A modified hexagonal boron nitride / epoxy resin anti-fouling coating and a preparation method thereof

Abstract

The application relates to the technical field of surface protection, in particular to a modified hexagonal boron nitride / epoxy resin scale inhibition coating and a preparation method thereof, and the preparation method comprises the following steps: S1, substrate pretreatment; S2, modified nano filler preparation, comprising: modified nano SiO2 preparation and modified h-BN preparation; and S3, modified h-BN / SiO2 / EP coating preparation. Through the synergistic effect of the modified nano SiO2 and the modified h-BN, the scale inhibition performance of the epoxy coating is remarkably improved, and the modified h-BN / SiO2 / EP coating prepared by the method provided by the application has high hydrophobicity, and the water contact angle can reach 135.4 degrees.

Description

Technical Field

[0001] This invention relates to the field of surface protection technology, and more specifically, to a modified hexagonal boron nitride / epoxy resin anti-fouling coating and its preparation method. Background Technology

[0002] Scaling is a long-standing problem in industrial production. Scaling not only reduces the heat transfer efficiency of equipment and increases energy consumption, but it can also lead to pipe blockage and equipment corrosion, seriously affecting normal production operations. Therefore, developing efficient scale inhibition technologies is of significant practical importance.

[0003] Epoxy resin (EP) is often used as a matrix material for coatings due to its excellent adhesion, corrosion resistance, and mechanical properties. However, pure epoxy resin coatings suffer from drawbacks such as high internal stress, high brittleness, and poor impact resistance, limiting their application in scale prevention and corrosion protection. To improve coating performance, researchers typically introduce functional fillers to enhance the physical and chemical properties of the coating. Hexagonal boron nitride (h-BN) has a layered structure and possesses good thermal stability, chemical inertness, and lubricity, but its high specific surface area and van der Waals forces easily lead to its agglomeration in coatings, affecting coating performance. Therefore, surface modification of h-BN is key to improving its dispersibility in coatings. Nano-silica (SiO2), as a common inorganic filler, has a high specific surface area and good reinforcing and toughening effects, but its single modification effect is limited.

[0004] Currently, research on the synergistic modification of epoxy coatings with h-BN and nano-SiO2 mainly focuses on corrosion resistance and wear resistance, while research on their scale inhibition properties is relatively limited. Therefore, developing a modified hexagonal boron nitride / epoxy resin scale inhibition coating with excellent scale inhibition properties has significant theoretical and practical value. Summary of the Invention

[0005] The purpose of this invention is to provide a modified hexagonal boron nitride / epoxy resin scale inhibitor coating and its preparation method. Through the synergistic effect of modified nano-SiO2 and modified h-BN, the scale inhibitor performance of the epoxy coating is significantly improved. The modified h-BN / SiO2 / EP coating prepared by the method provided by this invention has high hydrophobicity, and its water contact angle can reach 135.4°.

[0006] To achieve the above objectives, the present invention is implemented through the following technical methods:

[0007] In a first aspect, the present invention provides a method for preparing a modified hexagonal boron nitride / epoxy resin scale inhibitor coating, comprising the following steps:

[0008] S1. Substrate pretreatment: After the aluminum plate is polished to a rough surface, it is ultrasonically cleaned in anhydrous ethanol.

[0009] S2. Preparation of modified nanofillers, including the following steps:

[0010] a. Preparation of modified nano-SiO2: 0.1-0.5g of nano-SiO2, 2-7g of KH550 and 100g of anhydrous ethanol were mixed and ultrasonically dispersed at 30-50℃ and 40-60kHz for 3h. Then, 8g of ultrapure water was added and heated and magnetically stirred at 80℃ for 4h. After heating and stirring, the mixture was centrifuged, vacuum filtered and then vacuum dried to obtain modified nano-SiO2.

[0011] b. Preparation of modified h-BN: 0.3-1.0 g h-BN and 200 g ultrapure water were mixed and ultrasonically dispersed at a temperature of 30-50 °C and a frequency of 40-60 kHz for 0.5 h. Then, 0.1-0.5 g dopamine and 0.1-0.3 g Tris were added and magnetically stirred for 24 h. After magnetic stirring, the mixture was vacuum filtered, washed, and then vacuum dried to obtain modified h-BN.

[0012] S3. Preparation of modified h-BN / SiO2 / EP coating: 2g epoxy resin, 10g ethyl acetate, 0.01-0.1g modified nano-SiO2 and 0.01-0.1g modified h-BN are mixed and ultrasonically dispersed at a temperature of 30-50℃ and a frequency of 40-60kHz for 0.5h. Then 1g polyamide resin is added and ultrasonically dispersed for 0.5h. The mixture is then sprayed onto the surface of a pretreated aluminum plate and cured. After cooling to room temperature (22-26℃), the modified h-BN / SiO2 / EP coating is obtained.

[0013] In the preferred embodiment, the ultrasonic cleaning time in step S1 is 10 minutes.

[0014] In the preferred embodiment, the rotation speed of the magnetic stirring in step a is 100 rpm, and the rotation speed of the magnetic stirring in step b is 100 rpm.

[0015] In the preferred embodiment, the centrifugation speed in step S2 is 1000 rpm and the time is 5 min; the vacuum filtration time is 0.5 min; and the vacuum drying time is 24 h and the temperature is 80℃.

