A super-slippery anti-fouling coating with a high-adhesion biofilm structure and a preparation method thereof

Abstract

The present invention discloses a super-slippery anti-fouling coating with a highly adhesive biofilm structure and a preparation method thereof, belonging to the technical field of marine anti-fouling and anti-corrosion. The present invention is a SLIPS with an anti-corrosion biofilm structure, which uses the biofilm as a scaffold structure and has nanoscale textures. A stable rough structure is formed by the growth of the biofilm and adhered to the surface of the substrate material. The anti-corrosion biofilm structure is subjected to silanization treatment to make the surface of the biofilm in a lipophilic and hydrophobic state, which is more conducive to compounding with the lubricant. The super-slippery anti-fouling coating with a highly adhesive biofilm structure of the present invention is an effective strategy for marine anti-fouling, and has a universal super-slippery anti-fouling effect on corrosive media, proteins, bacteria, algae, etc. It has stability and universality when used to prevent marine biofouling and corrosion, with a protein resistance of 72.3%, a bacteria resistance of 96.28%, and an algae resistance of 85.72%, and has excellent corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine anti-fouling and anti-corrosion, and particularly relates to a super-slippery anti-fouling coating with a high-adhesion biofilm structure and a preparation method thereof. Background Art

[0002] Marine corrosion and biofouling are the most serious threats to the safety of marine engineering equipment and offshore structures. The high-salt environment accelerates the corrosion of marine engineering equipment and offshore structures. Moreover, marine biofouling has harmful effects on marine aquaculture, shipping, and oil extraction. These fouling organisms colonize on the underwater surface, resulting in impaired equipment performance, increased fuel consumption, or structural damage. The characteristics of biological fouling are the harmful accumulation of biological molecules and microorganisms, which pose a serious threat to public health, marine infrastructure, and the offshore. This microorganism-mediated process can also accelerate the deterioration of metals by establishing a corrosive microenvironment and promoting microbial corrosion, with harmful consequences for economic development and environmental damage. In the past few decades, liquid-repellent surfaces have emerged as a promising strategy for mitigating biofouling. The lotus leaf-inspired superhydrophobic surface, with surface textures that trap air and low surface chemical energy, effectively repels water droplets and inhibits the adhesion of fouling organisms. However, this external metastable air cushion is easily collapsed under harsh marine conditions (such as high temperature, high pressure, and high humidity). The resulting Cassie state to Wenzel state transition significantly reduces the droplet mobility and induces surface pinning, providing ecological sites for biofouling colonization. The persistent surface colonization can exacerbate metal corrosion by up to four orders of magnitude. Inspired by Nepenthes, a recent study proposed a slippery liquid-infused porous surface (SLIPS) as an alternative to traditional superhydrophobic surfaces, which is of great significance for metal protection.

[0003] Although those skilled in the art are committed to carefully designing various super-slippery coatings controlled by surface topography and chemical characteristics, currently, the methods for designing highly structured roughness first involve harsh and time-consuming preparation procedures. The increased cost of the materials used, low stability, and unsustainable production have greatly hindered large-scale applications. Secondly, few solutions can fabricate complex nanoscale textures compatible with various substrates (such as metals, ceramics, polymers, and fabrics), especially on the inner surface of enclosed cavity spaces. Finally, due to the paradox of intrinsic surface roughness, it seems difficult to simultaneously achieve interfacial slipperiness, high light transmittance, and mechanical flexibility in a single coating, which hinders the realization of a universally applicable repellent surface.

[0004] Microorganisms ubiquitous in nature have evolved to immobilize themselves in one place, forming a flexible biofilm interface on the Earth's surface to protect themselves from harsh environments, rather than as planktonic cells. Compared with traditional organic and inorganic platforms, biofilms containing more than 90% (w / w) extracellular polymeric substances (EPS) provide a unique three-dimensional network with a high surface area, adjustable surface chemical energy, and strong interfacial adhesion. Theoretically, it is an ideal structure that conforms to the rough structure of a super-slippery coating. However, most microorganisms exhibit highly dynamic growth behavior and weak and unstable biofilm-forming ability, which limits their attachment to material interfaces.

[0005] Regarding the research on the preparation of super-slippery coatings with multiple functions of anti-corrosion and anti-fouling, there is currently a metal matrix surface composite coating and its preparation method and application with patent publication number CN117926362A, and an electrodeposition method for a super-hydrophobic and super-slippery coating on the surface of weathering steel with patent publication number CN116288576A. The above super-slippery coatings create roughness on the metal surface through relatively complex micro-arc oxidation and electrodeposition methods. Such coatings have two disadvantages: one is that they can only be applied on metal surfaces and it is difficult to be successfully prepared on various substrates, lacking universality; the other is that the manufacturing method is complex, time-consuming, and has high requirements for the conditions required in the manufacturing process. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the research purpose of the present invention is to provide a super-slippery anti-fouling coating with a high-adhesion biofilm structure and its preparation method. Based on the SLIPS of the anti-corrosion biofilm structure, using the biofilm as a support structure, a stable rough structure is formed by the growth of the biofilm and attached to the surface of the substrate material. There are ionic bonds and chemical bonds between the EPS in the bacterial biofilm and the substrate material, with better adhesion. After the anti-corrosion biofilm structure is treated by silanization, the surface of the biofilm is in a lipophilic and hydrophobic state, which is beneficial for compounding with lubricants to obtain a super-slippery coating with multiple functions such as universality, scalability, difficult adsorption, antibacterial and anti-fouling, and has a universal super-slippery anti-fouling effect on corrosive media, proteins, bacteria, and algae.

[0007] To achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0008] The present invention provides a preparation method for a super-slippery anti-fouling coating with a high-adhesion biofilm structure, including the following steps:

[0009] Step 1: Culture Mesophilic Adhesive Bacillus, adjust the bacterial concentration to obtain a bacterial culture solution, place the material sample in the bacterial culture solution for culture, and cover the biofilm support structure on the surface of the material sample;

[0010] Step 2: Moderately aseptically rinse the material sample covering the biofilm support structure to remove planktonic bacteria, and fix it with glutaraldehyde to obtain the biofilm material sample substrate;

[0011] Step 3: Activate the biofilm material sample substrate to remove adsorbed water on the surface and generate more surface reactive groups;

[0012] Step 4: Perform dry or wet silanization treatment on the activated biofilm material sample substrate, deposit hydrophobic silane on the surface of the biofilm structure of the material sample to obtain a hydrophobic-biofilm structure coating on the material sample;

[0013] Step 5: Inject the lubricant into the hydrophobic-biofilm structure coating of the material sample, absorb it by capillary force to form an outer coating, adjust the tilt angle of the material sample to make the lubricant evenly and fully cover the surface of the hydrophobic-biofilm structure coating of the material sample, and obtain a super-slippery anti-fouling coating with a highly adhesive biofilm structure.

[0014] Further, in step 1, the mesophilic adherent bacillus is cultured by inoculating the isolated single colony of mesophilic adherent bacillus into 2216E liquid medium by the streak plate method, the culture temperature is 20°C - 40°C, and the culture is carried out until the logarithmic growth phase.

[0015] Further, in step 1, the bacterial concentration is adjusted to 10 5 CFU / mL - 10 8 CFU / mL.

[0016] Further, the material sample in step 1 includes metal, glass and polymer. The metal sample is surface polished, cleaned and dried before being placed in the bacterial culture solution, and the glass and polymer are cleaned and dried before being placed in the bacterial culture solution; the time for the material sample to be cultured in the bacterial culture solution is 3 days - 5 days.

[0017] Further, in step 2, the aseptic rinse is carried out using aseptic phosphate buffer (aseptic PBS solution);

[0018] In the glutaraldehyde fixation, the concentration of glutaraldehyde is 2% - 6% (v / v), and the fixation time is 2h - 8h.

[0019] Further, in step 3, the activation is carried out by oxygen plasma treatment for 1 min - 5 min.

