Super-hydrophilic coating, preparation method and application of super-hydrophilic coating in slow-release self-repairing and self-cleaning coating

Abstract

The invention discloses a super-hydrophilic coating, a preparation method and application of the super-hydrophilic coating in a slow-release self-repairing and self-cleaning coating. The super-hydrophilic coating is prepared from the following components in parts by mass: 3 to 5 parts of silica sol, 0.03 to 0.15 part of nanotube, 2 to 5 parts of surfactant, 90 to 95 parts of absolute ethyl alcohol, 0.1 to 0.2 part of cyclodextrin, 0.05 to 0.1 part of azobenzene, 3 to 5 parts of tetraethyl orthosilicate, 1 to 2 parts of acetic acid and 1 to 3 parts of modified aluminum dihydrogen phosphate. The self-repairing and self-cleaning agent is applied to a slow-release self-repairing and self-cleaning coating, provides friction resistance in more directions for the coating, greatly improves the durability of the slow-release self-repairing and self-cleaning coating, has good hydrophilicity and transparency, slows down the loss phenomenon of a surfactant of the slow-release self-repairing and self-cleaning coating, improves the film-forming property and uniformity of the coating, and has good application prospects. And the curing agent is suitable for rapid construction, has short curing time, improves the feasibility of large-range construction, and has great application prospects.

Description

Technical Field

[0001] The present invention relates to a superhydrophilic coating, and also relates to a preparation method of the above coating and its application in a slow-release self-repairing and self-cleaning coating. Background Art

[0002] With the continuous popularization and application of photovoltaic power generation technology, the cleaning problem of photovoltaic modules has gradually become prominent. Photovoltaic glass is long-term exposed in open areas, and the environment is often relatively harsh. If the falling substances such as dust adhesion, oily pollutants, and exhaust gas deposition on the surface cannot be cleaned in time, it will not only affect the light transmittance and then reduce the power generation efficiency, but also form hot spots and other problems that will damage the service life of the module. In addition, the surface of automotive glass is prone to be contaminated with dust, resulting in a decrease in visibility. Kitchen utensils are placed in an oily environment for a long time, and oil stains accumulate on the surface area. The blades of wind power generation components are polluted for a long time, resulting in an increase in resistance. All these phenomena have similar problems. Therefore, solving the cleaning problem of the surface of components has practical significance.

[0003] Compared with manual cleaning and mechanical component cleaning, the self-cleaning coating endows the surface with self-cleaning ability, which has the advantages of low cost, resource saving, and good flexibility. However, the current various self-cleaning coatings cannot fully meet the self-cleaning requirements of photovoltaic modules. Superhydrophobic self-cleaning coatings have disadvantages such as low transparency, low cleaning efficiency, and high light scattering rate. Superhydrophilic self-cleaning coatings have disadvantages such as poor durability, poor film-forming property, and complex process. There is an urgent need to develop new self-cleaning coatings. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a superhydrophilic coating, and also relates to a preparation method of the above coating and its application in a slow-release self-repairing and self-cleaning coating.

[0005] Technical Solution: The superhydrophilic coating of the present invention comprises the following components in parts by mass: 3-5 parts of silica sol, 0.03-0.15 parts of nanotubes, 2-5 parts of surfactant, 90-95 parts of absolute ethanol, 0.1-0.2 parts of cyclodextrin, 0.05-0.1 parts of azobenzene, 3-5 parts of tetraethyl orthosilicate, 1-2 parts of acetic acid, 1-3 parts of modified aluminum dihydrogen phosphate.

[0006] The preparation method of the above superhydrophilic coating comprises the following steps:

[0007] (1) Take 3-5 parts by mass of silica sol, 0.03-0.15 parts by mass of nanotubes, and 2-5 parts by mass of surfactant and add them to 90-95 parts by mass of absolute ethanol, and perform vacuum filtration and stirring to obtain a uniformly dispersed solution;

[0008] (2) Add 0.1-0.2 parts by mass of cyclodextrin and 0.05-0.1 parts by mass of azobenzene to the solution in step (1), and stir evenly in a water bath;

[0009] (3) Continuously add 3-5 parts by mass of tetraethyl orthosilicate, 1-2 parts by mass of acetic acid, and 1-3 parts by mass of modified aluminum dihydrogen phosphate to the solution in step (2), and fully stir while heating in a water bath until tetraethyl orthosilicate is completely hydrolyzed to obtain a superhydrophilic coating.

