Antifouling coating based on complex of natural wax molecules and siloxane polymer molecules and preparation method and application thereof

Abstract

The application provides an antifouling coating based on the complex of natural wax molecules and siloxane polymer molecules and a preparation method and application thereof. The preparation method realizes rapid polymerization of siloxane molecules on a smooth surface formed by natural wax through trace acid catalysis, and comprises two steps: firstly, a substrate is immersed into a molten liquid of natural wax to obtain a uniform coating layer through lifting and rotating, and a smooth and uniform wax layer is formed after the wax layer is completely solidified; secondly, dimethyl dimethoxy silane molecules are catalyzed by trace sulfuric acid to rapidly condense in a solution to form a prepolymer solution, and the substrate coated with the wax layer is immersed into the prepolymer solution of dimethyl dimethoxy silane, so that the siloxane molecules are combined with the wax layer to prepare a composite coating, which exhibits excellent antifouling capacity and has a good application prospect in the field of underwater antifouling. Moreover, the coating has low requirements for the substrate, good stability, and is non-toxic and non-polluting to the environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical and application field of biomaterials, and particularly relates to an antifouling coating based on a composite of natural wax molecules and siloxane polymer molecules and a preparation method and application thereof. BACKGROUND

[0002] Biofouling attached to the surface of underwater facilities such as ships and dams has a number of negative impacts on the human environment, energy and economic development. Among the relevant biofouling prevention and control means, antifouling coating materials account for a large part.

[0003] At present, self-polishing antifouling coating materials without organic tin still occupy the domestic and foreign coating market. Such coatings mainly release the antifouling agent filled in the coating through the hydrolysis of the base resin, kill the fouling organisms with the toxic substances in the antifouling agent, and remove the fouling on the surface of the equipment through the continuous removal of the base resin to achieve the effect of self-polishing. However, the release amount of the toxic substances in the antifouling agent is not easy to control, and its long-term release will inevitably pollute the water environment and seriously destroy the ecological balance.

[0004] Materials with low surface energy exhibit excellent performance in the fields of surface antifouling, self-cleaning and drag reduction. Fouling release type antifouling coating materials with low surface energy make it difficult for fouling organisms to form a firm adhesion layer on the material surface, thereby achieving the effect of antifouling. However, the organic silicon and organic fluorine materials used to prepare traditional low surface energy fouling release type antifouling coating materials usually have poor adhesion to the substrate and high requirements for the substrate, resulting in poor stability of the coating and unsatisfactory static antifouling ability.

[0005] Lubricated surfaces exhibit excellent sliding properties and anti-adhesion effects for a variety of substances, and play an important role in realizing fluid transportation, self-cleaning and antifouling. The creation of lubricated surfaces is related to the natural-inspired pitcher plant predation principle. In 2011, the Aizenberg team developed a technology for injecting a lubricating liquid into a porous surface (Slippery Porous Lubricant-infused Surfaces, SLIPS), i.e. injecting a low surface energy liquid (such as silicone oil) into a material surface with interconnected pores to prepare a liquid surface with super-slip effect, making it difficult for fouling organisms to adhere to its surface. However, in underwater environments, the liquid lubricant is prone to seep out of the porous surface, resulting in poor stability of the coating, i.e. the long-term stability of the SLIPS system in water still faces great challenges.

[0006] Studies have shown that grafting flexible molecules on a smooth surface is an effective strategy for preparing lubricated surfaces (the "liquid-like" strategy), which provides lubrication in liquid-like surfaces by chemically bonding flexible molecules to a relatively smooth surface, which makes the coating more stable. Currently, methods including vapor deposition, heat treatment, ultraviolet irradiation, and complementary bonding of end-functionalized groups are used to prepare liquid-like surfaces. Among these methods, the requirements for flexible molecule polymers on the substrate are relatively strict, and the substrate needs to be treated with hydroxyl groups or special reactive group functionalization to form a chemical bond with the polymer, which not only increases the complexity and cost of coating preparation, but also makes it difficult to mass-produce such coatings.