[0020] Further, in step 4, for the dry silanization treatment, the biofilm material sample is placed in a vacuum dryer and subjected to chemical vapor deposition treatment with n-octyltriethoxysilane at room temperature; realizing the in-situ hydrolysis and condensation reaction of silane on the biofilm;

[0021] Wet silanization treatment involves immersing the biofilm material sample in an ethanol / water solution containing n-octyltriethoxysilane.

[0022] Furthermore, in the dry silanization treatment of step 4, chemical vapor deposition with n-octyltriethoxysilane is carried out for 12 h - 36 h.

[0023] In the wet silanization treatment, the volume ratio of n-octyltriethoxysilane to the ethanol / water solution is 1:1, and the immersion time is 3 h - 6 h.

[0024] Further, in step 5, the lubricant is silicone oil.

[0025] The present invention provides a super-slippery anti-fouling coating with a highly adhesive biofilm structure, which is prepared using the preparation method of the super-slippery anti-fouling coating with a highly adhesive biofilm structure. The super-slippery anti-fouling coating is a porous surface (SLIPS) injected with a smooth liquid of an anti-corrosion biofilm structure, using the biofilm as a scaffold structure, having nanoscale textures, depositing hydrophobic silane on the surface of the biofilm structure, and compounding with a lubricant.

[0026] Compared with the prior art, the super-slippery anti-fouling coating with a highly adhesive biofilm structure and its preparation method of the present invention have the following beneficial effects:

[0027] 1. The present invention innovatively uses self-growing organisms to define the interface morphology, making it have certain characteristics to facilitate the fabrication of scalable integrated coatings. Based on the characteristics of natural anti-corrosion biofilms and porous surfaces injected with lubricants, the smooth surface is combined with unique biopolymers; by depositing hydrophobic silane and then injecting the lubricant in an in-situ liquid curing manner, a uniform and conformal super-slippery anti-fouling coating with a highly adhesive biofilm structure is prepared, which can achieve the dual mitigation of biofouling and microbial corrosion under complex marine environmental conditions, and provide broad-spectrum corrosion resistance to corrosive media, proteins, bacteria, and algae.

[0028] 2. The present invention not only successfully realizes the natural anti-corrosion biofilm as a source of the rough structure of the multifunctional coating, but also provides a highly adaptable biofilm-derived interface for potential applications across the energy, environment, and biomedical fields.

[0029] 3. Under mild conditions, the present invention uses the aerobic marine strain Mesophilic Adhesive Bacillus, which is well-known for producing highly adhesive biofilms. Mesophilic Adhesive Bacillus is a Gram-negative bacterium widely distributed in the marine environment, which has the potential functions of sustainable sources and anti-corrosion biopolymers, and shows excellent biofilm-forming ability among more than 30 tested species, and can form a stable and interconnected dense biofilm on the material surface.

[0030] 4. The present invention fixes the biofilm with glutaraldehyde, enhancing its adhesion to the surface of the material sample.

[0031] 5. The present invention performs a silanization treatment on the biofilm structure. Using n-octyltriethoxysilane, covalent silane grafting is carried out in-situ, generating a lipophilic and hydrophobic chemical layer with a strong affinity for lubricants, which is beneficial for further lubricant compounding. After injecting the lubricant silicone oil to wet it, a stable lubricant covering layer is thus formed, having good diffusion parameters, thereby generating a biofilm-derived smooth repellent coating in a highly synergistic manner, that is, a super-slippery anti-fouling coating with a highly adhesive biofilm structure, overcoming the non-uniformity between the repellency and mechanical properties of traditional coatings.

[0032] 6. The biofilm structure of the present invention has high cohesion, is derived from sustainable raw materials, and can be used as an inanimate biomaterial scaffold for forming super-slippery coating nano-scale textures without further processing.

[0033] 7. The preparation method of the super-slippery anti-fouling coating with a highly adhesive biofilm structure of the present invention is simple, easy to implement, environmentally friendly, and scalable. It customizes an innovative and sustainable biomaterial, endowing a strong, adhesive, and universal coating, capable of precisely adjusting the thickness of the biofilm structure framework at the nanoscale, thereby forming a stable and ultra-thin lubricant layer.

[0034] 8. The super-slippery anti-fouling coating with a highly adhesive biofilm structure of the present invention is an effective strategy for marine anti-fouling, having a universal super-slippery anti-fouling effect on corrosive media, proteins, bacteria, and algae, etc. It has stability and universality when used to prevent marine biofouling and corrosion, with a protein resistance of 72.3%, a bacteria resistance of 96.28%, and an algae resistance of 85.72%. It has excellent corrosion resistance, providing a new way for the development of efficient anti-fouling means in marine engineering and also being an effective application of engineered biofilms in practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a comparison diagram of the biofilm formation ability of Mesophilicadhaeribacter in Example 1 of the present invention and Shewanella oneidensis in Comparative Example 1 on 304 stainless steel;

[0036] Figure 2 It is an atomic force microscope (AFM) diagram showing the microstructure and roughness of the biofilm scaffold structure, hydrophobic-biofilm structure coating, and super-slippery anti-fouling coating with a highly adhesive biofilm structure of the 304 stainless steel sample in Example 1 of the present invention, where: (a) is the biofilm scaffold structure, (b) is the hydrophobic-biofilm structure coating, and (c) is the super-slippery anti-fouling coating with a highly adhesive biofilm structure;

[0037] Figure 3Fourier transform infrared spectroscopy (FTIR) diagrams of the biofilm support structure and the hydrophobic-biofilm structure coating of the 304 stainless steel sample in Example 1 of the present invention;

[0038] Figure 4 Transmission electron microscope (TEM) diagrams of the hydrophobic-biofilm structure coating in Example 1 of the present invention, where: (a) is the TEM dark field diagram and (b) is the TEM bright field diagram;

[0039] Figure 5 Energy dispersive spectroscopy (EDS) diagrams of the hydrophobic-biofilm structure coating in Example 1 of the present invention, where: (a) is the Si element, (b) is the O element, (c) is the C element, and (d) is the N element;

[0040] Figure 6 Transmittance of the blank glass measured by a UV spectrophotometer in the range of 400 nm - 800 nm, and the hydrophobic-biofilm structure coating and the highly adhesive biofilm structure super-slippery anti-fouling coating on the glass substrate in Example 6 of the present invention;

[0041] Figure 7 Water contact angle and water sliding angle of the highly adhesive biofilm structure super-slippery anti-fouling coating obtained by adopting the preparation method of Example 1 of the present invention and only changing the culture time for forming the biofilm structure of the sample in the bacterial culture solution;

[0042] Figure 8 Water contact angle and water sliding angle of the highly adhesive biofilm structure super-slippery anti-fouling coating prepared on different substrates in Examples 5 to 11 of the present invention;

[0043] Figure 9 Time-lapse snapshots of the sliding of 10 μL water droplets on the surface of the highly adhesive biofilm structure super-slippery anti-fouling coating on the 304 stainless steel substrate in Example 5 of the present invention and the surface of the blank group 304 stainless steel substrate, where: (a) is the photo of the blank group at t = 0.00 s, (b) is the photo of the blank group at t = 3.00 s, (c) is the photo of Example 5 at t = 0.00 s, and (d) is the photo of Example 5 at t = 5.00 s;

[0044] Figure 10 Time-lapse snapshots of the sliding of 10 μL water droplets on the surface of the highly adhesive biofilm structure super-slippery anti-fouling coating on the Teflon substrate in Example 7 of the present invention and the surface of the blank group Teflon substrate, where: (a) is the photo of the blank group at t = 0.00 s, (b) is the photo of the blank group at t = 2.00 s, (c) is the photo of Example 5 at t = 0.00 s, and (d) is the photo of Example 5 at t = 2.00 s;

[0045] Figure 11For the super-slippery anti-fouling coating with a highly adherent biofilm structure on the inner wall of the PVC pipe in Example 12 of the present invention and the sliding delay snapshot of a 10 μL water droplet on the inner wall of the blank group PVC pipe, where: (a) is the photo of the blank group at t = 0.00 s, (b) is the photo of the blank group at t = 3.00 s, (c) is the photo of the blank group at t = 6.00 s, (d) is the photo of Example 12 at t = 0.00 s, (e) is the photo of Example 12 at t = 2.00 s, and (f) is the photo of Example 12 at t = 4.00 s;

