An aqueous super-hydrophobic coating, its preparation method and use

Abstract

The application discloses a kind of water-based super-hydrophobic coating and its preparation method and application, the preparation method includes steps: (1) the oil phase material with photo-crosslinking curing characteristics is mixed uniformly with photo-initiator, and oil phase is obtained;(2) nanoparticle and surfactant are added to aqueous solution and mixed uniformly, and water phase is obtained;(3) oil phase is mixed uniformly with water phase and ultrasonic dispersion, and oil-in-water Pickering emulsion is obtained;(4) oil-in-water Pickering emulsion is treated with ultraviolet lamp irradiation, and oil drop in emulsion is photo-cured to form stable water-based super-hydrophobic coating.The preparation method provided by the application is simple, and the water-based super-hydrophobic coating prepared has the advantages of green environmental protection, good stability and the like.

Description

Technical Field

[0001] This invention relates to the field of superhydrophobic materials technology, specifically to a water-based superhydrophobic coating, its preparation method, and its application. Background Technology

[0002] Superhydrophobic surfaces are special super-wetting surfaces with a water contact angle greater than 150° and a roll-off angle less than 10°. This unique superwetting property is achieved through the combined effect of low surface energy and high roughness. Due to their excellent water-repellent and self-cleaning properties, superhydrophobic surfaces have broad application prospects in fields such as oil-water separation, anti-icing, self-cleaning, corrosion resistance, and drag reduction.

[0003] Existing superhydrophobic coatings mostly use volatile organic solvents as solvents, and volatile organic compounds (VOCs) pose significant environmental and health hazards, contradicting the principles of green chemistry. If water is used instead of organic solvents, the poor dispersibility of low surface energy polymers in water leads to agglomeration and sedimentation in water-based superhydrophobic coatings, resulting in uneven superhydrophobic coatings. Therefore, there is an urgent need to research a stable water-based superhydrophobic coating. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a water-based superhydrophobic coating, its preparation method, and its application. The preparation method is simple, and the prepared water-based superhydrophobic coating has advantages such as being environmentally friendly and having good stability.

[0005] The technical solution adopted in this invention is as follows:

[0006] One objective of this invention is to provide a method for preparing a water-based superhydrophobic coating, comprising the following steps:

[0007] (1) Mix the oil phase substance with photocrosslinking curing properties with a photoinitiator evenly to obtain an oil phase;

[0008] (2) Add nanoparticles and surfactants to an aqueous solution and mix thoroughly to obtain an aqueous phase;

[0009] (3) The oil phase and the water phase are mixed evenly and ultrasonically dispersed to obtain an oil-in-water Pickering emulsion;

[0010] (4) The oil-in-water Pickering emulsion was treated with ultraviolet light and the oil droplets in the emulsion were photocured to form a stable water-based superhydrophobic coating.

[0011] Further, in step (1), the oil phase substance is at least one of polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, ethyl 2-dimethacrylate, octadecenoic acid, and trimethylpropane triacrylate.

[0012] The photoinitiator is 2-hydroxy-2-methylphenylacetone, and the concentration of the photoinitiator in the oil phase is 0.01-15%.

[0013] Furthermore, in step (2), the nanoparticles are at least one of silica nanoparticles, carbon nanotubes, polysaccharides, titanium dioxide, and starch.

[0014] Further, in step (2), the surfactant is at least one of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, FS-48, FS-61, polyvinyl alcohol, and alkylphenol polyoxyethylene ether.

[0015] Furthermore, the concentration of nanoparticles in the aqueous phase formed in step (2) is 0-10 wt%, preferably 0-5 wt%.

[0016] The concentration of surfactant in the aqueous phase formed in step (2) is 0.01-10 wt%, preferably 0.01-5 wt%.

[0017] Furthermore, in step (3), the mass ratio of the oil phase to the water phase is 1:1 to 40.

[0018] Furthermore, the UV lamp irradiation time in step (4) is 0 to 60 minutes.

[0019] Another object of the present invention is to provide a water-based superhydrophobic coating.

[0020] Another objective of this invention is to provide an application of a water-based superhydrophobic coating, wherein the prepared water-based superhydrophobic coating is coated onto a substrate and cured to form a superhydrophobic coating, and the rough structure of the surface of the superhydrophobic coating is microsphere-like.

