Super-hydrophobic emulsion, super-hydrophobic self-cleaning coating, preparation method of super-hydrophobic emulsion and super-hydrophobic self-cleaning coating, and insulator composite structure

Abstract

The invention provides a super-hydrophobic emulsion, a super-hydrophobic self-cleaning coating, a preparation method of the super-hydrophobic emulsion and the super-hydrophobic self-cleaning coating and an insulator composite structure. The preparation method of the super-hydrophobic emulsion comprises the following steps: uniformly mixing an HPMC solution, terpilenol and a SiO2 dispersion liquid to obtain the super-hydrophobic emulsion, wherein the mass ratio of the HPMC to the terpilenol to the SiO2 is (3-7): (60-90): (20-90). The silicon dioxide super-hydrophobic coating is prepared by adopting an efficient fluoride-free method, so that anti-icing application of the surface of a power transmission line insulator is facilitated. The water contact angle of the coating can reach 161 degrees, the sliding angle is smaller than 1 degree, in an anti-icing performance test, the freezing starting time of liquid drops is effectively delayed compared with that of a common surface, and the surface icing amount of the super-hydrophobic coating is reduced by 53.6% compared with that of the common surface. The coating provided by the invention has good corrosion resistance and low temperature resistance, has good anti-icing performance when being applied to the surface of the insulator, and can keep a stable structure.

Description

Technical Field

[0001] The present technology relates to the field of coating technology, and particularly to a superhydrophobic emulsion, a superhydrophobic self-cleaning coating, a preparation method thereof, and an insulator composite structure. Background Art

[0002] As a key component of transmission lines, insulators are often exposed to harsh outdoor environments. Under low-temperature and rain-snow weather conditions, the surface of insulators is prone to icing and ice accumulation, which not only increases the load but also may damage its insulation performance, thereby triggering serious accidents such as insulator flashover, transmission line breakage, and tower collapse. In addition, the dust on the surface of insulators is also likely to cause pollution flashover tripping, posing a threat to the safe operation of power transmission and distribution of the power grid. Current anti-icing and de-icing methods, such as electrothermal method, gas heating method, chemical liquid method, etc., not only cannot completely eliminate the icing hazard but also damage the safety and stability of the equipment itself, and active de-icing measures often require a large amount of manpower, material resources, and financial resources.

[0003] Therefore, there is a need to provide a coating that is resistant to low temperature and corrosion. Summary of the Invention

[0004] To solve the above problems, the present invention provides a superhydrophobic emulsion and a preparation method thereof. The emulsion can form a stable low-surface-energy superhydrophobic coating on a glass substrate or an insulator substrate, which is resistant to low temperature and corrosion.

[0005] Correspondingly, the present invention also provides a superhydrophobic self-cleaning coating prepared by using the above superhydrophobic emulsion and a preparation method thereof. While ensuring the self-cleaning function of the insulator, it can also ensure the low-temperature resistance, anti-icing property, and corrosion resistance of the coating.

[0006] The present invention also provides an insulator composite structure. The coating of the present invention has good corrosion resistance and low-temperature resistance, and has good anti-icing performance and can maintain a stable structure when applied to the surface of the insulator, providing a simple and promising technology for solving the ice prevention problem of insulators.

[0007] To achieve the above object, the following technical solutions are adopted:

[0008] A preparation method of a superhydrophobic emulsion includes the following steps: mixing a HPMC solution and terpineol with a SiO 2 dispersion liquid uniformly to obtain the superhydrophobic emulsion;

[0009] Wherein, the mass ratio of HPMC (powder), terpineol, and SiO 2 is 3-7:60-90:20-90. Preferably, the mass ratio of HPMC, terpineol, and SiO 2 is 3-7:64-90:20-90.

[0010] Preferably, the HPMC solution is obtained by dissolving HPMC in a mixed solvent of ethanol and deionized water, wherein the volume ratio of ethanol to deionized water in the mixed solvent is 1:2 to 7:9. Preferably, the mass percentage of the HPMC solution is 3% to 7%.

