An electric porcelain insulator with a wear-resistant and hydrophobic structure and a preparation method thereof

Abstract

The present invention discloses an electric porcelain insulator with a wear-resistant and hydrophobic structure and a preparation method thereof, comprising the following steps: applying a ceramic precursor solution to the surface of a ceramic substrate of the electric porcelain insulator, followed by drying and sintering to form a microporous ceramic layer; subjecting the electric porcelain insulator with the microporous ceramic layer to a silane coupling agent activation treatment; immersing the electric porcelain insulator activated by the silane coupling agent in a precursor solution containing Zn(NO3)2 and hexamethylenetetramine for reaction, followed by calcination to generate ZnO nanorods on the surface of the microporous ceramic layer; preheating the electric porcelain insulator after generating the ZnO nanorods, immersing it in a hydrophobic solution, followed by drying and microwave curing to form a composite hydrophobic layer; and spraying a coating onto the electric porcelain insulator after the composite hydrophobic layer is formed, followed by curing to form a micro-nano textured layer. The present invention effectively solves the problems of traditional glaze hydrophobic layers being easily detached and having poor wear resistance, and the preparation method is controllable and simple to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of electric porcelain insulators, and in particular relates to an electric porcelain insulator with a wear-resistant and hydrophobic structure and a preparation method thereof. Background Art

[0002] Porcelain insulators are a common type of insulator used in power systems such as high-voltage transmission lines and substations. Traditional porcelain insulators are exposed to the elements outdoors for long periods of time, and their surfaces gradually wear out due to weathering, wear, and surface contamination. In harsh environments, such as those near heavy industrial areas, porcelain insulators are also corroded by acids and salts. As porcelain insulators wear, their surfaces become rough, allowing contaminants such as dust to easily settle on them. When humidity increases, these contaminants form a conductive path with water, degrading insulation performance and increasing the probability of flashover and other faults.

[0003] Traditional porcelain insulators resist wear by utilizing a wear-resistant glaze. The smooth glaze surface reduces the adhesion of contaminants, but due to the glaze's low hydrophobicity, in high-humidity environments, failure to drain the water in time can still lead to reduced insulation performance, causing electrical faults such as flashover and flashover. To improve surface hydrophobicity, traditional hydrophobic porcelain insulators are sprayed with a hydrophobic material. However, spraying the hydrophobic material over the smooth glaze not only removes the wear resistance provided by the glaze, but also reduces the coating's adhesion due to the smooth glaze's low surface roughness. Furthermore, UV radiation and wear during operation can easily cause the hydrophobic layer to crack or even fall off, resulting in a loss of hydrophobicity. This makes it impossible to simultaneously meet the requirements of wear resistance and hydrophobicity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology, provide an electric porcelain insulator with a wear-resistant and hydrophobic structure and a preparation method thereof, and solve the problems of the traditional hydrophobic electric porcelain insulator having a hydrophobic layer that is not wear-resistant and easy to fall off.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A method for preparing an electric porcelain insulator with a wear-resistant and hydrophobic structure comprises the following steps:

[0007] (1) Coating a ceramic precursor solution on the surface of a ceramic substrate of an electrical porcelain insulator, and then drying and sintering to form a microporous ceramic layer;

[0008] (2) subjecting the electric porcelain insulator having the microporous ceramic layer to a silane coupling agent activation treatment; the activation treatment comprises immersing the electric porcelain insulator in a silane coupling agent solution, followed by drying and annealing;

[0009] (3) Immersing the ceramic insulator activated with a silane coupling agent in a precursor solution containing Zn(NO3)2 and hexamethylenetetramine for reaction, followed by calcination to generate ZnO nanorods on the surface of the microporous ceramic layer;

[0010] (4) preheating the porcelain insulator after the ZnO nanorods are generated, immersing it in a hydrophobic solution, and then drying and microwave curing it to form a composite hydrophobic layer; the hydrophobic solution is a mixture of silane, nano-TiO2 and anhydrous ethanol;

[0011] (5) Spraying a coating onto the electric porcelain insulator after forming the composite hydrophobic layer, and then curing the coating to form a micro-nano texture layer; the coating is a mixture of hydrophobic particles, silicone resin and ethyl acetate, and the hydrophobic particles are hydrophobic aluminum oxide or hydrophobic SiO2.

