Laser-etched sharkskin structure superhydrophobic marine protective coating and method thereof

Abstract

The present application relates to the technical field of marine engineering materials, and discloses a sharkskin structure super-hydrophobic marine protective coating based on laser etching and a method thereof.The coating takes foamed copper as a substrate, constructs a sharkskin biomimetic microcavity array through laser etching, and sequentially loads a silane-modified epoxy amine layer, a silane-quaternary ammonium chitosan composite modified candle soot nanoparticle layer.The present application further introduces a self-repairing microcapsule composite modification system, a substrate interface plasma grafting-oxidation transition layer synergistic strengthening technology and a broad-spectrum anti-biofouling composite system, discards fluorine-containing compounds, utilizes waste, has super-hydrophobic, corrosion-resistant, impact-resistant, oil-water separation and anti-biofouling multifunction, and is outstanding in mechanical stability and environmental protection, and is suitable for marine equipment protection such as ships, offshore wind power and the like.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering materials technology, specifically relating to a superhydrophobic marine protective coating based on laser etching of a sharkskin structure and its method. Background Technology

[0002] Marine engineering equipment, such as ships, offshore wind turbines, and seawater desalination facilities, are exposed to harsh environments characterized by high salinity, high humidity, strong impacts, and biofouling, facing severe challenges of corrosion and fouling. Superhydrophobic coating technology, due to its potential in corrosion prevention, self-cleaning, and oil-water separation, is considered one of the effective ways to solve these problems.

[0003] However, existing superhydrophobic coating technologies still have significant drawbacks: First, most rely on fluorinated compounds to obtain low surface energy, which decompose to produce per- and polyfluoroalkyl substances with environmental persistence and biotoxicity, posing a serious threat to marine ecosystems. Second, the mechanical stability of the coatings is generally insufficient; designs based on single-scale micro / nano rough structures are prone to wear or detachment under dynamic wave loads and impacts, resulting in short service life. Third, the interfacial adhesion between the coating and the substrate is insufficient, making it prone to peeling under long-term wave impacts and vibrations. In addition, the coatings lack self-healing capabilities, leading to protective failure after localized damage. Furthermore, existing antifouling technologies are insufficient in protecting against stubborn organisms such as barnacles and mussels. Finally, existing coatings are functionally limited, typically focusing only on one aspect of superhydrophobicity or corrosion resistance, making it difficult to meet the multifunctional integrated requirements of the marine environment for synergistic protection against corrosion, impact, biofouling, and oil-water separation.

[0004] Therefore, developing a marine protective coating that is environmentally friendly, mechanically durable, cost-effective, and multifunctional has become a pressing technical challenge in this field. Summary of the Invention

[0005] This invention aims to overcome the aforementioned deficiencies of the prior art and provides a superhydrophobic marine protective coating based on laser etching of a sharkskin structure and its method. Specifically, this invention addresses the following technical problems:

[0006] 1. Solve the environmental toxicity problem of traditional fluorinated superhydrophobic coatings;

[0007] 2. Solve the problem of poor mechanical stability and easy breakage and detachment of single-scale micro / nano structures;

[0008] 3. Solve the problem of insufficient adhesion between the coating and the substrate, which makes it easy to peel off under wave impact;

[0009] 4. Solves the problem of protective failure and lack of self-repair capability after localized damage to the coating;

[0010] 5. To address the shortcomings of existing antifouling technologies in protecting against stubborn organisms such as barnacles and mussels;

[0011] 6. To resolve the contradiction that existing coatings have only one function and cannot meet the multiple protection needs of the marine environment in a coordinated manner;

[0012] 7. Reduce raw material costs and preparation complexity, and provide an efficient, environmentally friendly and scalable preparation solution.

[0013] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0014] This invention provides a superhydrophobic marine protective coating based on laser etching of a sharkskin structure, comprising:

[0015] Copper foam substrate;

[0016] A sharkskin-inspired microcavity array formed by laser etching on the copper foam substrate;

[0017] A silane-modified epoxy amine layer is disposed on the shark skin biomimetic microcavity array. The silane-modified epoxy amine layer is formed by reacting KH550 silane coupling agent, bisphenol A diglycidyl ether and polyamide curing agent in ethanol.

