Self-cleaning antireflection coating and preparation method thereof
By combining TiO2 and tin-antimony oxide to coat hollow SiO2 with an inorganic binder, a core-shell structure coating is formed, which solves the problem of poor durability of self-cleaning coatings for photovoltaic glass in outdoor environments, and achieves efficient self-cleaning and improved mechanical strength.
Patent Information
- Application Number
- CN202511928370.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-10
AI Technical Summary
Existing self-cleaning coatings for photovoltaic glass have poor durability in outdoor environments, making it difficult to balance photocatalytic activity, antistatic properties, mechanical properties, and optical properties, and they are not effective at cleaning bird droppings.
A core-shell structure coating is formed by combining 0-55% TiO2 to coat hollow SiO2, 0-55% tin-antimony oxide to coat hollow SiO2, and 45-60% inorganic binder. The mechanical strength is enhanced by low-temperature curing, and the self-cleaning effect is improved by utilizing the hollow structure.
It achieves a balance between the optical properties and photocatalytic activity of the coating, enhances antistatic properties and mechanical strength, improves the self-cleaning effect on bird droppings, reduces material costs, and facilitates large-scale production.
Smart Images
Figure CN121825288A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of functional nano coating, and particularly relates to a self-cleaning anti-reflection coating and a preparation method thereof. BACKGROUND
[0002] As a key encapsulation material of photovoltaic modules, the surface cleanliness of photovoltaic glass directly affects the solar light transmission ratio, and further determines the power generation efficiency. Surface pollutants can reduce the power generation capacity of photovoltaic modules, and long-term accumulation can cause hot spots in the modules, and even cause fires in severe cases.
[0003] In the vicinity of bird habitat activity area, bird droppings are more harmful to photovoltaic modules. Bird droppings are high in water content, high in viscosity, strong in adhesion, and uneven in distribution, and are more likely to cause hot spots, and have a greater impact on module power generation. Moreover, bird droppings contain corrosive substances such as uric acid, ammonium, and phosphate, which can cause chemical corrosion of the glass surface of photovoltaic modules over a long period of time, reducing the service life of photovoltaic modules and increasing the cost of replacement and maintenance.
[0004] Traditional manual cleaning is subject to high labor costs and water shortages; robotic automatic cleaning equipment is high in cost and difficult to operate, and is also subject to geographical and natural environmental constraints. Coating a self-cleaning nano coating on the surface of photovoltaic glass can solve this problem, and this technology is gradually becoming an important solution in the industry and has been selected as a national key low-carbon technology for promotion.
[0005] The forces between dust, bird droppings and other pollutants and the glass surface mainly include gravity, capillary force, van der Waals force, and electrostatic force, which are affected by the surface roughness, surface energy, and surface resistance of the coating. Self-cleaning coating can reduce the force between dust, bird droppings and other pollutants and the glass, and remove dust, bird droppings and other pollutants through rainwater in nature.
[0006] Currently, photovoltaic self-cleaning nano coatings have two major technical branches: hydrophobic / superhydrophobic coatings and hydrophilic / superhydrophilic coatings. Hydrophobic / superhydrophobic coatings are easily damaged by ultraviolet light and acid rain in outdoor environments, leading to rapid degradation of hydrophobic properties, and their nano structures are also easily damaged by natural wind and sand erosion, resulting in poor durability. Hydrophilic / superhydrophilic self-cleaning coatings mainly use nano SiO2 and TiO2 as core functional materials, and nano particles with specific particle size and morphology are used to construct a microstructure surface with a certain roughness, reducing the adsorption of dust, bird droppings and other pollutants; the surface of nano SiO2 and TiO2 has a large number of hydroxyl groups that can form a hydrophilic layer, achieving rainwater flushing self-cleaning; TiO2 has photocatalytic activity and can produce a large number of active hydroxyl groups under the excitation of ultraviolet light in outdoor environments, decomposing surface organic pollutants and maintaining long-term hydrophilicity of the coating. Antistatic performance is mainly achieved by introducing conductive agents, which can reduce the surface resistance of the coating and reduce or eliminate the electrostatic adsorption of pollutants on the glass surface.
[0007] In the hydrophilic / super-hydrophilic coating, the super-hydrophilic performance of the pure nano-SiO2 coating is not durable, the hydroxyl groups on the coating surface fall off after being exposed to the outdoor environment for a period of time, and the water contact angle increases to more than 30°. In the environment with more organic pollutants, the SiO2 coating adsorbs the organic matters in the environment, and the hydrophilic performance and self-cleaning performance further decrease. The existing technology usually adds TiO2 in the formula to give the coating photocatalytic activity, maintain the super-hydrophilic property and self-cleaning performance for a long time, but this leads to the decrease of the solar light transmission ratio of the coating: the refractive index of TiO2 is 2.50~2.80, which is much higher than the refractive index of glass (1.49~1.52), and the solar light reflection is increased, the photovoltaic module power generation is affected, and it is difficult to balance the photocatalytic performance and optical performance. In addition, TiO2 has high activity, poor stability in the formula, easy to agglomerate, and compatibility problems with SiO2 in the formula, and the formula product cannot be stored for a long time.
