A fluorine-free organic small molecule-based ultrathin superhydrophobic coating and a preparation method thereof
By forming chemical bonds between fluorine-free organic small molecules and the substrate surface, an ultrathin superhydrophobic coating is prepared, which solves the problems of uneven coating thickness and environmental pollution in existing coatings and achieves efficient self-cleaning and oil-water separation performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN UNIV OF TECH
- Filing Date
- 2024-05-31
- Publication Date
- 2026-07-21
AI Technical Summary
Existing superhydrophobic coatings have uneven thickness, are prone to powder shedding, and contain fluoropolymers that pollute the environment and are difficult to control, and the preparation process is complex.
An ultrathin superhydrophobic coating is prepared by using fluorine-free organic small molecules such as amines, epoxides, alkenes and thiols to form effective chemical bonds with the substrate surface and combining them with polydimethylsiloxane.
The prepared superhydrophobic coating has uniform thickness, strong adhesion, is environmentally friendly and stable, has self-cleaning and oil-water separation properties, good durability, and does not affect the original properties of the substrate.
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Figure CN118440527B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of superhydrophobic coating technology, specifically to an ultrathin superhydrophobic coating based on fluorine-free organic small molecules and its preparation method. Background Technology
[0002] Superhydrophobic coatings have become a research hotspot in academia in recent years due to their unique surface wettability. To date, researchers have discovered that many microscopic structures in organisms possess excellent superhydrophobic properties, such as lotus leaves, butterfly wings, red rose petals, and rice leaves. Studies have found that superhydrophobic surfaces have two important characteristics: a water droplet contact angle greater than 150° and a water droplet roll-off angle less than 10°. Based on these characteristics, materials with superhydrophobic surfaces can be widely applied in various fields, such as self-cleaning, corrosion resistance, anti-frost, biomedicine, and oil-water separation.
[0003] Currently, most superhydrophobic coatings are prepared by modifying the surface of substrates such as cotton fabric using micro / nano inorganic particles and fluoropolymers, as illustrated in CN111393942A, CN103753908A, and CN115109447B. These studies used inorganic nano-silica or titanium dioxide particles, fluoropolymers, or fluorinated compounds to prepare superhydrophobic coatings. However, inorganic micro / nano particles struggle to form effective chemical bonds with the substrate and low surface energy materials, resulting in some superhydrophobic coatings being very thick and others exhibiting a "powdering" phenomenon. Furthermore, the polymerization reaction of fluorinated monomers is difficult to control, and free radical side reactions are difficult to suppress, making structural regulation of fluoropolymers challenging. Moreover, fluorinated substances easily pollute soil and groundwater, and toxic fluorine can accumulate in organisms. Therefore, developing a superhydrophobic coating with uniform thickness and environmentally friendly raw materials is of significant research value. Summary of the Invention
[0004] To address the problems existing in the prior art, this invention provides an ultrathin superhydrophobic coating based on fluorine-free organic small molecules and its preparation method. The ultrathin superhydrophobic coating is designed and prepared by utilizing active organic small molecules to achieve effective chemical bonding with the substrate surface.
[0005] To achieve the above objectives, the present invention provides the following technical solution: an ultrathin superhydrophobic coating based on fluorine-free organic small molecules, in parts by mass,
[0006] The mixed solution comprises 20 to 40 parts of an amine compound, 20 to 40 parts of an epoxy compound, and 20 to 40 parts of a solvent;
[0007] The mixed coating comprises 1 to 30 parts of an olefin compound, 1 to 25 parts of polydimethylsiloxane, 1 to 25 parts of an initiator, 1 to 40 parts of a mercapto compound, and 1 to 40 parts of a solvent.
[0008] After immersing the substrate in the mixed solution, the mixed coating is applied to the surface of the immersed substrate material and then dried to obtain an ultrathin superhydrophobic coating on the substrate.
[0009] Furthermore, in the mixed solution, the amine compounds include one or more of ethylamine, propylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, aniline, diphenylamine, pyridine, diethylenetriamine, and triethylenetetramine;
[0010] Epoxy compounds include one or more of the following: ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, cyclohexanediethanol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, and diglycidyl terephthalate.
