A biomimetic antifouling coating for complex environments

Abstract

The present application provides a kind of bionic antifouling coating for complex environment.The bionic antifouling coating has at least one of a conical needle array surface, a rib band array surface and a conical hole array surface.The present application is inspired by the ability of cactus conical structure to direct liquid collection, the high-low rib structure of the bottle grass to quickly transport liquid, and the conical hole structure of duck bill to direct liquid collection.Combining the antisticking properties of the pitcher plant lubricated surface, a bionic antifouling coating is prepared and used for long-term antifouling in oil extraction and oil transportation.In a flowing oil-water environment, the long-term stable maintenance of the isolation layer is achieved, the purpose of inhibiting scale deposition and adhesion is achieved, and the long-term dynamic antifouling function in the oil-water environment can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional materials, which can be used in the fields of oil exploitation and oil transportation, and particularly relates to a biomimetic antifouling coating for complex environments and a preparation method and application thereof. BACKGROUND

[0002] In the oil industry, as oilfield development gradually matures, most of the oilfields in China enter the middle and late stages of exploitation. In the process of oil production, water injection is often used to supplement the formation pressure to improve oil production efficiency. However, the injected water usually has high salinity, which can cause a large amount of scale to precipitate and deposit, greatly reducing the oil production efficiency and causing safety problems.

[0003] Although traditional antifouling and descaling technologies, such as chemical methods such as chemical scale inhibitors and physical methods such as mechanical scale removal, can reduce the deposition and adhesion of scale to some extent, there are still many problems such as environmental pollution, high descaling cost, equipment downtime and damage due to the complex and diverse oil exploitation and transportation environment. Coating technology is one of the commonly used antifouling strategies for pipelines, and has the characteristics of simple operation, strong universality and environmental friendliness. As a new type of coating technology, lubricating coating has shown potential application prospects in the fields of ice resistance and antifouling. However, in complex external environments (such as water impact), the loss of lubricant on the surface of the coating often leads to the loss of its antifouling performance. Therefore, there is an urgent need to develop new lubricating coatings to enhance the stability of the coating and achieve long-term antifouling and descaling. SUMMARY

[0004] In order to improve the shortcomings of existing lubricating coating technology, the present application provides a biomimetic antifouling coating for complex environments and a preparation method thereof, which can achieve long-term antifouling of oil production and oil transportation pipelines. The biomimetic antifouling coating uses oil in the pipeline as an isolation layer to prevent direct contact between the mineral solution and the substrate layer, effectively inhibiting the adhesion and deposition of scale on the surface of the coating. The biomimetic antifouling coating collects oil in the pipeline through a substrate layer with a special structure (such as a conical needle, a rib belt, and a conical hole), achieving the purpose of enhancing the stability of the isolation layer and inhibiting the loss of antifouling performance in complex environments (such as fluid scouring, evaporation, dissolution, etc.).

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] A biomimetic antifouling coating, the biomimetic antifouling coating comprising a substrate layer and an isolation layer, the isolation layer being attached to the surface of the substrate layer; the isolation layer being an oil substance, the substrate layer being an oleophilic material, the substrate layer having at least one of a conical needle array structure, a rib belt array structure, and a conical hole array structure.

[0007] According to embodiments of the present application, the oleophilic material is selected from the group consisting of silica gel, polymeric material, oil gel, ionic liquid gel, and the like. Illustratively, the oleophilic material is selected from the group consisting of at least one of polydimethylsiloxane, fluoroelastomer, polyurethane elastomer, epoxy resin, fluoro-gel, (meth)acrylate oil gel (e.g. methyl acrylate, butyl acrylate, dodecyl acrylate, octadecyl acrylate, methyl methacrylate, lauryl methacrylate, and the like), hydrophobically modified nanocellulose aerogel, and vinylidene-hexafluoropropylene ionic liquid gel.

[0008] According to embodiments of the present application, the oil-based substance is selected from the group consisting of silicone oil, hydrocarbon-based substance, lubricating oil, and the like. Illustratively, the oil-based substance is selected from the group consisting of at least one of silicone oil, n-hexane, n-decane, n-dodecane, n-hexadecane, n-eicosane, n-tetracosane, gasoline, diesel, paraffin oil, and fluorine oil, and the like.

[0009] According to embodiments of the present application, the thickness of the base layer is not particularly defined and can be reasonably selected according to the use environment of the coating. For example, the thickness of the base layer is 1 mm to 40 mm, preferably 2 mm to 20 mm.

[0010] According to embodiments of the present application, the base layer is an oleophilic material adsorbed with an oil-based substance. The oil-based substance adsorbed in the oleophilic material is the same as or different from the oil-based substance in the isolation layer.

[0011] According to embodiments of the present application, the biomimetic antifouling coating can be prepared by a method comprising immersing the oleophilic material of the base layer in a system containing an oil-based substance for a certain period of time to obtain the biomimetic antifouling coating. The immersion time is, for example, less than 48 hours, for example, 0.5 h to 24 h.