[0016] In the preferred embodiment, the spraying conditions in step S3 are: spraying at room temperature (22-26°C) and at 0.6 MPa; and the curing conditions are: a temperature of 150°C and a time of 60 min.

[0017] In the preferred embodiment, step b involves washing with ultrapure water, and the washing is performed 5 times.

[0018] In the preferred embodiment, the aluminum plate in step S1 has dimensions of 20mm × 80mm × 1mm.

[0019] In a second aspect, the present invention provides a modified hexagonal boron nitride / epoxy resin scale inhibitor coating prepared by any of the above-described preparation methods.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. Improved Scale Inhibition Performance: The modified hexagonal boron nitride / epoxy resin scale inhibitor coating (modified h-BN / SiO2 / EP coating) prepared in this invention exhibits lower scale formation compared to the SiO2 / EP coating and the modified h-BN / EP coating. When the coating is immersed in a supersaturated CaCO3 solution for 360 hours, the scale formation on the surface of the modified h-BN / SiO2 / EP coating is 1.368 mg / cm³. 2 The scaling amounts on the surfaces of the SiO2 / EP coating and the modified h-BN / EP coating were 2.641 mg / cm³, respectively. 2 and 2.095 mg / cm 2 The modified h-BN / SiO2 / EP coating showed a scale inhibition rate of 48.2% and 34.7% compared to the SiO2 / EP coating, effectively improving the scale inhibition performance of the epoxy coating.

[0022] 2. Microstructure Optimization: The CaCO3 crystals on the surface of the modified h-BN / SiO2 / EP coating exhibit a sporadic distribution, with significantly lower crystal quantity and packing density compared to the SiO2 / EP coating and the modified h-BN / EP coating. Furthermore, in some localized areas, the CaCO3 crystals form a multilayered structure with an irregular shape. This indicates that the coating has a more significant inhibitory effect on CaCO3 crystal growth, effectively limiting the nucleation and growth of CaCO3 crystals.

[0023] 3. Improved Chemical Properties: The introduction of modified h-BN and modified nano-SiO2 reduces the free energy of the coating surface, thereby reducing the adsorption and growth of CaCO3 crystals on the coating surface. In particular, the chemical inertness and low surface energy of modified h-BN further enhance the scale inhibition performance of the coating.

[0024] 4. Advantages of crystal form control: The addition of modified h-BN induces the formation of thermodynamically unstable CaCO3 crystal forms (aragonite and aragonite) on the coating surface. These unstable CaCO3 crystal forms have relatively high solubility in water and poor stability, making it difficult to form large-scale, densely packed scale layers on the coating surface. Under certain conditions, they may redissolve back into the solution, thereby effectively reducing scale accumulation and playing a scale inhibition role. Attached Figure Description

[0025] Figure 1Schematic diagrams illustrating the preparation processes of nano-SiO2 modification, h-BN modification, and modified h-BN / SiO2 / EP coatings; among which, Figure 1 a is a schematic diagram of the nano-SiO2 modification process; Figure 1 b is a schematic diagram of the h-BN modification process; Figure 1 c is a schematic diagram of the preparation process of the modified h-BN / SiO2 / EP coating.

[0026] Figure 2 The images show the infrared spectra of nano-SiO2 before and after modification.

[0027] Figure 3 The images show the infrared spectra of h-BN before and after modification.

[0028] Figure 4 Infrared spectra of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating.

[0029] Figure 5 SEM analysis and water contact angle diagrams of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating.

[0030] Figure 6 Energy dispersive spectroscopy (EDS) analysis was performed on different coatings; among them, Figure 6 a represents a SiO2 / EP coating; Figure 6 b represents the SEM analysis and water contact angle of the modified h-BN / EP coating; Figure 6 c represents the SEM analysis and water contact angle of the modified h-BN / SiO2 / EP coating.

[0031] Figure 7 The graph shows the trend of scale formation on the surface of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating over time.

[0032] Figure 8 SEM images of the SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating after 48 hours of scaling.

[0033] Figure 9 Infrared spectra of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating after 48 hours of scaling.

[0034] Figure 10 XRD patterns of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating after 48 hours of scaling.

[0035] Figure 11 This is a schematic diagram of the scale inhibition mechanism of the coating; where, Figure 11 a represents a SiO2 / EP coating; Figure 11 b represents the modified h-BN / EP coating; Figure 11 c represents the modified h-BN / SiO2 / EP coating. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0037] Explanation of the source of raw materials used in this invention:

[0038] The main experimental materials and reagents used in the following examples are as follows: 6061 aluminum plate (80mm×80mm×1mm), Wuxi Baojing Aluminum Co., Ltd.; nano-SiO2 (nanoscale), Guangdong Hongke Chemical Raw Materials Co., Ltd.; dopamine (99% purity), Hefei Bomei Biotechnology Co., Ltd.; hexagonal boron nitride (h-BN, nanoscale), Shanghai Yaoge Alloy Materials Co., Ltd.; epoxy resin (EP, model E44) and polyamide resin (651), Shandong Yousuo Chemical Technology Co., Ltd.; tris(hydroxymethyl)aminomethane (Tris, analytical grade), anhydrous ethanol (analytical grade), sodium bicarbonate (analytical grade) and calcium nitrate tetrahydrate (analytical grade), Sinopharm Chemical Reagent Co., Ltd.; ethyl acetate (analytical grade), Shanghai Maclean Biochemical Technology Co., Ltd.; silane coupling agent KH550 (industrial grade), Dongguan Lvwei Plastic Products Co., Ltd.; ultrapure water, prepared in the laboratory.