[0011] Furthermore, in mixed coatings:
[0012] Alkenes include one or more of the following: methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, dodecyl acrylate, cyclohexyl acrylate, benzyl acrylate, and phenyl acrylate.
[0013] Thiol compounds include one or more of the following: ethanethiol, propylene dithiol, butanethiol, pentamethylthiol, hexanethiol, cyclopentanethiol, cyclohexanethiol, octylthiol, decanethiol, dodecylthiol, hexadecylthiol, and octadecylthiol;
[0014] Initiators include azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, potassium persulfate, di-tert-butyl peroxide, cumene hydroperoxide, triphenylphosphine oxide, isopropylthioxanthone, alpha-hydroxyisobutyrophenone, or photoinitiator 907.
[0015] Furthermore, the solvent is selected from tetrahydrofuran, N,N-dimethylformamide, N,N-dimethyl sulfoxide, anhydrous ethanol, methanol, diethyl ether, acetone, ethyl acetate, butyl acetate, cyclohexane, toluene, etc.
[0016] Furthermore, the substrate includes one or more of the following: paper, natural fibers, synthetic fibers, plastics, glass, ceramics, wood, wood-plastic composites, and concrete.
[0017] Furthermore, the mixed coating is applied to the surface of the substrate material after immersion using processes such as soaking, spraying, spin coating, printing, or UV curing.
[0018] This invention also provides a method for preparing an ultrathin superhydrophobic coating based on fluorine-free organic small molecules, the specific steps of which are as follows:
[0019] S1 involves immersing the substrate in a mixed solution with continuous stirring during the immersion process to obtain a pretreated substrate. The mixed solution is obtained by mixing amine compounds, epoxy compounds, and solvents.
[0020] S2 coats a pretreated substrate with a mixed coating, allows it to stand, and dries to obtain an ultrathin superhydrophobic coating.
[0021] Furthermore, in S1, the substrate is immersed in the mixed solution for 1 hour to 24 hours; in S2, the pretreated substrate is covered with the mixed coating, left to stand for 1 hour to 7 hours, and then dried at a temperature of 40°C to 200°C.
[0022] The present invention also provides a product with superhydrophobic function, comprising a substrate and an ultrathin superhydrophobic coating covering the substrate, wherein the ultrathin superhydrophobic coating is the above-mentioned ultrathin superhydrophobic coating or an ultrathin superhydrophobic coating prepared by the above-mentioned preparation method.
[0023] Furthermore, the substrate of the aforementioned product with superhydrophobic function includes one or more of the following: paper, natural fibers, synthetic fibers, plastics, glass, ceramics, wood, wood-plastic composites, and concrete.
[0024] Compared with the prior art, the present invention has at least the following beneficial effects:
[0025] This invention provides an ultrathin superhydrophobic coating based on fluorine-free organic small molecules. It utilizes environmentally friendly, readily reactive, and active fluorine-free organic small molecules, including amine compounds, epoxy compounds, alkene compounds, thiol compounds, and polydimethylsiloxane. In the mixed solution, the epoxy compounds react with the substrate under the catalysis of the amine compounds. The alkene and thiol compounds in the mixed coating react with the epoxy compounds grafted onto the substrate surface, reducing the surface energy of the substrate. Simultaneously, the highly hydrophobic and strongly adhesive polydimethylsiloxane adheres to the substrate surface, further enhancing the hydrophobic properties of the substrate. This results in an ultrathin superhydrophobic coating with effective chemical bonds on the substrate surface. This superhydrophobic coating exhibits excellent self-cleaning and oil-water separation properties. After durability and stability tests, including heavy-duty wear, acid and alkali solution immersion, and ultraviolet radiation, the superhydrophobic coating still demonstrates excellent superhydrophobicity.
[0026] The method for preparing the ultrathin superhydrophobic coating of this invention avoids complex operations such as surface modification of inorganic micro- and nanoparticles and synthesis of fluoropolymers. It specifically selects epoxy compounds as crosslinking agents to form effective chemical bonds between olefin compounds, mercapto compounds and the substrate, tightly binding low surface energy materials with the substrate. Furthermore, because the prepared coating is very thin, it does not affect the original properties of the substrate during the preparation process, including hue, gloss, air permeability and smoothness. The prepared coating also has excellent stability, durability, self-cleaning and oil-water separation properties, and can be widely used to separate immiscible oil-water mixtures. Attached Figure Description
[0027] Figure 1 This invention provides a flowchart for the preparation of an ultrathin superhydrophobic coating based on fluorine-free organic small molecules.
