Preparation method of special high-transmittance super-hydrophobic spray for surface of photovoltaic module

Abstract

The invention discloses a preparation method of special high-transmittance super-hydrophobic spray for the surface of a photovoltaic module, and belongs to the technical field of preparation of super-hydrophobic materials for the surface of the photovoltaic module. Commercial nano hydrophobic silicon dioxide is used as a raw material, is subjected to water dispersion treatment, is mixed with edible oil, and is stirred at a high speed for 10 minutes to form a uniform and stable Pickering emulsion. The emulsion is sprayed or coated on the surface of a photovoltaic panel, and the transparent super-hydrophobic coating can be obtained after high-temperature airing or hot air drying. According to the preparation method disclosed by the invention, the used raw material SiO2 is high in light transmittance, and solid particles can be uniformly dispersed on the surface of the photovoltaic substrate after the Pickering emulsion is prepared. Edible oil and water are removed after high-temperature airing or hot air drying, uniform dispersion of SiO2 is achieved, and the formed photovoltaic module surface coating has the characteristics of high light transmittance and super-hydrophobicity.

Description

Technical Field

[0001] The invention belongs to the technical field of super-hydrophobic materials for photovoltaic module surfaces, and in particular relates to a method for preparing a highly light-transmitting super-hydrophobic spray specially used for photovoltaic module surfaces. Background Art

[0002] Photovoltaic modules, also known as solar cell modules, are composed of high-efficiency crystalline silicon solar cells, ultra-white cloth-textured tempered glass, EVA, transparent TPT backplane and aluminum alloy frame. It has the characteristics of long service life and strong mechanical pressure resistance. It is mainly sealed by glue and lamination to prevent the adverse effects of external environment such as humid weather and acid rain on the photoelectric conversion efficiency of the battery. In order to protect photovoltaic modules, the upper cover is generally used to cover the photovoltaic cell module to reduce the subsequent maintenance cost caused by environmental factors to the battery. As the outermost layer of the battery module, the upper cover must have high light transmittance and be strong. At present, the main materials of the upper cover are: tempered glass, polyacrylic resin, fluorinated ethylene propylene, transparent polyester, polycarbonate, etc., with low-iron tempered glass being the most commonly used. However, after the upper cover is installed, the surface of the upper cover is very easy to be contaminated with dirt during the wind and rain in the outdoor use environment, which greatly affects the photoelectric conversion efficiency of the battery. At the same time, photovoltaic modules are installed on the roof, and there is no objective condition for frequent wiping. Therefore, whether it is possible to develop a surface super-hydrophobic coating and simply apply it on the surface of the upper cover to keep its surface clean is a new idea to reduce the maintenance cost of photovoltaic modules, ensure maintenance safety, and improve the overall conversion efficiency.

[0003] Nano-silica is a mature nano-scale material that has been commercially developed. Hydrophobic / hydrophilic functional particles can be obtained through surface modification. Pickering emulsion uses ultrafine nanoparticles as emulsifiers to stabilize the emulsions uniformly at the oil-water interface. It is widely used in the fields of food, cosmetics, and health products. However, there are no reports on the preparation of Pickering emulsions using nano-silica as an emulsifier and their application in the light-transmitting coating of photovoltaic modules.

[0004] Therefore, based on the above background, how to use nano-silica with high light transmittance as raw material to form Pickering emulsion and apply it to photovoltaic modules to give the photovoltaic modules surface super-hydrophobic and high light transmittance, while also effectively improving the conversion efficiency of photovoltaic modules and reducing maintenance costs, has become a problem that needs to be solved urgently. Summary of the invention

[0005] The first purpose of the present invention is to propose a highly transparent super-hydrophobic spray specially for the surface of photovoltaic modules. The spray can be sprayed directly on the photovoltaic panels, and then dried at high temperature or with hot air to remove the oil and water on the surface of the photovoltaic panels, leaving a uniform silica nanoparticle coating on the surface.

[0006] The second purpose of the present invention is to propose a method for preparing a high-transmittance super-hydrophobic spray specially for the surface of photovoltaic modules. Through simple dispersion and ultrasonic treatment, nanoparticles are used as emulsifiers to form a uniformly dispersed Pickering emulsion at the oil-water interface. High-transmittance super-hydrophobic spray can be obtained by only high-speed stirring, which greatly simplifies the preparation steps and improves the preparation efficiency.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a highly transparent super-hydrophobic spray specially for the surface of a photovoltaic module comprises taking hydrophobic nano-silicon dioxide as a raw material, dispersing it in water by ultrasonication, mixing it with edible oil and stirring it at high speed to form a Pickering emulsion, namely, a highly transparent super-hydrophobic spray specially for the surface of a photovoltaic module.

[0009] Furthermore, the average particle size of the hydrophobic nano-silica is 10 to 50 nm.

