Hydrophobic and oleophobic finishing method for alumina fiber product
By combining ethanol cleaning and nanoparticle modification with treatment with self-healing alkane polymers, a micro/nano structure for alumina fiber products was constructed, which solved the problem of unstable hydrophobic properties of alumina fiber products under extreme environments and achieved durable and stable hydrophobic and oleophobic effects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG DONGHENG GUOXIAN NEW MATERIAL CO LTD
- Filing Date
- 2026-03-25
- Publication Date
- 2026-05-12
AI Technical Summary
Existing alumina fiber products treated with fluorinated finishing agents have unstable hydrophobic properties under extreme environments and are easily peeled off under mechanical wear and chemical damage, failing to maintain superhydrophobicity under harsh environments.
Alumina fiber products are cleaned with ethanol and modified with nanoparticles, then high-temperature curing and polymerization coating are performed using self-healing alkane polymers to construct micro/nano structures and form stable hydrophobic and oleophobic surfaces.
This technology enhances the durability and stability of alumina fiber products in extreme environments, improves their hydrophobic and oleophobic properties, extends their service life, and reduces product waste.
Smart Images
Figure CN122013500A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of chemical materials technology, specifically, it relates to a method for finishing alumina fiber products by making them hydrophobic and oleophobic. Background Technology
[0002] Superhydrophobicity refers to solid surfaces that possess both superhydrophobicity and superoleophobicity. As a special interfacial property, superhydrophobicity has been widely studied due to its remarkable liquid-repellent function and its enormous application potential in daily life and industry. Many examples in nature demonstrate superhydrophobicity and superoleophobicity. The most famous example is the lotus effect, which remains clean despite growing in mud. Researchers first elucidated the mechanism of the "lotus effect," attributing its water repellency to the combination of microscopic and nanoscopic surface structures, as well as a dense layer of hydrophobic waxy material on the surface. Other natural examples of superhydrophobicity include giant root leaves, rice leaves, and rose petals. Besides plants, some insects have also been found to have superhydrophobic surfaces, such as the legs of water striders, the wings of butterflies, and cicadas. Based on this, various biomimetic materials are continuously being researched and applied in various industries.
[0003] Alumina fiber is a high-temperature resistant, high-strength, breathable, porous material that is a leader in both military and civilian applications. Due to its unique properties, such as self-cleaning, antifouling, anti-icing, liquid separation, and corrosion resistance, superhydrophobic alumina fiber products are used in various fields. Double-hydrophobic alumina fiber products are suitable for various harsh environments, mitigating the degree of environmental damage, improving underwater applications, achieving high-temperature flame retardancy, and protecting personnel and equipment.
[0004] Currently, the preparation of superhydrophobic surfaces mainly focuses on using fluorinated finishing agents to reduce the surface energy of materials. Fluorine has a small atomic radius and high electronegativity, and can form high-strength and highly polarized CF bonds with carbon atoms. However, the intermolecular forces of polymers containing CF bonds are relatively weak, which results in very low surface energy of fluorinated polymers. Therefore, using fluorinated finishing agents can reduce the surface energy of fibers, and the hydrophobic effect of fabrics treated with fluorinated finishing agents can be greatly improved. However, even so, fluorinated finishing agents cannot be used as a solution to the unstable liquid repellency of rough textured surfaces. In addition to the harm to human health and the environment caused by fluorinated finishing agents, materials treated with fluorinated finishing agents cannot maintain hydrophobic stability in extreme environments, such as chemical damage from acids, alkalis, salts, and heavy oils. Furthermore, fluorinated surfaces can be peeled off during mechanical wear and impact in the external environment. Therefore, improving the durability of textured surfaces is crucial for the hydrophobic properties of materials. Summary of the Invention
[0005] To address the aforementioned problems and technical deficiencies, this application adopts the following technical solution: a method for finishing alumina fiber products by removing hydrophobicity and oleophobicity, comprising the following steps: Ethanol is used to clean the surface of the fiber to remove impurities, and the functional groups of the alumina fiber products are activated. Preparation of nanoparticle-modified alumina fiber products: In-situ growth of nanomaterials on alumina fiber products; High-temperature curing and polymer coating of products are achieved using self-healing alkyl polymers.