[0007] There are many problems in the reported methods. First, the flexible molecule layer that plays a key lubricating function is easily eroded by the external environment in actual underwater applications, losing its lubricating effect. Moreover, the thickness of the flexible molecule layer prepared by the current process is in the nanometer range, generally less than 100 nanometers, while in actual applications, such as ship surfaces, the roughness is usually in the micrometer range. Therefore, the flexible molecule layer prepared by the existing method cannot fully cover the real object surface, and its sliding property is greatly reduced. In addition, high surface roughness will further increase the possibility of damage to the flexible molecule layer. In summary, the overall tolerance of the coating obtained by the current reported process is low. Second, the prerequisite for the flexible molecule layer to bond with the object surface is that the object surface contains necessary functional groups, such as hydroxyl groups. However, the object surface, such as a ship surface, usually contains a corrosion-resistant layer, such as paint, and the surface of the corrosion-resistant layer is inert and almost does not contain active functional groups. Therefore, how to effectively graft flexible molecules on the object surface and prepare an underwater-resistant high-performance antifouling coating is a challenging topic. More importantly, according to our observations, the lubricating performance of the coating is not the only determinant of its underwater antifouling performance. The anti-bioadhesion performance of the coating in water is related to the chemical properties of the coating, such as the types and amounts of chemical functional groups. Therefore, on the basis of the flexible molecule layer, we should also explore new antifouling strategies to synergistically improve the underwater antifouling performance of the coating. SUMMARY

[0008] The purpose of the present application is to provide an antifouling coating based on the combination of natural wax molecules and siloxane polymer molecules, as well as its preparation method and application, to introduce a substance that can form a film easily and cover the substrate surface sufficiently, form a smooth surface layer on the object surface, reduce the roughness of the object, and the substance contains rich chemical functional groups.

[0009] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0010] The first object of the present application is to provide a preparation method of an antifouling coating based on the complex of natural wax molecules and siloxane polymer molecules, comprising the following specific steps:

[0011] S1, immersing the substrate into a molten solution of natural wax, obtaining a uniform coating layer by pulling and rotating, and forming a smooth and uniform wax layer after the wax layer is completely solidified;

[0012] S2, mixing siloxane monomer molecules with isopropyl alcohol and adding concentrated sulfuric acid to form a prepolymer solution by rapid polycondensation;

[0013] S3, immersing the substrate coated with the wax layer into the prepolymer solution of siloxane monomer molecules, so that the siloxane molecules are complexed with the wax layer to form a stable polysiloxane oligomer molecular layer.

[0014] Further, the natural wax after melting covers the substrate completely, and the thickness of the natural wax layer covering the surface of the substrate is 0.1-100 microns.

[0015] Further, the volume ratio of the siloxane monomer molecules to the isopropyl alcohol is 1: (4-5), and the volume ratio of the siloxane monomer molecules to the concentrated sulfuric acid is 2 mL: (100-120) microliters.

[0016] Further, the natural wax includes palm wax or beeswax.

[0017] Further, the siloxane monomer molecules include dimethyldimethoxysilane.

[0018] Further, in step S1, the preparation process of the molten solution of natural wax is as follows: weighing the natural wax in a beaker, heating in a water bath pot at 80-85°C, continuing to heat and homogenize for 20-60 minutes after the solid natural wax is completely converted into liquid, completely discharging the bubbles in the molten solution, and then keeping in the water bath pot for standby.

[0019] Further, in step S1, the solidification time is 2-6 hours.

[0020] The second object of the present application is to use the antifouling coating prepared by the above preparation method.

[0021] Further, the sliding angle of the composite coating is: under 10 microliter droplets, the sliding angle is less than 40 0 .

[0022] The second object of the present application is the application of the antifouling coating prepared by the above preparation method in the preparation of underwater antifouling products.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] (1) The application provides a preparation method of an antifouling coating based on the complex of natural wax molecules and siloxane polymer molecules, which realizes rapid polymerization of siloxane molecules on a smooth surface formed by natural wax through trace acid catalysis, and comprises two steps: one is that a substrate is immersed into a molten liquid of natural wax to obtain a uniform coating layer through a lifting and rotating mode, and a smooth and uniform wax layer is formed after the wax layer is completely solidified; the other is that a pre-polymer solution is formed by rapid polycondensation of dimethyl dimethoxy silane molecules in a solution under the catalysis of trace sulfuric acid, and the substrate coated with the wax layer is immersed into the pre-polymer solution of dimethyl dimethoxy silane, so that the siloxane molecules are combined with the wax layer to form a stable polysiloxane oligomer molecular layer (DMS). The combination of the two substances has lubricating function, and the two substances have synergistic effect due to the rich chemical functional groups in the natural wax substance, so that the combined coating has excellent antifouling capacity.