[0012] The base layer is an oleophilic material with a specific structure, which can capture, collect, and store oil-based substances. The oil-based substances are thus adsorbed into the pores of the oleophilic material, and at the same time, a smooth layer of oil-based substances is left on the surface of the oleophilic material, forming the isolation layer. The oleophilic material can still maintain its solid characteristics and mechanical strength when containing the oil-based substances.

[0013] According to embodiments of the present application, the thickness of the isolation layer is, for example, 10 to 200 microns, for example, 10, 20, 40, 60, 80, 100, 120, 140, 180, or 200 microns.

[0014] According to an embodiment of the present application, the isolation layer is attached to the surface of the base layer by force (such as hydrogen bond, covalent bond, electrostatic interaction, etc.). Over time, the isolation layer can be lost due to evaporation, dissolution, and fluid scouring, etc. However, due to the structure of the base layer of the present application, which includes at least one of a conical needle array structure, a rib strip array structure, and a conical hole array structure, the base layer with the above structure can maintain the long-term stability of the isolation layer by rapid collection and conduction of oil substances, achieving the purpose of long-term antifouling in complex environments.

[0015] According to an embodiment of the present application, the conical needle array structure is an array of conical needles arranged on the surface of the base layer. Preferably, the surface of the conical needle has a ridge-like rough structure along the length of the conical needle. The height of the conical needle, the maximum diameter of the conical needle, and the spacing between adjacent conical needles can be appropriately changed according to the application environment, for example, the height of the conical needle is 100-2000 microns (for example, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or 2000 microns), the maximum diameter of the conical needle is 50-200 microns (for example, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 microns), and the spacing between adjacent conical needles is 100-2000 microns (for example, 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000 microns).

[0016] According to an embodiment of the present application, the conical needle array structure can be a polygonal array of conical needles, such as a quadrilateral array of conical needles, a pentagonal array of conical needles, or a hexagonal array of conical needles, etc.

[0017] According to an embodiment of the present application, the conical needle array structure is a cactus-like conical structure.

[0018] According to an embodiment of the present application, the rib strip array structure is a rib strip structure with protrusions on the surface of the base layer. The height of the rib strip (or the height of the protrusion), the width of the rib strip (or the width of the protrusion), and the spacing between adjacent rib strips (or the spacing between adjacent protrusions) can be appropriately changed according to the application environment, for example, the height of the rib strip is 5-500 microns, the width of the rib strip is 5-500 microns, and the spacing between adjacent rib strips is 5-500 microns.

[0019] Preferably, the height of adjacent ribbons (or the height of adjacent protrusions) is the same or different; illustratively, the ribbons include high ribbons and low ribbons, the height of the high ribbons is 10-500 microns, and the height of the low ribbons is 5-250 microns; further illustratively, there is at least one low ribbon between adjacent high ribbons, preferably 1-5 low ribbons between adjacent high ribbons.

[0020] According to an embodiment of the present application, the ribbons array structure is a bottlebrush-like ribbons structure.

[0021] According to an embodiment of the present application, the cone hole array structure is a structure having arrayed cone holes inside the base layer; preferably, the cone holes penetrate the base layer. In which, the cone holes form large holes on the side of the base layer where the base layer meets the isolation layer, and form small holes on the other side of the base layer. The diameter of the cone holes, the spacing between adjacent cone holes can be changed as appropriate according to the application environment. For example, the diameter of the large holes is 100-500 microns (e.g. 200-400 microns), the diameter of the small holes is 10-150 microns, and the spacing between adjacent large holes is 100-1000 microns.

[0022] According to an embodiment of the present application, the cone hole array can be a polygonal array arranged cone hole array structure, such as a quadrilateral array arranged cone hole array structure, a pentagonal array arranged cone hole array structure, or a hexagonal array arranged cone hole array structure, etc.

[0023] According to an embodiment of the present application, the cone hole array structure is a duckbill-like cone hole structure.

[0024] According to an embodiment of the present application, the cone needle array structure can achieve directional collection of small oil droplets in an oil-water environment, the driving force of the oil droplets on the surface of the cone needle mainly comes from the Laplace pressure caused by the curvature gradient of the surface; the ribbons array structure can quickly conduct oil, the driving force of the oil droplets on the surface mainly comes from the capillary force caused by the high-low rib structure; the cone hole array structure can achieve directional collection of small oil droplets in an oil-water environment, the driving force of the oil droplets on the surface mainly comes from the Laplace pressure caused by the asymmetric cone hole structure; the above structures can all maintain the stability of the isolation layer by collecting and quickly conducting oil, achieving the purpose of long-term anti-fouling.

[0025] According to the embodiment of the present application, the special structure (at least one of the cone needle array structure, the rib belt array structure, and the cone hole array structure) of the base layer can collect part of the oil in the oil-water environment to the surface of the base layer, continuously supplementing the isolation layer on the surface thereof; and the existence of the isolation layer, on one hand, the oil material with low surface energy can improve the nucleation barrier of the scale, which is not conducive to the nucleation of the scale; on the other hand, the adhesion between the scale and the oil material is very low, which inhibits the adhesion of the scale on the surface of the coating, and the purpose of scale prevention is achieved; at the same time, the continuous supplement of the oil material to the surface of the base layer can also avoid the isolation layer being washed away by the fluid, so that the coating loses its scale prevention performance, and the long-term scale prevention purpose is achieved.

