Polyurea-based super-infiltration anti-scaling coating and preparation method thereof

Abstract

The invention relates to the technical field of scale inhibition coating preparation, in particular to a polyurea-based super-infiltration scale inhibition coating and a preparation method thereof.The preparation method comprises the following steps that a hybrid resin solution is obtained through in-situ hybridization, a low-surface-energy modifier is added into the hybrid resin solution to obtain a hydrophobically-modified organic-inorganic hybrid resin solution, and the hydrophobically-modified organic-inorganic hybrid resin solution is subjected to surface modification to obtain the polyurea-based super-infiltration scale inhibition coating. The preparation method comprises the following steps: preparing a hydrophobic slow-release nano-filler through a hydrothermal reaction, preparing microcapsule powder through in-situ polymerization, dispersing the hydrophobic slow-release nano-filler and the hydrophobic microcapsule powder into organic-inorganic hybrid resin, carrying out uniform ultrasonic dispersion, spraying to the surface of a matrix by using a spray gun, and calcining to obtain the polyurea-based super-infiltration coating. According to the invention, elastomer polyurea resin is used as a base material, through in-situ hybridization, chemical modification and filler ratio regulation and control, the coating is endowed with elastic response, the mechanical property of the coating is enhanced, and through super-hydrophobic and super-oleophylic selective super-wettability, dynamic conversion from a gas film to an oil film in a composite environment is realized.

Description

Technical Field

[0001] The invention relates to the technical field of scale-inhibiting coating preparation, and in particular to a polyurea-based super-wetting scale-inhibiting coating and a preparation method thereof. Background Art

[0002] With the rapid development of modern industry, production equipment generally faces serious scaling problems. Industrial circulating water systems, heat exchange equipment, and the inner wall of transportation pipelines are prone to stubborn scale layers, which not only reduce the heat transfer efficiency of the equipment, but also increase its energy consumption. In the chemical, electric power, metallurgical and other industries, scaling will increase the resistance of equipment operation, and even cause equipment blockage in severe cases, resulting in unplanned downtime accidents and major economic losses. In addition, the presence of scale layers will accelerate the electrochemical corrosion process of equipment, shorten the service life of equipment, and increase maintenance costs. What is more serious is that in some industrial environments, the sudden shedding of scale layers may cause equipment failures or safety accidents, posing a huge threat to the life safety of operators. Therefore, the development of efficient anti-scaling materials is of great practical significance. Such materials show broad application prospects in industrial production and are of great value in improving equipment operation efficiency, reducing maintenance costs, and ensuring production safety.

[0003] In response to the widespread scaling problem in the industrial field, researchers have carried out a lot of innovative research on anti-scaling technology. Among them, chemical scale inhibitors have become a research hotspot because of their simple operation and significant effect. For example, Chen Wenting et al. disclosed a high-temperature resistant scale inhibitor for oil field industrial environment in the patent with publication number CN119371598A. Zhang Lei et al. disclosed a composite scale inhibitor with strong dispersibility, good anti-sedimentation effect and phosphorus-free and environmentally friendly in the patent with publication number CN119349780A. Cui Yanyan et al. disclosed a scale inhibitor for calcium carbonate scale in the patent with publication number CN119143928A, and its scale inhibition rate can be as high as more than 90%. However, in actual industrial applications, traditional scale inhibitors still have obvious limitations, such as short action time and frequent addition; limited range of action, difficult to cope with complex working conditions; wastewater treatment is required after large-scale use, increasing industrial costs. Therefore, the development of long-term, broad-spectrum, and low-consumption anti-scaling methods has become an important direction of current research. On this basis, anti-scaling coating technology has attracted wide attention due to its advantages such as durability, environmental protection and economy. Zhao Junjie et al. disclosed in the patent with publication number CN118909161A an anti-scaling coating that can effectively alleviate the scaling of the reactor during the emulsion polymerization reaction, and its anti-scaling effect can be maintained for more than 6 months. In summary, preparing anti-scaling coating on the surface of industrial equipment is currently an ideal and convenient anti-scaling method.