[0046] Figure 12 For the water sliding angles of the super-slippery anti-fouling coating with a highly adherent biofilm structure on the PET sheet in Example 8 of the present invention after being bent into U, V, and S shapes for 1000 bending cycles, where: (a) is the schematic diagram of the U-shaped bend, (b) is the schematic diagram of the V-shaped bend, (c) is the schematic diagram of the S-shaped bend, and (d) is the change diagram of the water sliding angle during the bending cycle;

[0047] Figure 13 For the electrochemical impedance spectra of the 304 stainless steel substrate with the super-slippery anti-fouling coating having a highly adherent biofilm structure in Example 1 of the present invention, the 304 stainless steel substrate with the super-slippery coating having a biofilm structure in Comparative Example 1, and the blank group 304 stainless steel substrate after being immersed in a Pseudomonas aeruginosa solution for 4 days;

[0048] Figure 14 For the comparative diagram of the changes in the colony counts of Escherichia coli, Staphylococcus aureus, and Bacillus vietnamensis measured by the dilution plating method for the hydrophobic-biofilm structure coating, the 304 stainless steel substrate with the super-slippery anti-fouling coating having a highly adherent biofilm structure, and the blank group 304 stainless steel substrate in Example 1 of the present invention;

[0049] Figure 15 For the comparative diagram of the algae resistance test results of the hydrophobic-biofilm structure coating, the 304 stainless steel substrate with the super-slippery anti-fouling coating having a highly adherent biofilm structure, and the blank group 304 stainless steel substrate against Chlorella vulgaris and Isochrysis galbana in Example 1 of the present invention. Detailed Embodiments

[0050] The technical solutions and technical effects of the present invention will be introduced in detail below in combination with specific embodiments and drawings. The experimental methods without specific conditions are usually carried out under conventional conditions, such as those described in textbooks and experimental guides, or according to the conditions recommended by the manufacturer, which are well-known or easily accessible to those of ordinary skill in the art. The following embodiments are only the preferred embodiments of the present invention and do not limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0051] Example 1

[0052] A preparation method of a super-slippery anti-fouling coating with a high-adhesion biofilm structure according to the present invention comprises the following steps:

[0053] Step 1: The single colony of Mesophilic Adhesive Bacillus isolated by the streak plate method is inoculated into 2216E liquid medium and cultured at 30 °C for 12 h until the logarithmic growth phase, and the bacterial concentration is adjusted to 10 6 CFU / mL to obtain a bacterial culture solution;

[0054] A 1 cm × 1 cm 304 stainless steel sample is surface-polished with 240, 400, 600, 800, and 1000-mesh sandpapers, then ultrasonically cleaned in a mixed solution of ethanol and acetone for 30 minutes, and then dried;

[0055] The 304 stainless steel sample is placed in the bacterial culture solution for culture. After 4 days of culture, a biofilm support structure of Mesophilic Adhesive Bacillus is conventionally formed on the surface of the 304 stainless steel sample.

[0056] Step 2: The 304 stainless steel sample covered with the biofilm support structure is gently rinsed with sterile PBS solution to remove floating Mesophilic Adhesive Bacillus, and fixed with 4% (v / v) glutaraldehyde for 2 h to obtain a biofilm 304 stainless steel sample substrate.

[0057] Step 3: The biofilm 304 stainless steel sample substrate is activated by oxygen plasma for 1 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0058] Step 4: The activated biofilm 304 stainless steel sample is subjected to dry (chemical vapor deposition) silanization treatment. The biofilm 304 stainless steel sample is placed in a vacuum dryer and chemically vapor deposited with 100 μL of n-octyltriethoxysilane at room temperature for 24 h. The silane undergoes in-situ hydrolysis and condensation reactions on the biofilm, thereby introducing a surface layer of repulsive silane on the biofilm, that is, a silane hydrophobic layer is formed on the surface of the biofilm structure of the 304 stainless steel sample, and a hydrophobic-biofilm structure coating of the 304 stainless steel sample is obtained.

[0059] Step 5: 20 μL of silicone oil is injected into the hydrophobic-biofilm structure coating of the 304 stainless steel sample, and an outer coating is formed by capillary force absorption. The inclination angle of the 304 stainless steel sample is adjusted to make the lubricant uniformly and fully cover the surface of the hydrophobic-biofilm structure coating of the 304 stainless steel sample, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is obtained.

[0060] Example 2

[0061] A preparation method of a super-slippery anti-fouling coating with a high-adhesion biofilm structure according to the present invention comprises the following steps:

[0062] Step 1: Inoculate a single colony of Mesophilic Adhesive Bacillus obtained by the streak plate method into 2216E liquid medium, culture at 30 °C for 12 h until the logarithmic growth phase, and adjust the bacterial concentration to 10 6 CFU / mL to obtain a bacterial culture solution;

[0063] Polish the surface of a 1 cm × 1 cm 304 stainless steel sample with 240, 400, 600, 800, and 1000 mesh sandpapers, then ultrasonically clean it in a mixed solution of ethanol and acetone for 30 minutes, and then dry it;

[0064] Place the 304 stainless steel sample into the bacterial culture solution for cultivation. After 3 days of cultivation, a biofilm scaffold structure of Mesophilic Adhesive Bacillus is conventionally formed on the surface of the 304 stainless steel sample.

[0065] Step 2: Gently rinse the 304 stainless steel sample covered with the biofilm scaffold structure with sterile PBS solution to remove floating Mesophilic Adhesive Bacillus, and fix it with 4% (v / v) glutaraldehyde for 2 h to obtain a biofilm 304 stainless steel sample substrate.

[0066] Step 3: Activate the biofilm 304 stainless steel sample substrate with oxygen plasma for 1 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0067] Step 4: Perform wet silanization treatment on the activated biofilm 304 stainless steel sample. Immerse the biofilm 304 stainless steel sample in an ethanol / water solution containing n-octyltriethoxysilane for 3 h. The volume ratio of n-octyltriethoxysilane to the ethanol / water solution is 1:1, so as to introduce a surface layer of repulsive silane on the biofilm, that is, form a silane hydrophobic layer on the surface of the biofilm structure of the 304 stainless steel sample, and obtain a hydrophobic-biofilm structure coating of the 304 stainless steel sample.

[0068] Step 5: Inject 20 μL of silicone oil into the hydrophobic-biofilm structure coating of the 304 stainless steel sample, absorb it by capillary force to form an outer coating, and adjust the tilt angle of the 304 stainless steel to make the lubricant evenly and fully cover the surface of the hydrophobic-biofilm structure coating of the 304 stainless steel, so as to obtain a super-slippery anti-fouling coating with a high-adhesion biofilm structure.

[0069] Example 3

[0070] The present invention provides a method for preparing a super-slippery anti-fouling coating with a high-adhesion biofilm structure, including the following steps:

[0071] Step 1: Inoculate the single colony of mesophilic adherent bacilli obtained by the streak plate method into 2216E liquid medium, culture at 30 °C for 12 h until the logarithmic growth phase, and adjust the bacterial concentration to 10 6 CFU / mL to obtain a bacterial culture solution;

[0072] Polish the surface of a 1 cm × 1 cm (supplementary sample size) 304 stainless steel sample with 240, 400, 600, 800, and 1000 - mesh sandpapers, then ultrasonically clean it in a mixed solution of ethanol and acetone for 30 minutes, and then dry it;

[0073] Place the 304 stainless steel sample into the bacterial culture solution for culturing. After 5 days of culturing, a biofilm scaffold structure of mesophilic adherent bacilli is routinely formed on the surface of the 304 stainless steel sample.

