Self-cleaning nano coating suitable for photovoltaic modules, preparation method and application

Abstract

The invention discloses a self-cleaning nano coating suitable for photovoltaic modules, a preparation method and an application thereof. Organic silicate and nano silicon dioxide are added to a hydrochloric acid solution for hydrolysis, and then a magnesium fluoride acid hydrolyzate is added to perform dihydrolysis to obtain a mixed sol material of nano silicon dioxide and magnesium fluoride; a mixed alcohol solution and a nano titanium dioxide sol are added to the mixed sol material to obtain a nano silicon-titanium compound complex magnesium fluoride sol, i.e., a composite sol material; a substrate is sequentially placed in acetone and deionized water for ultrasonic cleaning, and then dried; the nano silicon-titanium compound complex magnesium fluoride sol obtained in step 2 is taken, coated on a substrate, and then allowed to stand and dry to obtain a self-cleaning nano coating.

Description

Technical Field

[0001] The present invention relates to the technical field of self-cleaning materials, and in particular to a self-cleaning nano coating suitable for photovoltaic modules, a preparation method and an application thereof. Background Art

[0002] With economic development, the construction and operation of solar photovoltaic power stations in various countries have also entered a peak. At the same time, the reduction in power generation efficiency of solar photovoltaic panels due to surface pollution has also become a problem that needs to be solved urgently. Natural pollution of solar photovoltaic panels is difficult to avoid. In order to maintain the power generation efficiency of photovoltaic panels, regular manual cleaning is required, which incurs huge cleaning costs. Moreover, most solar photovoltaic power station bases are built in suburban areas, and photovoltaic panels are covered with sand and dust, which greatly reduces the power generation efficiency. To keep the surface of photovoltaic panels clean, manual cleaning in these environments is very difficult and expensive. The existing methods of conventional manual cleaning, robot cleaning, high-pressure water cleaning, etc. will cause rapid damage to the surface light-enhancing coating of solar photovoltaic panels, resulting in accelerated attenuation of light transmittance. Therefore, preparing dust-proof and self-cleaning coatings on the surface of photovoltaic panels has become the preferred way to prevent pollution of solar photovoltaic panels.

[0003] However, the coating in the prior art has problems such as single anti-reflection film performance, insufficient coating adhesion and easy contamination.

[0004] Therefore, a self-cleaning nano coating with excellent anti-reflection and anti-transmission properties and super-hydrophilic properties suitable for photovoltaic modules, a preparation method and an application are now provided. Summary of the invention

[0005] In order to solve the above problems in the prior art, the present application provides a self-cleaning nano coating with excellent anti-reflection and anti-transmission properties, super hydrophilic properties and suitable for photovoltaic modules, a preparation method and application.

[0006] First, the present invention provides a method for preparing a self-cleaning nano coating suitable for a photovoltaic module, the steps of which are as follows:

[0007] Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, reacting for 2-5 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:1-3:0.05-0.15, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 0.1%-1%;

[0008] Step 2: adding the mixed alcohol solution and the nano titanium dioxide sol to the mixed sol material to obtain the nano silicon titanium compound complex magnesium fluoride sol, i.e. the composite sol material; wherein the three are mixed in a ratio range of 1: 2-5: 0.1-0.5;

[0009] Step 3: placing the substrate in acetone and deionized water for ultrasonic cleaning in turn, and drying; taking the nano-silicon titanium compound complex magnesium fluoride sol prepared in step 2, coating it on the substrate and letting it stand to dry, so as to obtain a self-cleaning nano coating.

[0010] The particle size of nanosilica ranges from 10-50 nm.

[0011] The mixed alcohol solution includes a mixture of any one or more of ethanol, methanol, isopropanol, propylene glycol methyl ether, and n-propanol, and a dispersant; wherein the dispersant accounts for 0.1%-0.5%.

[0012] In step 3, the power of ultrasonic cleaning is 300 W and the time is 5 min-10 min.

[0013] In step 3, the standing time is 3-10 h.

[0014] In step 3, the coating includes doctor blade coating, sponge coating, solution dipping coating, gravity flow coating or pressure spray coating.

[0015] Secondly, the present invention also provides a self-cleaning nano coating suitable for photovoltaic modules, and the self-cleaning nano coating is prepared by the preparation method as described above.

[0016] The thickness of the self-cleaning nano coating ranges from 160 to 175 nm.

