A porous super-hydrophobic ceramic material and a method for making the same

Abstract

The application discloses a kind of porous super-hydrophobic ceramic materials with strong weather resistance, high mechanical stability and strong corrosion resistance and a preparation method thereof.The super-hydrophobic surface is prepared by the following method: step one: small pieces of mud are prepared by the method of grouting forming, and the mud is dried at room temperature for half a month and then used;step two: candle soot is collected and mixed uniformly with the mud slurry;step three: the mud slurry and candle soot turbid liquid obtained in step two are uniformly brushed on the mud pieces obtained in step one, and after standing and drying, high-temperature sintering is carried out, and after sintering is completed, the surface of the porous ceramic material obtained is treated with low surface energy;additional step: as an additional step to enhance the super-hydrophobic properties of the surface, nano-particles are ultrasonically dispersed in ethanol at a certain ratio, the nano-particle solution is sprayed into the porous structure of step two by spraying, the nano-particles are stably sintered in the structure by high-temperature sintering, and the surface is treated with low surface energy.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic materials technology, and particularly to a porous superhydrophobic ceramic material and its preparation method. Background Technology

[0002] Wettability is a fundamental property of solid surfaces, characterized by their ability to attract or repel liquids when in contact with them. It is a basic property of solids. Through the study of wettability, researchers have discovered superhydrophobic, superhydrophilic, superoleophobic, and superoleophilic surfaces. Among these superwetting surface studies, superhydrophobic surfaces have become the most studied. Many superhydrophobic phenomena occur in daily life, such as dew rolling on a lotus leaf. By studying these phenomena, it has been determined that when a water droplet contacts a solid surface with a contact angle greater than 150° and a roll-off angle less than 10°, the surface is considered a superhydrophobic surface.

[0003] Ceramic materials have wide applications due to their high mechanical stability, environmental friendliness, resistance to degradation, good thermal conductivity, and good insulation. However, in many applications, higher requirements are placed on the surface properties of ceramic materials. For example, insulators, due to the special nature of their application, ordinary ceramic materials are prone to flashover, leading to power system paralysis and causing huge economic losses. Superhydrophobic surfaces can effectively remove contaminants from the material surface while droplets roll away, thereby reducing the probability of flashover in insulators. Therefore, the preparation of superhydrophobic ceramic materials is necessary and required. Currently, most research focuses on preparing hydrophobic coatings synthesized from polymers on the hydrophilic surface of ceramic insulators. However, polymer coatings have disadvantages such as poor weather resistance, easy degradation, and poor mechanical strength and corrosion resistance, which greatly limit their application. Therefore, the development of a superhydrophobic ceramic-based material with strong weather resistance and good mechanical stability is urgent. Summary of the Invention

[0004] In summary, it is necessary to provide a superhydrophobic ceramic material with good weather resistance and strong mechanical stability, and its preparation method.

[0005] A method for stably containing nanoparticles inside ceramics involves sintering at high temperatures for 1-2 hours, with different sintering temperatures selected for different nanoparticles, to stably sinter the selected nanoparticles in the ceramics and form a micro-nano composite structure on the ceramic surface.

[0006] A method for preparing porous ceramics: The deposited candle soot is mixed with mud in a certain proportion and then evenly brushed onto the surface of the mud block. After drying, it is sintered at 1240℃ for 5-10 minutes. The candle soot will be burned off at a temperature above 550℃, so a porous structure will be formed on the ceramic surface, and finally a ceramic material with a porous surface is obtained.

[0007] A method for preparing a wear-resistant and weather-resistant porous superhydrophobic ceramic surface includes the following steps: Step 1: Obtaining a dried clay block by slip casting; Step 2: Collecting candle soot, mixing the collected candle soot with an appropriate amount of clay slurry, brushing the mixture onto the surface of the clay block, and sintering at high temperature to obtain a porous ceramic material; To enhance the superhydrophobic properties of the material surface, Step 3: Spraying an ethanol nanoparticle solution onto the porous structure of the ceramic and sintering at a certain temperature, followed by fluorination treatment after sintering to obtain a superhydrophobic porous ceramic material.

