A hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and its preparation method

Abstract

The invention discloses a kind of hBN / Al2O3Based corrosion-resistant super-hydrophobic composite coating and preparation method thereof, polydimethylsiloxane modifier, epoxy resin, hBN powder, Al2O3Powder is added in n-hexane solvent, and uniform suspension is obtained after sufficient stirring;The curing agent of polydimethylsiloxane modifier and the curing agent of epoxy resin are added in suspension, and after sufficient stirring, it is mixed uniformly to obtain super-hydrophobic composite coating;Super-hydrophobic composite coating is evenly sprayed on base material, and hBN / Al2O3Based corrosion-resistant super-hydrophobic composite coating is obtained after solidification.The present invention has simple procedure and low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrophobic materials, and specifically relates to a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and a preparation method thereof. The coating is suitable for a variety of industrial protective surfaces and has excellent super-hydrophobicity, self-cleaning, anti-fouling, anti-icing and corrosion resistance. Background Art

[0002] Superhydrophobic materials exhibit a strong hydrophobic effect because the contact angle of surface droplets is greater than 150° and the rolling angle is less than 10°. This material can significantly reduce the adhesion between water droplets and solid surfaces, giving it outstanding self-cleaning, anti-fouling, anti-icing and corrosion resistance. Superhydrophobicity stems from the synergistic effect of surface micro-nanostructures and low-surface-energy substances, similar to the "lotus effect" on the surface of lotus leaves in nature. In recent years, with the in-depth study of the excellent properties of superhydrophobic materials, various superhydrophobic coatings have emerged, with important application prospects in many fields such as construction, transportation, electronic equipment, textiles and biomedicine.

[0003] However, existing super-hydrophobic coatings still face a series of technical difficulties. On the one hand, their microstructures are often fragile and easily damaged by external factors such as friction and impact, resulting in insufficient mechanical strength and durability of the coatings. On the other hand, the manufacturing process of such coatings is complex and costly, making them unsuitable for large-scale industrial production. More importantly, some preparation methods use harmful chemicals that cannot meet the increasingly stringent environmental protection requirements. These factors limit the further promotion and application of super-hydrophobic coatings in the industrial field.

[0004] In order to circumvent the above problems, the research on composite super-hydrophobic coatings has gradually become a hot topic. By combining materials with different functions, not only can the mechanical properties of the coating be effectively improved, but also its long-term and stable super-hydrophobicity can be ensured. For example, combining inorganic nanoparticles with organic polymer materials can significantly improve the wear resistance, chemical stability and service life of the coating. At the same time, this type of composite coating can still maintain a good super-hydrophobic effect under different environmental conditions, such as changes in humidity and pH, showing strong environmental adaptability.

[0005] To expand the application range of superhydrophobic coatings, there is an urgent need to develop corrosion-resistant superhydrophobic composite coatings that combine excellent self-cleaning properties, anti-fouling properties, mechanical stability, and compatibility with a variety of substrate materials. At the same time, such coatings must also be low-cost to accommodate industrial production and large-scale applications. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and a preparation method thereof in response to the deficiencies in the above-mentioned prior art. The prepared super-hydrophobic coating has good long-term anti-corrosion effect under different working conditions, which is used to solve the technical problem of poor corrosion resistance of existing super-hydrophobic coatings.

[0007] The present invention adopts the following technical solutions:

[0008] A method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating comprises the following steps:

[0009] S1. Add polydimethylsiloxane modifier, epoxy resin, hBN powder, and Al2O3 powder into n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0010] S2, adding a curing agent of a polydimethylsiloxane modifier and a curing agent of an epoxy resin to the suspension obtained in step S1, stirring them thoroughly to mix them evenly to obtain a super-hydrophobic composite coating;

[0011] S3. The super-hydrophobic composite coating is evenly sprayed on the base material, and after curing, a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating is obtained.

[0012] Preferably, in step S1, the mass ratio of the polydimethylsiloxane modifier to the n-hexane solvent is (7.1-7.2):100; the mass ratio of the epoxy resin binder to the n-hexane solvent is (2.1-2.2):100.

[0013] Preferably, the mass ratio of hBN powder to n-hexane solvent is (4.9-5.0):100.

[0014] Preferably, the particle size of the hBN powder is 5-10 μm.

[0015] Preferably, the mass ratio of Al2O3 powder to n-hexane solvent is (1.4-1.5):100.

[0016] Preferably, the particle size of the Al2O3 powder is 10-20 nm.

