Method for producing a superhydrophobic coating and superhydrophobic coating

Abstract

The application provides a preparation method of a super-hydrophobic coating and the super-hydrophobic coating. The preparation method comprises the following steps: mixing a main body material with a solvent to prepare a mixed solution, wherein the main body material comprises nano-aluminum hydroxide and micro-aluminum hydroxide; mixing the mixed solution with hexadecyl trimethoxysilane, ultrapure water, acetic acid and a silane coupling agent to prepare a spraying solution; and spraying the spraying solution on a substrate surface to prepare the super-hydrophobic coating. By using appropriate components to prepare the spraying solution and spraying the spraying solution on the substrate surface by using a spraying method, the super-hydrophobic coating with a high static contact angle and a low rolling angle is prepared, and the super-hydrophobic coating has good durability while having the super-hydrophobic property. Meanwhile, the preparation process is simple and convenient.

Description

Technical Field

[0001] This application relates to the field of drag reduction technology, and in particular to a method for preparing a superhydrophobic coating and the superhydrophobic coating itself. Background Technology

[0002] Superhydrophobic surfaces play a significant role in antifouling and waterproofing, self-cleaning, corrosion resistance, and drag reduction, leading to their increasingly widespread application. While various methods exist for obtaining superhydrophobic surfaces, most require stringent preparation processes and conditions, resulting in complex fabrication procedures. Furthermore, superhydrophobic surfaces often suffer from poor durability.

[0003] Therefore, there is an urgent need for a simple and quick method to prepare superhydrophobic coatings with good durability. Summary of the Invention

[0004] Based on this, this application provides a method for preparing a superhydrophobic coating, so as to simply and quickly prepare a superhydrophobic coating with good durability.

[0005] The first aspect of this application provides a method for preparing a superhydrophobic coating, comprising the following steps:

[0006] A mixture is prepared by mixing a main material with a solvent; the main material includes nano-aluminum hydroxide and micron-aluminum hydroxide.

[0007] The mixture is combined with hexadecyltrimethoxysilane, ultrapure water, acetic acid and silane coupling agent to prepare a spraying solution;

[0008] The superhydrophobic coating is prepared by spraying the coating liquid onto the substrate surface.

[0009] In some embodiments, the mass ratio of the micron-sized aluminum hydroxide to the nano-sized aluminum hydroxide in the main material is (1-6):4.

[0010] In some embodiments, the volume-to-mass ratio of the hexadecyltrimethoxysilane to the host material is ≥1 ml:2 g, optionally (1-5) ml:2 g, and further optionally (1-4) ml:2 g.

[0011] In some embodiments, the volume-to-mass ratio of the ultrapure water to the main material is (1.9-2.1) ml:2 g.

[0012] In some embodiments, the volume-to-mass ratio of acetic acid to the host material is (0.95-1.05) ml: 2 g.

[0013] In some embodiments, the silane coupling agent includes γ-glycidoxypropyltrimethoxysilane;

[0014] Optionally, the volume-to-mass ratio of the silane coupling agent to the host material is (0.5-4) ml: 2 g.

[0015] In some embodiments, the step of mixing the mixture with hexadecyltrimethoxysilane, ultrapure water, acetic acid, and a silane coupling agent includes:

[0016] The mixture is stirred with the hexadecyltrimethoxysilane, the ultrapure water and the acetic acid, and then a silane coupling agent is added and stirring is continued.

[0017] In some embodiments, the spraying pressure is 0.3 MPa-0.5 MPa; and / or

[0018] The spraying is performed using a spray gun, with the vertical distance between the spray gun nozzle and the substrate surface being 25cm-30cm; and / or

[0019] The substrate is made of aluminum alloy.

[0020] In some embodiments, the method further includes a step of drying the substrate surface after spraying;

[0021] Optionally, the drying process is carried out at a temperature of 75℃-85℃ for 10h-14h.

[0022] The second aspect of this application provides a superhydrophobic coating, which is prepared using the preparation method of the first aspect of this application;

[0023] Optionally, the static contact angle of the superhydrophobic coating is ≥150°;

[0024] Optionally, the roll-off angle of the superhydrophobic coating is ≤10°.

