Dynamic humidity response type antireflection coating liquid as well as preparation method and application thereof

Abstract

The invention discloses a dynamic humidity response type anti-reflection coating liquid and a preparation method and application thereof.The coating liquid is composed of SiO2 sol, a humidity response type cobalt-based complex CETA, a dispersing agent and absolute ethyl alcohol, when the environment humidity of the humidity response type cobalt-based complex CETA is increased from 30% to 60%, the visible light absorbance decreasing amplitude is larger than or equal to 50%, and the visible light absorbance decreasing amplitude is larger than or equal to 50%. Under high humidity (RH 60 + / -5%), the visible light absorbance is reduced to 0.1-0.3, the response time is less than or equal to 40 seconds, and the infrared emissivity amplification at the wave band of 8-13 microns is greater than or equal to 5%. The preparation method comprises the following steps: preparing CETA powder, pretreating SiO2 sol, dispersing the CETA powder and carrying out ultrasonic treatment. The coating liquid is sprayed on a light absorption surface of photovoltaic glass, is suitable for a high-temperature and high-humidity environment, balances light transmission and heat dissipation through dynamic humidity quick response and high infrared emissivity, and improves the power generation efficiency by 0.5% and remarkably improves the durability compared with a pure SiO2 film layer.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of coating liquids, and particularly relates to a dynamic humidity-responsive antireflection coating liquid, a preparation method thereof, and an application thereof. Background Art

[0002] As an important component of solar cell modules, the light transmittance and durability of photovoltaic glass directly affect the power generation efficiency. In a high-temperature and high-humidity environment, traditional antireflection coatings (such as pure SiO2 films) can reduce the reflectivity, but cannot dynamically adapt to humidity changes, resulting in an imbalance between light transmission and heat dissipation performance. Specifically, the film layer is prone to water vapor adsorption at high humidity, reducing the light transmittance; at the same time, the insufficient infrared emissivity leads to too high a temperature rise of the component, further affecting the power generation efficiency and the material life. In the prior art, although there are attempts to improve the infrared performance by doping metal oxides, their response speed is slow and their humidity adaptability is poor, unable to meet the requirements of dynamic humidity changes, and the film layer is prone to peeling or performance attenuation in a long-term humid and hot environment.

[0003] In addition, some dynamic response materials (such as electrochromic or thermochromic materials) are difficult to be widely applied to photovoltaic glass due to high costs and complex processes. Therefore, there is an urgent need to develop an antireflection coating liquid with both rapid humidity response, high infrared emissivity and excellent durability to solve the problems of the efficiency and stability of photovoltaic glass in high-temperature and high-humidity areas. Summary of the Invention

[0004] By providing a dynamic humidity-responsive antireflection coating liquid, a preparation method thereof, and an application thereof, the embodiments of the present application solve the problems of poor power generation efficiency and durability of photovoltaic glass in high-temperature and high-humidity areas in the prior art, and achieve the technical effects of a 0.5% increase in power generation efficiency compared with traditional pure SiO2 coating and excellent durability.

[0005] The embodiments of the present application provide a dynamic humidity-responsive antireflection coating liquid, which is composed of SiO2 sol, a humidity-responsive cobalt-based complex CETA, a dispersant, and absolute ethanol. Among them, when the environmental humidity rises from 30% to 60%, the visible light absorbance of the humidity-responsive cobalt-based complex CETA decreases by ≥50%, the visible light absorbance at high humidity drops to 0.1-0.3, the response time is ≤40 seconds, and the infrared emissivity in the 8-13 μm band increases by ≥5%.

[0006] Preferably, by weight, 75-76.5 parts of SiO2 sol, 0.5-2 parts of the humidity-responsive cobalt-based complex CETA, 0.1-0.5 parts of the dispersant, and the rest is absolute ethanol.

[0007] Preferably, the humidity-responsive cobalt-based complex CETA is prepared by a coordination reaction of cobalt chloride hexahydrate with a complexing agent ethanolamine.

[0008] Preferably, the molar ratio of cobalt chloride hexahydrate to ethanolamine is 2:1.