[0039] Description of the equipment used in this invention:

[0040] The main instruments and equipment used in this invention are as follows: Electronic balance (WTD30002), Hangzhou Wante Weighing Instrument Co., Ltd.; Multifunctional ultrasonic cleaner (YL0404-40), Yunyi Ultrasonic (Shenzhen) Co., Ltd.; Oil-free air compressor (DCQE1320-10LE), Jiangsu Dongcheng Electric Tools Co., Ltd.; Super constant temperature water bath (DF-101S), Changzhou Pugong Instrument Manufacturing Co., Ltd.; Spray gun (R2-F), Shanghai Anest Iwata Coating Machinery Co., Ltd.; Electric heating drying oven (101-1AB), Tianjin Tester Instrument Co., Ltd.; Magnetic stirrer (HJ-2A), Jintan Chengdong Xinrui Instrument Factory; Scanning electron microscope (SEM, EM-30), Korea Coolsem Corporation; Surface tension and contact angle measuring instrument (SL200KS), American Kono Industrial Co., Ltd.; Fourier transform infrared spectrometer (FTIR, Tensor). 27), PerkinElmer, USA; X-ray powder diffractometer (XRD, PW3040 / 60), Panaco, Netherlands.

[0041] Unless otherwise specified, the raw materials used in this invention can be obtained through ordinary commercial channels; the experimental conditions of this invention can be carried out under conventional experimental conditions.

[0042] Coating Preparation: The modified hexagonal boron nitride / epoxy resin scale inhibitor coating of the present invention is prepared by the following steps:

[0043] Substrate pretreatment: A 6061 aluminum plate with dimensions of 80mm×80mm×1mm was cut into 20mm×80mm×1mm pieces using a utility knife. Then, it was successively polished with 800-grit, 1000-grit, 1200-grit, and 2000-grit sandpaper to remove the surface oxide film. Finally, the polished aluminum plate was ultrasonically cleaned in anhydrous ethanol solution for 10 minutes to remove dirt and grease adhering to the surface.

[0044] Preparation of modified nanofillers

[0045] Preparation of modified nano-SiO2: 0.2 g nano-SiO2, 4 g KH550, and 100 g anhydrous ethanol were added to a beaker and ultrasonically dispersed for 3 h in a multi-functional ultrasonic cleaner at a temperature of 40 °C and a frequency of 60 Hz. 8 g of ultrapure water was added to the above system, and the mixture was heated and stirred at 80 °C for 4 h. The resulting mixture was centrifuged and then vacuum filtered. The filtered product was dried in a vacuum drying oven at 80 °C for 24 h to obtain modified nano-SiO2.

[0046] Preparation of modified h-BN: 0.8 g h-BN and 200 g ultrapure water were added to a beaker and ultrasonically dispersed for 0.5 h at a temperature of 40 °C and a frequency of 60 Hz to obtain a relatively homogeneous suspension. Then, 0.2 g dopamine (DA) and 0.24 g Tris were added to the above solution and the mixture was continuously stirred for 24 h (stirring speed of 500 r / min), during which the solution gradually changed from white to grayish-black. Finally, the reacted solution was vacuum filtered, and the product was washed five times with ultrapure water. After filtration, the product was dried in a vacuum drying oven at 80 °C for 24 h to obtain modified h-BN.

[0047] Coating preparation

[0048] Preparation of SiO2 / EP coating: 2g EP, 10g ethyl acetate, and 0.05g modified nano-SiO2 were added to a beaker and ultrasonically dispersed in a multi-functional ultrasonic cleaner for 0.5h at a temperature of 40℃ and a frequency of 60Hz. 1g polyamide resin was added to the above system, and ultrasonic dispersion was continued for 10min. The dispersed solution was poured into a spray gun and sprayed onto the pretreated aluminum plate surface. The spraying temperature was room temperature, the spraying pressure was 0.6MPa, and the spraying time was 10min. The sprayed sample was cured in a 150℃ electric thermostatic drying oven for 1h, then removed and cooled to room temperature to obtain the SiO2 / EP coating.

[0049] Preparation of modified h-BN / EP coating: 2g EP, 10g ethyl acetate, and 0.05g modified h-BN were added to a beaker and ultrasonically dispersed for 0.5h at 40℃ and 60Hz. 1g polyamide resin was added, and the mixture was ultrasonically dispersed for another 10min before spraying onto a pretreated aluminum plate surface. The sprayed sample was cured at 150℃ for 1h, then removed and cooled to room temperature to obtain the modified h-BN / EP coating.

[0050] Preparation of modified h-BN / SiO2 / EP coating: 2g EP, 10g ethyl acetate, 0.05g modified nano-SiO2, and 0.05g modified h-BN were added to a beaker and ultrasonically dispersed for 0.5h at 40℃ and 60Hz. After adding 1g polyamide resin, ultrasonic dispersion was continued for another 0.5h. The mixture was then sprayed onto the surface of a pretreated aluminum plate. The sample was cured at 150℃ for 1h, then removed and cooled to room temperature to obtain the modified h-BN / SiO2 / EP coating, which is the modified hexagonal boron nitride / epoxy resin scale inhibitor coating.