[0018] A silane-quaternized chitosan composite modified candle soot nanoparticle layer is disposed on the silane-modified epoxyamine layer.

[0019] Furthermore, the sharkskin biomimetic microcavity array has microcavities of 20-50 μm and a depth of 15±2 μm.

[0020] Furthermore, the pore size of the copper foam substrate is 200±30μm.

[0021] Furthermore, the candle soot nanoparticles have a particle size of 100-500 nm and are obtained by collecting the soot from burning paraffin candles and grinding them through a 200-mesh sieve.

[0022] Furthermore, the quaternized chitosan has a molecular weight of 5000-10000 Da and a degree of quaternization substitution ≥80%.

[0023] Furthermore, in the silane-quaternized chitosan composite modified candle soot nanoparticle layer, the loading of quaternized chitosan is 1-3%.

[0024] Furthermore, urea-formaldehyde resin microcapsules are uniformly dispersed in the silane-quaternized chitosan composite modified candle soot nanoparticle layer. The particle size of the urea-formaldehyde resin microcapsules is 5-10 μm, and the loading is 5-8% of the total coating mass. The core of the urea-formaldehyde resin microcapsules encapsulates a repair agent in which the mass ratio of silane-modified epoxy resin prepolymer to KH570 silane coupling agent is 1:0.3, and the wall material of the urea-formaldehyde resin microcapsules is modified with polydopamine.

[0025] Furthermore, a plasma grafting-oxidation transition layer is provided between the foamed copper substrate and the silane-modified epoxyamine layer. The plasma grafting-oxidation transition layer is formed by mixed plasma grafting and electrochemical oxidation treatment, with a thickness of 50-100 nm and a porous Cu2O structure.

[0026] Furthermore, in the silane-quaternized chitosan composite modified candle soot nanoparticle layer, the quaternized chitosan is a quaternized chitosan-sodium alginate graft copolymer with a grafting rate of 40-50%, and 0.5-1wt% of eugenol / menthol composite microcapsules are added to the nanoparticle suspension. The eugenol / menthol composite microcapsules have a particle size of 1-3μm, a wall material of polylactic acid-glycolic acid copolymer, and a release period of ≥180 days.

[0027] This invention also provides a method for preparing the aforementioned laser-etched sharkskin-structured superhydrophobic marine protective coating, comprising the following steps:

[0028] (1) Pretreatment of copper foam substrate: ultrasonically cleaned with anhydrous ethanol and 1 mol / L dilute hydrochloric acid for 15 min, rinsed with deionized water until neutral, and vacuum dried at 60℃ for 2 h.

[0029] (2) Laser etching: A sharkskin-inspired microcavity array was formed on a copper foam substrate by etching using a fiber laser processing system. The laser wavelength was 1030nm, the average power was 30W, and the scanning speed was 300mm / s.

[0030] (3) Interface strengthening treatment: The laser-etched foamed copper substrate is grafted with mixed plasma using argon-argon mixed plasma (volume ratio 1:3, power 150W, treatment time 8-10min). Then, a Cu2O transition layer is formed in 0.1mol / L NaOH solution using a constant potential method (voltage 0.8V, time 15min).

[0031] (4) Preparation of silane-quaternized chitosan composite modified candle soot nanoparticle suspension: disperse candle soot nanoparticles in anhydrous ethanol, add KH570 silane coupling agent, stir at 50℃ and 400rpm for 20min, then sonicate for 30min, then add quaternized chitosan accounting for 1-3% of the mass of candle soot nanoparticles, and stir at 30℃ and 300rpm for 60min;

[0032] (5) Preparation of silane-modified epoxy amine solution: Bisphenol A diglycidyl ether, polyamide curing agent and KH550 silane coupling agent were stirred in anhydrous ethanol at 25°C for 12 h;

[0033] (6) Coating construction: After the interface strengthening treatment, the foamed copper substrate is cleaned by hydrogen plasma, and then dipped in the silane-modified epoxy amine solution obtained in step (5) and the suspension obtained in step (4) in sequence, and then cured at 60°C for 2 hours and 80°C for 1 hour.