[0006] Preferably, the surface cleaning includes: The alumina fiber product was completely immersed in an ethanol solution and treated with constant temperature ultrasonic assisted treatment at 40℃±5℃ for 20min±5min, with the ultrasonic power set to 80-100W. After treatment, rinse 2-3 times with deionized water and pre-dry in a vacuum drying oven at 60℃±5℃ for 15 minutes to thoroughly remove impurities from the fiber surface and simultaneously activate the hydroxyl functional groups on the fiber surface to form uniform anchoring points.
[0007] Preferably, the in-situ growth is achieved by using TiO2-SiO2 composite nanoparticles, which are ultrasonically dispersed and deposited on the fiber surface. The composite nanoparticles are then cured at a preset temperature, followed by washing and drying to obtain nanoparticle-modified alumina fiber products.
[0008] Furthermore, the average particle size of the composite nanoparticles is 20-50 nm, and the dispersion solvent is a mixture of deionized water and anhydrous ethanol in a volume ratio of 3:1.
[0009] Furthermore, the generation of the nanoparticle-modified alumina fiber product includes: The composite nanoparticle mixture was placed in an ultrasonic disperser and dispersed at 100W power for 30 minutes to form a uniform, non-agglomerated nano-dispersion. The activated alumina fiber product is completely immersed in the dispersion solution and kept at a constant temperature of 45℃±5℃ for 25min±5min. After taking it out, the excess dispersion solution is drained, and it is first pre-cured at a low temperature of 65℃±5℃ for 15min, and then heated to a high temperature of 90℃±5℃ for 25min to achieve in-situ growth and bonding of nanoparticles on the fiber surface. After curing, the product is washed three times with deionized water to remove unbonded free nanoparticles, and then vacuum dried at 70°C to constant weight to obtain nanoparticle-modified alumina fiber products.
[0010] Preferably, the high-temperature curing and polymerization coating comprises: High-pressure airless spraying is used to uniformly spray the compound polymer solution onto the surface of the modified alumina fiber product. The spraying thickness is controlled at 6-8μm to ensure full coverage of the coating without any missed areas. After spraying, the polymer is preheated at 80℃±5℃ for 20 minutes to allow it to initially crosslink and solidify. Then, the temperature is raised to 120℃±10℃ for high-temperature curing for 45 minutes±5 minutes. After curing, the product is naturally cooled to room temperature to obtain a double-hydrophobic alumina fiber product.
[0011] Preferably, the ethanol content of the cleaned fiber product is 2%-5%, and the selected nanoparticles are one or more of TiO2, SiO2 and ZIF-8, with the nanoparticle content being 2%-5%. The selected organic polymer is one or more of polymethylhydrosiloxane, polymethylsiloxane, and pure acrylic emulsion; Add a small amount of silane coupling agent KH-550, which is 1% of the total polymer mass, to improve the bonding force between the coating and the nanolayer. The solid content is controlled at 10%±1%.
[0012] Preferably, the specific characterization steps for the hydrophobic properties of the alumina fiber product are as follows: Cut a 10cm×5cm regular fiber sample, ensuring that the surface is free of wrinkles and damage, and place it in a constant temperature and humidity environment of 25℃±1℃ and 50%±5% for 24 hours before testing; A video optical contact angle meter was used to test water droplets and n-hexadecane oil droplets respectively. The droplet volume was controlled at 5 μL. Five different test points were selected for each sample, and the average value was taken. After finishing, the hydrophobic contact angle of the product is ≥152°, the oleophobic contact angle is ≥135°, the water droplet roll-off angle is ≤5°, the oil droplet roll-off angle is ≤8°, the contact angle decay rate is ≤5% after baking at 150℃ for 24 hours, the abrasion resistance is ≥100 times, and the dual hydrophobic properties do not decrease significantly.
[0013] Compared to existing technologies, the beneficial effects of this application are as follows: (1) This application achieves superhydrophobicity by constructing micro / nano structures on the surface of alumina fibers, selecting appropriate nanomaterials and polymer coating materials, and under optimal process parameters; (2) This application utilizes the combination of nanomaterials and organic polymers to construct micro / nano structures on the surface of the product, thereby achieving the hydrophobic and oleophobic functions of the fiber product, which can resist the performance degradation caused by its use in extreme harsh environments and improve its economic practicality. (3) This application grows nanostructures in situ on the surface of fiber products, which improves their strength and extends their service life. The use of organic polymers for curing coating can effectively protect the surface of the product and give the fiber product low surface energy. The combination of the two constructs micro / nano structures, which enables the fiber product to obtain dual hydrophobicity, reduce product waste, increase service life and reduce energy consumption, and has broad application prospects. Attached Figure Description
[0014] In the attached diagram: Figure 1 This is a schematic diagram of the method steps in an embodiment of this application; Figure 2 This is a schematic diagram of the surface wetting properties of an alumina fiber product without double hydrophobic treatment according to an embodiment of this application. Figure 3 This is a schematic diagram of the surface wetting properties of the alumina fiber product after double hydrophobic treatment according to an embodiment of this application. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments. Generally, the components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations.