[0051] Performance testing and characterization

[0052] Coating scale inhibition performance test: The scale inhibition performance of the coating was tested using the static scaling method. A supersaturated CaCO3 solution was obtained by reacting NaHCO3 (5.04 g / L) and Ca(NO3)2·4H2O (7.10 g / L). By measuring the weight change of the coating samples after soaking for a certain period of time, the amount of scale on the coating surface was calculated, and the scaling rate of different coatings was compared to evaluate the scale inhibition performance of the coating.

[0053] Sample detection and characterization: FTIR was used to characterize the changes in chemical functional groups before and after modification with nano-SiO2 and h-BN, and the composition and structure of the coating were analyzed; SEM was used to observe the microstructure of the coating, including surface roughness, particle size, and morphology; EDS was used to determine the elemental composition of the coating, thereby understanding the chemical properties and compositional distribution of the coating; FTIR, SEM, EDS, and XRD were used to comprehensively analyze the functional groups, surface morphology, elemental composition, and crystal structure of the coating after scaling.

[0054] This invention successfully prepared a modified hexagonal boron nitride / epoxy resin scale inhibitor coating (modified h-BN / SiO2 / EP coating) using surface modification technology, and systematically studied its scale inhibitory performance. The synergistic effect of modified h-BN and nano-SiO2 significantly improved the scale inhibitory performance of the epoxy coating. The modified hexagonal boron nitride / epoxy resin scale inhibitor coating exhibits high hydrophobicity, with a water contact angle reaching 135.4°, significantly higher than that of pure epoxy coatings and single-filler modified coatings. This physical barrier effectively reduces water molecules and Ca2+. 2+ CO3 2-Plasma contact inhibited the nucleation and growth of CaCO3 crystals. Simultaneously, the introduction of modified h-BN and nano-SiO2 lowered the free energy of the coating surface, reducing the adsorption and growth of CaCO3 crystals on the coating surface. In particular, the chemical inertness and low surface energy of modified h-BN further enhanced the scale inhibition performance of the coating. Furthermore, the microstructure of the modified hexagonal boron nitride / epoxy resin scale inhibitor coating significantly influenced the growth direction of CaCO3 crystals, inducing the formation of thermodynamically unstable CaCO3 crystal forms (such as aragonite and aragonite). These unstable CaCO3 crystal forms have high solubility in water and are less likely to form dense scale layers, thus further improving the scale inhibition performance of the coating. Moreover, the synergistic effect of modified h-BN and nano-SiO2 significantly improved the scale inhibition performance of the coating. Compared with pure epoxy coatings and single-filler modified coatings, the scale formation of the modified hexagonal boron nitride / epoxy resin scale inhibitor coating was reduced by 48.2% and 34.7%, respectively, demonstrating excellent scale inhibition effects. In summary, the modified hexagonal boron nitride / epoxy resin scale-inhibiting coating significantly suppressed the formation and accumulation of CaCO3 crystals through multiple mechanisms, including physical barrier, chemical inhibition, and microstructure regulation, exhibiting excellent scale-inhibiting performance. This research provides new ideas and methods for developing highly efficient scale-inhibiting coatings, and has significant theoretical and practical application value. Future research can further optimize the composition and structure of the coating and explore its scale-inhibiting performance in more complex environments to promote its widespread application in industrial fields.

[0055] Example 1 Preparation of SiO2 / EP coating, modified h-BN / EP coating and modified h-BN / SiO2 / EP coating

[0056] The preparation of SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating includes the following steps:

[0057] S1. Substrate Pretreatment: Cut the 80mm×80mm×1mm 6061 aluminum plate into 20mm×80mm×1mm pieces using a utility knife. Then, sand the aluminum plate in the same direction to obtain a certain surface roughness. Finally, immerse the sanded aluminum plate in anhydrous ethanol solution for ultrasonic cleaning for 10 minutes to remove dirt and grease adhering to the surface of the aluminum plate.

[0058] S2. Preparation of modified nanofillers, including the following steps:

[0059] a. Preparation of modified nano-SiO2: 0.2g nano-SiO2, 4g KH550, and 100g anhydrous ethanol were added to a beaker and ultrasonically dispersed for 3 hours in a multi-functional ultrasonic cleaner at a temperature of 40℃ and a frequency of 60Hz. 8g ultrapure water was added to the above system, and the mixture was heated and stirred at 80℃ for 4 hours. The resulting mixture was centrifuged and then vacuum filtered. The filtered product was dried in a vacuum drying oven at 80℃ for 24 hours to obtain modified nano-SiO2. Figure 1 a).

[0060] b. Preparation of modified h-BN: 0.8 g h-BN and 200 g ultrapure water were added to a beaker and ultrasonically dispersed for 0.5 h at a temperature of 40 °C and a frequency of 60 Hz to obtain a relatively uniform suspension. Then, 0.2 g DA and 0.24 g Tris were added to the suspension and the mixture was continuously stirred for 24 h (stirring speed of 500 r / min), during which the solution gradually changed from white to grayish-black. Finally, the reacted solution was vacuum filtered, and the product was washed multiple times with ultrapure water. After filtration, the product was dried in a vacuum drying oven at 80 °C for 24 h to obtain modified h-BN ( Figure 1 b).