[0021] Furthermore, after the water-based superhydrophobic coating is applied to the substrate, it is first irradiated with a UV lamp for 0–60 min, and then cured at 25–100℃ for 5 min–24 h.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) This invention obtains a stable oil-in-water Pickering emulsion by mixing and ultrasonically dispersing the hydrophobic polymer oil phase with the water phase. After photocuring the emulsion, a stable waterborne superhydrophobic material with micro-nano structure can be obtained. The coating emulsion remains stable after standing for 9 months, which has strong practicality.

[0024] (2) This invention does not use organic solvents but uses water as a solvent, which avoids the pollution caused by the volatilization of organic solvents. Moreover, the preparation method is simple and environmentally friendly. It can build superhydrophobic surfaces on a variety of substrates and has broad application prospects. Attached Figure Description

[0025] To clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A photograph of the aqueous superhydrophobic coating emulsion prepared in Example 1 of the present invention stored in a container;

[0027] Figure 2 This is a schematic diagram illustrating the preparation of the waterborne superhydrophobic coating emulsion according to the present invention;

[0028] Figure 3 This is a SEM image of the surface of the superhydrophobic film prepared in Example 3 of the present invention;

[0029] Figure 4 This is a SEM image of the surface of the superhydrophobic film prepared in Example 4 of the present invention. Detailed Implementation

[0030] This invention provides a water-based superhydrophobic coating, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] The present invention will now be described in detail with reference to the accompanying drawings.

[0032] Example 1

[0033] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0034] (1) 1g of vinyl-terminated polydimethylsiloxane and 0.1g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain an oil phase;

[0035] (2) Mix 20g of deionized water, 0.102g of silica nanoparticles (particle size 15nm) and 0.02g of sodium dodecylbenzenesulfonate and ultrasonically disperse for 10min to obtain an aqueous phase;

[0036] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0037] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0038] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0039] The water contact angle of the membrane before and after coating with superhydrophobic coating was tested. Before coating with superhydrophobic coating, the water contact angle of the membrane was 33.2°, while the water contact angle of the superhydrophobic membrane after coating with superhydrophobic coating was 151.5°, indicating that the hydrophilic surface was successfully modified into a superhydrophobic surface by the coating.

[0040] Following the steps described above, six batches of waterborne superhydrophobic coating emulsions were prepared and stored in sealed containers, such as... Figure 1 As shown, where Figure 1 Image a shows a photograph of the waterborne superhydrophobic coating emulsion immediately after preparation, while image b shows a photograph of the waterborne superhydrophobic coating emulsion after 9 months of storage. From Figure 1 As can be seen, the emulsion remained stable after being left to stand for 9 months.

[0041] Additionally, refer to Figure 2 This paper explains the superhydrophobicity and stability of the aqueous superhydrophobic coating emulsion prepared in this embodiment. When the oil phase and water phase are ultrasonically dispersed, an oil-in-water Pickering emulsion is formed. The oil phase droplets are uniformly dispersed in the water, while nanoparticles coat the oil phase droplets. After ultraviolet irradiation, in-situ photocuring occurs, forming a microsphere structure that remains unchanged. The nanoparticles on the surface of the oil phase droplets are distributed at the oil-water interface, enabling the emulsion to remain stable. Furthermore, the oil phase in the photocured microsphere structure provides micron-sized structures, while the nanoparticles on its surface provide nano-structures, thus forming a micro-micro-nano composite structure to improve roughness and achieve superhydrophobicity.

[0042] Example 2

[0043] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0044] (1) 1g of vinyl-terminated polydimethylsiloxane, 0.1g of octadecenoic acid and 0.11g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0045] (2) Mix 20g of deionized water, 0.102g of silica nanoparticles (particle size 15nm) and 0.02g of hexadecyltrimethylammonium bromide and ultrasonically disperse for 10min to obtain an aqueous phase;

[0046] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0047] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0048] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0049] The water contact angle of the superhydrophobic film in this embodiment was tested, and the water contact angle was found to be 152.3°.

[0050] Example 3

[0051] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0052] (1) 1g of vinyl-terminated polydimethylsiloxane and 0.1g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain an oil phase;

[0053] (2) Mix 20g of deionized water, 0.102g of silica nanoparticles (15nm) and 0.02g of hexadecyltrimethylammonium bromide and ultrasonically disperse for 10min to obtain an aqueous phase;

[0054] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0055] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0056] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0057] The surface of the superhydrophobic film prepared in this embodiment was examined by electron microscopy, such as... Figure 3 As shown in (a) and (b), it can be seen from the figures that the rough structure on the surface of the superhydrophobic film is microsphere-shaped, and the surface of the microsphere-shaped structure has nanoparticles. The microsphere-shaped structure is a siloxane polymer, and the nanoparticles on the surface of the microsphere-shaped structure are silicon dioxide nanoparticles.