[0017] Preferably, in step S2, the mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is (1-1.1):10.

[0018] Preferably, in step S2, the mass ratio of the epoxy resin curing agent to the epoxy resin is (1-1.05):3.

[0019] Preferably, in step S3, the curing treatment temperature is 70-80° C. and the curing time is 1.5-2 hours.

[0020] Another technical solution of the present invention is a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, characterized in that the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating has a contact angle of 161.5°±2.02°~164.6°±2.66° and a rolling angle of 5.8°±1.03°~35.8°±4.25°.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] A method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, wherein micron-sized hBN powder is used as a micro-skeleton and anti-wear bearing particles, nano-sized Al2O3 powder is used as a reinforcing particle, a curing agent of a polydimethylsiloxane modifier is used to promote the curing of the polydimethylsiloxane modifier, and the cured polydimethylsiloxane modifier and epoxy resin binder are coated on the surface of the hBN and Al2O3 powders to form a network cross-linked structure; the micron-sized hBN powder and nano-sized Al2O3 powder construct a micro-nano rough structure, and the surface energy of the polydimethylsiloxane modifier is low, thereby obtaining super-hydrophobicity; because the coating has excellent The super-hydrophobicity exhibits outstanding self-cleaning and anti-fouling properties. Since the super-hydrophobic composite coating has good corrosion resistance and effectively protects the substrate material, the network cross-linked structure formed by the polydimethylsiloxane modifier and the epoxy resin binder can absorb external mechanical stress. The micron hBN powder serves as a micro-skeleton and anti-wear load-bearing particles, so the coating is not easy to fall off and has good mechanical stability. The network cross-linked structure formed by the polydimethylsiloxane modifier and the epoxy resin binder has good adhesion and can adapt to different types of substrates. It also has good flexibility and can deform simultaneously with the slight deformation of the substrate.

[0023] Furthermore, a suitable ratio of polydimethylsiloxane to n-hexane ensures optimal hydrophobicity while ensuring uniform distribution and adhesion on various substrates. A suitable ratio of epoxy resin to n-hexane improves the adhesion and durability of the coating.

[0024] Furthermore, the mass ratio of hBN powder to n-hexane solvent can ensure that the coating has ideal mechanical properties and that hBN is evenly dispersed in the n-hexane solvent.

[0025] Furthermore, the particle size setting of the micron-sized hBN powder can not only provide good mechanical support and wear resistance for the coating, but also optimize the surface roughness of the coating, ensuring excellent superhydrophobicity, thermal conductivity and chemical stability.

[0026] Furthermore, the mass ratio of Al2O3 powder to n-hexane solvent is set to ensure that the coating has ideal mechanical properties and uniformity.

[0027] Furthermore, the particle size of the Al2O3 powder plays a key role in enhancing the coating's mechanical stability, regulating surface roughness, and optimizing heat resistance and chemical stability. By properly selecting the particle size, the coating not only achieves excellent wear resistance but also improves its superhydrophobicity and workability, ensuring its effectiveness in a variety of environments.

[0028] Furthermore, a suitable mass ratio of the polydimethylsiloxane modifier to the curing agent can ensure that the coating has good curing effect, mechanical properties, flexibility and superhydrophobicity.

[0029] Furthermore, the mass ratio of the epoxy resin binder to the curing agent is set so that the coating is completely cross-linked during the curing process, and its mechanical strength and corrosion resistance are optimized, and the bonding force between the coating and the substrate is increased.

[0030] Furthermore, the temperature and time settings for the post-spray curing treatment can ensure complete curing of the coating, optimize mechanical properties, guarantee surface quality, and improve production efficiency and coating durability.

[0031] In summary, the super-hydrophobic composite coating prepared by the present invention has good self-cleaning properties, anti-fouling properties, corrosion resistance, mechanical stability, and multi-substrate universality.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 The contact angle and sliding angle variation curves of the coatings prepared in Examples 2, 3, 4, 5, 6 and 7 are shown;

[0035] Figure 2 Scanning electron micrographs of the coatings prepared in Examples 2, 3, 4, 5, 6, and 7;

[0036] Figure 3 Bode plots and polarization curves from a comparative corrosion resistance test of a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and an AA3003 aluminum plate substrate prepared in Example 3. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] In the present invention, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0039] In the present invention, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0040] In the present invention, unless otherwise specified, percentages (%) or parts refer to percentages by weight or parts by weight relative to the composition.