[0012] As a further improvement, the ceramic substrate in step (1) is an unglazed sintered ceramic material.

[0013] As a further improvement, the ceramic precursor solution in step (1) is an alumina precursor solution, which includes an aluminum salt, a stabilizer and a gelling agent, the concentration of the aluminum salt is 0.5-2.0 mol / L, the molar ratio of the stabilizer to the aluminum salt is 1:1 to 1:2, and the amount of the gelling agent added is 1-5% of the total mass of the solution.

[0014] As a further improvement, the sintering temperature in step (1) is 900-1400° C., the sintering time is 2-4 hours, and the thickness of the microporous ceramic layer after sintering is 1-3 mm.

[0015] As a further improvement, in step (2), the porcelain insulator is first immersed in dilute hydrochloric acid for ultrasonic treatment, then cleaned, and then immersed in a silane coupling agent solution; the annealing is performed at 150-200° C. for 1-2 hours.

[0016] As a further improvement, in step (3), the molar ratio of Zn(NO3)2 to hexamethylenetetramine is 1:1, and the pH value of the solution is 9-10; the reaction is carried out at 90-120°C for 5-8h, and the calcination is carried out at 300-500°C for 1-2h.

[0017] As a further improvement, the hydrophobic solution in step (4) is a mixture of 1-5 parts by mass of silane, 20-25 parts by mass of PDMS, 5-8 parts by mass of nano-TiO2 and 65-75 parts by mass of anhydrous ethanol; and the immersion is carried out under a vacuum environment of 0.1-0.5 MPa for 2-4 hours.

[0018] As a further improvement, the curing in step (5) adopts step-by-step temperature curing: keeping warm at 80°C for 0.5-1h and keeping warm at 120°C for 1-2h.

[0019] The present invention provides an electric porcelain insulator with a wear-resistant and hydrophobic structure prepared by the preparation method. The electric porcelain insulator comprises: a ceramic substrate, a microporous ceramic layer covering the surface of the ceramic substrate, a composite hydrophobic layer attached to the microporous ceramic layer, and a micro-nano textured layer on the surface of the composite hydrophobic layer; the surface of the microporous ceramic layer has ZnO nanorods, and the ZnO nanorods are connected in series with the microporous ceramic layer, the composite hydrophobic layer and the micro-nano textured layer.

[0020] As a further improvement, the microporous ceramic layer has a pore size range of 1-10 μm and a porosity of 40-60%; the ZnO nanorods have a diameter of 50-150 nm and a length of 4-7 μm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The electric porcelain insulator of the present invention is an electric porcelain insulator with a wear-resistant and hydrophobic structure. By combining a microporous ceramic layer, a hydrophobic layer of a composite hydrophobic material and a micro-nano textured layer, the electric porcelain insulator has multiple hydrophobic properties and multiple wear resistances.

[0023] Microporous ceramics give electric porcelain insulators excellent wear resistance and corrosion resistance. The microporous ceramic structure will not affect the insulating properties of the electric porcelain insulator, and the microporous structure of the microporous ceramic layer also has a certain hydrophobic effect. The wear-resistant hydrophobic structure improves the adhesion of the coating through the combined action of the microporous structure and the nanorod structure. The composite hydrophobic material and the micro-nano textured layer can better adhere to the microporous ceramic layer. Compared with the smooth glaze surface, the rough microporous ceramic surface can provide better support for the surface coating to complete the hydrophobic work. The double hydrophobic coating improves the overall hydrophobicity of the structure. In addition, the porosity and pore size of the microporous structure can be controlled within a certain range to meet standardized production requirements.

[0024] The hydrophobic layer of a conventional glazed insulator has a contact angle of less than 90° after friction, failing to maintain hydrophobicity. However, Example 1 of the present invention maintained a contact angle of 120° after the friction test, demonstrating the superiority of the structure. Porcelain insulators with a wear-resistant, hydrophobic structure maintain hydrophobicity even in harsh environments, reducing the frequency of flashover and flashover, while ensuring the insulation performance of the porcelain insulators. The wear-resistant and corrosion-resistant microporous ceramic structure also extends the service life of the porcelain insulators, making them suitable for harsh working environments with high hydrophobicity requirements.