[0028] Figure 2 Schematic diagram of water droplet contact angle measurement on superhydrophobic surfaces provided in all embodiments of the present invention.
[0029] Figure 3 Schematic diagram of water roll-off angle measurement of superhydrophobic surfaces provided in all embodiments of the present invention.
[0030] Figure 4 The results of oil-water separation efficiency test of the superhydrophobic cotton fabric provided in Embodiment 1 of the present invention.
[0031] Figure 5 Scanning electron microscope (SEM) images of the original cotton cloth (a) and superhydrophobic cotton cloth (b) provided in Example 1 of the present invention, the original filter paper (c) and superhydrophobic filter paper (d) provided in Example 2, and the original glass (e) and superhydrophobic glass (f) provided in Example 4. Detailed Implementation
[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0033] This invention provides a method for preparing an ultrathin superhydrophobic coating based on fluorine-free organic small molecules. The implementation steps are as follows: Figure 1 This includes the following steps:
[0034] Step 1: Take 20 to 40 parts of amine compound, 20 to 40 parts of epoxy compound, and 20 to 40 parts of solvent and mix them to obtain a mixed solution.
[0035] Step 2: Immerse the substrate in the mixed solution for 1 to 24 hours, then remove the substrate to obtain the pretreated substrate.
[0036] Step 3: Take 1 to 30 parts of olefin compound, 1 to 25 parts of polydimethylsiloxane, 1 to 25 parts of initiator, 1 to 40 parts of mercapto compound, and 1 to 40 parts of solvent and mix them to obtain a mixed coating.
[0037] Step 4: Using a specific process, the mixed coating is evenly applied to the surface of the pretreated substrate and left to stand for 1 to 7 hours. Then, the substrate with the coating is placed in an oven at 40°C to 200°C to dry, resulting in an ultrathin superhydrophobic coating on the substrate.
[0038] In step 1, the amine and epoxy compounds are first dissolved in an organic solvent, and then the substrate is immersed in the mixed solution with continuous stirring during the immersion process. During immersion, the epoxy compounds in the mixed solution react with the substrate under the catalysis of the amine compounds. The purpose of stirring is to circulate the small molecules participating in the reaction, thereby uniformly dispersing the small molecules in the solvent and accelerating the chemical reaction process.
[0039] Preferably, the amine compound is selected from one or more of ethylamine, propylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, aniline, diphenylamine, pyridine, diethylenetriamine, and triethylenetetramine.
[0040] Preferably, the epoxy compound is selected from one or more of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, cyclohexanediethanol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, and diglycidyl terephthalate.
[0041] Preferably, the solvent is selected from tetrahydrofuran, N,N-dimethylformamide, N,N-dimethyl sulfoxide, anhydrous ethanol, methanol, diethyl ether, acetone, ethyl acetate, butyl acetate, cyclohexane, toluene, etc.
[0042] In step 2, the substrate is immersed in the mixed solution. After 1 to 24 hours, the substrate is removed.
[0043] Preferably, the substrate includes one or more of the following: paper, natural fibers, synthetic fibers, plastics, glass, ceramics, wood, wood-plastic composites, and concrete. Specifically, paper includes filter paper, test paper, writing paper, dictionary paper, and book paper; natural fibers include cotton, linen, silk, and wool; synthetic fibers include polyester, nylon, acrylic, chlorofiber, vinylon, spandex, and polyolefin elastic yarn; and plastics include polyethylene, polypropylene, polyvinyl chloride, polystyrene, and acrylonitrile-butadiene-styrene copolymer, etc.
[0044] In step 3, low surface energy substances, namely olefin compounds, mercapto compounds, and polydimethylsiloxane, are dissolved in an organic solvent, and an initiator is added simultaneously. The olefin compounds and mercapto compounds react with the epoxy compounds grafted onto the substrate surface, reducing the surface energy of the substrate. At the same time, the highly hydrophobic and strongly adhesive polydimethylsiloxane adheres to the substrate surface, further enhancing the hydrophobic properties of the substrate.