[0025] The above-described method for preparing a superhydrophobic coating involves preparing a spraying liquid using suitable component ratios, and then spraying the spraying liquid onto the substrate surface using a spraying method. This results in a superhydrophobic coating with a high static contact angle and a low roll-off angle, exhibiting both superhydrophobic properties and good durability. Furthermore, the preparation process is simple and convenient. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1The results of static contact angle and ultrasonic 1-hour contact angle tests of the superhydrophobic coatings in Examples 1-5 and Comparative Example 1 are shown.

[0028] Figure 2 The changes in contact angle and roll-off angle of the superhydrophobic coating in Example 1 over time during 1 hour of ultrasonication;

[0029] Figure 3 This refers to the minimum roll-off angle of the superhydrophobic coating in Example 1;

[0030] Figure 4 This represents the maximum contact angle of the superhydrophobic coating in Example 1;

[0031] Figure 5 The image shows the SEM image of the superhydrophobic coating in Example 1 at a magnification of 1K.

[0032] Figure 6 The image shows the SEM image of the superhydrophobic coating in Example 1 at a magnification of 2K.

[0033] Figure 7 SEM image of the superhydrophobic coating in Example 1 at a magnification of 5K;

[0034] Figure 8 The contact angle and roll-off angle test results are for the superhydrophobic coatings in Examples 1, 6-9 and Comparative Example 2;

[0035] Figure 9 The results are the contact angle and roll-off angle test results of the superhydrophobic coatings in Examples 1, 10-12 and Comparative Examples 3-4. Detailed Implementation

[0036] To facilitate understanding of the present invention, a more complete description of this application will be provided below with reference to relevant embodiments. Preferred embodiments of the present application are given below. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of this application will be achieved.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0038] As used herein, the terms "and / or," "or / and," and "and / or" encompass any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that, in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR."

[0039] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0040] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0041] This document only specifically discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0042] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows temperature fluctuations within the precision range controlled by the instrument, such as ±5°C, ±4°C, ±3°C, ±2°C, or ±1°C.

[0043] In this application, unless otherwise specified, the terms "size," "particle size," and "diameter" generally refer to average values. In this application, "particle size" and "particle diameter" have the same definition, both representing the average particle size of spheres or spheroids.

[0044] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0045] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0046] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0047] In the description of the application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0049] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, but sequentially is preferred.

[0050] In related technologies, there are various methods to obtain superhydrophobic surfaces, but most methods have high requirements for preparation processes and conditions, and the preparation process is relatively complex; in addition, superhydrophobic surfaces also have the problem of poor durability.

[0051] Based on the above problems, this application prepares a spraying liquid by using a suitable formula and prepares a superhydrophobic coating by combining it with a spraying method. The superhydrophobic coating has good durability while possessing superhydrophobic properties.

[0052] The first aspect of this application provides a method for preparing a superhydrophobic coating, comprising the following steps: mixing a host material with a solvent to prepare a mixture; mixing the mixture with hexadecyltrimethoxysilane, ultrapure water, acetic acid and a silane coupling agent to prepare a spraying liquid; and spraying the spraying liquid onto a substrate surface to prepare a superhydrophobic coating; wherein the host material includes nano-aluminum hydroxide and micron-aluminum hydroxide.

[0053] The method for preparing the superhydrophobic coating provided in this application utilizes a mixture of micron-sized and nano-sized aluminum hydroxide doping to improve the strength and stability of the coating. Hexadecyltrimethoxysilane, being hydrophobic, can be used as a superhydrophobic modifier to enhance the hydrophobicity of the coating. After hydrolysis, hexadecyltrimethoxysilane dehydrates and bonds with aluminum hydroxide particles to form superhydrophobic particles. The silane coupling agent, after hydrolysis and dehydration, acts as a binder. Therefore, the superhydrophobic coating prepared by the above method exhibits good durability and stability.

[0054] Nano-sized aluminum hydroxide enhances bonding strength and regulates the surface roughness of superhydrophobic surfaces; micron-sized aluminum hydroxide can form a secondary structure with the polymerized lamellar spherical structure of hexadecyltrimethoxysilane, effectively ensuring superhydrophobicity. Both nano-sized and micron-sized aluminum hydroxides readily bond with hydrolyzed hexadecyltrimethoxysilane, achieving a modification effect. Therefore, using both nano-sized and micron-sized aluminum hydroxide simultaneously in the preparation of superhydrophobic coatings is beneficial for improving the coating's strength and stability. Aluminum hydroxide is a good modifying substrate particle, readily bonding with modifiers to form superhydrophobic particles.

