A mussel-inspired reinforced nanocellulose composite antifouling coating and a preparation method thereof
The nano-cellulose composite coating, designed using mussel biomimicry, solves the problems of insufficient adhesion and poor anti-swelling performance of nano-cellulose-based antifouling coatings, achieving a highly efficient and environmentally friendly antifouling effect, and is suitable for marine engineering components.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN UNIV
- Filing Date
- 2026-04-08
- Publication Date
- 2026-05-29
AI Technical Summary
Existing nanocellulose-based antifouling coatings suffer from problems such as insufficient adhesion, poor anti-swelling performance, limited antifouling mechanisms, and difficulty in synergistically optimizing processes and performance.
Using a mussel-inspired design, a composite coating consisting of zwitterionic cellulose nanofibers (ZCNF), hydroxyl-terminated polydimethylsiloxane (PDMS), and silanized modified Si-PDA@Ag NPs is constructed. This coating utilizes the adhesive properties of polydopamine, the hydrophobicity of PDMS, and the bactericidal properties of Ag NPs to create a mechanism that enhances adhesion, regulates swelling, and synergistically prevents fouling.
Significantly improves coating adhesion, provides excellent anti-swelling properties and highly effective antifouling, improves coating adhesion level by 3-4 levels, has a thickness change rate of ≤5%, and a fouling biofilm coverage rate of ≤10%, meeting environmental protection requirements and suitable for marine engineering applications.
Smart Images
Figure CN122103973A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of marine antifouling materials technology, specifically to a mussel-inspired enhanced nanocellulose composite antifouling coating and its preparation method. Background Technology
[0002] Marine biofouling is a long-standing core challenge in the field of marine engineering. Caused by the attachment, growth, and reproduction of fouling organisms such as bacteria, algae, and barnacles on underwater substrate surfaces, it not only significantly increases ship drag and fuel consumption but also accelerates the corrosion process of offshore platforms, oil pipelines, and other structures, shortening their service life and causing huge economic losses. Traditional antifouling technologies mostly rely on coatings containing copper, zinc, and organometallic compounds, releasing biocides to achieve antifouling. However, these coatings are highly ecotoxic, disrupting the marine food chain and ecosystem, and have been gradually restricted or banned by environmental regulations in various countries. Against this backdrop, nanocellulose (CNF), with its advantages of being renewable, biodegradable, and highly biocompatible, has become a research hotspot for antifouling coating substrates. Its surface is rich in hydroxyl groups, and through chemical modification, it can be used to construct superhydrophilic, superhydrophobic, or amphiphilic surfaces, forming differentiated antifouling mechanisms. Currently, three types of nanocellulose-based antifouling coatings—superhydrophobic, superhydrophilic, and amphiphilic—have been developed.
[0003] However, all three existing types of nanocellulose-based antifouling coatings have significant drawbacks: superhydrophobic coatings suffer from poor mechanical stability and insufficient substrate adhesion, making them prone to detachment under seawater scouring and friction conditions; superhydrophilic coatings are susceptible to osmotic pressure-driven swelling in high-salt seawater, leading to structural damage and a sharp decline in antifouling durability; and amphiphilic coatings suffer from poor component compatibility and complex preparation processes, hindering large-scale application. In summary, current nanocellulose-based antifouling coatings generally suffer from core defects such as weak substrate adhesion, poor anti-swelling performance in high-salt environments, a single antifouling mechanism lacking active bactericidal function, and difficulty in synergistically optimizing processes and performance. Therefore, developing nanocellulose-based composite antifouling coatings that combine high adhesion, excellent anti-swelling properties, synergistic and efficient antifouling functions, and controllable processes has become a critical technical problem urgently needing to be solved in the field of marine antifouling materials. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of existing nanocellulose-based antifouling coatings, such as insufficient adhesion, poor anti-swelling performance, single antifouling mechanism, and difficulty in balancing process and performance. This invention provides a mussel-inspired enhanced nanocellulose composite antifouling coating and its preparation method. Through multi-component synergistic design, this coating achieves integrated adhesion enhancement, anti-swelling regulation, and synergistic antifouling, offering advantages such as environmental sustainability, excellent performance, and controllable process, thus meeting the practical application needs of the marine engineering field.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: I. A method for preparing zwitterionic cellulose nanofibers (ZCNF) Includes the following steps: 1. Disperse cellulose nanofibers (CNF) in deionized water and sonicate for 30 minutes at a power of 300W and a frequency of 20kHz to form a CNF dispersion with a mass fraction of 0.2%; wherein the cellulose nanofibers have a length of 100-500nm, a diameter of 5-20nm, a hydroxyl content of ≥8mmol / g, and a purity of ≥98%.