[0026] The present application also provides a preparation method of the above-mentioned biomimetic scale prevention coating, which comprises the following steps:

[0027] A template with a cone hole array structure is prepared by punching on a substrate, and then an oilophilic material with a cone needle array structure is prepared by using an oilophilic material precursor as raw material through a mold turning method, and then the oilophilic material is immersed in an oil material to obtain a biomimetic scale prevention coating with a cone needle array structure;

[0028] Alternatively, a template with a rib belt array structure is prepared by etching on a substrate, and then an oilophilic material with a rib belt array structure is prepared by using an oilophilic material precursor as raw material through a mold turning method, and then the oilophilic material is immersed in an oil material to obtain a biomimetic scale prevention coating with a rib belt array structure;

[0029] Alternatively, an oilophilic material layer with a certain thickness is prepared on a substrate by using an oilophilic material precursor as raw material, and then an oilophilic material with a cone hole array structure is prepared by punching, and then the oilophilic material is immersed in an oil material to obtain a biomimetic scale prevention coating with a cone hole array structure;

[0030] Alternatively, any two or three of the above-mentioned methods are used to obtain a biomimetic scale prevention coating with a cone needle array and a cone hole array structure, a biomimetic scale prevention coating with a cone needle array and a rib belt array structure, a biomimetic scale prevention coating with a rib belt array and a cone hole array structure, and a biomimetic scale prevention coating with a cone needle array, a rib belt array and a cone hole array structure.

[0031] According to the present application, a template with a cone hole array structure and a rib belt array structure is prepared by punching and etching on a substrate, and then an oilophilic material with a cone needle array structure and a rib belt array structure is prepared by using an oilophilic material precursor as raw material through a mold turning method, and then the oilophilic material is immersed in an oil material to obtain a biomimetic scale prevention coating with a cone needle array structure and a rib belt array structure.

[0032] According to the present application, the prepared biomimetic antifouling coating with the structure of the array of conical needles, the array of ribbons, or the array of conical needles and the array of ribbons is punched, and then immersed in an oil substance to obtain the biomimetic antifouling coating with the structure of the array of conical needles and the array of conical holes, the structure of the array of ribbons and the array of conical holes, or the structure of the array of conical needles, the array of ribbons and the array of conical holes.

[0033] According to the present application, the substrate is selected from the group consisting of substrates that do not react with the precursor solution of the oleophilic material, and exemplarily, the substrate is selected from at least one of the group consisting of a silicon wafer, a polyethylene substrate, a polypropylene substrate, a polystyrene substrate, a polyvinyl chloride substrate, a polymethyl methacrylate substrate, and the like.

[0034] According to the present application, the precursor solution of the oleophilic material can be prepared into the oleophilic material through a polymerization reaction. The polymerization reaction can be a photopolymerization reaction or a thermal polymerization reaction. The precursor of the oleophilic material includes a prepolymer solution of the oleophilic material, an initiator, a crosslinking agent, and the like; and the precursor of the oleophilic material can be selected from, for example, a commercial Dow Corning 184 PDMS, a reaction system containing polyethylene glycol propylene glycol adipate and polyurethane, a reaction system containing butyl acrylate and a crosslinking agent, a commercial epoxy resin glue, and a reaction system containing n-butyl methacrylate and a crosslinking agent.

[0035] According to the embodiment of the present application, the method for preparing the biomimetic antifouling coating with the structure of the array of conical needles includes the following steps:

[0036] (1-1) punching a hole on a substrate to obtain a template with the structure of the array of conical holes;

[0037] (1-2) placing the template in a container with the side of the conical holes facing upward, pouring the precursor solution of the oleophilic material into the container, polymerizing, and then demolding and separating to obtain the oleophilic material with the structure of the array of conical needles;

[0038] (1-3) immersing the oleophilic material with the structure of the array of conical needles in an oil substance for a period of time to obtain the biomimetic antifouling coating with the structure of the array of conical needles.

[0039] In step (1-1), the punching can be performed by any conventional punching method. For example, a conical hole is punched on the substrate by a stainless steel needle to obtain a template having a conical hole array structure. The stainless steel needle is preferably a sewing needle or an acupuncture needle after sandpaper polishing, and the sandpaper is for example 100-2000 mesh. For example, the needle is polished in one direction from the root to the tip (for example, 20-50 times) by sandpaper (for example, 300 mesh sandpaper) to obtain a rough structure, and then cleaned with ethanol and deionized water and dried. In step (1-1), the conical hole is punched by a laser, for example, a LSC30 CO2 laser, and the hole depth can be controlled by the laser power.

[0040] In step (1-1), the conical hole is punched on the substrate by a stainless steel needle, and the punching of the conical hole is preferably performed by a dispensing machine. For example, the stainless steel needle and the substrate are fixed in a three-dimensional control system of the dispensing machine, and the substrate is punched by the stainless steel needle to obtain a template having a conical needle array structure.