[0074] Step 2: Gently rinse the 304 stainless steel sample covered with the biofilm scaffold structure with sterile PBS solution to remove floating mesophilic adherent bacilli, and fix it with 4% (v / v) glutaraldehyde for 2 h to obtain a biofilm 304 stainless steel sample substrate.

[0075] Step 3: Activate the biofilm 304 stainless steel sample substrate with oxygen plasma for 2 min to remove the adsorbed water on the surface and generate more surface reactive groups.

[0076] Step 4: Perform wet silanization treatment on the activated biofilm 304 stainless steel sample. Immerse the biofilm 304 stainless steel sample in an ethanol / water solution containing n - octyltriethoxysilane for 4 h, and the volume ratio of n - octyltriethoxysilane to the ethanol / water solution is 1:1. Thus, a surface layer of repulsive silane is introduced onto the biofilm, that is, a silane hydrophobic layer is formed on the surface of the biofilm structure of the ceramic sample, and a hydrophobic - biofilm structure coating of the 304 stainless steel sample is obtained.

[0077] Step 5: Inject 20 μL of silicone oil into the hydrophobic - biofilm structure coating of the 304 stainless steel sample, and form an outer coating by capillary absorption. Adjust the tilt angle of the 304 stainless steel sample to make the lubricant evenly and fully cover the surface of the hydrophobic - biofilm coating of the ceramic sample, and obtain a super - slippery antifouling coating with a high - adhesion biofilm structure.

[0078] Example 4

[0079] The present invention provides a method for preparing a super - slippery antifouling coating with a high - adhesion biofilm structure, including the following steps:

[0080] Step 1: Inoculate the single colony of mesophilic adherent bacilli obtained by the streak plate method into 2216E liquid medium, culture at 30 °C for 12 h until the logarithmic growth phase, and adjust the bacterial concentration to 106 The bacterial culture solution was obtained at 10⁶ CFU / mL;

[0081] The surface of a 1 cm × 1 cm 304 stainless steel sample was polished with 240, 400, 600, 800, and 1000 - mesh sandpapers, then ultrasonically cleaned in a mixed solution of ethanol and acetone for 30 minutes, and then dried.

[0082] The 304 stainless steel sample was placed in the bacterial culture solution for cultivation. After 4 days of cultivation, a mesophilic adherent bacillus biofilm scaffold structure was conventionally formed on the surface of the 304 stainless steel sample.

[0083] Step 2: The 304 stainless steel sample covered with the biofilm scaffold structure was gently rinsed with a sterile PBS solution to remove floating mesophilic adherent bacilli, and fixed with 4% (v / v) glutaraldehyde for 2 h to obtain the biofilm - 304 stainless steel sample substrate.

[0084] Step 3: The biofilm - 304 stainless steel sample substrate was activated with oxygen plasma for 3 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0085] Step 4: The activated biofilm - 304 stainless steel sample was subjected to wet silanization treatment. The biofilm - 304 stainless steel sample was immersed in an ethanol / water solution containing n - octyltriethoxysilane for 6 h, and the volume ratio of n - octyltriethoxysilane to the ethanol / water solution was 1:1. Thus, a surface layer of repulsive silane was introduced onto the biofilm, that is, a silane hydrophobic layer was formed on the surface of the biofilm structure of the ceramic sample, and a hydrophobic - biofilm structure coating of the 304 stainless steel sample was obtained.

[0086] Step 5: 20 μL of silicone oil was injected into the hydrophobic - biofilm structure coating of the 304 stainless steel sample, and an outer coating was formed by capillary force absorption. The inclination angle of the 304 stainless steel sample was adjusted to make the lubricant uniformly and fully cover the surface of the hydrophobic - biofilm coating of the 304 stainless steel sample, and a super - slippery antifouling coating with a high - adhesion biofilm structure was obtained.

[0087] Example 5

[0088] The present invention provides a method for preparing a super - slippery antifouling coating with a high - adhesion biofilm structure, comprising the following steps:

[0089] Step 1: The single colony of mesophilic adherent bacilli obtained by the streak plate method was inoculated into 2216E liquid medium and cultured at 30 °C for 12 h until the logarithmic growth phase, and the bacterial concentration was adjusted to 10 8 CFU / mL to obtain the bacterial culture solution;

[0090] A 7.62 cm × 2.54 cm 304 stainless steel sample was surface polished with 240, 400, 600, 800, and 1000 - mesh sandpapers, then ultrasonically cleaned in a mixed solution of ethanol and acetone for 30 minutes, and then dried.

[0091] The 304 stainless steel sample was placed in a bacterial culture medium and cultured. After 4 days, a mesophilic adhesive bacillus biofilm scaffold structure was conventionally formed on the surface of the 304 stainless steel sample.

[0092] Step 2: The 304 stainless steel sample covered with the biofilm scaffold structure was gently rinsed with a sterile PBS solution to remove planktonic mesophilic adhesive bacilli, and fixed with 2% (v / v) glutaraldehyde for 8 h to obtain a biofilm 304 stainless steel sample substrate.

[0093] Step 3: The biofilm 304 stainless steel sample substrate was activated with oxygen plasma for 5 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0094] Step 4: The activated biofilm 304 stainless steel sample was subjected to dry (chemical vapor deposition) silanization treatment. The biofilm 304 stainless steel sample was placed in a vacuum desiccator and treated with 100 μL of n - octyltriethoxysilane by chemical vapor deposition at room temperature for 36 h. The silane underwent in - situ hydrolysis and condensation reactions on the biofilm, thereby introducing a surface layer of repulsive silane on the biofilm, that is, a silane hydrophobic layer was formed on the surface of the biofilm structure of the 304 stainless steel sample, and a hydrophobic - biofilm structure coating of the 304 stainless steel sample was obtained.

[0095] Step 5: 400 μL of silicone oil was injected into the hydrophobic - biofilm structure coating of the 304 stainless steel sample, and an outer coating was formed by capillary force absorption. The inclination angle of the 304 stainless steel sample was adjusted to make the lubricant uniformly and fully cover the surface of the hydrophobic - biofilm coating of the 304 stainless steel sample, and a super - slippery antifouling coating with a high - adhesion biofilm structure was obtained.

[0096] Example 6

[0097] The present invention provides a method for preparing a super - slippery antifouling coating with a high - adhesion biofilm structure, including the following steps:

[0098] Step 1: The mesophilic adhesive bacillus single colonies obtained by the streak plate method were inoculated into 2216E liquid medium and cultured at 30 °C for 12 h until the logarithmic growth phase, and the bacterial concentration was adjusted to 10 5 CFU / mL to obtain a bacterial culture solution;

[0099] A 7.62 cm × 2.54 cm glass sample was ultrasonically cleaned in a mixed solution of ethanol and acetone for 30 minutes, and then dried.

[0100] The glass sample is placed in a bacterial culture medium and cultured. After 4 days of culture, a mesophilic adherent bacillus biofilm scaffold structure is routinely formed on the surface of the glass sample.

[0101] Step 2: The glass sample covered with the biofilm scaffold structure is gently rinsed with a sterile PBS solution to remove floating mesophilic adherent bacilli, and fixed with 3% (v / v) glutaraldehyde for 4 h to obtain a biofilm glass sample substrate.

[0102] Step 3: The biofilm glass sample substrate is activated with oxygen plasma for 5 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0103] Step 4: The activated biofilm glass sample is subjected to dry (chemical vapor deposition) silanization treatment. The biofilm glass sample is placed in a vacuum dryer and chemically vapor deposited with 100 μL of n-octyltriethoxysilane at room temperature for 12 h. The silane undergoes in-situ hydrolysis and condensation reactions on the biofilm, thereby introducing a surface layer of repulsive silane on the biofilm, that is, a silane hydrophobic layer is formed on the surface of the biofilm structure of the glass sample, and a hydrophobic-biofilm structure coating of the glass sample is obtained.

[0104] Step 5: 400 μL of silicone oil is injected into the hydrophobic-biofilm structure coating of the glass sample, and an outer coating is formed by capillary force absorption. The tilt angle of the glass sample is adjusted to make the lubricant uniformly and fully cover the surface of the hydrophobic-biofilm coating of the glass sample, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is obtained.