[0008] The antistatic performance is obtained by using a conductive agent, the organic high molecular conductive agent has poor outdoor durability, and inorganic conductive agents such as ATO and ITO are mainly used, and the refractive index of the inorganic conductive agents is also high (1.90~2.10), and it is difficult to balance the electrical performance and optical performance. In order to reduce the refractive index and improve the optical performance of the coating, the current technology mainly uses mesoporous or chain-like SiO2 to finally form a porous nano-SiO2 and TiO2 composite coating, and the particles in the coating and the particles and the base glass are mainly in loose point contact, and the binding force is limited, and the mechanical strength is not high.
[0009] The existing technology patents are mainly self-cleaning coatings for ordinary dust, and there is a lack of targeted technology for bird droppings which contain a lot of water and have high viscosity and strong adhesion. The hydrophobic / super-hydrophobic coating can reduce the adhesion of bird droppings due to its low surface energy characteristics in the early stage, but when bird droppings are gathered in a large area, the coating is hydrophobic, which is not conducive to the infiltration of rainwater, cannot be washed away by rainwater, and has the defect of outdoor weather resistance.
[0010] Therefore, it is urgent to develop a coating which is targeted at bird droppings and meets the comprehensive requirements of high photocatalytic activity, excellent antistatic performance, good antireflection effect, stable mechanical performance, chemical corrosion resistance and outdoor durability. SUMMARY
[0011] The present application aims to at least solve one of the problems in the related art. To this end, an embodiment of the present application proposes a self-cleaning antireflection coating.
[0012] The self-cleaning anti-reflective coating of the embodiment of the present application comprises: 0-55 % TiO2 coated hollow SiO2, 0-55 % tin antimony oxide coated hollow SiO2 and 45-60 % inorganic adhesive, in terms of mass percentage, wherein the TiO2 coated hollow SiO2 and the tin antimony oxide coated hollow SiO2 cannot be 0 at the same time, and the sum of the mass of the TiO2 coated hollow SiO2 and the tin antimony oxide coated hollow SiO2 does not exceed 60 %.
[0013] The self-cleaning anti-reflective coating of the embodiment of the present application has the advantages and technical effects that: 1. In the embodiment of the present application, the TiO2 coated hollow SiO2 avoids the agglomeration of TiO2 in the liquid phase, realizes the compatibility and stability between the core nanoparticles, and balances the optical performance and photocatalytic activity; 2. In the embodiment of the present application, the tin antimony oxide coated hollow SiO2 makes the coating obtain the antistatic property, and the particles with core-shell structure also realize the compatibility and stability, and balance the optical performance and electrical performance; the antistatic property reduces the electrostatic adsorption of outdoor dust on the surface of the component, and further improves the self-cleaning effect of the coating; 3. In the embodiment of the present application, the added inorganic adhesive is filled between the nanoparticles and between the substrate and the nanoparticles, can be cured at low temperature, increases the connection between the nanoparticles and between the nanoparticles and the substrate glass, improves the mechanical strength of the coating, and significantly enhances the hardness, adhesion to the substrate and wear resistance of the coating; 4. In the embodiment of the present application, the material cost is low, the production process is simple, the use of strong acid and strong base and high temperature conditions is avoided, and the large-scale production is facilitated.
[0014] In some embodiments, the hollow SiO2 has a particle size of 50-100 nm and a wall thickness of 5-15 nm; And / or, the mass percentage of TiO2 in the TiO2 coated hollow SiO2 is 5-15 %; And / or, the mass percentage of tin antimony oxide in the tin antimony oxide coated hollow SiO2 is 5-15 %; And / or, the inorganic adhesive is a chain polysiloxane; And / or, the thickness of the self-cleaning anti-reflective coating is 100-150 nm.
[0015] The embodiment of the present application also provides a preparation method of the above-mentioned self-cleaning anti-reflective coating, which comprises the following steps: preparing hollow SiO2, then respectively preparing TiO2 coated hollow SiO2, tin antimony oxide coated hollow SiO2 and inorganic adhesive, mixing the prepared TiO2 coated hollow SiO2, tin antimony oxide coated hollow SiO2, inorganic adhesive, deionized water and ethanol in proportion to form a plating solution, coating on the surface of the substrate, and naturally drying to form a self-cleaning anti-reflective coating.