[0011] Preferably, the viscosity of the HPMC is 1% to 3%. The inventor found that when preparing the superhydrophobic emulsion, the viscosity of HPMC can affect the coagulation and precipitation of the solution, improving the stability and uniformity of the solution. After research, it was found that the viscosity of HPMC is optimal at 1% to 3%.

[0012] Preferably, the 2 dispersion liquid is obtained by dispersing modified fumed silica nanoparticles in ethanol. More preferably, the mass-volume concentration of the 2 dispersion liquid is 0.02 to 0.09 g / mL.

[0013] Preferably, the particle size of the modified silica nanoparticles is 30 to 40 nm.

[0014] The present invention also provides a superhydrophobic emulsion, which is prepared by using the preparation method of the superhydrophobic emulsion described above; in the superhydrophobic emulsion, the mass ratio of HPMC, terpineol and 2 is 3 to 7:60 to 90:20 to 90.

[0015] A preparation method of a superhydrophobic self-cleaning coating, which comprises the following steps:

[0016] Spray the superhydrophobic emulsion described in claim 6 evenly on the surface of the substrate, and the superhydrophobic self-cleaning coating can be obtained through curing treatment; the curing temperature of the curing treatment is 110 to 125 °C, and the curing time is 2 to 3 h.

[0017] Preferably, the substrate is a glass substrate and / or an insulator.

[0018] The present invention also provides a superhydrophobic self-cleaning coating, the coating thickness of the superhydrophobic self-cleaning coating is 1 to 2 mm, the surface of the coating is a rough structure formed by silica particles alone or in accumulation, wherein the silica particles are ellipsoidal particles. The size of the ellipsoidal particles is 20 nm to 100 nm.

[0019] The present invention also provides an insulator composite structure, which comprises an insulator and a superhydrophobic self-cleaning coating coated on the surface of the insulator.

[0020] Compared with the prior art, the present technology has the following beneficial effects:

[0021] (1) The superhydrophobic emulsion of the present invention can construct a stable low-surface-energy superhydrophobic coating on the surface of a glass substrate or an insulator, which can effectively resist the attachment of moisture, stains, and dust, ensure the long-term cleanliness of the insulator surface, greatly reduce the flashover risk caused by pollution accumulation, and ensure stable power transmission.

[0022] (2) The superhydrophobic self-cleaning coating constructed by the superhydrophobic emulsion of the present invention has a stable structure and performance at low temperatures. It will not fail due to low-temperature embrittlement, maintains good hydrophobicity and self-cleaning ability, and ensures the normal operation of insulators in cold regions.

[0023] (3) The superhydrophobic self-cleaning coating constructed by the superhydrophobic emulsion of the present invention has good corrosion resistance, prevents the surface of the insulator from being eroded and polluted, slows down the aging and damage speed, extends its service life, and reduces the frequency and cost of replacing insulators.

[0024] (4) The present invention uses an efficient and fluorine-free method to prepare a silica superhydrophobic coating to assist in the anti-icing application on the surface of transmission line insulators. The water contact angle of the coating can reach 161°, and the sliding angle is less than 1°. In the anti-icing performance test, the starting freezing time of the liquid droplets is effectively delayed compared with the ordinary surface, and the ice accretion amount on the superhydrophobic coating surface is reduced by 53.6% compared with the ordinary surface. Description of the Drawings

[0025] Figure 1 It is a comparison diagram of the surface contact angle of the superhydrophobic self-cleaning coating prepared in Example 1 of the present invention and the surface contact angle of the uncoated substrate;

[0026] Figure 2 It is a broken line graph of the ice accretion amount on the surface of the substrate of the superhydrophobic self-cleaning coating prepared in Example 1 of the present invention and the uncoated substrate;

[0027] Figure 3 It is a schematic diagram of the ice freezing process of the liquid droplets on the surface of the substrate of the superhydrophobic self-cleaning coating prepared in Example 1 of the present invention and the uncoated substrate;

[0028] Figure 4 It is a comparison graph of the ice accretion process on the surface of the insulator with (bottom) and without (top) the superhydrophobic self-cleaning coating at the same time;

[0029] Figure 5 It is a stability curve graph of the superhydrophobic self-cleaning coating of the present invention in the corrosion solution;

[0030] Figure 6 It is a surface morphology graph of the superhydrophobic self-cleaning coating of the present invention. Detailed Embodiments

[0031] Next, in combination with the accompanying drawings in the embodiments of the present technology, the technical solutions in the embodiments of the present technology will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present technology, rather than all the embodiments. Based on the embodiments in the present technology, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present technology.