[0025] The invention effectively solves the problems of easy shedding and poor wear resistance of the traditional glaze hydrophobic layer, and the preparation method is controllable and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a process flow chart for preparing the electric porcelain insulator with a wear-resistant and hydrophobic structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the wear-resistant and hydrophobic structure of the electric porcelain insulator with a wear-resistant and hydrophobic structure of the present invention, wherein the reference numerals are as follows: 1. ceramic substrate; 2. microporous ceramic layer; 3. composite hydrophobic layer; 4. nanorods; 5. micro-nano texture layer;

[0029] Figure 3 This is a hydrophobic test diagram of a porcelain insulator sample with a wear-resistant and hydrophobic structure prepared in Example 1;

[0030] Figure 4 This is a hydrophobic test diagram of the electric porcelain insulator sample with a wear-resistant and hydrophobic structure prepared in Example 1 after the wear-resistance test;

[0031] Figure 5 This is a hydrophobic test diagram of a sample of an ordinary smooth glazed porcelain insulator. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0034] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0035] like Figure 2 The present invention discloses an electric porcelain insulator with a wear-resistant and hydrophobic structure, comprising a ceramic substrate, a microporous ceramic layer covering the surface of the ceramic substrate, a composite hydrophobic layer attached to the microporous ceramic layer, and a micro-nano textured layer on the surface of the composite hydrophobic layer. The surface of the microporous ceramic layer comprises a support structure composed of nanorods, which connect the microporous ceramic layer, the composite hydrophobic layer, and the micro-nano textured layer in series.

[0036] In some embodiments, the ceramic substrate is an unglazed sintered ceramic material. After the ceramic substrate of the electric porcelain insulator is solidified, it is directly sintered without glazing.

[0037] The microporous ceramic layer is composed of a wear-resistant ceramic, which can be prepared using a variety of methods, including solution-gel method, ceramic slurry method, powder metallurgy method, and compression molding method. The microporous ceramic layer is made of a wear-resistant ceramic such as alumina ceramic or silicon carbide ceramic.

[0038] In some embodiments, the microporous ceramic layer is prepared using a sol-gel method. First, an alumina precursor solution (porous precursor material) is prepared and coated on the surface of the ceramic substrate. The solution is then dried and the ceramic film thickness is controlled to approximately 1-3 mm through multiple coatings. Finally, the solution is sintered to obtain the microporous alumina ceramic layer.

[0039] In some embodiments, the concentration of aluminum salt (e.g., aluminum nitrate) in the alumina precursor solution is 0.5-2.0 mol / L, the molar ratio of stabilizer (e.g., citric acid) to aluminum salt is 1:1 to 1:2, and the amount of gelling agent (e.g., polyvinyl alcohol) added is 1-5% of the total solution mass. The sintering temperature is 900-1400°C (preferably 1300°C) for 2-4 hours. The sintered ceramic membrane has a thickness of 1-3 mm, a pore size range of 1-10 μm, and a porosity of 40-60%.

[0040] The surface of the microporous ceramic layer is activated by a silane coupling agent to form a stable Si-O-Al covalent bond on the surface, thereby providing chemical fixation for the surface coating.

[0041] In some embodiments, the surface of the microporous ceramic layer is activated by a silane coupling agent, comprising the following steps:

[0042] Step 1: Soak the insulator with a microporous ceramic layer in 1% dilute hydrochloric acid and ultrasonically treat it for 5-20 minutes using an ultrasonic cleaning machine. Use an alkaline solution to neutralize the residual acid. Then, use deionized water to thoroughly rinse it and finally dry it.

[0043] Step 2: Prepare a solution containing 1-5 wt% of silane coupling agent KH550, the solvent is anhydrous ethanol, and adjust the pH value to 5-6 by adding deionized water;

[0044] Step 3: Immerse the porcelain insulator obtained in step 1 in the solution obtained in step 2 for 10-30 minutes;

[0045] Step 4: Place the electric porcelain insulator obtained in step 3 into a vacuum drying oven, dry it at 80-100° C. for 30-60 minutes, and then anneal it at 150-200° C. for 1-2 hours to form Si-O-Al covalent bonds.

