Preparation method of electro-deposition hole-sealing hydrophobic magnesium phosphate cement-based coating
The low-surface energy nano-micro particles were deposited in the magnesium phosphate cement-based coating by electrodeposition method to construct the nano-micro-roughness structure, which solved the problems of wear resistance of organic coatings and complex inorganic coating processes, and achieved durable hydrophobic and corrosion-resistant properties.
Patent Information
- Application Number
- CN202510750587.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-06
- Publication Date
- 2025-08-22
AI Technical Summary
The existing organic hydrophobic coatings have insufficient wear resistance and durability, which are easy to decompose at high temperatures, and the traditional inorganic coating processes are complex and hydrophilic, which requires modification, resulting in poor results in high-temperature environments and large-area applications.
Low surface energy nano-micro particles were deposited in the pores of the magnesium phosphate cement-based coating by electrodeposition method, and a nano-micro-roughness structure was constructed to form a magnesium phosphate cement-based inorganic coating, and a high-adhesion protective layer was formed with the matrix through phosphate chemical bonds.
The durable hydrophobic properties are achieved, and the problem of poor mechanical stability of traditional coatings is solved, forming a dense hydrophobic layer and a passivation film layer to provide wear and corrosion resistance.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of coatings, in particular to a method for preparing an electrodeposited pore-sealed hydrophobic magnesium phosphate cement-based coating. Background Art
[0002] Hydrophobic materials, due to their unique water repellency and self-cleaning properties, have shown broad application prospects in a variety of fields. Depending on the material composition, hydrophobic coatings can be primarily categorized into inorganic and organic hydrophobic coatings. Organic hydrophobic coatings are primarily based on fluoropolymers (such as polytetrafluoroethylene) or silicone resins. Inorganic hydrophobic coatings are typically based on metal oxides (such as silica, zinc oxide) or inorganic nanoparticles. They exhibit excellent high-temperature and weather resistance, as well as chemical stability, and are commonly used in applications such as building facades, solar panels, and power line de-icing.
[0003] Organic coatings (such as fluoropolymers or silicone resins) typically have low hardness and are easily worn by friction, scratches, or external forces, resulting in a decrease in hydrophobicity. Most organic materials are prone to decomposition or oxidation at high temperatures (>200°C), limiting their application in high-temperature environments (such as engine components and industrial equipment). Some organic coatings may swell or degrade in strong acids, strong bases, or organic solvents, affecting long-term performance. High-performance organic materials such as fluoropolymers (such as PTFE) are expensive, increasing the cost of large-scale applications.
[0004] Many inorganic hydrophobic coatings rely on the sol-gel method or high-temperature sintering, which has harsh process conditions and is difficult to coat uniformly over large areas. In addition, inorganic hydrophobic coatings usually adsorb a layer of low-surface-energy molecules on the surface, which is easily worn and affects the durability of the hydrophobic properties.
[0005] Purely inorganic coatings are hydrophilic, but they require surface modification to reduce surface energy and the construction of nano- and micro-roughness structures to achieve hydrophobic properties. Traditional methods for surface hydrophobic modification involve adsorbing a layer of low-surface-energy molecules or applying a hydrophobic organic coating, but these methods are prone to surface shedding, resulting in insufficient durability. Summary of the Invention
[0006] (1) Technical problems solved In view of the shortcomings of the existing technology, the present invention provides a method for preparing an electrodeposited pore-sealed hydrophobic magnesium phosphate cement-based coating, which has good durability.
[0007] (2) Technical solution To achieve the above object, the present invention provides the following technical solution: a method for preparing an electrodeposited pore-sealed hydrophobic magnesium phosphate cement-based coating, wherein the method for preparing the electrodeposited pore-sealed hydrophobic magnesium phosphate cement-based coating is as follows: S1. To burn MgO, KH2PO4, borax as raw materials, add water in a certain ratio, mix to form a slurry coated on the surface of the pretreated substrate, let it stand to form a hardened magnesium phosphate cement coating; S2. Preparation of electrodeposition electrolyte: Dissolve Mg(NO3)2 or Ce(NO3)3 and stearic acid in anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and perform electrodeposition at a constant voltage. S4. After the electrodeposition treatment is completed, remove the sample, clean it with deionized water and anhydrous ethanol ultrasonically, and blow dry it with hot air for later use.
[0008] Furthermore, the mass ratio of dead-burned MgO, KH2PO4, water, and borax in S1 is 6-10g:1g:4.2-5g:0.18-0.22g.
[0009] Furthermore, the pretreatment of the substrate in S1 is as follows: sampling and slicing are performed on a low-carbon steel plate, the surface of the low-carbon steel plate is polished with 400#, 1200#, and 1500# Sic sandpaper respectively, the surface is rinsed with deionized water, and then with ethanol, and the surface is cleaned with ethanol in an ultrasonic cleaner for 3-4 minutes to remove surface impurities, and then dried with hot air for use.
