1. Recyclable. The metal-organic framework corrosion inhibitor hydrogel composite material of the invention can realize the integration of quantitative detection, sensitive response and protection and repair functions of marine corrosion, and takes the hydrogel as a carrier to coat the marine steel structure for detection and repair. , using its temperature-sensitive phase separation feature, it can be easily peeled off and separated from MOF, and MIL-124(Ga) and hydrogel can be recovered after washing, which greatly saves the application cost. It does not need to be doped in the coating and then coated on the surface of the substrate like the traditional nano-microcapsule encapsulated corrosion inhibitor, because the effect of the corrosion inhibitor is fully exerted due to the less barrier of the coating.

2. Strong applicability. The metal-organic framework corrosion inhibitor hydrogel composite material of the invention has a wide range of applications, and has excellent corrosion detection, repair and protection performance in both the corrosion induction period and the corrosion development period of the marine steel structure.

3. Efficiency. The metal-organic framework corrosion inhibitor hydrogel composite material of the invention has a small amount of material, can be coated on the surface of marine steel structure in a large area, can detect the corrosion of the steel structure, and at the same time effectively suppress the damage of the steel structure in the corrosive medium.

4. Fluorescence detection. The metal-organic framework corrosion inhibitor hydrogel composite material of the invention can realize high-sensitivity, high-discrimination and high-selective fluorescence detection of ions of corrosion products in marine engineering, so as to locate the sites in the corrosion induction period and the development period.

5. Targeted release and self-healing. The metal-organic framework corrosion inhibitor hydrogel composite material of the present invention acts on the corrosive medium, can target identification and release of aggressive ion chloride ions, and at the same time perform corrosion repair on corroded steel bars to prevent further corrosion of steel bars.

6. Good durability. The metal-organic framework corrosion inhibitor hydrogel composite material of the present invention has the ability to respond to the release of corrosion product ions (Fe ²⁺ and Fe ³⁺ ions) in the environment, and can detect corrosion through fluorescence while releasing the rust inhibitor. Product ions can be used to locate corrosion sites and maintain high corrosion inhibition efficiency in an acidic environment for a long time.

Description of drawings

Fig. 1 is the synthetic route and application principle of the corrosion inhibitor hydrogel composite provided in the embodiment of the present invention.

Detailed ways

The present invention is further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

The invention realizes high sensitivity, high identification and high selectivity fluorescence based on the exchange behavior of Eu ³⁺ ions between BTA@Eu ³⁺ @MIL-124(Ga) layers and product ions in different corrosion stages of steel structures in marine environment Detection, specifically, the fluorescence quenching after the exchange of Eu ³⁺ ions with Fe ³⁺ ions in the corrosion-inducing period, and the fluorescence from red to blue after the exchange with Fe ²⁺ ions in the corrosion development period, and the intensity is weakened. The effect of releasing the sequestered BTA repairs and protects the corrosion site, and using the P(NIPAM-co-AAc) hydrogel as the carrier makes the corrosion inhibitor hydrogel composite of the present invention easy to coat on the surface of the marine steel structure, After ion-exchange fluorescence detection and corrosion inhibitor repair and film-forming protection, changing the temperature makes the hydrogel carrier phase-separate, which is easy to peel off, and facilitates the recycling of MOF and P(NIPAM-co-AAc), which plays a role in marine steel as a whole. The role of structural "flaw detection Band-Aid".

In marine engineering, the fluorescent probe of the complex has different characteristics of fluorescence response to corrosion product ions in different stages (Fe ^{3+ in the induced stage and Fe 2+ in} the development stage), and has high sensitivity, high identification and high Selectivity is characterized, and its detection principle is based on the exchange behavior of corrosion product ions with guest metal ions in MOF. At the same time, the windowing effect of the MOF framework caused by the ion exchange process can realize the sensitive response release of the corrosion inhibitor. As a carrier for encapsulating BTA@Eu ³⁺ @MIL-124(Ga), P(NIPAM-co-AAc) is easy to coat on the surface of steel structures, and can accurately locate and detect corrosion-induced and developmental sites while also enabling The corrosion inhibitor is released through the fenestration effect for targeted repair of the corrosion site. After the corrosion inhibitor film-forming protection, the temperature-sensitive hydrogel can be easily peeled off through phase separation and the MOF and P(NIPAM-co-AAc) can be recovered easily. Play the role of "flaw detection Band-Aid" for corrosion of marine engineering steel structures. The use of the corrosion inhibitor hydrogel composite can realize the integration of quantitative detection, sensitive response and protection and repair functions of marine corrosion, which has significant application value and broad market prospects.