[0041] In step (1-2), the demolding separation is to separate the material formed after polymerization and curing from the template.

[0042] According to an embodiment of the present application, the method for preparing the biomimetic antifouling coating having a rib strip array structure comprises the following steps:

[0043] (2-1) etching on a substrate to obtain a template having a rib strip array structure;

[0044] (2-2) placing the template in a container with the rib strip facing up, pouring an oilophilic material precursor solution into the container, polymerizing, and demolding and separating to obtain an oilophilic material having a rib strip array structure;

[0045] (2-3) immersing the oilophilic material having a rib strip array structure in an oil substance for a period of time to obtain a biomimetic antifouling coating having a rib strip array structure.

[0046] In step (2-1), the etching method is for example photolithography, laser engraving, and wet etching.

[0047] In step (2-2), the demolding separation is to separate the material formed after polymerization and curing from the template.

[0048] According to an embodiment of the present application, the method for preparing the biomimetic antifouling coating having a rib strip array structure comprises the following steps:

[0049] (3-1) coating an oilophilic material precursor solution on a substrate surface, polymerizing, and separating from the substrate to obtain an oilophilic material;

[0050] (3-2) punching the above obtained oleophilic material to obtain an oleophilic material with a conical hole array structure;

[0051] (3-3) immersing the oleophilic material with a conical hole array structure in an oil substance for a period of time to obtain a biomimetic anti-fouling coating with a conical hole array structure.

[0052] In step (3-1), the coating includes at least one of blade coating, spray coating, and immersion.

[0053] In step (3-2), the punching can be performed by any conventional punching method. For example, a laser is used to punch the oleophilic material, and the hole depth can be controlled by the laser power. Alternatively, a stainless steel needle and the oleophilic material are fixed in a three-dimensional control system of a dispensing machine, and the stainless steel needle is used to punch the oleophilic material in an array to obtain an oleophilic material with a conical hole array structure. For example, the stainless steel needle is a sewing needle or an acupuncture needle after sandpaper polishing, and the sandpaper is, for example, 100-2000 mesh. For example, the sandpaper (e.g., 300 mesh sandpaper) is polished in one direction from the root to the tip (e.g., 20-50 times), and a rough structure is polished out. The sandpaper is cleaned with ethanol and deionized water and dried.

[0054] The application also provides a use of the above biomimetic anti-fouling coating in oil field exploitation and transportation.

[0055] The application also provides an oil-water conveying pipeline, and the inner wall of the pipeline comprises the above biomimetic anti-fouling coating.

[0056] The application has the following advantages:

[0057] The application provides a biomimetic anti-fouling coating for complex environments. The biomimetic anti-fouling coating has at least one of a conical needle array surface, a rib band array surface, and a conical hole array surface. The application is inspired by the ability of cactus to directionally collect liquid, the ability of bottle grass to quickly transport liquid, and the ability of duck beak to directionally collect liquid, and combines the anti-adhesion property of a pitcher plant lubricated surface to prepare a biomimetic anti-fouling coating, which is used for long-term anti-fouling in oil extraction and transportation. In a flowing oil-water environment, the long-term stable maintenance of the isolation layer is achieved, the deposition and adhesion of water scale are inhibited, and the long-term dynamic anti-fouling function in an oil-water environment can be achieved.

[0058] The biomimetic anti-fouling coating of the application uses flowing oil in a pipeline as an isolation layer to prevent the deposition and adhesion of water scale, and is a long-term use, high-efficiency and energy-saving dynamic anti-fouling strategy. The application can be widely used in oil field exploitation and transportation, can reduce the deposition and adhesion of water scale on the surface of an oil pipe, improve the reusability of an oil-water pipeline, and reduce the cost of oil extraction. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 is a scanning electron microscope image of the bionic antifouling coating with a cone-shaped needle array structure according to an embodiment of the present application.

[0060] Figure 2 is a scanning electron microscope image of the bionic antifouling coating with a rib-belt array structure according to an embodiment of the present application.

[0061] Figure 3 is a scanning electron microscope image of the bionic antifouling coating with a cone-shaped hole array structure according to an embodiment of the present application. DETAILED DESCRIPTION

[0062] The application will be further described in conjunction with specific examples. It should be understood that the following examples are only illustrative and explanatory of the application, and should not be construed as limiting the scope of protection of the application. Any technology realized based on the above description of the application is included in the scope of protection intended by the application.

[0063] The experimental methods used in the following examples are conventional methods unless otherwise specified; the reagents, materials, etc. used in the following examples are commercially available unless otherwise specified.

[0064] Example 1

[0065] (1) Select commercially available stainless steel needles, and polish the root to the tip direction 30 times in one direction with 300-grit sandpaper to polish out a rough structure, and clean with ethanol and deionized water, and dry.