[0032] In the embodiments of the present invention, the materials and reagents used are commercially available unless otherwise specified.

[0033] Example 1

[0034] First part, preparation of superhydrophobic aqueous solution:

[0035] (1) Select materials and reagents: anhydrous ethanol (99.7%), terpineol (99%), hydroxypropyl methylcellulose (2% viscosity), and modified silica nanoparticles (30 nm); among them, the modified silica nanoparticles are purchased from Shanghai Aladdin Reagent Co., Ltd.

[0036] (2) Preparation of the solution: Mix ethanol and deionized water in a ratio of 3:5 to form a mixed solvent. While stirring, slowly add hydroxypropyl methylcellulose (HPMC) powder and continuously stir to obtain a 5% mass fraction HPMC solution. Disperse 2.0 g of modified fumed silica (SiO 2 ) into 50 mL of ethanol and stir for 1 h to obtain a SiO 2 dispersion. Dropwise add 10.0 g of the HPMC solution and 8.1 g of terpineol into the SiO 2 dispersion while stirring, and stir for 12 h to obtain a superhydrophobic emulsion (HPMC / SiO 2 solution);

[0037] Second part, construction of a superhydrophobic self-cleaning coating:

[0038] Clean the glass substrate and glass insulator with deionized water and anhydrous ethanol, and dry for later use. Spray the prepared HPMC / SiO 2 solution evenly on the surface of the substrate by spraying method, and cure at 120 °C for 2 h to obtain a HPMC / SiO 2 superhydrophobic self-cleaning coating.

[0039] Example 2

[0040] First part, preparation of superhydrophobic aqueous solution:

[0041] (1) Select materials and reagents: anhydrous ethanol (99.7%), terpineol (99%), hydroxypropyl methylcellulose (3% viscosity), and modified silica nanoparticles (30 nm);

[0042] (2) Preparation of the solution: Mix ethanol and deionized water in a ratio of 7:9 to form a mixed solvent. While stirring, slowly add hydroxypropyl methylcellulose (HPMC) powder and continuously stir to obtain a 5% mass fraction HPMC solution. Disperse 2.0 g of modified fumed silica (SiO 2 ) into 100 mL of ethanol and stir for 1 h to obtain a SiO 2 dispersion. Dropwise add 10.0 g of the HPMC solution and 8.1 g of terpineol into the SiO 2 dispersion while stirring, and stir for 12 h to obtain a superhydrophobic emulsion (HPMC / SiO 2 solution);

[0043] Part Two, construction of the superhydrophobic self-cleaning coating:

[0044] Clean the glass substrate and glass insulator with deionized water and absolute ethanol, and dry for standby. Uniformly spray the prepared HPMC / SiO 2 solution on the surface of the substrate by spraying method, and cure at 120 °C for 2 h to obtain a HPMC / SiO 2 superhydrophobic self-cleaning coating.