[0006] 2. Mix the CNF dispersion with morpholine ethanesulfonic acid (MES), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) in a mass ratio of 1:1:1.5:1, stir for 2 hours to ensure full activation of the carboxyl groups, add lysine, and stir for 8-12 hours; wherein the mass ratio of cellulose nanofibers to lysine is 1:1.
[0007] 3. After the reaction is complete, the product is dialyzed for two days, and the ZCNF dispersion is collected. The zeta potential of the ZCNF is -5 to +5 mV to ensure zwitterionic balance.
[0008] II. A method for preparing silanized modified PDA@Ag NPs Includes the following steps: 1. Take 2 mL of ammonia water (28-30%), add 40 mL of ethanol and 90 mL of deionized water, and stir gently for 1.5 hours. Dissolve 0.5 g of dopamine hydrochloride in 10 mL of water, and add the solution dropwise. Stir at room temperature for 24 hours to form a uniform dispersion of PDA nanoparticles. Then centrifuge at 12000 r / min, wash three times alternately with anhydrous ethanol and deionized water, and vacuum dry. Dilute with deionized water to 10 mg / mL and store at 4 ℃. The purity of dopamine hydrochloride is ≥98% (chemically pure), and the particle size of PDA nanoparticles is 100-200 nm.
[0009] 2. Dissolve silver nitrate in deionized water to obtain a silver nitrate solution; add ammonia (28-30% by mass) dropwise until the solution becomes clear again. Slowly add the solution dropwise to the above PDA nanoparticle dispersion at a rate of 1 mL / min, and stir at room temperature in the dark for 1 hour to allow the Ag to settle. + The silver nitrate is reduced to Ag NPs on the PDA surface to form PDA@Ag NPs; the purity of the silver nitrate is ≥99.8% (analytical grade).
[0010] 3. The above dispersion was centrifuged at 12,000 r / min for 10 minutes; the precipitate was collected and washed three times alternately with anhydrous ethanol and deionized water, and then dried under vacuum at 60°C for 1 hour.
[0011] 4. Disperse the dried PDA@Ag NPs in ethylene glycol, add silane coupling agent KH580 (γ-mercaptopropyltriethoxysilane), and sonicate the mixture for 30 minutes at a power of 240W and a frequency of 40kHz. After the reaction, a silanized modified Si-PDA@Ag NPs dispersion is obtained. The ethylene glycol has a purity of ≥99.5% (analytical grade), the silane coupling agent KH580 has a purity of ≥97%, and the mass ratio of PDA@Ag NPs to KH580 is 1:2.
[0012] 5. After the reaction was completed, centrifugation was performed at a speed of 12000 r / min for 15 minutes. The precipitate was collected, washed twice with anhydrous ethanol, and then dried under vacuum at 60℃ for 1 hour to obtain silanized modified Si-PDA@Ag NPs. The surface grafting rate of the Si-PDA@Ag NPs was ≥10%, and the characteristic peaks of Si-OC could be confirmed by FTIR characterization.
[0013] III. A Mussel-Inspired Enhanced Nanocellulose Composite Antifouling Coating The coating is composed of zwitterionic cellulose nanofibers (ZCNF), hydroxyl-terminated polydimethylsiloxane (PDMS), and silanized modified Si-PDA@Ag NPs in a mass ratio of (80-120):(20-50):(5-15); the dry film thickness of the coating is 80-150 μm. The hydroxyl-terminated polydimethylsiloxane has a number-average molecular weight of 5000-10000 and a hydroxyl content ≥0.5%.