[0066] (2) Fix the stainless steel needles prepared in step (1) and a smooth high-density polyethylene sheet with a thickness of 5 mm in the three-dimensional control system of the dispensing machine, and use the stainless steel needles to array the punching on the polyethylene sheet to obtain a polyethylene sheet with a cone-shaped hole array, the depth of the cone-shaped hole is 1000 microns, the distance between adjacent cone-shaped holes is 250 microns, and a hexagonal array arrangement of the cone-shaped hole array structure is obtained.

[0067] (3) Place the polyethylene sheet with a cone-shaped hole array prepared in step (2) on the bottom of a container with the cone-shaped hole array facing up, mix the pre-polymer liquid of commercial Dow Corning 184 PDMS with the initiator at a mass ratio of 10:1, remove the air bubbles, pour into the container, and place in an oven, and polymerize at 80°C for 4h.

[0068] (4) Take out the coating after polymerization in step (3), separate the polyethylene sheet, and obtain a polydimethylsiloxane conical needle array structure arranged in a hexagonal array. The conical needle array structure is a structure with conical needles arranged in an array. The surface of each conical needle in the conical needle array structure has a ridge-shaped rough structure along the length direction of the conical needle. The height of the conical needle is 1000 microns, the diameter of the bottom of the conical needle is 100 microns, and the spacing between adjacent conical needles is 250 microns.

[0069] (5) The above-mentioned polydimethylsiloxane conical needle array structure is immersed in silicone oil for 24 hours to obtain a biomimetic antifouling coating with lipophilic properties.

[0070] (6) The above-mentioned biomimetic antifouling coating with a conical needle array structure is placed in an oil-water mixture for oil collection experiments. Due to the action of Laplace pressure, the oil droplets are self-driven from the tip of the conical needle to the root of the conical needle. After the oil droplets leave the conical needle, the next oil collection cycle can begin, thereby realizing continuous oil collection and maintaining the isolation layer, and achieving long-term resistance to water scale adhesion.

[0071] (7) The antifouling performance of the above-mentioned biomimetic antifouling coating with a conical needle array structure is tested under dynamic conditions. Specifically, the coating is cut to the appropriate size and placed in the pump tube of a peristaltic pump. A supersaturated calcium sulfate solution with a silicone oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 170 mL / min. After 24 hours, it is found that the coating surface has almost no water scale crystals adhered by scanning electron microscopy. Through atomic emission spectroscopy, it is found that the calcium content on the surface of the coating after five weeks of testing under dynamic conditions is 0.2 mg / cm 2 , which proves that the conical biomimetic antifouling coating has good antifouling effect.

[0072] (8) Under the same test conditions as in step (7), a large amount of water scale is deposited on the surfaces of stainless steel, PVC, and PE, which are 9.3 mg / cm 2 , 5.4 mg / cm 2 , and 3.9 mg / cm 2 , respectively. Among them, the water scale (calcium sulfate) deposition amount on the surface of the stainless steel (9.3 mg / cm 2 ) is about 50 times that of the conical biomimetic antifouling coating surface (0.2 mg / cm 2 ).

[0073] (9) The coating was cut into the appropriate size, and was put into the pump tube of a peristaltic pump. A supersaturated calcium sulfate solution with a silicon oil content of 0.5% was connected to the peristaltic pump, and the flow rate was set to 170 mL / min. After 24 hours, a small amount of scale was observed on the surface of the coating by scanning electron microscopy. A supersaturated calcium sulfate solution with a silicon oil content of 2% was connected to the peristaltic pump, and the flow rate was set to 170 mL / min. After 24 hours, almost no scale was deposited on the surface of the coating by scanning electron microscopy. A supersaturated calcium sulfate solution with a silicon oil content of 5% was connected to the peristaltic pump, and the flow rate was set to 170 mL / min. After 24 hours, almost no scale was deposited on the surface of the coating by scanning electron microscopy.

[0074] Therefore, it can be shown that when the oil content in the system to be treated is less than 2%, the loss of oil accounts for the main part, the coating quality decreases with the increase of time, and the oil loss rate is greater than the oil collection rate; when the oil content in the system to be treated is greater than or equal to 2%, the coating quality increases with the increase of time, and the oil collection rate is greater than the oil loss rate, which can prove that the isolation layer in the conical biomimetic antifouling coating can be replenished from the system to be separated at any time, and the purpose of antifouling under dynamic conditions is achieved. It is a long-term use, high-efficiency and energy-saving dynamic antifouling strategy, which can realize the long-term antifouling of oil extraction and oil transportation pipelines.

[0075] Example 2

[0076] (1) A prism band structure was formed on a silicon template by photolithography to obtain a template with a prism band array structure.

[0077] (2) Polyethylene glycol propylene glycol adipate was vacuum dehydrated at 110°C for 2h, cooled to 50°C, and then molten 4,4-diphenyl methane diisocyanate was added and stirred, and reacted at 85°C for 2h. Chain extender was added and mixed uniformly to obtain a prepolymer solution.

[0078] (3) The silicon template with a prism band structure prepared in step (1) was placed at the bottom of a container with the prism band structure facing up. The prepolymer solution obtained in step (2) was poured into the container, and the container was placed in an oven and cured at 120°C for 4h.