[0045] Preferably, the olefin compound is selected from one or more of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, dodecyl acrylate, cyclohexyl acrylate, benzyl acrylate, and phenyl acrylate.
[0046] Preferably, the thiol compound is selected from one or more of ethanethiol, propylene dithiol, butanethiol, pentathiol, hexanethiol, cyclopentanethiol, cyclohexanethiol, octylthiol, decanethiol, dodecylthiol, hexadecylthiol, and octadecylthiol.
[0047] Preferably, the initiators include azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, potassium persulfate, di-tert-butyl peroxide, cumene hydroperoxide, triphenylphosphine oxide, isopropylthioxanthone, alpha-hydroxyisobutyrylbenzene, photoinitiator 907, etc.
[0048] In step 4, the mixed coating obtained in step 3 is uniformly applied to the surface of the soaked substrate material using a specific process, and allowed to stand for 1 to 7 hours. Then, the substrate with the coating is placed in an oven at 40°C to 200°C to dry. The purpose of drying is to evaporate any residual solvent on the substrate surface. The drying time is not limited; the substrate can be dried completely within 1 to 10 hours.
[0049] Preferred specific processes include immersion, spraying, spin coating, printing, UV curing, etc.
[0050] The advantages of this invention are:
[0051] An ultrathin superhydrophobic coating that forms effective chemical bonds with the substrate surface is designed and prepared using environmentally friendly, reactive, and active fluorine-free small organic molecules, namely amines, epoxides, alkenes, thiol compounds, and polydimethylsiloxane. This superhydrophobic coating exhibits excellent self-cleaning and oil-water separation properties, and its preparation process does not affect the original properties of the substrate, including hue, gloss, breathability, and smoothness. Furthermore, after durability and stability tests including heavy-duty wear, acid and alkali solution immersion, and ultraviolet radiation, the superhydrophobic coating still demonstrates excellent superhydrophobicity.
[0052] This avoids complex operations such as surface modification of inorganic micro / nanoparticles and synthesis of fluoropolymers. Epoxy compounds are used as crosslinking agents to form effective chemical bonds between olefins, thiol compounds, and the substrate, tightly binding low surface energy materials to the substrate.
[0053] Example 1:
[0054] Mix 20 parts triethylamine, 40 parts propylene glycol diglycidyl ether, and 40 parts tetrahydrofuran to obtain a mixed solution. Immerse cotton fabric in the mixed solution. After 15 hours, remove the cotton fabric. Mix 30 parts ethyl acrylate, 15 parts polydimethylsiloxane, 2 parts azobisisobutyronitrile, 13 parts hexadecyl mercaptan, and 40 parts tetrahydrofuran to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed substrate material using a spraying process and let it stand for 6 hours. Then, place the cotton fabric coated with the coating in an oven at 200°C and bake for 7 hours to obtain a superhydrophobic cotton fabric.
[0055] The water droplet contact angle and water droplet roll-off angle of the superhydrophobic cotton fabric were measured. A schematic diagram of the water droplet contact angle measurement is shown below. Figure 2 As shown, θ is the angle being measured. A schematic diagram for measuring the rolling angle of a water droplet is shown below. Figure 3 As shown, α is the angle being measured. Tests showed that the superhydrophobic cotton fabric has a water droplet contact angle greater than 150° and a water roll-off angle less than 10°.
[0056] Using superhydrophobic cotton cloth as a filter, and selecting chloroform, n-hexane, and n-decane as representatives of the oil phase, oil-water separation tests were conducted on the superhydrophobic cotton cloth. The test results are as follows: Figure 4 As shown, the oil-water separation efficiency is higher than 98%, indicating that the superhydrophobic cotton fabric has excellent oil-water separation performance.
[0057] Durability and stability tests, including load abrasion, acid and alkali solution immersion, and ultraviolet radiation, were conducted on the superhydrophobic cotton fabric. The fabric still exhibited excellent superhydrophobicity.