[0025] (2) The application utilizes the complexing capacity of natural wax and siloxane polymer to prepare a combined coating on a relatively rough and inert substrate surface. The coating has a significant influence on the surface physical and chemical properties and wettability of the material surface, and greatly improves the antifouling capacity of the substrate surface. The micro-nano structure of the coating endows the material surface with good hydrophobic property; the synergistic effect of the low surface energy, lubricating effect and rich functional groups of the natural wax substance and the flexible molecular layer makes the coating have good antifouling capacity; the coating has excellent anti-adhesion effect on inorganic nanoparticles, proteins, marine microalgae and other pollutants. The underwater hanging plate experiment shows that the coating can reduce the adhesion of sludge, algae and other pollutants in water to a certain extent in a static water environment. And due to the easy availability, green and non-toxic, low price, renewable, good film forming ability and other characteristics of the raw material natural wax, the preparation method of the coating is simple, the requirement for the substrate is not high, the stability is good, and the coating is non-toxic and non-polluting to the environment, which is a promising coating material in the field of underwater antifouling.

[0026] (3) Due to the relatively low surface energy and stable complexing effect of the two raw material molecules, the coating has low surface energy and excellent lubricity, and the pollutant molecules are not easy to adhere to the surface, so the coating has good anti-adhesion effect on various pollutants. The main raw materials of the combined coating are natural wax (such as palm wax CW and beeswax BW and other waxes with active hydroxyl or hydroxyl fatty acid ester) and siloxane monomer molecules. The natural wax has excellent film forming property, and the molten natural wax has good flow effect, can quickly form a film on the substrate surface, and more importantly, the natural wax contains rich chemical functional groups, can have synergistic effect with the flexible molecular layer, and increase the underwater anti-bio-adhesion performance of the coating; the siloxane monomer molecules (such as dimethyl dimethoxy silane) are polymerized into siloxane oligomers under the catalysis of trace sulfuric acid, and the silane chain has good flexibility and is easy to form a lubricating surface. The natural wax cooperates with the siloxane oligomer molecules with lubricating effect through active groups to form a stable combined coating. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 a and 1b Figure 6 is a comparison chart of the Wiener structure and roughness of the DMS@CW coating and the DMS@BW coating;

[0028] Figure 2 Figure 7 is a chart showing the changes in surface energy, wettability and sliding property of the substrate surface before and after modification of the substrate by the DMS@CW coating and the DMS@BW coating, respectively;

[0029] Figure 3 Figure 8 is a chart showing the stability of the DMS@CW coating and the substrate;

[0030] Figure 4 Figure 9 is a chart showing the antifouling effect of the DMS@CW coating on proteins;

[0031] Figure 10 is a chart showing the antifouling effect of the DMS@CW coating on marine microalgae;

[0032] Figure 6 Figure 11 is a chart showing the antifouling effect of the DMS@CW coating on nanoparticles;

[0033] Figure 7 Figure 12 is a chart showing the underwater antifouling effect of the DMS@CW coating. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present application clearer, the specific embodiments of the present application will be further described in detail below with reference to the specific examples and drawings. If the specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in the art or according to the product instructions are used. If the reagents or instruments are not specified by the manufacturer, they are all conventional products that can be obtained commercially.

[0035] In the implementation process, the natural wax is melted to completely cover the substrate. The thickness of the natural wax layer covering the substrate surface can be 0.1 μm to 100 μm.

[0036] In this example, the contact angle and sliding angle were measured: a contact angle / interface tension measuring instrument was used to test the wettability of the coating surface; the test liquids were water and n-hexadecane; for contact angle testing, the volume of the liquid was 10.0 μL, and the contact angle was measured 5 times at different positions of each sample, and the average value was taken; for sliding angle testing, the volume of the liquid was 10.0 μL, and the sliding angle was measured 5 times at different positions of each sample, and the average value was taken.

[0037] Example 1

[0038] (1) Pretreatment of the material substrate:

[0039] The substrate was placed in an ultrasonic cleaner and washed with deionized water for 10 min, then dried with nitrogen and washed with anhydrous ethanol for 10 min, dried with nitrogen and used.

[0040] (2) Preparation of palm wax melt solution:

[0041] 30.0 g of flaky carnauba wax was weighed into a 100 ml beaker, heated in a 85°C water bath, and after the solid carnauba wax was completely converted into a liquid, the heating was continued for 30 min to homogenize, and the gas bubbles in the melt solution were completely discharged, and then the water bath was used for preservation.