[0010] Furthermore, the standing time in S1 is 1-3 hours.
[0011] Furthermore, the concentration of Mg(NO3)2 or Ce(NO3)3 in the S2 is 0.1-1 mol / L; the concentration of stearic acid is 0.1-1 mol / L.
[0012] Furthermore, the constant voltage in S3 is 10-30V.
[0013] Furthermore, the sedimentation time in S3 is 45-60 minutes.
[0014] Furthermore, the ultrasonic cleaning time in S4 is 3-5 minutes.
[0015] (3) Beneficial technical effects 1. The method provided by the present invention deposits nano- and micro-scale particles with low surface energy within the pores of a magnesium phosphate cement-based coating through a one-step electrodeposition process. These particles not only seal the pores of the magnesium phosphate cement-based coating but also create a nano- and micro-roughness structure, ultimately achieving durable hydrophobicity. Furthermore, the magnesium phosphate cement forms a high adhesion to the substrate through phosphate chemical bonds, and the magnesium phosphate cement liquid phase promotes the formation of a passivating protective layer on the substrate surface. Ultimately, a hydrophobic and wear-resistant magnesium phosphate cement-based inorganic coating is obtained.
[0016] 2. The present invention seals the pores on the surface of the magnesium phosphate cement-based coating through electrodeposition, thereby achieving the construction of a dense nano-micro structure and solving the problem of poor mechanical stability of traditional nano-micro surface structures; and the deposited particles have low surface energy, which can realize the hydrophobicization of the magnesium phosphate cement-based coating, thereby successfully preparing a durable hydrophobic inorganic coating.
[0017] 3. The magnesium phosphate cement-based material of the present invention has a solid-liquid phase structure. The liquid phase has phosphate corrosion-inhibiting ions, which can stimulate the spontaneous formation of a passivation film on the metal surface, and ultimately form a three-layer structure of a dense hydrophobic layer, a cement base layer, and a passivation film layer, providing durable and corrosion-resistant super-hydrophobic properties. DETAILED DESCRIPTION
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0019] Example 1 A method for preparing an electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating comprises the following steps: S1 6g dead-burned MgO, 1g KH2PO4, 0.18g borax as raw materials, then add 4.2g water, mix to form a slurry coated on the pretreated substrate surface, let stand for 1h to form a hardened magnesium phosphate cement coating; The substrate was pretreated as follows: sampling and slicing were performed on a low-carbon steel plate, with the sample size of 10 mm × 10 mm × 5 mm; the surface of the low-carbon steel plate was polished with 400#, 1200#, and 1500# SiC sandpaper, respectively; the surface was rinsed with deionized water, then rinsed with ethanol, and then cleaned with ethanol in an ultrasonic cleaner for 3 minutes to remove surface impurities, and then dried with hot air for later use; S2. Preparation of electrodeposition electrolyte: 20 mL of 0.1 mol / L Mg (NO3) 2, 25 mL of 0.1 mol / L stearic acid was dissolved in 120 mL of anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and electrodeposit at a constant voltage of 10 V for 45 min. S4. After the electrodeposition treatment is completed, remove the sample, ultrasonically clean it with deionized water and anhydrous ethanol for 3 minutes, and blow dry it with hot air for later use. The impedance value of the bare alloy in 3.5wt.% NaCl is about 5000Ω·cm 2 .
[0020] Example 2 A method for preparing an electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating comprises the following steps: S1 10g dead-burned MgO, 1g KH2PO4, 0.22g borax as raw materials, then add 5g of water, mix to form a slurry coated on the pretreated substrate surface, let stand for 3h to form a hardened magnesium phosphate cement coating; The substrate was pretreated as follows: sampling and slicing were performed on a low-carbon steel plate, with the sample size of 10 mm × 10 mm × 5 mm; the surface of the low-carbon steel plate was polished with 400#, 1200#, and 1500# SiC sandpaper, respectively; the surface was rinsed with deionized water, then rinsed with ethanol, and then cleaned with ethanol in an ultrasonic cleaner for 4 minutes to remove surface impurities, and then dried with hot air for later use; S2. Preparation of electrodeposition electrolyte: 30 mL of 1 mol / L Ce (NO3) 3, 30 mL of 1 mol / L stearic acid was dissolved in 150 mL of anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and electrodeposit at a constant voltage of 30 V for 60 min. S4. After the electrodeposition treatment is completed, remove the sample, ultrasonically clean it with deionized water and anhydrous ethanol for 5 minutes, and then blow dry it with hot air for later use.