[0010] Furthermore, in the dispersion, the mass ratio of hydrophobic nano-silicon dioxide to water is 0.5-2%.

[0011] Furthermore, the volume ratio of edible oil to water is 1:19 to 1:9.

[0012] Furthermore, the ultrasonic treatment time is 5 to 10 minutes.

[0013] Furthermore, the edible oil is selected from sunflower oil and corn oil.

[0014] Furthermore, the high-speed stirring rate is 9000-12000 r / min; and the stirring time is 5-10 min.

[0015] Furthermore, a highly transparent super-hydrophobic spray specially prepared for the surface of photovoltaic modules is obtained.

[0016] Furthermore, the highly transparent super-hydrophobic spray specially used for the surface of photovoltaic modules is applied on the surface of photovoltaic modules.

[0017] Furthermore, the prepared Pickering emulsion is directly sprayed or coated onto the surface of the photovoltaic panel, and then dried in the sun at high temperature or with hot air.

[0018] Existing commercial nano hydrophobic silica particles have high light transmittance and can be used as a key material for surface hydrophobic modification. In the preparation process of super hydrophobic materials, how to achieve uniform dispersion of nano materials and orderly construction of surface structure is the key to determining the final hydrophobic performance. The present invention uses nano hydrophobic silica particles as an emulsifier for Pickering emulsions, and achieves uniform dispersion of transparent silica particles by adjusting the oil-water ratio and morphology. After coating or spraying the cover plate on the photovoltaic module, the photovoltaic module surface can be super hydrophobic and have high light transmittance by hot air or high temperature drying, thereby improving the conversion efficiency of photovoltaic modules, reducing the later maintenance cost of modules, and ensuring the maintenance safety of rooftop photovoltaic modules.

[0019] Compared with the prior art, the advantages of the present invention are as follows:

[0020] 1) The highly light-transmitting super-hydrophobic spray specially used for the surface of photovoltaic modules of the present invention has high light transmittance and hydrophobicity when sprayed on photovoltaic panels.

[0021] 2) The present invention realizes the dispersion of nano-silicon dioxide by forming a Pickering emulsion, which is a cross-fusion of the emulsion system and the photovoltaic system.

[0022] 3) The spray of the present invention can be directly sprayed on the photovoltaic panel, dried naturally or with hot air, to remove the oil and water on the surface of the photovoltaic panel, leaving only a uniform silica nanoparticle coating, and the actual application operation is simple.

[0023] 4) The present invention uses nanoparticles, does not require the use of external chemical reagents, is low-cost, and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a physical picture of the Pickering emulsion prepared in Example 1-5 after being left for 3 days; wherein, from left to right are the products prepared in Example 1-5;

[0025] Figure 2 This is a real picture of the Pickering emulsion prepared in Comparative Example 1 and Comparative Example 2 after being placed for 3 days; in the figure, from left to right are the products prepared in Comparative Example 1 and Comparative Example 2;

[0026] Figure 3 This is a result diagram of the contact angle of the Pickering emulsion surface constructed with silicon dioxide nanoparticles; in the figure, from top to bottom are the contact angle diagrams of Examples 1-5, and from left to right are the contact angle result diagrams of Examples 0s, 30s and 60s.

[0027] Figure 4 The light transmittance diagrams of photovoltaic panels not coated with the emulsion of the present invention and coated with the emulsion of the present invention are shown in FIG. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with specific embodiments.

[0029] The nano-silica used in the following examples are all commercially available gas-phase hydrophobic nano-silica with a particle size of 10-50 nm.

[0030] Example 1

[0031] A method for preparing a highly transparent super-hydrophobic spray for a photovoltaic module surface, comprising the following steps:

[0032] First, disperse nano-silica in 50 mL of water with a mass ratio of nano-silica to water of 0.5%, treat with ultrasound (power of 150 W) for 5 min, then add sunflower oil with a volume ratio of 5% of the total amount, stir at high speed for 10 min at a speed of 9000 r / min to obtain a Pickering emulsion.

[0033] Example 2

[0034] A method for preparing a highly transparent super-hydrophobic spray for a photovoltaic module surface, comprising the following steps:

[0035] First, disperse nano-silica in 50 mL of water with a mass ratio of nano-silica to water of 1%, and treat with ultrasound (power of 150 W) for 10 min; then add sunflower oil with a volume ratio of 8% of the total amount, stir at high speed for 10 min at a speed of 9000 r / min to obtain a Pickering emulsion.

[0036] Example 3

[0037] A method for preparing a highly transparent super-hydrophobic spray for a photovoltaic module surface, comprising the following steps:

[0038] First, disperse nano-silica in 50 mL of water with a mass ratio of nano-silica to water of 1.5%, treat with ultrasound (power of 150 W) for 5 min, then add sunflower oil with a volume ratio of 10% of the total amount, stir at high speed for 10 min at a speed of 12000 r / min to obtain a Pickering emulsion.