[0061] S3. The preparation of the three coatings is as follows:

[0062] Preparation of SiO2 / EP coating: 2g EP, 10g ethyl acetate, and 0.05g modified nano-SiO2 were added to a beaker and ultrasonically dispersed in a multi-functional ultrasonic cleaner for 0.5h at a temperature of 40℃ and a frequency of 60Hz. 1g polyamide resin was added to the above system, and ultrasonic dispersion was continued for 10min. The dispersed solution was poured into a spray gun and sprayed onto the surface of a pretreated aluminum plate. The sprayed sample was cured in a 150℃ electric thermostatic drying oven for 1h, then removed and cooled to room temperature to obtain the SiO2 / EP coating.

[0063] Preparation of modified h-BN / EP coating: 2g EP, 10g ethyl acetate and 0.05g modified h-BN were added to a beaker and ultrasonically dispersed for 0.5h at a temperature of 40℃ and a frequency of 60Hz. 1g polyamide resin was added and ultrasonically dispersed for another 10min before spraying onto the surface of a pretreated aluminum plate. The sprayed sample was cured in a 150℃ electric thermostatic drying oven for 1h and then cooled to room temperature to obtain the modified h-BN / EP coating.

[0064] Preparation of modified h-BN / SiO2 / EP coating: 2g EP, 10g ethyl acetate, 0.05g modified nano-SiO2, and 0.05g modified h-BN were added to a beaker and ultrasonically dispersed for 0.5h at 40℃ and 60Hz. After adding 1g polyamide resin, ultrasonic dispersion was continued for another 0.5h, followed by spraying onto the surface of a pretreated aluminum plate. The sprayed sample was cured in a 150℃ electric thermostatic drying oven for 1h, then removed and cooled to room temperature to obtain the modified h-BN / SiO2 / EP coating. Figure 1 c).

[0065] Infrared spectroscopy analysis was performed on the nano-SiO2 before and after modification in Example 1, such as... Figure 2 As shown. For nano-SiO2, 3430 cm⁻¹ -1 The relatively broad characteristic peak in the vicinity belongs to the -OH characteristic peak of the nano-SiO2 surface, 1632 cm⁻¹. -1 The characteristic peak is caused by the bending vibration of the -OH group in water. (1100 cm⁻¹) -1 The strong and broad characteristic peak is due to the Si-O-Si antisymmetric stretching vibration. (1397 cm⁻¹) -1 809cm -1 and 469cm -1 This is attributed to Si-O bond vibrations. Compared to the infrared spectrum of unmodified nano-SiO2, the infrared spectrum of modified nano-SiO2 after KH550 modification showed four new characteristic peaks (2942 cm⁻¹). -1 1564cm -1 1482cm -1 and 691cm -1 ), of which 2942cm -1 The prominent peak in the vicinity is attributed to the -CH2 asymmetric stretching vibration in the silane coupling agent KH550. (1564 cm⁻¹) -1 The characteristic peak originates from the variable-angle vibration of NH2 in the KH550 molecule. (1482 cm⁻¹) -1 The weaker peak is due to the -CH3 asymmetric stretching vibration. 691 cm⁻¹ -1 The characteristic peaks belong to the in-plane rocking vibration of -CH2. New characteristic peaks, such as -CH3, -CH2, and NH2, appeared in the infrared spectrum of the modified nano-SiO2. The appearance of these characteristic peaks indicates that KH550 has undergone a chemical reaction with the nano-SiO2 surface, forming chemical bonds, and that KH550 has been successfully grafted onto the nano-SiO2 surface. This chemical bonding not only improves the hydrophobicity of nano-SiO2 but also enhances its dispersibility and stability in the polymer matrix.

[0066] To confirm the modification of h-BN, infrared spectral analysis was performed on h-BN before and after modification, such as... Figure 3 As shown. 3425cm-1 The relatively broad characteristic peak at 1395 cm⁻¹ corresponds to the bending vibration of the -OH group in water molecules. -1 The characteristic peak is relatively broad and 813 cm. -1 The sharper characteristic peaks at 1395 cm⁻¹ correspond to the in-plane stretching vibration and out-of-plane bending vibration of BN, respectively. Compared with the infrared spectrum of the original h-BN, the h-BN modified with dopamine shows a higher characteristic peak at 1395 cm⁻¹. -1 The intensity of the characteristic peaks increased significantly, confirming that PDA successfully modified h-BN.

[0067] Furthermore, infrared spectral analysis was performed on the SiO2 / EP coating, the modified h-BN / EP coating, and the modified h-BN / SiO2 / EP coating, such as... Figure 4 As shown. Infrared spectral analysis of the SiO2 / EP coating shows that at 3430 cm⁻¹... -1 Corresponding to the characteristic peak of -OH; 2942 cm⁻¹ -1 The -CH2 asymmetric vibration in KH550; 1740 cm -1 It is the characteristic peak of C=O in epoxy resin molecules; 1620 cm⁻¹ -1 and 1512cm -1 All are characteristic peaks of the benzene ring in epoxy resin molecules; 1235 cm⁻¹ -1 and 1034cm -1 This corresponds to the stretching vibration peak of COC in the epoxy ring; additionally, at 1100 cm⁻¹... -1 and 809cm -1 These are the characteristic peaks of Si-O-Si and Si-O in nano-SiO2, respectively, indicating that silane-modified nano-SiO2 has been successfully added to the coating. Compared with the SiO2 / EP coating, the modified h-BN / EP coating did not show the characteristic peaks of nano-SiO2 in its infrared spectrum, but at 1440 cm⁻¹, it did show the characteristic peaks of nano-SiO2. -1 BN characteristic peaks appeared. For the infrared spectrum of the modified h-BN / SiO2 / EP coating, specifically at 1440 cm⁻¹... -1 and 1397cm -1 BN characteristic peaks appeared nearby, and then at 1100 cm⁻¹ -1 and 809cm -1 Characteristic peaks of nano-SiO2 were observed nearby. These findings confirm that both modified nano-SiO2 and modified h-BN have been successfully added to the coating.