[0042] (3) Preparation of DMS prepolymer solution:

[0043] 2.0 mL of dimethyl dimethoxy silane solution was mixed with 10.0 mL of isopropyl alcohol, 100 μL of concentrated sulfuric acid was added, and it was stirred at room temperature on a magnetic stirrer at 4500 rpm for 10 min. The prepolymer solution was prepared and used immediately.

[0044] (4) Preparation of DMS@CW composite coating

[0045] The surface of the ship plate substrate (2 cm x 2 cm) was modified by immersion coating, the pretreated ship plate was immersed in the palm wax melt solution, and after preheating, it was vertically lifted and continuously rotated until a uniform palm wax coating layer was formed. After taking out, it was placed at room temperature for natural curing for 3 h. The cured palm wax coated substrate was immersed in the DMS prepolymer solution, taken out directly after 30 s, and placed at room temperature. After the solvent on the surface of the wax layer was naturally volatilized, a siloxane oligomer molecular composite layer was formed.

[0046] Example 2

[0047] (1) Pretreatment of material substrate:

[0048] The substrate was placed in an ultrasonic cleaner and washed with deionized water for 10 min, then dried with nitrogen and washed with anhydrous ethanol for 10 min, dried with nitrogen and used.

[0049] (2) Preparation of palm wax melt solution:

[0050] 30.0 g of flaky carnauba wax was weighed into a 100 ml beaker, heated in a 85°C water bath, and after the solid carnauba wax was completely converted into a liquid, the heating was continued for 30 min to homogenize, and the gas bubbles in the melt solution were completely discharged, and then the water bath was used for preservation.

[0051] (3) Preparation of DMS prepolymer solution:

[0052] Take 2.0 mL of dimethyl dimethoxy silane solution and mix with 10.0 mL of isopropyl alcohol, add 100 μL of concentrated sulfuric acid, and stir at room temperature on a magnetic stirrer at 4500 rpm for 10 min. The prepolymer solution is prepared fresh.

[0053] (4) Preparation of DMS@CW composite coating

[0054] The surface of the ship plate substrate (2 cm x 2 cm) is modified by dip coating. The pretreated ship plate is immersed in the palm wax melt, and after preheating, it is vertically lifted and continuously rotated until a uniform palm wax coating layer is formed. After taking it out, it is naturally solidified at room temperature for 3 h. The solidified palm wax coated substrate is immersed in the DMS prepolymer solution, and after 1 min, it is taken out directly and placed at room temperature. After the solvent on the surface of the wax layer naturally evaporates, a molecular composite layer of siloxane oligomers is formed.

[0055] Example 3

[0056] (1) Pretreatment of material substrate:

[0057] The substrate is placed in an ultrasonic cleaner and washed with deionized water for 10 min. After blowing dry with nitrogen, it is washed with anhydrous ethanol for 10 min and dried with nitrogen.

[0058] (2) Preparation of palm wax melt:

[0059] Weigh 30.0 g of flaky Brazilian palm wax into a 100 ml beaker, place it in a 85°C water bath, heat until the solid Brazilian palm wax is completely converted into liquid, continue to heat and homogenize for 30 min, and then remove the air bubbles in the melt. Keep warm in the water bath.

[0060] (3) Preparation of DMS prepolymer solution:

[0061] Take 2.0 mL of dimethyl dimethoxy silane solution and mix with 10.0 mL of isopropyl alcohol, add 120 μL of concentrated sulfuric acid, and stir at room temperature on a magnetic stirrer at 4500 rpm for 20 min. The prepolymer solution is prepared fresh.

[0062] (4) Preparation of DMS@CW composite coating

[0063] The surface of the ship plate substrate (2 cm x 2 cm) is modified by dip coating. The pretreated ship plate is immersed in the palm wax melt, and after preheating, it is vertically lifted and continuously rotated until a uniform palm wax coating layer is formed. After taking it out, it is naturally solidified at room temperature for 3 h. The solidified palm wax coated substrate is immersed in the DMS prepolymer solution, and after 1 min, it is taken out directly and placed at room temperature. After the solvent on the surface of the wax layer naturally evaporates, a molecular composite layer of siloxane oligomers is formed.