[0079] (4) The coating after curing in step (3) was taken out, and the silicon template was separated to obtain a polyurethane prism band array structure. The prism band array structure was a structure with raised prism bands. The prism band included high prism bands and low prism bands, and there were four low prism bands between adjacent high prism bands (the height of the high prism band was 50 microns, the height of the low prism band was 20 microns, and the distance between adjacent prism bands was 20 microns).

[0080] (5) The above polyurethane prism band array structure was immersed in liquid paraffin for 24h to obtain a biomimetic antifouling coating with a prism band array structure of a bottlebrush with lipophilic properties.

[0081] (6) Put the above-mentioned biomimetic anti-fouling coating with the rib-belt structure into an oil-water mixture for oil guiding experiment. Due to the effect of multi-stage capillary force, oil droplets can spread rapidly on the surface of the coating, so that continuous oil conduction and isolation layer maintenance are realized, and long-term water scale adhesion resistance is achieved.

[0082] (7) Test the water scale resistance of the above-mentioned biomimetic anti-fouling coating with the rib-belt structure under dynamic conditions. Specifically, the coating is cut into a suitable size and put into the pump tube of a peristaltic pump. A supersaturated calcium carbonate solution with a silicon oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 300 mL / min. After 24 hours, it is found by scanning electron microscopy that there is almost no water scale crystal adhesion on the surface of the coating. Quantitative analysis of calcium elements by atomic emission spectroscopy shows that the content of calcium carbonate on the surface of the coating is 0.3 mg / cm 2 , which proves that the rib-belt biomimetic anti-fouling coating has good anti-fouling effect.

[0083] Example 3

[0084] (1) Synthesize oil gel by emulsion polymerization method, using butyl acrylate as monomer, divinylbenzene as crosslinking agent, potassium persulfate as initiator, and sodium dodecyl benzene sulfonate as emulsifier. Take 70 mL of deionized water, 30 g of butyl acrylate, 0.3 g of divinylbenzene and 1.2 g of sodium dodecyl benzene sulfonate, emulsify for 15 min, add to a 250 mL three-necked flask equipped with reflux condenser and mechanical stirring, add 10 mL of potassium persulfate solution, react at 70℃ for 25 min; add 10 mL of potassium persulfate solution, react at 85℃ for 2 h, cool to room temperature; then add NaCl and stir to break the emulsion to obtain an oleophilic material precursor.

[0085] (2) The oleophilic material precursor obtained in step (1) is scraped onto a polytetrafluoroethylene substrate with a film scraper to form a 2 mm thick film, and is placed in a drying oven for drying.

[0086] (3) Take out the coating after polymerization and curing in step (2), separate the polytetrafluoroethylene substrate to obtain a gel sheet; fix the sheet on an LSC30 type CO2 laser, set the program for arrayed punching, set the laser power to 90%, and repeat twice to obtain a conical hole array structure.

[0087] (4) The above-mentioned conical hole array is a conical hole array with hexagonal array arrangement, the conical hole depth is 2000 microns, i.e. the conical hole penetrates the coating, the diameter of the large hole on the upper surface of the coating is 300 microns, the diameter of the small hole on the lower surface of the coating is 50 microns, and the spacing between adjacent large holes is 1000 microns.

[0088] (5) The above-mentioned conical hole array structure is immersed in silicon oil for 24 h to obtain a biomimetic anti-fouling coating with the conical hole array structure of the duck bill.

[0089] (6) The biomimetic antifouling coating with the tapered hole structure is placed in an oil-water mixture for oil collection experiments. Due to the effect of Laplace pressure, oil droplets can spontaneously move from one end of the large hole to the other end of the small hole, thereby realizing continuous oil collection and maintaining the isolation layer, and achieving long-term resistance to water scale adhesion.

[0090] (7) The antifouling performance of the biomimetic antifouling coating with the tapered hole array structure is tested under dynamic conditions. Specifically, the coating is cut to a suitable size and placed in the pump tube of a peristaltic pump. A supersaturated magnesium carbonate solution with a silicon oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 200 mL / min. After 24 hours, it is found by scanning electron microscopy that there is almost no water scale crystal adhesion on the surface of the coating. Quantitative analysis of the magnesium element by atomic emission spectroscopy shows that the content of magnesium carbonate on the surface of the coating is less than 0.5 mg / cm 2 , which proves that the biomimetic antifouling coating with the tapered hole array structure has good antifouling effect.

[0091] Example 4

[0092] (1) A commercially available stainless steel needle is selected, and 20 one-way polishings are performed from the root to the tip of the needle using 600 grit sandpaper. The needle is cleaned with ethanol and deionized water and dried.

[0093] (2) The stainless steel needle prepared in step (1) and a smooth high-density polyethylene sheet with a thickness of 10 mm are fixed in the three-dimensional control system of a dispensing machine. The stainless steel needle is used to array the holes on the polyethylene sheet to obtain a polyethylene sheet with a tapered needle array. The depth of the tapered hole is 600 microns, and the distance between adjacent tapered holes is 1000 microns, obtaining a square array of tapered needle hole arrays.

