Preparation method of super-hydrophobic anti-drag coating

Abstract

The invention relates to the technical field of material science, in particular to a preparation method of a super-hydrophobic anti-drag coating, which comprises the following steps: S1, preparation of a precursor solution: preparing a comprehensive preparation device, and adding nanoparticles and a solvent into the comprehensive preparation device according to a mass ratio of (1-2): 20 to prepare the precursor solution; s2, base material treatment: adding an etching solution into the comprehensive preparation device, soaking the base material in the etching solution for 5-10 minutes, and meanwhile, oscillating the base material and the etching solution at 100-300 rpm by utilizing the comprehensive preparation device; hollow glass beads and a silane coupling agent are added into the comprehensive preparation device according to the mass ratio of 10: 1, and the comprehensive preparation device continues to oscillate for 15-20 min at the speed of 100-300 rpm; s3, coating spraying: spraying the precursor solution to the base material by using a comprehensive preparation device; and S4, curing treatment. According to the method, raw material stirring, base material oscillation and precursor solution spraying can be integrally carried out, multiple times of transferring and multiple devices are not needed, the preparation efficiency is effectively improved, and the preparation cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material science, in particular to a preparation method of super-hydrophobic drag-reducing coating. BACKGROUND

[0002] The super-hydrophobic drag-reducing coating is a functional coating with special micro-nano structure and low surface energy, which can significantly reduce the frictional resistance of fluid (such as water and oil) flowing on the solid surface. This technology has important application value in the fields of ship, pipeline transportation, aerospace and micro-fluidic devices.

[0003] In the prior art, a magnetic stirrer (such as RH basic 2 produced by Germany IKA Group) is used to stir the precursor solution, silane coupling agent and polymer matrix and other substances to prepare the precursor solution. A constant temperature oscillator (such as HS 501 digital produced by Germany IKA Group) is used to oscillate the substrate to facilitate chemical etching of the substrate. An operator uses a spray gun (such as SATAjet 1000B produced by Germany SATA Company) to uniformly spray the precursor solution on the surface of the substrate to form the super-hydrophobic drag-reducing coating.

[0004] Although the super-hydrophobic drag-reducing coating preparation method in the prior art can prepare the super-hydrophobic drag-reducing coating, the super-hydrophobic drag-reducing coating preparation method in the prior art requires the use of multiple devices to complete the super-hydrophobic drag-reducing coating preparation work, which is complex and has high cost. Therefore, it is necessary to propose a super-hydrophobic drag-reducing coating preparation method which does not need to use multiple devices and can reduce the operation difficulty and preparation cost. SUMMARY

[0005] To solve the above problems, the present application provides a preparation method of super-hydrophobic drag-reducing coating, which integrates the stirring of raw materials, oscillation of the substrate and spraying of the precursor solution, without the need for multiple transportation of raw materials and the use of multiple devices, thereby reducing the complexity and cost of preparation and effectively improving the preparation efficiency of the super-hydrophobic drag-reducing coating.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: a preparation method of super-hydrophobic drag-reducing coating, comprising the following steps:

[0007] S1, precursor solution preparation: prepare a comprehensive preparation device, add nanoparticles and solvent into the comprehensive preparation device according to a mass ratio of 1-2:20, stir them in the comprehensive preparation device at 400-500 rpm for 2-4 h to obtain a dispersion liquid; add a silane coupling agent to the dispersion liquid according to a mass ratio of 1-3:100, and continue to stir in the comprehensive preparation device at 400-500 rpm for 2-4 h; add a polymer matrix according to a mass ratio of 1-2:10, and continue to stir in the comprehensive preparation device at 200-220 rpm for 1-2 h to obtain a precursor solution.

[0008] S2, substrate treatment: add an etching solution into the comprehensive preparation device, and immerse the substrate in the etching solution for 5-10 min while oscillating the substrate and the etching solution in the comprehensive preparation device at 100-300 rpm; add hollow glass microspheres and a silane coupling agent into the comprehensive preparation device according to a mass ratio of 10:1, and continue to oscillate at 100-300 rpm for 15-20 min.

[0009] S3, coating spraying: fix the treated substrate by using the comprehensive preparation device, and spray the precursor solution onto the substrate by using the comprehensive preparation device.

[0010] S4, curing treatment: place the sprayed substrate into a drying oven, dry it at a drying temperature of 100-300℃ for 1-2 h to obtain a super-hydrophobic drag-reducing coating.

[0011] Further, the nanoparticles include one or more of SiO2 or TiO2.