[0016] In some embodiments, the method for preparing the hollow SiO2 comprises the following steps: (11) ZnO powder is dispersed in an ethanol aqueous solution with a mass concentration of 70-90%, and stirred for 30-50 min to disperse uniformly, then ammonia water is added to adjust the pH, and stirring is continued for 30-50 min; (12) TMOS is dissolved in ethanol and added to the mixture obtained in step (11), and after stirring and reaction, strong acid cation exchange resin is added for ion exchange treatment; (13) After the ion exchange treatment in step (12) is completed, 500-700 mesh filter cloth is used for filtration, the obtained filtrate is filtered through a 5-15 nm ceramic membrane, washed with deionized water, concentrated, and the solid content is adjusted to obtain a hollow SiO2 dispersion.
[0017] In some embodiments, in step (11), the particle size of the ZnO powder is 30-70 nm, the stirring speed is 200-500 rpm, and the pH is adjusted to 7-9; And / or, in step (12), the mass ratio of TMOS to ZnO powder is (2-3):1; the addition speed of the TMOS ethanol solution is 30-70 g / min; the stirring reaction time is 10-15 h, the total exchange amount of the strong acid cation exchange resin is 2-6 times the amount of substance of ZnO; and the ion exchange treatment time is 10-15 h; And / or, in step (13), the solid content of the hollow SiO2 dispersion is 3-7%.
[0018] In some embodiments, the method for preparing the TiO2-coated hollow SiO2 comprises the following steps: (21) Hollow SiO2 dispersion is added to a reaction kettle, and under stirring conditions, ethanol is added to the reaction kettle, then acetic acid is added to adjust the pH, and the temperature is raised to 50-80 ℃; (22) Butyl titanate is dissolved in ethanol and added dropwise to the reaction kettle in step (21), and after stirring, it is transferred to an autoclave for solvothermal reaction; (23) After the solvothermal reaction is completed, the temperature is lowered to room temperature, 500-700 mesh filter cloth is used for filtration to obtain a TiO2-coated hollow SiO2 dispersion with a solid content of 3-5%.
[0019] In some embodiments, in step (21), the stirring speed is 200-500 rpm, the mass ratio of the hollow SiO2 dispersion to ethanol is (4-6):1, and the pH is adjusted to 2-4; And / or, in the step (22), the mass ratio of the butyl titanate and ethanol is 1: (1-2), the mass ratio of the butyl titanate and the hollow SiO2 dispersion liquid is 1: (30-50), and the stirring treatment time is 8-15 h; the solvothermal reaction temperature is 150-200 ℃, and the solvothermal reaction time is 10-15 h.
[0020] In some embodiments, the preparation method of the hollow SiO2 coated with the tin antimony oxide comprises: (31) adding the hollow SiO2 dispersion liquid into a reaction kettle, adding a NaCO3 solution to adjust the pH value, and then adding an aqueous solution of Na2[Sn(OH)6] into the reaction kettle under stirring treatment for 20-50 min, and then adding an aqueous solution of NaSbO3 for continuous stirring for 20-50 min; (32) filtering the system obtained in the step (31) through 500-700 mesh filter cloth, transferring the filtrate into a hydrothermal high-pressure kettle, and then performing hydrothermal reaction, and then sequentially filtering through an 8-12 nm ceramic membrane, washing, concentrating, and adjusting the pH value to 2-4 through acetic acid to adjust the solid content, and finally obtaining the ATO coated hollow SiO2 dispersion liquid with a solid content of 3-5 %.
[0021] In some embodiments, in the step (31), the concentration of the NaCO3 solution is 0.5-2 %, the pH value is adjusted to 7-9, and the stirring treatment speed is 200-500 rpm; the mass ratio of the hollow SiO2, Na2[Sn(OH)6] and NaSbO3 is (30-70): (7-9): 1. And / or, in the step (32), the hydrothermal reaction temperature is 200-400 ℃, and the hydrothermal reaction time is 8-12 h.
[0022] In some embodiments, the preparation method of the inorganic binder comprises: adding ethanol and TEOS into a reaction kettle, stirring uniformly, then heating to 50-70 ℃, adding deionized water and acetic acid for reaction, cooling to room temperature after the reaction is completed, and then performing aging treatment. Preferably, the mass ratio of the ethanol, TEOS, deionized water and acetic acid is (6-8): (1-1.5): 1: (0.2-0.5); the stirring speed is 200-400 rpm; the reaction time is 10-15 h, the aging treatment time is 60-80 h, and the solid content of the inorganic binder is 3-5 %. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 is an effect picture of the bird droppings prevention performance of the coating prepared in Example 1. DETAILED DESCRIPTION
[0024] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.