[0055] Hexadecyltrimethoxysilane, with its long carbon chain and terminal methyl group, as well as its low surface energy, provides hydrophobicity when used as a modifier, facilitating the achievement of superhydrophobicity. By adding hexadecyltrimethoxysilane, it can serve as a superhydrophobic modifier, improving the hydrophobicity of the coating.

[0056] By adding acetic acid, the pH of the solution can be adjusted to achieve the optimal range for the hydrolysis of hexadecyltrimethoxysilane.

[0057] By adding ultrapure water, a hydrolytic environment can be provided.

[0058] Adding a silane coupling agent can improve adhesion and enhance coating strength.

[0059] Understandably, the method for preparing the superhydrophobic coating provided in this application involves preparing a spraying liquid using suitable component formulations, and then spraying the spraying liquid onto the substrate surface using a spraying method to obtain a superhydrophobic coating with a high static contact angle and a low roll-off angle. Furthermore, this superhydrophobic coating possesses both superhydrophobic properties and good durability. Moreover, the preparation process is simple and convenient.

[0060] Furthermore, the method for preparing the superhydrophobic coating provided in this application innovatively prepares a two-dimensional structure of lamellar spheres and particles, which effectively ensures the superhydrophobicity.

[0061] In some embodiments, the solvent is anhydrous ethanol. As an example, the volume-to-mass ratio of anhydrous ethanol to the bulk material is 20 ml: 2 g.

[0062] In some embodiments, the mass ratio of micron-sized aluminum hydroxide to nano-sized aluminum hydroxide in the main material is (1-6):4. As an example, the mass ratio of micron-sized aluminum hydroxide to nano-sized aluminum hydroxide can be, but is not limited to, 1:4, 1.5:4, 2:4, 2.5:4, 3:4, 3.5:4, 4:4, 4.5:4, 5:4, 5.5:4, 6:4, or any range between two of the above ratios.

[0063] Excessive nano-aluminum hydroxide and insufficient micron-aluminum hydroxide will mask the secondary structure and worsen the superhydrophobicity of the coating. Insufficient nano-aluminum hydroxide and excessive micron-aluminum hydroxide will result in a rougher coating, which is not conducive to obtaining stable superhydrophobicity and will also reduce the coating strength. Excessive micron-aluminum hydroxide will result in a rougher coating and a lower coating strength compared to when there are more nano-particles. Insufficient micron-aluminum hydroxide will affect the secondary structure and thus have a negative impact on the superhydrophobicity.

[0064] As one possible implementation, the volume-to-mass ratio of hexadecyltrimethoxysilane to the host material is ≥1 ml:2 g. Optionally, the volume-to-mass ratio of hexadecyltrimethoxysilane to the host material is (1-5) ml:2 g. For example, it can be, but is not specifically limited to, 1 ml:2 g, 1.5 ml:2 g, 2 ml:2 g, 2.5 ml:2 g, 3 ml:2 g, 3.5 ml:2 g, 4 ml:2 g, 4.5 ml:2 g, 5 ml:2 g, or any range between two of the above ratios. Further optionally, the volume-to-mass ratio of hexadecyltrimethoxysilane to the host material is (1-4) ml:2 g.

[0065] If too little hexadecyltrimethoxysilane is used, the coating cannot achieve superhydrophobicity; if too much hexadecyltrimethoxysilane is used, its hydrolysis efficiency may decrease and the cost may increase.

[0066] In some embodiments, the volume-to-mass ratio of ultrapure water to the main material is (1.9-2.1) ml:2 g. As an example, the volume-to-mass ratio of ultrapure water to the main material can be, but is not limited to, 1.9 ml:2 g, 1.95 ml:2 g, 2 ml:2 g, 2.05 ml:2 g, 2.1 ml:2 g, or any range between the above two ratios. Insufficient ultrapure water hinders the hydrolysis of the silane coupling agent and hexadecyltrimethoxysilane; excessive ultrapure water results in an excessively low density of the spray solution.