[0017] Thirdly, the present invention also provides a self-cleaning nano coating suitable for photovoltaic modules prepared by the preparation method as described above and used in the fields of dustproof, self-cleaning, anti-reflection or anti-radiation coating.

[0018] The technical solution of the present invention has the following advantages:

[0019] In the present invention, a composite sol material formed by nano silicon dioxide, magnesium fluoride and nano titanium dioxide under acidic conditions introduces rich functional groups on the substrate, wherein the breaking and polymerization cross-linking of the organic silicate silicon oxygen bond enables the coating to be firmly attached to the surface of the substrate and have excellent electrical conductivity, and the low refractive index of the nano silicon dioxide and magnesium fluoride materials endows the coating with excellent anti-reflection and anti-reflection performance; the present invention utilizes the synergistic reaction of the rich hydroxyl functional groups on the surface of the coating and the holes, high-energy electrons and strong oxidizing free radicals generated by the light excitation of the nano titanium dioxide to construct a composite super-hydrophilic-photocatalytic self-cleaning anti-fouling coating on the surface of the substrate, which is particularly suitable for photovoltaic modules; the present invention overcomes the shortcomings of the traditional anti-reflection film, such as the single performance, insufficient adhesion of the coating and easy pollution, and gives full play to the advantages of the nano silicon titanium compound complex magnesium fluoride composite material, such as low refractive index, super-hydrophilicity, photocatalysis, excellent electrical conductivity, etc. The composite coating is simple to prepare, the single-layer structure is easy to assemble, and the room temperature curing is convenient for outdoor distributed photovoltaic power station application, and the anti-reflection and anti-reflection and self-cleaning performances are efficiently combined, the service life of the coating is improved, and the cleaning and maintenance costs are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A comparative schematic diagram of Comparative Example 1;

[0022] Figure 2 A comparative schematic diagram of Comparative Example 2;

[0023] Figure 3 A comparative schematic diagram of Comparative Example 3;

[0024] Figure 4 A comparative schematic diagram of Comparative Example 4;

[0025] Figure 5 (a) The appearance of the self-cleaning nanocoating at different stages of the photocatalytic experiment, from left to right, the appearance of the coating at 0, 8, and 16 h of photocatalysis; (b) The absorbance curve of the glass coated with the self-cleaning nanocoating in the range of 600-700 nm before and after photocatalysis; (c) The change of the mean absorbance of the sample in the range of 600-700 nm at different stages of the photocatalytic experiment;

[0026] Figure 6 (a) and (b) are scanning electron microscope images of the coating cross section at different magnifications; (c) and (d) are scanning electron microscope images of the coating surface at different magnifications. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. The following content is only an example and explanation of the concept of the present invention. The technicians in the relevant technical field make various modifications or supplements to the specific implementation cases described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all belong to the protection scope of the present invention. The experimental reagents and materials used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0028] First, the present invention provides a method for preparing a self-cleaning nano coating suitable for a photovoltaic module, the steps of which are as follows:

[0029] Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, reacting for 2-5 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:1-3:0.05-0.15, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 0.1%-1%;

[0030] Step 2: adding the mixed alcohol solution and the nano titanium dioxide sol to the mixed sol material to obtain the nano silicon titanium compound complex magnesium fluoride sol, i.e. the composite sol material; wherein the three are mixed in a ratio range of 1: 2-5: 0.1-0.5;

[0031] Step 3: placing the substrate in acetone and deionized water for ultrasonic cleaning in turn, and drying; taking the nano-silicon titanium compound complex magnesium fluoride sol prepared in step 2, coating it on the substrate and letting it stand to dry, so as to obtain a self-cleaning nano coating.

[0032] The particle size of nanosilica ranges from 10-50 nm.

[0033] The mixed alcohol solution includes a mixture of any one or more of ethanol, methanol, isopropanol, propylene glycol methyl ether, and n-propanol, and a dispersant; wherein the dispersant accounts for 0.1%-0.5%.

[0034] In step 3, the ultrasonic cleaning power is 300 W and the time is 5 min-10 min.

[0035] In step 3, the standing time is 3-10 h.

[0036] In step 3, the coating includes doctor blade coating, sponge coating, solution dipping coating, gravity flow coating or pressure spray coating.

