Preparation and application of bionic self-compensation smooth liquid injection micro-nano surface antifouling coating

Abstract

The invention belongs to the technical field of marine organism fouling protection, and particularly discloses a preparation method of a bionic self-compensation smooth liquid injection micro-nano surface antifouling coating, which comprises the following two core steps: 1, preparing an organic silicon matrix with a bionic self-compensation function, and preparing an organic silicon matrix with a bionic self-compensation function by utilizing reversible change / dissociation-reconstruction property of a dynamic hydrogen bond; the self-repairing mechanism of the nature is simulated, and automatic compensation and continuous stability of the performance when the coating is damaged are achieved; and secondly, on the basis of the organic silicon substrate, smooth liquid is injected, and the elastic micro-nano antifouling surface is constructed in situ. Meanwhile, fluid resistance is reduced through a smooth liquid film on the surface of the coating, and recognition and attachment of fouling organisms are hindered; due to the surface design of the elastic micro-nano structure, surface damage caused by loss and deformation of a smooth liquid film on the surface of the coating can be reduced, and the long-term stable antifouling performance is kept. The two components cooperate with each other, so that the antifouling property is effectively improved, and a broad-spectrum, more efficient and lasting antifouling solution is provided for the related fields of maritime work, water conservancy and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of marine biofouling protection, and specifically relates to the preparation and application of a bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating. Background Art

[0002] The problem of biofouling has long been a severe challenge facing the field of marine engineering. Biofouling refers to the process of attachment, growth and accumulation of marine organisms (including plants, animals and microorganisms) on the surface of marine facilities. This process not only directly affects the physical properties, chemical properties and biocompatibility of marine facilities, but also invisibly threatens the safe operation and long-term stability of marine engineering facilities. From offshore ships and buoys to underwater observation equipment and aquaculture cages in shallow waters, to deep-sea detection instruments and resource development equipment, none of them are immune to the invasion of biofouling. The attachment of fouling organisms to the hull increases the navigation resistance, which in turn leads to a series of problems such as increased fuel consumption, accelerated hull corrosion and shortened service life. What is more serious is that fouling organisms may also clog the pipes and valves of ships, causing the facilities to be unable to operate normally, thereby increasing safety hazards; the clarity of underwater observation equipment and communication equipment is greatly reduced due to the coverage of fouling organisms, the stability of underwater structures is seriously threatened, and the production efficiency of aquaculture facilities is also significantly reduced due to the nuisance of fouling organisms; in deep sea areas, biological fouling not only affects the performance of detection and mining equipment, but may also accelerate the corrosion rate of deep-sea pipelines, seriously interfering with the balance of deep-sea ecosystems.

[0003] In the face of the above problems, the solutions have evolved from the initial physical methods such as manual removal and mechanical removal to the later diversified technical means such as chemical antifouling, biological antifouling and physical antifouling. Among them, the antifouling coating method has become the most commonly used and most effective antifouling method with its significant antifouling effect and wide applicability. By adding antifouling agents (such as copper oxide, tributyltin, etc.) to the coating, a layer of barrier that is toxic to organisms or not conducive to their attachment can be formed on the surface of the coating, thereby effectively preventing the attachment and growth of fouling organisms. However, the long-term use of antifouling coatings containing toxic substances will undoubtedly cause pollution to the marine environment, pose a potential threat to marine life, and may even have adverse effects on human health through the food chain. Therefore, the research and development of environmentally friendly and harmless antifouling coatings has become an important issue that needs to be urgently solved in the current field of antifouling technology.

