Preparation method of photo-thermal super-hydrophobic anti-icing composite coating

Abstract

The invention discloses a preparation method of a photo-thermal super-hydrophobic anti-icing composite coating. The preparation method comprises the following steps: dispersing micron-scale particles and nano-scale particles in a solvent, and adding a dispersing agent to obtain a uniform mixture solution; spraying the mixture solution on the surface of a substrate by using a spray gun to obtain the photo-thermal super-hydrophobic anti-icing composite coating; the prepared photo-thermal super-hydrophobic anti-icing composite coating has the characteristics of super hydrophobicity, low adhesion, photo-thermal property, icing resistance and strong mechanical stability. The preparation method is simple, scientific in process, wide in application scene and especially suitable for power transmission lines.

Description

Technical Field

[0001] The present invention belongs to the field of material technology, and specifically relates to a method for preparing a photothermal super-hydrophobic anti-icing coating. Background Art

[0002] Transmission lines are susceptible to ice. If there is too much ice on the transmission lines, it often causes uneven and unbalanced conductor loads, leading to accidents such as transmission line dancing, line breakage and tower collapse, which has a great impact on the safety of the power grid. In nature, the formation and accumulation of ice is a very common phenomenon. Traditional deicing methods include mechanical deicing, electric heating deicing, manual deicing, microwave deicing, etc., but these technologies have the problems of high cost and low efficiency. Chemical deicing agent deicing technology is an effective deicing method. Although it can reduce the melting point of ice and snow to achieve the purpose of deicing, its damage to the environment cannot be ignored. In comparison, the preparation of anti-icing coatings by spraying is simple and low-cost, and is more suitable for large-scale promotion. It has been widely reported that superhydrophobic coatings are used for anti-icing on material surfaces. The superhydrophobic properties of the coating enable the material surface to reduce the adhesion of liquids on its surface and increase the bouncing of liquids on its surface. At the same time, after the liquid freezes, due to its small contact area, the ice can easily detach from its surface. In addition, the photothermal effect can promote the melting of ice on the surface of the material in a low-temperature environment, thereby achieving active deicing performance. Summary of the invention

[0003] In order to overcome the deficiencies and shortcomings of the prior art, the object of the present invention is to provide a method for preparing a photothermal super-hydrophobic anti-icing composite coating. The photothermal super-hydrophobic anti-icing composite coating prepared by this method overcomes the problems of insufficient mechanical resistance, lack of corrosion resistance, and poor photothermal performance of existing super-hydrophobic anti-icing coatings in harsh environments.

[0004] The technical solution of the present invention is a method for preparing a photothermal super-hydrophobic anti-icing composite coating, comprising the following steps:

[0005] Step 1, preparation of substrate: firstly, use 2000-grit sandpaper to polish the aluminum sheet, put the polished aluminum sheet into anhydrous ethanol for ultrasonic cleaning, then take it out and dry it to obtain a spraying substrate;

[0006] Step 2, preparation of a mixed spray solution: nano-silicon dioxide, carbon nanotubes, and ethyl acetate are mixed in a mass volume ratio of 0.5-2 g: 0.5-2 g: 10-40 ml, magnetically stirred, and ultrasonically treated to obtain a uniformly dispersed mixed spray solution;

[0007] Step 3, treatment of the mixed spray solution: adding 1 g of polydimethylsiloxyamine and 0.6 g of epoxy resin to the mixed spray solution prepared in step 2, then adding a curing agent, stirring with a magnetic force, obtaining a uniformly dispersed viscous solution, and loading into a spray gun;

[0008] Step 4, preparation of a super-hydrophobic anti-icing coating: using a spray gun to vertically spray the viscous solution obtained in step 3 onto the substrate in step 1 to obtain a super-hydrophobic anti-icing coating;

[0009] Step 5, preparation of a photothermal super-hydrophobic anti-icing composite coating: placing the super-hydrophobic anti-icing coating obtained in step 4 in an oven, and heating it to obtain a completely cured photothermal super-hydrophobic anti-icing composite coating with low surface energy attached to the surface.

[0010] Furthermore, the ultrasonic cleaning time in step 1 is 10 minutes.

[0011] Furthermore, in step 2, the diameter of the carbon nanotubes is 8 to 15 nm, and the length is 3 to 12 μm.

[0012] Furthermore, the diameter of the nano-silica in step 2 is 50 um.