[0004] In recent years, super-hydrophobic coatings with contact angles greater than 150° and sliding angles less than 10° have become a research hotspot due to their excellent anti-adhesion properties and outstanding performance in self-cleaning, anti-fouling, anti-icing, and anti-corrosion. Theoretical analysis and experimental studies have shown that the unique micro-nano composite structure, air film isolation effect, and low surface energy of the super-hydrophobic coating surface can effectively inhibit the adhesion and growth of scale, providing a new research direction for anti-scaling coating technology. However, in practical applications, the fine microstructure of the surface of traditional super-hydrophobic coatings is easily damaged by external mechanical friction or erosion by highly corrosive liquids, resulting in the failure of the air film isolation layer, thereby seriously reducing the protective performance of the coating. In addition, complex oil-water mixed systems are common in actual industrial application environments, in which the oil phase substances will contaminate the coating surface, which will also cause the air film isolation layer on the surface of the super-hydrophobic coating to fail and lose the anti-scaling effect. The above limitations seriously restrict the large-scale application of super-hydrophobic coatings under complex working conditions. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a polyurea-based super-wetting anti-scaling coating and a preparation method thereof. The present invention uses an elastomeric polyurea resin as a substrate, and through in-situ hybridization, chemical modification and filler ratio regulation, the coating is given an elastic response to enhance its mechanical properties, and through the selective super-wetting of super-hydrophobic and super-oleophilic, the dynamic conversion from air film to oil film in a composite environment is realized. Through hydrothermal synthesis, in-situ polymerization, organic-inorganic hybridization and chemical modification processes, a variety of hydrophobic fillers with sustained release functions are prepared, which solves the problems of large dosage, short action time and easy leakage of hydrophilic scale inhibitors and achieves long-term sustained release under simulated working conditions.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for preparing a polyurea-based super-wettable anti-fouling coating comprises the following steps: The inorganic titanium source is hydrolyzed to obtain titanium dioxide gel, the titanium dioxide gel is added to a polyurea resin solution, a hybrid resin solution is obtained through in-situ hybridization, a low surface energy modifier is added to the hybrid resin solution for hydrophobic modification, and a hydrophobically modified organic-inorganic hybrid resin solution is obtained.

[0007] The nanoparticles and the scale inhibitor are dispersed in water, and a hydrothermal reaction is performed to graft the scale inhibitor onto the nanoparticles. A low surface energy modifier is then added to perform hydrophobic modification, and the mixture is dried to obtain a hydrophobic slow-release nanofiller.

[0008] After adding prepolymer monomers to water, the pH is adjusted to 7-9, and after stirring, a wall material prepolymer is obtained. Then, a scale inhibitor, an emulsifier and a wall material prepolymer are added to an organic solvent and the pH is adjusted to 2-5, in-situ polymerization is performed, and drying is performed to obtain microcapsule powder. The microcapsule powder is dispersed in anhydrous ethanol, a low surface energy modifier is added for hydrophobic modification, and drying is performed to obtain a hydrophobic microcapsule powder.

[0009] The hydrophobic sustained-release nanofiller and hydrophobic microcapsule powder are dispersed in an organic-inorganic hybrid resin, uniformly dispersed by ultrasonication, sprayed onto the surface of a substrate using a spray gun, and calcined to obtain a polyurea-based super-wetting coating.

[0010] In terms of resin selection, the present invention uses an elastomeric polyurea resin as a base resin to give the coating excellent elastic response characteristics, thereby significantly improving its mechanical properties. The base polyurea resin is modified by in-situ hybridization and chemical modification technology, so that the coating has a special surface morphology while showing super-hydrophobic (water contact angle can reach more than 160°) and super-oleophilic (the contact angle of various oils is 0°) selective super-wetting properties. This characteristic enables the coating to efficiently capture oil droplets and complete interface replacement in an oil-water composite environment, converting the fragile air film into a durable, stable and more anti-adhesive oil film, thereby significantly improving the stability and service life of the coating. The hydrophobic microcapsule powder and hydrophobic sustained-release nanofiller prepared by the present invention through hydrothermal synthesis, in-situ polymerization and chemical modification technology, the hydrophobic long chain grafted on the outer layer can effectively solve the problems of large dosage, short residence time and insufficient effect of traditional scale inhibitors. At the same time, the coating forms a highly shielding oil film isolation layer in an oil-water composite environment through its super oleophilic property. The synergistic effect of the highly shielding oil film isolation layer and the slow-release filler realizes the combination of static / dynamic scale inhibition performance, giving the product excellent and lasting anti-scaling performance.

[0011] In a preferred embodiment of the present invention, the mass percentage of the sustained-release nanofiller in the hydrophobically modified organic-inorganic hybrid resin solution is 1% to 10%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 10% to 30%.

[0012] In a preferred embodiment of the present invention, the mass ratio of the inorganic titanium source to the polyurea resin solution is 0.1-1:1-10, and the mass ratio of the low surface energy modifier to the polyurea resin solution is 0.01-0.1:1-10.

[0013] In a preferred embodiment of the present invention, the mass ratio of nanoparticles to scale inhibitor is 0.01~0.1:1~10, the mass ratio of nanoparticles to low surface energy modifier is 0.01~0.1:0.01~0.1, the hydrothermal reaction temperature is 150℃~200℃, and the hydrothermal reaction time is 3h~6h.

[0014] In a preferred embodiment of the present invention, the mass ratio of the prepolymer monomer to the scale inhibitor and the emulsifier is 1-10:1-10:1-10, and the mass ratio of the prepolymer monomer to the low surface energy modifier is 1-10:0.01-0.1.

[0015] In a preferred embodiment of the present invention, the nanoparticles are one or more of nano-silicon dioxide, nano-bentonite, nano-titanium dioxide, and nano-graphite, and the scale inhibitor is one or more of ethylenediaminetetraacetic acid, polyepoxysuccinic acid, aminotrimethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, and hydroxyethylenediphosphonic acid.