[0045] Example Three

[0046] Part One, preparation of the superhydrophobic solution:

[0047] (1) Selection of materials and reagents: absolute ethanol (99.7%), terpineol (99%), hydroxypropyl methylcellulose (3% viscosity), and modified silica nanoparticles (40 nm);

[0048] (2) Preparation of the solution: Mix ethanol and deionized water in a ratio of 7:9 to form a mixed solvent. While stirring, slowly add hydroxypropyl methylcellulose (HPMC) powder and continuously stir to obtain a 3% mass fraction HPMC solution. Disperse 2.0 g of modified fumed silica (SiO 2 ) into 100 mL of ethanol and stir for 1 h to obtain a SiO 2 dispersion. Dropwise add 10.0 g of the HPMC solution and 6.43 g of terpineol into the SiO 2 dispersion while stirring, and stir for 12 h to obtain a superhydrophobic solution (HPMC / SiO 2 solution);

[0049] Part Two, construction of the superhydrophobic self-cleaning coating:

[0050] Clean the glass substrate and glass insulator with deionized water and absolute ethanol, and dry for standby. Uniformly spray the prepared HPMC / SiO 2The solution was evenly sprayed on the surface of the substrate and cured at 110 °C for 3 h to obtain HPMC / SiO 2 superhydrophobic self-cleaning coating.

[0051] Example 4

[0052] First part, preparation of superhydrophobic solution:

[0053] (1) Selection of materials and reagents: anhydrous ethanol (99.7%), terpineol (99%), hydroxypropyl methylcellulose (1% viscosity), and modified silica nanoparticles (40 nm);

[0054] (2) Preparation of the solution: Ethanol and deionized water were mixed in a ratio of 1:2 to form a mixed solvent. While stirring, hydroxypropyl methylcellulose (HPMC) powder was slowly added, and continuous stirring was carried out to obtain a 7% mass fraction HPMC solution. 9.0 g of modified fumed silica (SiO₂) was dispersed in 100 mL of ethanol and stirred for 1 h to obtain SiO 2 dispersion. 10.0 g of the HPMC solution and 8.89 g of terpineol were added dropwise to the SiO 2 dispersion, stirring while adding, and stirring for 12 h to obtain a superhydrophobic solution (HPMC / SiO 2 solution);

[0055] Second part, construction of superhydrophobic self-cleaning coating:

[0056] The glass substrate and glass insulator were cleaned with deionized water and anhydrous ethanol and dried for standby. The prepared HPMC / SiO 2 solution was evenly sprayed on the surface of the substrate by the spraying method and cured at 110 °C for 3 h to obtain HPMC / SiO 2 superhydrophobic self-cleaning coating.

[0057] Example 5

[0058] First part, preparation of superhydrophobic solution:

[0059] (1) Selection of materials and reagents: anhydrous ethanol (99.7%), terpineol (99%), hydroxypropyl methylcellulose (2% viscosity), and modified silica nanoparticles (40 nm);

[0060] (2) Preparation of the solution: Ethanol and deionized water were mixed in a ratio of 1:2 to form a mixed solvent. While stirring, hydroxypropyl methylcellulose (HPMC) powder was slowly added, and continuous stirring was carried out to obtain a 7% mass fraction HPMC solution. 8.0 g of modified fumed silica (SiO 2 ) was dispersed in 100 mL of ethanol and stirred for 1 h to obtain SiO 2Dispersion. 10.0 g of HPMC solution and 7.0 g of terpineol were added dropwise to the SiO 2 dispersion, stirring while adding, and stirring for 12 h to obtain a superhydrophobic aqueous solution (HPMC / SiO 2 solution);

[0061] Second part, constructing a superhydrophobic self-cleaning coating:

[0062] The glass substrate and the glass insulator were cleaned with deionized water and absolute ethanol and dried for standby. The prepared HPMC / SiO 2 solution was evenly sprayed on the surface of the substrate by the spraying method, and cured at 125 °C for 3 h to obtain a HPMC / SiO 2 superhydrophobic self-cleaning coating.

[0063] Testing part:

[0064] Performance characterization test of the superhydrophobic self-cleaning coating:

[0065] (1) Superhydrophobicity: The water contact angle of general superhydrophobic materials is greater than 150°, and the sliding angle is less than 10°. To achieve superhydrophobicity, the material surface should have two characteristics: micro-nano scale rough structure and low surface energy.