[0046] The microporous ceramic layer has a support structure formed by nanorods on its surface, which together with the microporous ceramic structure provide mechanical fixation for the surface coating.

[0047] In some embodiments, the nanorods are ZnO nanorods, with a diameter of 50-150 nm and a length of 4-7 μm. The nanorods are prepared by a hydrothermal method, comprising the following steps:

[0048] Step 1: Zn(NO3)2 and HMTA (hexamethylenetetramine) are mixed in a molar ratio of 1:1 to prepare a precursor solution (ZnO precursor material) with a total concentration of 0.5 mol / L, and the pH value is adjusted to 9-10.

[0049] Step 2: immerse the porcelain insulator whose surface has been activated by a silane coupling agent into the precursor solution obtained in step 1, and place it in a vacuum drying oven at 90-120° C. for reaction for 5-8 hours.

[0050] Step 3: Place the electric porcelain insulator obtained in step 2 into a muffle furnace and heat and calcine at 300-500° C. for 1-2 hours.

[0051] Step 4: Repeat steps 2 to 3 2-3 times.

[0052] The composite hydrophobic layer is formed by coating a layer of hydrophobic material on the microporous ceramic layer. The hydrophobic material is formed by mixing fluorinated silane or organic silane, PDMS, nano-TiO2 and anhydrous ethanol in a certain proportion.

[0053] In some embodiments, the preparation of the composite hydrophobic layer comprises the following steps:

[0054] Step 1: preheating the porcelain insulator after activation treatment with a silane coupling agent and generation of nanorods to 50° C.-60° C.;

[0055] Step 2, immersing the porcelain insulator obtained in step 1 in a hydrophobic solution and placing it in a vacuum environment of 0.1-0.5 MPa, and taking out the porcelain insulator after immersing for 2-4 hours;

[0056] Step 3, shaking the porcelain insulator obtained in step 2 to remove excess solution, and letting it stand at room temperature until the solution is completely dry;

[0057] Step 4: Place the electric porcelain insulator obtained in step 3 in a microwave device for curing for 1-5 minutes.

[0058] Step 5: Repeat steps 2 to 4 2 to 4 times to ensure that the hydrophobic material in the pores is evenly coated.

[0059] In some embodiments, the hydrophobic solution in step 2 is a mixture of silane, nano-TiO2, and anhydrous ethanol. Preferably, PDMS (polydimethylsiloxane) is also added, which is prepared by mixing 1-5 parts by weight of fluorinated silane or organosilane, 20-25 parts by weight of PDMS, 5-8 parts by weight of nano-TiO2 (particle size 1-30 nm), and 65-75 parts by weight of anhydrous ethanol, and uniformly mixing using a magnetic stirrer.

[0060] In some embodiments, the electric porcelain insulator in step 4 is placed in a microwave device for curing, with a microwave power of 300-500W and a curing time of 1-5 minutes.

[0061] In some embodiments, the preparation of the micro-nano textured layer comprises the following steps:

[0062] Step 1: After the composite hydrophobic layer is cured, the electric porcelain insulator is cleaned by an ultrasonic cleaning machine and then dried.

[0063] Step 2: Select one of hydrophobic alumina particles or hydrophobic SiO2 (particle size 1-10 μm) and mix it with silicone resin and ethyl acetate in a certain proportion (10-15wt% of hydrophobic particles, 10-20wt% of silicone resin, 65-80wt% of ethyl acetate, totaling 100%), stir evenly, and perform ultrasonic treatment to better disperse the particles.

[0064] The hydrophobic aluminum oxide or hydrophobic SiO2 can be purchased commercially or subjected to conventional hydrophobic modification, such as silane treatment.

[0065] Step 3: spray the coating (including particle coating) obtained in step 2 evenly on the electric porcelain insulator obtained in step 1, ensuring that the hydrophobic particles are evenly distributed on the surface of the hydrophobic layer.

[0066] Step 4: Place the porcelain insulator obtained in step 3 in a vacuum drying furnace for curing, and perform step-by-step temperature curing (80°C 0.5-1h, 120°C 1-2h) to avoid high-temperature cracking and obtain better coating quality.