[0025] The self-cleaning anti-reflective coating of the embodiments of the present application comprises: 0-55 % TiO2 coated hollow SiO2, 0-55 % antimony tin oxide coated hollow SiO2 and 45-60 % inorganic adhesive, in terms of mass percentage, wherein the TiO2 coated hollow SiO2 and the antimony tin oxide coated hollow SiO2 cannot be 0 at the same time, and the sum of the mass of the TiO2 coated hollow SiO2 and the antimony tin oxide coated hollow SiO2 does not exceed 60 %.
[0026] The self-cleaning anti-reflective coating of the embodiments of the present application has the advantages and technical effects that: 1. In the embodiments of the present application, the TiO2 coated hollow SiO2 avoids the agglomeration of TiO2 in the liquid phase, realizes the compatibility and stability between the core nanoparticles, and balances the optical performance and photocatalytic activity; 2. In the embodiments of the present application, the antimony tin oxide coated hollow SiO2 makes the coating obtain the antistatic property, and the core-shell structure particles also realize the compatibility and stability, and balance the optical performance and electrical performance; the antistatic property reduces the static adsorption of outdoor dust on the surface of the component, and further improves the self-cleaning effect of the coating; 3. In the embodiments of the present application, the added inorganic adhesive is filled between the nanoparticles and between the substrate and the nanoparticles, can be cured at low temperature, increases the connection between the nanoparticles and between the nanoparticles and the substrate glass, improves the mechanical strength of the coating, and significantly enhances the hardness, adhesion to the substrate and wear resistance of the coating; 4. In the embodiments of the present application, the material cost is low, the production process is simple, the use of strong acid and strong base and high temperature conditions is avoided, and the large-scale production is facilitated.
[0027] In some embodiments, preferably, the particle size of the hollow SiO2 is 50-100 nm, and the wall thickness is 5-15 nm.
[0028] The present application constructs a special concave-convex structure surface by using the hollow particles with a specific particle size range. When the bird droppings adhere to the surface of the component, there are a large number of holes and gaps between the bird droppings and the glass, and the contact area is greatly reduced. The lower surface of the holes and gaps is the SiO2 / TiO2 composite particles with a large number of active hydroxyl groups, which can be quickly wetted and flowed when it rains, forming a micro water flow path to accelerate the rainwater to wash away the bird dropping pollutants.
[0029] In some embodiments, preferably, the mass percentage of TiO2 in the TiO2 coated hollow SiO2 is 5-15 %. And / or, the mass ratio of the antimony tin oxide in the antimony tin oxide coated hollow SiO2 is 5-15%. And / or, the inorganic adhesive is chain polysiloxane. And / or, the thickness of the self-cleaning anti-reflective coating is 100-150 nm.
[0030] Further preferably, the mass ratio of the TiO2 in the TiO2 coated hollow SiO2 is 8-12%. And / or, the mass ratio of the antimony tin oxide in the antimony tin oxide coated hollow SiO2 is 8-12%. And / or, the thickness of the self-cleaning anti-reflective coating is 110-130 nm.
[0031] The embodiment of the present application also provides a preparation method of the self-cleaning anti-reflective coating, which comprises the following steps: preparing hollow SiO2, then respectively preparing TiO2 coated hollow SiO2, antimony tin oxide coated hollow SiO2 and inorganic adhesive, mixing the prepared TiO2 coated hollow SiO2, antimony tin oxide coated hollow SiO2, inorganic adhesive, deionized water and ethanol in proportion to form a coating liquid, coating on the surface of a substrate, and naturally drying to form a self-cleaning anti-reflective coating.
[0032] In some embodiments, preferably, the preparation method of the hollow SiO2 comprises the following steps: (11) dispersing ZnO powder in an ethanol aqueous solution with a mass concentration of 70-90%, uniformly dispersing after stirring treatment for 30-50 min, adding ammonia water to adjust pH, and continuing stirring treatment for 30-50 min; (12) dissolving TMOS in ethanol and adding to the mixture obtained in the step (11), adding strong acid type cation exchange resin for ion exchange treatment after stirring reaction; (13) after the ion exchange treatment in the step (12) is completed, first filtering with 500-700 mesh filter cloth, filtering the obtained filtrate through a 5-15 nm ceramic membrane, washing with deionized water, concentrating, and adjusting solid content to obtain a hollow SiO2 dispersion liquid.
[0033] In some embodiments, preferably, in the step (11), the particle size of the ZnO powder is 30-70 nm, the stirring speed is 200-500 rpm, and the pH is adjusted to 7-9. And / or, in the step (12), the mass ratio of the TMOS and ZnO powder is (2-3):1; the adding speed of the TMOS ethanol solution is 30-70 g / min; the stirring reaction time is 10-15 h, the total exchange amount of the strong acid type cation exchange resin is 2-6 times of the ZnO amount of substance; the ion exchange treatment time is 10-15 h; And / or, in the step (13), the solid content of the hollow SiO2 dispersion liquid is 3-7%.