[0068] The microstructure of the coating was analyzed using SEM, and the water contact angle (WCA) of the coating was measured using a contact angle meter to analyze its wetting properties. Specific results are as follows: Figure 5 As shown, the SiO2 / EP coating surface is generally smooth, but noticeable pitted structures appear in localized areas. Figure 5 a). This phenomenon is most likely caused by the uneven distribution of nano-SiO2 particles in the coating. The WCA of the SiO2 / EP coating was measured to be 109.6°. The modified h-BN / EP coating surface exhibited a noticeable rough structure. Figure 5 b) is attributed to the dispersing effect of modified h-BN in EP. Notably, the WCA of the modified h-BN / EP coating is higher than that of the SiO2 / EP coating, reaching 118.7°. For the modified h-BN / SiO2 / EP coating ( Figure 5 c) The coating surface is less smooth and has more rough structures than the previous two. This is because during the coating preparation process, the modified nano-SiO2 and modified h-BN interact with EP, resulting in a more rough structure on the coating surface. This structural change is likely to affect the wetting properties of the coating. Compared to the SiO2 / EP coating and the modified h-BN / EP coating, the WCA of the modified h-BN / SiO2 / EP coating is significantly improved, reaching 135.4°.

[0069] The elemental composition of different coating surfaces was analyzed using EDS, such as... Figure 6 As shown. The SiO2 / EP coating surface contains four elements: C (66.03%), O (31.55%), F (1.22%), and Si (1.19%). Figure 6 a); where F element belongs to KH550, and Si element belongs to nano SiO2 and KH550; combined with the infrared spectral analysis of nano SiO2 before and after modification ( Figure 1 It was deduced that the modified nano-SiO2 was successfully added to the SiO2 / EP coating. In the modified h-BN / EP coating surface elements, B (11.67%) originated from h-BN, while N (12.41%) originated from h-BN and dopamine (…). Figure 6 b). Compared with the surface elemental analysis of the modified h-BN / EP coating, the modified h-BN / SiO2 / EP coating, in addition to B, C, N, and O, also contains F (1.25%) and Si (1.26%). Figure 6 c). Combined with coating infrared spectroscopy analysis ( Figure 4 As can be seen, both modified h-BN and nano-SiO2 have been successfully added to the coating.

[0070] Example 2 Scale inhibition performance test of the coating prepared in Example 1

[0071] The scale inhibition performance of the coating was tested using a static scaling method. A supersaturated CaCO3 solution was obtained by reacting NaHCO3 (5.04 g / L) and Ca(NO3)2·4H2O (7.10 g / L) (Formula (2-1)). The scale amount on the coating surface was calculated by measuring the weight change of the coating sample after soaking for a certain period of time, and the scaling rate of different coatings was compared to evaluate the scale inhibition performance of the coating.

[0072] Ca(NO3)2·4H2O+2NaHCO3→CaCO3↓+2NaNO3+5H2O+CO2↑ (2-1)

[0073] like Figure 7 As shown, with increasing immersion time, the scale buildup on the surfaces of the SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating showed an increasing trend, and then gradually stabilized. When the coatings were immersed in supersaturated CaCO3 solution for 360 h, the scale buildup on the surfaces of the SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating reached 2.641 mg / cm³. 2 2.095 mg / cm 2 and 1.368 mg / cm 2 Among the samples, the SiO2 / EP coating exhibited the highest scale buildup, while the modified h-BN / SiO2 / EP coating showed the lowest. Compared to the SiO2 / EP coating and the modified h-BN / EP coating, the scale inhibition rate of the modified h-BN / SiO2 / EP coating increased by 48.2% and 34.7%, respectively. This indicates that the addition of modified h-BN and modified nano-SiO2 can effectively improve the scale inhibition performance of epoxy coatings.

[0074] The morphological characteristics of CaCO3 crystals on different coating surfaces were compared and analyzed using SEM. The results are as follows: Figure 8 As shown. After immersion in a supersaturated CaCO3 solution for 48 hours, the CaCO3 crystals on the SiO2 / EP coating surface are cubic and prismatic, with relatively uniform size, and the crystals are closely packed together, forming a multi-layered, tightly packed structure with almost no gaps. Figure 8 (a1, 8a2). This morphology indicates that the SiO2 / EP coating has a weak inhibitory effect on the nucleation and growth of CaCO3 crystals, allowing CaCO3 crystals to nucleate and grow relatively easily. However, the CaCO3 crystal distribution on the surface of the modified h-BN / EP coating is sparse, with obvious gaps between the crystals. Figure 8The results (b1, 8b2) indicate that the coating significantly inhibits the growth of CaCO3 crystals, hindering their nucleation and growth to some extent. Compared with the SiO2 / EP coating and the modified h-BN / EP coating, the CaCO3 crystals on the surface of the modified h-BN / SiO2 / EP coating are sparsely distributed, and the number and packing density of crystals are significantly lower than the former two coatings. Figure 8 c1), and in some areas, CaCO3 crystals form a multilayered structure with an irregular shape. Figure 8 c2). This indicates that the modified h-BN / SiO2 / EP coating has a more significant inhibitory effect on CaCO3 crystal growth, effectively limiting the nucleation and growth of CaCO3 crystals.