Example 1 Preparation of europium ion-functionalized gallium-based metal-organic framework material Eu ³⁺ @MIL-124(Ga)

Synthesis of Eu ³⁺ @MIL-124(Ga), the chemical reaction equation is as follows:

2Ga(NO ₃ ) ₃ +4H ₂ O+C ₉ H ₆ O ₆ =Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )+6HNO ₃ (1)

Eu ³⁺ +3Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )=[Eu ³⁺ ][Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )] ₃ (2)

1. First, 1.2g Ga(NO ₃ ) ₃ ·xH ₂ O, 0.74g trimellitic acid (molar ratio of 4:3) and 10mL ultrapure water were mixed at room temperature and stirred for 30min to obtain mixture A. The mixture A was transferred to a Teflon-lined hydrothermal synthesis reactor, and the mixture B was obtained after heating at 210 °C for 24 h. The initial pH values before and after heating were 0.4 and 0.6, respectively. The mixture B was centrifuged at 13,000 rpm for 5 min to obtain a white solid powder, which was washed three times with ultrapure water and dried at 100° C. for 24 h to obtain MIL-124(Ga). Take 0.2 g of prepared MIL-124(Ga) and 0.4 mol EuCl ₃ ·6H ₂ O, soak in 15 mL of ethanol for 48 h, centrifuge, wash with ethanol, and vacuum dry at 80 °C for 6 h to obtain europium ion-functionalized gallium-based Metal organic framework material [Eu ³⁺ ][Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )] ₃ , denoted as Eu ³⁺ @MIL-124(Ga).

2. Measure the Eu ³⁺ @MIL-124(Ga) obtained above to verify the successful encapsulation of Eu ³⁺ , specifically:

Test method: Take 2mg of the above Eu ³⁺ @MIL-124(Ga) and 2mL of MCl _x (Mn ⁺ =K ⁺ , Na ⁺ , Hg ²⁺ , Cd ²⁺ , 1×10 ^-2 mol/L) respectively. Ca ²⁺ , Ni ²⁺ , Co ²⁺ , Mn ²⁺ , Cu ²⁺ , Fe ²⁺ , Fe ³⁺ , Al ³⁺ ) solutions were mixed at room temperature, and another 2 mg of the above Eu ³⁺ @MIL-124 ( Ga) was mixed with 2 mL of ultrapure water at room temperature, and the fluorescence spectra of each group of mixtures were measured respectively, and then the mixtures containing Fe ³⁺ and Fe ²⁺ were irradiated with 254 nm ultraviolet light, respectively.

According to the measurement method given above, it is experimentally measured that the mixture containing Fe ³⁺ has no emission peak, while the mixture containing Fe ²⁺ has a weak emission peak at 615nm, and the other mixtures have strong emission peaks at 615nm; UV at 254nm Under the irradiation of light, the mixture containing Fe ³⁺ has no fluorescence, while the mixture containing Fe ²⁺ has weak blue light, and the other mixtures have strong red fluorescence. This indicates that Eu ³⁺ has been successfully encapsulated into MIL-124(Ga), and the fluorescence properties of Eu ³⁺ @MIL-124(Ga) can specifically detect the presence of Fe ³⁺ emission and Fe ²⁺ .

Example 2

1. Preparation of Corrosion Inhibitor Hydrogel Composites Based on Eu ³⁺ Functionalized Ga-MOF Encapsulated BTA

Step 1: Preparation of BTA@Eu ³⁺ @MIL-124(Ga)

Take 0.12g of Eu ³⁺ @MIL-124(Ga) and 0.013g of benzotriazole (BTA) prepared in the above example, stir in 15mL methanol solution for 12h, then centrifuge at 5500rpm for 20min, at 100 After drying at ℃ for 6 h, the metal-organic framework material BTA@Eu ³⁺ @MIL-124(Ga) supported by BTA was obtained.

Step 2: Preparation of BTA@Eu ³⁺ @MIL-124(Ga) corrosion inhibitor hydrogel composites.

2.26 g of isopropylacrylamide, 0.154 g of N,N'-methylenebisacrylamide and 0.289 g of acrylic acid were added to 100 mL of ultrapure water, heated to 70 °C under nitrogen protection, and stirred at a speed of 600 rpm. After 1 h, dissolve 1.5 mg of potassium persulfate in 1 mL of ultrapure water, and add it dropwise to the mixture, resulting in turbidity. After 4 h, the heating was stopped. After the mixture was cooled to room temperature, it was stirred under nitrogen protection for 24 h, and then dialyzed with ultrapure water for 7 days. P(NIPAM-co-AAc) hydrogel was obtained after lyophilization. Take 100 g of the hydrogel solution and 0.1 g of the prepared BTA@Eu ³⁺ @MIL-124(Ga), and after thorough mixing, the BTA@Eu ³⁺ @MIL-124(Ga) corrosion inhibitor hydrogel composite was obtained.