[0008] The method for preparing porous superhydrophobic ceramic materials provided by this invention has the following advantages: First, by utilizing the difference between the decarburization temperature of candle ash and the porcelain-forming temperature of clay blocks, the candle ash on the surface of the clay blocks can be removed during the ceramic sintering process, thus obtaining a ceramic material with a porous structure in one step. This method is convenient and fast. Second, by controlling the amount of candle ash and the thickness of the coating, the porosity of the porous structure on the ceramic surface can be adjusted, resulting in porous ceramic materials with different mechanical properties and superhydrophobic properties. Third, the clay block preparation method using slip casting is universally applicable, allowing for the preparation of clay blocks of various sizes according to actual needs.

[0009] The porous superhydrophobic ceramic material provided by this invention has the following advantages: First, the prepared superhydrophobic surface has good wear resistance and mechanical stability; Second, it does not contain any polymer materials, which makes the superhydrophobic surface highly weather-resistant, not easy to age and fail, and resistant to acids, alkalis and high temperatures; Third, the prepared superhydrophobic surface has a long service life and excellent superhydrophobic performance.

[0010] In addition, the superhydrophobic surface provided by this invention has the characteristics of readily available raw materials, low cost and easy preparation. Attached Figure Description

[0011] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0012] Figure 1 A SEM image of a superhydrophobic surface according to the present invention;

[0013] Figure 2 Photograph of the surface contact angle of the superhydrophobic and wear-resistant ceramic matrix material of the present invention. Detailed Implementation

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] This invention provides a method for preparing porous superhydrophobic ceramic materials, which includes the following steps:

[0016] Step 1: Using the slurry casting method, pour the purchased slurry into a square pan with dimensions of 20cm×20cm×2cm, let it stand at room temperature, and demold it after the slurry dries and sets to obtain a clay block.

[0017] Step 2: Using a glass slide (30mm x 30mm x 0.17mm) as the substrate, hold and move the slide in the flame of a burning candle to form a uniform layer of black candle soot. The collection time for a single slide is approximately 2-5 minutes. Collect the candle soot from the slide, mix it with the slurry, and evenly brush the turbid liquid onto the surface of the clay block. After allowing it to dry, sinter it at 1240℃ for 5-10 minutes to form porcelain, with a heating rate not exceeding 5℃ / min. After porcelain formation, remove it and fluorinate it to impart a low surface energy, obtaining a superhydrophobic porous ceramic material.

[0018] Additional steps: To improve the superhydrophobicity of the material surface, a nano-silica ethanol solution was prepared. 7-nanometer silica particles were ultrasonically dispersed in the ethanol at a ratio of 0.5 g / 10 ml for 20 minutes. The silica nanoparticle solution was then sprayed onto the porous ceramic structure from step two. The structure was then sintered at 900℃ for 2 hours at a heating rate of 5℃ / min to stably sinter the nanoparticles within the porous structure. The porous ceramic material was then removed and fluorinated using CVD with perfluorodecyltrichlorosilane as the fluorinating agent at 60℃ for 2 hours.

[0019] In step (1), uniformly sized clay blocks can be prepared using a slurry casting method, or a pressing method can be used. This involves using extra-white clay with a water content of 30%, kneading it until soft, pressing it evenly into a square pan, and allowing it to stand before demolding. Alternatively, carbon black can be mixed with clay slurry, stirred evenly, poured into a square pan, and demolded after it has completely dried. The clay blocks can be made according to actual needs.

[0020] The amount of candle ash and mud turbid liquid brushed in step (2) can be adjusted to control the amount and thickness of the porous structure of the ceramic. Preferably, 10 pieces of glass ash deposited with 10g of mud can be mixed and brushed evenly in 2 layers.

[0021] The nanoparticles mentioned in the additional steps can be either silicon dioxide or titanium dioxide; the particle size of the nanoparticles can be 12nm-300nm; and the prepared ethanol solution can be prepared at a ratio of 0.5g / 10ml or 0.5g / 20ml.

[0022] The method of filling nanoparticles is not limited, as long as the porous structure is uniformly filled with nanoparticles. Drop coating, scraping coating, and spraying can be used. Preferably, the filling method is spraying, which is convenient and quick.

[0023] The ultrasonic dispersion time in the additional step is not limited, as long as the nanoparticles are uniformly dispersed in ethanol. Preferably, the ultrasonic time is 20 to 30 minutes.

