HBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof

Abstract

The invention discloses an hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and a preparation method thereof.The preparation method comprises the steps that a polydimethylsiloxane modifier, epoxy resin, hBN powder and Al2O3 powder are added into an n-hexane solvent, and uniform suspension liquid is obtained after sufficient stirring; adding a curing agent of a polydimethylsiloxane modifier and a curing agent of epoxy resin into the suspension, fully stirring and uniformly mixing to obtain the super-hydrophobic composite coating. And uniformly spraying the super-hydrophobic composite coating on a base material, and curing to obtain the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating. The method is simple in process and low in 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, which 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 originates 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 types of superhydrophobic coatings have emerged, which have 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 coating. On the other hand, the manufacturing process of such coatings is complicated and costly, and is not suitable for large-scale industrial production. More importantly, harmful chemicals are used in some preparation methods, which 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 compounding materials with different functions, not only can the mechanical properties of the coating be effectively improved, but also its long-term 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] At present, in order to expand the application scope of super-hydrophobic coatings, it is urgent to develop a corrosion-resistant super-hydrophobic composite coating that has excellent self-cleaning properties, anti-fouling properties, mechanical stability, and is suitable for a variety of substrate materials. At the same time, this type of coating must also have the advantage of low cost to meet the needs of industrial production and large-scale application. 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 view of the deficiencies in the above-mentioned prior art. The prepared super-hydrophobic coating has good long-term anti-corrosion effect under different working conditions, and 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: A method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating comprises the following steps: S1, adding polydimethylsiloxane modifier, epoxy resin, hBN powder and Al2O3 powder into n-hexane solvent, and stirring thoroughly to obtain a uniform suspension; 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 uniformly sprayed on the base material, and after curing, a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating is obtained.

[0008] 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.

[0009] Preferably, the mass ratio of hBN powder to n-hexane solvent is (4.9-5.0):100.

[0010] Preferably, the particle size of the hBN powder is 5-10 μm.

[0011] Preferably, the mass ratio of Al2O3 powder to n-hexane solvent is (1.4-1.5):100.

[0012] Preferably, the particle size of the Al2O3 powder is 10-20 nm.

[0013] Preferably, in step S2, the mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is (1-1.1):10.

[0014] Preferably, in step S2, the mass ratio of the epoxy resin curing agent to the epoxy resin is (1-1.05):3.

[0015] Preferably, in step S3, the curing treatment temperature is 70-80° C. and the time is 1.5-2 hours.

[0016] Another technical solution of the present invention is a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, characterized in that the contact angle of the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating is 161.5°±2.02°~164.6°±2.66°, and the rolling angle is 5.8°±1.03°~35.8°±4.25°.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: 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; 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, so super-hydrophobicity is obtained; since the coating has excellent The super-hydrophobicity shows outstanding self-cleaning and anti-fouling properties. Since the super-hydrophobic composite coating has good corrosion resistance and effectively protects the base material, the network cross-linked structure formed by the polydimethylsiloxane modifier and the epoxy resin binder can absorb the external mechanical stress. The micron hBN powder serves as a micro-skeleton and anti-wear 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. At the same time, it has good flexibility and can deform simultaneously with the slight deformation of the substrate.

[0018] Furthermore, the appropriate ratio of polydimethylsiloxane to hexane can ensure that the coating has optimal hydrophobic properties while ensuring its uniform distribution and adhesion on different substrates. The appropriate ratio of epoxy resin to hexane can improve the adhesion and durability of the coating.

[0019] Furthermore, the setting of the mass ratio of hBN powder to n-hexane solvent can ensure that the coating has ideal mechanical properties and can ensure that hBN is evenly dispersed in the n-hexane solvent.

[0020] 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.

[0021] Furthermore, the mass ratio of Al2O3 powder to n-hexane solvent can ensure that the coating has ideal mechanical properties and uniformity.

[0022] Furthermore, the particle size setting of Al2O3 powder can play a key role in enhancing the mechanical stability of the coating, adjusting the surface roughness, optimizing heat resistance and chemical stability, etc. By properly selecting the particle size, the coating can not only obtain excellent wear resistance, but also improve its super hydrophobicity and processability, ensuring the application effect of the coating in a variety of environments.