[0105] Example 7

[0106] The present invention provides a method for preparing a super-slippery anti-fouling coating with a high-adhesion biofilm structure, comprising the following steps:

[0107] Step 1: The single colony of mesophilic adherent bacilli obtained by the streak plate method is inoculated into a 2216E liquid medium and cultured at 30 °C for 12 h until the logarithmic growth phase, and the bacterial concentration is adjusted to 10 8 CFU / mL to obtain a bacterial culture solution;

[0108] The 7.62 cm × 2.54 cm Teflon is ultrasonically cleaned in a mixed solution of ethanol and acetone for 30 minutes and then dried.

[0109] The Teflon sample is placed in a bacterial culture medium and cultured. After 4 days of culture, a mesophilic adherent bacillus biofilm scaffold structure is routinely formed on the surface of the Teflon sample.

[0110] Step 2: Gently rinse the Teflon sample covering the biofilm scaffold structure with sterile PBS solution to remove planktonic Mesophilic adherent bacilli, and fix it with 2% (v / v) glutaraldehyde for 8 h to obtain the biofilm Teflon sample substrate.

[0111] Step 3: Activate the biofilm Teflon sample substrate with oxygen plasma for 5 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0112] Step 4: Perform dry (chemical vapor deposition) silanization on the activated biofilm Teflon sample. Place the biofilm Teflon sample in a vacuum desiccator and perform chemical vapor deposition treatment with 100 μL of n-octyltriethoxysilane at room temperature for 36 h. The silane undergoes in-situ hydrolysis and condensation reactions on the biofilm, thereby introducing a surface layer of repulsive silane on the biofilm, that is, forming a silane hydrophobic layer on the surface of the biofilm structure of the Teflon sample to obtain a hydrophobic-biofilm structure coating of the Teflon sample.

[0113] Step 5: Inject 400 μL of silicone oil into the hydrophobic-biofilm structure coating of the Teflon sample, and form an outer coating by capillary force absorption. Adjust the tilt angle of the Teflon sample to make the lubricant evenly and fully cover the surface of the hydrophobic-biofilm coating of the Teflon sample to obtain a super-slippery antifouling coating with a highly adherent biofilm structure.

[0114] Example 8

[0115] The present invention provides a method for preparing a super-slippery antifouling coating with a highly adherent biofilm structure, comprising the following steps:

[0116] Step 1: Inoculate the single colony of Mesophilic adherent bacilli separated by the streak plate method into 2216E liquid medium and culture it at 30 °C for 12 h until the logarithmic growth phase, and adjust the bacterial concentration to 10 8 CFU / mL to obtain a bacterial culture solution;

[0117] Ultrasonically clean a 7.62 cm × 2.54 cm polyethylene terephthalate (PET) sample in a mixed solution of ethanol and acetone for 30 minutes, and then dry it.

[0118] Place the PET sample into the bacterial culture solution for culture. After 4 days of culture, a biofilm scaffold structure of Mesophilic adherent bacilli is routinely formed on the surface of the PET sample.

[0119] Step 2: Gently rinse the PET sample covering the biofilm scaffold structure with sterile PBS solution to remove planktonic Mesophilic adherent bacilli, and fix it with 2% (v / v) glutaraldehyde for 8 h to obtain the biofilm PET sample substrate.

[0120] Step 3: Activate the biofilm PET sample substrate with oxygen plasma for 5 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0121] Step 4: Perform dry (chemical vapor deposition) silanization on the activated biofilm PET sample. Place the biofilm PET sample in a vacuum desiccator and perform chemical vapor deposition treatment with 100 μL of n-octyltriethoxysilane at room temperature for 36 h. The silane undergoes in-situ hydrolysis and condensation reactions on the biofilm, thereby introducing a surface layer of repulsive silane on the biofilm, that is, forming a silane hydrophobic layer on the surface of the biofilm structure of the PET sample, and obtaining a hydrophobic-biofilm structure coating for the PET sample.

[0122] Step 5: Inject 400 μL of silicone oil into the hydrophobic-biofilm structure coating of the PET sample, and form an outer coating by capillary force absorption. Adjust the tilt angle of the PET sample to make the lubricant evenly and fully cover the surface of the hydrophobic-biofilm coating of the Teflon sample, and obtain a super-slippery anti-fouling coating with a high-adhesion biofilm structure.

[0123] Example 9

[0124] The difference from Example 5 is only that the sample substrate is Ti, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is prepared on the Ti sample.

[0125] Example 10

[0126] The difference from Example 5 is only that the sample substrate is Al, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is prepared on the Al sample.

[0127] Example 11

[0128] The difference from Example 5 is only that the sample substrate is 2205 stainless steel, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is prepared on the 2205 stainless steel sample.

[0129] Example 12

[0130] The difference from Example 8 is only that the sample substrate is a polyvinyl chloride (PVC) pipe with an inner diameter of 3 mm. The PVC pipe is immersed in a bacterial liquid culture medium for cultivation, and a super-slippery anti-fouling coating with a high-adhesion biofilm structure is prepared on the inner wall of the narrow-hole PVC pipe.

[0131] Comparative Example 1

[0132] Replace the mesophilic adhesive bacillus in Example 1 with Shewanella oneidensis, and observe the formation of the biofilm scaffold structure of Shewanella oneidensis.

[0133] Step 1: Use the streak plate method to isolate single colonies of Shewanella oneidensis and inoculate them into 2216E liquid medium. Incubate at 30 °C for 12 h until the logarithmic growth phase, and adjust the bacterial concentration to 10 6 CFU / mL to obtain a bacterial culture solution;

[0134] Polish the surface of a 1 cm × 1 cm 304 stainless steel sample with 240, 400, 600, 800, and 1000 mesh sandpapers, then ultrasonically clean it in a mixed solution of ethanol and acetone for 30 minutes, and then dry it;

[0135] Place the 304 stainless steel sample in the bacterial culture solution for cultivation. After 4 days of cultivation, a Shewanella oneidensis biofilm scaffold structure is formed on the surface of the 304 stainless steel sample.

[0136] Step 2: Gently rinse the 304 stainless steel sample covered with the biofilm scaffold structure with sterile PBS solution to remove floating Shewanella oneidensis, and fix it with 4% (v / v) glutaraldehyde for 2 h to obtain a biofilm 304 stainless steel sample substrate.

[0137] Step 3: Activate the biofilm 304 stainless steel sample substrate with oxygen plasma for 1 min to remove adsorbed water on the surface and generate more surface reactive groups.

[0138] Step 4: Perform dry (chemical vapor deposition) silanization treatment on the activated biofilm 304 stainless steel sample. Place the biofilm 304 stainless steel sample in a vacuum dryer and perform chemical vapor deposition treatment with 100 μL of octyltriethoxysilane at room temperature for 24 h. The silane undergoes in-situ hydrolysis and condensation reactions on the biofilm, thereby introducing a repulsive silane surface layer on the biofilm, that is, forming a silane hydrophobic layer on the surface of the biofilm structure of the 304 stainless steel sample to obtain a hydrophobic-biofilm structure coating for the 304 stainless steel sample.

[0139] Step 5: Inject 20 μL of silicone oil into the hydrophobic-biofilm structure coating of the 304 stainless steel sample, and form an outer coating by capillary force absorption. Adjust the tilt angle of the 304 stainless steel sample to make the lubricant evenly and fully cover the surface of the hydrophobic-biofilm structure coating of the 304 stainless steel sample to obtain a super-slippery coating of the biofilm structure.