[0016] In a preferred embodiment of the present invention, the prepolymer monomer is one or more of melamine, formaldehyde solution, triethanolamine, isocyanate, and polyether polyol.

[0017] In a preferred embodiment of the present invention, the emulsifier is one or more of polyethylene glycol (30), sorbitan fatty acid ester, polyoxyethylene castor oil, polyoxyethylene beeswax, and sodium dodecylbenzene sulfonate.

[0018] In a preferred embodiment of the present invention, the low surface energy modifier is one or more of perfluorooctyl triethoxysilane, dimethyl silicone oil, stearic acid, alkylphenol polyoxyethylene ether, and polyether-modified siloxane.

[0019] In a preferred embodiment of the present invention, the air pressure of the spray gun is 4 bar to 6 bar, the calcination temperature is 150° C. to 200° C., and the calcination time is 10 min to 30 min.

[0020] Another object of the present invention is to provide a polyurea-based super-wettable anti-fouling coating prepared by any of the preparation methods described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. In terms of resin selection, the present invention uses elastomeric polyurea resin as the base resin, giving the coating excellent elastic response characteristics, thereby significantly improving its mechanical properties. The base polyurea resin is modified by in-situ hybridization and chemical modification technology, so that the coating has a special surface morphology while showing super-hydrophobic (water contact angle can reach more than 160°) and super-oleophilic (the contact angle of various oils is 0°) selective super-wetting properties. This characteristic enables the coating to efficiently capture oil droplets and complete interface replacement in an oil-water composite environment, converting the fragile air film into a durable, stable and more anti-adhesive oil film, thereby significantly improving the stability and service life of the coating. The hydrophobic microcapsule powder and hydrophobic sustained-release nanofiller prepared by the present invention through hydrothermal synthesis, in-situ polymerization and chemical modification technology, the hydrophobic long chain grafted on the outer layer can effectively solve the problems of large dosage, short residence time and insufficient effect of traditional scale inhibitors. At the same time, the coating forms a highly shielding oil film isolation layer in an oil-water composite environment through its super oleophilic property. The synergistic effect of the highly shielding oil film isolation layer and the slow-release filler realizes the combination of static / dynamic scale inhibition performance, giving the product excellent and lasting anti-scaling performance.

[0022] 2. Compared with the solution of enhancing rigidity to resist external mechanical damage, the polyurea-based super-wetting coating prepared by the present invention effectively neutralizes the external mechanical stress applied to the coating surface through a flexible unloading mechanism, thereby avoiding the destruction of the microstructure and greatly extending the service life of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an electron microscope image of the surface of the polyurea-based super-wettable anti-fouling coating prepared in Example 1 of the present invention.

[0024] Figure 2 This is a test diagram of the contact angle of the polyurea-based super-wettable anti-fouling coating with water prepared in Example 1 of the present invention.

[0025] Figure 3 In the figure, (a) is the surface of the ordinary coating after the scaling test in Example 1, (b) is the electron microscope image of the coating surface of the polyurea-based super-wetting anti-scaling coating in the homemade simulated scaling liquid, and (c) is the electron microscope image of the coating surface in the oil-water composite scaling liquid.

[0026] Figure 4 It is the XRD spectrum of scale on the surface of different samples after the scaling test in Example 1 of the present invention, wherein Sample 1 is a common coating in a homemade simulated scaling liquid, Sample 2 is a polyurea-based super-wetting anti-scaling coating in a homemade simulated scaling liquid, and Sample 3 is a polyurea-based super-wetting anti-scaling coating in an oil-water composite scaling liquid.

[0027] Figure 5 These are the low-frequency impedance data of the polyurea-based super-wettable anti-scaling coating in Example 1 of the present invention after being immersed in an oil-water composite corrosive medium for 1, 3, 5, 7, and 15 days.

[0028] Figure 6 The figure shows an electron microscope image of the surface of the polyurea-based super-wettable anti-fouling coating prepared in Example 2 of the present invention.

[0029] Figure 7 The figure in the figure is a test diagram of the contact angle of the polyurea-based super-wettable anti-fouling coating with water prepared in Example 2 of the present invention.

[0030] Figure 8 In the figure, (a) is the surface of the ordinary coating after the scaling test in Example 2, (b) is the electron microscope image of the coating surface of the polyurea-based super-wetting anti-scaling coating in the homemade simulated scaling liquid, and (c) is the electron microscope image of the coating surface in the oil-water composite scaling liquid.

[0031] Fig. 9 It is the XRD spectrum of scale on the surface of different samples after the scaling test in Example 2 of the present invention, wherein Sample 1 is a common coating in a homemade simulated scaling liquid, Sample 2 is a polyurea-based super-wetting anti-scaling coating in a homemade simulated scaling liquid, and Sample 3 is a polyurea-based super-wetting anti-scaling coating in an oil-water composite scaling liquid.

