A super-hydrophilic nano-coating for photovoltaic glass, its preparation method and application

Abstract

The present invention discloses a superhydrophilic nano-coating for photovoltaic glass, its preparation method and application, which includes 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, 6-11 parts by weight of isopropanol, 10-15 parts by weight of absolute ethanol, 0.1-0.2 parts by weight of propylene glycol block polyether, 0.1-0.15 parts by weight of wetting agent, and 0.2-0.4 parts by weight of leveling agent. The suspension in the superhydrophilic nano-coating for photovoltaic glass is mainly chain-like silica nanoparticles. This coating can be applied to the surface of photovoltaic glass to form a superhydrophilic nano-coating, effectively improving properties such as light transmittance, anti-static, anti-fog, anti-fouling and self-cleaning, and ultimately increasing the power generation of photovoltaic modules.

Description

Technical Field

[0001] The present invention relates to the field of new energy materials, and particularly to a super-hydrophilic nano-coating for photovoltaic glass, its preparation method and application. Background Art

[0002] As one of the most promising renewable clean energies in the 21st century, solar photovoltaic power generation has attracted wide attention. According to statistics, as of the end of 2023, the installed capacity of solar power generation in the country was approximately 609.49 GW, a year-on-year increase of 55.2%, accounting for half of the total global photovoltaic installed capacity. This also shows that solar photovoltaic power generation in China has broad development prospects.

[0003] Since solar photovoltaic glass panels are exposed to the outdoors for a long time, and the components of various pollutants in the air are complex, with a high ratio of organic pollutants, and organic pollutants have strong adhesion ability, various dust, grease and other organic substances are likely to accumulate on the surface of photovoltaic glass, affecting the light transmittance of the photovoltaic glass panel, resulting in IMA loss and fouling loss. The IMA loss and fouling loss can account for up to 35.5% of the total efficiency loss. Therefore, the photovoltaic glass panel needs to be cleaned several times a year, and the annual cleaning of pollutants will lead to an increase in cost.

[0004] Therefore, it is of great practical significance to develop a coating with self-cleaning, anti-reflection and light transmittance enhancement and other properties and apply it to the surface of photovoltaic glass panels to improve the power generation of solar photovoltaics. Summary of the Invention

[0005] The purpose of the present invention is to provide a super-hydrophilic nano-coating for photovoltaic glass, its preparation method and application. After coating this coating on photovoltaic glass, it can greatly improve the surface wetting, light transmittance, anti-static, anti-fog, anti-fouling and self-cleaning and other properties of photovoltaic glass, reduce the pollution of photovoltaic glass, thereby improving the light transmittance of photovoltaic glass, increasing power generation and reducing cleaning costs.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a super-hydrophilic nano-coating for photovoltaic glass, which is made of the following chemical components in parts by weight: 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, 6-11 parts by weight of isopropanol, 10-15 parts by weight of absolute ethanol, 0.1-0.2 parts by weight of propylene glycol block polyether, 0.1-0.15 parts by weight of wetting agent, 0.2-0.4 parts by weight of leveling agent;

[0007] The method for preparing the super-hydrophilic nano-coating for photovoltaic glass is as follows:

[0008] (1) Place 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, and 6-11 parts by weight of isopropyl alcohol in a constant-temperature glass reaction kettle at 35°C, and continuously stir at a rotation speed of 300-400 rpm for 30-60 min;

[0009] (2) Add an alkaline pH regulator until the pH of the solution is adjusted to between 9.5 and 10, and continue stirring for 60-120 min;

[0010] (3) Add 0.1-0.2 parts by weight of propylene glycol block polyether, and continue stirring for 30-60 min;

[0011] (4) Add an acidic pH regulator until the pH of the solution is adjusted to between 7 and 7.5, and continue stirring for 120-180 min;

[0012] (5) Add 10-15 parts by weight of absolute ethanol, 0.1-0.15 parts by weight of wetting agent, and 0.2-0.4 parts by weight of leveling agent respectively, and then add an acidic pH regulator until the pH of the solution is adjusted to between 2 and 4, and continue stirring for 60-90 min to obtain the super-hydrophilic nano-coating for photovoltaic glass described above;

[0013] The suspended matter generated in the super-hydrophilic nano-coating for photovoltaic glass described above is mainly chain-like silica nanoparticles.