[0037] like Figure 6 As shown, (a) is the scanning electron microscope image of the coating cross section at 10.00kx, and (b) is the scanning electron microscope image of the coating cross section at 50.00kx. It is observed that the thickness of the single-layer coating is within 160-175 nm; (c) is the scanning electron microscope image of the coating surface at 10.00kx, and (d) is the scanning electron microscope image of the coating surface at 100.00kx. It is observed that the regional morphology of the coating is a uniform pore structure.

[0038] Secondly, the present invention also provides a self-cleaning nano coating suitable for photovoltaic modules, and the self-cleaning nano coating is prepared by the preparation method as described above.

[0039] The thickness of the self-cleaning nanocoating ranges from 160-175 nm and is generally a single layer.

[0040] Thirdly, the present invention also provides a self-cleaning nano coating suitable for photovoltaic modules prepared by the preparation method as described above and used in the fields of dustproof, self-cleaning, anti-reflection or anti-radiation coating.

[0041] The composite sol material formed by nano-silicon dioxide, magnesium fluoride and nano-titanium dioxide under acidic conditions introduces abundant functional groups on the substrate, wherein the breaking and polymerization cross-linking of the organic silicate silicon oxygen bond enables the coating to be firmly attached to the surface of the substrate and has excellent electrical conductivity, and the low refractive index of the nano-silicon dioxide and magnesium fluoride materials endows the coating with excellent anti-reflection and anti-reflection performance; the present invention utilizes the synergistic reaction of abundant hydroxyl functional groups on the coating surface and holes, high-energy electrons and strong oxidizing free radicals generated by light excitation of nano-titanium dioxide to construct a composite super-hydrophilic-photocatalytic self-cleaning anti-fouling coating on the surface of the substrate, which is particularly suitable for photovoltaic modules; the present invention overcomes the shortcomings of the traditional anti-reflection film with single performance, insufficient coating adhesion and easy pollution, and gives full play to the advantages of low refractive index, super-hydrophilicity, photocatalysis, excellent electrical conductivity and the like of the nano-silicon-titanium compound complex magnesium fluoride composite material; the composite coating is simple to prepare, the single-layer structure is easy to assemble, and the room temperature curing is convenient for outdoor distributed photovoltaic power station application, and the anti-reflection and anti-reflection and self-cleaning performances are efficiently combined, the service life of the coating is improved, and the cleaning and maintenance costs are reduced. Example 1

[0042] The preparation method of the present application is used to prepare a self-cleaning nano coating suitable for photovoltaic modules, and the specific steps are as follows:

[0043] Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, and after reacting for 4 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:2:0.1, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 0.2%;

[0044] Step 2: Adding a mixed alcohol solution and a nano-titanium dioxide sol to the mixed sol material to obtain a nano-silicon-titanium compound complexed magnesium fluoride sol, ie, a composite sol material; wherein the three are mixed in a ratio range of 1:3:0.2;

[0045] Step 3: Place the 10 cm*10 cm photovoltaic glass substrate in acetone and deionized water for ultrasonic cleaning.

[0046] The ultrasonic power is 300 W, the ultrasonic treatment time is 10 min, and then dried; the nano-silicon-titanium compound complexed magnesium fluoride sol prepared in step 2 is taken, coated on the substrate, and then allowed to stand and dry for 8 hours to obtain a self-cleaning nano coating. Example 2

[0047] The preparation method of the present application is used to prepare a self-cleaning nano coating suitable for photovoltaic modules, and the specific steps are as follows:

[0048] Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, and after reacting for 2 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:2:0.05, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 0.1%;

[0049] Step 2: Adding a mixed alcohol solution and a nano-titanium dioxide sol to the mixed sol material to obtain a nano-silicon-titanium compound complexed magnesium fluoride sol, ie, a composite sol material; wherein the three are mixed in a ratio range of 1:2:0.1;

[0050] Step 3: Place a 10 cm*10 cm photovoltaic glass substrate in acetone and deionized water for ultrasonic cleaning in turn, with an ultrasonic power of 300 W and an ultrasonic treatment time of 5 min, and then dry; take the nano-silicon-titanium compound complex magnesium fluoride sol prepared in step 2, apply a coating on the substrate, and let it stand and dry for 4 hours to obtain a self-cleaning nano coating. Example 3

[0051] The preparation method of the present application is used to prepare a self-cleaning nano coating suitable for photovoltaic modules, and the specific steps are as follows:

[0052] Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, and after reacting for 5 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:3:0.15, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 1%;

[0053] Step 2: Adding a mixed alcohol solution and a nano-titanium dioxide sol to the mixed sol material to obtain a nano-silicon-titanium compound complexed magnesium fluoride sol, ie, a composite sol material; wherein the three are mixed in a ratio range of 1:5:0.5;

[0054] Step 3: Place a 10 cm*10 cm photovoltaic glass substrate in acetone and deionized water for ultrasonic cleaning in turn, with an ultrasonic power of 300 W and an ultrasonic treatment time of 10 min, and then dry; take the nano-silicon-titanium compound complex magnesium fluoride sol prepared in step 2, apply a coating on the substrate, and let it stand and dry for 10 hours to obtain a self-cleaning nano coating.

[0055] Control group 1

[0056] The same 10 cm*10 cm photovoltaic glass was taken and cleaned and dried in the same manner as in Example 1, that is, ultrasonically cleaned in acetone and deionized water and dried, as Control Group 1.

[0057] Control group 2

[0058] The same 10 cm*10 cm photovoltaic glass was taken and cleaned and dried in the same manner as in Example 1, that is, ultrasonically cleaned and dried in acetone and deionized water, and then coated with a purchased common nano-silica hydrophilic coating as control group 2. Comparative Example 1

[0059] The water contact angle of the photovoltaic glass surface coated with the self-cleaning nano coating prepared in Example 1 was measured using a contact angle meter. Figure 1 (a), its water contact angle is 2-5°, proving that it has super hydrophilicity; the water contact angle of the photovoltaic glass surface of the control group 1 is measured by a contact angle meter, as shown in Figure 1 (b), its water contact angle is 40-50°, and it does not have super hydrophilicity; this comparison proves that the self-cleaning nano coating prepared in Example 1 has excellent super hydrophilicity. Comparative Example 2

[0060] The transmittance data curves of the photovoltaic glass coated with the self-cleaning nano-coating prepared in Example 1 and the photovoltaic glass of the control group 1 were measured by using an ultraviolet spectrophotometer with an integrating sphere, with the scanning wavelength set to 400-1100 nm and the scanning interval set to 5 nm. Figure 2 ; By comparison, it can be seen that the transmittance of the photovoltaic glass in Example 1 increased by 3-4% on average compared with that in the control group 1, proving that the self-cleaning nano-coating prepared in Example 1 can effectively improve the transmittance of the photovoltaic glass. Comparative Example 3

[0061] In the xenon lamp weather resistance test chamber, set the blackboard temperature to 65°C, the temperature to 35°C, the humidity to 40%, and the irradiation intensity to 50W / m 2 , after running continuously for 1.8 hours, spray the sample with water and continue running for 0.2 hours as a cycle; take it out after 5 cycles, use an ultraviolet spectrophotometer with an integrating sphere, set the scanning wavelength to 400-1100 nm, and the scanning interval to 5 nm to measure the transmittance data of the coating at different aging times;

[0062] like Figure 3 As shown, compared with the control group 2, it can be seen that the self-cleaning nano coating prepared in Example 1 has excellent anti-reflection and anti-aging performance. Under harsh experimental conditions, the time for maintaining a high level of anti-reflection ability is much longer than that of the coating in the control group 2. Therefore, when the self-cleaning nano coating prepared in Example 1 is used as a photovoltaic anti-reflection coating in outdoor applications, it can maintain the anti-reflection ability for a long time, which helps to improve the power generation efficiency of photovoltaic modules. Comparative Example 4

[0063] The surface resistance of the paint film was measured using a 1155TMF multifunctional insulation resistance tester. Under the same conditions, the surface resistance test was performed on the photovoltaic glass coated with the self-cleaning nano coating prepared in Example 1 and the photovoltaic glass of the control group 1. The surface resistance data were recorded as shown in Table 1:

[0064]

[0065] It is generally believed that the surface resistance is 10 6 -10 8 The conductivity is good in the range of 10Ω, and it has excellent antistatic performance. It is not easy to absorb tiny dust and can keep the surface of the substrate clean. 7 -10 8 Ω range, with good antistatic performance. The photovoltaic glass surface resistance of control group 1 is larger (10 10 Ω), does not have antistatic properties.