[0023] Furthermore, a suitable setting of the mass ratio of the polydimethylsiloxane modifier to the curing agent can ensure that the coating has good curing effect, mechanical properties, flexibility and superhydrophobicity.

[0024] 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.

[0025] Furthermore, the temperature and time settings of the curing treatment after spraying can ensure the complete curing of the coating, optimize the mechanical properties, ensure the surface quality, and at the same time improve the production efficiency and durability of the coating.

[0026] 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.

[0027] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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 creative work.

[0029] Figure 1 The contact angle and rolling angle variation curves of the coatings prepared in Examples 2, 3, 4, 5, 6 and 7; Figure 2 Scanning electron micrographs of the coatings prepared in Examples 2, 3, 4, 5, 6 and 7; Figure 3 Bode plot and polarization curve diagram of the corrosion resistance comparison test of a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and an AA3003 aluminum plate substrate prepared in Example 3. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] 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.

[0032] 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.

[0033] In the present invention, unless otherwise specified, percentage (%) or part refers to the weight percentage or weight part relative to the composition.

[0034] In the present invention, unless otherwise specified, the components or preferred components involved can be combined with each other to form a new technical solution.

[0035] In the present invention, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "6-22" represents that all real numbers between "6-22" are listed in this document, and "6-22" is just an abbreviation of these numerical combinations.

[0036] The “range” disclosed in the present invention is in the form of a lower limit and an upper limit, which can be one or more lower limits, and one or more upper limits, respectively.

[0037] 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.

[0038] In the present invention, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the sequence. Preferably, the reaction method herein is carried out sequentially.

[0039] Unless otherwise specified, the professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present invention.

[0040] The present invention discloses a method for preparing a hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating, comprising the following steps: S1, adding polydimethylsiloxane modifier, epoxy resin, hBN powder and Al2O3 powder into n-hexane solvent, and stirring thoroughly to obtain a uniform suspension; Among them, the particle size of hBN powder is 5~10μm; the particle size of Al2O3 powder is 10~20nm.

[0041] The mass ratio of polydimethylsiloxane modifier to n-hexane solvent is (7.1~7.3):100.

[0042] The mass ratio of epoxy resin adhesive to n-hexane solvent is (2.1~2.2):100.

[0043] 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.

[0044] 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; The mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is 1:10.

[0045] The mass ratio of the epoxy resin curing agent to the epoxy resin is 1:3.

[0046] S3. Spray the super-hydrophobic composite coating evenly on the substrate material with a clean surface and no foreign matter, and cure it at a temperature of 70-80°C for 1.5-2h.

[0047] 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.

[0048] 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°.

[0049] 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, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually 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 in 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.

[0050] Example 1 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; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0051] Example 2 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0052] Example 3 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0053] Example 4 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0054] Example 5 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; 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 to mix them evenly, and obtain a super hydrophobic composite coating. ; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0055] Example 6 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0056] Example 7 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 into 7g of n-hexane solvent, and stir thoroughly to obtain a uniform suspension; Step 2: Add 0.05 g of a polydimethylsiloxane modifier curing agent and 0.05 g of an epoxy resin curing agent to the suspension obtained in step 1, stir well to mix them evenly, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.5 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0057] Example 8 Step 1: First, 0.51g polydimethylsiloxane modifier, 0.154g epoxy resin, and 0.34g particle size of 10μm hBN powder, 0.098g Al with a particle size of 20nm 2 O 3 Add the powder into 7g of n-hexane solvent and stir thoroughly to obtain a uniform Suspension; Step 2: Add 0.056g of polydimethylsiloxane modifier curing agent and 0.054g of epoxy resin curing agent Add the mixture into the suspension obtained in step 1, stir thoroughly to make it evenly mixed, and obtain a super-hydrophobic composite coating; Step 3: Use a spray gun with a nozzle diameter of 1.0 mm, spray the super-hydrophobic composite coating evenly on the 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.