[0024] Example 1

[0025] A porous ceramic material with dimensions of 2cm × 2cm × 2cm was prepared. 200ml of a 100nm silica-ethanol solution was prepared at a ratio of 0.5g / 10ml. The prepared ethanol solution was sprayed into the structure, sintered at 900℃ for 2 hours, and then fluorinated at 60℃ for 2 hours using CVD to obtain the porous superhydrophobic ceramic material. The ceramic material exhibits a surface contact angle greater than 150°, a roll-off angle of 2°, and excellent superhydrophobic properties.

[0026] Example 2

[0027] This embodiment is basically the same as Embodiment 1, except that 12nm silica particles are used, and an ethanol solution is prepared at a ratio of 0.5g / 20ml. The solution is then sprayed into the structure and sintered at 800℃ for 2 hours. A superhydrophobic ceramic substrate surface is obtained, with a surface contact angle greater than 150° and a roll-off angle of 2°, exhibiting excellent superhydrophobic properties.

[0028] Example 3

[0029] This embodiment is basically the same as Embodiment 1, except that the amount of candle ash is increased, which increases the porosity of the resulting porous ceramic. The resulting superhydrophobic ceramic surface has a contact angle greater than 150° and a roll-off angle of 2°, exhibiting excellent superhydrophobic effect.

[0030] Example 4

[0031] This embodiment is basically the same as Embodiment 1, except that silica particles with a mixed particle size of 12nm-300nm are selected and sintered at 900℃ for 2h, thereby obtaining a superhydrophobic ceramic substrate with a contact angle greater than 150° and a roll-off angle of 2°, and excellent superhydrophobic effect.

[0032] Example 5

[0033] This embodiment is basically the same as embodiment 1, except that the number of coating layers is increased. Ten layers of turbid liquid consisting of candle ash and mud are applied. The resulting superhydrophobic ceramic surface has a contact angle greater than 150° and a roll-off angle of 2°, exhibiting excellent superhydrophobic properties.

[0034] Furthermore, those skilled in the art may make other changes within the spirit of this invention, and of course, all such changes made in accordance with the spirit of this invention should be included within the scope of protection claimed by this invention.

Claims

1. A method for preparing a porous superhydrophobic ceramic material, characterized in that, The method comprises the following steps: Step 1: A slurry is injected into a tray by a slurry casting method, and is left to dry completely to obtain a mud block, which is ready for use; Step 2: Candle soot is deposited, clean glass pieces are placed above a burning candle, candle soot is collected, and the collected candle soot is mixed with a proper amount of slurry and then brushed onto the surface of the dried mud block, and high-temperature sintering is performed to obtain a porous ceramic material on the surface; Step 3: Nanoparticles selected from at least one of silicon dioxide, titanium dioxide and aluminum oxide are ultrasonically dispersed in ethanol at a weight ratio of 1%-20%, the nanoparticle solution is sprayed into the porous structure of the ceramic material by spraying, and high-temperature sintering is performed after being left for half an hour, the nanoparticles are stably sintered on the ceramic by high-temperature sintering, the sintering temperature is in the range of 600-1300℃, and after the sintering is completed, the surface is subjected to low-surface-energy treatment, the low-surface-energy treatment method is hydrophobic treatment of the surface of the ceramic material, and a hydrophobic treatment reagent selected from perfluorodecyltrichlorosilane or perfluorooctyltrichlorosilane is used.

2. The method of claim 1, wherein the porous superhydrophobic ceramic material is prepared by the steps of: The mixing ratio of the candle soot to the slurry is 1:1-2:

1. ​ 3. The method for preparing porous superhydrophobic ceramic materials as described in claim 1, characterized in that, The nanoparticle solution has a nanoparticle size of 12-300 nm, or is a mixture of large-particle-size and small-particle-size nanoparticles.

4. The method for preparing porous superhydrophobic ceramic materials as described in claim 1, characterized in that, The ethanol solution is prepared at a ratio of 0.5 g / 10 mL or 0.5 g / 20 mL.

5. The method for preparing porous superhydrophobic ceramic materials as described in claim 1, characterized in that, The method for filling the nanoparticles includes drop coating, blade coating or spraying.

6. The method for preparing porous superhydrophobic ceramic materials as described in claim 1, characterized in that, The number of layers of the candle soot and the slurry is 10.

7. A porous superhydrophobic ceramic material, characterized in that, The porous super-hydrophobic ceramic material is prepared by the method of any one of claims 1-6.

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