2. Measure the relative fluorescence intensity of the above-mentioned corrosion inhibitor hydrogel complex

Condition: The experimental material is carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), and the corrosion inhibitor is selected from the above examples 3-12 to prepare the corrosion inhibitor hydrogel composite; medium It is 3.5% sodium chloride solution, the dosage is 300mL, and the temperature is 35 °C; carbon steel is pre-treated with 8 times of alternating dry and wet environment before coating the corrosion inhibitor hydrogel composite; when the coating is completed and after 48 hours of coating respectively Measure its fluorescence spectrum, then heat the hydrogel to 50 °C to make it phase-separate and peel off from the carbon steel surface. After peeling, the complex is placed in 100 mL of ultrapure water to dissolve at room temperature, filtered, and the filtrate is recovered to obtain P(NIPAM -co-AAc), the precipitate was repeatedly washed with nitric acid, and MIL-124(Ga) was obtained after vacuum drying. Using the recovered MIL-124(Ga) and P(NIPAM-co-AAc), the corrosion inhibitor hydrogel complex was re-prepared as described in Examples 1 and 2, and the experiment was re-experimented according to the above test method, and its fluorescence spectrum was measured. Repeat the operation 8 times.

The above-mentioned corrosion inhibitor hydrogel composite obtained the relative fluorescence intensity of 8 repeated operations through the experimental test according to the above-mentioned determination method, respectively: 2.46%, 2.44%, 2.45%, 2.42%, 2.38%, 2.39%, 2.36%, 2.34%, indicating that the complex is a recyclable and stable fluorescent probe for corrosion product ions.

Examples 3 to 12

According to the preparation process of the corrosion inhibitor hydrogel composite described in Example 2, according to the recorded use range of the raw materials, adjusting the dosage of the raw materials can obtain the corrosion inhibitor supported by different amounts of BTA@Eu ³⁺ @MIL-124(Ga). Corrosion inhibitor hydrogel composite, changing the number of alternating dry and wet treatments of carbon steel (that is, before coating the corrosion inhibitor hydrogel composite, the carbon steel was first immersed in 3.5% sodium chloride solution for 8h, and then taken out in the Humidity 50% and temperature 25°C drying for 16h, one treatment cycle is 24h), and the temperature of sodium chloride solution soaked in carbon steel to carry out the design of the examples (see Table 1).

Table 1 Condition Design of Examples 3 to 12

Performance Testing

The corrosion inhibitor hydrogel composites described in Examples 3 to 12 were tested for their corrosion product ion detection performance and corrosion inhibition efficiency.

1. Conditions: The experimental material is carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), and the corrosion inhibitor is selected from the above examples 3-12 to prepare the corrosion inhibitor hydrogel composite ; The medium is 3.5% sodium chloride solution, the dosage is 300 mL, and the temperature is set according to the solution temperature described in Table 1; the carbon steel is set in advance according to the setting described in Table 1 before coating the corrosion inhibitor hydrogel composite. Alternate treatment, and then coating the above example to obtain the corrosion inhibitor hydrogel composite, the temperature is 35 ° C, after 48 hours, the composite is peeled off by physical cross-linking, and the fluorescence spectrum is measured before the coating is completed and before peeling off.

According to GB10124-88 "Metal Materials Laboratory Uniform Corrosion Full Immersion Test Method", the weight loss test was carried out, and the corrosion inhibition performance was characterized by electrochemical AC impedance spectroscopy and potentiodynamic polarization. The experimental test methods used are from the literature: [1] W.Li, L.Hu, S. Zhang, B. Hou, Effects of two fungicides on the corrosion resistance of copper in 3.5%NaCl solution under various conditions [J], Corros .Sci.2011,53:735-745 (Determination of rust inhibition efficiency by weight loss experiment and electrochemical impedance spectroscopy experiment)【2】H.Tian,W.Li,B.Hou.Novel application of a hormone biosynthetic inhibitor for the corrosion resistance enhancement of copper in synthetic seawater[J].Corros.Sci.2011,53:3435–3445.(The rust inhibition efficiency was measured by potentiodynamic polarization curve experiment).