[0034] Furthermore, in step (2), the laser etching spot diameter is 25 μm, the Z-axis resolution is 1 μm, and argon gas is introduced at a rate of 15 L / min for protection.

[0035] Furthermore, in step (3), the amount of KH570 added is 200 μL per 0.5 g of candle soot nanoparticles.

[0036] Furthermore, in step (5), the removal speed of both the dip-coated silane-modified epoxyamine solution and the suspension is 2 mm / s.

[0037] Compared with the prior art, the advantages of this invention are as follows:

[0038] (1) Environmental friendliness and economy: Completely eliminate fluorine-containing compounds and avoid PFAS pollution from the source; the core nanomaterials are derived from waste candle ash, realizing waste resource utilization and low cost; introduce biodegradable quaternized chitosan, which is non-toxic and harmless and meets the requirements of green and sustainable development.

[0039] (2) Excellent mechanical stability and durability: Through the cross-scale hierarchical structure design of “micron-level sharkskin microcavity + nano-level CSNs protrusion”, and combined with the formation of a strong Si-O-Cu / Si-O-Si covalent network at the interface by the dual silane coupling agent, the bonding force between the coating and the substrate is greatly enhanced, enabling it to withstand the harsh mechanical tests such as high-pressure water jets and wave impacts.

[0040] (3) Self-repair function: By introducing urea-formaldehyde resin microcapsules, a repair agent is released when the coating is damaged, so as to achieve self-repair of the interface with crack width ≤50μm. After repair, the water contact angle is ≥155°, the corrosion inhibition efficiency is maintained at more than 95%, and the service life is increased from the original 3 years to more than 5 years.

[0041] (4) Enhanced interface bonding: Through the synergistic enhancement of plasma grafting-oxidation transition layer, the interface adhesion is increased from 3MPa to more than 5.2MPa. It does not peel off after 1000 repeated bending. In addition, the Cu2O transition layer has antibacterial and anti-corrosion properties, forming a three-level protection system.

[0042] (5) Broad-spectrum antifouling: Through quaternized chitosan-sodium alginate graft copolymer and natural repellent microcapsules, a triple antifouling mechanism (antibacterial, anti-attachment, and repellent) is achieved, reducing the attachment rate of barnacle larvae to 1.2%, reducing the attachment amount of mussels by 98%, and maintaining an antibacterial rate of over 96%.

[0043] (6) Multifunctional synergistic integration: Through the synergy of physical structure and chemical modification, this invention integrates five functions in a single environmentally friendly coating for the first time: superhydrophobicity, excellent corrosion resistance, efficient oil-water separation, significant drag reduction and long-term anti-biofouling. This solves the problem of single function in existing technologies and achieves comprehensive protection for marine equipment.

[0044] (7) The process is simple and easy to scale up: The “laser etching + dip coating” process is simple, with high processing efficiency (scanning speed up to 300mm / s) and uniform coating coverage (coverage rate ≥97.6%), which is very suitable for the large-scale preparation and application of marine engineering large equipment surfaces. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0046] Figure 1 A flowchart illustrating the preparation method of a superhydrophobic marine protective coating based on laser etching for a sharkskin structure provided by this invention;

[0047] Figure 2 SEM image of the superhydrophobic marine protective coating based on laser etching shark skin structure provided by the present invention at 500x magnification;

[0048] Figure 3 SEM image of the superhydrophobic marine protective coating based on laser etching shark skin structure provided by the present invention at 2000x magnification;

[0049] Figure 4 A comparison chart of the contact angle (CA) stability of the multifunctional superhydrophobic coating provided in the embodiments of the present invention under different pH environments;

[0050] Figure 5 A comparison chart showing the correlation between oil-water separation efficiency and contact angle (CA) performance of the superhydrophobic coating provided in the embodiments of the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0053] This invention provides a superhydrophobic marine protective coating based on laser etching of a sharkskin structure, comprising:

[0054] Copper foam substrate;

[0055] A sharkskin-inspired microcavity array formed by laser etching on the copper foam substrate;

[0056] A silane-modified epoxy amine layer is disposed on the shark skin biomimetic microcavity array. The silane-modified epoxy amine layer is formed by reacting KH550 silane coupling agent, bisphenol A diglycidyl ether and polyamide curing agent in ethanol.