[0058] The coatings prepared in Examples 2 to 7 were taken and the contact angle and rolling angle thereof were measured using a contact angle measuring instrument. The contact angle and rolling angle were as follows: Figure 1As 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°, which shows that the addition of nano-scale ceramic particles has a significant effect on improving the rolling angle of the super-hydrophobic coating; The coatings prepared in Examples 2 to 7 were subjected to surface morphology analysis. Figure 2 As shown. It can be seen from the figure that the super hydrophobic coating has a multi-level micro-nano structure, which enables it to produce an air layer in the solution, thereby having good corrosion resistance. The contact angle of the coating obtained in Example 8 is 160.1°±1.65°, and the rolling angle is 6.0°±1.04°. In particular, the hydrophobicity of Examples 4 to 7 is affected due to the agglomeration of nanoparticles.

[0059] The following is a comparative test between the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface and the ordinary AA3003 aluminum plate: 1. Hydrophobicity comparison The contact angle and rolling angle of the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface 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 attached to the surface 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°. 2. Comparison of self-cleaning performance 0.8g of standard sand was sprinkled at an inclination angle of 8° on the exposed surface of the AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface and the 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 AA3003 aluminum plate with the super-hydrophobic composite coating attached to the surface, while the sand particles on the ordinary AA3003 aluminum plate require 6250μL of water to carry away.

[0060] 3. Comparison of anti-pollution performance 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 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%.

[0061] 4. Corrosion resistance comparison The corrosion resistance of the AA3003 aluminum plate with the super-hydrophobic composite coating and the ordinary AA3003 aluminum plate was compared in a standard three-electrode system with an exposure 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. EIS measurements were performed in the frequency range of 100 kHz to 0.01 Hz by applying a 10 mV sinusoidal perturbation. Figure 3 As 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; 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 3 As shown in Figure 2, 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 attached to 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.

[0062] The super hydrophobic composite coating of the present invention is subjected to mechanical stability test and multi-substrate universality test: 1. Mechanical stability test: Superhydrophobic materials usually have a unique micro-nano 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°, the SA was 9.9°±0.60°, and the hydrophobicity did not change much.

[0063] Table 1 Contact angles of superhydrophobic coatings on different substrate surfaces

[0064] 2. Multi-substrate universality test: The universality of multi-substrates was evaluated by testing the surface wettability of the superhydrophobic composite coating on wood chips, plastics, filter paper, sandpaper and glass slides. After measurement, all samples showed superhydrophobicity, and the specific contact angles are shown in Table 1.

[0065] 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 of the polydimethylsiloxane modifier be added. After fully stirring to make the mixture uniform, the super-hydrophobic composite coating of the present invention can be obtained. The process is simple and the cost is low.

[0066] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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, adding polydimethylsiloxane modifier, epoxy resin, hBN powder and Al2O3 powder into n-hexane solvent, and stirring thoroughly to obtain a uniform suspension; 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 uniformly 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 the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 1, characterized in that: 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 the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 2, characterized in that: The mass ratio of hBN powder to n-hexane solvent is (4.9~5.0):

100.

4. The method for preparing the hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating according to claim 3, characterized in that: The particle size of hBN powder is 5~10μm.

5. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof according to claim 2, characterized in that: The mass ratio of Al2O3 powder to n-hexane solvent is (1.4~1.5):

100.

6. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof according to claim 5, characterized in that: The particle size of Al2O3 powder is 10~20nm.

7. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof according to claim 1, characterized in that: In step S2, the mass ratio of the curing agent of the polydimethylsiloxane modifier to the polydimethylsiloxane modifier is (1-1.1):

10.

8. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof according to claim 1, characterized in that: In step S2, the mass ratio of the epoxy resin curing agent to the epoxy resin is (1-1.05):

3.

9. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating and preparation method thereof according to claim 1, characterized in that: In step S3, the curing treatment temperature is 70-80° C. and the time is 1.5-2 hours.

10. The hBN / Al2O3-based corrosion-resistant super-hydrophobic composite coating prepared by the method according to claim 1, characterized in that: The contact angle of the hBN / Al2O3-based corrosion-resistant superhydrophobic composite coating is 161.5°±2.02°~164.6°±2.66°, and the rolling angle is 5.8°±1.03°~35.8°±4.25°.

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