Anti-corrosion method for realizing precise release of corrosion inhibitor by intelligent self-sensing

Abstract

The application discloses a kind of corrosion protection method for realizing precision release of corrosion inhibitor by intelligent self-sensing, the method comprises the following steps: one, styrene and NaOH are reacted under the action of initiator, and Ps microsphere dispersion is obtained;Two, CTAB is dissolved into alcohol aqueous solution, Ps microsphere dispersion, saturated ammonia, tetraethyl silicate are added, centrifugal washing is carried out, and porous hollow SiO2 microsphere powder is obtained after drying and calcining;Three, hollow SiO2 and 3-aminopropyl triethoxysilane are added in anhydrous ethanol, and SiO2-NH2 is obtained;Four, SiO2-NH2 particles and toluene are added with diselenium compound, centrifugal, washing, vacuum drying, and SiO2-NH-DSe is obtained;Five, benzotriazole is immersed into SiO2-NH-DSe, and functionalized hollow SiO2 microsphere loaded with BTA is obtained after drying. 3+ Stimulus response, precision release and effective corrosion passivation are combined, so that steel plate has excellent corrosion resistance.

Description

Technical Field

[0001] This invention relates to a Fe 3+ The method for irritant response and precise release of corrosion inhibitors specifically involves a method for corrosion prevention by utilizing diselenium bond (-Se-Se-) modification to achieve intelligent self-sensing and precise release of corrosion inhibitors. Background Technology

[0002] Corrosion is a major threat faced by countries worldwide, causing severe economic losses to human society. Research on corrosion protection is of significant scientific and practical importance. Coating technology is a commonly used corrosion protection method. However, coating technology faces a common problem: once the coating is damaged, corrosive media can directly penetrate to the metal substrate, rendering it ineffective in preventing corrosion.

[0003] Loading corrosion inhibitors into nanocontainers and then introducing them into coatings can effectively extend the service life of steel. However, because the surface of the nanocontainers is not functionalized, the release of corrosion inhibitors can easily become uncontrolled, leading to reduced barrier properties, adhesion, and corrosion resistance of the coating, premature failure of the corrosion inhibitors, and thus accelerating the corrosion rate of the metal. This necessitates surface modification of the nanocontainers to achieve precise release of corrosion inhibitors and passivation in the corrosive zone. Summary of the Invention

[0004] To address the technical challenge of controllable release of corrosion inhibitors in existing anti-corrosion coatings, this invention provides an intelligent, self-sensing method for precise release of corrosion inhibitors. This method utilizes the double selenium bond to Fe... 3+ Stimulus responsiveness effectively combines precise release and corrosion passivation, giving the steel plate excellent corrosion resistance.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A corrosion prevention method that enables precise release of corrosion inhibitors through intelligent self-sensing includes the following steps:

[0007] Step 1: Mix 10g of styrene with 10-50g of 10-20wt% NaOH solution, stir, let stand, separate the liquids, and then react the purified styrene in a water bath at 60-80℃ for 8-24h. Under the action of 0.1-0.5g of initiator (azobisisobutyronitrile (AIBN) or ammonium persulfate), styrene polymerizes to obtain Ps microsphere dispersion.

[0008] Step 2: Dissolve 0.5–2 g of hexadecyltrimethylammonium bromide (CTAB) in an alcohol-water solution (alcohol-water ratio of 1:3 / 1–1:1 / 3, for example: 1:3 / 1, 1:2, 1:1 / 3), then pour in 50–100 g of Ps microsphere dispersion and mechanically stir for 10–60 min; add 5–12.5 ml of saturated ammonia water, and after 1–5 min, add 10–30 ml of tetraethyl silicate dropwise at a rate of 5–12 d / min into a beaker; keep stirring and react for 20–30 h, then centrifuge and wash the prepared silica-coated polystyrene microspheres, dry them in a drying oven for 10–15 h, and take out the white powder sample; put the white powder into a crucible, and calcine it in a muffle furnace at a rate of 1–5 °C / min from room temperature to 500–800 °C, hold for 1–3 h, and then slowly cool to room temperature to obtain porous hollow SiO2 microsphere powder;

[0009] Step 3: Add 30-80 ml of anhydrous ethanol to a 250 ml three-necked flask, then add 0.5-1.5 g of hollow SiO2 and 0.5-1 ml of 3-aminopropyltriethoxysilane; heat in an oil bath at 40-60 °C and react for 10-15 h; after the reaction is complete, wash the product with anhydrous ethanol and dry it in a vacuum oven at 30-50 °C for 10-15 h to obtain the product SiO2-NH2;

[0010] Step 4: Take 0.5-1.5g of SiO2-NH2 particles and 20-60ml of toluene and add them to a three-necked flask. Then add 0.25-1ml of diselenide compound, heat in an oil bath at 60-80℃, and react for 20-30h. After the reaction is complete, centrifuge, wash with anhydrous ethanol, and then vacuum dry for 20-30h to obtain the product SiO2-NH-DSe.