[0032] Fig.10 These are the low-frequency impedance data of the polyurea-based super-wettable anti-scaling coating in Example 2 of the present invention after being immersed in an oil-water composite corrosive medium for 1, 3, 5, 7, and 15 days. DETAILED DESCRIPTION

[0033] The following is a detailed description of the technical solutions in the embodiments of the present invention in combination with the preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods.

[0035] Example 1 A method for preparing a polyurea-based super-wettable anti-fouling coating comprises the following steps: (1) Surface pretreatment of metal substrate First, the surface of the aluminum substrate was polished with 400-mesh sandpaper to remove the surface oxide film, and the polishing waste was washed with deionized water. Then, 600-mesh and 800-mesh sandpaper were used to perform multiple deep polishing. The polished aluminum plate was then placed in a mixed solution of ethanol and water for ultrasonic cleaning (V ethanol: V water = 1:1) to remove grease, dust and other impurities on the surface. After cleaning, the aluminum plate was placed in a constant temperature oven at 80°C for drying.

[0036] (2) Preparation of coating solution In a 50°C water bath environment, a mixed solution of 0.6 parts of deionized water and 2 parts of anhydrous ethanol was added dropwise to a mixed solution of 0.6 parts of tetrabutyl titanate and 3 parts of anhydrous ethanol, and magnetically stirred until completely hydrolyzed to obtain a mixed solution. The above mixed solution was added dropwise to 10 parts of J-6736 aqueous polyurea resin solution, and magnetically stirred to obtain a hybrid resin solution. After adding 0.05 parts of perfluorooctyl triethoxysilane to the above hybrid resin solution, magnetic stirring was continued for 2 hours to obtain a hydrophobically modified organic-inorganic hybrid resin solution.

[0037] 0.05 parts of nano-silica and 0.5 parts of antiscalant ethylenediaminetetraacetic acid were dispersed in 100 parts of deionized water, and hydrothermally reacted at 180°C for 4 hours. The hydrothermal reaction product was then dried and dispersed in 100 parts of anhydrous ethanol. 0.05 parts of low surface energy modifier perfluorooctyltriethoxysilane were added, stirred, and dried to obtain a hydrophobic sustained-release nano-silica filler.

[0038] After adding 2 parts of melamine and 4 parts of formaldehyde solution to 5 parts of deionized water, the pH is adjusted to 8, and the wall material prepolymer is obtained after stirring. Then, 0.5 parts of antiscalant polyepoxysuccinic acid, 3 parts of emulsifier polyethylene glycol (30) and the wall material prepolymer are added to 150 parts of xylene and the pH is adjusted to 4. After stirring, a uniform emulsion is obtained. The emulsion is further stirred to obtain a dispersion, and the dispersion is post-treated to obtain microcapsule powder. The microcapsule powder is dispersed in 100 parts of anhydrous ethanol, and 0.1 parts of a low surface energy modifier perfluorooctyl triethoxysilane is added, stirred, and dried to obtain a hydrophobic microcapsule powder.

[0039] The microcapsule powder and the sustained-release nano-silica filler are uniformly dispersed in the hydrophobically modified organic-inorganic hybrid resin solution by using an ultrasonic cleaning machine to form a uniform resin solution for standby use, wherein the mass percentage of the sustained-release nano-filler in the hydrophobically modified organic-inorganic hybrid resin solution is 5%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 25%.

[0040] (3) The treated aluminum plate is sprayed at a constant temperature of 60°C, and the resin solution is sprayed onto the surface of the treated aluminum plate using a spray gun at an air pressure of 5 bar. The coating is then placed in a programmable temperature-controlled box and calcined at 180°C for 20 min. After being taken out, the coating is naturally cooled to room temperature to obtain a polyurea-based super-wetting anti-fouling coating.

[0041] Example 2 A method for preparing a polyurea-based super-wettable anti-fouling coating comprises the following steps: (1) Surface pretreatment of metal substrate First, the surface of the aluminum substrate was polished with 400-mesh sandpaper to remove the surface oxide film, and the polishing waste was washed with deionized water. Then, 600-mesh and 800-mesh sandpaper were used to perform multiple deep polishing. The polished aluminum plate was then placed in a mixed solution of ethanol and water for ultrasonic cleaning (V ethanol: V water = 1:1) to remove grease, dust and other impurities on the surface. After cleaning, the aluminum plate was placed in a constant temperature oven at 80°C for drying.

[0042] (2) Preparation of coating solution In a 50°C water bath environment, a mixed solution of 0.4 parts of deionized water and 8 parts of anhydrous ethanol was added dropwise to a mixed solution of 0.4 parts of ethyl titanate and 12 parts of anhydrous ethanol, and magnetically stirred until completely hydrolyzed to obtain a mixed solution. The above mixed solution was added dropwise to 7 parts of J-999 aqueous polyurea resin solution, and magnetically stirred to obtain a hybrid resin solution. After adding 0.07 parts of alkylphenol polyoxyethylene ether to the above hybrid resin solution, magnetic stirring was continued for 2 hours to obtain a hydrophobically modified organic-inorganic hybrid resin solution.