[0057] A silane-quaternized chitosan composite modified candle soot nanoparticle layer is disposed on the silane-modified epoxyamine layer.

[0058] The sharkskin-inspired microcavity array consists of microcavities of 20-50 μm in size and a depth of 15 ± 2 μm.

[0059] The pore size of the copper foam substrate is 200±30μm.

[0060] The nanoparticles of the candle soot have a particle size of 100-500 nm and are obtained by collecting the soot from burning paraffin candles and grinding them through a 200-mesh sieve.

[0061] The quaternized chitosan has a molecular weight of 5000-10000 Da and a degree of quaternization substitution ≥80%.

[0062] In the silane-quaternized chitosan composite modified candle soot nanoparticle layer, the loading of quaternized chitosan is 1-3%.

[0063] The silane-quaternized chitosan composite modified candle soot nanoparticle layer contains uniformly dispersed urea-formaldehyde resin microcapsules with a particle size of 5-10 μm and a loading of 5-8% of the total coating mass. The core of the urea-formaldehyde resin microcapsules encapsulates a repair agent consisting of a silane-modified epoxy resin prepolymer and a KH570 silane coupling agent in a mass ratio of 1:0.3, and the wall material of the urea-formaldehyde resin microcapsules is modified with polydopamine.

[0064] A plasma grafting-oxidation transition layer is provided between the foamed copper substrate and the silane-modified epoxyamine layer. The plasma grafting-oxidation transition layer is formed by mixed plasma grafting and electrochemical oxidation treatment, with a thickness of 50-100 nm and a porous Cu2O structure.

[0065] In the silane-quaternized chitosan composite modified candle soot nanoparticle layer, the quaternized chitosan is a quaternized chitosan-sodium alginate graft copolymer with a grafting rate of 40-50%, and 0.5-1wt% of eugenol / menthol composite microcapsules are added to the nanoparticle suspension. The eugenol / menthol composite microcapsules have a particle size of 1-3μm, the wall material is polylactic acid-glycolic acid copolymer, and the release period is ≥180 days.

[0066] Please see Figure 1 As shown, the present invention also provides a method for preparing the aforementioned laser-etched sharkskin-structured superhydrophobic marine protective coating, comprising the following steps:

[0067] Step S1, Pretreatment of copper foam substrate: Ultrasonic cleaning with anhydrous ethanol and 1 mol / L dilute hydrochloric acid for 15 min, rinsing with deionized water until neutral, and vacuum drying at 60℃ for 2 h;

[0068] Step S2, Laser Etching: A sharkskin-inspired microcavity array is formed on a copper foam substrate by etching using a fiber laser processing system, wherein the laser wavelength is 1030nm, the average power is 30W, and the scanning speed is 300mm / s.

[0069] Step S3, prepare silane-quaternized chitosan composite modified candle soot nanoparticle suspension: disperse candle soot nanoparticles in anhydrous ethanol, add KH570 silane coupling agent, stir at 50℃ and 400rpm for 20min, then sonicate for 30min, then add quaternized chitosan accounting for 1-3% of the mass of candle soot nanoparticles, and stir at 30℃ and 300rpm for 60min;

[0070] Step S4, prepare silane-modified epoxyamine solution: stir bisphenol A diglycidyl ether, polyamide curing agent and KH550 silane coupling agent in anhydrous ethanol at 25°C for 12 h;

[0071] Step S5, Coating Construction: After the laser-etched copper foam substrate is cleaned by argon plasma, it is sequentially dipped into the silane-modified epoxyamine solution obtained in step S4 and the suspension obtained in step S3, and then cured at 60°C for 2 hours and 80°C for 1 hour.

[0072] In step S2, the laser etching spot diameter is 25 μm, the Z-axis resolution is 1 μm, and argon gas is introduced at a rate of 15 L / min for protection.