[0012] Further, the silane coupling agent includes one or more of heptadecafluorodecyltrimethoxysilane or octyltriethoxysilane.

[0013] Further, the polymer matrix includes one or more of PDMS or fluororesin.

[0014] Further, the solvent includes one of ethanol or isopropyl alcohol.

[0015] The above scheme has the following beneficial effects:

[0016] 1. The existing preparation method of the super-hydrophobic drag-reducing coating needs to use multiple devices, such as stirring devices, vibration devices and spraying devices, to complete the preparation and spraying of the precursor solution, resulting in high preparation cost. The present method integrates the raw material stirring, substrate oscillation and precursor solution spraying into one device, effectively reducing the preparation cost of the super-hydrophobic drag-reducing coating.

[0017] 2. Existing methods for preparing superhydrophobic drag-reducing coatings require the use of multiple devices, leading to repeated transfer of raw materials, which increases preparation time and reduces efficiency. Furthermore, spillage during transfer can result in material waste and reduced yield. This invention integrates raw material stirring, substrate oscillation, and precursor solution spraying, eliminating the need for raw material transfer, effectively avoiding waste of raw materials and preparation time, and improving preparation efficiency.

[0018] 3. Unlike existing methods for preparing superhydrophobic drag-reducing coatings, this method involves agitating the substrate and etching solution during the etching process. This ensures uniform and sufficient contact between the substrate surface and the etching solution, forming uniformly dense etched microgrooves and increasing the surface roughness of the substrate. This facilitates bonding with the precursor solution and hollow glass microspheres. Furthermore, the addition of hollow glass microspheres and a silane coupling agent allows the microspheres to adhere to the substrate surface, forming a protective structure. Combined with the subsequent spraying of the precursor solution, a multilayer structure consisting of the substrate, hollow glass microspheres, and the precursor solution is formed. The hollow glass microspheres enhance the bonding force between the precursor solution and the substrate, and their inherent hydrophobicity and drag-reducing properties further improve the hydrophobicity and drag-reducing effect of the prepared superhydrophobic drag-reducing coating.

[0019] Furthermore, the integrated preparation device includes a controller and a base, with a first support plate and a second support plate fixedly connected to the base; the second support plate is provided with a stirring component for stirring raw materials; and the base is also provided with a fixing component for fixing the substrate.

[0020] The mixing assembly includes a drive unit embedded in a first support plate. A first turntable is fixedly connected to the output shaft at one end of the drive unit, and a telescopic rod is fixedly connected to the output shaft at the other end of the drive unit. A main bevel gear is coaxially fixedly connected to the output shaft of the telescopic rod, and a secondary bevel gear meshes with the main bevel gear. A mixing shaft is fixedly connected to the top of the secondary bevel gear. A mixing box is fixedly connected to the second support plate. The mixing shaft passes through the bottom of the mixing box to the top of the mixing box and rotates with it. Several mixing rods are fixedly connected to the part of the mixing shaft located inside the mixing box. A second turntable is fixedly connected to the top of the mixing rods.

[0021] The first turntable is equipped with a spraying assembly for spraying the precursor solution, and the second turntable is equipped with an oscillation assembly for oscillating the substrate. The controller is used to control the operation of the drive components, thereby driving the telescopic rod and the first turntable to rotate. The controller is also used to control the operation of the telescopic rod, thereby causing the main bevel gear and the secondary bevel gear to mesh.

[0022] Beneficial effects: Operators only need to control the drive components through the controller. The transmission of the main bevel gear and the secondary bevel gear drives the stirring shaft and stirring rod to rotate, thereby uniformly mixing the raw materials and improving the finished quality of the superhydrophobic drag-reducing coating.

[0023] Furthermore, the spraying assembly includes a first eccentric rod hinged to the side of the first turntable away from the drive component, and a first slide rod hinged to the top of the first eccentric rod; a limit block is fixedly connected to the side wall of the first support plate, and the first slide rod slides vertically with the limit block; a scraper is fixedly connected to the top of the first slide rod, and the scraper has several spray holes; a piston rod is fixedly connected to the bottom of the scraper, and a piston box is fixedly connected to the top of the base; the bottom of the piston rod extends into the piston box and is fixedly connected to a piston plate, and the piston plate slides vertically with the inner side wall of the piston box; the piston box is connected to the mixing tank, and a first one-way valve for liquid inlet is connected at the connection point between the two; all spray holes are connected to the piston box, and a second one-way valve for liquid outlet is connected at the connection point between the two; the controller is used to control the operation of the first one-way valve and the second one-way valve.