[0010] Among them, in step (1), the silica sol is hollow nano-silica sol; the particle size of the silica sol is 30-40 nm, and the solid content is 8-12%, preferably 10%.

[0011] Among them, in step (1), the nanotube is halloysite; the tube diameter of the nanotube is 10-30 nm, and the tube length is 0.5-2 μm. Due to its special tubular geometry, after the coating is cured, the nanotube can provide greater frictional resistance compared to spherical particles, endowing the coating with better wear resistance. At the same time, the nanotube has a positive charge inside and a negative charge outside, and has a better charge attraction effect with the surfactant. A large amount of surfactant is loaded through the hollow lumen, and the complex geometric shape and charge interaction together slow down the loss phenomenon of the surfactant, greatly improving the durability of the slow-release self-repairing and self-cleaning coating. The surfactant is an anionic surfactant, sodium alkenyl sulfonate.

[0012] Among them, in step (2), cyclodextrin and azobenzene can undergo a cross-linking reaction in the solution to wrap the nano-particle fillers in the coating, further controlling the release rate of the surfactant adsorbed in the hollow particles.

[0013] Among them, in step (3), the preparation method of the modified aluminum dihydrogen phosphate is as follows: Add 100-120 mL of phosphoric acid to 50-100 g of deionized water, stir for 10 min after dilution, then place the obtained diluted phosphoric acid solution in a water bath at 95 °C, and slowly add 10-20 g of aluminum hydroxide and react for 3 h to obtain the inorganic binder aluminum dihydrogen phosphate. The modified aluminum dihydrogen phosphate is aluminum dihydrogen phosphate complexed with metal copper oxide particles. By complexing, a denser aluminum dihydrogen phosphate is formed, which not only better prevents the loss of the surfactant, but also improves the film-forming property and surface flatness of the coating.

[0014] The present invention also discloses the application of the above superhydrophilic coating in a slow-release self-repairing and self-cleaning coating.

[0015] Among them, the preparation method of the slow-release self-repairing and self-cleaning coating is as follows: Activate the surface of the target object after cleaning treatment, spread the coating on the surface and quickly scrape it with a scraping tool to remove the excess coating, and obtain the slow-release self-repairing and self-cleaning coating after curing.

[0016] Among them, for the activation treatment, use a 0.5-1 mol / L sodium hydroxide solution to wipe the surface of the target object back and forth 2-5 times, and then use deionized water to wash the residual alkali solution on the surface.

[0017] Among them, the target object is photovoltaic glass; the thickness of the slow-release self-repairing and self-cleaning coating is 1-3 μm.

[0018] Among them, the curing conditions are normal temperature and the time is 20-40 min.

[0019] Principle of the invention: The superhydrophilic coating of the present invention uses nanotubes with a tube diameter of 10-30 nm and a tube length of 0.5-2 μm as fillers, which form a more compact stack with other particles in the coating, providing frictional resistance in more directions for the coating, greatly improving the durability of the slow-release self-repairing and self-cleaning coating; the surfactant sodium alkenyl sulfonate contains a large number of hydrophilic sulfonic acid groups, making the coating have good superhydrophilicity and self-cleaning function. Tetraethyl orthosilicate is used to crosslink the particles, and modified aluminum dihydrogen phosphate is used as a binder, and the particles are coated and fixed layer by layer through the reaction of azobenzene and cyclodextrin, ensuring the film-forming property and uniformity of the coating, not only slowing down the loss of the surfactant in the slow-release self-repairing and self-cleaning coating, but also improving the film-forming property and uniformity of the coating;