[0058] According to GB / T 7974-2002, GB / T 8941-2007, and GB / T 7921-2008, the whiteness, gloss, and color difference of the original cotton fabric and the superhydrophobic cotton fabric were measured respectively. The measurement results are shown in Table 1. Table 1 shows that the whiteness difference between the original cotton fabric and the superhydrophobic cotton fabric is 0.34, and the gloss differences at 20°, 60°, and 75° angles are 0.04, 0.04, and 0.03, respectively, indicating that the whiteness and gloss of the original cotton fabric remain almost unchanged after superhydrophobic treatment. Furthermore, the color difference between the original cotton fabric and the superhydrophobic cotton fabric is 0.56, which is less than 1, making it visually difficult to distinguish the color difference between the two objects. This indicates that after preparing the superhydrophobic coating on the cotton fabric surface, the very thin superhydrophobic coating did not cause any color change.
[0059] Table 1
[0060]
[0061] The microstructure of the original cotton fabric and the superhydrophobic cotton fabric was observed using field scanning electron microscopy, such as... Figure 5 As shown. Figure 5 (a) is a scanning electron microscope image of the original cotton fabric. Figure 5(b) is a scanning electron microscope image of the superhydrophobic cotton fabric. As can be seen from the image, there is no obvious difference between the original cotton fibers and the superhydrophobic cotton fibers, indicating that the superhydrophobic coating prepared on the surface of the cotton fabric is very thin.
[0062] Example 2:
[0063] Mix 40 parts triethylamine, 20 parts propylene glycol diglycidyl ether, and 20 parts tetrahydrofuran to obtain a mixed solution. Immerse filter paper in the mixed solution. After 24 hours, remove the filter paper. Mix 1 part ethyl acrylate, 25 parts polydimethylsiloxane, 25 parts azobisisobutyronitrile, 40 parts hexadecyl mercaptan, and 10 parts tetrahydrofuran to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed filter paper using a spraying process and let it stand for 1 hour. Then, dry the coated filter paper in an oven at 100°C to obtain superhydrophobic filter paper.
[0064] The water droplet contact angle and water droplet roll-off angle of the superhydrophobic filter paper were measured. The tests showed that the water droplet contact angle of the superhydrophobic cotton cloth was greater than 150°, and the water roll-off angle was less than 10°. Using the superhydrophobic filter paper as a filter, and selecting chloroform, n-hexane, and n-decane as oil phases, oil-water separation tests were conducted. The oil-water separation efficiency was higher than 98%, indicating that the superhydrophobic filter paper has excellent oil-water separation performance. Durability and stability tests, including load abrasion, acid and alkali solution immersion, and ultraviolet radiation, were performed on the superhydrophobic filter paper, and it still exhibited excellent superhydrophobicity. According to GB / T 7974-2002, GB / T8941-2007, and GB / T 7921-2008, the whiteness, gloss, and color difference of the original filter paper and the superhydrophobic filter paper were measured respectively. The measurement results are shown in Table 2. Table 2 shows that the whiteness difference between the original filter paper and the superhydrophobic filter paper is 0.13, and the gloss differences at 20°, 60°, and 75° angles are 0, 0.1, and 0.03, respectively. This indicates that the whiteness and gloss of the original filter paper remain almost unchanged after superhydrophobic treatment. Furthermore, the color difference between the original and superhydrophobic filter papers is 0.67, less than 1, making it visually difficult to distinguish the color difference between the two objects. This indicates that even with a very thin superhydrophobic coating on the cotton surface, the color of the coating remains unchanged. The microstructure of the original and superhydrophobic filter papers was observed using a field scanning electron microscope (SEM). Figure 5 (c) and Figure 5 As shown in (d), it can be seen from the figure that there is no obvious difference between the original filter paper fiber and the superhydrophobic filter paper fiber, which also indicates that the superhydrophobic coating prepared on the filter paper surface is very thin.
[0065] Table 2
[0066]
[0067] Example 3:
[0068] Mix 30 parts triethylamine, 40 parts ethylene glycol diglycidyl ether, and 30 parts tetrahydrofuran to obtain a mixed solution. Immerse linen in the mixed solution. After 1 hour, remove the linen. Mix 30 parts isooctyl acrylate, 1 part polydimethylsiloxane, 16 parts azobisisobutyronitrile, 13 parts hexadecyl mercaptan, and 40 parts tetrahydrofuran to obtain a mixed coating. Apply the mixed coating evenly to the surface of the soaked linen using a spraying process and let it stand for 5 hours. Then, dry the linen coated with the coating in an oven at 40°C to obtain superhydrophobic linen.