[0014] IV. Preparation method of the above-mentioned mussel biomimetic enhanced nanocellulose composite antifouling coating Includes the following steps: 1. Disperse zwitterionic cellulose nanofibers (ZCNF) in deionized water and ultrasonically disperse for 40 minutes at a power of 400W and a frequency of 20kHz to form a uniform ZCNF dispersion. 2. Add hydroxyl-terminated polydimethylsiloxane (PDMS) and Si-PDA@Ag NPs to the above ZCNF dispersion, continue ultrasonic dispersion for 30 minutes, and then stir at room temperature for 2 hours to form a stable composite coating precursor solution; wherein, the mass ratio of ZCNF, PDMS and Si-PDA@Ag NPs is (80-120):(20-50):(5-15); 3. The composite coating precursor liquid is applied to the pretreated substrate surface using a spraying method; the spraying pressure is 0.3 MPa, the nozzle distance from the substrate surface is 15 cm, the spraying rate is 5 mL / min, and the wet film thickness of the coating is controlled between 150-300 μm; the substrate is a commonly used substrate in marine engineering, including Q235 steel, epoxy resin coating or polyvinyl chloride, and the substrate surface is pretreated by sandblasting, degreasing and drying. 4. After coating, place the substrate in a forced-air drying oven, preheat at 40℃ for 1 hour, then heat to 80℃ for 3 hours to cure, and then cool naturally to room temperature to obtain a mussel biomimetic enhanced nanocellulose composite antifouling coating.
[0015] V. Application of the above-mentioned mussel-inspired enhanced nanocellulose composite antifouling coating in antifouling of marine engineering components The marine engineering components include ships, offshore platforms, oil pipelines, or fishing nets.
[0016] The technical principle of this invention is as follows: 1. Adhesion enhancement mechanism: Polydopamine (PDA) mimics the adhesive properties of byssal silks of marine mussels. The catechol groups in its molecular structure can form multiple interactions with the substrate surface, such as covalent bonds and hydrogen bonds. At the same time, the amino and hydroxyl groups on the PDA surface can form a stable interfacial bond with nanocellulose (CNF), thereby significantly improving the adhesion between the coating and the substrate.
[0017] 2. Anti-swelling regulation mechanism: Hydroxyl-terminated polydimethylsiloxane (PDMS) has excellent hydrophobicity and chemical stability. By using silanized modified Si-PDA@Ag NPs as a "bridge", PDMS and zwitterionic cellulose nanofibers (ZCNF) are chemically combined to construct a hydrophobic-hydrophilic interwoven network structure, which effectively inhibits coating swelling caused by seawater penetration.
[0018] 3. Synergistic antifouling mechanism: The zwitterionic structure of ZCNF can form a strong hydration layer on the coating surface, which hinders the initial adhesion of fouling organisms; the low surface energy of PDMS can promote the desorption of already attached fouling organisms; Ag NPs have broad-spectrum bactericidal properties and can actively kill bacteria, algae and other microorganisms. The three work together to achieve multiple antifouling effects of "anti-adhesion-easy desorption-strong bactericidal".
[0019] VI. Beneficial Effects The mussel-inspired bio-enhanced nanocellulose composite antifouling coating and its preparation method provided by this invention have the following significant advantages: 1. Significantly improved adhesion: Through the biomimetic adhesion design of polydopamine to mussels, the coating achieves an adhesion level of 0-1 with commonly used marine engineering substrates such as Q235 steel and epoxy resin, which is 3-4 levels higher than that of unmodified nanocellulose coatings. It can withstand harsh service conditions such as seawater erosion and mechanical friction.
[0020] 2. Excellent anti-swelling performance: The chemical cross-linking of PDMS and ZCNF constructs a stable hydrophobic-hydrophilic network structure. After immersion in artificial seawater for 30 days, the coating thickness change rate is ≤5%, which is far superior to the existing nanocellulose-based coatings (thickness change rate ≥20%), ensuring the structural integrity of the coating in the long-term marine environment.