[0073] In step S3, the amount of KH570 added is 200 μL per 0.5 g of candle soot nanoparticles.

[0074] In step S5, the removal speed of both the dip-coated silane-modified epoxyamine solution and the suspension is 2 mm / s.

[0075] The following detailed description of the laser-etched sharkskin-structured superhydrophobic marine protective coating and its preparation method provided by the present invention, using specific embodiments and comparative examples, provides a detailed explanation.

[0076] Example 1: Basic Coating Preparation and Performance Testing

[0077] (1) Raw materials and equipment

[0078] Copper foam: pore size 200μm, purity 99.9%;

[0079] Fiber laser processing system: Model YL-30, wavelength 1030nm, average power 30W;

[0080] Paraffin candles: Commercially available products used to collect candle ash (CSNs);

[0081] Silane coupling agents: KH570, KH550, analytical grade;

[0082] Epoxy resin: Bisphenol A diglycidyl ether, analytical grade;

[0083] Curing agent: low molecular weight polyamide, analytical grade;

[0084] Quaternized chitosan (QCS): molecular weight 8000 Da, degree of quaternization substitution 85%, analytical grade;

[0085] Urea-formaldehyde resin microcapsules: particle size 5-10μm, loading amount calculated based on total coating mass;

[0086] Quaternized chitosan-sodium alginate graft copolymer: grafting rate 45%;

[0087] Eugenol / menthol composite microcapsules: particle size 1-3μm, wall material is polylactic acid-glycolic acid copolymer;

[0088] Electrochemical oxidation equipment: potentiostat, NaOH solution.

[0089] (2) Preparation process

[0090] a. Pretreatment of copper foam substrate: The copper foam was ultrasonically cleaned in anhydrous ethanol and 1 mol / L dilute hydrochloric acid for 15 minutes each, rinsed repeatedly with deionized water until neutral, and dried in a vacuum drying oven at 60℃ for 2 hours for later use.

[0091] b. Laser etching to fabricate a sharkskin-inspired microcavity array: Pretreated copper foam was fixed on a laser processing platform. A fiber laser system (wavelength 1030nm, average power 30W, pulse frequency 50kHz, pulse width 100ns) was used. The beam polarization direction was adjusted by a half-wave plate and a polarizer, and focused to a spot diameter of 25μm by a 5x beam expander. The scanning speed was set to 300mm / s, the Z-axis resolution to 1μm, and etching was performed under an atmosphere of 15L / min argon protection to form a sharkskin-inspired microcavity array with a size of 20-50μm and a depth of approximately 15μm on the surface of the copper foam.

[0092] c. Interface strengthening treatment: The laser-etched copper foam substrate was placed in a plasma treatment chamber and an argon-argon mixed gas (volume ratio 1:3) was introduced and treated at 150W power for 9 min. Then it was immersed in 0.1mol / L NaOH solution and a constant voltage of 0.8V was applied for 15 min to form a porous Cu2O transition layer with a thickness of about 80nm.

[0093] d. Preparation of CSNs and Silane-QCS Composite Modification: Soot from the combustion of paraffin candles was collected by flame deposition, then mechanically ground for 1 hour using a soft brush and passed through a 200-mesh sieve to obtain CSNs with a particle size of 100-500 nm. 0.5 g of CSNs was weighed and dispersed in 20 mL of anhydrous ethanol, and 200 μL of KH570 was added. The mixture was magnetically stirred at 50 °C and 400 rpm for 20 minutes, followed by ultrasonic treatment (frequency 40 kHz, power 150 W) for 30 minutes. Subsequently, 1.8% QCS by mass of CSNs was added to the suspension, along with 6% urea-formaldehyde resin microcapsules by mass of the coating (based on the total mass of the copper foam substrate, silane-modified epoxy amine layer, and nanoparticle layer). The mixture was stirred for 60 minutes at 30°C and 300 rpm to fix QCS onto the CSNs surface through hydrogen bonding and ring-opening reaction with residual epoxy groups of KH570, resulting in a silane-QCS composite modified CSNs ethanol suspension with a concentration of 25 mg / mL.