[0034] In some embodiments, preferably, the preparation method of the TiO2 coated hollow SiO2 specifically comprises the following steps: (21) hollow SiO2 dispersion liquid is added to the reaction kettle, ethanol is added to the reaction kettle under stirring, and then the pH is adjusted by adding acetic acid, and the temperature is increased to 50-80 ℃; (22) butyl titanate is dissolved in ethanol, and then added dropwise to the reaction kettle in step (21), and then transferred to an autoclave after stirring treatment for solvothermal reaction; (23) after the solvothermal reaction is completed, the temperature is reduced to room temperature, and a 500-700 mesh filter cloth is used to filter to obtain a TiO2 coated hollow SiO2 dispersion liquid with a solid content of 3-5%.
[0035] In the embodiments of the present application, low-cost ZnO is used as a template agent to prepare hollow SiO2, and a simple sol-gel method and a hydrothermal method are used to prepare TiO2 coated hollow SiO2, which avoids high-temperature processes and also avoids the agglomeration of TiO2 in the liquid phase, realizes the compatibility and stability between the core nanoparticles, and balances the optical properties and photocatalytic activity.
[0036] In some embodiments, preferably, in the step (21), the stirring speed is 200-500 rpm, the mass ratio of the hollow SiO2 dispersion liquid and ethanol is (4-6):1, and the pH is adjusted to 2-4. And / or, in the step (22), the mass ratio of the butyl titanate and ethanol is 1:(1-2), the mass ratio of the butyl titanate and the hollow SiO2 dispersion liquid is 1:(30-50), and the stirring treatment time is 8-15 h; the solvothermal reaction temperature is 150-200 ℃, and the solvothermal reaction time is 10-15 h.
[0037] In some embodiments, preferably, the preparation method of the tin antimony oxide coated hollow SiO2 comprises: (31) adding hollow SiO2 dispersion liquid into a reaction kettle, adding NaCO3 solution to adjust pH value; under stirring treatment, adding aqueous solution of Na2[Sn(OH)6] into the reaction kettle, stirring for 20-50 min, then adding aqueous solution of NaSbO3 and continuing to stir for 20-50 min; (32) filtering the system obtained in step (31) through 500-700 mesh filter cloth, transferring the filtrate into a hydrothermal high-pressure kettle, carrying out hydrothermal reaction, then filtering through 8-12 nm ceramic membrane, washing, concentrating, adjusting pH value to 2-4 with acetic acid, and adjusting solid content, finally obtaining ATO-coated hollow SiO2 dispersion liquid with solid content of 3-5 %.
[0038] In the embodiment of the application, ATO-coated hollow SiO2 is prepared by hydrothermal method, so that the coating layer has antistatic property, the core-shell structure particles also realize compatibility and stability, and balance is realized in optical and electrical properties, the antistatic property reduces static adsorption of outdoor dust on the surface of the component, and further improves the self-cleaning effect of the coating layer. The hollow particles are subjected to hydrothermal treatment, the surface is densified, and the internal hollow structure is relatively isolated and closed. The external adhesive is filled, the internal hollow structure is closed, the migration of pollutants and ions is blocked, and the corrosion resistance of the coating layer and the weather resistance and durability in various harsh environments are improved.
[0039] In some embodiments, preferably, in step (31), the concentration of the NaCO3 solution is 0.5-2 %, the pH value is adjusted to 7-9, and the stirring speed is 200-500 rpm; the mass ratio of hollow SiO2, Na2[Sn(OH)6] and NaSbO3 is (30-70):(7-9):1. And / or, in step (32), the hydrothermal reaction temperature is 200-400 ℃, and the hydrothermal reaction time is 8-12 h.
[0040] In some embodiments, the preparation method of the inorganic adhesive comprises: adding ethanol and TEOS into a reaction kettle, stirring uniformly, then heating to 50-70 ℃, adding deionized water and acetic acid for reaction, cooling to room temperature after the reaction is completed, and carrying out aging treatment. Preferably, the mass ratio of the ethanol, TEOS, deionized water and acetic acid is (6-8):(1-1.5):1:(0.2-0.5); the stirring speed is 200-400 rpm; the reaction time is 10-15 h, the aging treatment time is 60-80 h, and the solid content of the inorganic adhesive is 3-5 %.
[0041] The technical solutions of the application will be described in detail below in combination with specific embodiments and drawings.