[0043] 0.01 parts of nano-bentonite and 1.0 parts of scale inhibitor aminotrimethylenephosphonic acid were dispersed in 100 parts of deionized water, and hydrothermally reacted at 180°C for 4 hours. The hydrothermal reaction product was then dried and dispersed in 150 parts of anhydrous ethanol. 0.04 parts of low surface energy modifier alkylphenol polyoxyethylene ether were added, stirred, and dried to obtain a hydrophobic sustained-release nano-bentonite filler.

[0044] After adding 4 parts of melamine and 6 parts of formaldehyde solution to 10 parts of deionized water, the pH is adjusted to 8, and the wall material prepolymer is obtained after stirring. Then, 1.0 parts of scale inhibitor polyepoxysuccinic acid, 5 parts of emulsifier polyoxyethylene castor oil and the wall material prepolymer are added to 110 parts of ethyl acetate and the pH is adjusted to 4. After stirring, a uniform emulsion is obtained, and the emulsion is further stirred to obtain a dispersion, and the dispersion is post-treated to obtain microcapsule powder. The microcapsule powder is dispersed in 100 parts of anhydrous ethanol, and 0.15 parts of low surface energy modifier alkylphenol polyoxyethylene ether are added, stirred, and dried to obtain hydrophobic microcapsule powder.

[0045] The microcapsule powder and the sustained-release nano-bentonite filler are uniformly dispersed in the hydrophobically modified organic-inorganic hybrid resin solution by using an ultrasonic cleaning machine to form a uniform resin solution for standby use, wherein the mass percentage of the sustained-release nano-filler in the hydrophobically modified organic-inorganic hybrid resin solution is 5%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 25%.

[0046] (3) The treated aluminum plate was sprayed at a constant temperature of 75°C, and then the coating was placed in a programmable temperature-controlled box and calcined at 200°C for 10 min. After being taken out, the coating was naturally cooled to room temperature to obtain a polyurea-based super-wetting anti-fouling coating.

[0047] Example 3 A method for preparing a polyurea-based super-wettable anti-fouling coating comprises the following steps: (1) Surface pretreatment of metal substrate First, the surface of the aluminum substrate was polished with 400-mesh sandpaper to remove the surface oxide film, and the polishing waste was washed with deionized water. Then, 600-mesh and 800-mesh sandpaper were used to perform multiple deep polishing. The polished aluminum plate was then placed in a mixed solution of ethanol and water for ultrasonic cleaning (V ethanol: V water = 1:1) to remove grease, dust and other impurities on the surface. After cleaning, the aluminum plate was placed in a constant temperature oven at 80°C for drying.

[0048] (2) Preparation of coating solution In a 50°C water bath environment, a mixed solution of 0.6 parts of deionized water and 2 parts of anhydrous ethanol was added dropwise to a mixed solution of 1 part of tetrabutyl titanate and 3 parts of anhydrous ethanol, and magnetically stirred until completely hydrolyzed to obtain a mixed solution. The above mixed solution was added dropwise to 8 parts of J-6736 aqueous polyurea resin solution, and magnetically stirred to obtain a hybrid resin solution. After adding 0.01 parts of perfluorooctyl triethoxysilane to the above hybrid resin solution, magnetic stirring was continued for 2 hours to obtain a hydrophobically modified organic-inorganic hybrid resin solution.

[0049] 0.01 parts of nano-silica and 5 parts of antiscalant ethylenediaminetetraacetic acid were dispersed in 100 parts of deionized water, and hydrothermally reacted at 180°C for 4 hours. The hydrothermal reaction product was then dried and dispersed in 100 parts of anhydrous ethanol. 0.05 parts of low surface energy modifier perfluorooctyltriethoxysilane were added, stirred, and dried to obtain a hydrophobic sustained-release nano-silica filler.

[0050] After adding 1 part of melamine and 9 parts of formaldehyde solution to 5 parts of deionized water, the pH is adjusted to 7, and the wall material prepolymer is obtained after stirring. Then, 1 part of scale inhibitor polyepoxysuccinic acid, 3 parts of emulsifier polyethylene glycol (30) and the wall material prepolymer are added to 150 parts of xylene and the pH is adjusted to 2. After stirring, a uniform emulsion is obtained. The emulsion is further stirred to obtain a dispersion, and the dispersion is post-treated to obtain microcapsule powder. The microcapsule powder is dispersed in 100 parts of anhydrous ethanol, and 0.1 parts of a low surface energy modifier perfluorooctyl triethoxysilane is added, stirred, and dried to obtain a hydrophobic microcapsule powder.

[0051] The microcapsule powder and the sustained-release nano-silica filler are uniformly dispersed in the hydrophobically modified organic-inorganic hybrid resin solution by using an ultrasonic cleaning machine to form a uniform resin solution for standby use, wherein the mass percentage of the sustained-release nano-filler in the hydrophobically modified organic-inorganic hybrid resin solution is 1%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 10%.