[0014] Further, for the super-hydrophilic nano-coating for photovoltaic glass described above, the average particle size of the chain-like silica nanoparticles is 25-100 nm.

[0015] Further, for the super-hydrophilic nano-coating for photovoltaic glass described above, the wetting agent is one or more non-ionic surfactants such as alkylphenol polyoxyethylene ether, higher fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene amine, polyoxyethylene amide, fatty acid ethylene glycol ester, monoglyceride fatty acid, sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene copolymer, and fatty acid alkanolamide.

[0016] Further, for the super-hydrophilic nano-coating for photovoltaic glass described above, the leveling agent is one or more silicone-based leveling agents such as polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, and reactive functional group-modified polydimethylsiloxane.

[0017] A preparation method of a super-hydrophilic nano-coating for photovoltaic glass is as follows:

[0018] (1) Place 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, and 6-11 parts by weight of isopropyl alcohol in a constant-temperature glass reaction kettle at 35°C, and continuously stir at a speed of 300-400 rpm for 30-60 min;

[0019] (2) Add an alkaline pH regulator until the pH of the solution is adjusted to between 9.5 and 10, and continue stirring for 60-120 min;

[0020] (3) Add 0.1-0.2 parts by weight of propylene glycol block polyether, and continue stirring for 30-60 min;

[0021] (4) Add an acidic pH regulator until the pH of the solution is adjusted to between 7 and 7.5, and continue stirring for 120-180 min;

[0022] (5) Add 10-15 parts by weight of absolute ethanol, 0.1-0.15 parts by weight of wetting agent, and 0.2-0.4 parts by weight of leveling agent respectively, and then add an acidic pH regulator to adjust the pH of the solution to between 2 and 4, and continue stirring for 60-90 min to obtain the super-hydrophilic nano-coating for photovoltaic glass.

[0023] Further, in the preparation method of the super-hydrophilic nano-coating for photovoltaic glass described above, the alkaline pH regulator is a mixed solution of ammonia water and absolute ethanol with a mass ratio of 1:99.

[0024] Further, in the preparation method of the super-hydrophilic nano-coating for photovoltaic glass described above, the acidic pH regulator is a mixed solution of glacial acetic acid and absolute ethanol with a mass ratio of 1:99.

[0025] An application of the super-hydrophilic nano-coating for photovoltaic glass. The application method is: coat the super-hydrophilic nano-coating for photovoltaic glass on the front surface of the photovoltaic glass, and after curing at room temperature for 30-60 min, a super-hydrophilic nano-coating can be formed on the front surface of the photovoltaic glass. The thickness of the cured super-hydrophilic nano-coating is 150-250 nm.

[0026] Further, the water contact angle of the photovoltaic glass after coating treatment is less than 5°.

[0027] Further, compared with the photovoltaic glass without coating, the light transmittance of the photovoltaic glass after coating treatment is increased by 1-3%.

[0028] The advantages of the present invention are as follows: The suspended substances in the super-hydrophilic nano-coating for photovoltaic glass of the present invention are mainly chain-like silica nanoparticles. The chain-like silica nanoparticles are covalently bonded through propylene glycol block polyether to form a one-dimensional or multi-dimensional chain-like structure. This structure significantly increases the surface roughness and specific surface area of the particles. The increase in surface roughness helps to improve the surface wettability, thereby enhancing the hydrophilicity. The increase in specific surface area provides more active sites and capillary pores. These capillary pores can rapidly absorb and disperse moisture through capillary condensation, thereby further enhancing the hydrophilicity of the coating. The super-hydrophilic nano-coating for photovoltaic glass of the present invention is applied to the surface of photovoltaic glass by spraying, brushing, dipping and other techniques, and after curing for 30 - 60 minutes, a super-hydrophilic nano-coating can be formed on the surface of photovoltaic glass. The photovoltaic glass after coating treatment has super-hydrophilicity, the water contact angle is less than 5°, the light transmittance is increased by 1% - 3%, and after using the coated photovoltaic glass in the photovoltaic string, the total annual power generation is increased by more than 5%. Description of the Drawings

[0029] Figure 1 It is a TEM diagram of the super-hydrophilic nano-coating for photovoltaic glass described in Embodiments 1 - 3 of the present invention.

[0030] Figure 2 It is a SEM diagram of the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Embodiments 1 - 3 of the present invention.

[0031] Figure 3 It is an AFM diagram of the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Embodiments 1 - 3 of the present invention.