[0075] Infrared spectroscopy analysis of coating samples before and after scaling can identify the specific composition and structural changes of the scaling material. For example... Figure 9 As shown, compared with the infrared spectrum of the coating before scaling ( Figure 4 After immersion in a supersaturated CaCO3 solution for 48 hours, the infrared spectra of the SiO2 / EP coating, modified h-BN / EP coating, and modified h-BN / SiO2 / EP coating showed significant changes, with the appearance of characteristic absorption peaks belonging to CaCO3. Among them, the peak at 2518 cm⁻¹... -1 and 1727cm -1 The nearby absorption peak corresponds to the C=O stretching vibration in CaCO3. (1432 cm⁻¹) -1 864cm -1 and 700cm -1 These represent the antisymmetric stretching vibration, in-plane bending vibration, and out-of-plane vibration of CO in CaCO3, respectively.

[0076] Furthermore, XRD analysis was performed on the surface of the coating after scaling. Figure 10The diffraction peaks at 2θ = 64.6° and 78.1° are those of the aluminum plate. After immersion in a supersaturated CaCO3 solution for 48 hours, CaCO3 diffraction peaks appeared on the surfaces of the SiO2 / EP coating, the modified h-BN / EP coating, and the modified h-BN / SiO2 / EP coating. Among them, 2θ = 29.3°, 35.7°, 46.9°, 56.9°, and 60.7° are diffraction peaks of calcite; 2θ = 22.4°, 37.9°, and 48.2° are diffraction peaks of aragonite; and 2θ = 38.9° and 42.8° are diffraction peaks of aragonite. It is worth mentioning that the CaCO3 crystal form on the SiO2 / EP coating surface is only calcite, while the modified h-BN / EP coating and the modified h-BN / SiO2 / EP coating surfaces have three CaCO3 crystal forms (calcite, aragonite, and aragonite). Furthermore, the intensity of the diffraction peak (2θ = 29.3°) of calcite on the surface of the modified h-BN / SiO2 / EP coating is significantly lower than that of the SiO2 / EP coating and the modified h-BN / EP coating; and the intensity of the diffraction peaks of aragonite and spherulite on the surface of the modified h-BN / SiO2 / EP coating is also significantly lower than that of the modified h-BN / EP coating. This is combined with the trend of scaling on the coating surface (…). Figure 7 It can be seen that, on the one hand, the addition of modified h-BN induces the formation of thermodynamically unstable CaCO3 crystal forms (aragonite and aragonite) on the coating surface; on the other hand, the synergistic effect between epoxy resin, modified nano-SiO2 and modified h-BN effectively enhances the scale inhibition performance of the modified h-BN / SiO2 / EP coating.

[0077] The prepared modified h-BN / SiO2 / EP coating had a significant impact on CaCO3 crystal formation and exhibited excellent scale inhibition performance. The reasons can be summarized in the following three aspects:

[0078] First, the modified h-BN / SiO2 / EP coating exhibits excellent physical barrier properties. The SiO2 / EP coating surface is smooth, but noticeable pitted structures appear in localized areas, resulting in a water contact angle of only 19.6°. Figure 5 a). Compared with the SiO2 / EP coating, the modified h-BN / EP coating has a significantly rougher surface structure, and its water contact angle is also significantly increased to 118.7°. Figure 5 b). However, the modified h-BN / SiO2 / EP coating is rougher than both the SiO2 / EP coating and the modified h-BN / EP coating, and its water contact angle is further increased to 135.4°. Figure 5 c). This significant increase in roughness and improved hydrophobicity enables the modified h-BN / SiO2 / EP coating to effectively block water molecules and Ca. 2+ CO3 2- Plasma contact effectively inhibits the nucleation and growth of CaCO3 crystals.

[0079] Secondly, the chemical properties of the modified h-BN / SiO2 / EP coating surface inhibit the formation of CaCO3 crystals. For the SiO2 / EP coating, its smooth surface provides relatively ideal nucleation sites for CaCO3 crystals. On this relatively flat surface, Ca... 2+ and CO3 2- Ions can easily aggregate and arrange themselves according to certain lattice rules, thereby promoting the nucleation and growth of CaCO3 crystals. Figure 11 a). Compared with the SiO2 / EP coating, the modified h-BN / EP coating has a significantly sparser distribution of CaCO3 crystals on its surface due to the addition of modified h-BN. Figure 8 (b1, 8b2). This stems from the chemical inertness and low surface energy of h-BN itself. After modification, more hydrophobic groups are introduced onto its surface, further reducing the free energy of the coating surface. This low surface energy characteristic makes it difficult for CaCO3 crystals to adsorb and grow on the coating surface, thus significantly reducing CaCO3 deposition. Figure 11 b). Compared with modified h-BN / EP coating ( Figure 11 (b) After simultaneously adding modified h-BN and modified nano-SiO2 to the coating, the chemical properties of the modified h-BN / SiO2 / EP coating surface are further optimized, exhibiting a stronger ability to suppress the formation of CaCO3 crystals. Figure 8 (c1, 8c2). The introduction of modified nano-SiO2 not only increases the surface roughness of the coating, but also further enhances the hydrophobic properties of the coating surface through the synergistic effect of its surface active groups and modified h-BN. Figure 5 c). This synergistic effect makes Ca 2+ and CO3 2- The adsorption capacity of ions on the surface of the modified h-BN / SiO2 / EP coating is significantly weakened, thereby effectively inhibiting the nucleation and growth of CaCO3 crystals. Figure 11 c).