[0011] Step 5: Using the vacuum impregnation method, 0.5-2g of corrosion inhibitor (benzotriazole (BTA) or 8-hydroxyquinoline) is impregnated into 1-3g of SiO2-NH-DSe, and then placed in an oven at 40-80℃ for 10-15h to evaporate the solvent. After drying, functionalized hollow SiO2 microspheres loaded with BTA are obtained.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] In harsh environments, steel is easily corroded to form Fe. 3+ The diselenium bond (-Se-Se-) is associated with Fe 3+ It possesses strong stimulus response performance. Porous hollow SiO2 has a large cavity and specific surface area, is odorless and non-toxic, has stable performance, and its preparation process is mature. This invention combines double selenium bonds (-Se-Se-) with hollow SiO2 loaded with corrosion inhibitors, which can effectively protect the corroded area, save on the amount of inhibitor used, and greatly extend the service life of coatings and steel. Attached Figure Description

[0014] Figure 1 SEM images and particle size distribution of Ps microspheres (approximately 1 μm) were obtained when the alcohol-to-water ratio was 120 / 20.

[0015] Figure 2 SEM images of porous hollow SiO2 at different ammonia contents (5ml, 7.5ml, 10ml, 12.5ml);

[0016] Figure 3 Comparative analysis of BTA release curves between SiO2@BTA and unfunctionalized SiO2@BTA microspheres;

[0017] Figure 4 EIS-Nyquist plot changes of blank sample, unfunctionalized SiO2@BTA, and pure steel plate in 5wt.% NaCl solution. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0019] This invention provides a method for corrosion prevention that enables precise release of corrosion inhibitors through intelligent self-sensing, the method comprising the following steps:

[0020] Step 1: Using polystyrene (Ps) as a rigid film for preparing porous core-shell SiO2, 10g of styrene was mixed with 30g of NaOH (20wt%) solution, stirred, and allowed to stand for 10 minutes. The mixture was then filtered to remove a small amount of polymerization inhibitor for purification. The purified styrene was added to a mixed solution with an alcohol-to-water ratio of 1:3 to 1:1:3, and reacted in a 70°C water bath for 12 hours. Under the action of 0.3g of azobisisobutyronitrile (AIBN) initiator, styrene polymerized to obtain Ps microsphere dispersions of different particle sizes.

[0021] Step 2: Dissolve 1g of CTAB in an alcohol-water solution (120ml ethanol + 20ml water), then pour in 85g of Ps microsphere dispersion and mechanically stir for 30min. Add a certain amount of saturated ammonia water (5ml, 7.5ml, 10ml, 12.5ml), and after 1min, add 20ml of tetraethyl orthosilicate dropwise to the beaker at a rate of 5-12 drops / min. Keep stirring and react for 24h. After that, centrifuge and wash the prepared silica-coated polystyrene (SiO2@Ps) microspheres several times, dry them in a drying oven for 12h, and take out the white powder sample. Place the powder in a crucible and calcine it in a muffle furnace at a rate of 2℃ / min from room temperature to 600℃, hold it at that temperature for 2h, and then slowly cool it to room temperature to obtain porous hollow SiO2 microsphere powder.

[0022] Step 3: Amino-modification (SiO2-NH2) of porous hollow SiO2 microsphere powder was performed. 50 ml of anhydrous ethanol was added to a 250 ml three-necked flask, followed by 1 g of hollow SiO2 and 0.5 ml of 3-aminopropyltriethoxysilane. The mixture was heated in an oil bath at 50 °C for 12 h. After the reaction, the product was washed three times with anhydrous ethanol. The product was then vacuum-dried at 40 °C for 12 h to obtain the SiO2-NH2 product.

[0023] Step 4: Grafting SiO2-NH2 with diselenylene bonds (SiO2-NH-DSe). Add 1g of SiO2-NH2 particles and 40ml of toluene to a three-necked flask, then add 0.5ml of the diselenylene compound. Heat in an oil bath at 60℃ for 24h. After the reaction is complete, centrifuge, wash three times with anhydrous ethanol, and then vacuum dry for 24h to obtain the product SiO2-NH-DSe.