[0069] Water droplet contact angle measurements were performed on the superhydrophobic linen fabric. The results showed a water droplet contact angle greater than 150° and a water roll-off angle less than 10°. Using the superhydrophobic linen fabric as a filter, and selecting chloroform, n-hexane, and n-decane as oil phases, oil-water separation tests were conducted. The oil-water separation efficiency was consistently higher than 98%, indicating excellent oil-water separation performance. Durability and stability tests, including load-bearing abrasion, acid and alkali solution immersion, and ultraviolet radiation, were performed on the superhydrophobic linen fabric, which still exhibited excellent superhydrophobicity. Field scanning electron microscopy (SEM) observation of the microstructure of the original cotton fabric and the superhydrophobic linen fabric revealed no significant difference between the fibers, indicating that the superhydrophobic coating prepared on the linen surface is very thin.
[0070] Example 4:
[0071] Mix 30 parts of diethylamine, 30 parts of butylene glycol diglycidyl ether, and 40 parts of tetrahydrofuran to obtain a mixed solution. Immerse the glass in the mixed solution. After 20 hours, remove the glass. Mix 25 parts of butyl acrylate, 10 parts of polydimethylsiloxane, 2 parts of azobisisobutyronitrile, 23 parts of dodecyl mercaptan, and 40 parts of tetrahydrofuran to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed substrate material using a spraying process and let it stand for 7 hours. Then, place the glass with the coating on the surface in an oven at 100°C and bake for 10 hours.
[0072] The water droplet contact angle of the superhydrophobic glass was measured. A schematic diagram of the water droplet contact angle measurement is shown below. Figure 2 As shown, θ is the angle being measured. A schematic diagram for measuring the rolling angle of a water droplet is shown below. Figure 3 As shown, α is the angle being measured. Tests revealed that the superhydrophobic glass exhibits a water droplet contact angle greater than 150° and a water droplet roll-off angle less than 10°.
[0073] The superhydrophobic glass was subjected to durability and stability tests, including load-bearing abrasion, immersion in acid and alkali solutions, and ultraviolet radiation. The superhydrophobic glass still exhibited excellent superhydrophobicity.
[0074] The microstructure of the original glass and the superhydrophobic glass was observed using field scanning electron microscopy, such as... Figure 5 (e) and Figure 5As shown in (f), there is no obvious difference between the original glass surface and the superhydrophobic glass surface, indicating that the superhydrophobic coating prepared on the glass surface is very thin.
[0075] Example 5:
[0076] Mix 20 parts triethylamine, 40 parts propylene glycol diglycidyl ether, and 40 parts anhydrous ethanol to obtain a mixed solution. Immerse book paper in the mixed solution. After 15 hours, remove the book paper. Mix 30 parts 2-ethylhexyl acrylate, 15 parts polydimethylsiloxane, 1 part azobisisobutyronitrile, 14 parts hexadecyl mercaptan, and 40 parts anhydrous ethanol to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed book paper using a spraying process and let it stand for 6 hours. Then, place the coated book paper in an oven at 200°C and bake for 7 hours to obtain superhydrophobic book paper.
[0077] Water droplet contact angle and water droplet roll-off angle were measured on the superhydrophobic book paper. The tests showed that the water droplet contact angle was greater than 150° and the water droplet roll-off angle was less than 10°. Using the superhydrophobic book paper as a filter, and selecting chloroform, n-hexane, and n-decane as oil phases, oil-water separation tests were conducted. The oil-water separation efficiency was higher than 98%, indicating that the superhydrophobic book paper has excellent oil-water separation performance. Durability and stability tests, including load abrasion, acid and alkali solution immersion, and ultraviolet radiation, were performed on the superhydrophobic book paper, and it still exhibited excellent superhydrophobicity. Field scanning electron microscopy (SEM) was used to observe the microstructure of the original book paper and the superhydrophobic book paper. There was no significant difference between the fibers of the original book paper and the superhydrophobic book paper, indicating that the superhydrophobic coating prepared on the surface of the book paper is very thin.