[0021] 3. Synergistic and efficient antifouling mechanism: It integrates the synergistic antifouling functions of the hydration layer physical barrier, low surface energy desorption and Ag NPs active sterilization. The coverage of fouling organisms in the real sea cladding is ≤10% after 60 days, which is better than the existing single-mechanism antifouling coatings (fouling coverage ≥30%), and has a stable protective effect against diverse fouling organisms.
[0022] 4. Environmentally friendly and sustainable: The coating uses renewable nanocellulose as the base material, releases no heavy metal biocides, and is biodegradable, so it will not pollute the marine ecological environment and meets marine environmental protection requirements.
[0023] 5. Strong process controllability: The reaction conditions in each step are mild (reaction temperature is room temperature - 100℃), and the raw materials are readily available; the coating method is sprayed, which is convenient for large-scale production and is suitable for the surface treatment of complex-shaped marine engineering components, with broad industrial application prospects. Attached Figure Description
[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0025] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.
[0026] Figure 1 This is a schematic diagram of the preparation process of the composite antifouling coating in an embodiment of the present invention; Figure 2 Here are SEM images of the composite antifouling coating in this embodiment of the invention (a is the surface morphology, b is the cross-sectional structure). Figure 3 The water contact angle test diagram of the coating in the embodiment of the present invention is shown (a is the control group, bd are the experimental groups with different ratios). Figure 4 The above image shows the antibacterial effect test results of the coating in this embodiment of the invention. The top image shows Escherichia coli (a is the control group, bf are experimental groups with different ratios); the bottom image shows Staphylococcus aureus (a is the control group, be are experimental groups with different ratios). Detailed Implementation
[0027] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. 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.
[0028] Example 1 A method for preparing a mussel-inspired enhanced nanocellulose composite antifouling coating includes the following steps: 1. Preparation of zwitterionic cellulose nanofibers (ZCNF): S1. Take 140 mg of cellulose nanofibers (length 100-500 nm, diameter 5-20 nm, hydroxyl content ≥8 mmol / g, purity ≥98%), disperse them in 70 mL of deionized water, and sonicate for 30 minutes (power 300 W, frequency 20 kHz) to form a CNF dispersion with a mass fraction of 0.2%. S2. Mix the above CNF dispersion with morpholine ethanesulfonic acid (MES), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) in a mass ratio of 1:1:1.5:1, stir for 2 hours to ensure full activation of the carboxyl groups, add 140 mg of lysine, stir for 8-12 hours, and dialyze for two days to obtain the product. 2. Preparation of silanized modified PDA@Ag NPs: S1. Take 2 mL of ammonia water (28-30%), add 40 mL of ethanol and 90 mL of deionized water, and stir gently for 1.5 hours; dissolve 0.5 g of dopamine hydrochloride in 10 mL of water, and add it dropwise to the above solution, stirring at room temperature for 24 hours to form a uniform PDA nanoparticle dispersion; then centrifuge at 12000 r / min, wash three times alternately with anhydrous ethanol and deionized water, and vacuum dry. Dilute with deionized water to 10 mg / mL, store at 4 ℃ to form a PDA nanoparticle dispersion with a particle size of 100-200 nm; S2. Dissolve 1 g of silver nitrate (purity ≥99.8%, analytical grade) in 40 mL of deionized water, and slowly add it dropwise to the above PDA dispersion (dropping rate 1 mL / min). Stir at room temperature in the dark for 1 hour to form a PDA@Ag NPs dispersion. S3. Centrifuge (12000 r / min, 15 min), wash the precipitate three times with anhydrous ethanol and deionized water alternately, then vacuum dry it, and then dilute it with ethylene glycol to 1 mg / mL. S4. Add 0.5 mL of ethylene glycol solution of PDA@Ag NPs to 1 mg of KH580 (purity ≥97%), and sonicate the mixture for 30 minutes at a power of 240 W and a frequency of 40 kHz. After the reaction, a silanized modified Si-PDA@Ag NPs dispersion is obtained. S5. Centrifuge (12000 r / min, 15 min), wash the precipitate twice with anhydrous ethanol, and vacuum dry at 60 °C for 6 h to obtain Si-PDA@Ag NPs. FTIR characterization confirmed the characteristic peaks of Si-OC, and the grafting rate was 12%.