[0024] Beneficial effects: The scraper can slide up and down along the surface of the substrate. At the same time, during the process of the scraper sliding up and down, the piston box will draw the precursor solution in the mixing tank through the first one-way valve and deliver the precursor solution to the spray hole through the second one-way valve, thereby spraying the precursor solution onto the surface of the substrate.

[0025] Furthermore, the oscillation assembly includes a second eccentric rod hinged to the top of the second turntable, a second slide rod hinged to the end of the second eccentric rod away from the second turntable, a limit rod fixedly connected to the top of the base, and the second slide rod and the top of the limit rod slidingly engaged laterally; an oscillation box is fixedly connected to the end of the second slide rod away from the second eccentric rod, a support seat is slidably engaged at the bottom of the oscillation box, and the bottom of the support seat is fixedly connected to the top of the base.

[0026] Beneficial effects: The oscillation chamber can oscillate the substrate evenly, so that the substrate surface is in uniform and sufficient contact with the etching solution and hollow glass microspheres, thereby improving the coating preparation effect.

[0027] Furthermore, the fixing component includes a placement groove opened on the top of the base, the placement groove is located below the scraper, the bottom wall of the placement groove has several negative pressure holes, the side wall of the base is connected to a negative pressure pump, and the negative pressure holes are all connected to the negative pressure pump; the controller is used to control the operation of the negative pressure pump, thereby drawing gas from the negative pressure holes to generate negative pressure, thereby adsorbing and fixing the substrate.

[0028] Beneficial effects: The negative pressure pump generates negative pressure in the negative pressure orifice, thereby adsorbing and fixing the substrate, keeping it stable, and facilitating stable and uniform coating by the scraper. During spraying, the precursor solution flows into the placement tank due to gravity along the substrate surface. This portion of the precursor solution wets the part of the substrate in the placement tank, improving the overall coverage of the precursor solution. After spraying, the operator removes the substrate. At this time, the operator can clean the placement tank while keeping the negative pressure pump running. The liquid in the placement tank will be discharged through the negative pressure orifice by the negative pressure pump, thus ensuring the cleanliness of the placement tank and facilitating its recycling.

[0029] Furthermore, the top of the placement slot is conical.

[0030] Beneficial effects: The conical placement tank has a larger opening at the top, which better collects and contains the precursor solution flowing down the substrate surface. It also makes it easier for operators to place the substrate into the placement tank, reducing the risk of bumps and knocks.

[0031] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0032] Figure 1 This is a schematic diagram illustrating the steps of the preparation method of the superhydrophobic drag-reducing coating of the present invention.

[0033] Figure 2 This is an isometric view of the integrated preparation apparatus in the preparation method of the superhydrophobic drag-reducing coating of the present invention.

[0034] Figure 3 This is a side view of the drive component of the integrated preparation apparatus in the preparation method of the superhydrophobic drag-reducing coating of the present invention.

[0035] Figure 4 This is a side cross-sectional view of the mixing tank of the integrated preparation apparatus in the preparation method of the superhydrophobic drag-reducing coating of the present invention.

[0036] Figure 5 This is a side cross-sectional view of the piston box of the integrated preparation apparatus in the preparation method of the superhydrophobic drag-reducing coating of the present invention.

[0037] The reference numerals in the accompanying drawings of the instruction manual include: 1. Base; 2. First support plate; 3. Second support plate; 4. Dual-head motor; 5. First turntable; 6. Telescopic rod; 7. Main bevel gear; 8. Secondary bevel gear; 9. Stirring shaft; 10. Stirring box; 11. Stirring rod; 12. Second turntable; 13. First eccentric rod; 14. First slide rod; 15. Limiting block; 16. Scraper; 17. Piston rod; 18. Piston box; 19. Piston plate; 20. First one-way valve; 21. Second one-way valve; 22. Second eccentric rod; 23. Second slide rod; 24. Shaking box; 25. Support base; 26. Placement slot; 27. Negative pressure pump; 28. Limiting rod. Detailed Implementation

[0038] The following detailed description illustrates the specific implementation method:

[0039] Example 1:

[0040] like Figure 1 As shown, a method for preparing a superhydrophobic drag-reducing coating includes the following steps:

[0041] S1, precursor solution preparation: prepare a comprehensive preparation device, add nanoparticles (the nanoparticles include one or more of SiO2 or TiO2, and the embodiment selects SiO2) and solvent (the solvent includes one or more of ethanol or isopropanol, and the embodiment selects ethanol) into the comprehensive preparation device at a mass ratio of 1:20, and use the comprehensive preparation device to stir them at 400 rpm for 2 h to prepare a dispersion liquid; add a silane coupling agent (the silane coupling agent includes one or more of heptadecafluorodecyltrimethoxysilane or octyltriethoxysilane, and the embodiment selects heptadecafluorodecyltrimethoxysilane) to the dispersion liquid at a mass ratio of 1:100, and continue to stir them at 400 rpm for 2 h using the comprehensive preparation device; add a polymer matrix (the polymer matrix includes one or more of PDMS or fluororesin, and the embodiment selects PDMS) at a mass ratio of 1:10, and continue to stir them at 200 rpm for 1 h using the comprehensive preparation device to prepare a precursor solution.

[0042] S2, substrate treatment: add an etching solution (the embodiment selects HCL) into the comprehensive preparation device, and immerse a substrate (the embodiment selects an aluminum alloy) in the etching solution for 5 min while oscillating the substrate and the etching solution at 100 rpm using the comprehensive preparation device; add hollow glass microspheres and heptadecafluorodecyltrimethoxysilane into the comprehensive preparation device at a mass ratio of 10:1, and continue to oscillate them at 100 rpm for 20 min using the comprehensive preparation device.

[0043] S3, coating spraying: fix the treated substrate using the comprehensive preparation device, and spray the precursor solution onto the substrate using the comprehensive preparation device.

[0044] S4, curing treatment: place the sprayed substrate into a drying oven, dry it at a drying temperature of 150℃ for 1 h to prepare a super-hydrophobic drag-reducing coating.

[0045] I. Experimental preparation

[0046] Experimental group: use the comprehensive preparation device to prepare a super-hydrophobic drag-reducing coating.

[0047] Control group: use a magnetic stirrer (the embodiment selects RH basic 2 produced by Germany IKA Group), a constant-temperature oscillator (the embodiment selects HS 501 digital produced by Germany IKA Group), and a spray gun (the embodiment selects SATAjet 1000B produced by Germany SATA Company) to prepare a super-hydrophobic drag-reducing coating.

[0048] II. Experimental process

[0049] The same raw materials and base materials, the same stirring oscillation parameters are used in the experimental group and the control group to prepare the super-hydrophobic drag-reducing coating for 5 times. The preparation time and preparation yield of each time in the experimental group and the control group are recorded, and the average preparation time and average preparation yield are calculated. After the experiment, the satisfaction degree of the operator to the operation process and the satisfaction degree of the product quality are recorded, and the satisfaction degree is divided into five levels: satisfied, more satisfied, general, worse and poor.

[0050] III. Experimental results

[0051] Table 1 Comparison table of experimental data

[0052]

[0053] Table 1 is a comparison table of experimental data of the experimental group and the control group. According to Table 1, the average preparation time of the experimental group is significantly shorter than that of the control group. The reason may be that the experimental group does not need to transport the raw materials multiple times and does not need to replace the preparation equipment, so the preparation time is shorter.

[0054] The use amount of raw materials is the same, and the average preparation yield of the experimental group is greater than that of the control group. The reason may be that the raw materials of the control group are lost during the multiple transportation processes or some of the raw materials are attached to each device, resulting in waste of raw materials and affecting the yield.

[0055] The satisfaction degree of the operation process of the experimental group is better than that of the control group. The reason may be that the operation of the experimental group is simple, only one device needs to be operated to prepare the super-hydrophobic drag-reducing coating, and multiple transportation is not needed, so the labor consumption is low and the preparation time is shorter. Therefore, the satisfaction degree of the operation process of the experimental group is better than that of the control group.

[0056] The satisfaction degree of the product quality of the experimental group is better than that of the control group. The reason may be that the raw materials of the control group are easily contaminated by external impurities during multiple transportation, which affects the final product quality. The raw materials of the experimental group do not need to be transported multiple times, which greatly reduces the risk of the raw materials being affected by external impurities. Therefore, the satisfaction degree of the product quality of the experimental group is better than that of the control group.

[0057] According to the experiment, it is concluded that the preparation method of the super-hydrophobic drag-reducing coating in this experiment significantly reduces the labor consumption and time consumption, and effectively improves the preparation efficiency.

[0058] Example 2

[0059] As shown in Figure 2 different from the above examples, the comprehensive preparation device includes a controller and a base 1, and the first support plate 2 and the second support plate 3 are bolted and connected on the base 1. The stirring assembly for stirring the raw materials is arranged on the second support plate 3. The fixing assembly for fixing the base material is also arranged on the base 1.