[0020] The slow-release self-repairing and self-cleaning coating prepared by using the superhydrophilic coating of the present invention utilizes the property that water super-spreads on the surface to form a water film, enabling pollutants to float on the water and be carried away by the water flow. The contact angle less than 5° and excellent transparency ensure the light absorption effect of the photovoltaic device, and at the same time have the advantages of simple process and good durability. The superhydrophilic coating obtains a slow-release self-repairing and self-cleaning coating on the surface of photovoltaic glass, which has good hydrophilicity and durability while maintaining good light transmittance. Even under external force damage or water flow erosion, the coating can continuously make up for the surface surfactant lost on the surface by means of the surfactant stored in the particles, making the surface have long-term stable superhydrophilicity, providing a long-term effective self-cleaning effect for photovoltaic glass. In addition, it can also be popularized and applied to fields such as self-cleaning of automotive glass surfaces, oil removal and anti-fouling of kitchenware surfaces, and self-cleaning of wind power generation component blades.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following remarkable advantages: The superhydrophilic coating of the present invention is applied to the slow-release self-repairing and self-cleaning coating. Proven by the Taber abrasion experiment, after the coating is rubbed 400 circles by a CS-10F grinding wheel under a load of 250 g, it still maintains good hydrophilicity, the water contact angle is below 15°, and at the same time has good transparency, the light transmittance is above 89%, and it slows down the loss of the surfactant in the slow-release self-repairing and self-cleaning coating, and also improves the film-forming property and uniformity of the coating; (2) Using the scraping process to form a film has the advantages of simplicity and rapidity compared with processes such as spraying and dipping, which is conducive to rapid construction on the photovoltaic module site, and has a short curing time, improving the feasibility of large-scale construction. Description of the Drawings

[0022] Figure 1 Flow chart for the preparation of the coating in Example 1;

[0023] Figure 2 Water contact angle and transparency effect diagrams of the coating in Example 1; among them, (a) is the water contact angle WCA of the glass coated with the coating in Example 1; (b) is the transparency comparison between the blank glass and the coated glass;

[0024] Figure 3 Self-cleaning effect and underwater oil desorption effect diagrams of the coating in Example 1; among them, (a) is the comparison before and after self-cleaning of the blank glass for dry dust; (b) is the comparison before and after self-cleaning of the coated glass for dry dust; (c) is the comparison before and after self-cleaning of the blank glass for dyed oil; (d) is the comparison before and after self-cleaning of the coated glass for dyed oil; (e) is the comparison before and after underwater oil desorption of the blank glass; (f) is the comparison before and after underwater oil desorption of the coated glass;

[0025] Figure 4 SEM surface morphology diagrams of the coating in Example 1; among them, the magnification of (a), (b), (c), and (d) increases successively, and the microstructure is gradually observed from the surface morphology;

[0026] Figure 5 Physical diagram of the outdoor photovoltaic system components, and the TM200100S solar power generation system provided by Tianming Electric Power, which complies with the standard of GB / T 19064-2003, is selected;

[0027] Figure 6 Power generation gain comparison between the photovoltaic system coated with the slow-release self-repairing self-cleaning coating and the blank control photovoltaic system (from January 1, 2025 to March 31, 2025, a total of 90 days), and the power generation increase rate gradually tends to stabilize at about 20%;

[0028] Figure 7 Water contact angles of the coatings with different halloysite addition amounts in Example 2 after being rubbed 300 circles by a CS-10F grinding wheel under a load of 250 g;

[0029] Figure 8 Water contact angles of the coatings with different alkenyl sulfonate addition amounts in Example 3 after being rubbed 300 circles by a CS-10F grinding wheel under a load of 250 g;

[0030] Figure 9 Reaction mechanism of the isomerization of azobenzene and cyclodextrin;

[0031] Figure 10 Infrared spectra of the coating samples before and after coating;

[0032] Figure 11For the durability comparison between the coating without cyclodextrin and azobenzene in Comparative Example 1 and the coating with both cyclodextrin and azobenzene in Example 1; among them, (a) shows the change of water contact angle with the number of friction cycles under the friction of a CS-10F grinding wheel bearing a load of 250 g; (b) shows the change of water contact angle with the number of friction cycles under the friction of a brush bearing a load of 250 g dipped in water containing a cleaning agent.

[0033] Figure 12 It is a schematic diagram of the modification chemical reaction of binder aluminum dihydrogen phosphate.

[0034] Figure 13 It is a comparison of the solutions before and after the reaction of metal copper oxide particles with aluminum dihydrogen phosphate. The completely reacted solution is in a semi-transparent light blue state.

[0035] Figure 14 It is a SEM surface morphology diagram of the two coatings, with unmodified aluminum dihydrogen phosphate added in Comparative Example 2 and modified aluminum dihydrogen phosphate added in Example 1; among them, (a) is the coating of unmodified aluminum dihydrogen phosphate, and (b) is the coating of modified aluminum dihydrogen phosphate.

[0036] Figure 15 It is the change of water contact angle with the number of friction cycles under the friction of a CS-10F grinding wheel bearing a load of 250 g for the two coatings, with unmodified aluminum dihydrogen phosphate added in Comparative Example 2 and modified aluminum dihydrogen phosphate added in Example 1.