[0094] (3) The polyethylene sheet with a tapered needle hole array prepared in step (2) is placed at the bottom of a container with the tapered needle hole array facing up. The initiator is mixed with the prepolymer liquid of commercial Dow Corning 184 PDMS at a mass ratio of 10:1, and the bubbles are discharged. The mixture is poured into the container and placed in an oven at 90°C for 2h.

[0095] (4) The 2mm thick coating after polymerization in step (3) is taken out to obtain a square array of polydimethylsiloxane tapered needle array structures. The height of the tapered needle is 600 microns, the maximum diameter of the tapered needle (the diameter of the bottom of the tapered needle) is 80 microns, and the distance between adjacent tapered needles is 1000 microns.

[0096] (5) The conical needle array structure of step (4) is fixed in a LSC30 CO2 laser, and the program is set to carry out arrayed punching. The laser power is set to 90%, and the process is repeated twice to obtain a structure with both conical needle array and conical hole array. The depth of the conical hole is 2000 microns, i.e. the conical hole penetrates the coating, the diameter of the large hole on the upper surface of the coating is 300 microns, the diameter of the small hole on the lower surface of the coating is 50 microns, and the distance between adjacent large holes is 1000 microns.

[0097] (6) The array structure obtained in step (5) is soaked in fluorine oil, and after 24 hours, a cactus and duckbill synergistic biomimetic antifouling coating with lipophilic properties is obtained.

[0098] (7) The water scale resistance of the above-mentioned synergistic biomimetic antifouling coating is tested under dynamic conditions. Specifically, the coating is cut to the appropriate size and placed in the pump tube of a peristaltic pump. A supersaturated barium carbonate solution with a silicon oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 200 mL / min. After 24 hours, it is found by scanning electron microscopy that almost no water scale crystals adhere to the surface of the coating, and by atomic emission spectroscopy, the content of barium on the surface of the coating is found to be less than 0.1 mg / cm 2 , which proves that the synergistic biomimetic antifouling coating has good antifouling effect.

[0099] Example 5

[0100] (1) A prism band and conical hole structure is formed on a silicon substrate by photolithography to obtain a template with prism band array structure and conical hole array structure.

[0101] (2) A commercially available epoxy resin adhesive (Deli AB glue, including two tubes A and B, tube A is epoxy resin, and tube B is curing agent) is mixed uniformly at a mass ratio of 1:1 to obtain a prepolymer solution.

[0102] (3) The silicon substrate with prism band and conical hole array structure prepared in step (1) is placed at the bottom of a container with the prism band and conical hole structure facing up. The prepolymer solution obtained in step (2) is poured into the container, the bubbles are discharged, and it is placed in an oven for curing at room temperature for 4 hours.

[0103] (4) The coating after curing in step (3) is taken out, and the silicon template is separated to obtain an epoxy resin with conical needle array structure and prism band array structure. The prism band includes high prism bands and low prism bands, and there are four low prism bands between adjacent high prism bands (the height of the high prism band is 50 microns, the height of the low prism band is 20 microns, and the distance between adjacent prism bands is 20 microns); the height of the conical needle is 1000 microns, the maximum diameter of the conical needle is 100 microns, and the distance between adjacent conical needles is 250 microns.

[0104] (5) The epoxy resin with the cone and rib-belt array structure is immersed in fluorine oil for 24 hours to obtain a biomimetic antifouling coating with the cone and rib-belt array structure of the cactus and the genus skimmia, which has lipophilic properties.

[0105] (6) The biomimetic antifouling coating is taken out and placed in an oil-water mixture to conduct oil collection and conduction experiments. Due to the action of Laplace pressure, the oil droplets can spontaneously move from the tip of the cone needle to the root of the cone needle. Due to the action of multi-stage capillary force, the oil droplets can quickly spread on the surface of the coating, realizing continuous oil collection and conduction, thereby maintaining the isolation layer and achieving long-term resistance to water scale adhesion.

[0106] (7) The antifouling performance of the biomimetic antifouling coating is tested under dynamic conditions. Specifically, the coating is cut into a suitable size and placed in the pump tube of a peristaltic pump. A supersaturated calcium carbonate solution with a silicon oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 300 mL / min. After 24 hours, it is found by scanning electron microscopy that almost no water scale crystals adhere to the surface of the coating. Through atomic emission spectroscopy, the content of calcium on the surface of the coating is 0.1 mg / cm 2 , which proves that the biomimetic antifouling coating has good antifouling effect.

[0107] Example 6

[0108] (1) A rib-belt structure is formed on a silicon substrate by photolithography to obtain a template with a rib-belt array structure.

[0109] (2) n-Butyl methacrylate is used as a monomer, ethylene glycol dimethacrylate is used as a crosslinking agent, and 2-hydroxy-2-methylpropyl phenone is used as an initiator. The three are mixed uniformly in a mass ratio of 60:3:1 to obtain a prepolymer solution.

[0110] (3) The silicon substrate with the rib-belt structure prepared in step (1) is placed at the bottom of a container with the rib-belt structure facing up. The prepolymer solution obtained in step (2) is poured into the container. The power of the ultraviolet light reactor is set to 80%, and the reaction is carried out for 1 hour.