[0060] As Figure 1 and Figure 4 shown, the stirring assembly comprises a driving member embeddedly installed in the first support plate 2, in the embodiment, the driving member is selected as a double-head motor 4; a first rotating disc 5 is bolted and fixed on one end output shaft of the double-head motor 4, an extension rod 6 is bolted and fixed on the other end output shaft of the double-head motor 4, a main bevel gear 7 is coaxially bolted and fixed on the output shaft of the extension rod 6, a sub bevel gear 8 is engaged with the main bevel gear 7, and a stirring shaft 9 is bolted and fixed on the top of the sub bevel gear 8; a stirring box 10 is welded on the second support plate 3, the stirring shaft 9 penetrates through the bottom of the stirring box 10 to the top of the stirring box 10 and is rotationally matched therewith, and a plurality of stirring rods 11 are welded on the part of the stirring shaft 9 located in the stirring box 10; a second rotating disc 12 is bolted and fixed on the top of the stirring rod 11.

[0061] As Figure 1 and Figure 3 shown, specifically, the extension rod 6 is started by the controller to make the main bevel gear 7 and the sub bevel gear 8 engaged; then the double-head motor 4 is started, the right side output shaft of the double-head motor 4 will drive the extension rod 6 to rotate and in turn drive the main bevel gear 7 to rotate, since the main bevel gear 7 and the sub bevel gear 8 are engaged, therefore, the main bevel gear 7 will drive the sub bevel gear 8 to rotate and in turn drive the stirring shaft 9 and the stirring rod 11 to rotate, so as to stir the raw materials in the stirring box 10.

[0062] The first rotating disc 5 is provided with a spraying assembly for spraying precursor solution, and the second rotating disc 12 is provided with an oscillation assembly for oscillating the substrate. The controller is used to control the operation of the double-head motor 4, thereby driving the extension rod 6 and the first rotating disc 5 to rotate, and the controller is also used to control the operation of the extension rod 6, thereby making the main bevel gear 7 and the sub bevel gear 8 engaged.

[0063] As Figure 1 and Figure 5 shown, the spraying assembly comprises a first eccentric rod 13 hinged to the side of the first rotating disc 5 away from the double-head motor 4, and a first sliding rod 14 is hinged to the top of the first eccentric rod 13; a limiting block 15 is bolted and fixed on the side wall of the first support plate 2, and the first sliding rod 14 is vertically slidingly matched with the limiting block 15; a scraper 16 is bolted and fixed on the top of the first sliding rod 14, a plurality of spraying holes are formed in the scraper 16; a piston rod 17 is bolted and fixed on the bottom of the scraper 16, a piston box 18 is bolted and fixed on the top of the base 1, the bottom of the piston rod 17 extends into the piston box 18 and is bolted and fixed with a piston plate 19, and the piston plate 19 is vertically slidingly matched with the inner side wall of the piston box 18; the piston box 18 is communicated with the stirring box 10, and a first one-way valve 20 for liquid inlet is communicated at the communication part therebetween; the spraying holes are all communicated with the piston box 18, and a second one-way valve 21 for liquid outlet is communicated at the communication part therebetween; and the controller is used to control the operation of the first one-way valve 20 and the second one-way valve 21.

[0064] AsFigure 1 And Figure 3 As shown in the drawings, in particular, when the double-head motor 4 is started, the left output shaft of the double-head motor 4 will drive the first turntable 5 to rotate, and then drive the first eccentric rod 13 to rotate, and the first eccentric rod 13 will drive the first sliding rod 14 to slide up and down along the limiting block 15, and then drive the scraper 16 to slide vertically along the surface of the substrate; At the same time, the scraper 16 will drive the piston rod 17 and the piston plate 19 to slide up and down in the piston box 18, and in this process, the piston box 18 will suck the precursor solution in the stirring box 10 through the first one-way valve 20, and then deliver the precursor solution to the spraying hole through the second one-way valve 21, and then spray the precursor solution to the surface of the substrate. With the reciprocating sliding of the scraper 16, the precursor solution can be sprayed more uniformly and comprehensively.

[0065] As shown in the drawings, Figure 1 The oscillation assembly includes a second eccentric rod 22 hinged to the top of the second turntable 12, a second sliding rod 23 hinged to the end of the second eccentric rod 22 away from the second turntable 12, a limiting rod 28 welded to the top of the base 1, and the second sliding rod 23 and the limiting rod 28 are in top transverse sliding fit; The second sliding rod 23 is welded with an oscillation box 24 at the end away from the second eccentric rod 22, the oscillation box 24 is slidably connected with a support seat 25 at the bottom, and the support seat 25 is fixedly connected with the top of the base 1 by bolts.