[0094] e. Preparation of KH550 modified epoxy amine (KH-BP): Dissolve 2g of bisphenol A diglycidyl ether and 1g of polyamide curing agent in 20mL of anhydrous ethanol, stir until completely dissolved, add 140μL of KH550, and stir continuously at 25℃ for 12 hours to form a cross-linked KH-BP solution.

[0095] f. Construction of the hierarchical superhydrophobic coating: The interface-strengthened copper foam was placed in a plasma cleaner and cleaned with argon plasma at 100W for 5 minutes to activate the surface. Then, it was first immersed in a KH-BP solution for 30 seconds and then uniformly pulled out at a speed of 2 mm / s; next, it was immersed in a silane-QCS composite modified CSNs suspension for 60 seconds and similarly uniformly pulled out at a speed of 2 mm / s. Finally, the sample was placed in an oven and cured at 60℃ for 2 hours, followed by curing at 80℃ for 1 hour, yielding the final QCS-KH-CSNs-CF superhydrophobic marine protective coating based on a laser-etched sharkskin structure. The coating thickness is approximately 8-10 μm.

[0096] (3) Performance test results

[0097] The coating prepared in this case was subjected to comprehensive performance testing, and the results are as follows:

[0098] Superhydrophobic properties: The water contact angle (CA) is as high as 164.8°, and the sliding angle (SA) is 4.5°. After immersion in solutions at pH=2 and pH=12 for 9 hours, the CA remains at 152.1° and 152.4°, respectively, demonstrating excellent chemical stability.

[0099] Corrosion resistance: In a 3.5 wt% NaCl solution, the corrosion current density of this coating was measured to be as low as 1.91 × 10⁻⁶ by electrochemical testing.－4 With an A / cm² resistance, the corrosion inhibition efficiency reaches 97.2% compared to unprotected foamed copper; the charge transfer resistance (Rct) is increased to 615.3 Ω·cm. 2 .

[0100] Mechanical stability: After being subjected to 2 hours of 1MPa high-pressure water jet impact, simulated 12 hours of wave load cycle and 100 drop impacts, the coating's CA still remained at 150.9°, 151.5° and 150.6° respectively, with the structure intact and no obvious damage.

[0101] Oil-water separation and drag reduction performance: For light oil / water mixtures, the separation efficiency reaches 98.1%, and the efficiency is still higher than 97% after 10 cycles. The speed of a miniature ship model coated with this coating increased from 16.8 cm / s to 22.1 cm / s, with a significant drag reduction effect and a speed increase of 32.3%.

[0102] Antifouling performance: The antibacterial rates against Escherichia coli and Vibrio vulnificus reached 96.2% and 95.7%, respectively. In a 30-day coating experiment in a real marine environment, the amount of Chlorella attached to the coating surface was reduced by 90.5% compared to the unmodified coating, and the attachment rate of oyster larvae was only 4.8%.

[0103] Self-healing performance: When the coating develops cracks with a width ≤50μm, the microcapsules rupture and release the repair agent, completing the repair within 12-24 hours. After repair, the water contact angle is ≥155°, and the corrosion inhibition efficiency is over 95%.

[0104] Interface adhesion: The coating adhesion reaches 5.2MPa (pull-off test), and there is no peeling after 1000 repeated bending cycles (bending radius 5mm).

[0105] Broad-spectrum antifouling: reduced barnacle larvae attachment rate to 1.2%, mussel attachment to 98%, and no significant stubborn biological attachment during 30-day sea trials.

[0106] Combined Figure 2 and Figure 3 Scanning electron microscope images show that the coating surface prepared by the method of this invention successfully constructed a regular shark skin biomimetic microcavity array with a size of 20-50 μm, and the surface and walls of the microcavities were uniformly covered with protrusions of candle soot nanoparticles with a particle size of 100-500 nm, forming an ideal micro / nano cross-scale hierarchical structure. This is the structural basis for the coating to obtain excellent superhydrophobicity and mechanical stability.