[0032] Figure 4 It is an FT-IR diagram of the super-hydrophilic nano-coating formed by using the super-hydrophilic nano-coating for photovoltaic glass described in Embodiment 4 of the present invention.

[0033] Figure 5 It is a comparison diagram of the light transmittance between the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Embodiment 4 of the present invention and the uncoated photovoltaic glass.

[0034] Figure 6 It is a comparison group diagram of the water contact angle between the surface of the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Embodiments 1 - 4 of the present invention and the surface of the uncoated photovoltaic glass. In each group of diagrams, the photovoltaic glass located above is not coated with the coating.

[0035] Figure 7It is a test comparison group diagram of the antistatic performance between the surface of a photovoltaic glass coated with a superhydrophilic nano-coating for photovoltaic glass described in Embodiments 1-4 of the present invention and the surface of a photovoltaic glass without the coated coating. In each group of diagrams, the photovoltaic glass on the left side is not coated with the coating.

[0036] Figure 8 It is a test comparison diagram of the antifouling and self-cleaning performance of the surface of a photovoltaic glass coated with a superhydrophilic nano-coating for photovoltaic glass described in Embodiments 1-4 of the present invention. In each diagram, the left half area of the photovoltaic glass is not coated with the coating. Specific embodiments

[0037] A superhydrophilic nano-coating for photovoltaic glass is made of the following chemical components in parts by weight: 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, 6-11 parts by weight of isopropanol, 10-15 parts by weight of absolute ethanol, 0.1-0.2 parts by weight of propylene glycol block polyether, 0.1-0.15 parts by weight of a wetting agent. The wetting agent is one or more non-ionic surfactants among alkylphenol polyoxyethylene ether, high-carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene amine, polyoxyethylene amide, fatty acid ethylene glycol ester, monoglyceride fatty acid ester, sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene copolymer, fatty acid alkanolamide. Using non-ionic surfactants can reduce the surface tension of the coating, and non-ionic surfactants have both hydrophobic and hydrophilic groups at the same time, which can form a strong chemical bond between the substrate and the coating, thereby enhancing the adhesion of the coating and enabling the coating to spread evenly on the substrate surface. 0.2-0.4 parts by weight of a leveling agent. The leveling agent is one or more silicone-based leveling agents among polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, organically modified polydimethylsiloxane, and polydimethylsiloxane modified with reactive functional groups. Silicone-based leveling agents can provide better fluidity by changing the surface state of the coating, making the coating smoother and more uniform, eliminating various coating defects caused by surface tension differences, and silicone-based leveling agents have good high-temperature and ultraviolet resistance, which can protect the coating from aging easily in harsh environments and extend its service life.

[0038] The preparation method of the superhydrophilic nano-coating for photovoltaic glass is as follows:

[0039] (1) Place 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, and 6-11 parts by weight of isopropanol in a constant-temperature glass reactor at 35 °C, and continuously stir at a speed of 300-400 rpm for 30-60 min. Tetraethyl orthosilicate reacts with deionized water to form silicic acid and ethanol. During this process, since tetraethyl orthosilicate is not easily soluble in water at room temperature, a co-solvent isopropanol needs to be added to form a homogeneous reaction system. Condensation occurs between the hydrolyzed silicic acids or between silicic acid and unreacted tetraethyl orthosilicate, ultimately forming a silica sol. During this process, the hydrolysis and condensation reactions are relatively slow, so the reaction needs to be carried out under catalytic conditions;

[0040] (2) Add an alkaline pH regulator until the pH of the solution is adjusted to between 9.5 and 10, and continue stirring for 60-120 min. Under base catalysis, the silicic acid produced by the hydrolysis reaction has more negative charges, making it easier to undergo condensation reactions with other silicic acids or tetraethyl orthosilicate, thereby enhancing the hydrolysis and condensation reaction rates of tetraethyl orthosilicate and quickly obtaining a sol. When the reaction is carried out under alkaline conditions, the hydrolysis of tetraethyl orthosilicate is relatively complete. At the same time as hydrolysis, polycondensation reactions occur between the hydrolysis intermediate products. Due to steric hindrance effects, the polymerization rate is relatively slow, and the resulting sol is relatively stable and not easily gelled;