[0037] Figure 16 It is a comparison of the effects after scraping and curing with deionized water as the solvent in Comparative Example 3 and ethanol as the solvent in Example 1. Detailed implementation mode

[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0039] Example 1

[0040] The superhydrophilic coating of the present invention comprises the following components: 4 mL of hollow nano-silica sol, 0.03 g of halloysite, 4 g of alkenyl sulfonate, 90 mL of absolute ethanol, 0.1 g of cyclodextrin, 0.05 g of azobenzene, 4 mL of tetraethyl orthosilicate, 2 mL of acetic acid, and 1.5 mL of modified aluminum dihydrogen phosphate

[0041] Its preparation method is specifically as follows:

[0042] (1) Take 4 mL of hollow nano-silica sol, 0.03 g of halloysite, and 4 g of alkenyl sulfonate, add them to 90 mL of absolute ethanol, and obtain a uniformly dispersed solution after vacuum filtration and stirring;

[0043] (2) Continuously add 0.1 g of cyclodextrin and 0.05 g of azobenzene, and stir in a water bath until uniform;

[0044] (3) Continuously add 4 mL of tetraethyl orthosilicate, 2 mL of acetic acid, and 1.5 mL of modified aluminum dihydrogen phosphate, and fully stir under water bath heating until tetraethyl orthosilicate is completely hydrolyzed to obtain a superhydrophilic coating.

[0045] The surface of the cleaned photovoltaic glass is surface-activated with a 0.5 mol / L sodium hydroxide solution. The superhydrophilic coating is spread on the surface and quickly scraped with a scraping tool with a film thickness parameter of 2 μm to remove the excess coating. After curing at room temperature for 30 min, a slow-release self-repairing and self-cleaning coating with good durability for the photovoltaic glass is formed.

[0046] In Example 1, the surface of the coating is flat, the film-forming property is good, the light transmittance is high, and it has an extremely low initial water contact angle. Figure 2 The water contact angle of the coating shown in (a) is 4.2°. When a water droplet falls on the surface of the coating, it will quickly spread into a water film, showing superhydrophilicity. Figure 2 In (b), the transparency of the blank glass and the coated glass is compared. It can be seen that the self-cleaning coating does not affect the transparency of the glass, ensuring the original high light transmittance of the substrate. The light transmittance of the coated glass is above 89%.

[0047] The coated glass has good self-cleaning effects on both dry dust and oil stains. Figure 3 (a) and (b) show the self-cleaning effects of the blank glass and the coated glass on dry dust. Figure 3 (c) and (d) show the self-cleaning effects of the blank glass and the coated glass on oil stains. Figure 3 (d) and (e) show the underwater oil desorption effects of the blank glass and the coated glass.

[0048] Figure 4 It can be seen from (a) that the microscopic morphology of the coating is extremely flat, indicating that the coating has excellent film-forming properties. The flat surface endows the coating with better hydrophilicity and durability. Figure 4 It can be seen from (c) that the structure of the particles inside the coating is composed of halloysite and silica particles acting as fillers for the coating. The spherical silica particles adhere to the columnar halloysite to form a stable microscopic structure. The particles are fixed by the binder and the hydrolyzed cross-linking agent. A large number of hydrophilic molecules are stored by the hollow nano-silica and halloysite, which plays a very good role in protecting the hydrophilic components of the coating, slowing down the loss of the hydrophilic components in the coating under various damaged conditions, and greatly improving the durability of the coating.

[0049] Wear experiments were conducted on the coated surface layer: The Taber abrasion instrument was used to test the abrasion resistance of the coating. The CS-10F grinding wheel was used, a load of 250 g was applied, and the rotation speed of the abrasion instrument was set at 60 rad / min. After the abrasion, the WCA of the abraded area was measured, and the abrasion resistance of the coating was evaluated by the total number of revolutions in which the abraded area maintained superhydrophilicity.

[0050] Table 1 Content of each element before abrasion

[0051]

[0052] Table 2 Content of each element after abrasion

[0053]

[0054] As shown in Table 1 and Table 2, the comparison of the content of each element before and after abrasion shows that the loss ratio of the hydrophilic component represented by sulfur element is much faster than that of halloysite represented by aluminum element, indicating that halloysite is more stable than the hydrophilic component when the coating is damaged, that is, halloysite plays a greater protective role for the hydrophilic component.