[0013] Furthermore, in step 2, the magnetic stirring speed is 800 r / min and the time is 0.5 h.

[0014] Furthermore, the ultrasonic treatment in step 2 is performed for 5 minutes.

[0015] Furthermore, in step 3, the magnetic stirring speed is 1200 r / min and the time is 1 h.

[0016] Furthermore, in step 3, the ratio of polydimethylsiloxane to curing agent is 10:1; the ratio of epoxy resin to curing agent is 1:1.

[0017] Furthermore, in the spraying process in step 4, the vertical distance between the spray gun and the substrate is 10 cm; the spray gun pressure is 0.2-0.3 MPa, and the flow rate is 40 mL / min.

[0018] Furthermore, in step 5, the oven temperature is 80-100° C. and the heating time is 1 hour.

[0019] The present invention has the following beneficial effects

[0020] 1. The preparation method uses a spraying method to evenly spray the mixture solution on the surface of the substrate, so that the carbon nanotubes (MCNTs) are stably present in the entire coating system network to construct an efficient photothermal anti-icing composite coating.

[0021] 2. The sprayed mixed solution uses polydimethylsiloxane (PDMS) and epoxy resin (EP) as adhesives to improve the adhesion between micro-nanoparticles and reduce the agglomeration of micro-nanoparticles during the spraying process.

[0022] 3. The obtained coating has excellent superhydrophobicity, which greatly reduces the contact area of ​​water on the coating surface, causing droplets to easily slide off its surface and prolonging the freezing time of water.

[0023] 4. Low surface energy and micro-nano surface roughness make water form less ice adhesion in low temperature environment. Under simulated sunlight, the stable coating structure makes the photothermal effect more efficient in promoting the melting of ice on its surface, so that the ice layer on the coating surface slides off and the droplets melt.

[0024] 5. The coating combines the passive anti-icing performance of the micro-nano structure and the active deicing performance of the photothermal effect, and has the advantages of mechanical stability, strong corrosion resistance, and simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a contact angle measurement diagram of Example 1 of the present invention;

[0026] Figure 2 This is a contact angle measurement diagram of Example 2 of the present invention;

[0027] Figure 3 This is a contact angle measurement diagram of Example 3 of the present invention;

[0028] Figure 4 It is a flow chart of the preparation method of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0030] The test conditions involved in the following examples are as follows: water contact angle and rolling angle are measured by surface tension surface contact angle tester; ice adhesion and freezing delay time are measured in a climate chamber (-20℃, 30RH%). The ice adhesion test platform is composed of a tensile sensor, and its value is the maximum value of the sensor in the process of removing ice. The freezing delay time is the time required for a single water droplet to completely freeze from the liquid state to the coating surface, and the process is completed by a CCD industrial camera. The photothermal performance is generated by a solar simulator, and the infrared measuring instrument records the surface temperature change of the sample.

[0031] Example 1: Figure 2 As shown, this embodiment discloses a method for preparing a photothermal super-hydrophobic anti-icing composite coating, comprising the following implementation steps:

[0032] Step 1, preparation of the spray substrate: first, use 2000-grit sandpaper to polish the aluminum sheet, place the polished aluminum sheet in anhydrous ethanol for ultrasonic cleaning (10 minutes), then take it out and dry it to obtain the spray substrate;

[0033] Step 2, preparation of a mixed spray solution: 1 g of silicon dioxide, 0.7 g of carbon nanotubes and 40 ml of ethyl acetate were mixed, magnetically stirred (800 r / min, time for 0.5 h), and ultrasonically treated (5 min) to obtain a uniformly dispersed mixed spray solution;

[0034] Step 3, treatment of the mixed spray solution: add 1g of polydimethylsiloxane and 0.6g of epoxy resin to the mixed spray solution prepared in step 2, then add 0.1g of polydimethylsiloxane curing agent (manufactured by Dow Corning, USA) and 0.6g of epoxy resin curing agent (manufactured by Nanchang Chenfang Adhesive Products Co., Ltd.), stir magnetically (1200r / min, time is 1h), obtain a uniformly dispersed viscous solution, and load it into the spray gun; due to the use of a low surface energy adhesive, the overall stability of the coating is greatly improved;

[0035] Step 4, preparation of a super-hydrophobic anti-icing composite coating: vertically spraying the viscous solution obtained in step 2 onto the substrate in step 1 to obtain a super-hydrophobic anti-icing composite coating, wherein the spray gun pressure is 0.3 MPa and the flow rate is 40 mL / min;

[0036] Step 5, prepare a photothermal super-hydrophobic anti-icing composite coating: place the super-hydrophobic anti-icing composite coating obtained in step 4 in an oven (100°C, heating time is 1h), and after heating, a completely cured photothermal super-hydrophobic anti-icing composite coating with low surface energy attached to the surface is obtained.