[0041] (3) Add 0.1-0.2 parts by weight of propylene glycol block polyether and continue stirring for 30-60 min. This solvent has excellent solubilization, emulsification, demulsification, defoaming, dispersion, wetting, penetration, lubrication, and antistatic capabilities. Its main function is to crosslink the nano-silica particles in the silica sol into chain-like silica nanoparticles, and the average particle size of the chain-like silica nanoparticles is 25-100 nm; the chain-like silica nanoparticles are connected by covalent bonds to form a one-dimensional or multi-dimensional chain-like structure. This structure significantly increases the surface roughness and specific surface area of the particles. The increase in surface roughness helps to improve the surface wettability, thereby enhancing hydrophilicity, while the increase in specific surface area provides more active sites and capillary pores. These capillary pores can quickly absorb and disperse water through capillary condensation, thereby further enhancing the hydrophilicity of the coating; the silica particles in the chain-like structure are combined with propylene glycol block polyether by covalent bonds, and their binding force is far superior to the electrostatic force or van der Waals force between silica nanoparticles. This not only effectively improves the mechanical properties of the coating but also greatly improves the antistatic properties of the coating.

[0042] (4) Add an acidic pH regulator until the pH value of the solution is adjusted to between 7 and 7.5, and continue stirring for 120-180 min. In a neutral environment, the reaction activity between the remaining reactants and products is relatively low, which is conducive to achieving chemical equilibrium, thereby reducing further uncontrollable reactions;

[0043] (5) Add 10 - 15 parts by weight of absolute ethanol, 0.1 - 0.15 parts by weight of wetting agent, and 0.2 - 0.4 parts by weight of leveling agent respectively. Adding absolute ethanol, wetting agent and leveling agent can improve the fluidity and covering effect of the coating, enabling it to be more evenly distributed on the substrate. Then add an acidic pH regulator to adjust the pH of the solution to between 2 and 4, and continue stirring for 60 - 90 min to obtain a superhydrophilic nano - coating for photovoltaic glass. Adjusting the solution to an acidic condition can form a dense coating film during the drying process, which is beneficial to improving the adhesion and durability of the coating film, enabling its performance to remain unchanged for a long time and extending the service life of the coating.

[0044] In this embodiment, in steps (2), (4) and (5), the solution is relatively sensitive to changes in pH. If the acid - base change is too fast, it will cause the solution structure to be unstable. In order to precisely control the pH value of the solution, a PID (Proportional - Integral - Derivative) control strategy is adopted in this embodiment. The PID algorithm can adjust the dosing speed of the peristaltic pump according to the deviation magnitude and change rate of the pH value, so as to quickly and stably adjust the pH value to the target range. For example, when preparing 50 L of the coating, the dosing rates of the alkaline pH regulator and the acidic pH regulator can be calculated by the PID algorithm to be 6 - 8 mL / min.

[0045] In this embodiment, in step (2), the alkaline pH regulator is a mixed solution of ammonia water and absolute ethanol with a mass ratio of 1:99. In steps (4) and (5), the acidic pH regulator is a mixed solution of glacial acetic acid and absolute ethanol with a mass ratio of 1:99.

[0046] Apply the obtained superhydrophilic nano - coating for photovoltaic glass to the surface of the photovoltaic glass by spraying, brushing, dipping and other techniques. After curing for 30 - 60 min, a superhydrophilic nano - coating can be formed. The contact angle of the photovoltaic glass after coating treatment is less than 5°, indicating that the surface of the photovoltaic glass has superhydrophilicity after coating treatment. When the photovoltaic glass has superhydrophilicity, it can not only reduce the accumulation of surface dirt and dust, keep the surface of the photovoltaic glass clean, but also, compared with the photovoltaic glass without coating, the light transmittance of the photovoltaic glass with coating is increased by 1% - 3%. Moreover, the photoelectric conversion efficiency of the photovoltaic string formed by the photovoltaic module after coating treatment is also increased by more than 5%. In addition, it also has good anti - ultraviolet and anti - aging properties, protecting the surface of the photovoltaic glass from damage by harsh weather and extending the service life of the photovoltaic module. Example 1