[0107] See also Figure 4As shown in the figure, the contact angle changes of the coating of the present invention (labeled "KH-CSNs") and several existing typical superhydrophobic coatings (including CBD_5Fe@polyamide, composite silica sol, PDMS / EP / STA / TiO2, etc.) in acidic to alkaline solutions with pH values ​​ranging from 2 to 12 are compared. The results show that the coating of the present invention can maintain excellent superhydrophobic properties even in extreme pH environments, with CA consistently above 152°, demonstrating significantly better chemical stability and durability than existing technologies.

[0108] See you again at the end. Figure 5 As shown in the figure, the relationship between the CA value and oil-water separation efficiency of various existing superhydrophobic coatings (such as diatomaceous earth / SiO2 / PDMS, ZnO / PDMS, PDMS@COF@MS, etc.) is illustrated in scatter plots, and compared with the coating of the present invention (labeled "this method"). It can be seen that the coating of the present invention achieves an oil-water separation efficiency of up to 98.1% while maintaining an extremely high contact angle (approximately 164°), demonstrating significantly superior overall performance compared to existing technologies and exhibiting excellent synergistic functional characteristics.

[0109] Example 2: Parameter Adjustment Example

[0110] The difference between Example 2 and Example 1 is that the key process parameters have been adjusted to demonstrate the adaptability of this technical solution:

[0111] Microcapsule loading: The loading of urea-formaldehyde resin microcapsules was adjusted to 7% of the total coating mass;

[0112] Plasma treatment time: Adjust the mixed plasma treatment time to 10 min;

[0113] Grafting rate of the graft copolymer: The grafting rate of the quaternized chitosan-sodium alginate graft copolymer was adjusted to 50%;

[0114] QCS addition amount: The QCS addition amount was adjusted to 3% of the CSNs mass. The resulting coating maintained excellent superhydrophobic properties (CA>163°) and the antibacterial rate against Vibrio vulnificus was improved to 96.5%.

[0115] Laser scanning speed: The laser scanning speed was adjusted to 250 mm / s. At this speed, the microcavity depth increased slightly (approximately 18 μm), the mechanical locking effect of the coating was enhanced, and the CA retention rate was higher after water jet testing.

[0116] Copper foam specifications: A similar hierarchical structure was successfully constructed using a copper foam substrate with a pore size of 170μm, proving that the present invention has good universality for substrates of different specifications.

[0117] Comparison with Example 1: No QCS modification

[0118] The difference between this comparative example and Example 1 is that QCS is not added in step c of the preparation process; only a silane-modified CSNs suspension is prepared. Performance test results show that although the coating possesses superhydrophobicity (CA=162.5°) and certain corrosion resistance, its inhibition rate against Escherichia coli and Vibrio vulnificus is less than 30%. During the 30-day sea trial, algae adhesion was severe, and the coating completely lost its antifouling function.

[0119] Comparison with Example 2: Laser-free microcavity structure

[0120] The difference between this comparative example and Example 1 is that step b of the preparation process, laser etching, is omitted, and the same nanolayer is directly constructed on the smooth copper foam surface. Test results show that the initial CA of the coating is 152°, but after 2 hours of water jet impact, the CA drops significantly to below 142°, and local peeling of the nanolayer occurs, proving that the mechanical interlocking effect of the micron-scale sharkskin structure is lacking, and the mechanical durability of the coating is significantly deteriorated.

[0121] In summary, the core of this invention lies in achieving multifunctional integration of a single coating through multi-level synergy of "physical structure design, chemical interface modification, bioactivity introduction, and self-healing function." Specifically:

[0122] Self-repair mechanism: When the coating is damaged, the microcapsules release a repair agent, which repairs the interface through a cross-linking reaction and extends the service life.

[0123] Interface enhancement mechanism: Plasma grafting increases active groups, and electrochemical oxidation forms a Cu2O transition layer, achieving mechanical interlocking and chemical bonding.

[0124] Broad-spectrum antifouling mechanism: Quaternary ammonium cationic antibacterial, sodium alginate reducing adhesion, and natural repellent repelling larvae, providing triple protection.