2. Results

The corrosion inhibitor hydrogel composites obtained in Examples 3 to 12 are obtained by experimental tests according to the above-mentioned determination methods, and the corrosion inhibition efficiency and relative fluorescence intensity are shown in Table 2:

Table 2 Corrosion inhibition efficiency and relative fluorescence intensity of the corrosion inhibitor hydrogel composites described in Examples 3 to 12

weightlessness Electrochemical Impedance Spectroscopy Potentiodynamic polarization curve Relative fluorescence intensity Example 3 93.4% 93.7% 94.6% 2.44% Example 4 94.3% 94.5% 94.8% 2.38% Example 5 95.3% 96.1% 96.6% 2.53% Example 6 96.3% 96.6% 96.8% 2.47% Example 7 98.3% 97.7% 98.5% 48.2% Example 8 96.5% 97.1% 97.6% 0.23% Example 9 95.4% 95.3% 96.1% 1.77% Example 10 96.5% 96.7% 96.9% 2.32% Example 11 96.1% 96.3% 95.9% 2.47% Example 12 95.6% 95.8% 96.2% 2.45%

The above test results show that the metal organic framework corrosion inhibitor hydrogel composite material of the present invention has recyclable, low dosage, high sensitivity, high identification and high selectivity fluorescence detection to locate the corrosion induction period and development period. The characteristics of the site can act on the corrosive medium, identify and release the aggressive ion chloride ions, and at the same time repair the corroded steel bar, prevent further corrosion of the steel bar, and maintain a high level in an acidic environment for a long time. Corrosion Inhibition Efficiency. The metal-organic framework corrosion inhibitor hydrogel composite material of the invention can realize the integration of quantitative detection, sensitive response and protection and repair functions of marine corrosion, and has significant application value and broad market prospect.

Claims (10)

1. a metal-organic framework corrosion inhibitor hydrogel composite material is characterized in that, by the metal-organic framework material Eu ³⁺ @MIL-124 (Ga) of load corrosion inhibitor and the temperature-sensitive type encapsulated on its surface Hydrogel composition; the Eu ³⁺ @MIL-124(Ga) is obtained by the coordination reaction between the carbonyl group in the layered MIL-124(Ga) channel and the Eu ³⁺ cation, and the MIL-124(Ga) ) has the formula Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ ), and Eu ³⁺ @MIL-124 has the formula [Eu ³⁺ ][Ga ₂ (OH) ₄ (C ₉ O ₆ H ₄ )] ₃ . 2 . The metal organic framework corrosion inhibitor hydrogel composite material according to claim 1 , wherein the corrosion inhibitor is benzotriazole. 3 . 3 . The metal-organic framework corrosion inhibitor hydrogel composite material according to claim 1 , wherein the temperature-sensitive hydrogel is P(NIPAM-co-AAc). 4 . 4 . The metal organic framework corrosion inhibitor hydrogel composite material according to claim 1 or 2 , wherein the loading content of the corrosion inhibitor in the metal organic framework material is 7.62-10.6%. 5 . 5. The metal-organic framework corrosion inhibitor hydrogel composite material according to claim 1 or 3, wherein the corrosion inhibitor-loaded metal-organic framework material Eu ³⁺ @MIL-124(Ga) is in The content in the thermosensitive hydrogel is 0.07-0.10%. 6. The preparation method of metal-organic framework corrosion inhibitor hydrogel composite material according to any one of claims 1 to 5, wherein the Eu ³⁺ @MIL-124(Ga) and the corrosion inhibitor are soaked in excess alcohol The solution was stirred for 12-24 h, then the precipitate was collected by centrifugation and dried in vacuum to obtain the metal-organic framework material Eu ³⁺ @MIL-124(Ga) loaded with corrosion inhibitor; The metal-organic framework material of the etchant is fully mixed to obtain a metal-organic framework corrosion inhibitor hydrogel composite. 7 . The preparation method according to claim 6 , wherein the molar ratio of the corrosion inhibitor to Eu3+@MIL-124(Ga) is 5:6～8. 8 . 8 . The preparation method according to claim 6 , wherein the mass ratio of the corrosion inhibitor-loaded metal-organic framework material Eu ³⁺ @MIL-124(Ga) to the temperature-sensitive hydrogel is 0.7～8 . 1:1000. 9. Application of the metal-organic framework corrosion inhibitor hydrogel composite material according to any one of claims 1 to 5 in the preparation of marine anti-corrosion coating materials. 10 . The application of the metal organic framework corrosion inhibitor hydrogel composite material according to any one of claims 1 to 5 in marine anticorrosion, characterized in that the metal organic framework corrosion inhibitor according to any one of claims 1 to 5 is used The etchant hydrogel composite material is coated on the surface of the steel structure. After the repair is completed, the temperature of the hydrogel is changed to make it phase-separate, peeled off from the surface of the steel structure, and MIL-124(Ga) and hydrogel are purified and recovered. , reused.

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