[0111] (4) The coating with a thickness of 2 mm after curing in step (3) is taken out, and the silicon template is separated to obtain a poly-n-butyl methacrylate rib-belt array structure. The rib-belt includes high rib-belts and low rib-belts, and there are two low rib-belts between adjacent high rib-belts (the height of the high rib-belt is 50 microns, the height of the low rib-belt is 20 microns, and the distance between adjacent rib-belts is 20 microns).

[0112] (5) The rib-belt array structure of step (4) is fixed in a LSC30 CO2 laser, and the program is set to carry out arrayed perforation. The laser power is set to 90%, and the process is repeated three times to obtain a structure with both rib-belt array and tapered hole array. The depth of the tapered hole is 2000 microns, i.e. the tapered hole penetrates the coating. The diameter of the large hole on the upper surface of the coating is 300 microns, the diameter of the small hole on the lower surface of the coating is 50 microns, and the distance between adjacent large holes is 1000 microns.

[0113] (6) The poly-n-butyl methacrylate with rib-belt array structure and tapered hole array structure is immersed in hexadecane, and after 24 hours, a bottlebrush and duckbill-shaped biomimetic antifouling coating with rib-belt array structure and tapered hole array structure with lipophilic properties is obtained.

[0114] (7) The biomimetic antifouling coating with rib-belt array structure and tapered hole array structure is placed in an oil-water mixture for oil guiding experiment. Due to the effect of multi-stage capillary force, the oil droplets can quickly spread on the surface of the coating. Due to the effect of Laplace pressure, the oil droplets can spontaneously move from one end of the large hole to the other end of the small hole, thereby realizing continuous oil collection and maintenance of the isolation layer, and achieving long-term resistance to water scale adhesion.

[0115] (8) The antifouling performance of the biomimetic antifouling coating with rib-belt array structure and tapered hole array structure is tested under dynamic conditions. Specifically, the coating is cut to an appropriate size and placed in the pump tube of a peristaltic pump. A supersaturated calcium carbonate solution with a silicon oil content of 2% is connected to the peristaltic pump, and the flow rate is set to 300 mL / min. After 24 hours, it is found by scanning electron microscopy that there is almost no water scale crystal adhesion on the surface of the coating. Through atomic emission spectroscopy, the calcium element is quantitatively analyzed, and the content of calcium carbonate on the surface of the coating is 0.1 mg / cm 2 , which proves that the biomimetic antifouling coating with rib-belt array structure and tapered hole array structure has good antifouling effect.

[0116] The above describes the embodiments of the present application. However, the present application is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A biomimetic long-term antifouling coating for use in an oil-water environment, wherein, The biomimetic long-term antifouling coating comprises a substrate layer and an isolation layer attached to the surface of the substrate layer; the isolation layer is an oil substance, and the substrate layer is an oleophilic material with the oil substance adsorbed thereon, and the substrate layer has a rib-belt array structure. The oleophilic material is selected from at least one of a polymer material, an oil gel and an ionic liquid gel; and the oil substance is selected from at least one of silicone oil, a hydrocarbon substance and lubricating oil. The rib-belt array structure is a rib-belt structure with protrusions on the surface of the substrate layer; the width of the rib-belt is 5-500 microns, the spacing between adjacent rib-belts is 20-500 microns; the rib-belt comprises high rib-belts and low rib-belts, the height of the high rib-belt is 50-500 microns, and the height of the low rib-belt is 20-250 microns; there are 1-5 low rib-belts between adjacent high rib-belts. The substrate layer with the rib-belt array structure can collect part of the oil in an oil-water environment on the surface of the substrate layer, and continuously supplement the isolation layer on the surface thereof; the oil substance continuously supplemented on the surface of the substrate layer can avoid the isolation layer being washed away by the fluid, so that the coating loses its antifouling performance, and the long-term antifouling purpose is achieved.

2. The biomimetic long-term antifouling coating according to claim 1, wherein, The biomimetic long-term antifouling coating is prepared by the following method: The oleophilic material of the substrate layer is soaked in a system containing the oil substance for a certain period of time to obtain the biomimetic long-term antifouling coating.

3. The biomimetic long-term antifouling coating according to claim 1, wherein, The oleophilic material is selected from silica gel.

4. The preparation method of the biomimetic long-term antifouling coating according to any one of claims 1-3, comprising the following steps: A template with a rib-belt array structure is prepared on a substrate by etching, an oleophilic material precursor is used as a raw material, a rib-belt array structure oleophilic material is prepared by a flip-molding method, and then the rib-belt array structure biomimetic long-term antifouling coating is obtained by immersing the rib-belt array structure oleophilic material in an oil substance.

5. The use of the biomimetic long-term antifouling coating according to any one of claims 1-3 in oilfield exploitation and transportation.

6. An oil-water conveying pipeline, wherein the inner wall of the pipeline comprises the biomimetic long-term antifouling coating according to any one of claims 1-3.

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