[0055] The self-cleaning coating was applied to the surface of the photovoltaic module, and an outdoor empirical study was carried out for three months. Two photovoltaic cover glasses of the same size were selected. One of them was used as the control group and remained in the original state, and the other experimental group was uniformly coated with the superhydrophilic self-cleaning coating developed in this study by a roller coating device. The treated cover glasses were respectively installed on two photovoltaic power generation systems with the same nominal power, as Figure 5 shown. The test site was selected in an open area with sufficient sunlight and no shading. Key parameters such as the power generation efficiency and component temperature of the two groups of systems were monitored in real time through a data acquisition system. Figure 6 As can be seen, the photovoltaic glass power generation system coated with the superhydrophilic self-cleaning coating showed a significant power generation advantage on the 10th day, and this advantage showed a cumulative growth trend over time. Around the 20th day, the power generation increase rate reached 30%, which was mainly attributed to the frequent rain and fog weather during the same period. The rapid spreading effect of the superhydrophilic coating effectively reduced the scattering loss of water droplets to the incident light. After that, the increase rate stabilized at about 20%, indicating that the self-cleaning function of the coating continued to play a role. Compared with the untreated blank glass, the superhydrophilic coating could maintain the high light transmittance of the photovoltaic glass in the long term by timely removing surface pollutants, thereby ensuring the power generation efficiency.

[0056] Example 2

[0057] The method for forming the slow-release self-repairing self-cleaning coating in Example 2 was exactly the same as that in Example 1, and the only difference was that the addition amount of halloysite was adjusted to 0.01 g, 0.05 g, 0.1 g, and 0.2 g respectively.

[0058] Since adding large particles of halloysite into the hydrophilic coating will cause the solution to be unstable, the addition amount of halloysite is adjusted to optimize the formula. As Figure 7 shown, the formula with a low halloysite content not only effectively improves the sedimentation problem of the solution, but also the wear resistance is higher than that of the formula with a high halloysite content. The stability of the solution makes the coating more uniform and also reduces the roughness of the coating.

[0059] Example 3

[0060] The method for forming the slow-release self-repairing and self-cleaning coating in Example 3 is exactly the same as that in Example 1. The only difference is that the addition amounts of sodium alkenyl sulfonate are adjusted to 2 g, 6 g, 8 g, and 10 g respectively.

[0061] As the addition amount of the surfactant sodium alkenyl sulfonate increases, the durability of the coating tends to improve. As Figure 8 shown, when the addition amount of sodium alkenyl sulfonate is less than 4 wt.%, the increase in the addition amount of sodium alkenyl sulfonate brings a significant improvement in the wear resistance of the coating. However, when the addition amount of sodium alkenyl sulfonate is greater than 4 wt.%, the increase in the addition amount of sodium alkenyl sulfonate does not significantly improve the wear resistance of the coating, indicating that the addition amount of sodium alkenyl sulfonate is close to saturation at this time.

[0062] Comparative Example 1

[0063] A coating, compared with Example 1, does not add cyclodextrin and azobenzene during the preparation process.

[0064] The reaction of cyclodextrin and azobenzene brings further encapsulation and cross-linking between the particles in the coating. The reaction mechanism is as Figure 9 shown, and the infrared spectrogram before the reaction is as Figure 10 shown. The out-of-plane bending vibration peak of C-H in the range of 800 - 700 cm-1 is significantly enhanced, and the characteristic peak at 1600 - 1480 cm-1 shifts. These phenomena indicate that there is a host-guest interaction between the benzene ring in the azobenzene molecule and the cavity of cyclodextrin. As Figure 11 shown, after adding cyclodextrin and azobenzene, the wear resistance and water rubbing resistance of the coating are significantly improved.

[0065] Comparative Example 2

[0066] A coating, compared with Example 1, the added aluminum dihydrogen phosphate is unmodified during the preparation process.

[0067] Aluminum dihydrogen phosphate is a dispersed macromolecule in the solution. Through the use of metal particle complexation, the process is as Figure 12 shown. After complexation, the structure of aluminum dihydrogen phosphate is more compact and the cross-linking density is higher. The aluminum dihydrogen phosphate before and after the reaction is as Figure 13 shown, and the completely reacted solution is in a semi-transparent light blue state. As Figure 14As shown, the coating surface has fewer defects and is smoother, more uniform. As Figure 15 shown, compared with unmodified aluminum dihydrogen phosphate, the wear resistance of the coating made of modified aluminum dihydrogen phosphate has been greatly improved.