[0066] In particular, when the stirring shaft 9 rotates, the second turntable 12 will also rotate, and then drive the second eccentric rod 22 to rotate, and the second eccentric rod 22 will drive the second sliding rod 23 to slide horizontally along the limiting rod 28, so as to drive the oscillation box 24 to slide horizontally along the support seat 25, and then the substrate, etching solution and hollow glass microspheres in the oscillation box 24 are vibrated, so that the surface of the substrate is in uniform and sufficient contact with the etching solution and hollow glass microspheres, and the preparation effect of the coating is improved.

[0067] As shown in the drawings, Figure 1 The fixing assembly includes a placing groove 26 opened in the top of the base 1, and the placing groove 26 is located below the scraper 16. A plurality of negative pressure holes (not shown in the figure) are opened in the inner bottom wall of the placing groove 26, and the side wall of the base 1 is communicated with a negative pressure pump 27, and the negative pressure holes are communicated with the negative pressure pump 27; The controller is used for controlling the operation of the negative pressure pump 27, so as to suck the gas at the negative pressure holes to generate negative pressure, so as to adsorb and fix the substrate.

[0068] Specifically, the operator starts the negative pressure pump 27 through the controller, the negative pressure pump 27 can generate negative pressure in the negative pressure hole, thereby adsorbing and fixing the substrate, keeping the substrate stable, and facilitating the stable and uniform coating of the substrate by the scraper 16. During the spraying process, the precursor solution will flow into the placement groove 26 along the surface of the substrate due to gravity, and this part of the precursor solution will infiltrate the part of the substrate located in the placement groove 26, improving the comprehensiveness of the precursor solution coating. After spraying is completed, the operator removes the substrate, at this time, the operator can clean the placement groove 26, and keep the negative pressure pump 27 started, the liquid in the placement groove 26 will be discharged by the negative pressure pump 27 through the negative pressure hole, thereby ensuring the cleanliness of the placement groove and facilitating recycling.

[0069] Compared with the mechanical clamping (such as the SCHUNK KGG 50 flat jaw clamp in the prior art) or handheld fixing in the prior art, the present embodiment fixes the bottom of the substrate by negative pressure adsorption, which can greatly reduce the shielding of the surface of the substrate. Compared with the electromagnetic adsorption in the prior art, the negative pressure adsorption can act on metal and non-metal substrates, while the electromagnetic adsorption fixing can only act on metal substrates. Through the design of negative pressure adsorption, the present embodiment effectively improves the comprehensiveness of the spraying work.

[0070] As shown in Figure 2 , the top of the placement groove 26 is conical, so that the top of the placement groove 26 has a larger opening, thereby better collecting and containing the precursor solution flowing downward along the surface of the substrate, and also facilitating the operator to put the substrate into the placement groove 26, reducing the risk of bumping.

[0071] The specific implementation process is as follows:

[0072] As shown in Figure 1 , in the initial state, the output shaft of the telescopic rod 6 is in the extended state, and the main bevel gear 7 and the auxiliary bevel gear 8 are kept engaged; the first one-way valve 20, the second one-way valve 21 and the negative pressure pump 27 are all in the closed state.

[0073] The operator inputs the raw materials into the stirring box 10, at the same time, puts the substrate into the oscillation box 24, and inputs the etching liquid and hollow glass beads into the oscillation box 24; then starts the double-head motor 4 through the controller, the double-head motor 4 will drive the telescopic rod 6 to rotate and the main bevel gear 7 to rotate, thereby driving the auxiliary bevel gear 8, the stirring shaft 9 and the stirring rod 11 to rotate, so as to stir the raw materials and prepare the precursor solution; at the same time, the stirring shaft 9 will also drive the second turntable 12 and the second eccentric rod 22 to rotate, thereby driving the second sliding rod 23 to slide transversely along the limiting rod 28, so that the oscillation box 24 oscillates the substrate, the etching liquid and the hollow glass beads.

[0074] When the substrate, etching solution and hollow glass microspheres oscillation is completed, the substrate is taken out, the negative pressure pump 27 is started by the controller, and the bottom of the substrate is adsorbed by the negative pressure pump 27 and the negative pressure hole, so that the substrate is kept stable, and the subsequent scraper 16 can be used to smear the precursor solution on the substrate.