[0024] Step 5: Using the vacuum impregnation method, 1g of corrosion inhibitor benzotriazole (BTA) is impregnated into 2g of SiO2-NH-DSe, and then placed in a 60℃ oven for 12h to evaporate the solvent. After drying, functionalized hollow SiO2 microspheres loaded with BTA (SiO2@BTA) are obtained.

[0025] This invention utilizes the diselenium bond (-Se-Se-) to Fe 3+ The controlled release performance of the corrosion inhibitor is achieved through stimulus responsiveness and the storage and release properties of porous hollow SiO2: Functionalized hollow SiO2 microspheres loaded with BTA (SiO2@BTA) are initially in a closed state, and the release amount of BTA is significantly less than that of unfunctionalized SiO2@BTA microspheres. When Fe is present in the solution... 3+ In the presence of (Se-Se), the polymer chains are oxidized and broken, resulting in the breakage of the originally extended polymer chains and the creation of pores. Large pores appear on the surface of SiO2@BTA microspheres. At this time, the amount of BTA released is only slightly lower than that of unfunctionalized SiO2@BTA microspheres.

[0026] SiO2@BTA microspheres and control samples were immersed in 5 wt.% NaCl solution, and the EIS-Nyquist plots of the samples were measured to evaluate their corrosion resistance. A larger diameter corresponding to the semicircular arc indicates superior barrier and corrosion resistance of the coating, while a smaller diameter indicates poorer corrosion resistance. Compared to samples without added or unfunctionalized SiO2-BTA, SiO2-BTA showed the least change in shrinkage with increasing immersion time, indicating that this sample exhibited significantly better corrosion resistance than other samples.

[0027] Experimental results:

[0028] 1. SEM images and particle size distribution of Ps microspheres obtained when the alcohol-water ratio is 120 / 20 are shown below. Figure 1 As shown. From Figure 1 The scanning electron microscope (SEM) image of Ps shown shows that when the alcohol / water ratio is 120 / 20, the prepared Ps microspheres have a uniform particle size distribution, a smooth surface, and a size of 0.98 μm.

[0029] 2. Different amounts of ammonia water (5ml) Figure 2 a) 7.5ml Figure 2 b) 10ml Figure 2 c) 12.5ml Figure 2 d)) Influence on the morphology of hollow SiO2 Figure 2 As shown in the SEM image, it can be observed that with increasing ammonia content, the particle size of the silica spheres constituting the shell structure gradually increases, from 1.22 micrometers to 1.67 micrometers. At higher ammonia contents, in... Figure 2 In sample d, significant and severe damage is clearly visible, indicating incomplete shell structure and uneven encapsulation; when the ammonia content is 7.5 mL, the synthesized hollow silica spheres exhibit intact structure, good sphericity, and uniform particle dispersion. Figure 2 b); When the ammonia content is low ( Figure 2 a) This leads to a thicker shell layer in the hollow spheres, resulting in larger silica particle sizes and increased particle accumulation on the sphere surface. In summary, the optimal dosage of ammonia is 7.5 mL, at which point hollow silica materials with good monodispersity, uniform coating, and high sphericity can be prepared.

[0030] 3. The specific surface area, pore size, and pore volume of Ps@SiO2 and hollow SiO2 microspheres are analyzed as shown in Table 1.

[0031] Table 1

[0032]

[0033] 4. The BTA release curves of sample C-unfunctionalized SiO2@BTA microspheres (without double selenium bond modification) and sample B-SiO2@BTA microspheres were compared, and the results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the amount of BTA released by SiO2@BTA microspheres is significantly less than that of unfunctionalized SiO2@BTA microspheres, and the slow-release rate is about 5 times lower. This indicates that the double selenium bond unit can slow down the release of BTA corrosion inhibitor from hollow SiO2 microspheres in water, thus playing a role in slow release. However, when Fe... 3+ When present, the diselenium bond is broken by Fe. 3+ Upon opening, the release rate was only slightly lower than that of sample C. This indicates that in Fe... 3+ Under the presence of these conditions, large pores appeared on the surface of SiO2@BTA microspheres. This is due to the presence of diselenium bonds in Fe. 3+ When the (Se-Se) condition is oxidized and broken, the originally extended polymer chains break down, thus creating pores and allowing BTA molecules to escape.