[0058] In addition, the water contact angle of the superhydrophobic film in this embodiment was tested, such as... Figure 3 As shown in (c), the water contact angle obtained by the test was 161.5°.

[0059] Example 4

[0060] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0061] (1) 1g of vinyl-terminated polydimethylsiloxane, 0.1g of octadecenoic acid and 0.1g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0062] (2) Mix 20g of deionized water, 0.102g of silica nanoparticles (15nm) and 0.2g of FS-61 and ultrasonically disperse for 10min to obtain an aqueous phase;

[0063] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0064] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0065] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0066] The surface of the superhydrophobic film prepared in this embodiment was examined by electron microscopy, such as... Figure 4 As shown in (a) and (b), it can be seen from the figures that the rough structure on the surface of the superhydrophobic film is microsphere-shaped, and the surface of the microsphere-shaped structure has nanoparticles. The microsphere-shaped structure is a siloxane polymer, and the nanoparticles on the surface of the microsphere-shaped structure are silicon dioxide nanoparticles.

[0067] In addition, the water contact angle of the superhydrophobic film in this embodiment was tested, such as... Figure 4 As shown in (c), the water contact angle obtained by the test was 172.1°.

[0068] Example 5

[0069] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0070] (1) 1g of vinyl-terminated polydimethylsiloxane, 0.1g of octadecenoic acid and 0.01g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0071] (2) Mix 20g of deionized water, 1.05g of silica nanoparticles (50nm) and 0.2g of cetyltrimethylammonium bromide and ultrasonically disperse for 10min to obtain an aqueous phase;

[0072] (3) Mix the oil phase and the water phase at a ratio of 1:20 and ultrasonically disperse for 15 min to obtain an oil-in-water Pickering emulsion;

[0073] (4) Irradiate the emulsion under ultraviolet light at room temperature for 30 minutes to obtain a water-based superhydrophobic coating emulsion;

[0074] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 30 minutes to make it completely crosslinked. Then the obtained membrane is placed in a 30°C oven for 10 hours to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0075] The water contact angle of the superhydrophobic film in this embodiment was tested and found to be 171.9°.

[0076] Example 6

[0077] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0078] (1) Disperse 0.5g of polydimethylsiloxane, 0.5g of vinyl-terminated polydimethylsiloxane, 0.1g of octadecenoic acid and 0.06g of 2-hydroxy-2-methylphenylacetone by ultrasonication for 10min to obtain the oil phase;

[0079] (2) Mix 20g of deionized water, 1.11g of silica nanoparticles (15nm), and 1.11g of FS-61 and ultrasonically disperse for 10min to obtain an aqueous phase;

[0080] (3) Mix the oil phase and the water phase at a ratio of 1:40 and ultrasonically disperse for 5 min to obtain an oil-in-water Pickering emulsion;

[0081] (4) Irradiate the emulsion under ultraviolet light at room temperature for 60 minutes to obtain a water-based superhydrophobic coating emulsion;

[0082] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 10 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0083] The water contact angle of the superhydrophobic film in this embodiment was tested, and the water contact angle was found to be 171.5°.

[0084] Example 7

[0085] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0086] (1) 1g of ethyl 2-dimethacrylate, 0.1g of octadecenoic acid, and 0.06g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0087] (2) Mix 20g of deionized water, 2.5g of silica nanoparticles (15nm) and 3.5g of alkylphenol polyoxyethylene ether and ultrasonically disperse for 10min to obtain an aqueous phase;

[0088] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0089] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0090] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0091] The water contact angle of the superhydrophobic film in this embodiment was tested, and the water contact angle was found to be 159.3°.

[0092] Example 8

[0093] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0094] (1) 1g of vinyl-terminated polydimethylsiloxane, 1g of ethyl 2-dimethacrylate, 0.1g of octadecenoic acid and 0.1g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0095] (2) Mix 20g of deionized water and 0.2g of FS-48 and ultrasonically disperse for 10min to obtain an aqueous phase;

[0096] (3) Mix the oil phase and the water phase in a 1:1 ratio and ultrasonically disperse for 15 min to obtain an oil-in-water Pickering emulsion;

[0097] (4) Irradiate the emulsion under ultraviolet light for 5 minutes at room temperature to obtain a water-based superhydrophobic coating emulsion;

[0098] (5) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the membrane is irradiated with ultraviolet light for 5 minutes to make it fully crosslinked. Then the obtained membrane is placed in an 80℃ oven for 10 minutes to obtain a microfiltration membrane with a superhydrophobic coating, which is a superhydrophobic membrane.