[0078] Example 6:
[0079] Mix 30 parts of diethylamine, 30 parts of butanediol diglycidyl ether, and 40 parts of N,N-dimethylformamide to obtain a mixed solution. Immerse polyethylene plastic in the mixed solution. After 20 hours, remove the polyethylene plastic. Mix 25 parts of dodecyl acrylate, 32 parts of polydimethylsiloxane, 2 parts of azobisisobutyronitrile, 1 part of decanethiol, and 40 parts of N,N-dimethylformamide to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed polyethylene plastic using a spraying process and let it stand for 7 hours. Then, place the polyethylene plastic with the coating on its surface in an oven at 100°C and bake for 10 hours to obtain superhydrophobic polyethylene plastic.
[0080] The water droplet contact angle and water droplet roll-off angle of the superhydrophobic plastic were measured. The tests showed that the water droplet contact angle of the superhydrophobic plastic was greater than 150° and less than 10°. Durability and stability tests, including those involving heavy-duty wear, immersion in acid and alkali solutions, and ultraviolet radiation, were conducted on the superhydrophobic plastic, which still exhibited excellent superhydrophobic properties.
[0081] Example 7:
[0082] Mix 20 parts triethylamine, 40 parts hexanediol diglycidyl ether, and 40 parts tetrahydrofuran to obtain a mixed solution. Immerse acrylic fabric in the mixed solution. After 15 hours, remove the acrylic fabric. Mix 30 parts benzyl acrylate, 25 parts polydimethylsiloxane, 20 parts azobisisobutyronitrile, 24 parts cyclohexanethiol, and 1 part tetrahydrofuran to obtain a mixed coating. Apply the mixed coating evenly to the surface of the immersed acrylic fabric using a spraying process and let it stand for 6 hours. Then, place the coated acrylic fabric in an oven at 200°C and bake for 7 hours to obtain a superhydrophobic acrylic fabric.
[0083] Water droplet contact angle and water droplet roll-off angle were measured on the superhydrophobic acrylic fabric. The tests showed that the water droplet contact angle of the superhydrophobic acrylic fabric was greater than 150°, and the water droplet roll-off angle was less than 10°. Using the superhydrophobic acrylic fabric as a filter, and selecting chloroform, n-hexane, and n-decane as representative oil phases, oil-water separation tests were conducted. The oil-water separation efficiency was higher than 98%, indicating that the superhydrophobic acrylic fabric has excellent oil-water separation performance. Durability and stability tests, including load abrasion, acid and alkali solution immersion, and ultraviolet radiation, were performed on the superhydrophobic acrylic fabric, and it still exhibited excellent superhydrophobicity. Field scanning electron microscopy (SEM) was used to observe the microstructure of the original acrylic fabric and the superhydrophobic acrylic fabric. There was no significant difference between the fibers of the original acrylic fabric and the superhydrophobic acrylic fabric, indicating that the superhydrophobic coating prepared on the surface of the acrylic fabric is very thin.
[0084] Example 8:
[0085] This embodiment is essentially the same as Embodiment 4, except that butyl acrylate is replaced with phenyl acrylate, dodecyl mercaptan is replaced with octadecyl mercaptan, glass is replaced with wood, and tetrahydrofuran is replaced with ethyl acetate. The water droplet contact angle and water droplet roll-off angle of the superhydrophobic wood were measured. The tests showed that the water droplet contact angle of this superhydrophobic wood was greater than 150°, and the water droplet roll-off angle was less than 10°. Durability and stability tests, including load abrasion, acid and alkali solution immersion, and ultraviolet radiation, were conducted on the superhydrophobic wood, and it still exhibited excellent superhydrophobicity.
[0086] Example 9:
[0087] This embodiment is basically the same as Embodiment 4, except that butyl acrylate is replaced with cyclohexyl acrylate, dodecyl mercaptan is replaced with hexadecyl mercaptan, propylene glycol diglycidyl ether is replaced with neopentyl glycol diglycidyl ether, and glass is replaced with polyvinyl chloride plastic. The water droplet contact angle and water droplet roll-off angle of the superhydrophobic plastic were measured. The test results showed that the water droplet contact angle of the superhydrophobic plastic was greater than 150°, and the water droplet roll-off angle was less than 10°. Durability and stability tests, including load-bearing abrasion, acid and alkali solution immersion, and ultraviolet radiation, were conducted on the superhydrophobic plastic, and it still exhibited excellent superhydrophobicity.