[0075] After the preparation of the precursor solution is completed, the telescopic rod 6 is controlled to operate by the controller, so that the main bevel gear 7 is retracted by the output shaft of the telescopic rod 6, and the auxiliary bevel gear 8 loses power and gradually stops rotating, so as to keep the precursor solution stationary and avoid excessive stirring of the precursor solution during stationary, which causes the molecular chain of the polymer matrix to break, so that the cross-linking density of the finally formed super-hydrophobic drag reduction coating is uneven, and the mechanical strength is reduced.

[0076] At this time, the operator keeps the double-head motor 4 running by the controller, and opens the first one-way valve 20 and the second one-way valve 21, the first rotating disc 5 and the first eccentric rod 13 are rotated by the left output shaft of the double-head motor 4, the first eccentric rod 13 drives the first sliding rod 14 to slide up and down along the limiting block 15, and then drives the scraper 16 to slide vertically along the surface of the substrate; at the same time, the scraper 16 drives the piston rod 17 and the piston plate 19 to slide up and down in the piston box 18, when the scraper 16 slides from bottom to top along the surface of the substrate, the piston box 18 sucks the precursor solution in the stirring box 10 through the first one-way valve 20, when the scraper 16 slides from top to bottom along the surface of the substrate, the piston box 18 delivers the precursor solution to the spraying hole through the second one-way valve 21, when the scraper 16 slides, the precursor solution is sprayed from top to bottom on the surface of the substrate through the spraying hole, so that the precursor solution can be coated from the top of the substrate to the bottom of the substrate, and the uniformity of the coating is improved.

[0077] After spraying is completed, the substrate is placed in the drying box, and dried at 150℃ for 1h to obtain a super-hydrophobic drag reduction coating.

[0078] The existing preparation method of the super-hydrophobic drag reduction coating needs to use multiple devices, such as stirring equipment, vibration equipment and spraying equipment, to complete the preparation and spraying of the precursor solution, which leads to high preparation cost, and because multiple devices are needed, the raw materials need to be repeatedly transported, which increases the preparation time and reduces the preparation efficiency, and the raw materials may be spilled or even contaminated during the transportation process, which leads to waste of raw materials and reduces product yield and product quality; only one device is needed in the embodiment to integrate the stirring of raw materials, oscillation of the substrate and spraying of the precursor solution, which effectively reduces the preparation cost of the super-hydrophobic drag reduction coating; and in the embodiment, the raw materials do not need to be transported, which effectively reduces the risk of waste and pollution of raw materials, improves product yield and product quality, saves preparation time, and improves preparation efficiency.

[0079] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and can not be enumerated. The obvious changes or variations derived from the above description are still within the protection scope of the present application.

Claims

1. A method of making a superhydrophobic drag-reducing coating, characterized in that, Comprising the following steps: S1, precursor solution preparation: prepare a comprehensive preparation device, add nanoparticles and solvent to the comprehensive preparation device in a mass ratio of 1-2:20, stir the mixture in the comprehensive preparation device at 400-500 rpm for 2-4 h to obtain a dispersion liquid; add a silane coupling agent to the dispersion liquid in a mass ratio of 1-3:100, and continue to stir the mixture in the comprehensive preparation device at 400-500 rpm for 2-4 h; add a polymer matrix to the mixture in a mass ratio of 1-2:10, and continue to stir the mixture in the comprehensive preparation device at 200-220 rpm for 1-2 h to obtain a precursor solution; S2, substrate treatment: add an etching solution to the comprehensive preparation device, immerse the substrate in the etching solution for 5-10 min, and oscillate the substrate and the etching solution in the comprehensive preparation device at 100-300 rpm; add hollow glass microspheres and a silane coupling agent to the comprehensive preparation device in a mass ratio of 10:1, and continue to oscillate the mixture in the comprehensive preparation device at 100-300 rpm for 15-20 min; S3, coating spraying: fix the treated substrate in the comprehensive preparation device, and spray the precursor solution on the substrate in the comprehensive preparation device; S4, curing treatment: place the substrate after spraying in a drying oven, dry the substrate at a temperature of 100-300°C for 1-2 h, and obtain a super-hydrophobic drag-reducing coating.

2. The method of claim 1, wherein the superhydrophobic drag-reducing coating is prepared by, The nanoparticles include one or more of SiO2 or TiO2.

3. The method of claim 2, wherein the superhydrophobic drag-reducing coating is prepared by, The silane coupling agent includes one or more of heptadecafluorodecyltrimethoxysilane or octyltriethoxysilane.