[0125] Stable Superhydrophobic Structure Across Scales: Micron-sized sharkskin-inspired microcavities, constructed on a copper foam surface via laser etching, together with nanoscale candle soot particles protruding through dip-coating, form a robust, multi-scale hierarchical rough structure. This structure effectively traps air, reducing the liquid-solid contact area to below 8.7%, stably maintaining the Cassie-Baxter superhydrophobic state, thereby achieving a water contact angle as high as 164.8° and a sliding angle of less than 5°.

[0126] Dual-silane coupling enhances interfacial bonding: KH570 modified nanoparticles are used, along with KH550 modified epoxy amine as an intermediate binder layer. The synergistic effect of these two materials forms a robust Si-O-Cu and Si-O-Si covalent bond network within the coating and at the substrate interface, significantly enhancing the coating's mechanical stability and adhesion, enabling it to withstand high-pressure water jets and wave impacts.

[0127] Physicochemical synergistic antifouling: Environmentally friendly quaternized chitosan is firmly fixed to the surface of the nanolayer through chemical bonding. Its quaternary ammonium cations can effectively disrupt microbial cell membranes, providing active chemical bactericidal / bacteriostatic capabilities; at the same time, the superhydrophobic surface greatly reduces the available attachment sites for microorganisms, providing passive physical anti-adhesion capabilities. The synergy of these two factors achieves a high antibacterial rate of >95% and an adhesion reduction rate of over 90% against marine bacteria and algae, solving the problem of the single function of traditional coatings.

[0128] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0129] Furthermore, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0130] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A superhydrophobic marine protective coating based on a sharkskin structure obtained by laser etching, characterized in that, include: Copper foam substrate; A sharkskin-inspired microcavity array formed by laser etching on the copper foam substrate; A silane-modified epoxy amine layer is disposed on a shark skin-inspired bionic microcavity array. The silane-modified epoxy amine layer is formed by reacting KH550 silane coupling agent, bisphenol A diglycidyl ether, and polyamide curing agent in ethanol. A plasma grafting-oxidation transition layer is disposed between the foamed copper substrate and the silane-modified epoxy amine layer. The plasma grafting-oxidation transition layer is formed by mixed plasma grafting and electrochemical oxidation treatment, with a thickness of 50-100 nm and a porous Cu2O structure. A silane-quaternized chitosan composite modified candle soot nanoparticle layer is disposed on the silane-modified epoxyamine layer; in the silane-quaternized chitosan composite modified candle soot nanoparticle layer, the loading of quaternized chitosan is 1-3%, the quaternized chitosan is a quaternized chitosan-sodium alginate graft copolymer with a grafting rate of 40-50%, and 0.5-1wt% of eugenol / menthol composite microcapsules are added to the nanoparticle suspension, the particle size of the eugenol / menthol composite microcapsules being 1- The wall material is polylactic acid-glycolic acid copolymer with a release period of ≥180 days. Urea-formaldehyde resin microcapsules are uniformly dispersed in the silane-quaternized chitosan composite modified candle soot nanoparticle layer. The particle size of the urea-formaldehyde resin microcapsules is 5-10 μm, and the loading is 5-8% of the total mass of the coating. The core of the urea-formaldehyde resin microcapsules is wrapped with a repair agent in which the mass ratio of silane-modified epoxy resin prepolymer to KH570 silane coupling agent is 1:0.

3. The wall material of the urea-formaldehyde resin microcapsules is modified with polydopamine.

2. The superhydrophobic marine protective coating based on laser etching of sharkskin structure according to claim 1, characterized in that, The sharkskin-inspired microcavity array consists of microcavities of 20-50 μm in size and a depth of 15 ± 2 μm.

3. The superhydrophobic marine protective coating based on laser etching of sharkskin structure according to claim 1, characterized in that, The pore size of the copper foam substrate is 200±30μm.

4. The superhydrophobic marine protective coating based on laser etching of sharkskin structure according to claim 1, characterized in that, The nanoparticles of candle soot have a particle size of 100-500 nm and are obtained by collecting them from burning paraffin candles and grinding them through a 200-mesh sieve.

5. The superhydrophobic marine protective coating based on laser etching of sharkskin structure according to claim 1, characterized in that, The molecular weight of quaternized chitosan is 5000-10000 Da, and the degree of quaternization substitution is ≥80%.

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