[0047] The preparation method of a super-hydrophilic nano-coating for photovoltaic glass is as follows: (1) Put 1 part by weight of tetraethyl orthosilicate, 5 parts by weight of deionized water and 6 parts by weight of isopropanol into a constant-temperature glass reactor at 35°C, and continuously stir at 300 - 400 rpm for 30 min; (2) Adjust the pH of the solution to 9.5 and continue stirring for 60 min; (3) Add 0.1 part by weight of propylene glycol block polyether and continue stirring for 30 min; (4) Adjust the pH of the solution to 7 and continue stirring for 120 min; (5) Add 10 parts by weight of absolute ethanol, 0.1 part by weight of wetting agent, and 0.2 part by weight of leveling agent respectively, adjust the pH of the solution to 2, and continue stirring for 60 min to obtain a super-hydrophilic nano-coating for photovoltaic glass. Example 2

[0048] The preparation method of a super-hydrophilic nano-coating for photovoltaic glass is as follows: (1) Put 2 parts by weight of tetraethyl orthosilicate, 9 parts by weight of deionized water and 11 parts by weight of isopropanol into a constant-temperature glass reactor at 35°C, and continuously stir at 300 - 400 rpm for 60 min; (2) Adjust the pH of the solution to 10 and continue stirring for 120 min; (3) Add 0.2 part by weight of propylene glycol block polyether and continue stirring for 60 min; (4) Adjust the pH of the solution to 7.5 and continue stirring for 180 min; (5) Add 15 parts by weight of absolute ethanol, 0.15 part by weight of wetting agent, and 0.4 part by weight of leveling agent respectively, adjust the pH of the solution to 4, and continue stirring for 90 min to obtain a super-hydrophilic nano-coating for photovoltaic glass. Example 3

[0049] The preparation method of a super-hydrophilic nano-coating for photovoltaic glass is as follows: (1) Put 1 part by weight of tetraethyl orthosilicate, 8 parts by weight of deionized water and 9 parts by weight of isopropanol into a constant-temperature glass reactor at 35°C, and continuously stir at 300 - 400 rpm for 45 min; (2) Adjust the pH of the solution to 9.7 and continue stirring for 90 min; (3) Add 0.1 part by weight of propylene glycol block polyether and continue stirring for 45 min; (4) Adjust the pH of the solution to 7.3 and continue stirring for 150 min; (5) Add 10 parts by weight of absolute ethanol, 0.1 part by weight of wetting agent, and 0.3 part by weight of leveling agent respectively, adjust the pH of the solution to 3, and continue stirring for 90 min to obtain a super-hydrophilic nano-coating for photovoltaic glass. Example 4

[0050] The preparation method of a super-hydrophilic nano-coating for photovoltaic glass is as follows: (1) Put 2 parts by weight of tetraethyl orthosilicate, 9 parts by weight of deionized water and 10 parts by weight of isopropanol into a constant-temperature glass reactor at 35 °C, and continuously stir at 300 - 400 rpm for 50 min; (2) Adjust the pH of the solution to 9.5 and continue stirring for 60 min; (3) Add 0.1 part by weight of propylene glycol block polyether and continue stirring for 45 min; (4) Adjust the pH of the solution to 7 and continue stirring for 150 min; (5) Add 15 parts by weight of absolute ethanol, 0.1 part by weight of wetting agent, and 0.4 part by weight of leveling agent respectively, adjust the pH of the solution to 2, and continue stirring for 90 min to obtain a super-hydrophilic nano-coating for photovoltaic glass.

[0051] Table 1 shows the comparison of the water contact angle and adhesion of photovoltaic glass before and after coating with a super-hydrophilic nano-coating for photovoltaic glass prepared in Examples 1 - 4 of coating implementation:

[0052]

[0053] It can be seen from Table 1 that the water contact angle of the coated photovoltaic glass decreases significantly, and all are less than 5°, and the surface adhesion reaches Grade 5B. There is no coating before coating, so the data is blank. For the specific illustration of the water contact angle, please refer to Figure 6 。

[0054] Table 2 shows the anti-static performance and anti-fouling and self-cleaning performance tests of photovoltaic glass after coating with a super-hydrophilic nano-coating for photovoltaic glass prepared in Examples 1 - 4 of coating implementation:

[0055]

[0056] From Figure 7 it can be seen that after the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Examples 1 - 4 of the present invention is repeatedly inserted into polyethylene foam, no polyethylene foam adheres to the surface, and it has good anti-static performance. However, a large amount of polyethylene foam adheres to the uncoated photovoltaic glass, indicating that the uncoated photovoltaic glass has poor anti-static performance.