[0064] Example 4

[0065] (1) Material substrate pretreatment:

[0066] The substrate was placed in an ultrasonic cleaner and washed with deionized water for 10 min, then dried with nitrogen and washed with anhydrous ethanol for 10 min, dried with nitrogen and used.

[0067] (2) Preparation of beeswax melt solution:

[0068] 15.0 g of block beeswax was weighed into a 100 ml beaker, placed in a 75°C water bath, heated until the beeswax was completely converted into a liquid, and then heated for 30 min to homogenize, so that the bubbles in the melt solution were completely discharged, and then stored in the water bath for use.

[0069] (3) Preparation of DMS prepolymer solution:

[0070] 2.0 mL of dimethyl dimethoxy silane solution was mixed with 10.0 mL of isopropyl alcohol, 100 μL of concentrated sulfuric acid was added, and it was stirred at room temperature on a 4500 rpm magnetic stirrer for 20 min. The prepolymer solution was prepared and used immediately.

[0071] (4) Preparation of DMS@BW composite coating

[0072] The surface of the ship plate substrate (2 cm x 2 cm) was modified using dip coating method, the pretreated ship plate was immersed in the beeswax melt solution, preheated, then vertically pulled and continuously rotated until a uniform beeswax coating layer was formed. After taking out, it was placed at room temperature for natural curing for 3 h. The cured beeswax coated substrate was immersed in the DMS prepolymer solution, taken out after 1 min, and placed at room temperature. After the solvent on the surface of the wax layer was naturally volatilized, a siloxane oligomer molecular composite layer was formed.

[0073] In order to better explore the decontamination performance of the lubricating coating provided by the application, the applicant conducted the following research:

[0074] (1) Comparison of microstructure and roughness map

[0075] As shown in Figure 1 a and 1b , in the figure, DMS@CW is prepared by Example 1, and DMS@BW is prepared by Example 4.

[0076] The microstructure of the DMS@CW coating is mainly nanoscale wrinkle, the distribution of the wrinkle is relatively uniform and dense. The average roughness of the coating is 0.99 μm (Ra), the root mean square roughness (Rq) is 1.35 μm, and the surface is smooth and has a certain glossiness in the macro state, and the thickness is 93.3 μm.

[0077] DMS@BW coating surface exists many uneven block protrusions, the block protrusions and the middle ditch form a corrugated structure. The diameter of the block protrusions is about 10-25 μm, the average roughness of the coating is 1.04 μm (Ra), and the root mean square roughness (Rq) is 1.27 μm. The macrostate forms a smooth surface.

[0078] The average roughness of the original substrate is 1.31 μm (Ra), and the root mean square roughness (Rq) is 1.6 μm. Compared with the original substrate, the two coatings both reduce the surface roughness of the substrate, and form a smoother surface.

[0079] (2) Study on the surface energy, wettability and slipperiness of the ship plate substrate before and after modification by different coatings.

[0080] As shown in Figure 2 , DMS@CW is prepared in Example 2, and DMS@BW is prepared in Example 4.

[0081] As shown in Figure 2 , the ship plate substrate without coating has a high surface energy (36.09 mJ / m 2 ), and the liquid droplets are in a sticky state on the surface. The surface energy of the ship plate substrate coated with a natural wax layer is greatly reduced, wherein the surface energy of the substrate coated with a palm wax layer is 21.08 mJ / m 2 , and the surface energy of the substrate coated with a beeswax layer is 18.18 mJ / m 2 . After the wax layer is combined with the siloxane polymer molecules, the surface energy of the coating is basically unchanged (change value 2.00±1 mJ / m 2 ), and the siloxane polymer molecule layer gives the coating excellent lubrication effect, wherein the sliding angle (SA) of the liquid droplets on the DMS@CW coating is 18.16°, and the sliding angle (SA) of the liquid droplets on the DMS@BW coating is 18.37°.

[0082] (3) Stability study of the DMS@CW coating combined with the substrate

[0083] The DMS@CW coating prepared in Example 3 is used for the test.

[0084] The substrate adhesion of the coating is tested by using the ASTM standard. First, a grid is drawn on the surface of the coating with a blade, then a 3M tape is adhered to the grid mark, a force is applied with tweezers to exclude the gap between the tape and the coating, and after 1 min, the 3M tape is torn along the two sides of the tape with a horizontal upward force, and whether there is a falling phenomenon in the grid area and the edge of the mark is observed under a scanning electron microscope.