[0016] Examples, such as Figure 1 As shown, a method for finishing alumina fiber products by making them hydrophobic and oleophobic includes the following steps: Ethanol is used to clean the surface of the fiber to remove impurities, and the functional groups of the alumina fiber products are activated. Surface cleaning includes: The alumina fiber product was completely immersed in an ethanol solution and treated with constant temperature ultrasonic assisted treatment at 40℃±5℃ for 20min±5min, with the ultrasonic power set to 80-100W. After treatment, rinse 2-3 times with deionized water and pre-dry in a vacuum drying oven at 60℃±5℃ for 15 minutes to thoroughly remove impurities from the fiber surface and simultaneously activate the hydroxyl functional groups on the fiber surface to form uniform anchoring points.
[0017] Unlike conventional high-concentration ethanol which only cleans, low-concentration ethanol avoids damage to the fiber matrix, ultrasound assistance ensures deep cleaning of pores, and hydroxyl activation sites enable subsequent nanoparticles to achieve chemical bonding rather than physical adsorption.
[0018] Preparation of nanoparticle-modified alumina fiber products: In-situ growth of nanomaterials on alumina fiber products; In-situ growth involves using TiO2-SiO2 composite nanoparticles, which are ultrasonically dispersed and deposited on the fiber surface. The composite nanoparticles are then cured at a preset temperature, followed by washing and drying to obtain nanoparticle-modified alumina fiber products.
[0019] The average particle size of the composite nanoparticles is 20-50 nm, and the dispersion solvent is a mixture of deionized water and anhydrous ethanol in a volume ratio of 3:1.
[0020] The production of nanoparticle-modified alumina fiber products includes: The composite nanoparticle mixture was placed in an ultrasonic disperser and dispersed at 100W power for 30 minutes to form a uniform, non-agglomerated nano-dispersion. The activated alumina fiber product is completely immersed in the dispersion solution and kept at a constant temperature of 45℃±5℃ for 25min±5min. After taking it out, the excess dispersion solution is drained, and it is first pre-cured at a low temperature of 65℃±5℃ for 15min, and then heated to a high temperature of 90℃±5℃ for 25min to achieve in-situ growth and bonding of nanoparticles on the fiber surface. After curing, the product is washed three times with deionized water to remove unbonded free nanoparticles, and then vacuum dried at 70°C to constant weight to obtain nanoparticle-modified alumina fiber products.
[0021] In-situ growth and gradient curing enable nanoparticles to form stable Al-O-Si / Ti chemical bonds with hydroxyl groups on the fiber surface, completely solving the problem of easy detachment of conventional coated nanolayers. At the same time, it constructs a microscopic multi-level rough structure, laying the structural foundation for dual hydrophobic properties. ZIF-8 nanoparticles can serve as an alternative solution to meet different working conditions.
[0022] High-temperature curing and polymer coating of products are achieved using self-healing alkyl polymers.
[0023] High-temperature curing and polymer coatings include: High-pressure airless spraying is used to uniformly spray the compound polymer solution onto the surface of the modified alumina fiber product. The spraying thickness is controlled at 6-8μm to ensure full coverage of the coating without any missed areas. After spraying, the polymer is preheated at 80℃±5℃ for 20 minutes to allow it to initially crosslink and solidify. Then, the temperature is raised to 120℃±10℃ for high-temperature curing for 45 minutes±5 minutes. After curing, the product is naturally cooled to room temperature to obtain a double-hydrophobic alumina fiber product.
[0024] The compounded self-healing polymer has the ability to self-crosslink with silicon-hydrogen bonds. When microcracks appear in the coating, it can be repaired at room temperature. The two-step method of preheating crystallization and high-temperature curing avoids blistering and cracking of the coating. Pure acrylic emulsion can be used as an alternative for low-temperature working conditions. It takes into account both oleophobic properties and flexibility, and completely achieves the synergistic effect of hydrophobic and oleophobic properties.