[0041] In the present invention, unless otherwise specified, the components involved or their preferred components can be combined with each other to form a new technical solution.

[0042] In this disclosure, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6-22" indicates that all real numbers between "6-22" are listed herein, and "6-22" is merely an abbreviation for these numerical combinations.

[0043] The "range" disclosed in the present invention is in the form of lower limit and upper limit, which can be one or more lower limits, and one or more upper limits respectively.

[0044] In the present invention, the term "and / or" used herein refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0045] In the present invention, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the order. Preferably, the reaction method herein is carried out sequentially.

[0046] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention.

[0047] The present invention provides a method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, comprising the following steps:

[0048] S1. Add polydimethylsiloxane modifier, epoxy resin, hBN powder, and Al2O3 powder into n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0049] Among them, the particle size of hBN powder is 5~10μm; the particle size of Al2O3 powder is 10~20nm.

[0050] The mass ratio of polydimethylsiloxane modifier to n-hexane solvent is (7.1~7.3):100.

[0051] The mass ratio of epoxy resin adhesive to n-hexane solvent is (2.1~2.2):100.

[0052] Among them, the mass ratio of hBN powder to n-hexane solvent is (4.9~5.0):100; the mass ratio of Al2O3 powder to n-hexane solvent is (1.4~1.5):100.

[0053] S2, adding a curing agent of a polydimethylsiloxane modifier and a curing agent of an epoxy resin to the suspension obtained in step S1, stirring them thoroughly to mix them evenly to obtain a super-hydrophobic composite coating;

[0054] The mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is 1:10.

[0055] The mass ratio of epoxy resin curing agent to epoxy resin is 1:3.

[0056] S3. Spray the super-hydrophobic composite coating evenly on a substrate material with a clean surface free of foreign matter, and cure it at a temperature of 70-80°C for 1.5-2 hours.

[0057] The nozzle diameter of the spray gun used for spraying is 1.0~1.5mm, the pressure is less than 0.7 MPa, and the distance is 15~17cm.

[0058] The present invention provides a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating with a contact angle of 161.5°±2.02°~164.6°±2.66° and a rolling angle of 5.8°±1.03°~35.8°±4.25°.

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0060] Example 1

[0061] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin, and 0.35g of hBN powder with a particle size of 5μm into 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0062] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0063] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0064] Example 2

[0065] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin, 0.35g of hBN powder with a particle size of 5μm, and 0.05g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0066] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0067] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0068] Example 3

[0069] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin binder, 0.35g of hBN powder with a particle size of 5μ, and 0.1g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0070] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0071] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0072] Example 4

[0073] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin, 0.35g of hBN powder with a particle size of 5μm, and 0.15g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0074] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0075] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0076] Example 5

[0077] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin, 0.35g of hBN powder with a particle size of 5μm, and 0.2g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0078] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir thoroughly and mix them evenly to obtain a super-hydrophobic composite coating.

[0079] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0080] Example 6

[0081] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin binder, 0.35g of hBN powder with a particle size of 5μm, and 0.25g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0082] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0083] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0084] Example 7

[0085] Step 1: First, add 0.5g of polydimethylsiloxane modifier, 0.15g of epoxy resin, 0.35g of hBN powder with a particle size of 5μm, and 0.3g of Al2O3 powder with a particle size of 10nm to 7g of n-hexane solvent and stir thoroughly to obtain a uniform suspension;

[0086] Step 2: Add 0.05 g of polydimethylsiloxane modifier curing agent and 0.05 g of epoxy resin curing agent to the suspension obtained in step 1, stir well and mix them evenly to obtain a super-hydrophobic composite coating;

[0087] Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 15 cm under a pressure of 0.7 MPa, and cure it at 70°C for 1.5 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0088] Example 8

[0089] Step 1: First, 0.51g polydimethylsiloxane modifier, 0.154g epoxy resin, 0.34g particle size 10μm hBN powder, 0.098g Al with a particle size of 20nm 2 O 3 The powder was added to 7g of n-hexane solvent and stirred thoroughly to obtain a uniform suspension;

[0090] Step 2: Add 0.056g of polydimethylsiloxane modifier curing agent and 0.054g of epoxy resin curing agent Add the suspension obtained in step 1, stir thoroughly to mix evenly, and obtain a super-hydrophobic composite coating;

[0091] Step 3: Use a spray gun with a nozzle diameter of 1.0 mm, spray the super-hydrophobic composite coating evenly on an AA3003 aluminum plate with a clean surface and no foreign matter at a distance of 17 cm under a pressure of 0.65 MPa, and cure it at 80°C for 2 hours to obtain an AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface.