[0057] Figure 8 In each of the three figures corresponding to each example, it shows the change process of the sludge being washed in the area coated with the super-hydrophilic nano-coating described in the corresponding example and the uncoated area. From Figure 8 it can be seen that after the photovoltaic glass coated with the super-hydrophilic nano-coating for photovoltaic glass described in Examples 1 - 4 of the present invention encounters water, the sludge can be washed clean, and it has good anti-fouling and self-cleaning performance. However, the sludge on the uncoated photovoltaic glass cannot be washed clean, and the anti-fouling and self-cleaning performance is poor.

[0058] Table 3 shows the actual application data of the present invention. A superhydrophilic nano-coating for photovoltaic glass prepared in Example 1 of the present invention was brush-coated on the surface of a photovoltaic string in a certain place. After actually working for one year in the natural environment, compared with the untreated photovoltaic string, the average annual total power generation increased by 6.12%.

[0059]

[0060] Figure 1 FIG. is the TEM image of a superhydrophilic nano-coating for photovoltaic glass described in Examples 1-3. From the images with different magnifications, it can be seen that the average particle size of the particles is 25-100 nm. And because the hydrolysis rate of tetraethyl orthosilicate in an alkaline environment is faster than that in an acidic environment, the corresponding polycondensation rate also increases, causing some of the silica particles to continuously collide and crosslink with each other and become larger, gradually aggregating from individual smaller nanoparticles into chain-like particles.

[0061] Figure 2 FIG. is the SEM image of a photovoltaic glass coated with a superhydrophilic nano-coating for photovoltaic glass described in Examples 1-3 of the present invention. The surface microscopic morphology of the inorganic coating with superhydrophilic self-cleaning, reduced reflection and increased light transmittance can be observed. The surface of the coating is relatively uniform, and the glass surface is basically covered by nanoparticles. The coating has a uniform nano-rough structure.

[0062] Figure 3 FIG. is the AFM image of a photovoltaic glass coated with a superhydrophilic nano-coating for photovoltaic glass described in Examples 1-3 of the present invention. The atomic force microscope was used to measure the surface roughness of the coating, which also shows that the surface of the coating has a certain roughness. Therefore, when SiO 2 is coated on the surface of the substrate, the silica particles will form a microcone nano-structure with a certain roughness on the surface of the substrate. The average roughness Ra are respectively: Example 1: 4.75 nm, Example 2: 5.63 nm, Example 3: 2.72 nm.

[0063] Figure 4 FIG. is the FT-IR spectrum of the superhydrophilic nano-coating formed after using the superhydrophilic nano-coating for photovoltaic glass described in Example 4 of the present invention. It can be seen that the absorption peaks at 794.12 cm -1 and 588.02 cm -1 correspond to the stretching vibration peak and bending vibration peak of Si-O respectively, proving that the main component of the coating is silica. There are two obvious absorption peaks at 1076.72 cm -1 and 454.50 cm -1 These two peaks correspond to the bending vibration peak and stretching vibration peak of Si-O-Si respectively, proving that there is a certain crosslinking effect between the silica particles. At 951.99 cm -1The peak at [specific position] is the bending vibration peak of Si-OH, which proves that the coating has a large number of hydrophilic groups, providing a basis for the preparation of superhydrophilic nano-coatings. In addition, there are stretching vibration peaks of -OH and bending vibration peaks of H-O-H at 3373.75 cm -1 and 1632.89 cm -1 , indicating that the prepared superhydrophilic coating has a large number of hydrophilic groups.