[0067] As one possible implementation, the volume-to-mass ratio of acetic acid to the main material is (0.95-1.05) ml:2 g; for example, it can be, but is not limited to, 0.95 ml:2 g, 0.96 ml:2 g, 0.97 ml:2 g, 0.98 ml:2 g, 0.99 ml:2 g, 1 ml:2 g, 1.01 ml:2 g, 1.02 ml:2 g, 1.03 ml:2 g, 1.04 ml:2 g, 1.05 ml:2 g, or any range between two of the above ratios. When the amount of acetic acid is within the above range, the optimal pH value for the hydrolysis of hexadecyltrimethoxysilane can be achieved.

[0068] In some of these embodiments, the silane coupling agent includes γ-glycidoxypropyltrimethoxysilane.

[0069] In some optional embodiments, the volume-to-mass ratio of the silane coupling agent to the host material is (0.5-4) ml:2g. For example, it can be, but is not limited to, 0.5 ml:2g, 1 ml:2g, 1.5 ml:2g, 2 ml:2g, 2.5 ml:2g, 3 ml:2g, 3.5 ml:2g, 4 ml:2g, or any range between two of the above ratios. If the amount of silane coupling agent is too small, the coating adhesion will be poor; if the amount of silane coupling agent is too large, it will affect the superhydrophobicity.

[0070] In some embodiments, the step of mixing the mixture with hexadecyltrimethoxysilane, ultrapure water, acetic acid and silane coupling agent includes: mixing the mixture with hexadecyltrimethoxysilane, ultrapure water and acetic acid and stirring, then adding silane coupling agent and continuing to stir.

[0071] As an example, the mixture was mixed with hexadecyltrimethoxysilane, ultrapure water and acetic acid, and then stirred at 750 r / min at 25°C for 300 min using an electromagnetic stirrer. Then, a silane coupling agent was added and stirring was continued for 30 min to obtain the spraying liquid.

[0072] In some embodiments, the spraying pressure is 0.3 MPa-0.5 MPa; for example, it can be, but is not limited to, 0.3 MPa, 0.33 MPa, 0.35 MPa, 0.37 MPa, 0.4 MPa, 0.43 MPa, 0.45 MPa, 0.47 MPa, 0.5 MPa, or any range between two of the above pressures. If the spraying pressure is too high, the airflow velocity caused by the pressure is not conducive to molding; if the spraying pressure is too low, atomization is insufficient and the spraying effect is poor; when the spraying pressure is within the above range, atomization and molding effects are good.

[0073] As one possible implementation, spraying is performed using a spray gun, with the vertical distance between the spray gun nozzle and the substrate surface being 25cm-30cm; for example, it can be, but is not limited to, 25cm, 26cm, 27cm, 28cm, 29cm, 30cm, or any range between two of the above distances. When the vertical distance between the spray gun nozzle and the substrate surface is within the above range, the spraying is more uniform, the atomization is more complete, and the operation is convenient; if the distance is too large, the atomization is insufficient, wasting spray liquid; if the distance is too small, the spraying is uneven, and the surface is more affected by airflow.

[0074] In some implementations, the substrate material includes aluminum alloys.

[0075] As an example, when spraying, multiple layers are sprayed at intervals until the coating is evenly distributed and of moderate thickness.

[0076] In some embodiments, the process also includes a step of drying the substrate surface after spraying.

[0077] In some optional embodiments, the drying temperature is 75°C-85°C; for example, it can be, but is not limited to, 75°C, 78°C, 80°C, 83°C, 85°C, or any range between two of the above temperatures. The time is 10h-14h; for example, it can be, but is not limited to, 10h, 11h, 12h, 13h, 14h, or any range between two of the above times.

[0078] In some embodiments, before preparing the superhydrophobic coating, the aluminum alloy is polished with 1200-grit sandpaper and then washed alternately with anhydrous ethanol and deionized water as a base material for spraying.

[0079] The second aspect of this application provides a superhydrophobic coating prepared using the method described in the first aspect of this application. This superhydrophobic coating possesses both superhydrophobic properties and good durability.

[0080] In some implementations, the static contact angle of the superhydrophobic coating is ≥150°.

[0081] In some implementations, the roll-off angle of the superhydrophobic coating is ≤10°.