[0092] The coatings prepared in Examples 2 to 7 were measured for contact angle and rolling angle using a contact angle meter. The contact angle and rolling angle were as follows: Figure 1 As shown in the figure, it can be seen that the super-hydrophobic coating prepared in Example 3 has the best super-hydrophobicity, with a contact angle of 164.6°±2.66° and a rolling angle of 5.8°±1.03°; the contact angle of the coating obtained in Example 1 is 161.5°±2.02°, and the rolling angle is 35.8°±4.25°. It can be seen that the addition of nano-ceramic particles has a significant effect on improving the rolling angle of the super-hydrophobic coating;

[0093] Take the coatings prepared in Examples 2 to 7 and analyze their surface morphology. Figure 2 As shown in the figure, the super-hydrophobic coating has a multi-level micro-nanostructure, which enables it to form an air layer in the solution, thus having good corrosion resistance. The coating obtained in Example 8 has a contact angle of 160.1°±1.65° and a rolling angle of 6.0°±1.04°. In particular, the hydrophobicity of Examples 4 to 7 was affected due to the agglomeration of nanoparticles.

[0094] The following is a comparative test between the AA3003 aluminum plate with the super-hydrophobic composite coating and the ordinary AA3003 aluminum plate:

[0095] 1. Hydrophobicity comparison

[0096] The contact angle and rolling angle of the AA3003 aluminum plate with the super-hydrophobic composite coating and the ordinary AA3003 aluminum plate were tested using a contact angle meter. The contact angle of the AA3003 aluminum plate with the super-hydrophobic composite coating was 164.6°±2.66°, and the rolling angle was 5.8°±1.03°. The contact angle of the ordinary AA3003 aluminum plate was 73.6°±2.4°, and the rolling angle was greater than 90°.

[0097] 2. Comparison of self-cleaning performance

[0098] 0.8g of standard sand was sprinkled at an inclination angle of 8° on the exposed surface of an AA3003 aluminum plate with the super-hydrophobic composite coating and an ordinary AA3003 aluminum plate. Then, water droplets were dripped from 7cm above the sample. The dripping water droplets can carry away the sand particles on the surface. After measurement, only 250μL of water is needed to carry away the sand particles on the surface of the AA3003 aluminum plate with the super-hydrophobic composite coating, while the sand particles on the ordinary AA3003 aluminum plate require 6250μL of water to carry away.

[0099] 3. Comparison of anti-pollution performance

[0100] The AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface and the ordinary AA3003 aluminum plate were immersed in milk, cola, and orange juice at the same time. After 48 hours, the proportion of the area of ​​the contaminated surface area to the total area was compared. After immersion in milk for 48 hours, the contaminated area of ​​the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface was 0%, and the contaminated area of ​​the ordinary AA3003 aluminum plate was 98%. After immersion in cola for 48 hours, the contaminated area of ​​the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface was 0%, and the contaminated area of ​​the ordinary AA3003 aluminum plate was 93%. After immersion in orange juice for 48 hours, the contaminated area of ​​the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface was 0%, and the contaminated area of ​​the ordinary AA3003 aluminum plate was 89%.

[0101] 4. Corrosion resistance comparison

[0102] The corrosion resistance of AA3003 aluminum plate with super hydrophobic composite coating and ordinary AA3003 aluminum plate was compared in a standard three-electrode system with an exposed area of ​​1 cm 2 As the working electrode, saturated calomel electrode (SCE) as the reference electrode, platinum sheet as the counter electrode, all samples were immersed in 3.5wt.% NaCl solution for 30 min to reach a stable open circuit potential ( E OCP ), and then electrochemical impedance spectroscopy (EIS) and polarization tests were performed. By applying a 10 mV sinusoidal perturbation, EIS measurements were performed in the frequency range of 100 kHz to 0.01 Hz, as shown in Figure 2. Figure 3As shown, the low-frequency |Z| of the AA3003 aluminum plate with the super-hydrophobic composite coating attached to its surface 0.01 Hz 5.0×10 5 Ω·cm 2 , the low frequency |Z| of ordinary AA3003 aluminum plate 0.01 Hz 2.2×10 3 Ω·cm 2 , the difference between the two is 2 orders of magnitude, indicating that the super-hydrophobic coating has excellent anti-corrosion properties;