[0021] Example 3 A method for preparing an electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating comprises the following steps: S1 8g dead-burned MgO, 1g KH2PO4, 0.20g borax as raw materials, then add 4.6g water, mix to form a slurry coated on the pretreated substrate surface, let stand for 2h to form a hardened magnesium phosphate cement coating; The substrate was pretreated as follows: sampling and slicing were performed on a low-carbon steel plate, with the sample size of 10 mm × 10 mm × 5 mm; the surface of the low-carbon steel plate was polished with 400#, 1200#, and 1500# SiC sandpaper, respectively; the surface was rinsed with deionized water, then rinsed with ethanol, and then cleaned with ethanol in an ultrasonic cleaner for 3 minutes to remove surface impurities, and then dried with hot air for later use; S2. Preparation of electrodeposition electrolyte: 25 mL of 0.8 mol / L Mg (NO3) 2, 27 mL of 0.6 mol / L stearic acid was dissolved in 130 mL of anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and electrodeposit at a constant voltage of 20 V for 55 min. S4. After the electrodeposition treatment is completed, remove the sample, ultrasonically clean it with deionized water and anhydrous ethanol for 4 minutes, and then blow dry it with hot air for later use.
[0022] Example 4 A method for preparing an electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating comprises the following steps: S1 6g dead-burned MgO, 1g KH2PO4, 0.18g borax as raw materials, then add 4.2g water, mix to form a slurry coated on the pretreated substrate surface, let stand for 1h to form a hardened magnesium phosphate cement coating; The substrate was pretreated as follows: sampling and slicing were performed on a low-carbon steel plate, with the sample size of 10 mm × 10 mm × 5 mm; the surface of the low-carbon steel plate was polished with 400#, 1200#, and 1500# SiC sandpaper, respectively; the surface was rinsed with deionized water, then rinsed with ethanol, and then cleaned with ethanol in an ultrasonic cleaner for 3 minutes to remove surface impurities, and then dried with hot air for later use; S2. Preparation of electrodeposition electrolyte: 30 mL of 1 mol / L Ce (NO3) 3, 30 mL of 1 mol / L stearic acid was dissolved in 150 mL of anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and electrodeposit at a constant voltage of 20 V for 55 min. S4. After the electrodeposition treatment is completed, remove the sample, ultrasonically clean it with deionized water and anhydrous ethanol for 4 minutes, and then blow dry it with hot air for later use. The impedance value of the bare alloy in 3.5wt.% NaCl is about 4500Ω·cm 2 .
[0023] Performance Testing Neutral salt spray resistance test (1200h) and water resistance, water resistance is determined according to GB / T1733-1993; salt spray resistance is tested according to GB / T1771-2007; and the polarization resistance of different samples is tested after immersion in 3.5% NaCl aqueous solution for 12h.
[0024] Table 1: Performance tests.
[0025]
[0026] As can be seen from Table 1, Examples 1-4 of the present invention have good hydrophobicity, durability and corrosion resistance.
[0027] It should be noted that, in this document, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.
[0028] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A method for preparing an electrodeposited pore-sealed hydrophobic magnesium phosphate cement-based coating, characterized in that: The preparation method of the electrodeposition sealing hydrophobic magnesium phosphate cement-based coating is as follows: S1. To burn MgO, KH2PO4, borax as raw materials, add water in a certain ratio, mix to form a slurry coated on the surface of the pretreated substrate, let it stand to form a hardened magnesium phosphate cement coating; S2. Preparation of electrodeposition electrolyte: Dissolve Mg(NO3)2 or Ce(NO3)3 and stearic acid in anhydrous ethanol; S3. Place the magnesium phosphate cement-based coating sample in the electrolyte, connect it to the cathode of a potentiostat, use a platinum sheet as the anode, and perform electrodeposition at a constant voltage. S4. After the electrodeposition treatment is completed, remove the sample, clean it with deionized water and anhydrous ethanol ultrasonically, and blow dry it with hot air for later use.
2. The method for preparing the electro-deposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The mass ratio of dead-burned MgO, KH2PO4, water, and borax in S1 is 6-10g: 1g: 4.2-5g: 0.18-0.22g.
3. The method for preparing the electro-deposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The pretreatment of the substrate in S1 is as follows: sampling and slicing are performed on a low-carbon steel plate, the surface of the low-carbon steel plate is polished with 400#, 1200#, and 1500# SiC sandpaper respectively, the surface is rinsed with deionized water, then rinsed with ethanol, and cleaned with ethanol in an ultrasonic cleaner for 3-4 minutes to remove surface impurities, and then dried with hot air for use.
4. The method for preparing the electro-deposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The standing time in S1 is 1-3 hours.
5. The method for preparing the electro-deposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The concentration of Mg(NO3)2 or Ce(NO3)3 in the S2 is 0.1-1 mol / L; the concentration of stearic acid is 0.1-1 mol / L.
6. The method for preparing the electro-deposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The constant voltage in S3 is 10-30V.
7. The method for preparing the electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The sedimentation time in S3 is 45-60 min.
8. The method for preparing the electrodeposited pore-sealing hydrophobic magnesium phosphate cement-based coating according to claim 1, characterized in that: The ultrasonic cleaning time in S4 is 3-5 minutes.