[0067] The micro-nano textured layer enhances hydrophobicity through surface roughening (Cassie-Baxter effect). Formed from hydrophobic particles, the micro-nano textured layer is simple to prepare and offers a degree of wear resistance. The thickness of the micro-nano textured layer ranges from 2-6 microns, without affecting the hydrophobicity and other properties of the composite hydrophobic coating, and can achieve dual hydrophobicity.

[0068] refer to Figure 1The method for preparing an electric porcelain insulator having a wear-resistant and hydrophobic structure of the present invention comprises:

[0069] A microporous ceramic layer is added to the unglazed surface of the sintered porcelain insulator. An alumina precursor solution is applied to the surface of the porcelain insulator via a sol-gel process. Repeated spin-coating and drying processes form a wear-resistant ceramic layer blank. The surface is then trimmed. The porcelain insulator is then dried and sintered to produce a wear-resistant microporous structure.

[0070] Clean the surface of the sintered porcelain insulator. Place the porcelain insulator in an ultrasonic cleaning machine and use a detergent to remove surface oil, dust and other contaminants. Rinse the cleaned porcelain insulator with anhydrous ethanol to remove surface moisture, and then dry it.

[0071] The dried surface of the insulator is activated with a silane coupling agent, using a KH550 anhydrous ethanol solution to form stable Si-O-Al covalent bonds on the surface. ZnO nanorods are then grown on the activated microporous ceramic surface to form a supporting structure.

[0072] Fluorinated silane or organic silane, PDMS, nano-TiO2 and anhydrous ethanol are mixed in a certain proportion to prepare a composite hydrophobic material. The treated porcelain insulator is then immersed in the composite hydrophobic solution. Through vacuum impregnation, it is ensured that the solution is evenly attached to the surface of the porcelain insulator and penetrates into the interior. The porcelain insulator is taken out and shaken to remove excess solution on the surface. It is then dried at room temperature and then placed in a microwave device for curing. The impregnation and curing steps are repeated to ensure that the interior of the gap is evenly covered to form a stable composite hydrophobic layer.

[0073] A micro-nano textured layer is sprayed onto the surface of the composite hydrophobic layer. The micro-nano textured layer material is composed of a mixture of hydrophobic aluminum oxide particles or hydrophobic SiO2, silicone resin, and ethyl acetate. The coating is evenly sprayed onto the surface of the porcelain insulator, ensuring uniform particle distribution. The coating is then cured in a vacuum drying oven using a step-by-step temperature ramp.

[0074] Example 1:

[0075] Aluminum nitrate was dissolved in distilled water to prepare a 1.0 mol / L alumina precursor solution. Citric acid was added as a stabilizer (at a molar ratio of 1:1.5 to aluminum salt), and 2% polyvinyl alcohol was added as a gelling agent. The solution was stirred thoroughly and then applied to the surface of a sample (unglazed, sintered ceramic insulator) by dip coating. The sample was dried in a vacuum drying oven and repeatedly coated to a ceramic layer thickness of 2 mm. The sample was then pressurelessly sintered at 1300°C for 3 hours.

[0076] After ultrasonic treatment and cleaning with 1% dilute hydrochloric acid, the sintered specimens were immersed in a 5% KH550 solution (pH 5.5) for 15 minutes. The specimens were then dried in a vacuum oven at 80°C for 45 minutes and annealed at 150°C for 2 hours. A ZnO precursor solution (0.5 mol / L, pH 9.5) was prepared by mixing Zn(NO3)2 and HMTA in a 1:1 ratio. The surface-activated specimens were immersed in this precursor solution and placed in a vacuum oven at 120°C for 7 hours. After cooling, the specimens were placed in a muffle furnace and heated at 400°C for 2 hours.

[0077] A hydrophobic solution was prepared by mixing anhydrous ethanol, PDMS, nano-TiO2, and perfluorooctyltriethylsilane in a ratio of 70:20:8:2. The nano-TiO2 particles were 5 nm in diameter. The treated specimens were preheated to 50°C, immersed in the composite hydrophobic solution, and placed in a vacuum chamber at 0.3 MPa for 4 hours. After removal, the specimens were shaken to remove excess solution, air-dried at room temperature, and then cured in a microwave oven at a power of 300 W for 5 minutes. The hydrophobic coating was repeated once to ensure uniform coverage of the microporous structure, forming a stable composite hydrophobic layer. A particle-containing solution was prepared by mixing hydrophobic SiO2, silicone resin, and ethyl acetate in a ratio of 15:20:65. The hydrophobic SiO2 particles were 5 μm in diameter. The particle-containing solution was evenly sprayed twice onto the specimens after the hydrophobic layer was cured. The specimens were then cured in a vacuum oven using a stepwise temperature ramp (80°C for 1 hour, 120°C for 2 hours).