[0140] Performance analysis

[0141] 1. Analysis of the physical and chemical properties of the coating:

[0142] 1.1 Analysis of the coating thickness:

[0143] Four groups of identical 304 stainless steel samples were respectively placed in the bacterial culture solution of Mesophilic Adhesive Bacillus in Example 1 and the bacterial culture solution of Shewanella oneidensis in Comparative Example 1. After culturing for 1 day, 4 days, 7 days, and 14 days, the same solidification operation was carried out to obtain biofilm 304 stainless steel samples. Then, the biofilm 304 stainless steel samples were subjected to crystal violet staining, and the biofilm formation abilities of the bacteria Mesophilic Adhesive Bacillus and Shewanella oneidensis were compared through the crystal violet staining results of different culture days; as Figure 1 shown, an enzyme-linked immunosorbent assay (ELISA) reader was used to measure the absorbance value at OD 570nm . It can be seen that the absorbance value of the biofilm of Mesophilic Adhesive Bacillus reached twice that of the biofilm structure of Shewanella oneidensis after 4 days of culture. After 14 days of culture, the absorbance value of Mesophilic Adhesive Bacillus was 7 times that of Shewanella oneidensis, indicating that the bacteria selected in the present invention have stronger film-forming ability and are more conducive to the construction of the structural scaffold.

[0144] 1.2 Analysis of coating surface morphology:

[0145] An atomic force microscope (AFM) was used to observe the surface structure and roughness of the biofilm scaffold structure, hydrophobic-biofilm structure coating, and super-slippery antifouling coating with high-adhesion biofilm structure on the 304 stainless steel samples in Example 1. As Figure 2 shown, depositing a silane monolayer produced a highly integrated biofilm skeleton with enhanced root mean square roughness (RMS). The roughness of the super-slippery antifouling coating with high-adhesion biofilm structure was 15.05 nm, lower than that of the biofilm structure (38.2 nm) and the hydrophobic-biofilm structure coating (46.92 nm). This is because the lubricant filled the unevenness on the surface of the hydrophobic-biofilm structure coating, giving it super-slippery performance.

[0146] 1.3 Analysis of coating chemical structure:

[0147] As Figure 3 shown, Fourier transform infrared spectroscopy (FTIR) was used to show the evolution process of covalent grafting of the hydrophobic-biofilm structure coating in Example 1. It was found that a new characteristic peak appeared at 1017 cm -1 for the asymmetric stretching vibration of Si-O. A broad characteristic peak between 3100 cm -1 - 3700 cm -1 was attributed to the overlap of the O-H stretching vibration of polysaccharides and the N-H stretching vibration of proteins. The results showed that more chemical reaction sites were generated on the surface of the hydrophobic-biofilm structure coating, which was beneficial for subsequent surface modification.

[0148] 1.4 Analysis of coating element distribution:

[0149] As Figure 4As shown, from the structural observations of transmission electron microscopy (TEM) and high-angle annular dark-field scanning TEM images, it can be seen that after silane functionalization, the typical rod-like morphology is retained on the surface of the biological scaffold structure, such as Figure 5 As shown, the corresponding energy-dispersive spectroscopy (EDS) map indicates that the distributions of C, N, and O are uniform, and the enhanced distribution of Si elements is consistent with the bacterial contour, verifying the successful binding of Si elements on the coating surface.

[0150] 1.5 Analysis of coating light transmittance:

[0151] Due to the universality of the adhesion of mesophilic adherent bacteria, the super-slippery antifouling coating with a highly adherent biofilm structure in Example 6 of the present invention is also suitable for being fabricated on a transparent substrate glass, such as Figure 6 As shown, the optical properties of the blank glass, the hydrophobic-biofilm structure coating on the transparent substrate glass, and the super-slippery antifouling coating with a highly adherent biofilm structure were compared by the light transmittance in the visible light range of 400 nm - 800 nm. Compared with the blank glass with a light transmittance of 90.0%, the light transmittance of the hydrophobic-biofilm structure coating on the transparent substrate glass was slightly reduced to 79.1%. However, due to the smooth morphology of the super-slippery antifouling coating with a highly adherent biofilm structure, its light transmittance was close to that of the blank glass at 89.4%. Therefore, the influence of the super-slippery antifouling coating with a highly adherent biofilm structure of the present invention on transparency can be ignored.

[0152] 2. Analysis of coating hydrophobic properties:

[0153] 2.1 Wettability analysis:

[0154] By measuring the water contact angle and sliding angle on the surface of the super-slippery antifouling coating with a highly adherent biofilm structure, as well as the sliding angle on samples of different shapes, the sliding effect of water droplets on the coating surface was measured;

[0155] A contact angle measuring instrument was used to measure the contact angle of pure water (the contact angle of a 4 μL water droplet) and the sliding angle (the inclination angle required for the movement of a 6 μL water droplet) to evaluate the surface wettability of the coating at different biofilm culture days;

[0156] According to the preparation method of the super-slippery antifouling coating with a highly adherent biofilm structure in Example 1, only the culture time of the 304 stainless steel sample in the bacterial culture medium was changed. After grouping and culturing for 1 day, 4 days, 7 days, and 14 days, the droplet migration rate of the prepared super-slippery antifouling coating with a highly adherent biofilm structure was observed. Each group of super-slippery antifouling coatings with a highly adherent biofilm structure was composed of biofilm nano-textures, such as Figure 7As shown, the biofilm with a short cultivation time (1 day) has a thin and incomplete framework, resulting in an unstable lubricating layer. Although the lubricant can maintain a stable wet form, its liquid repellency is poor. By extending the cultivation time of the biofilm nanostructure on the 304 stainless steel sample, a thicker biofilm (such as 7 days or 14 days) exhibits a higher surface roughness, and the liquid droplet enters the Wenzel state with a pinning effect. The water contact angle of the super-slippery anti-fouling coating with a highly adhesive biofilm structure cultivated for 4 days is 104.3 ° and the water sliding angle is 1.8 ° , providing excellent slipperiness as the critical point of surface level change. Therefore, cultivating for 4 days is the preferred option for the biofilm structure on the 304 stainless steel substrate.

[0157] 2.2 Universal analysis of material substrates:

[0158] Examples 5 to 11 are respectively the preparation of super-slippery anti-fouling coatings with highly adhesive biofilm structures on different substrates. At an inclination angle of 25 ° , through a contact angle measuring instrument, the contact angle of pure water (the contact angle of a 4 μL water droplet) and the sliding angle (the inclination angle required for the movement of a 6 μL water droplet) are measured to explore the sliding effect of the liquid droplet on the super-slippery anti-fouling coating with a highly adhesive biofilm structure prepared on different substrates. As Figure 8 shown, after preparing the super-slippery anti-fouling coating with a highly adhesive biofilm structure on Ti, Al, 304 stainless steel, 2205 stainless steel, Teflon, and PET samples, the water sliding angle is all lower than 5 ° . This is due to the biofilm support structure with strong interfacial anchoring ability and high cohesion. Therefore, the super-slippery anti-fouling coating with a highly adhesive biofilm structure can be evenly attached to various metal, inorganic, and organic substrates and endow them with hydrophobic (liquid-repellent) properties, which strongly proves the universal applicability of the super-slippery anti-fouling coating with a highly adhesive biofilm structure of the present invention to various material types.

[0159] For the super-slippery anti-fouling coatings with highly adhesive biofilm structures on 304 stainless steel samples and Teflon samples in Examples 5 and 7, at an inclination angle of 25 ° , as Figure 9 , Figure 10 shown, it is observed that the water droplets marked with dye slide effortlessly along the substrates of the super-slippery anti-fouling coating with a highly adhesive biofilm structure on the incline without leaving any residue. In contrast, the bare substrates, even on the low surface energy material Teflon, will be completely wetted and contaminated by water, indicating that the super-slippery anti-fouling coating with a highly adhesive biofilm structure of the present invention has excellent hydrophobic properties.

[0160] The manufacturing method of the biofilm of the present invention is easy to implement and is suitable for generating a uniform antifouling coating on the inner surface. In Example 12, a super-slippery antifouling coating with a high-adhesion biofilm structure was prepared on the inner wall of a PVC pipe with an inner diameter of 3 mm, as Figure 11 shown. 10 μL of dyed water was placed at the open end of the PVC pipe with the super-slippery antifouling coating with a high-adhesion biofilm structure. The water droplet could easily pass through the inner wall of the pipe without being dyed. In contrast, the blank group of PVC pipes showed that the liquid easily adhered to their inner walls, which also indicated that the super-slippery antifouling coating with a high-adhesion biofilm structure of the present invention also has shape universality.