4. The method of claim 3, wherein the superhydrophobic drag-reducing coating is prepared by, The polymer matrix includes one or more of PDMS or fluororesin.

5. The method of claim 4, wherein the superhydrophobic drag-reducing coating is prepared by, The solvent includes one of ethanol or isopropanol.

6. The method of claim 5, wherein the superhydrophobic drag-reducing coating is prepared by, The comprehensive preparation device includes a controller and a base (1), the base (1) is fixedly connected with a first support plate (2) and a second support plate (3); the second support plate (3) is provided with a stirring assembly for stirring raw materials; the base (1) is also provided with a fixing assembly for fixing the substrate; The stirring assembly includes a driving member embeddedly installed in the first support plate (2), a first turntable (5) is fixedly connected to the output shaft at one end of the driving member, a telescopic rod (6) is fixedly connected to the output shaft at the other end of the driving member, a main bevel gear (7) is coaxially fixedly connected to the output shaft of the telescopic rod (6), a secondary bevel gear (8) is engaged with the main bevel gear (7), and a stirring shaft (9) is fixedly connected to the top of the secondary bevel gear (8); a stirring box (10) is fixedly connected to the second support plate (3), the stirring shaft (9) penetrates from the bottom to the top of the stirring box (10) and is rotationally matched therewith, and a plurality of stirring rods (11) are fixedly connected to the portion of the stirring shaft (9) in the stirring box (10); a second turntable (12) is fixedly connected to the top of the stirring rod (11); The first turntable (5) is provided with a spraying assembly for spraying the precursor solution, and the second turntable (12) is provided with an oscillation assembly for oscillating the substrate; the controller is used to control the operation of the driving member, thereby driving the rotation of the telescopic rod (6) and the first turntable (5), and the controller is also used to control the operation of the telescopic rod (6), thereby enabling the main bevel gear (7) and the secondary bevel gear (8) to engage.

7. The method of claim 6, wherein the superhydrophobic drag-reducing coating is prepared by, The spraying assembly comprises a first eccentric rod (13) hinged to the first rotating disc (5) away from the driving member, and a first sliding rod (14) hinged to the top of the first eccentric rod (13); the side wall of the first supporting plate (2) is fixedly connected with a limiting block (15), and the first sliding rod (14) is in vertical sliding fit with the limiting block (15); the top of the first sliding rod (14) is fixedly connected with a scraper (16), and a plurality of spraying holes are formed in the scraper (16); the bottom of the scraper (16) is fixedly connected with a piston rod (17), the top of the base (1) is fixedly connected with a piston box (18), the bottom of the piston rod (17) extends into the piston box (18) and is fixedly connected with a piston plate (19), and the piston plate (19) is in vertical sliding fit with the inner side wall of the piston box (18); the piston box (18) is communicated with the stirring box (10), and a first one-way valve (20) for liquid inlet is arranged at the communication position; the spraying holes are all communicated with the piston box (18), and a second one-way valve (21) for liquid discharge is arranged at the communication position; and the controller is used for controlling the operation of the first one-way valve (20) and the second one-way valve (21).

8. The method of claim 7, wherein the superhydrophobic drag-reducing coating is prepared by, The oscillation assembly comprises a second eccentric rod (22) hinged to the top of the second rotating disc (12), and a second sliding rod (23) hinged to the end of the second eccentric rod (22) away from the second rotating disc (12), a limiting rod (28) fixedly connected to the top of the base (1), and the second sliding rod (23) in horizontal sliding fit with the top of the limiting rod (28); the end of the second sliding rod (23) away from the second eccentric rod (22) is fixedly connected with an oscillation box (24), and the oscillation box (24) is in sliding fit with a supporting seat (25) at the bottom, and the bottom of the supporting seat (25) is fixedly connected with the top of the base (1).

9. The method of claim 8, wherein the superhydrophobic drag-reducing coating is prepared by, The fixing assembly comprises a placing groove (26) formed in the top of the base (1), and the placing groove (26) is located below the scraper (16); a plurality of negative pressure holes are formed in the inner bottom wall of the placing groove (26), and the side wall of the base (1) is communicated with a negative pressure pump (27), and the negative pressure holes are all communicated with the negative pressure pump (27); the controller is used for controlling the operation of the negative pressure pump (27), so that the gas at the negative pressure holes is sucked to generate negative pressure, thereby adsorbing and fixing the substrate.

10. The method of claim 9, wherein the superhydrophobic drag-reducing coating is prepared by, The top of the placing groove (26) is conical.

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