[0042] The TiO2-coated hollow SiO2, the tin antimony oxide-coated hollow SiO2 and the inorganic adhesive used in the embodiments of the present application are prepared, specifically: Preparation of hollow SiO2: 8.0 kg of ethanol and 2.0 kg of deionized water are mixed in a reaction kettle, stirred at 300 rpm, 0.5 kg of ZnO powder (particle size 50 nm) is added, stirred for 30 min, uniformly dispersed, ammonia water is added to adjust the pH value to 8.5, and stirring is continued for 30 min. 1.27 kg of TMOS and 4.73 kg of ethanol are mixed and then added to the kettle at a speed of 50 g / min, and the addition is completed in 2 h, and the stirring reaction is continued for 12 h. Strong acid cation exchange resin (2 times excess) is added and treated for 12 h. Filtered through 600 mesh filter cloth, and the filtrate is filtered through a 10 nm ceramic membrane, washed with deionized water, concentrated, and the solid content is adjusted, to obtain a hollow SiO2 dispersion with a solid content of 5%, a particle size of about 70 nm, and a wall thickness of 10 nm.
[0043] Preparation of TiO2-coated hollow SiO2: 8 kg of hollow SiO2 dispersion (5%) is added to a reaction kettle, stirred at 300 rpm, 1.5 kg of ethanol is added, and acetic acid is used to adjust the pH value to 3.0, the temperature is raised to 70°C, 0.17 kg of butyl titanate is dissolved in 0.33 kg of ethanol, and then added dropwise to the reaction kettle, and after the addition is completed, stirring is continued for 10 h, and then transferred to a high-pressure kettle, and hydrothermal / solvothermal reaction is carried out at 180°C for 12 h. After the temperature is lowered to room temperature, 600 mesh filter cloth is used for filtration to obtain a TiO2-coated hollow SiO2 dispersion with photocatalytic activity, and the solid content is about 4.4% (of which SiO2 is 4% and TiO2 is 0.4%).
[0044] Preparation of tin antimony oxide-coated hollow SiO2: 8 kg of hollow SiO2 dispersion (5%) is added to a reaction kettle, 1% NaCO3 solution is used to adjust the pH value to 8.5, and stirring is carried out at 300 rpm, 59.00 g of Na2[Sn(OH)6] is dissolved in 1700 g of deionized water, and then added to the reaction kettle, after stirring for 30 min, 8.00 g of NaSbO3 is dissolved in 233 g of deionized water, and then added to the reaction kettle, and stirring is continued for 30 min. After filtration through 600 mesh filter cloth, it is transferred to a hydrothermal high-pressure kettle, and hydrothermal reaction is carried out at 240°C for 10 h, and then washed with a 10 nm ceramic membrane, concentrated, adjusted to a pH value of 3.0 with acetic acid, and the solid content is adjusted, to obtain a hollow SiO2 dispersion coated with ATO with antistatic properties, with a solid content of 4.4% (of which SiO2 is 4% and ATO is 0.4%).
[0045] The preparation reaction kettle of inorganic adhesive was added with 7.21 kg of ethanol, 1.39 kg of TEOS, 300 rpm stirring, heating to 65℃, 1 kg of deionized water and 0.4 kg of acetic acid were mixed and added into the reaction kettle, reaction for 12 h, cooling to room temperature, aging for 72 h, to obtain the dispersion of inorganic adhesive (solid content 4%).
[0046] Example 1 Take 20 % TiO2coated hollow SiO2(4.4%) dispersion, 20% ATO coated hollow SiO2(4.4%) dispersion, 5% deionized water, 15% ethanol, 40% inorganic adhesive dispersion, mix evenly to obtain a layer plating solution, spray on the surface of the substrate, dry to form a self-cleaning anti-reflective coating with a thickness of 120 nm, wherein the substrate is photovoltaic embossed glass, the solar light transmission ratio T = 91.8% (AM1.5 380~1100nm).
[0047] The coating prepared in this example was tested for bird droppings resistance, and the results are shown in Figure 1 From Figure 1 It can be seen that the glass treated by the coating has no bird droppings residue after washing with clean water, and has very good bird droppings resistance.
[0048] Examples 2~6 Examples 2~6 and Example 1 are different only in the content of each substance, and the specific formula is shown in Table 1.
[0049] Comparative Example 1 Mix 40% hollow SiO2dispersion, 0.08% P25 commercial TiO2, 3.32% deionized water, 1.6% commercial ATO, 15% ethanol, 40% inorganic binder evenly to obtain a plating solution, which is coated on the surface of the substrate, dried to form a self-cleaning anti-reflective coating with a thickness of 120 nm.
[0050] Comparative Example 2 Mix 40% hollow SiO2dispersion, 1.8% deionized water, 3.2% commercial ATO dispersion, 15% ethanol, 40% inorganic binder evenly to obtain a plating solution, which is coated on the surface of the substrate, dried to form a self-cleaning anti-reflective coating with a thickness of 120 nm.