[0037] Example 2: Figure 2 As shown, this embodiment discloses a method for preparing a photothermal super-hydrophobic anti-icing composite coating, comprising the following implementation steps:

[0038] Step 1, preparation of the spray substrate: first, use 2000-grit sandpaper to polish the aluminum sheet, place the polished aluminum sheet in anhydrous ethanol for ultrasonic cleaning (10 minutes), then take it out and dry it to obtain the spray substrate;

[0039] Step 2, preparation of a mixed spray solution: 1 g of silicon dioxide, 0.7 g of carbon nanotubes and 40 ml of ethyl acetate were mixed, magnetically stirred (800 r / min, time for 0.5 h), and ultrasonically treated (5 min) to obtain a uniformly dispersed mixed spray solution;

[0040] Step 3, treatment of the mixed spray solution: add 1.5g of polydimethylsiloxane and 0.6g of epoxy resin to the mixed spray solution prepared in step 2, then add 0.15g of polydimethylsiloxane curing agent (manufactured by Dow Corning, USA) and 0.6g of epoxy resin curing agent (manufactured by Nanchang Chenfang Adhesive Products Co., Ltd.), stir magnetically (1200r / min, time is 1h), obtain a uniformly dispersed viscous solution, and load it into the spray gun; due to the use of a low surface energy adhesive, the overall stability of the coating is greatly improved;

[0041] Step 4, preparation of a super-hydrophobic anti-icing composite coating: vertically spraying the viscous solution obtained in step 2 onto the substrate in step 1 to obtain a super-hydrophobic anti-icing composite coating, wherein the spray gun pressure is 0.3 MPa and the flow rate is 40 mL / min;

[0042] Step 5, prepare a photothermal super-hydrophobic anti-icing composite coating: place the super-hydrophobic anti-icing composite coating obtained in step 4 in an oven (100°C, heating time is 1h), and after heating, a completely cured photothermal super-hydrophobic anti-icing composite coating with low surface energy attached to the surface is obtained.

[0043] Example 3: Figure 2 As shown, this embodiment discloses a method for preparing a photothermal super-hydrophobic anti-icing composite coating, comprising the following implementation steps:

[0044] Step 1, preparation of the spray substrate: first, use 2000-grit sandpaper to polish the aluminum sheet, place the polished aluminum sheet in anhydrous ethanol for ultrasonic cleaning (10 minutes), then take it out and dry it to obtain the spray substrate;

[0045] Step 2, preparation of a mixed spray solution: 1 g, 1.5 g, and 40 ml of silica, carbon nanotubes, and ethyl acetate were mixed, magnetically stirred (800 r / min, time for 0.5 h), and ultrasonically treated (5 min) to obtain a uniformly dispersed mixed spray solution;

[0046] Step 3, treatment of the mixed spray solution: add 1g of polydimethylsiloxane and 1g of epoxy resin to the mixed spray solution prepared in step 2, then add 0.1g of polydimethylsiloxane curing agent (manufacturer is Dow Corning Corporation of the United States) and 1g of epoxy resin curing agent (manufacturer is Nanchang Chenfang Adhesive Products Co., Ltd.), and stir magnetically (1200r / min, time is 1h) to obtain a uniformly dispersed viscous solution, which is loaded into a spray gun; due to the use of a low surface energy adhesive, the overall stability of the coating is greatly improved;

[0047] Step 4, preparation of a super-hydrophobic anti-icing composite coating: vertically spraying the viscous solution obtained in step 2 onto the substrate in step 1 to obtain a super-hydrophobic anti-icing composite coating, wherein the spray gun pressure is 0.3 MPa and the flow rate is 40 mL / min;

[0048] Step 5, prepare a photothermal super-hydrophobic anti-icing composite coating: place the super-hydrophobic anti-icing composite coating obtained in step 4 in an oven (100°C, heating time is 1h), and after heating, a completely cured photothermal super-hydrophobic anti-icing composite coating with low surface energy attached to the surface is obtained.