[0029] 3. Preparation of composite antifouling coating: S1. Disperse 4.5 mg ZCNF in an appropriate amount of deionized water and sonicate for 15 minutes (power 400 W, frequency 20 kHz) to form a uniform ZCNF dispersion. S2. Add 4.5 mg of hydroxyl-terminated PDMS (number average molecular weight 5000–10000, hydroxyl content ≥0.5%) and 0.5 mg of Si-PDA@Ag NPs to the above dispersion, continue ultrasonic dispersion for 30 minutes, and stir at room temperature for 2 hours to form a composite coating precursor solution. S3. Apply the coating to the surface of the pretreated Q235 steel substrate by spraying. The spraying pressure is 0.3 MPa, the nozzle distance is 15 cm, the spraying rate is 5 mL / min, and the wet film thickness is 200 μm. S4. After coating, place in a forced-air drying oven, preheat at 40℃ for 1 hour, cure at 80℃ for 3 hours, and cool naturally to room temperature to obtain a composite anti-fouling coating with a dry film thickness of 100μm.
[0030] Example 2 The difference between this embodiment and Example 1 is that the mass ratio of ZCNF, PDMS and Si-PDA@Ag NPs is 80:20:5, while the specifications of other raw materials and preparation steps are the same as in Example 1, and a composite antifouling coating with a dry film thickness of 80μm is finally obtained.
[0031] Example 3 The difference between this embodiment and Example 1 is that the mass ratio of ZCNF, PDMS and Si-PDA@Ag NPs is 120:50:15, while the specifications of the other raw materials and the preparation steps are the same as in Example 1, and a composite antifouling coating with a dry film thickness of 150 μm is finally obtained.
[0032] Performance testing The composite antifouling coatings prepared in Examples 1-3 were characterized in structure and tested in performance. The test methods are as follows: 1. Structural characterization: FTIR (wavenumber range 4000-400cm) was used. -1 Characterize the changes in chemical bonds of each component; observe the surface morphology and cross-sectional structure of the coating using SEM (accelerating voltage 10kV); observe the particle size and dispersibility of PDA@Ag NPs using TEM (accelerating voltage 200kV); and analyze the elemental composition and chemical state of the coating surface using XPS (Al Kα rays).
[0033] 2. Mechanical and Adhesion Testing: The tensile strength of the coating was tested using a tensile testing machine (tensile rate 1 mm / min); the adhesion of the coating was tested using the cross-cut test (ASTM D3359-09).
[0034] 3. Anti-swelling performance test: Immerse the coating in artificial seawater (salinity 3.5%) and measure the coating thickness change rate periodically.
[0035] 4. Antifouling performance test: S1. Antibacterial test: The plate count method is used to test the antibacterial activity against Escherichia coli (E. coli). E. coli ) and Staphylococcus aureus ( S. aureus ) 24-hour sterilization rate; S2. Anti-algae test: Using Chlorella as the test object, the amount of algae cells attached to the coating surface was detected after soaking for 7 days. S3. Real-sea panel test: Panels are hung in coastal waters of my country for 60 days, and the biofouling coverage rate of the coating surface is statistically analyzed.
[0036] Test results show that the coatings prepared in Examples 1-3 all formed stable hydrophobic-hydrophilic interpenetrating network structures, with each component tightly bound and without obvious agglomeration; the coating adhesion level reached 0-1, the tensile strength was moderate, and the mechanical stability was excellent; after immersion in artificial seawater for 30 days, the coating thickness change rate was ≤5%, demonstrating outstanding anti-swelling performance; the 24-hour bactericidal rate against Escherichia coli and Staphylococcus aureus was ≥95%, showing significant anti-algae effect; and the surface fouling biofilm coverage rate of the actual sea-mounted board was ≤10% after 60 days, exhibiting excellent overall synergistic antifouling effect. Among them, Example 1 showed the best performance, and the comprehensive indicators met the requirements for long-term environmental protection and antifouling applications in marine engineering.