[0066] In this embodiment, as shown in Figure 1, the water contact angle of the substrate surface without coating is 41°. After treatment, the contact angle of the substrate surface covered with the superhydrophobic coating reaches 161°, and the rolling angle is less than 1°. The formation of the micro-nano structure in the prepared superhydrophobic coating is realized by modified fumed silica. At the same time, the presence of alkyl groups (i.e., terpineol) provided by the organic components makes the coating have a low surface energy. Hydroxypropyl methylcellulose acts as a binder in the coating, which can improve the adhesiveness of the silica dispersion. After forming the superhydrophobic coating, it can promote the adhesion between silica nanoparticles and form a rough structure at the micro and nano scales. A field emission scanning electron microscope was used to explore the surface morphology of the superhydrophobic coating.

[0067] It can be seen from Figure 6 that uniform ellipsoidal particles are distributed on the surface of the coating, which is a rough structure formed by silica particles alone or in accumulation. The size of the spherical particles ranges from 20 nm to 100 nm, and the formed rough structure is one of the conditions for the formation of the superhydrophobic coating.

[0068] (2) Anti-icing property: At -20 °C, the ice coverage on the surface with and without the silica superhydrophobic coating was studied by comparison. 500 μL of water was poured onto the substrate every 30 min. Then, the mass of the sample was recorded, and the ice coverage on the surface at the same time was compared. From Figure 2It can be seen from the broken line relationship graph that both lines show a linear growth trend. Since it is difficult for droplets to adhere to the surface of the superhydrophobic coating, the droplets quickly bounce off after contacting the surface, resulting in a slow increase in the amount of ice on the coating surface in the first 30 minutes, but normal ice coverage on the uncoated surface. After 3.5 hours, the amount of ice on the uncoated surface was 3.17 g, and the amount of ice on the coated surface was only 1.47 g. In comparison, the amount of ice coverage decreased by 53.6%. The amount of ice coverage on the substrate surface was significantly reduced before and after treatment, indicating that the superhydrophobic coating has a significant effect in reducing the amount of ice coverage on the surface, which is one of the manifestations of the good anti-icing performance of the superhydrophobic coating.

[0069] like Figure 3 As shown, there are obvious differences in the droplet morphology between the coated and uncoated surfaces. The droplets on the uncoated surface spread out quickly on the surface, but the droplets on the coated surface are ellipsoidal. The delay in the freezing process of droplets on the superhydrophobic surface mainly occurs before the phase change, that is, the delay in the start of freezing. The larger water contact angle of the superhydrophobic surface reduces the contact time between the droplets and the surface. In a low-temperature environment, the heat transfer rate between the superhydrophobic coating surface and the droplets is less than the heat transfer rate between the droplets on the uncoated surface, resulting in an extension of the supercooling stage time. As the freezing time increases, the contact line between the droplet and the surface gradually extends along the gas-solid-liquid three-phase interface on the sample surface, and the contact area of ​​the droplet on the surface increases accordingly, which is consistent with the change in the shape of the droplet in the figure. Therefore, the prepared superhydrophobic coating can effectively delay the start of freezing of the droplets, which is another manifestation of the good anti-icing performance of the coating. Furthermore, the freezing process of droplets on the surface of the material can be divided into three stages: the first is the supercooling stage, in which the surface temperature of the water droplets continues to decrease until it is below 0°C; the second is the phase change stage, due to the formation of ice nuclei, the supercooling stage ends and enters the phase change stage, which is a state where solid ice crystals and liquid water coexist; the third is the end of the ice-water mixture state and reaches the complete freezing stage. Figure 3 As shown in the figure, there is a clear difference in the droplet morphology between the coated and uncoated surfaces. The droplets on the uncoated surface spread out quickly on the surface, but the droplets on the coated surface appear ellipsoidal.

[0070] like Figure 4 As shown in the figure, when the surface of the uncoated insulator begins to freeze, the droplets on the coated insulator surface are difficult to adhere to the surface and bounce off due to the effect of the superhydrophobic coating. This is consistent with the results of the icing experiment on the glass substrate. After 150 minutes of the experiment, the longest ice ridge on the uncoated insulator surface was 13.2 cm, and the longest ice ridge on the coated insulator surface was 7.8 cm. The ice layer was distributed in a block-like droplet shape on the surface, forming sparse and discontinuous ice particles with low ice adhesion. Comparing the ice layer states on the two surfaces, the ice layer on the coated surface is easier to fall off and can be easily removed with lower energy input. The above results show that the insulator surface with a superhydrophobic coating exhibits good anti-icing performance.