[0039] Example 4

[0040] A method for preparing a highly transparent super-hydrophobic spray for a photovoltaic module surface, comprising the following steps:

[0041] First, disperse nano-silica in 50 mL of water with a mass ratio of nano-silica to water of 2%, treat with ultrasound (power of 150 W) for 10 min, then add sunflower oil with a volume ratio of 10% of the total amount, stir at high speed for 10 min at a speed of 10000 r / min to obtain a Pickering emulsion.

[0042] Example 5

[0043] A method for preparing a highly transparent super-hydrophobic spray for a photovoltaic module surface, comprising the following steps:

[0044] First, disperse nano-silicon dioxide (particle size of 10-50nm) in 50mL of water, with a mass ratio of nano-silicon dioxide to water of 1.5%, treat with ultrasound (power of 150W) for 10min, then add sunflower oil with a volume ratio of 10% of the total amount, stir at high speed for 10min at a speed of 12000r / min, and obtain a Pickering emulsion. Figure 1 shown.

[0045] Comparative Example 1

[0046] The preparation of nano silicon dioxide spray is the same as that in Example 1, except that no sunflower oil is added, and water is used instead of sunflower oil to obtain the product.

[0047] Comparative Example 2

[0048] The preparation of nano-silicon dioxide spray is the same as in Example 1, except that Tween 80 is used instead of sunflower oil to obtain an emulsion. Figure 2 shown.

[0049] Example 6

[0050] Product performance testing

[0051] 1. Stability test

[0052] The Pickering emulsions obtained in Examples 1-5 and the products obtained in Comparative Examples 1 and 2 were left to stand at room temperature for 3 days. Figure 1 As shown, the Pickering emulsions prepared in Examples 1-5 of the present application have good dispersion and emulsification, good stability, and are homogeneous, which can meet the use requirements. The product of Comparative Example 1 is a suspension, which immediately delaminates after the stirring stops, and cannot be used for coating. The product prepared in Comparative Example 2, although an emulsion, also delaminates after standing for 3 days, and is unevenly dispersed, and cannot be used for coating.

[0053] 2. Water contact angle test

[0054] The Pickering emulsions prepared in Examples 1-5 were directly sprayed onto the surface of a glass plate and dried with hot air at 80°C. The contact angle was measured using a contact angle meter equipped with a high-speed camera. Figure 3 2 μL of ultrapure water was dropped on a dried glass slide by a microsyringe, and the contact angle data at 0s, 30s and 60s were quickly photographed and recorded. The results are shown in Table 1.

[0055] 3. Transmission test

[0056] The Pickering emulsion prepared in Example 1 was directly sprayed on the surface of the glass plate and dried with hot air at 80°C. The glass plate without spraying was used as a control, and the transmittance of the glass plate was tested by ultraviolet spectrophotometer with a wavelength range of 300-800nm ​​and a scanning interval of 2nm. The results are as follows: Figure 4 As shown, the glass after spraying has a similar transmittance as the control, indicating that the Pickering emulsion coating of the present application has a very good transmittance.

[0057] Table 1: Water contact angle test results of the products of Examples 1-5

[0058] Example 1 Example 2 Example 3 Example 4 Example 5 Water contact angle (°) 96 99 103 123 117

[0059] The results in Table 1 show that the coatings prepared by the present invention have good hydrophobicity and can be applied to photovoltaic modules.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces, characterized in that: Hydrophobic nano-silica is used as the raw material, dispersed in water by ultrasound, mixed with edible oil and stirred at high speed to form a Pickering emulsion, which is a highly transparent super-hydrophobic spray specially used on the surface of photovoltaic modules.

2. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: The average particle size of the hydrophobic nano-silicon dioxide is 10 to 50 nm.

3. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: In the dispersion, the mass ratio of hydrophobic nano-silicon dioxide to water is 0.5-2%.

4. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: The volume ratio of edible oil to water is 1:19 to 1:

9.

5. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: The ultrasonic treatment time is 5 to 10 minutes.

6. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: The edible oil is selected from sunflower oil and corn oil.

7. The method for preparing a highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 1, characterized in that: The high-speed stirring rate is 9000-12000 r / min; the stirring time is 5-10 min.

8. A highly transparent super hydrophobic spray for photovoltaic module surface prepared by the method according to any one of claims 1 to 7.

9. Use of the highly transparent super-hydrophobic spray for photovoltaic module surfaces according to claim 8 in preparing photovoltaic module surface coatings.

10. The use according to claim 9, characterized in that: The prepared Pickering emulsion is directly sprayed or coated onto the surface of the photovoltaic panel, and then dried under high temperature or with hot air.

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