[0082] The technical solution of the present invention will be described in detail below with reference to specific embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this invention, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0083] In the specific embodiments described below, the measurement parameters involving raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. Temperature and time parameters are subject to acceptable deviations due to instrument testing accuracy or operational precision.

[0084] It should be noted that the information on the main experimental materials used in the following embodiments and comparative examples is shown in Table 1.

[0085] Table 1

[0086]

[0087] The main instruments and equipment used in the following embodiments and comparative examples are shown in Table 2.

[0088] Table 2

[0089]

[0090] The methods used for analyzing the surface morphology, testing the contact angle, and testing the durability of the superhydrophobic coating are as follows:

[0091] Surface morphology analysis: The surface morphology was observed by field emission scanning electron microscopy with an accelerating electric field of 5kV.

[0092] Contact angle test: The experimental sample was 3µL of deionized water. The video contact angle meter was used to automatically identify, calculate and output information such as the coating contact angle.

[0093] Durability testing: The coated sample was immersed in an ultrasonic cleaner for ultrasonic destructive testing, and the change in contact angle was measured to reflect the adhesion and robustness of the coating.

[0094] I. Preparation of Superhydrophobic Coatings

[0095] Example 1

[0096] After polishing with 1200-grit sandpaper, the aluminum alloy sample was washed alternately with anhydrous ethanol and deionized water as the base material for spraying. After cleaning, it was dried for use.

[0097] Weigh 1.2g of nano-aluminum hydroxide and 0.8g of micron-sized aluminum hydroxide into 20ml of anhydrous ethanol using an electronic balance. Then, add 1ml of hexadecyltrimethoxysilane (HDTMOS), 2ml of ultrapure water, and 1ml of acetic acid to the mixture. Stir the mixture at 750 rpm at 25°C for 300 min using a magnetic stirrer. Next, add 2ml of γ-glycidoxypropyltrimethoxysilane (KH560) to the system and continue magnetic stirring for 30 min to obtain the spray coating. The mass ratio of micron-sized aluminum hydroxide to nano-aluminum hydroxide is 1:1.5.

[0098] The spraying liquid was placed in a vacuum pump and evacuated to a vacuum level. After the gas in the solution had fully escaped, it was removed. The spraying liquid was then added to the spray gun spray bottle through a 200-mesh metal filter and sprayed onto the surface of the washed and dried aluminum alloy sample. The spraying air pump pressure was 0.4 MPa, and the vertical distance between the spray gun nozzle and the sample surface was approximately 30 cm. Multiple layers were sprayed at intervals until the coating was evenly distributed and of moderate thickness. After spraying, the sample was transferred to a forced-air drying oven and dried and cured at 80°C for 12 hours to obtain a superhydrophobic coating.

[0099] Example 2

[0100] The difference between Example 2 and Example 1 is that 0.25 ml of KH560 was added, while everything else was the same.

[0101] Example 3

[0102] The difference between Example 3 and Example 1 is that 0.5 ml of KH560 was added, while everything else was the same.

[0103] Example 4

[0104] The difference between Example 4 and Example 1 is that 1 ml of KH560 was added, while everything else was the same.

[0105] Example 5

[0106] The difference between Example 5 and Example 1 is that 4 ml of KH560 was added, while everything else is the same.

[0107] Comparative Example 1

[0108] The difference between Comparative Example 1 and Example 1 is that KH560 was not added, but everything else is the same.

[0109] The superhydrophobic coatings prepared in Examples 1-5 and Comparative Example 1 were subjected to static contact angle and ultrasonic contact angle tests after 1 hour. The results are shown in Table 3 and 4. Figure 1 As shown in the figure. The changes in contact angle and roll-off angle of the superhydrophobic coating in Example 1 over time during 1 hour of ultrasonication are shown in the figure. Figure 2 As shown in Table 3. It should be noted that... Figure 1 and Figure 2 The contact angle and roll-off angle test results are the average values ​​after 5 measurements of the superhydrophobic coating. Furthermore, the minimum roll-off angle of the superhydrophobic coating obtained in Example 1 is as follows: Figure 3 As shown, the maximum contact angle is 3°; the maximum contact angle of the superhydrophobic coating obtained in Example 1 is as follows. Figure 4 As shown, it is 157°.