[0161] 2.3 Analysis of coating bending resistance:

[0162] In Example 8, a super-slippery antifouling coating with a high-adhesion biofilm structure was prepared on a PET substrate with a size of 7.62 cm × 2.54 cm and bent into U, V, and S shapes. The sliding angle was measured after 1000 times of repeated bending and releasing;

[0163] As Figure 12 shown, the bending test results of the super-slippery antifouling coating with a high-adhesion biofilm structure prepared on a flexible PET sheet are shown. The super-slippery antifouling coating with a high-adhesion biofilm structure on the PET sheet can be successively folded into different shapes. During the bending process and after recovery, no delamination or damage was observed on the coating. Even more than 1000 twists and multiple folds failed to prevent the sliding behavior of the super-slippery antifouling coating with a high-adhesion biofilm structure, which indicated that our coating has excellent bending resistance.

[0164] 3. Analysis of coating anti-corrosion performance:

[0165] Electrochemical tests were carried out using a three-electrode device containing 250 mL of solution at 30 °C. The corrosive Pseudomonas aeruginosa was selected as the experimental strain, and a saturated calomel electrode, a platinum sheet electrode, and a coating electrode were selected as the reference electrode, the counter electrode, and the working electrode respectively. Electrochemical impedance spectroscopy (EIS) data were obtained in the frequency range of 10 5 Hz to 10 -2 Hz with an amplitude of 5 mV;

[0166] 3.1 Effective physical barrier:

[0167] Mesophilic adhesive bacilli play a crucial role in corrosion protection due to their strong biofilm-forming ability; cohesive EPS is the main component of biofilms, which can firmly adhere to natural metal surfaces or oxide layers through strong and stable secondary chemical bonds, electrostatic interactions, hydrogen bonds, and van der Waals interactions, including hydrophobic forces; as determined by the component analysis of extracellular polymers, this continuously produced dense biopolymer matrix provides a physical barrier at the metal-coating interface in highly cohesive biofilms, effectively shielding corrosive substances such as oxygen and chloride ions;

[0168] 3.2 Electrochemical tests:

[0169] The blank group of 304 stainless steel substrates, the super-slippery coating 304 stainless steel substrates with the biofilm structure of Shewanella oneidensis in Comparative Example 1, and the super-slippery antifouling coating 304 stainless steel substrates with the high-adhesion biofilm structure in Example 1 were immersed in simulated seawater containing corrosive Pseudomonas aeruginosa for 4 days. The corrosion protection performance was tested by electrochemical measurement, and the results were analyzed by electrochemical impedance spectroscopy (EIS) to study the influence of the high-adhesion biofilm structure design of mesophilic adhesive bacilli in the present invention on the corrosion protection of substrates.

[0170] As Figure 13 shown, according to the electrochemical impedance spectroscopy diagram, compared with the super-slippery coating 304 stainless steel substrates with the biofilm structure of Shewanella oneidensis in Comparative Example 1, the capacitance loop diameter of the super-slippery antifouling coating 304 stainless steel substrates with the high-adhesion biofilm structure of mesophilic adhesive bacilli in Example 1 is much larger than that of the blank group of 304 stainless steel substrates. This indicates that the formation of a compact biofilm structure of mesophilic adhesive bacilli increases the charge transfer resistance. The pre-fixed dead biofilm formed by glutaraldehyde does not provide continuous metabolic activity and also shows significant corrosion inhibition, confirming that this anti-corrosion ability is mainly attributed to extracellular polymers (EPS) rather than cell viability.

[0171] 4. Analysis of the antifouling performance of the coating:

[0172] Stages of biofouling occurrence: protein adhesion (conditioning film stage); bacterial adhesion (unstable biofilm stage); algal adhesion (colonized biofilm stage).

[0173] Stages of the formation of the biofouling layer on the solid surface of the seabed: First, any object invading seawater will adsorb a layer of organic matter, mainly proteins and polysaccharides, on the surface within a few minutes. Then, bacteria and algae will successively attach to the whole film, secrete extracellular metabolites to form a biofilm, and the larvae of fungi and large fouling organisms will grow and develop within the film, and finally form a complex large fouling organism layer. The super-slippery antifouling coating with a high-adhesion biofilm structure acts as a smooth surface to prevent the stable attachment of fouling organisms and provides a more controllable and stable surface by regulating the interfacial tension and the solubility of the liquid in water. In this study, bovine serum albumin (BSA), Gram-positive Staphylococcus aureus, Bacillus vietnamensis, Gram-negative Escherichia coli, which are common in marine environments and daily life environments, and Chlorella vulgaris and Isochrysis galbana, which are widely distributed in the ocean, were used for exploration.

[0174] 4.1 Protein resistance:

[0175] The anti-protein performance was quantified using an adsorption test, in which a higher concentration of BSA with 2 mg / mL - 4 mg / mL was applied and incubated for 24 h. The proteins firmly bound to the sample were extracted by vigorously rinsing with sterile water, and the relative amount of BSA adhered to the surface was quantified by measuring the absorbance of the collected washing solution at λ = 280 nm.

[0176] The hydrophobic-biofilm structure coating, the super-slippery antifouling coating with a high-adhesion biofilm structure, and the 304 stainless steel samples of the blank group in Example 1 were respectively immersed in the BSA solution for 24 hours, and the adsorption amount on the sample surface was quantitatively analyzed. The residual BSA on the 304 stainless steel samples of the hydrophobic-biofilm structure coating and the super-slippery antifouling coating with a high-adhesion biofilm structure was only 0.45 ± 0.002 mg·cm -2 、0.23 ± 0.05 mg·cm -2 while the residual BSA on the bare 304 stainless steel sample was as high as 0.83 ± 0.05 mg·cm -2 This indicates that the lubricating layer reduces the contact and adsorption of proteins on the surface, proving that the super-slippery antifouling coating with a high-adhesion biofilm structure has excellent anti-protein performance. The anti-protein performance of the super-slippery antifouling coating with a high-adhesion biofilm structure of the present invention reaches 72.3%. The formula for calculating the protein resistance is as follows:

[0177] Protein resistance = (BSA 空白组 - BSA 实验组 ) / BSA 空白组 × 100%

[0178] 4.2 Bacterial resistance:

[0179] During the process of marine pollution, bacteria play a crucial role in the construction of biofilms. Using Escherichia coli (Gram-negative bacterium), Staphylococcus aureus, and Bacillus vietnamensis (Gram-positive bacterium) as model bacteria, the antibacterial properties of the super-slippery antifouling coating with a highly adhesive biofilm structure of the present invention were investigated. For the antibacterial evaluation, all materials were sterilized by ultraviolet irradiation for 30 minutes before use. The single bacterial colonies of Escherichia coli, Staphylococcus aureus, and Bacillus vietnamensis isolated by the streak plate method were respectively inoculated into 2216E or Luria-Bertani liquid medium and cultured at 37°C for 12 h - 16 h until the logarithmic growth phase. The bacterial suspension in the logarithmic growth phase was diluted to obtain a bacterial suspension with an appropriate concentration for subsequent experiments.

[0180] Add 2 ml of the Escherichia coli bacterial suspension to a 24-well culture plate. After culturing the hydrophobic-biofilm structure coating, the super-slippery antifouling coating with a highly adhesive biofilm structure on 304 stainless steel samples, and the blank group of 304 stainless steel samples in Example 1 at 37°C for 1 day, gently rinse with sterile PBS solution to remove the loosely adhered bacteria on the surface. The antibacterial ability of the samples was quantitatively studied by the dilution coating plate method. The bacteria on the biofilm on the surface were collected, serially diluted in sterile PBS solution (pH = 7.3), then plated on agar plates, and after culturing at 37°C for 10 h, the colonies on the plates were photographed and counted.