[0064] Figure 5 The test of the light transmittance of the photovoltaic glass coated with the superhydrophilic nano-coating for photovoltaic glass described in Example 4 of the present invention shows that, compared with the untreated photovoltaic glass, the photovoltaic glass treated with the superhydrophilic nano-coating for photovoltaic glass of the present invention has an average light transmittance in the range of 400 - 700 nm increased from 88.98% to 90.43%.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: still modifications or equivalent substitutions can be made to the specific embodiments of the present invention, and any modification or equivalent substitution without departing from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A super-hydrophilic nano coating for photovoltaic glass, characterized in that: The invention is prepared from the following chemical components in parts by weight: 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water, 6-11 parts by weight of isopropyl alcohol, 10-15 parts by weight of anhydrous ethanol, 0.1-0.2 parts by weight of propylene glycol block polyether, 0.1-0.15 parts by weight of a wetting agent, and 0.2-0.4 parts by weight of a leveling agent; The method for preparing the super-hydrophilic nano coating for photovoltaic glass is as follows: (1) 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water and 6-11 parts by weight of isopropanol are placed in a 35°C constant temperature glass reactor and stirred continuously at a speed of 300-400 rpm for 30-60 min; (2) Add an alkaline pH regulator until the pH of the solution is adjusted to between 9.5 and 10, and continue stirring for 60 to 120 minutes; (3) Add 0.1-0.2 parts by weight of propylene glycol block polyether and continue stirring for 30-60 minutes; (4) Add an acidic pH regulator until the pH of the solution is adjusted to between 7 and 7.5, and continue stirring for 120 to 180 minutes; (5) adding 10-15 parts by weight of anhydrous ethanol, 0.1-0.15 parts by weight of a wetting agent, and 0.2-0.4 parts by weight of a leveling agent, respectively, and then adding an acidic pH regulator until the pH of the solution is adjusted to between 2 and 4, and continuing to stir for 60-90 minutes to obtain the super-hydrophilic nano-coating for photovoltaic glass; The suspended matter produced in the super-hydrophilic nano coating for photovoltaic glass is mainly chain-like silicon dioxide nanoparticles.

2. The super-hydrophilic nano coating for photovoltaic glass according to claim 1, characterized in that: The average particle size of the chain-like silica nanoparticles is 25-100 nm.

3. The super-hydrophilic nano coating for photovoltaic glass according to claim 1, characterized in that: The wetting agent is one or more nonionic surfactants selected from alkylphenol polyoxyethylene ether, high-carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene amine, polyoxyethylene amide, fatty acid ethylene glycol ester, monoglyceride, sorbitan fatty acid ester, polyoxyethylene-polyoxypropylene copolymer, and fatty acid alkanolamide.

4. The super-hydrophilic nano coating for photovoltaic glass according to claim 1, characterized in that: The leveling agent is one or more organic silicon leveling agents selected from the group consisting of polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, and polydimethylsiloxane modified with reactive functional groups.

5. The method for preparing a super-hydrophilic nano-coating for photovoltaic glass according to any one of claims 1 to 4, characterized in that: The process is as follows: (1) 1-2 parts by weight of tetraethyl orthosilicate, 5-9 parts by weight of deionized water and 6-11 parts by weight of isopropanol are placed in a 35°C constant temperature glass reactor and stirred continuously at a speed of 300-400 rpm for 30-60 min; (2) Add an alkaline pH regulator until the pH of the solution is adjusted to between 9.5 and 10, and continue stirring for 60 to 120 minutes; (3) Add 0.1-0.2 parts by weight of propylene glycol block polyether and continue stirring for 30-60 minutes; (4) Add an acidic pH regulator until the pH of the solution is adjusted to between 7 and 7.5, and continue stirring for 120 to 180 minutes; (5) Add 10-15 parts by weight of anhydrous ethanol, 0.1-0.15 parts by weight of a wetting agent, and 0.2-0.4 parts by weight of a leveling agent, respectively, and then add an acidic pH regulator until the pH of the solution is adjusted to between 2 and 4, and continue stirring for 60-90 minutes to obtain the super hydrophilic nano coating for photovoltaic glass.

6. The method for preparing a super-hydrophilic nano coating for photovoltaic glass according to claim 5, characterized in that: The alkaline pH regulator is a mixed solution of ammonia water and anhydrous ethanol in a mass ratio of 1:

99.

7. The method for preparing a super-hydrophilic nano coating for photovoltaic glass according to claim 5, characterized in that: The acidic pH regulator is a mixed solution of glacial acetic acid and anhydrous ethanol in a mass ratio of 1:

99.

8. An application of a super-hydrophilic nano coating for photovoltaic glass, characterized in that: The application method is: apply the super-hydrophilic nano-coating for photovoltaic glass described in any one of claims 1 to 4 to the front of the photovoltaic glass, and after curing at room temperature for 30-60 minutes, a super-hydrophilic nano-coating can be formed on the front of the photovoltaic glass. The thickness of the super-hydrophilic nano-coating formed by curing is 150-250nm.

9. The use of a super-hydrophilic nano coating for photovoltaic glass according to claim 8, characterized in that: The water contact angle of the photovoltaic glass after coating treatment is less than 5°.

10. The use of a super-hydrophilic nano coating for photovoltaic glass according to claim 8, characterized in that: The light transmittance of the coated photovoltaic glass is increased by 1-3% compared with the uncoated photovoltaic glass.

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