[0110] Table 3

[0111]

[0112] It should be noted that the static contact angle refers to the contact angle of the superhydrophobic coating when it is not subjected to ultrasonic treatment.

[0113] From Table 3 and Figure 1 The results show that when the volume mass ratio of silane coupling agent to host material is (0.5-4) ml:2 g, the static contact angle is as high as 150° or more, indicating that the superhydrophobic coating also has excellent hydrophobicity. Furthermore, when the volume mass ratio of silane coupling agent to host material is (0.5-4) ml:2 g, the contact angle of the superhydrophobic coating only decreases slightly after 1 hour of underwater ultrasonication; this indicates that the superhydrophobic coating can still maintain good hydrophobic properties and coating integrity after 1 hour of underwater ultrasonication, demonstrating strong adhesion between the superhydrophobic coating and the substrate, and excellent durability.

[0114] Depend on Figure 2 It can be seen that when the volume mass ratio of silane coupling agent to host material is 2ml:2g, the static contact angle (CA) and roll-off angle (RA) of the superhydrophobic coating change less, and its performance is optimal.

[0115] The surface morphology of the superhydrophobic coating in Example 1 was observed using scanning electron microscopy. SEM images of the coating at magnifications of 1K, 2K, and 3K are shown below. Figure 5 , Figure 6 and Figure 7 As shown. By Figure 5-7 It can be seen that the micron-sized aluminum hydroxide particles are embedded in the lamellar spherical structure formed by the condensation of hexadecyltrimethoxysilane, and the multi-level structure achieves excellent contact angle.

[0116] Example 6

[0117] The difference between Example 6 and Example 1 is that the amount of hexadecyltrimethoxysilane (HDTMOS) added is 0.25 ml, while all other aspects are the same.

[0118] Example 7

[0119] The difference between Example 7 and Example 1 is that the amount of hexadecyltrimethoxysilane (HDTMOS) added is 0.5 ml, while all other aspects are the same.

[0120] Example 8

[0121] The difference between Example 8 and Example 1 is that the amount of hexadecyltrimethoxysilane (HDTMOS) added is 2 ml, while all other aspects are the same.

[0122] Example 9

[0123] The difference between Example 9 and Example 1 is that the amount of hexadecyltrimethoxysilane (HDTMOS) added is 4 ml, while all other aspects are the same.

[0124] Comparative Example 2

[0125] The difference between Comparative Example 2 and Example 1 is that hexadecyltrimethoxysilane (HDTMOS) was not added, while all other aspects are the same.

[0126] The contact angle and roll-off angle test results of the superhydrophobic coatings in Examples 1, 6-9, and Comparative Example 2 are shown in Table 4 and 5, respectively. Figure 8 As shown. It should be noted that Table 4 and... Figure 8 The test results for the contact angle and roll-off angle are the average values ​​after five measurements of the superhydrophobic coating.

[0127] Table 4

[0128]

[0129] It should be noted that the static contact angle refers to the contact angle of the superhydrophobic coating without ultrasonic treatment. The static roll-off angle refers to the roll-off angle of the superhydrophobic coating without ultrasonic treatment.

[0130] From Table 4 and Figure 7 The results show that when the volume-to-mass ratio of hexadecyltrimethoxysilane to the host material is ≥1ml:2g, the contact angle of the superhydrophobic coating is higher than 150° and the roll-off angle is lower than 10°, indicating that the superhydrophobic coating has excellent hydrophobicity.

[0131] Example 10

[0132] The difference between Example 10 and Example 1 is that the amount of nano aluminum hydroxide used is 1.6g, the amount of micron aluminum hydroxide used is 0.4g, and the mass ratio of micron aluminum hydroxide to nano aluminum hydroxide is 1:4.

[0133] Example 11

[0134] The difference between Example 11 and Example 1 is that the amount of nano aluminum hydroxide used is 0.8g, the amount of micron aluminum hydroxide used is 1.2g, and the mass ratio of micron aluminum hydroxide to nano aluminum hydroxide is 1.5:1.

[0135] Example 12

[0136] The difference between Example 12 and Example 1 is that the amount of nano aluminum hydroxide used is 0.4g, the amount of micron aluminum hydroxide used is 1.6g, and the mass ratio of micron aluminum hydroxide to nano aluminum hydroxide is 4:1.