[0004] Low surface energy silicone antifouling coatings, with their unique low surface energy characteristics, effectively prevent fouling organisms from attaching and growing on their surfaces, thereby exhibiting eco-friendly anti-biofouling behavior. In order to further improve the antifouling performance of the coating under static conditions, researchers have found that low surface energy silicone coatings with added lubricants can use the lubricating layer covering the coating surface to inhibit the recognition and attachment of fouling organisms. For example, Chinese patent CN118580763A discloses a method for preparing a tough, ultra-smooth liquid-containing coating for preventing and controlling marine microbial fouling and corrosion. The core steps include: (1) preparing a coating precursor solution, mixing linear silicone molecules, curing agents, lubricants, active small molecules and hydrophobic nano-silica particles; (2) adding the precursor solution dropwise to the substrate and volatilizing at room temperature to form a coating with a thickness of 500±30μm. This method can efficiently prepare the coating, replenish the internal liquid loss by swelling, and extend the service life. It has broad application prospects in metal corrosion protection and biofouling in marine environments. However, the method of replenishing internal liquid loss by swelling has disadvantages such as lubricant loss, stability of action and antifouling life problems, as well as difficulty in controlling coating thickness. Further research and improvement are needed to improve the long-term stability of the coating.

[0005] The micro-nano structure effectively weakens the adhesion between fouling organisms and the coating by increasing the roughness of the coating surface, and adjusts the physical and chemical properties of the coating surface, making it difficult for fouling organisms to attach and grow on it. For example, Chinese patent CN114806232B discloses a method for preparing a micro-nano structure, synthesizing silica microspheres of different sizes through multi-step reactions to form a multi-scale antifouling coating with a "lotus effect". First, a silicon-based material solution is added to an alkaline solution to generate a silica seed, and then a halide and different silicon-based materials are added to react twice to obtain silica microspheres as small as 50nm and as large as 2000nm. Then, a modified silica dispersion is obtained by silane modification, and finally mixed with an organosilicon-modified epoxy resin and coated on the surface of the substrate, and cured to form a micro-nano structure. However, the currently commonly used micro-nano structure surface preparation technology has high process complexity and poor stability. In addition, these construction methods often rely on high-precision equipment and cumbersome operating procedures, which greatly increases production costs and manufacturing difficulties. More importantly, some micro-nano structures are easily damaged or worn during long-term use, resulting in a significant decrease in anti-fouling performance, which seriously affects their lasting effect in practical applications. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a preparation method of a bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating and its application, so as to achieve a more efficient, stable and economical preparation method of the micro-nano surface antifouling coating and ensure its long-term antifouling performance.

[0007] The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating of the present invention comprises the following steps:

[0008] S1. Preparing an organic silicon matrix with a biomimetic self-compensation function: adding aminopropyl di-terminated polydimethylsiloxane and toluene-2,4-diisocyanate into a tetrahydrofuran solution, stirring and standing at room temperature to obtain an organic silicon matrix with a biomimetic self-compensation function;

[0009] S2. Preparation of smooth liquid-injected micro-nano surface organosilicon antifouling coating:

[0010] S2.1, completely dissolving the organic silicon matrix with bionic self-compensation function in S1 in tetrahydrofuran solution, injecting lubricating liquid, stirring and reacting at room temperature, and preparing a smooth liquid-injected micro-nano surface organic silicon antifouling coating prepolymer;

[0011] S2.2. Coat the smooth liquid-injected micro-nano surface organosilicon antifouling coating prepolymer on the surface of the base material to obtain a smooth liquid-injected micro-nano surface antifouling coating.

[0012] Preferably, the aminopropyl di-terminated polydimethylsiloxane and toluene-2,4-diisocyanate in S1 are added to tetrahydrofuran solution at a molar ratio of 1:1, stirred continuously for 3 to 4 hours at room temperature, and allowed to stand for 96 to 120 hours to obtain an organic silicon matrix with bionic self-compensation function.

[0013] Preferably, the organic silicon matrix having the bionic self-compensation function in S1 is a urea-doped organic silicon matrix.

[0014] Preferably, the average molecular weight (Mn) of the aminopropyl-terminated polydimethylsiloxane in S1 is 1,000 to 27,000.

[0015] Preferably, the lubricating liquid in S2.1 is one or a mixed ester of two or more of an inert oil or a fat-soluble antioxidant.