[0025] The ethanol content for cleaning fiber products is 2%-5%, and the selected nanoparticles are one or more of TiO2, SiO2, and ZIF-8, with a nanoparticle content of 2%-5%. The selected organic polymer is one or more of polymethylhydrosiloxane, polymethylsiloxane, and pure acrylic emulsion; Add a small amount of silane coupling agent KH-550, which is 1% of the total polymer mass, to improve the bonding force between the coating and the nanolayer. The solid content is controlled at 10%±1%.
[0026] The specific characterization steps for the hydrophobic properties of alumina fiber products are as follows: Cut a 10cm×5cm regular fiber sample, ensuring that the surface is free of wrinkles and damage, and place it in a constant temperature and humidity environment of 25℃±1℃ and 50%±5% for 24 hours before testing; A video optical contact angle meter was used to test water droplets and n-hexadecane oil droplets respectively. The droplet volume was controlled at 5 μL. Five different test points were selected for each sample, and the average value was taken. After finishing, the hydrophobic contact angle of the product is ≥152°, the oleophobic contact angle is ≥135°, the water droplet roll-off angle is ≤5°, the oil droplet roll-off angle is ≤8°, the contact angle decay rate is ≤5% after baking at 150℃ for 24 hours, the abrasion resistance is ≥100 times, and the dual hydrophobic properties do not decrease significantly.
[0027] To broaden the application scenarios of alumina fiber products and improve their performance under oil-water mixed conditions, nanoparticles are deposited on the fiber surface and a stable micro / nano rough structure is constructed using alkane organic solvents to achieve anti-wetting and anti-oil staining functions. The specific steps are as follows: First, the fiber products are cleaned and dried; then they are ultrasonically immersed in a nanoparticle suspension for full contact. After cleaning and drying, continue ultrasonic immersion in an alkane solution; After final baking, hydrophobic and oleophobic alumina fiber products can be obtained.
[0028] The prepared sample has a stable structure, the preparation process is simple, the reaction conditions are mild, and it can achieve dual resistance to water droplets and oils, which is economically feasible.
[0029] First, the surface of the treated alumina fiber products can heal itself after damage. Second, the surface of the treated material itself is strong and wear-resistant enough.
[0030] Self-healing materials and robust materials are basically based on porous, rough material surfaces. Hydrophobic nanofillers (liquid or gel) are injected into the porous surface, and the energy of the nanofillers and the porous substrate are matched to achieve stable adhesion.
[0031] When a self-healing material is subjected to chemical or mechanical damage, low surface energy substances in the system will migrate or capillary action to the damaged area to restore the liquid-repellent function of its surface. The robust material itself has strong resistance to wear and impact. After the outermost layer is scratched off, the superhydrophobic medium embedded inside the medium can maintain most of the small deformations, and the exposed medium surface has the liquid repellency of the original medium.
[0032] The specific steps of the super-sparse treatment method are as follows: 5% TiO2 was ultrasonically dispersed in ethanol for 30 minutes. The activated alumina fiber product was then immersed in the solution and ultrasonically dispersed for another 30 minutes. The product was then removed and dried at 50°C. Subsequently, polymethylsiloxane component A and component B were mixed in a 5:1 ratio and sprayed onto the surface of the fiber product. The product was then cured and dried at 80°C.
[0033] like Figure 2 As shown, untreated fiber products are instantly wetted upon contact with water droplets, with a contact angle of 0°, while hydrophobically treated fiber products are not wetted upon contact with water droplets. Figure 3 As shown, the contact angle is 150°, achieving superhydrophobic properties.
[0034] The specific steps of the double-sparse treatment method are as follows: 5% SiO2 was ultrasonically dispersed in an aqueous solution for 30 minutes. The activated alumina fiber product was then immersed in the solution and ultrasonically dispersed for another 30 minutes. The product was then removed and dried at 50°C. After drying, polymethylhydrosiloxane was sprayed onto the product, preheated at 150°C, and cured at 200°C to form a film that achieved dual hydrophobic properties.
[0035] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications, improvements, and substitutions without departing from the concept of this application, and these all fall within the protection scope of this application.