[0088] The embodiments described above are merely illustrative of several implementations of the present invention, and are not limited to these embodiments. Other changes and modifications made by those skilled in the art without departing from the concept of the present invention should all fall within the scope of protection of the present invention.
Claims
1. An ultrathin superhydrophobic coating based on fluorine-free organic small molecules, characterized in that, By weight parts The mixed solution comprises 20 to 40 parts of an amine compound, 20 to 40 parts of an epoxy compound, and 20 to 40 parts of a solvent; The mixed coating comprises 1 to 30 parts of an olefin compound, 1 to 25 parts of polydimethylsiloxane, 1 to 25 parts of an initiator, 1 to 40 parts of a mercapto compound, and 1 to 40 parts of a solvent; After immersing the substrate in the mixed solution, the mixed coating is applied to the surface of the immersed substrate material and then dried to obtain an ultrathin superhydrophobic coating on the substrate. In the mixed solution, the amine compounds include one or more of the following: ethylamine, propylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, aniline, diphenylamine, pyridine, diethylenetriamine, and triethylenetetramine; Epoxy compounds include one or more of the following: ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol diglycidyl ether, cyclohexanediol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, and diglycidyl terephthalate. Alkenes include one or more of the following: methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, dodecyl acrylate, cyclohexyl acrylate, benzyl acrylate, and phenyl acrylate. Thiol compounds include one or more of the following: ethanethiol, propylene dithiol, butanethiol, pentathiol, hexanethiol, cyclopentanethiol, cyclohexanethiol, octylthiol, decanethiol, dodecylthiol, hexadecylthiol, and octadecylthiol.
2. The ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to claim 1, characterized in that, In mixed coatings: Initiators include azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, potassium persulfate, di-tert-butyl peroxide, cumene hydroperoxide, triphenylphosphine oxide, isopropylthioxanthone, alpha-hydroxyisobutyrophenone, or photoinitiator 907.
3. The ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to claim 1, characterized in that, The solvent for the mixed solution or mixed coating is selected from one of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethyl sulfoxide, anhydrous ethanol, methanol, diethyl ether, acetone, ethyl acetate, butyl acetate, cyclohexane, and toluene.
4. The ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to claim 1, characterized in that, The substrate includes one or more of the following: paper, natural fibers, synthetic fibers, plastics, glass, ceramics, wood, wood-plastic composites, and concrete.
5. The ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to claim 1, characterized in that, The mixed coating is applied to the surface of the substrate material after immersion using processes such as soaking, spraying, spin coating, printing, or UV curing.
6. A method for preparing an ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to any one of claims 1 to 5, characterized in that, The specific steps are as follows: S1 involves immersing the substrate in a mixed solution with continuous stirring during the immersion process to obtain a pretreated substrate. The mixed solution is obtained by mixing amine compounds, epoxy compounds, and solvents. S2 coats a pretreated substrate with a mixed coating, allows it to stand, and dries to obtain an ultrathin superhydrophobic coating.
7. The method for preparing an ultrathin superhydrophobic coating based on fluorine-free organic small molecules according to claim 6, characterized in that, In S1, the substrate is immersed in the mixed solution for 1 h to 24 h; in S2, the pretreated substrate is covered with the mixed coating, left to stand for 1 h to 7 h, and then dried at a temperature of 40℃ to 200℃.
8. A product with superhydrophobic properties, characterized in that, It includes a substrate and an ultrathin superhydrophobic coating covering the substrate, wherein the ultrathin superhydrophobic coating is the ultrathin superhydrophobic coating according to any one of claims 1 to 5 or the ultrathin superhydrophobic coating prepared by the preparation method according to claim 6.
9. A product with superhydrophobic function according to claim 8, characterized in that, The substrate includes one or more of the following: paper, natural fibers, synthetic fibers, plastics, glass, ceramics, wood, wood-plastic composites, and concrete.