[0016] Specifically, the lubricating liquid in S2.1 is methyl silicone oil.

[0017] Specifically, the viscosity of the methyl silicone oil in S2.1 is 10 to 1000 CS.

[0018] Preferably, S2.2 is one of glass, 304 / 316 stainless steel, Q235 / Q345 carbon steel, ceramic sheet, plastic, and rubber.

[0019] The present invention also proposes the use of the smooth liquid-injected micro-nano surface antifouling coating prepared according to the above method in an anti-biological fouling coating material.

[0020] The beneficial effects of the present invention are:

[0021] Compared with the prior art, the preparation of the smooth liquid-injected micro-nano surface antifouling coating of the present invention is more efficient, stable and economical, and the obtained coating has an organosilicon matrix with a bionic self-compensation function, which uses the reversibility of dynamic hydrogen bonds to imitate natural self-repair, and realizes automatic compensation of coating damage and stable performance; at the same time, the coating can continuously inject liquid to form a lubricating layer, reduce surface fluid resistance, hinder the recognition and attachment of fouling organisms, and the elastic micro-nano structure disperses the impact force of the fluid, reduces the loss of injection, continuously forms a lubricating layer, and maintains the smoothness of the coating. The two work together to effectively improve the antifouling performance. The present invention provides a broad-spectrum, more efficient and durable antifouling solution for marine engineering, water conservancy and other related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0023] Figure 1 This is a schematic diagram of the structure of the bionic self-compensating smooth liquid-injected micro-nano surface anti-fouling coating described in the present invention.

[0024] Figure 2 This is a comparison diagram of the bionic self-compensating smooth liquid-injected micro-nano surface anti-fouling coating surface micro-nano structure (ad) and the smooth liquid-injected micro-nano surface (e) described in the present invention.

[0025] Figure 3 The invention relates to a self-compensating structural unit design of a bionic self-compensating smooth liquid-injected micro-nano surface anti-fouling coating.

[0026] In the accompanying drawings, the structural names represented by the reference numerals are:

[0027] 1-substrate; 2-smooth liquid-injected micro-nano surface coating; 3-smooth liquid-injected smooth surface coating; 4-water droplets; 5-overflowing lubricating liquid. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0029] Unless otherwise specified, the equipment used in the present embodiment, comparative example and experimental example are all conventional experimental equipment, the materials and reagents used are all commercially available unless otherwise specified, and the experimental methods without special instructions are also conventional experimental methods.

[0030] Example 1

[0031] A method for preparing a bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating comprises the following steps:

[0032] The aminopropyl di-terminated polydimethylsiloxane (average Mn-2500) and toluene-2,4-diisocyanate (TDI) placed in a refrigerator (2-5°C) were restored to room temperature, and 8-10 mL of tetrahydrofuran (THF) solution was added at a molar ratio of 1:1, and the mixture was stirred continuously for 3-4 hours at room temperature. After standing (at room temperature) for 96 hours, an organic silicon matrix with biomimetic self-compensation function was obtained; then, 0.25 g of the organic silicon polymer prepared above was weighed and completely dissolved in 2250 μL of tetrahydrofuran solution at room temperature, and 280 μL of methyl silicone oil (viscosity of 10CS) was injected, the rotation speed was maintained at 500 rpm, and stirring was continued for 1 hour to prepare an organic silicon prepolymer injected with a lubricant; finally, the obtained prepolymer was evenly coated on a substrate (2.5×7.6 cm 2 ) surface, the structure of the prepared bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating is as follows Figure 1 As shown in Figure 1, the micro-nano structures are evenly distributed on the coating surface. In the coating matrix, the organic silicon polymer molecular chains are connected by urea groups (-HN-C=O-HN-) to form a dynamic hydrogen bond reversible change area, such as Figure 2 These dynamic hydrogen bonds promote the nucleation, maturation, and uniform dispersion of the lubricating fluid in the silicone matrix throughout the coating. Figure 3 As shown in the figure, the hydrogen bonds in the coating matrix will dissociate, allowing the lubricant droplets to disperse and gradually diffuse to the coating surface, thereby compensating for the lost lubricant. When the system reaches a new equilibrium, the hydrogen bonds in the coating matrix will spontaneously reconstruct and fix the lubricant droplets formed through the nucleation-ripening process again.