[0052] (3) The treated aluminum plate is sprayed at a constant temperature of 60° C., and the resin solution is sprayed onto the surface of the treated aluminum plate using a spray gun at an air pressure of 4 bar. The coating is then placed in a programmable temperature-controlled box and calcined at 150° C. for 10 min. After being taken out, the coating is naturally cooled to room temperature to obtain a polyurea-based super-wetting anti-fouling coating.

[0053] Example 4 A method for preparing a polyurea-based super-wettable anti-fouling coating comprises the following steps: (1) Surface pretreatment of metal substrate First, the surface of the aluminum substrate was polished with 400-mesh sandpaper to remove the surface oxide film, and the polishing waste was washed with deionized water. Then, 600-mesh and 800-mesh sandpaper were used to perform multiple deep polishing. The polished aluminum plate was then placed in a mixed solution of ethanol and water for ultrasonic cleaning (V ethanol: V water = 1:1) to remove grease, dust and other impurities on the surface. After cleaning, the aluminum plate was placed in a constant temperature oven at 80°C for drying.

[0054] (2) Preparation of coating solution In a 50°C water bath environment, a mixed solution of 0.6 parts of deionized water and 2 parts of anhydrous ethanol was added dropwise to a mixed solution of 1 part of tetrabutyl titanate and 3 parts of anhydrous ethanol, and magnetically stirred until completely hydrolyzed to obtain a mixed solution. The above mixed solution was added dropwise to 1 part of J-6736 aqueous polyurea resin solution, and magnetically stirred to obtain a hybrid resin solution. After adding 0.05 parts of perfluorooctyl triethoxysilane to the above hybrid resin solution, magnetic stirring was continued for 2 hours to obtain a hydrophobically modified organic-inorganic hybrid resin solution.

[0055] 0.01 parts of nano-silica and 0.5 parts of antiscalant ethylenediaminetetraacetic acid were dispersed in 100 parts of deionized water, and hydrothermally reacted at 180°C for 4 hours. The hydrothermal reaction product was then dried and dispersed in 100 parts of anhydrous ethanol. 0.05 parts of low surface energy modifier perfluorooctyltriethoxysilane were added, stirred, and dried to obtain a hydrophobic sustained-release nano-silica filler.

[0056] After adding 2 parts of melamine and 4 parts of formaldehyde solution to 5 parts of deionized water, the pH is adjusted to 9, and the wall material prepolymer is obtained after stirring. Then, 0.5 parts of antiscalant polyepoxysuccinic acid, 3 parts of emulsifier polyethylene glycol (30) and the wall material prepolymer are added to 150 parts of xylene and the pH is adjusted to 5. After stirring, a uniform emulsion is obtained. The emulsion is further stirred to obtain a dispersion, and the dispersion is post-treated to obtain microcapsule powder. The microcapsule powder is dispersed in 100 parts of anhydrous ethanol, and 0.1 parts of a low surface energy modifier perfluorooctyl triethoxysilane is added, stirred, and dried to obtain a hydrophobic microcapsule powder.

[0057] The microcapsule powder and the sustained-release nano-silica filler are uniformly dispersed in the hydrophobically modified organic-inorganic hybrid resin solution by using an ultrasonic cleaning machine to form a uniform resin solution for standby use, wherein the mass percentage of the sustained-release nano-filler in the hydrophobically modified organic-inorganic hybrid resin solution is 10%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 30%.

[0058] (3) The treated aluminum plate is sprayed at a constant temperature of 60°C, and the resin solution is sprayed onto the surface of the treated aluminum plate using a spray gun at an air pressure of 6 bar. The coating is then placed in a programmable temperature-controlled box and calcined at 200°C for 30 min. After being taken out, the coating is naturally cooled to room temperature to obtain a polyurea-based super-wetting anti-fouling coating.

[0059] Performance test of coating prepared in Example 1 Wettability: The wettability of the coating surface in Example 1 was measured using a static contact angle meter (JGW-360A). Figure 1 and Figure 2 The following are the surface morphology and contact angle test images of the coating. A drop of deionized water / kerosene was dropped on the coating surface using a 10 μL syringe. The water contact angle was measured to be 166°, while the kerosene was completely spread on the coating surface with a contact angle of 0°. In addition, the coating was tested with a simulated high-mineralization aqueous solution (CaCl 2 / NaHCO 3 ) can also reach a contact angle of more than 160°.