[0071] (3) Corrosion resistance: The stability of the superhydrophobic coating was tested by simultaneously placing the coated and uncoated glass substrate comparison samples into an acidic solution with pH = 1, a NaCl solution with a mass fraction of 10%, and an alkaline solution with pH = 9. A water contact angle test was performed every 6 h of immersion to determine the hydrophobicity of the surface.

[0072] In this embodiment, as Figure 5 shown, after 36 h of continuous testing, the superhydrophobic coating still maintained good hydrophobicity under the three different corrosive solutions. The pH value of rainwater in the natural state is between 5.6 and 7, and the pH value of light to moderate acid rain is between 4.7 and 5.3. Therefore, the prepared superhydrophobic coating has good stability against the rain state in the natural environment.

[0073] It should be noted that according to the above embodiments of the present technology, those skilled in the art can fully implement the entire scope of the independent claims and dependent claims of the present invention, and the implementation process and method are the same as those in the above embodiments; and the parts not elaborated in detail in the present technology belong to the well-known technology in the art.

[0074] As described above, only some specific embodiments of the present technology are provided, but the protection scope of the present technology is not limited thereto. Any changes or substitutions that can be easily thought of by those familiar with the art within the technical scope disclosed by the present technology should be covered within the protection scope of the present technology.

Claims

1. A method for preparing a super hydrophobic emulsion, characterized in that, The following steps are involved: The super hydrophobic emulsion is obtained by uniformly mixing the HPMC solution, pinene alcohol and SiO2 dispersion; The mass ratio of HPMC, pineol and SiO2 is 3~7:60~90:20~90.

2. The preparation method of super hydrophobic emulsion according to claim 1, characterized in that, The HPMC solution is obtained by dissolving HPMC in a mixed solvent of ethanol and deionized water, wherein the volume ratio of ethanol to deionized water in the mixed solvent is 1:2-7:

9.

3. The preparation method of super hydrophobic emulsion according to claim 1, characterized in that, The viscosity of the HPMC is 1-3%.

4. The preparation method of super hydrophobic emulsion according to claim 1, characterized in that, The SiO2 dispersion is obtained by dispersing modified fumed silica nanoparticles in ethanol.

5. The preparation method of super hydrophobic emulsion according to claim 4, characterized in that, The particle size of the modified silicon dioxide nanoparticles is 30-40 nm.

6. A super hydrophobic emulsion, characterized in that: The super-hydrophobic emulsion is prepared by the preparation method of the super-hydrophobic emulsion according to any one of claims 1 to 5; the mass ratio of HPMC, terpineol and SiO2 in the super-hydrophobic emulsion is 3~7:60~90:20~90.

7. A method for preparing a super hydrophobic self-cleaning coating, characterized in that: The following steps are involved: The super-hydrophobic emulsion according to claim 6 is uniformly sprayed on the surface of the substrate, and the super-hydrophobic self-cleaning coating can be obtained by curing the emulsion; the curing temperature of the curing treatment is 110-125° C., and the curing time is 2-3 h.

8. The method for preparing a super hydrophobic self-cleaning coating according to claim 7, characterized in that: The substrate is a glass substrate and / or an insulator.

9. A super hydrophobic self-cleaning coating, characterized in that: The super hydrophobic self-cleaning coating has a coating thickness of 1 to 2 mm, and the coating surface is a rough structure formed by silicon dioxide particles alone or in piles, wherein the silicon dioxide particles are ellipsoidal particles, and the size of the ellipsoidal particles is 20 nm to 100 nm.

10. An insulator composite structure, characterized in that: The invention comprises an insulator and the super-hydrophobic self-cleaning coating according to claim 9 coated on the surface of the insulator.

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