[0033] Example 2

[0034] The difference from the preparation of Example 1 is that in this example, 330 μL of methyl silicone oil (viscosity of 10CS) is injected.

[0035] Example 3

[0036] The difference from the preparation in the above embodiment is that in this embodiment, 380 μL of methyl silicone oil (viscosity of 10CS) is injected.

[0037] Example 4

[0038] The difference from the preparation in the above embodiment is that in this embodiment, 420 μL of methyl silicone oil (viscosity of 10CS) is injected.

[0039] Comparative Example 1

[0040] As a control group experiment, the preparation method of the bionic self-compensating smooth liquid-injected micro-nano surface anti-fouling coating in this comparative example includes the following steps:

[0041] The aminopropyl di-terminated polydimethylsiloxane (average Mn-2500) and hexamethylene diisocyanate (HDI) placed in a refrigerator (2-5°C) were restored to room temperature, and 8-10 mL of tetrahydrofuran (THF) solution was added at a molar ratio of 1:1, and the mixture was stirred for 3-4 hours at room temperature. After standing (at room temperature) for 96 hours, a reversible dynamic hydrogen bond-doped organosilicon polymer was obtained; then, 0.25 g of the organosilicon polymer prepared above was weighed and completely dissolved in 1725 μL of tetrahydrofuran solution at room temperature, and 280 μL of methyl silicone oil (viscosity of 10CS) was injected, the rotation speed was maintained at 500 rpm, and stirring was continued for 1 hour to prepare a lubricant-injected organosilicon prepolymer; finally, the obtained prepolymer was evenly coated on a substrate (2.5×7.6 cm 2 ) surface to prepare a smooth surface antifouling coating with smooth liquid injection.

[0042] Experimental Example 1

[0043] The static contact angles of polydimethylsiloxane (PDMS), the biomimetic self-compensating smooth liquid-injected micro-nano surface antifouling coatings prepared in Examples 1, 2, 3 and 4, and the smooth liquid-injected smooth surface antifouling coating prepared in Comparative Example 1, and the mass of lubricating fluid loss caused by contact-slip were measured using a static contact angle meter. The results are shown in Table 1.

[0044] Table 1 Water static contact angle and water droplet sliding of each coating

[0045]

[0046] As can be seen from Table 1, the contact angle of the PDMS coating is the largest, which is 118.7°, indicating that the PDMS coating has the strongest hydrophobicity. In the test at 90° to the vertical plane of the coating, the water droplets on the PDMS coating are stably attached, and the water droplets did not slide off without external force. In contrast, the water droplets on the antifouling coatings of Examples 1 to 4 can all slide off successfully, and there is no residue after sliding off, and the mass loss of the lubricating fluid is 0%. Although the antifouling coating of Comparative Example 1 also has water droplets sliding off, residual tracks are generated during the sliding process, and there is a 3% loss of lubricating fluid. The experimental results show that the micro-nano structure on the coating surface can effectively avoid the loss of lubricating fluid. At the same time, the lubricating layer covering the coating surface helps the water droplets to slide off. The combination of the two makes the coating exhibit excellent antifouling properties.

[0047] Experimental Example 2

[0048] In this example, the antifouling coating prepared by PDMS and comparative example 1 was used as the control experimental group, and compared with the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating prepared by examples 1 to 4, and the antifouling adhesion experiment of the coating was carried out. The antifouling coating prepared by comparative example 1 and the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating prepared by examples 1 to 4 were kept tilted at 60° and placed under water for continuous flushing for 30 minutes. Newly inoculated and cultured Escherichia coli E.coli and Staphylococcus aureus S.aureus were used as microscopic fouling biological detection objects, and blue mussel V.atrata was used as macroscopic fouling biological detection object. The antifouling performance of the antifouling coating was detected by staining-decolorization quantitative analysis and counting method respectively. The test results are shown in Table 2.