[0060] Scale inhibition performance: The polyurea-based super-wettable anti-scaling coating prepared in Example 1 was immersed in 500 mL of a homemade simulated scaling solution (containing 0.01 mol / L CaCl2 , 0.01 mol / L NaHCO 3 ) and 500 mL of oil-water composite scaling solution (containing 0.01 mol / L CaCl 2 , 0.01 mol / L NaHCO 3 , 5 wt% kerosene), and the scale inhibition performance test was carried out under simulated working conditions of 60℃ water bath and 125 rpm magnetic stirring. After 24 hours of continuous testing, the scale amount reached 0.23 mg / cm 2 Compared with the pure coating sample, the prepared polyurea-based super-wetting anti-scaling coating showed a negative mass growth phenomenon in both test environments, which was attributed to the mass loss caused by the continuous release of antiscalant by the slow-release filler in the coating. The crystal structure of scale on the coating surface was further characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results are as follows Figure 3 and Figure 4 As shown in the figure, the results show that in the homemade simulated scaling liquid, the calcium carbonate scale on the surface of the polyurea-based super-wetting anti-scaling coating presents a peculiar flower-like chelate state, which is the result of the slow-release scale inhibitor. In the oil-water composite environment, almost no calcium carbonate crystals are formed on the coating surface, and the surface calcium content is only 4.27 wt%, indicating that the super-wetting coating has excellent scale inhibition performance in the oil-water mixed environment.

[0061] Mechanical durability test: The wear resistance of the coating samples was evaluated using a TABER wear tester (JST-3393). During the experiment, 1000-grit sandpaper was used as an abrasive and the test was performed under a constant load of 250 g. After 700 wear cycles, the water contact angle of the prepared polyurea-based super-wetting anti-fouling coating remained at 151°, while the oil contact angle remained stable at 0°. When the wear cycle increased to 1000 times, macroscopic observation revealed that there was no obvious damage to the coating surface, while still maintaining high hydrophobicity (>140°) and super-oleophilic properties (oil contact angle = 0°), indicating that the coating has excellent mechanical stability.

[0062] Corrosion resistance: The prepared coating was titrated using an acid-base solution with a pH of 1 to 14. The results showed that its water contact angle was stably maintained at about 166°. To further evaluate the corrosion resistance of the coating, the samples were immersed in a strong acid solution with a pH of 1 and a strong base solution with a pH of 12. After 7 days of continuous immersion, no obvious corrosion occurred on the coating surface, and the water contact angle measured after drying remained above 150°. In addition, the anti-corrosion performance of the coating was quantitatively analyzed by electrochemical impedance spectroscopy. The results are as follows: Figure 5 As shown in Figure 2, after immersion in an oil-water composite environment of 3.5 wt% NaCl for 15 days, the low-frequency impedance value of the coating is still as high as 108 Ω·cm 2 , indicating that the prepared superhydrophobic coating has excellent corrosion resistance.

[0063] Performance test of coating prepared in Example 2 Wettability: The wettability of the coating surface in Example 2 was measured using a static contact angle meter (JGW-360A). The results are as follows: Figure 6 and Figure 7 As shown. A drop of deionized water / kerosene was dropped on the coating surface using a 10 μL syringe. The water contact angle was measured to be 160°, while the kerosene was completely spread on the coating surface with a contact angle of 0°. In addition, the coating was 2 / NaHCO 3 ) can also reach a contact angle of more than 150°.

[0064] Scale inhibition performance: The polyurea-based super-wettable anti-scaling coating prepared in Example 2 was immersed in 500 mL of a homemade simulated scaling solution (containing 0.01 mol / L CaCl 2 , 0.01 mol / L NaHCO 3 ) and 500 mL of oil-water composite scaling solution (containing 0.01 mol / L CaCl 2 , 0.01 mol / L NaHCO 3 , 5 wt% kerosene), and the scale inhibition performance test was carried out under simulated working conditions of 60℃ water bath and 125 rpm magnetic stirring. After 24 hours of continuous testing, the scale amount reached 0.23 mg / cm 2 Compared with the pure coating sample, the prepared polyurea-based super-wetting anti-scaling coating showed a negative mass growth phenomenon in both test environments, which was attributed to the mass loss caused by the continuous release of antiscalant by the slow-release filler in the coating. The crystal structure of scale on the coating surface was further characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), such as Figure 8 and Fig. 9 The results show that in the homemade simulated scaling liquid, the calcium carbonate scale on the surface of the polyurea-based super-wetting anti-scaling coating presents a peculiar flower-like chelate state, which is the result of the slow-release scale inhibitor. In the oil-water composite environment, almost no calcium carbonate crystals are formed on the coating surface, and its surface calcium content is only 5.63 wt%, indicating that the super-wetting coating has excellent scale inhibition performance in the oil-water mixed environment.

[0065] Mechanical durability test: The wear resistance of the coating samples was evaluated using a TABER wear tester (JST-3393). During the experiment, 1000-grit sandpaper was used as an abrasive and the test was performed under a constant load of 250 g. After 500 wear cycles, the water contact angle of the prepared polyurea-based superwettable anti-fouling coating remained at 152°, while the oil contact angle remained stable at 0°. When the wear cycle increased to 1000 times, the coating still maintained high hydrophobicity (>140°) and super oleophilic properties (oil contact angle = 0°), indicating that the coating has excellent mechanical stability.