[0080] Finally, the microstructure of the modified h-BN / SiO2 / EP coating significantly influenced the growth direction of CaCO3 crystals. On the surface of the SiO2 / EP coating, CaCO3 crystals tended to grow along specific crystal planes, forming a more regular crystal structure. Figure 11 a), and the crystal exhibits a multilayer close-packed structure ( Figure 8 a1, 8a2). Compared with the SiO2 / EP coating, the packing density of CaCO3 crystals on the surface of the modified h-BN / EP coating is significantly reduced ( Figure 8 b1, 8b2). This is because the unique crystal structure and surface properties of h-BN can serve as heterogeneous nucleation sites for the growth of CaCO3 crystals (b1, 8b2). Figure 11 b). It can induce the formation of thermodynamically unstable CaCO3 crystals, such as aragonite and spherulite, on the coating surface. These unstable CaCO3 crystals have relatively high solubility in water and poor stability, making it difficult for them to form large-scale, densely packed scale layers on the coating surface. Under certain conditions, they may redissolve back into the solution, thereby effectively reducing scale accumulation and playing a scale inhibition role. However, on the surface of the modified h-BN / SiO2 / EP coating, the growth direction of CaCO3 crystals is disturbed and inhibited, the crystal morphology becomes irregular, and the crystal distribution is more sparse. Figure 11 c). This is mainly due to the synergistic effect of modified h-BN and modified nano-SiO2, which increases the hydrophobicity of the modified h-BN / SiO2 / EP coating, creating more physical barriers for the growth of CaCO3 crystals. When CaCO3 crystals grow near the modified h-BN and modified nano-SiO2, the synergistic effect between them creates a steric hindrance effect on crystal growth, restricting and interfering with it. The growth of CaCO3 crystals is affected by the modified h-BN and modified nano-SiO2, preventing them from continuing to accumulate smoothly in their original direction. This forces them to change their growth path, resulting in irregular crystal growth. Furthermore, it is difficult to form a continuous, dense scale layer on the surface of the modified h-BN / SiO2 / EP coating; instead, the scale exists in a dispersed and irregular form, greatly reducing the impact of the scale layer on the coating performance and effectively improving the coating's scale inhibition ability.

[0081] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a modified hexagonal boron nitride / epoxy resin scale inhibitor coating, characterized in that, Includes the following steps: S1. Substrate pretreatment: After the aluminum plate is polished to a rough surface, it is ultrasonically cleaned in anhydrous ethanol. S2. Preparation of modified nanofillers, including the following steps: a. Preparation of modified nano-SiO2: 0.1~0.5g nano-SiO2, 2~7g KH550 and 100g anhydrous ethanol were mixed and ultrasonically dispersed at 30~50℃ and 40~60kHz for 3h. Then 8g ultrapure water was added and heated and magnetically stirred at 80℃ for 4h. After heating and stirring, the mixture was centrifuged, vacuum filtered and then vacuum dried to obtain modified nano-SiO2. b. Preparation of modified h-BN: 0.3~1.0g h-BN and 200g ultrapure water were mixed and ultrasonically dispersed at a temperature of 30~50℃ and a frequency of 40~60kHz for 0.5h. Then, 0.1~0.5g dopamine and 0.1~0.3g Tris were added and magnetically stirred for 24h. After magnetic stirring, the mixture was vacuum filtered, washed, and then vacuum dried to obtain modified h-BN. S3. Preparation of modified h-BN / SiO2 / EP coating: 2g epoxy resin, 10g ethyl acetate, 0.01~0.1g modified nano-SiO2 and 0.01~0.1g modified h-BN are mixed and ultrasonically dispersed at a temperature of 30~50℃ and a frequency of 40~60kHz for 0.5h. Then 1g polyamide resin is added and ultrasonically dispersed for 0.5h. The mixture is then sprayed onto the surface of a pretreated aluminum plate, cured, and cooled to room temperature to obtain the modified h-BN / SiO2 / EP coating.

2. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, The ultrasonic cleaning time in step S1 is 10 minutes.

3. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, The rotation speed of the magnetic stirring in step a is 100 rpm, and the rotation speed of the magnetic stirring in step b is 100 rpm.

4. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, In step S2, the centrifugation speed is 1000 rpm and the time is 5 min; the vacuum filtration time is 0.5 min; and the vacuum drying time is 24 h at a temperature of 80℃.

5. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, The spraying conditions in step S3 are: spraying at room temperature and 0.6 MPa; and the curing conditions are: temperature of 150°C and time of 60 min.

6. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, Step b involves washing with ultrapure water, repeated 5 times.

7. The method for preparing the modified hexagonal boron nitride / epoxy resin scale inhibitor coating according to claim 1, characterized in that, The aluminum plate in step S1 has dimensions of 20 mm × 80 mm × 1 mm.

8. A modified hexagonal boron nitride / epoxy resin scale inhibitor coating prepared by any one of the preparation methods described in claims 1 to 7.

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