[0085] As shown in Figure 3As can be seen from the scanning electron microscope, there was no peeling of the coating in the grid area and the edge of the scratch, indicating that the coating has good adhesion to the steel plate substrate and the coating has good stability in bonding with the substrate.

[0086] (4) Study on the antifouling effect of DMS@CW coating on proteins

[0087] The DMS@CW coating prepared in Example 1 was used for testing.

[0088] FITC-labeled bovine serum albumin and human IgG protein were used as adhesion proteins. The proteins were dissolved in PBS buffer solution at pH 0.4 to a concentration of 1 mg / mL. A region was selected on the coating and marked with a blade. The prepared protein buffer was then dropped onto the test area and left to stand in the dark at room temperature for 4 hours, followed by rinsing with PBS buffer. The adhesion of proteins within the region was observed and recorded using a two-photon confocal microscope.

[0089] Depend on Figure 4 It was observed that both proteins emitted strong fluorescence on the ship plate substrate, almost covering the entire area. However, the DMS@CW coating showed less protein adhesion, with only weak fluorescence observed under a microscope. The fluorescence intensity within the area was quantified, and the fluorescence intensity of the control group was set as 100.00%, termed the adhesion rate of 100.00%. The adhesion rate of bovine serum albumin (BSA) with the DMS@CW coating was 37.70%, while the adhesion rate of human IgG protein (IgG) was only 0.16%. This indicates that the DMS@CW coating can significantly reduce protein adhesion and possesses excellent anti-protein adhesion capabilities.

[0090] (5) Study on the antifouling effect of DMS@CW coating on marine microalgae

[0091] The DMS@CW prepared in Example 1 and the DMS@BW prepared in Example 4 were used in the experiment.

[0092] The algal species was *Gastrodia tsao-ko*, with a size of several micrometers. The initial concentration of the algal species was about 10⁴ cells / mL. It was co-cultured with the sample on the 7th day of propagation at a temperature of 20℃ to 28℃, with a light duration of 8 to 16 hours per day and shaking in the morning and evening.

[0093] Depend on Figure 5aIt can be seen that the degree of algae adhesion on the blank is particularly serious, and the seaweed adhered to the blank almost covers the entire surface within 15 days. From 15 days to 30 days, the adhesion amount of the algae continues to rise. The pictures show that the density and thickness of the adhered algae are increasing, and the surface of the blank is seriously contaminated by algae. The adhesion amount of algae on the DMS@CW coating is relatively low, and the adhesion amount of algae on the DMS@CW coating is relatively low. From 15 days to 30 days, the adhesion density and thickness of the algae on the coating surface almost do not change. The DMS@BW coating is slightly contaminated by algae within 15 days, and the adhesion amount of algae gradually increases from 15 days to 30 days.

[0094] By Figure 5b It can be seen that the adhesion area of the algae is quantitatively processed, and the adhesion area of the algae in the control group is set to 100.00%, and the adhesion area of the algae on the DMS@CW coating is 27.08% on the 15th day, and the adhesion area of the algae on the 30th day is 43.06%, indicating that the adhesion speed of the coating in the static seawater environment is slow, and has good static anti-algae ability. The adhesion area of the algae on the DMS@BW coating is 73.26% on the 15th day, and the adhesion area of the algae on the 30th day is almost 100%.

[0095] (6) Study on the antifouling effect of DMS@CW coating on nanoparticles

[0096] The DMS@CW coating prepared in Example 3 was used for testing.

[0097] Titanium dioxide (TiO2) nanoparticles with a diameter of 100 nm were used for testing, and 2 g of TiO2 nanoparticles were dispersed in 20 mL of ultrapure water to obtain a concentration of 2 g / mL of TiO2 nanoparticle suspension. A square area with a length of 0.5 cm and a width of 0.5 cm was selected on the surface of the prepared coating and marked with a blade. 20 μL of prepared TiO2 nanoparticle suspension was dropped on the square test area with a pipette, and after 1 min, the liquid was absorbed from the edge of the area with filter paper, and after repeating the operation for 10 times, the sample was dried with nitrogen. The adhesion of TiO2 nanoparticles in the test area was observed and recorded under a scanning electron microscope.