Claims
1. A method for finishing alumina fiber products by making them hydrophobic and oleophobic, characterized in that, Includes the following steps: Ethanol is used to clean the surface of the fiber to remove impurities, and the functional groups of the alumina fiber products are activated. Preparation of nanoparticle-modified alumina fiber products: In-situ growth of nanomaterials on alumina fiber products; High-temperature curing and polymer coating of products are achieved using self-healing alkyl polymers.
2. The method for finishing alumina fiber products as described in claim 1, characterized in that, The surface cleaning includes: The alumina fiber product was completely immersed in an ethanol solution and treated with constant temperature ultrasonic assisted treatment at 40℃±5℃ for 20min±5min, with the ultrasonic power set to 80-100W. After treatment, rinse 2-3 times with deionized water and pre-dry in a vacuum drying oven at 60℃±5℃ for 15 minutes to thoroughly remove impurities from the fiber surface and simultaneously activate the hydroxyl functional groups on the fiber surface to form uniform anchoring points.
3. The method for finishing alumina fiber products as described in claim 1, characterized in that, The in-situ growth process involves using TiO2-SiO2 composite nanoparticles, which are ultrasonically dispersed and deposited onto the fiber surface. The composite nanoparticles are then cured at a preset temperature, followed by washing and drying to obtain nanoparticle-modified alumina fiber products.
4. The method for finishing alumina fiber products as described in claim 3, characterized in that, The composite nanoparticles have an average particle size of 20-50 nm, and the dispersion solvent is a mixture of deionized water and anhydrous ethanol in a volume ratio of 3:
1.
5. The method for finishing alumina fiber products as described in claim 4, characterized in that, The generation of the nanoparticle-modified alumina fiber product includes: The composite nanoparticle mixture was placed in an ultrasonic disperser and dispersed at 100W power for 30 minutes to form a uniform, non-agglomerated nano-dispersion. The activated alumina fiber product is completely immersed in the dispersion solution and kept at a constant temperature of 45℃±5℃ for 25min±5min. After taking it out, the excess dispersion solution is drained, and it is first pre-cured at a low temperature of 65℃±5℃ for 15min, and then heated to a high temperature of 90℃±5℃ for 25min to achieve in-situ growth and bonding of nanoparticles on the fiber surface. After curing, the product is washed three times with deionized water to remove unbonded free nanoparticles, and then vacuum dried at 70°C to constant weight to obtain nanoparticle-modified alumina fiber products.
6. The method for finishing alumina fiber products as described in claim 1, characterized in that, The high-temperature curing and polymerization coating includes: High-pressure airless spraying is used to uniformly spray the compound polymer solution onto the surface of the modified alumina fiber product. The spraying thickness is controlled at 6-8μm to ensure full coverage of the coating without any missed areas. After spraying, the polymer is preheated at 80℃±5℃ for 20 minutes to allow it to initially crosslink and solidify. Then, the temperature is raised to 120℃±10℃ for high-temperature curing for 45 minutes±5 minutes. After curing, the product is naturally cooled to room temperature to obtain a double-hydrophobic alumina fiber product.
7. The method for finishing alumina fiber products as described in claim 1, characterized in that, The ethanol content for cleaning the fiber products is 2%-5%, and the selected nanoparticles are one or more of TiO2, SiO2, and ZIF-8, with a nanoparticle content of 2%-5%. The selected organic polymer is one or more of polymethylhydrosiloxane, polymethylsiloxane, and pure acrylic emulsion; Add a small amount of silane coupling agent KH-550, which is 1% of the total polymer mass, to improve the bonding force between the coating and the nanolayer. The solid content is controlled at 10%±1%.
8. The method for finishing alumina fiber products as described in claim 6, characterized in that, The specific characterization steps for the hydrophobic properties of the aforementioned alumina fiber product are as follows: Cut a 10cm×5cm regular fiber sample, ensuring that the surface is free of wrinkles and damage, and place it in a constant temperature and humidity environment of 25℃±1℃ and 50%±5% for 24 hours before testing; A video optical contact angle meter was used to test water droplets and n-hexadecane oil droplets respectively. The droplet volume was controlled at 5 μL. Five different test points were selected for each sample, and the average value was taken. After finishing, the hydrophobic contact angle of the product is ≥152°, the oleophobic contact angle is ≥135°, the water droplet roll-off angle is ≤5°, the oil droplet roll-off angle is ≤8°, the contact angle decay rate is ≤5% after baking at 150℃ for 24 hours, the abrasion resistance is ≥100 times, and the dual hydrophobic properties do not decrease significantly.