[0137] Comparative Example 3

[0138] The difference between Comparative Example 3 and Example 1 is that micron-sized aluminum hydroxide was not added, and the amount of nano-aluminum hydroxide used was 2g.

[0139] Comparative Example 4

[0140] The difference between Comparative Example 4 and Example 1 is that no nano-aluminum hydroxide was added, and the amount of micron-sized aluminum hydroxide used was 2g.

[0141] The contact angle and roll-off angle test results of the superhydrophobic coatings in Examples 1, 10-12, and Comparative Examples 3-4 are shown in Table 5 and 5, respectively. Figure 9 As shown. It should be noted that Table 5 and... Figure 9 The test results for the contact angle and roll-off angle are the average values ​​after five measurements of the superhydrophobic coating.

[0142] Table 5

[0143]

[0144] It should be noted that the static contact angle refers to the contact angle of the superhydrophobic coating without ultrasonication. The static roll-off angle refers to the roll-off angle of the superhydrophobic coating without ultrasonication. In Table 5, N represents the mass ratio of micron-sized aluminum hydroxide to nano-sized aluminum hydroxide.

[0145] From Table 5 and Figure 9 The results show that when the mass ratio of micron-sized aluminum hydroxide to nano-sized aluminum hydroxide is (1-6):4, the contact angle of the superhydrophobic coating is higher than 150° and the roll-off angle is lower than 10°, indicating that the superhydrophobic coating has excellent hydrophobicity.

[0146] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a superhydrophobic coating, characterized in that, Includes the following steps: A mixture is prepared by mixing a main material with a solvent; the main material includes nano-aluminum hydroxide and micron-aluminum hydroxide. The mixture is combined with hexadecyltrimethoxysilane, ultrapure water, acetic acid and silane coupling agent to prepare a spraying solution; The superhydrophobic coating is prepared by spraying the coating liquid onto the substrate surface. The mass ratio of micron-sized aluminum hydroxide to nano-sized aluminum hydroxide in the main material is (1-6):4; the volume mass ratio of hexadecyltrimethoxysilane to the main material is ≥1 ml:2 g; the volume mass ratio of ultrapure water to the main material is (1.9-2.1) ml:2 g; the volume mass ratio of acetic acid to the main material is (0.95-1.05) ml:2 g; the silane coupling agent includes γ-glycidoxypropyltrimethoxysilane, and the volume mass ratio of the silane coupling agent to the main material is (0.5-4) ml:2 g; The superhydrophobic coating has a two-dimensional structure of lamellar spheres and particles.

2. The preparation method according to claim 1, characterized in that, The volume-to-mass ratio of the hexadecyltrimethoxysilane to the host material is (1-5) ml: 2 g.

3. The preparation method according to claim 2, characterized in that, The volume-to-mass ratio of the hexadecyltrimethoxysilane to the host material is (1-4) ml: 2 g.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The step of mixing the mixture with hexadecyltrimethoxysilane, ultrapure water, acetic acid, and a silane coupling agent includes: The mixture is stirred with the hexadecyltrimethoxysilane, the ultrapure water and the acetic acid, and then a silane coupling agent is added and stirring is continued.

5. The preparation method according to any one of claims 1 to 3, characterized in that, The spraying pressure is 0.3 MPa-0.5 MPa; and / or The spraying is performed using a spray gun, with the vertical distance between the spray gun nozzle and the substrate surface being 25cm-30cm; and / or The substrate is made of aluminum alloy.

6. The preparation method according to any one of claims 1 to 3, characterized in that, It also includes the step of drying the substrate surface after spraying.

7. The preparation method according to claim 6, characterized in that, The drying process is carried out at a temperature of 75℃-85℃ for 10h-14h.

8. A superhydrophobic coating, characterized in that, The superhydrophobic coating is prepared by any one of the preparation methods described in claims 1 to 7; the superhydrophobic coating has a two-dimensional structure of lamellar spheres and particles.

9. The superhydrophobic coating as described in claim 8, characterized in that, The static contact angle of the superhydrophobic coating is ≥150°.

10. The superhydrophobic coating as described in claim 8, characterized in that, The roll-off angle of the superhydrophobic coating is ≤10°.

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