[0181] Add a certain amount of Staphylococcus aureus bacterial suspension to a 24-well culture plate. After culturing the hydrophobic-biofilm structure coating, the super-slippery antifouling coating with a highly adhesive biofilm structure on 304 stainless steel samples, and the blank group of 304 stainless steel samples in Example 1 at 37°C for 1 day, gently rinse with sterile PBS solution to remove the loosely adhered bacteria on the surface. The antibacterial ability of the samples was quantitatively studied by the dilution coating plate method. The bacteria on the biofilm on the surface were collected, serially diluted in sterile PBS solution (pH = 7.3), then plated on agar plates, and after culturing at 37°C for 14 h, the colonies on the plates were photographed and counted.

[0182] Add a certain amount of Bacillus vietnamensis bacterial suspension to a 24-well culture plate. After culturing the hydrophobic-biofilm structure coating, the super-slippery antifouling coating with a highly adhesive biofilm structure on 304 stainless steel samples, and the blank group of 304 stainless steel samples in Example 1 at 37°C for 1 day, gently rinse with sterile PBS solution to remove the loosely adhered bacteria on the surface. The antibacterial ability of the samples was quantitatively studied by the dilution coating plate method. The bacteria on the biofilm on the surface were collected, serially diluted in sterile PBS solution (pH = 7.3), then plated on agar plates, and after culturing at 37°C for 10 h, the colonies on the plates were photographed and counted.

[0183] The viable bacteria were quantified using the dilution plating method to evaluate the antibacterial properties of different coatings. As Figure 14 shown, compared with the blank group, in the biofilm of the hydrophobic-biofilm structure coating sample, the percentage of viable cells in the biofilms of Escherichia coli, Staphylococcus aureus, and Bacillus vietnamensis did not significantly decrease. However, compared with the blank group, the colony-forming unit (CFU) counts of the super-slippery antifouling coating with a high-adhesion biofilm structure in the biofilms of Escherichia coli, Staphylococcus aureus, and Bacillus vietnamensis decreased by 2.0 log, 1.1 log, and 2.0 log, respectively. The super-slippery antifouling coating with a high-adhesion biofilm structure of the present invention has a bacterial resistance of 96.28%. The formula for calculating bacterial resistance is as follows:

[0184] Bacterial resistance = (CFU 空白组 -CFU 实验组 ) / CFU 空白组 × 100%

[0185] 4.3 Algal resistance:

[0186] Algae are also one of the main causes in the second stage of the marine biofouling process. The anti-algal properties of the super-slippery antifouling coating with a high-adhesion biofilm structure were tested using Chlorella vulgaris and Isochrysis galbana.

[0187] Before the experiment, all experimental supplies such as the culture medium and pipettes required for co-culture were sterilized by ultraviolet light for 30 minutes. Two different algal strains, Chlorella vulgaris and Isochrysis galbana, were used as experimental microalgae species. The two microalgae were cultured in F / 2 medium respectively, under visible light (LED) illumination (3000 lux) at 20 °C for 8 days. The algal solution in the logarithmic growth phase was diluted with the culture medium to obtain an appropriate concentration (10 5 cells·mL -1 ) for subsequent experiments. The hydrophobic-biofilm structure coating, the super-slippery antifouling coating with a high-adhesion biofilm structure on 304 stainless steel samples, and the blank group of 304 stainless steel samples in Example 1 were immersed in these diluted algal suspensions for 7 days under a light cycle of sunlight and darkness, and then thoroughly rinsed with sterile PBS solution (pH = 7.3) to remove loosely attached algae. The anti-algal ability of the super-slippery antifouling coating with a high-adhesion biofilm structure was studied by measuring the absorbance at λ = 440 nm, and the absorbance represents the algal biomass.

[0188] As Figure 15As shown, it can be seen that during the growth process, according to the characteristic absorption signal, the difference in algal settlement between the test surfaces is significant. The algal coverage rate of the super-slippery antifouling coating with a high-adhesion biofilm structure is relatively low. The anti-algal mechanism of the super-slippery antifouling coating with a high-adhesion biofilm structure is similar to the antibacterial mechanism and is related to the physical barrier of the lubricant. The super-slippery antifouling coating with a high-adhesion biofilm structure of the present invention has an algal resistance of 85.72%. The algal resistance calculation formula is as follows:

[0189] Algal resistance = (absorbance 空白组 - absorbance 实验组 ) / absorbance 实验组 × 100%.

Claims

1. A method for preparing an ultra-slip antifouling coating with a high-adhesion biofilm structure, characterized in that: The steps include: Step 1: Cultivate the mesophilic mycobacterium and adjust the bacterial concentration to 10 5 CFU / mL-10 8 CFU / mL, obtain bacterial culture solution, place the material sample in the bacterial culture solution for culture, and cover the surface of the material sample with a biofilm support structure; the material sample includes metal, glass and polymer, the metal sample is surface polished, cleaned and dried before being placed in the bacterial culture solution, and the glass and polymer are cleaned and dried before being placed in the bacterial culture solution; the material sample is placed in the bacterial culture solution for 3-5 days; Step 2: The material sample covering the biofilm scaffold structure is appropriately rinsed aseptically to remove floating bacteria, and fixed with glutaraldehyde to obtain a biofilm material sample base; Step 3: Activate the biofilm material sample substrate to eliminate surface adsorbed water and generate more surface reactive groups; Step 4: dry or wet silanization treatment is performed on the activated biofilm material sample substrate to deposit hydrophobic silane on the biofilm structure surface of the material sample to obtain a hydrophobic-biofilm structure coating of the material sample; dry silanization treatment is to place the biofilm material sample in a vacuum desiccator and perform chemical vapor deposition treatment with n-octyltriethoxysilane at room temperature; wet silanization treatment is to immerse the biofilm material sample in an ethanol / water solution containing n-octyltriethoxysilane; Step 5: Inject the lubricant into the hydrophobic-biofilm structure coating of the material sample, absorb it through capillary force to form an outer coating, adjust the inclination angle of the material sample so that the lubricant is evenly and fully covered on the surface of the hydrophobic-biofilm structure coating of the material sample, and obtain an ultra-slip anti-fouling coating with a high adhesion biofilm structure.

2. The method for preparing a super-slip antifouling coating with a high-adhesion biofilm structure according to claim 1, characterized in that: In step 1, the mesophilic adhesin Bacillus is cultured by inoculating the separated single colony of the mesophilic adhesin Bacillus into 2216E liquid culture medium using a plate streak method, the culture temperature is 20° C.-40° C., and the culture is carried out until it is in the logarithmic growth phase.

3. The method for preparing a super-slip antifouling coating with a high-adhesion biofilm structure according to claim 1, characterized in that: In step 2, sterile phosphate buffer is used for sterile flushing; The concentration of glutaraldehyde in glutaraldehyde fixation is 2%-6% (v / v), and the fixation time is 2h-8h.

4. The method for preparing a super-slip antifouling coating with a high-adhesion biofilm structure according to claim 1, characterized in that: In step 3, activation is performed by oxygen plasma treatment for 1 min to 5 min.

5. The method for preparing a super-slip antifouling coating with a high-adhesion biofilm structure according to claim 1, characterized in that: In step 4, in the dry silanization treatment, octyltriethoxysilane is used for chemical vapor deposition treatment for 12h-36h; The volume ratio of n-octyltriethoxysilane to ethanol / water solution in wet silanization treatment is 1:1, and the immersion time is 3h-6h.

6. The method for preparing a super-slip antifouling coating with a high-adhesion biofilm structure according to claim 1, characterized in that: In step 5, the lubricant is silicone oil.

7. An ultra-slip antifouling coating with a high-adhesion biofilm structure, characterized in that: The method for preparing an ultra-slip antifouling coating with a high-adhesion biofilm structure as described in any one of claims 1 to 6 is used for preparation. The ultra-slip antifouling coating is a porous surface of an anti-corrosion biofilm structure injected with a smooth liquid, uses the biofilm as a support structure, has a nanoscale texture, deposits hydrophobic silane on the surface of the biofilm structure, and is compounded with a lubricant.

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