[0098] By Figure 6It is evident that a large number of nano-TiO2 particles remain on the surface of the ship plate substrate. Besides the surface-stacked nano-TiO2 particles, a significant amount are also hidden in surface defects and depressions. In contrast, very few nano-TiO2 particles remain on the relatively smooth surface of the DMS@CW coating. Quantifying the nano-TiO2 particle coverage area within the region, with the control group ship plate's nano-TiO2 particle coverage area set at 100.00%, reveals that the DMS@CW coating surface has a nano-TiO2 particle coverage area of ​​only 1.88%, indicating that the coating exhibits excellent anti-adhesion properties against inorganic nanoparticles.

[0099] (7) Study on the underwater antifouling effect of DMS@CW coating

[0100] The DMS@CW coating prepared in Example 2 was used for testing.

[0101] A self-made simulated hanging device was used to vertically suspend samples measuring 3.0cm × 3.0cm at a depth of approximately 30cm to 50cm above the water surface. The underwater hanging was conducted during March-April and July-August each year, coinciding with the peak reproductive periods of aquatic organisms such as algae and snails, at water temperatures of approximately 15℃ to 25℃. After 30 days, the samples were removed, and the surface contaminants were gently rinsed with pure water before the degree of contamination was recorded.

[0102] Depend on Figure 7 Macroscopic images show that the surface of the ship plate substrate was severely contaminated within 30 days, with the entire paint surface almost completely covered by sludge and algae from the water. In contrast, the DMS@CW coating showed less contamination on day 30, with contaminants not completely obscuring the original morphology of the coating. Microscopic morphology comparison revealed that the contaminants adhering to the ship plate surface had reached a considerable thickness, almost completely covering the original morphology, while the contaminant coverage on the DMS@CW coating surface was sparse, with only some areas covered by contaminants. Furthermore, the DMS@CW coating did not bubble or peel off during a month of underwater immersion, indicating that the DMS@CW coating reduces the adhesion of contaminants to the ship plate surface in still water environments, demonstrating its potential application in underwater antifouling.

[0103] For any points not covered above, existing technologies shall apply.

[0104] Although some specific embodiments of the present application have been described in detail by way of example with reference to the drawings, it is to be understood that the above examples are intended to be illustrative only and are not intended to limit the scope of the present application, which is defined in the appended claims. It is to be understood that various modifications or improvements or substitutions of equivalent techniques can be made by those skilled in the art to the specific embodiments described without departing from the spirit or scope of the present application. It is to be understood that any modification, equivalent substitution, improvement, etc. made to the above embodiments in accordance with the technical essence of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing an antifouling coating based on the complexation of molecules of natural wax with molecules of siloxane polymer, characterized in that, Comprise the following specific steps: S1, the substrate is immersed in the molten liquid of natural wax, the uniform thickness of the coating layer is obtained by the way of pulling and rotating, and the smooth and uniform wax layer is formed after the complete solidification of the wax layer; the natural wax is palm wax; S2, dimethyl dimethoxysilane is mixed with isopropyl alcohol, concentrated sulfuric acid is added, and pre-polymer solution is formed by rapid polycondensation; the volume ratio of dimethyl dimethoxysilane to isopropyl alcohol is 1: (4-5), and the volume ratio of dimethyl dimethoxysilane to concentrated sulfuric acid is 2 mL: (100-120) μL S3, the substrate coated with the wax layer is immersed in the pre-polymer solution of siloxane monomer molecules, so that the siloxane molecules are compounded with the wax layer to form a stable polysiloxane oligomer molecular layer.

2. The production method according to claim 1, wherein The molten natural wax at least completely covers the substrate, and the thickness of the natural wax layer covering the surface of the substrate is 0.1 μm-100 μm.

3. The production method according to claim 1, characterized by, In step S1, the preparation process of the molten liquid of the natural wax is as follows: the natural wax is weighed in a beaker, heated in a 80-85℃ water bath, and then heated and homogenized for 20-60 min after the solid natural wax is completely converted into liquid, so that the gas bubbles in the molten liquid are completely discharged, and then the molten liquid is preserved in the water bath for standby.

4. The production method according to claim 3, characterized by, In step S1, the solidification time is 2-6h.

5. An antifouling coating prepared by the preparation method of any one of claims 1-4.

6. The antifouling coating according to claim 5, characterized in that The anti-fouling coating has a droplet sliding angle of: 10 μL droplet, sliding angle < 40 0 .

7. Use of the antifouling coating of claim 5 or 6 in the preparation of underwater antifouling products.

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