[0051] Comparative Example 3 Mix 40% hollow SiO2dispersion, 0.16% P25 commercial TiO2, 4.84% deionized water, 15% ethanol, 40% inorganic binder evenly to obtain a plating solution, which is coated on the surface of the substrate, dried to form a self-cleaning anti-reflective coating with a thickness of 120 nm.
[0052] Comparative Example 4 Take 25 % TiO2coated hollow SiO2(4.4%) dispersion, 25% ATO coated hollow SiO2(4.4%) dispersion, 5% deionized water, 15% ethanol, 30% inorganic adhesive dispersion, mix evenly to get a layer plating solution, spray on the surface of the substrate, dry to form a self-cleaning anti-reflective coating with a thickness of 120 nm, wherein the substrate is photovoltaic textured glass, and the solar light transmission ratio T = 91.8% (AM1.5 380~1100nm).
[0053] Table 1
[0054] The coatings prepared in Examples 1-6 and Comparative Examples 1-4 were tested for relevant properties, and the results are shown in Table 2.
[0055] Table 2
[0056] Note: In Table 2, the adhesion test is based on standard GB / T 9286-2021 / ISO2409:2020, where 0 grade is the best adhesion grade.
[0057] The abrasion resistance test is based on standard GB / T 23988-2009.
[0058] The high pressure cooking (PCT) experiment refers to the standard: T / CPIA 0028.1-2024 "Glass for Photovoltaic Modules - Part 1 Front Plate Anti-Reflective Film Glass", the sample is placed in a high pressure cooking aging test box, the test conditions are as follows: test temperature 121℃±0.5℃, relative humidity 99%~100%, test time 48h, to determine the attenuation of photovoltaic transmission ratio Tr and the appearance change of front plate anti-reflective film glass after high temperature, high pressure and high humidity.
[0059] The xenon lamp aging test refers to ASTM G155-25 Nonmetallic Materials Exposure to Xenon Arcs.
[0060] The neutral salt spray test refers to GB / T 1771-2008 Determination of Resistance to Neutral Salt Spray of Paints and Varnishes.
[0061] Acidic phosphate / alkaline phosphate refers to placing the sample in an acidic phosphate / alkaline phosphate solution, respectively, and soaking at 25℃ for 48h, wherein the acidic phosphate is NaH2PO3(1moL / L) + hydrochloric acid (1moL / L), and the alkaline phosphate is Na3PO3(1moL / L) + ammonia water (1moL / L).
[0062] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising, but not limited to, any indicated features, integers, steps or components. It is also to be understood that the terminology "comprising" can be replaced by the terminology "consisting of" or "consisting essentially of" in some embodiments or examples.
[0063] Although the above-mentioned embodiments have been shown and described, it is to be understood that the above-mentioned embodiments are exemplary, and should not be understood as limiting the present disclosure, and the changes, modifications, replacements and variations of the above-mentioned embodiments made by those skilled in the art are within the protection scope of the present disclosure.
Claims
1. A self-cleaning anti-reflective coating, characterized in that, include: 0~55% TiO2 coated hollow SiO2, 0~55% tin-antimony oxide coated hollow SiO2, and 45~60% inorganic binder, by mass percentage, wherein the TiO2 coated hollow SiO2 and the tin-antimony oxide coated hollow SiO2 cannot both be 0, and the sum of the masses of TiO2 coated hollow SiO2 and tin-antimony oxide coated hollow SiO2 does not exceed 60%.
2. The self-cleaning antireflective coating according to claim 1, characterized in that, The hollow SiO2 has a particle size of 50~100 nm and a wall thickness of 5~15 nm; And / or, the mass percentage of TiO2 in the TiO2-coated hollow SiO2 is 5-15%; And / or, the mass percentage of tin oxide and antimony oxide in the hollow SiO2 coated with tin oxide is 5% to 15%; And / or, the inorganic adhesive is a chain-like polysiloxane; And / or, the thickness of the self-cleaning antireflective coating is 100~150nm.
3. The method for preparing the self-cleaning antireflective coating according to claim 1 or 2, characterized in that, Includes the following steps: Hollow SiO2 dispersion was prepared, and then TiO2-coated hollow SiO2 dispersion, tin-antimony oxide-coated hollow SiO2 dispersion, and inorganic binder were prepared separately. The prepared TiO2-coated hollow SiO2, tin-antimony oxide-coated hollow SiO2, inorganic binder, deionized water and ethanol were mixed evenly in proportion to form a coating solution, which was then coated on the surface of the substrate. After natural drying, a self-cleaning antireflective coating was formed.