[0049] The present invention obtains a super-hydrophobic coating by spraying it on the surface of a substrate with a room temperature spray gun; a stable photothermal responsive super-hydrophobic anti-icing composite coating is obtained through heat treatment. The preparation method is simple, the process is scientific, and the application scenarios are wide, especially suitable for transmission lines.

[0050] After heat treatment and low surface energy treatment, the coating prepared by the present invention contains a stable micro-nano multi-level structure. Through the multi-level structure, the coating has super-hydrophobic and low-adhesion properties. MCNTs construct a continuous grid structure, so that the entire coating surface can exert more excellent photothermal properties, so that the coating can melt frozen water droplets and ice on the surface under the irradiation of light source.

[0051] Under the thermal effect, the micro-nano structure on the coating surface forms a continuous grid, and remains super-hydrophobic after linear friction with sandpaper, gravel impact and chemical erosion tests. Combined with the coating's own super-hydrophobic passive anti-icing properties and the photothermal effect passive anti-icing properties, the entire coating has reliable firmness and enhanced durability.

[0052] Comparative Example 1, using untreated aluminum sheet as a comparison, the results are shown in Table 1 below:

[0053] Table 1: Coating sample performance test results

[0054] sample Hydrophobic angle / ° Sliding angle / ° Freezing delay time / s Ice adhesion / kPa Temperature after 5 minutes of illumination / ℃ Example 1 152.715 6 341.8 15.7 65.4 Example 2 132.671 10 208.3 30.1 66.2 Example 3 115.352 18 155.6 60.5 65.7 Comparative Example 1 72.351 / 28.7 153.1 36.9

[0055] The above is only a specific implementation of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Any changes or substitutions that can be easily thought of by any technician familiar with the field within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a photothermal super-hydrophobic anti-icing composite coating, characterized in that: The steps include: (1) Preparation of substrate: First, use 2000-grit sandpaper to polish the aluminum sheet, place the polished aluminum sheet in anhydrous ethanol for ultrasonic cleaning, and then take it out and dry it to obtain a spray-coated substrate; (2) Preparation of a mixed spray solution: nano-silicon dioxide, carbon nanotubes, and ethyl acetate are mixed in a mass volume ratio of 0.5-2 g: 0.5-2 g: 10-40 ml, magnetically stirred, and ultrasonically treated to obtain a uniformly dispersed mixed spray solution; (3) Treatment of the mixed spray solution: 1 g of polydimethylsiloxane and 0.6 g of epoxy resin are added to the mixed spray solution prepared in step (2), and then a curing agent is added. The mixture is stirred by magnetic force to obtain a uniformly dispersed viscous solution, which is then loaded into a spray gun; (4) Preparation of a super-hydrophobic anti-icing coating: spraying the viscous solution obtained in step (3) vertically onto a substrate using a spray gun to obtain a super-hydrophobic anti-icing coating; (5) Preparation of a photothermal super-hydrophobic anti-icing composite coating: The super-hydrophobic anti-icing coating obtained in step (4) is placed in an oven and heated to obtain a completely cured photothermal super-hydrophobic anti-icing composite coating with low surface energy.

2. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: The ultrasonic cleaning time in step 1 is 10 minutes.

3. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: In step 2, the diameter of the carbon nanotubes is 8 to 15 nm, and the length is 3 to 12 μm.

4. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: The diameter of the nano-silicon dioxide in step 2 is 50 um.

5. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: In step 2, the magnetic stirring speed is 800 r / min and the time is 0.5 h.

6. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: The ultrasonic treatment in step 2 is performed for 5 min.

7. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: In step 3, the ratio of polydimethylsiloxane to curing agent is 10:1; the ratio of epoxy resin to curing agent is 1:

1.

8. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: In step 3, the magnetic stirring speed is 1200 r / min and the time is 1 h.

9. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: During the spraying process in step 4, the vertical distance between the spray gun and the substrate is 10 cm; the spray gun pressure is 0.2-0.3 MPa, and the flow rate is 40 mL / min.

10. The method for preparing the photothermal super-hydrophobic anti-icing composite coating according to claim 1, characterized in that: In step 5, the oven temperature is 80-100° C. and the heating time is 1 hour.

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