[0078] The prepared samples were tested for hydrophobicity and wear resistance. Figure 3 This is a hydrophobic test diagram of a porcelain insulator sample with a wear-resistant and hydrophobic structure prepared in Example 1; Figure 4 This is a hydrophobic test diagram of the electric porcelain insulator sample with a wear-resistant and hydrophobic structure prepared in Example 1 after the wear test. The water contact angle was measured using a contact angle meter. The results showed that the contact angle was 135° and the rolling angle was less than 10°, indicating that the sample had excellent hydrophobic properties. The wear resistance test used a 1000-mesh green silicon carbide sandpaper friction experiment. After 500 reciprocating frictions under a load of 50 g, there was no significant decrease in the hydrophobic properties of the sample surface. The contact angle remained at 120° and the rolling angle was 10°, indicating that the sample with the existing wear-resistant and hydrophobic structure had good wear resistance and durability. For comparison, Figure 5 This is a hydrophobic test diagram of a sample of an ordinary smooth glazed porcelain insulator.

[0079] Example 2:

[0080] Aluminum nitrate was dissolved in distilled water to prepare a 1.0 mol / L alumina precursor solution. Citric acid was added as a stabilizer (at a molar ratio of 1:1.5 to the aluminum salt), and 2% polyvinyl alcohol was added as a gelling agent. The solution was stirred thoroughly and then applied to the surface of a sample (unglazed, sintered ceramic insulator) by dip coating. The sample was dried in a vacuum drying oven and repeatedly coated to ensure a ceramic layer thickness of 3 mm. The sample was then pressurelessly sintered at 1300°C for 3 hours.

[0081] After ultrasonic treatment and cleaning with 1% dilute hydrochloric acid, the sintered specimens were immersed in a 5% KH550 solution (pH 5.5) for 15 minutes. The specimens were then dried in a vacuum oven at 80°C for 30 minutes and annealed at 150°C for 1 hour. A ZnO precursor solution (0.5 mol / L, pH 9.5) was prepared by mixing Zn(NO3)2 and HMTA in a 1:1 ratio. The surface-activated specimens were immersed in this precursor solution and placed in a vacuum oven at 120°C for 5 hours. After cooling, the specimens were placed in a muffle furnace and heated at 300°C for 1 hour.

[0082] A hydrophobic solution was prepared by mixing anhydrous ethanol, nano-TiO2, and perfluorooctyltriethylsilane in a ratio of 72:5:23. The nano-TiO2 particles were 5 nm in diameter. The treated specimens were preheated to 50°C, immersed in the composite hydrophobic solution, and placed in a vacuum chamber at 0.3 MPa for 3 hours. After removal, the specimens were shaken to remove excess solution, air-dried at room temperature, and then cured in a microwave oven at 300 W for 2 minutes. The hydrophobic coating was repeated once to ensure uniform coverage of the microporous structure, forming a stable composite hydrophobic layer. A particle-containing solution was prepared by mixing hydrophobic SiO2, silicone resin, and ethyl acetate in a ratio of 15:20:65. The hydrophobic SiO2 particles were 5 μm in diameter. This particle-containing solution was evenly sprayed twice onto the cleaned specimens after the hydrophobic layer was cured. The specimens were then cured in a vacuum oven using a stepwise temperature ramp (80°C for 1 hour, 120°C for 2 hours).

[0083] The prepared samples were tested for hydrophobicity and wear resistance. The water contact angle was measured using a contact angle meter. The results showed that the contact angle was 130° and the rolling angle was 10°, indicating that the sample had excellent hydrophobic properties. The wear resistance test used a 1000-mesh green silicon carbide sandpaper friction experiment. After 500 reciprocating frictions under a load of 50 g, there was no significant decrease in the hydrophobicity of the sample surface, and the contact angle remained at 110° and the rolling angle was 18°, indicating that the sample with a wear-resistant and hydrophobic structure had good wear resistance and durability. However, since PDMS was not added to the hydrophobic solution, the performance was poorer than that of Example 1.