[0066] In order to intuitively demonstrate the excellent properties of the present invention in terms of antistatic properties and resistance to adsorbing tiny dust, fine dust with a particle size of less than 50 μm was gently sprayed on the surface of the photovoltaic glass coated with the self-cleaning nano coating prepared in Example 1, and the dust adhesion was observed. Figure 4 As shown on the right, dust hardly adheres, proving that the antistatic performance is good; under the same test conditions, the surface of the photovoltaic glass of the control group 1 is as follows Figure 4 As shown on the left, dust adhesion is obvious, proving that it does not have antistatic properties.

[0067] Further, the self-cleaning nano coating prepared in Example 1 was tested, specifically:

[0068] 35 mL of 0.02 mM methylene blue solution was poured into the experimental reaction tank, and the glass coated with the self-cleaning nano-coating prepared in Example 1 was placed in the reaction tank to adsorb the dye in the dark for 12 hours. After the adsorption was completed, the glass adsorbed with the dye was placed in a xenon lamp weather resistance test box, and the blackboard temperature was set to 65°C, the temperature was 25°C, the humidity was 40%, and the irradiation intensity was 500W / m 2 , running continuously for 2 h as one cycle, and a total of 8 cycles were performed. After each cycle, the glass was taken out and the absorbance value of the glass was measured using a UV spectrophotometer with an integrating sphere. The scanning wavelength was set to 600-700 nm and the scanning interval was 5 nm. The results are shown in Figure 5 shown.

[0069] Depend on Figure 5 (a) It can be seen that the self-cleaning nano-coating prepared in Example 1 has an excellent effect on removing surface organic matter; Figure 5 (b) shows that before and after the photocatalytic experiment, the absorbance of the glass coated with the self-cleaning nano-coating prepared in Example 1 in the range of 600-700 nm has a very obvious decrease. Figure 5 (c) The change in the average absorbance of the glass at different stages of the photocatalytic experiment shows that the self-cleaning nano-coating prepared in Example 1 has a high removal rate of methylene blue and a very strong photocatalytic activity.

[0070] In summary, the self-cleaning nano-coating suitable for photovoltaic modules provided in the present application has the advantages of low refractive index, super hydrophilicity, photocatalysis, excellent electrical conductivity, etc.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a self-cleaning nano coating suitable for photovoltaic modules, characterized in that: Here are the steps: Step 1: adding organic silicate and nano-silicon dioxide to hydrochloric acid solution for hydrolysis, reacting for 2-5 hours, adding magnesium fluoride acid hydrolysis solution, dihydrolyzing to obtain a mixed sol material of nano-silicon dioxide and magnesium fluoride; wherein the mass ratio of organic silicate, nano-silicon dioxide and hydrochloric acid solution is 1:1-3:0.05-0.15, and the mass fraction of magnesium fluoride in the magnesium fluoride acid hydrolysis solution is 0.1%-1%; Step 2: Adding a mixed alcohol solution and a nano titanium dioxide sol to a mixed sol material to obtain a nano silicon-titanium compound complexed magnesium fluoride sol; the three are mixed in a ratio range of 1:2-5:0.1-0.5; the mixed alcohol solution includes a mixture of any one or more of ethanol, methanol, isopropanol, propylene glycol methyl ether, and n-propanol, and a dispersant; wherein the dispersant accounts for 0.1%-0.5%; Step 3: placing the substrate in acetone and deionized water for ultrasonic cleaning in turn, and drying; taking the nano-silicon-titanium compound complexed magnesium fluoride sol prepared in step 2, coating it on the substrate, and then standing it to dry, to obtain a self-cleaning nano coating; Among them, the particle size of nano-silicon dioxide ranges from 10-50 nm; In step 3, the power of ultrasonic cleaning is 300 W and the time is 5 min-10 min; the standing time is 3-10 h; the coating process includes scraping, sponge rubbing, solution dipping, gravity coating or pressure spraying.

2. A self-cleaning nano coating suitable for photovoltaic modules, characterized in that: The self-cleaning nano coating is prepared by the preparation method as claimed in claim 1; the thickness of the self-cleaning nano coating is in the range of 160-175 nm.

3. An application of the self-cleaning nano coating suitable for photovoltaic modules prepared by the preparation method according to claim 1 in the field of dustproof, self-cleaning, anti-reflection or anti-radiation coating.

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