[0034] 5. Analysis of EIS-Nyquist plot changes of blank samples, unfunctionalized SiO2@BTA, and SiO2@BTA in pure steel plates in 5wt.% NaCl solution. Figure 4 As shown. By Figure 4 It can be seen that the pure steel plate without sample addition (5 wt.% NaCl solution, blank group) was severely corroded at the bottom after immersion for 24 hours. The sample without sample addition (5 wt.% NaCl solution) showed a Nyquist plot radius of approximately 0.5 x 10⁻⁶ after 24 hours of corrosion resistance testing. 3 ohm / cm 2 The Nyquist map radius of SiO2-BTA after 24 hours of corrosion resistance testing is approximately 4 x 10⁻⁶. 3 ohm / cm 2 The corrosion resistance was 10 times that of the blank sample. Pure steel plates containing SiO2 (control group) and SiO2-BTA with added 5wt.% NaCl solution exhibited a certain degree of corrosion resistance, with the SiO2-BTA sample showing the best corrosion resistance according to the Nyquist plot. EIS test results suggest that during the corrosion process of SiO2-BTA, BTA is released, and benzotriazole adsorbs onto the iron surface via its three nitrogen atoms, forming a membrane that inhibits further corrosion to some extent.

Claims

1. A corrosion prevention method that enables precise release of corrosion inhibitors through intelligent self-sensing, characterized in that... The method includes the following steps: Step 1: Mix 10 g of styrene with 10-50 g of 10-20 wt% NaOH solution, stir, let stand, separate the liquids, and then react the styrene in a water bath at 60-80 ℃ for 8-24 h. Under the action of 0.1-0.5 g initiator, styrene polymerizes to obtain Ps microsphere dispersion. Step 2: Dissolve 0.5-2 g CTAB in an alcohol-water solution, then pour in 50-100 g Ps microsphere dispersion and stir mechanically; add 5-12.5 ml saturated ammonia water, and after 1-5 min, add 10-30 ml tetraethyl silicate dropwise; keep stirring and react for 20-30 h, then centrifuge and wash the prepared silica-coated polystyrene microspheres, dry them in a drying oven, and take out the white powder sample; put the white powder into a crucible, and heat it in a muffle furnace from room temperature to 500-800 ℃ at a rate of 1-5 ℃ / min, keep it at this temperature for 1-3 h, and then slowly cool it to room temperature to obtain porous hollow SiO2 microsphere powder; Step 3: Add 30-80 ml of anhydrous ethanol to a 250 ml three-necked flask, then add 0.5-1.5 g of hollow SiO2 and 0.5-1 ml of 3-aminopropyltriethoxysilane; heat in an oil bath at 40-60 °C and react for 10-15 h; after the reaction is complete, wash with anhydrous ethanol and dry the product under vacuum to obtain the product SiO2-NH2; Step 4: Take 0.5~1.5g of SiO2-NH2 particles and 20~60 ml of toluene and add them to a three-necked flask. Then add 0.25~1 ml of diselenium compound, heat in an oil bath at 60~80 ℃, and react for 20~30 h. After the reaction is completed, centrifuge, wash with anhydrous ethanol, and then vacuum dry to obtain the product SiO2-NH-DSe. Step 5: Using the vacuum impregnation method, 0.5~2 g of corrosion inhibitor benzotriazole is impregnated into 1~3 g of SiO2-NH-DSe, and then placed in an oven to dry and evaporate the solvent. After drying, functionalized hollow SiO2 microspheres loaded with BTA are obtained.

2. The corrosion prevention method for achieving precise release of corrosion inhibitors through intelligent self-sensing as described in claim 1, characterized in that... In step one, the initiator is azobisisobutyronitrile or ammonium persulfate.

3. The corrosion prevention method for achieving precise release of corrosion inhibitors through intelligent self-sensing as described in claim 1, characterized in that... In step two, the volume ratio of alcohol to water is 12 / 2.

4. The corrosion prevention method for achieving precise release of corrosion inhibitor through intelligent self-sensing as described in claim 1, characterized in that... In step two, the amount of ammonia water added is 7.5 mL.

5. The corrosion prevention method for achieving precise release of corrosion inhibitor through intelligent self-sensing according to claim 1, characterized in that... In step two, the mechanical stirring time is 10-60 min; the tetraethyl silicate dropping rate is 5-12 d / min; and the drying time is 10-15 h.

6. The corrosion prevention method for achieving precise release of corrosion inhibitor through intelligent self-sensing according to claim 1, characterized in that... In step three, the vacuum drying temperature is 30~50 ℃ and the time is 10~15 h.

7. The corrosion prevention method for achieving precise release of corrosion inhibitor through intelligent self-sensing according to claim 1, characterized in that... In step four, the vacuum drying time is 20-30 hours.

8. The corrosion prevention method for achieving precise release of corrosion inhibitors through intelligent self-sensing as described in claim 1, characterized in that... In step five, the drying temperature is 40~80 ℃ and the time is 10~15 h.

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