[0084] Example 3:

[0085] Aluminum nitrate was dissolved in distilled water to prepare a 1.0 mol / L alumina precursor solution. Citric acid was added as a stabilizer (at a molar ratio of 1:1.5 to the aluminum salt), and 2% polyvinyl alcohol was added as a gelling agent. The solution was stirred thoroughly and then applied to the surface of a sample (unglazed, sintered ceramic insulator) by dip coating. The sample was dried in a vacuum drying oven and repeatedly coated to ensure a ceramic layer thickness of 1 mm. The sample was then pressurelessly sintered at 1300°C for 3 hours.

[0086] After ultrasonic treatment and cleaning with 1% dilute hydrochloric acid, the sintered specimens were immersed in a 5% KH550 solution (pH 5.5) for 15 minutes. The specimens were then dried in a vacuum oven at 80°C for 10 minutes and annealed at 150°C for 1 hour. A ZnO precursor solution (0.5 mol / L, pH 9.5) was prepared by mixing Zn(NO3)2 and HMTA in a 1:1 ratio. The surface-activated specimens were immersed in this precursor solution and placed in a vacuum oven at 120°C for 5 hours. After cooling, the specimens were placed in a muffle furnace and heated at 300°C for 1 hour.

[0087] A hydrophobic solution was prepared by mixing anhydrous ethanol, PDMS, nano-TiO2, and perfluorooctyltriethylsilane in a ratio of 75:20:4:1. The nano-TiO2 particles were 5 nm in diameter. The treated specimens were preheated to 50°C, immersed in the composite hydrophobic solution, and placed in a vacuum chamber at 0.3 MPa for 1 hour. After removal, the specimens were shaken to remove excess solution, air-dried at room temperature, and then cured in a microwave oven at a power of 300 W for 5 minutes. The hydrophobic coating was repeated once to ensure uniform coverage of the microporous structure, forming a stable composite hydrophobic layer. A particle-containing solution was prepared by mixing hydrophobic SiO2, silicone resin, and ethyl acetate in a ratio of 15:20:65. The hydrophobic SiO2 particles were 5 μm in diameter. The particle-containing solution was evenly sprayed twice onto the specimens after the hydrophobic layer was cured. The specimens were then cured in a vacuum oven using a stepwise temperature ramp (80°C for 1 hour, 120°C for 2 hours).

[0088] The prepared samples were tested for hydrophobicity and wear resistance. The water contact angle was measured using a contact angle meter. The results showed that the contact angle was 131° and the rolling angle was less than 10°, indicating that the sample had excellent hydrophobic properties. The wear resistance test used a 1000-mesh green silicon carbide sandpaper friction experiment. After 500 reciprocating frictions under a load of 50 g, there was no significant decrease in the hydrophobicity of the sample surface, the contact angle remained at 110°, and the rolling angle was 15°, indicating that the sample with a wear-resistant and hydrophobic structure had good wear resistance and durability. However, due to the low proportion of nano-TiO2 and perfluorooctyltriethylsilane in the hydrophobic solution, the performance was poorer than that of Example 1.

[0089] Comparative Example 1:

[0090] The difference from Example 1 is that the micro-nano texture layer is omitted and the test is performed after the composite hydrophobic layer is formed. The other steps are the same as those in Example 1.

[0091] Comparative Example 2:

[0092] The difference from Example 1 is that the composite hydrophobic layer is omitted, and the micro-nano texture layer is prepared after the ZnO nanorods are generated. The other steps are the same as in Example 1.

[0093] Comparative Example 3:

[0094] This comparative example is a common waterproofing method, in which a composite hydrophobic layer is directly prepared on a ceramic substrate and then tested. The preparation of the composite hydrophobic layer is the same as in Example 1.