[0037] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A method for preparing a mussel-inspired enhanced nanocellulose composite antifouling coating, characterized in that, Includes the following steps: S1. Preparation of zwitterionic cellulose nanofiber (ZCNF) dispersion: Cellulose nanofiber (CNF) was dispersed in deionized water and ultrasonically dispersed for 30 minutes at an ultrasonic power of 300W and a frequency of 20kHz to obtain a CNF dispersion with a mass fraction of 0.2%. This CNF dispersion was then mixed with morpholinoethanesulfonic acid (MES), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) at a mass ratio of 1:1:1.5:
1. The mixture was stirred for 2 hours to ensure full activation of the carboxyl groups. Lysine was then added, and the reaction was stirred for 8-12 hours. The ZCNF dispersion was collected after two days of dialysis. S2. Preparation of silanized modified PDA@Ag NPs (Si-PDA@Ag NPs) dispersion: PDA NPs dispersion was prepared, and it was mixed with silver ammonia solution to obtain PDA@Ag NPs. KH580 was added at a mass ratio of 1:2, and the mixture was ultrasonically reacted for 30 minutes with an ultrasonic power of 240W and a frequency of 40kHz to obtain Si-PDA@Ag NPs dispersion. S3. Preparation of composite coating precursor solution: The ZCNF dispersion obtained in step S1 is ultrasonically dispersed for 30 minutes with an ultrasonic power of 400W and a frequency of 20kHz. Hydroxyl-terminated polydimethylsiloxane (PDMS) and the Si-PDA@Ag NPs ethylene glycol solution obtained in step S2 are added and stirred at 60°C for 2 hours to obtain a stable precursor solution. S4. Coating treatment: The composite coating precursor liquid is coated onto the surface of the pretreated substrate by spraying. The spraying pressure is controlled at 0.3MPa, the nozzle distance from the substrate is 15cm, the spraying rate is 5mL / min, and the wet film thickness is 150-300μm. S5. Gradient curing molding: After coating, preheat at 40℃ for 1 hour, then heat to 80℃ for 3 hours, and cool naturally to room temperature to obtain a mussel biomimetic enhanced nanocellulose composite antifouling coating.
2. The preparation method according to claim 1, characterized in that, The CNF in step S1 has a length of 100-500 nm, a diameter of 5-20 nm, a hydroxyl content of ≥8 mmol / g, a purity of ≥98%, and a mass ratio of CNF to lysine of 1:1; the prepared ZCNF has a zeta potential of -5 to +5 mV and retains the original crystal structure and morphological characteristics of CNF.
3. The preparation method according to claim 2, characterized in that, The CNF is high-purity nanocellulose prepared by sulfuric acid hydrolysis, TEMPO oxidation, or mechanical grinding. The CNF dispersion process uses an ice-water bath for temperature control to prevent ultrasonic overheating from causing fiber structure degradation.
4. The preparation method according to claim 1, characterized in that, In step S2, the loading reaction of PDA NPs with silver nitrate was carried out in the dark, and the centrifugation speed was controlled at 8000-10000 r / min to avoid agglomeration of silver nanoparticles. PDA@Ag NPs were washed three times alternately with anhydrous ethanol and deionized water and then vacuum dried.
5. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of ZCNF, PDMS and Si-PDA@AgNPs is (80-120):(20-50):(5-15); the PDMS has a number-average molecular weight of 5000-10000 and a hydroxyl content of ≥0.5%.
6. The preparation method according to claim 5, characterized in that, The optimal mass ratio of ZCNF, PDMS and Si-PDA@Ag NPs is 100:35:10, and the dry film thickness of the composite coating is controlled to be 100-120μm.
7. The preparation method according to claim 1, characterized in that, In step S3, the composite coating precursor liquid is stirred at a low speed, with the rotation speed controlled at 300-500 r / min, to prevent the introduction of air bubbles and the generation of pinhole defects. In step S4, the substrate is Q235 steel, epoxy resin coating or polyvinyl chloride, which is pretreated by sandblasting, degreasing and drying, and then left to stand for 30 minutes before coating.
8. The mussel-inspired enhanced nanocellulose composite antifouling coating prepared by the preparation method according to any one of claims 1-7.
9. The application of the mussel-inspired enhanced nanocellulose composite antifouling coating as described in claim 8 in the antifouling of marine engineering components.