[0066] Corrosion resistance: The prepared coating was titrated using an acid-base solution with a pH of 1 to 14. The results showed that its water contact angle was stably maintained at about 160°. To further evaluate the corrosion resistance of the coating, the samples were immersed in a strong acid solution with a pH of 1 and a strong base solution with a pH of 12. After 7 days of continuous immersion, no obvious corrosion occurred on the coating surface, and the water contact angle measured after drying remained above 150°. In addition, the anti-corrosion performance of the coating was quantitatively analyzed by electrochemical impedance spectroscopy, such as Fig.10 As shown in Figure 2, after immersion in an oil-water composite environment of 3.5 wt% NaCl for 15 days, the low-frequency impedance value of the coating is still as high as 10 6 Ω·cm 2 , indicating that the prepared superhydrophobic coating has excellent corrosion resistance.

[0067] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0068] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a polyurea-based superwetting coating, characterized in that: The following steps are involved: The inorganic titanium source is hydrolyzed to obtain a titanium dioxide gel, the titanium dioxide gel is added to a polyurea resin solution, and a hybrid resin solution is obtained by in-situ hybridization, and a low surface energy modifier is added to the hybrid resin solution for hydrophobic modification to obtain a hydrophobically modified organic-inorganic hybrid resin solution; The nanoparticles and the scale inhibitor are dispersed in water, subjected to a hydrothermal reaction, and the scale inhibitor is grafted onto the nanoparticles. A low surface energy modifier is then added to perform hydrophobic modification, and the mixture is dried to obtain a hydrophobic slow-release nanofiller. After adding prepolymer monomers to water, the pH is adjusted to 7-9, and after stirring, a wall material prepolymer is obtained, and then a scale inhibitor, an emulsifier and a wall material prepolymer are added to an organic solvent and the pH is adjusted to 2-5, in-situ polymerization is performed, and drying is performed to obtain microcapsule powder, and the microcapsule powder is dispersed in anhydrous ethanol, a low surface energy modifier is added for hydrophobic modification, and drying is performed to obtain a hydrophobic microcapsule powder; The hydrophobic sustained-release nanofiller and hydrophobic microcapsule powder are dispersed in an organic-inorganic hybrid resin, uniformly dispersed by ultrasonication, sprayed onto the surface of a substrate using a spray gun, and calcined to obtain a polyurea-based super-wetting coating.

2. The method for preparing a polyurea-based super-wettable anti-fouling coating according to claim 1, characterized in that: The mass percentage of the sustained-release nanofiller in the hydrophobically modified organic-inorganic hybrid resin solution is 1%-10%, and the mass percentage of the microcapsule powder in the hydrophobically modified organic-inorganic hybrid resin solution is 10%-30%.

3. The method for preparing a polyurea-based super-wettable anti-fouling coating according to claim 1, characterized in that: The mass ratio of the inorganic titanium source to the polyurea resin solution is 0.1~1:1~10, and the mass ratio of the low surface energy modifier to the polyurea resin solution is 0.01~0.1:1~10.

4. The method for preparing a polyurea-based super-wet anti-fouling coating according to claim 1, characterized in that: The mass ratio of nanoparticles to scale inhibitor is 0.01~0.1:1~10, the mass ratio of nanoparticles to low surface energy modifier is 0.01~0.1:0.01~0.1, the hydrothermal reaction temperature is 150℃~200℃, and the hydrothermal reaction time is 3h~6h.

5. The method for preparing a polyurea-based super-wettable anti-fouling coating according to claim 1, characterized in that: The mass ratio of the prepolymer monomer to the scale inhibitor and the emulsifier is 1~10:1~10:1~10, and the mass ratio of the prepolymer monomer to the low surface energy modifier is 1~10:0.01~0.

1.

6. The polyurea-based super-wet anti-fouling coating according to claim 1, characterized in that: The nanoparticles are one or more of nano-silicon dioxide, nano-bentonite, nano-titanium dioxide, and nano-graphite, and the scale inhibitor is one or more of ethylenediaminetetraacetic acid, polyepoxysuccinic acid, aminotrimethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, and hydroxyethylenediphosphonic acid.

7. The polyurea-based super-wet anti-fouling coating according to claim 1, characterized in that: The prepolymer monomer is one or more of melamine, formaldehyde solution, triethanolamine, isocyanate, and polyether polyol; the emulsifier is one or more of polyethylene glycol (30), sorbitan fatty acid ester, polyoxyethylene castor oil, polyoxyethylene beeswax, and sodium dodecylbenzene sulfonate.

8. The polyurea-based super-wet anti-fouling coating according to claim 1, characterized in that: The low surface energy modifier is one or more of perfluorooctyl triethoxysilane, dimethyl silicone oil, stearic acid, alkylphenol polyoxyethylene ether, and polyether modified siloxane.

9. The method for preparing the polyurea-based super-wetting coating is characterized in that: The spray gun air pressure is 4 bar ~ 6 bar, the calcination temperature is 150 ℃ ~ 200 ℃, and the calcination time is 10 min ~ 30 min.

10. A polyurea-based super-wetting coating prepared by the preparation method according to any one of claims 1 to 9.

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