[0095] The test results of the embodiments and comparative examples are listed in the table below:

[0096]

[0097] The rolling angle of Comparative Example 2 is smaller than that of Comparative Example 1 because the surface roughness of Comparative Example 2 is appropriate and the micro-nano texture has a better hydrophobic effect. However, after the grinding test, the surface micro-nano texture and roughness are destroyed. Although it still has a certain degree of hydrophobicity, the rolling angle is greatly increased.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical solution of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing an electric porcelain insulator with a wear-resistant and hydrophobic structure, characterized in that: The following steps are included: (1) Coating a ceramic precursor solution on the surface of a ceramic substrate of an electrical porcelain insulator, and then drying and sintering to form a microporous ceramic layer; (2) subjecting the electric porcelain insulator having the microporous ceramic layer to a silane coupling agent activation treatment; the activation treatment comprises immersing the electric porcelain insulator in a silane coupling agent solution, followed by drying and annealing; (3) Immersing the ceramic insulator activated with a silane coupling agent in a precursor solution containing Zn(NO3)2 and hexamethylenetetramine for reaction, followed by calcination to generate ZnO nanorods on the surface of the microporous ceramic layer; (4) preheating the porcelain insulator after the ZnO nanorods are generated, immersing it in a hydrophobic solution, and then drying and microwave curing it to form a composite hydrophobic layer; the hydrophobic solution is a mixture of silane, nano-TiO2 and anhydrous ethanol; (5) Spraying a coating onto the electric porcelain insulator after forming the composite hydrophobic layer, and then curing the coating to form a micro-nano texture layer; the coating is a mixture of hydrophobic particles, silicone resin and ethyl acetate, and the hydrophobic particles are hydrophobic aluminum oxide or hydrophobic SiO2.

2. The preparation method according to claim 1, characterized in that The ceramic substrate in step (1) is an unglazed sintered ceramic material.

3. The preparation method according to claim 1, characterized in that The ceramic precursor solution in step (1) is an alumina precursor solution, which includes an aluminum salt, a stabilizer and a gelling agent. The concentration of the aluminum salt is 0.5-2.0 mol / L, the molar ratio of the stabilizer to the aluminum salt is 1:1 to 1:2, and the amount of the gelling agent added is 1-5% of the total mass of the solution.

4. The preparation method according to claim 1, characterized in that The sintering temperature in step (1) is 900-1400° C., the sintering time is 2-4 hours, and the thickness of the microporous ceramic layer after sintering is 1-3 mm.

5. The preparation method according to any one of claims 1 to 4, characterized in that Step (2) first immerses the electric porcelain insulator in dilute hydrochloric acid for ultrasonic treatment, then cleans it, and then immerses it in a silane coupling agent solution; the annealing is performed at 150-200° C. for 1-2 hours.

6. The preparation method according to any one of claims 1 to 4, characterized in that In step (3), the molar ratio of Zn(NO3)2 to hexamethylenetetramine is 1:1, and the pH value of the solution is 9-10; the reaction is carried out at 90-120°C for 5-8 hours, and the calcination is carried out at 300-500°C for 1-2 hours.

7. The preparation method according to any one of claims 1 to 4, characterized in that The hydrophobic solution in step (4) is a mixture of 1-5 parts by mass of silane, 20-25 parts by mass of PDMS, 5-8 parts by mass of nano-TiO2 and 65-75 parts by mass of anhydrous ethanol; the immersion is carried out under a vacuum environment of 0.1-0.5 MPa for 2-4 hours.

8. The preparation method according to any one of claims 1 to 4, characterized in that The curing in step (5) is performed by step-by-step temperature rise: 80°C for 0.5-1h, and 120°C for 1-2h.

9. An electric porcelain insulator with a wear-resistant and hydrophobic structure prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The electric porcelain insulator comprises: a ceramic substrate, a microporous ceramic layer covering the surface of the ceramic substrate, a composite hydrophobic layer attached to the microporous ceramic layer, and a micro-nano textured layer on the surface of the composite hydrophobic layer; the surface of the microporous ceramic layer has ZnO nanorods, and the ZnO nanorods are connected in series with the microporous ceramic layer, the composite hydrophobic layer and the micro-nano textured layer.

10. The electric porcelain insulator according to claim 9, characterized in that: The microporous ceramic layer has a pore size range of 1-10 μm and a porosity of 40-60%; the ZnO nanorods have a diameter of 50-150 nm and a length of 4-7 μm.

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