4. The method for preparing the self-cleaning antireflective coating according to claim 3, characterized in that, The method for preparing hollow SiO2 includes the following steps: (11) Disperse ZnO powder in an ethanol aqueous solution with a mass concentration of 70~90%, stir for 30~50 min until the dispersion is uniform, add ammonia water to adjust the pH, and continue stirring for 30~50 min. (12) Dissolve TMOS in ethanol and add it to the mixture obtained in step (11). After stirring the reaction, add a strong acid cation exchange resin for ion exchange treatment. (13) After the ion exchange treatment in step (12) is completed, the solution is first filtered with a 500-700 mesh filter cloth, and the obtained filtrate is filtered through a 5-15 nm ceramic membrane, washed with deionized water, concentrated, and the solid content is adjusted to obtain a hollow SiO2 dispersion.
5. The method for preparing the self-cleaning antireflective coating according to claim 4, characterized in that, In step (11), the particle size of the ZnO powder is 30~70nm, the stirring speed is 200~500rpm, and the pH is adjusted to 7~9. And / or, in step (12), the mass ratio of TMOS to ZnO powder is (2~3):1; the addition rate of the ethanol solution of TMOS is 30~70 g / min; the stirring reaction time is 10~15 h; the exchange capacity of the strong acid cation exchange resin is 2~6 times the amount of ZnO; and the ion exchange treatment time is 10~15 h. And / or, in step (13), the solid content of the hollow SiO2 dispersion is 3~7%.
6. The method for preparing the self-cleaning antireflective coating according to claim 3, characterized in that, The preparation method of TiO2-coated hollow SiO2 specifically includes the following steps: (21) Add hollow SiO2 dispersion to the reactor, add ethanol to the reactor under stirring, then add acetic acid to adjust the pH, and then raise the temperature to 50~80 ℃. (22) After dissolving tetrabutyl titanate in ethanol, add it dropwise to the reaction vessel described in step (21), stir and then transfer it to a high-pressure vessel for solvothermal reaction; (23) After the solvothermal reaction is completed, the mixture is cooled to room temperature and filtered through a 500-700 mesh filter cloth to obtain a TiO2-coated hollow SiO2 dispersion with a solid content of 3-5%.
7. The method for preparing the self-cleaning antireflective coating according to claim 6, characterized in that, In step (21), the stirring speed is 200~500 rpm, the mass ratio of the hollow SiO2 dispersion to ethanol is (4~6):1, and the pH is adjusted to 2~4. And / or, in step (22), the mass ratio of tetrabutyl titanate to ethanol is 1:(1~2), the mass ratio of tetrabutyl titanate to hollow SiO2 dispersion is 1:(30~50), the stirring time is 8~15 h, the temperature of the solvothermal reaction is 150~200℃, and the time of the solvothermal reaction is 10~15 h.
8. The method for preparing the self-cleaning antireflective coating according to claim 3, characterized in that, The method for preparing the tin-antimony oxide-coated hollow SiO2 includes: (31) Add hollow SiO2 dispersion to the reactor and add NaCO3 solution to adjust the pH value; under stirring, add Na2[Sn(OH)6] aqueous solution to the reactor and stir for 20~50 min, then add NaSbO3 aqueous solution and continue stirring for 20~50 min; (32) After filtering the system obtained in step (31) through a 500-700 mesh filter cloth, the filtrate is transferred to a hydrothermal autoclave for hydrothermal reaction. Then, the system is filtered, washed, concentrated, and the pH value is adjusted to 2-4 with acetic acid in sequence to adjust the solid content. Finally, an ATO-coated hollow SiO2 dispersion with a solid content of 3-5% is obtained.
9. The method for preparing the self-cleaning antireflective coating according to claim 8, characterized in that, In step (31), the concentration of the NaCO3 solution is 0.5-2%, the pH is adjusted to 7-9, and the stirring speed is 200-500 rpm; the mass ratio of hollow SiO2, Na2[Sn(OH)6] and NaSbO3 is (30-70):(7-9):
1. And / or, in step (32), the temperature of the hydrothermal reaction is 200~400 ℃ and the time of the hydrothermal reaction is 8~12h.
10. The method for preparing the self-cleaning antireflective coating according to claim 3, characterized in that, The preparation method of the inorganic binder includes: adding ethanol and TEOS to a reaction vessel, stirring evenly, heating to 50~70℃, adding deionized water and acetic acid to react, and cooling to room temperature for aging after the reaction is completed. Preferably, the mass ratio of ethanol, TEOS, deionized water and acetic acid is (6~8):(1~1.5):1:(0.2~0.5); the stirring speed is 200~400 rpm; the reaction time is 10~15h; the aging treatment time is 60~80h; and the solid content of the inorganic binder is 3~5%.