[0099] The water contact angle of the superhydrophobic film in this embodiment was tested, and the water contact angle was found to be 155.7°.

[0100] Example 9

[0101] This embodiment provides a water-based superhydrophobic coating and a superhydrophobic coating layer, the steps of which are as follows:

[0102] (1) 1g of vinyl-terminated polydimethylsiloxane, 1g of ethyl 2-dimethacrylate, 0.1g of octadecenoic acid and 0.1g of 2-hydroxy-2-methylphenylacetone were ultrasonically dispersed for 10min to obtain the oil phase;

[0103] (2) Mix 20g of deionized water, 0.051g of silica nanoparticles (15nm), 0.051g of carbon nanotubes and 0.2g of polyvinyl alcohol and ultrasonically disperse for 10min to obtain an aqueous phase;

[0104] (3) Mix the oil phase and the water phase at a ratio of 1:13 and ultrasonically disperse for 10 min to obtain an oil-in-water Pickering emulsion;

[0105] (4) The water-based superhydrophobic coating emulsion is uniformly coated on the microfiltration membrane, and then the resulting membrane is placed in a 50°C oven for 20 hours to obtain a microfiltration membrane with a superhydrophobic coating, i.e., a superhydrophobic membrane.

[0106] The water contact angle of the superhydrophobic film in this embodiment was tested, and the water contact angle was found to be 151.1°.

[0107] It should be noted that any parts not mentioned in this invention can be achieved by using or referencing existing technologies.

[0108] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing a water-based superhydrophobic coating, characterized in that, Including the following steps: (1) Mix the oil phase substance with photocrosslinking curing properties with the photoinitiator evenly to obtain the oil phase; (2) Add nanoparticles and surfactants to an aqueous solution and mix thoroughly to obtain an aqueous phase; (3) The oil phase and the water phase are mixed evenly and ultrasonically dispersed to obtain an oil-in-water Pickering emulsion, in which the oil phase droplets are evenly dispersed in the water and the nanoparticles are coated around the oil phase droplets. (4) The oil-in-water Pickering emulsion was treated with ultraviolet light and the oil droplets in the emulsion were photocured to form a stable waterborne superhydrophobic coating. The water-based superhydrophobic coating has a microsphere structure and is coated with nanoparticles on its surface.

2. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, In step (1), the oil phase substance is at least one of terminal vinyl polydimethylsiloxane, ethyl 2-dimethacrylate, octadecenoic acid, trimethylpropane triacrylate, or a combination of polydimethylsiloxane and terminal vinyl polydimethylsiloxane. The photoinitiator is 2-hydroxy-2-methylphenylacetone, and the concentration of the photoinitiator in the oil phase is 0.01~15wt%.

3. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, In step (2), the nanoparticles are at least one of silica nanoparticles, carbon nanotubes, polysaccharides, and titanium dioxide.

4. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, The surfactant in step (2) is at least one of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, FS-48, FS-61, polyvinyl alcohol, and alkylphenol polyoxyethylene ether.

5. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, The concentration of nanoparticles in the aqueous phase formed in step (2) is 0.5~10wt%; The concentration of surfactant in the aqueous phase formed in step (2) is 0.01~10wt%.

6. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, In step (3), the mass ratio of the oil phase to the water phase is 1:1 to 40.

7. The method for preparing a waterborne superhydrophobic coating according to claim 1, characterized in that, The UV lamp irradiation time in step (4) is 5~60 minutes.

8. A water-based superhydrophobic coating, characterized in that, It is prepared using the preparation method described in any one of claims 1 to 7.

9. An application of a water-based superhydrophobic coating, characterized in that, The water-based superhydrophobic coating of claim 8 is applied to a substrate and cured to form a superhydrophobic coating, wherein the rough structure of the surface of the superhydrophobic coating is microsphere-shaped.

10. The application of the waterborne superhydrophobic coating according to claim 9, characterized in that, After the water-based superhydrophobic coating is applied to the substrate, it is first irradiated with a UV lamp for 0-60 minutes, and then cured at 25-100℃ for 5 minutes to 24 hours.

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