[0049] Table 2 Quantitative analysis and counting of fouling organisms on the coating surface by spectrophotometer

[0050]

[0051] As can be seen from the above table, the antifouling performance of the antifouling coatings of Examples 1 to 4 is significantly better than that of PDMS and Comparative Example 1. E.coli and S.aureus have the largest attachment amount on the surface of the PDMS coating, with absorbance values ​​of 1.605 and 1.965, respectively, and the attachment rate of V.atrata on the coating surface is 90-100%, indicating that the antifouling effect of the PDMS antifouling coating under static conditions is poor. Compared with PDMS, the lubricating layer covered on the surface of the antifouling coating of Comparative Example 1 and Examples 1 to 4 can effectively resist the attachment and growth of fouling organisms. The absorbance values ​​of E.coli and S.aureus attached to the surface of the antifouling coating of Comparative Example 1 significantly decreased to 0.251 and 0.369, respectively, and the attachment rate of V.atrata was also reduced to 6.7-20%. The micro-nano structure on the surface of the antifouling coatings of Examples 1 to 4 reduces the loss of lubricating fluid, and the attachment amounts of E.coli, S.aureus detected on their surfaces and V.atrata observed are all 0, showing the best antifouling performance. These test results show that the lubricating layer covering the coating surface and its loss significantly affect the antifouling performance of the coating.

[0052] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the invention to only the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification.

Claims

1. A method for preparing a bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating, characterized in that: The following steps are involved: S1. Preparing an organic silicon matrix with a biomimetic self-compensation function: adding aminopropyl di-terminated polydimethylsiloxane and toluene-2,4-diisocyanate into a tetrahydrofuran solution, stirring and standing at room temperature to obtain an organic silicon matrix with a biomimetic self-compensation function; S2. Preparation of smooth liquid-injected micro-nano surface organosilicon antifouling coating: S2.1, completely dissolving the organic silicon matrix with bionic self-compensation function in S1 in tetrahydrofuran solution, injecting lubricating liquid, stirring and reacting at room temperature, and preparing a smooth liquid-injected micro-nano surface organic silicon antifouling coating prepolymer; S2.

2. Coat the smooth liquid-injected micro-nano surface organosilicon antifouling coating prepolymer on the surface of the base material to obtain a smooth liquid-injected micro-nano surface antifouling coating.

2. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 1, characterized in that: The aminopropyl di-terminated polydimethylsiloxane and toluene-2,4-diisocyanate in S1 are added into tetrahydrofuran solution in a molar ratio of 1:1, stirred continuously for 3 to 4 hours at room temperature, and allowed to stand for 96 to 120 hours to obtain an organic silicon matrix with bionic self-compensation function.

3. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 2, characterized in that: The organic silicon matrix with bionic self-compensation function in S1 is a urea-doped organic silicon matrix.

4. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 3, characterized in that: The average molecular weight of the aminopropyl-terminated polydimethylsiloxane in S1 is 1,000 to 27,000.

5. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 1, characterized in that: The lubricating liquid in S2.1 is one or a mixed ester of two or more of an inert oil or a fat-soluble antioxidant.

6. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 5, characterized in that: The lubricating liquid in S2.1 is methyl silicone oil.

7. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 6, characterized in that: The viscosity of the methyl silicone oil in S2.1 is 10-1000CS.

8. The method for preparing the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating according to claim 1, characterized in that: The S2.2 is one of glass, 304 / 316 stainless steel, Q235 / Q345 carbon steel, ceramic sheet, plastic, and rubber.

9. Use of the bionic self-compensating smooth liquid-injected micro-nano surface antifouling coating prepared according to any one of claims 1 to 8 in anti-biofouling coating materials.

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