[0103] At -0.3 V SCE ~0.3V SCE and E OCP Potentiodynamic polarization (PDP) was performed at a scan rate of 0.2 mV / s within the potential range, and the polarization curves were fitted using the Tafel extrapolation method, as shown in Figure 2. Figure 3 As shown in the figure, the corrosion current density of the AA3003 aluminum plate with the super-hydrophobic composite coating on its surface is 5.21×10 -10 A.cm -2 The corrosion current density of ordinary AA3003 aluminum plate is 2.67×10 -7 A.cm -2 The difference between the two is 2 orders of magnitude. The corrosion potential of the AA3003 aluminum plate with the super-hydrophobic composite coating on the surface is -0.59 V, and the corrosion current potential of the ordinary AA3003 aluminum plate is -0.65 V, indicating that the super-hydrophobic coating exhibits outstanding corrosion resistance.

[0104] The mechanical stability test and multi-substrate universality test of the super-hydrophobic composite coating of the present invention are as follows:

[0105] 1. Mechanical stability test: Superhydrophobic materials usually have a unique micro-nano-level rough structure and are easily damaged under external forces. Therefore, the mechanical stability of artificial superhydrophobic coatings is an important indicator that determines their wide application. In order to evaluate the mechanical robustness of the coating, a sandpaper wear test was carried out. The AA3003 aluminum plate with the superhydrophobic composite coating attached to the surface was placed face down on sandpaper (2000 mesh) and then rubbed on the sandpaper at a constant speed of 5 mm / s. The calculated pressure was 1.33 kPa, and a linear reciprocating distance of 10 cm (total distance of 20 cm) was defined as a friction cycle. After several cycles of wear, the corresponding contact angle and rolling angle of the coating sample were measured after each friction cycle to evaluate the changes in the wettability and mechanical stability of the coating. After a 300 cm sandpaper wear test, the WCA of the coating was 155.6°±3.30°, and the SA was 9.9°±0.60°, and the hydrophobicity did not change much.

[0106] Table 1 Contact angles of superhydrophobic coatings on different substrates

[0107]

[0108] 2. Multi-substrate universality test: The multi-substrate universality was evaluated by testing the surface wettability of the superhydrophobic composite coating on wood chips, plastic, filter paper, sandpaper, and glass slides. After measurement, all samples showed superhydrophobicity. The specific contact angles are shown in Table 1.

[0109] In summary, the present invention provides a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and a preparation method thereof. It only requires that a specific proportion of polydimethylsiloxane modifier, epoxy resin binder, hBN powder, and Al2O3 powder be placed in a n-hexane solvent and stirred, and then a certain amount of a curing agent for the polydimethylsiloxane modifier be added. After sufficient stirring to mix them evenly, the super-hydrophobic composite coating of the present invention can be obtained. The process is simple and the cost is low.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, characterized in that: The following steps are involved: S1. Add polydimethylsiloxane modifier, epoxy resin, hBN powder, and Al2O3 powder to n-hexane solvent and stir thoroughly to obtain a uniform suspension. The mass ratio of hBN powder to n-hexane solvent is (4.9-5.0):

100. S2, adding a curing agent of a polydimethylsiloxane modifier and a curing agent of an epoxy resin to the suspension obtained in step S1, stirring them thoroughly to mix them evenly to obtain a super-hydrophobic composite coating; S3. The super-hydrophobic composite coating is evenly sprayed on the base material, and after curing, a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating is obtained.

2. The method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, wherein: In step S1, the mass ratio of the polydimethylsiloxane modifier to the n-hexane solvent is (7.1-7.2):100; the mass ratio of the epoxy resin binder to the n-hexane solvent is (2.1-2.2):

100.

3. The method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, wherein: The particle size of hBN powder is 5~10μm.

4. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 2, wherein: The mass ratio of Al2O3 powder to n-hexane solvent is (1.4~1.5):

100.

5. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 4, wherein: The particle size of Al2O3 powder is 10~20nm.

6. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, wherein: In step S2, the mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is (1-1.1):

10.

7. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, wherein: In step S2, the mass ratio of the epoxy resin curing agent to the epoxy resin is (1-1.05):

3.

8. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, wherein: In step S3, the curing temperature is 70-80° C. and the curing time is 1.5-2 hours.

9. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating prepared by the method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, characterized in that: The contact angle of the hBN / Al2O3-based corrosion-resistant superhydrophobic composite coating is 161.5°~164.6°, and the sliding angle is 5.8°±1.03°~35.8°±4.25°.

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