[0068] Comparative Example 3

[0069] A coating, compared with Example 1, the solvent was replaced by deionized water during the preparation process.

[0070] As Figure 16 shown, due to the slow evaporation of the superhydrophilic self-cleaning coating with deionized water as the solvent, the curing sequence shows a phenomenon of gathering from the periphery to the center, and finally leaving striped curing marks on the surface, seriously affecting the uniformity and light transmittance of the coating. Therefore, it is concluded that the evaporation rate of the solvent determines the curing rate of the coating. The superhydrophilic self-cleaning coating of the present invention specially selects anhydrous ethanol as the solvent, which has a faster volatility and better dispersibility.

[0071] Therefore, the superhydrophilic coating of the present invention uses nanotubes as filler particles, crosslinks the particles with tetraethyl orthosilicate, uses modified aluminum dihydrogen phosphate as a binder, and uses the reaction of azobenzene and cyclodextrin to layer-by-layer wrap and fix the particles, forming a closer stacking with other particles in the coating, providing more directions of frictional resistance for the coating, and greatly improving the durability of the slow-release self-repairing self-cleaning coating; applied to the slow-release self-repairing self-cleaning coating, the process is simple, and it has good light transmittance, hydrophilicity and durability, providing a long-term effective self-cleaning effect for the surface of objects such as photovoltaic glass, and has great application prospects.

Claims

1. A super hydrophilic coating, characterized in that: The super-hydrophilic coating comprises the following components in parts by mass: 3-5 parts of silica sol, 0.03-0.15 parts of nanotubes, 2-5 parts of surfactants, 90-95 parts of anhydrous ethanol, 0.1-0.2 parts of cyclodextrin, 0.05-0.1 parts of azobenzene, 3-5 parts of tetraethyl orthosilicate, 1-2 parts of acetic acid, and 1-3 parts of modified aluminum dihydrogen phosphate.

2. A method for preparing the super hydrophilic coating according to claim 1, characterized in that: The following steps are involved: (1) adding 3-5 parts by weight of silica sol, 0.03-0.15 parts by weight of nanotubes, and 2-5 parts by weight of a surfactant to 90-95 parts by weight of anhydrous ethanol, vacuum filtering, and stirring to obtain a uniformly dispersed solution; (2) adding 0.1-0.2 parts by weight of cyclodextrin and 0.05-0.1 parts by weight of azobenzene to the solution of step (1), and stirring in a water bath; (3) Continue to add 3-5 parts by weight of tetraethyl orthosilicate, 1-2 parts by weight of acetic acid, and 1-3 parts by weight of modified aluminum dihydrogen phosphate to the solution of step (2), and heat and stir in a water bath until the tetraethyl orthosilicate is completely hydrolyzed to obtain a super hydrophilic coating.

3. The preparation method according to claim 2, characterized in that: In step (1), the silica sol has a particle size of 30-40 nm and a solid content of 8-12%.

4. The preparation method according to claim 2, characterized in that: In step (1), the diameter of the nanotube is 10-30 nm, the length is 0.5-2 μm, and the surfactant is an anionic surfactant sodium olefin sulfonate.

5. The preparation method according to claim 2, characterized in that: In step (3), the modified aluminum dihydrogen phosphate is aluminum dihydrogen phosphate complexed with metal copper oxide particles.

6. Use of the super hydrophilic coating according to claim 1 in a sustained-release self-repairing and self-cleaning coating.

7. The use according to claim 6, characterized in that: The slow-release self-repairing self-cleaning coating is prepared by: activating the surface of the cleaned target object, spreading the coating on the surface and quickly scraping it with a scraping tool, removing excess coating, and obtaining the slow-release self-repairing self-cleaning coating after curing.

8. The use according to claim 7, characterized in that: The activation treatment uses a 0.5-1 mol / L sodium hydroxide solution to wipe the surface of the target object and then uses deionized water to clean the residual alkali solution on the surface.

9. The use according to claim 7, characterized in that: The target object is photovoltaic glass; the slow-release self-repairing and self-cleaning coating has a thickness of 1-3 μm.

10. The use according to claim 7, characterized in that: The curing is carried out at room temperature for 20-40 minutes.

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