[0009] The embodiment of the present invention also provides a method for preparing a dynamic humidity-responsive antireflection coating solution, including the following steps:

[0010] S01 Prepare humidity-responsive cobalt-based complex CETA

[0011] Dissolve cobalt chloride hexahydrate in absolute ethanol to form a cobalt chloride / ethanol mixed solution; add ethanolamine for a coordination reaction to generate a humidity-responsive cobalt-based complex; obtain dehydrated humidity-responsive cobalt-based complex CETA powder through drying treatment.

[0012] S02 Pretreatment

[0013] Grind the humidity-responsive cobalt-based complex CETA powder prepared in step S01 to submicron level, with D50 ≤ 500 nm; mix SiO2 sol and absolute ethanol and stir magnetically for 30 min to form a homogeneous solution.

[0014] S03 Dispersion

[0015] Add the humidity-responsive cobalt-based complex CETA powder pretreated in step S02 and a dispersant into the pretreated SiO2 sol, and stir at low speed for 1 h; use a probe-type ultrasonic cleaner with a power of 200 W and a frequency of 20 kHz, treat for 30 min, and control the temperature below 25 °C; continue to stir magnetically for 2 h with a stirring speed of 500 rpm to ensure the uniform dispersion of the humidity-responsive cobalt-based complex CETA, and obtain a dynamic humidity-responsive antireflection coating solution for photovoltaic glass after stirring evenly.

[0016] The embodiment of the present invention also provides an application of the dynamic humidity-responsive antireflection coating solution, wherein the coating solution is sprayed on the light-absorbing surface of a single-sided photovoltaic glass or both sides of a double-sided photovoltaic glass, and the photovoltaic glass is used in high-temperature and high-humidity environment areas.

[0017] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects:

[0018] 1. Since a SiO2-CETA composite coating solution is prepared by mixing a humidity-responsive cobalt-based complex CETA, a dispersant, and SiO2 sol, effectively solving the problems of poor power generation efficiency and durability of photovoltaic glass in high-temperature and high-humidity areas in the prior art, improving the comprehensive performance through rapid dynamic humidity response and high infrared emissivity, and thus achieving the technical effects of a 0.5% increase in power generation efficiency and excellent durability. Description of the Drawings

[0019] Figure 1This is a physical picture of the humidity-responsive cobalt-based complex CETA powder in the first embodiment of this application;

[0020] Figure 2 This is the XRD test result of the humidity-responsive cobalt-based complex CETA powder in the first embodiment of this application, which confirms its crystal structure;

[0021] Figure 3 This is the FTIR test result of the humidity-responsive cobalt-based complex CETA powder in the first embodiment of this application, showing its characteristic functional groups;

[0022] Figure 4 This is the absorbance curve of the humidity-responsive cobalt-based complex CETA powder in an ethanol solution in the first embodiment of this application;

[0023] Figure 5 This is the absorbance curve of the humidity-responsive cobalt-based complex CETA powder in an ethanol / water mixed solution in the first embodiment of this application. Detailed implementation mode

[0024] In the embodiment of this application, by providing a dynamic humidity-responsive antireflection coating solution, a preparation method and its application, the problems of poor power generation efficiency and durability of photovoltaic glass in high-temperature and high-humidity areas in the prior art are solved, and the technical effects of a 0.5% improvement in power generation efficiency compared with traditional pure SiO2 coatings and excellent durability are achieved.

[0025] The technical solution in the embodiment of this application to solve the above problems is generally as follows:

[0026] First, a humidity-responsive cobalt-based complex CETA is prepared by oneself, and then the humidity-responsive cobalt-based complex CETA and a dispersant are added to a SiO2 sol mixture and stirred evenly to prepare a SiO2-CETA composite coating solution. Because the humidity-responsive cobalt-based complex CETA has excellent humidity-responsive characteristics, the light transmittance and heat dissipation performance are balanced through dynamic humidity rapid response and high infrared emissivity, and the film layer stability after damp heat testing is significantly better than that of pure SiO2 films.

[0027] To better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification drawings and specific implementation modes.

[0028] Example 1

[0029] Preparation of humidity-responsive cobalt-based complex CETA

[0030] Weigh 1.19 g of CoCl2·6H2O powder with a balance, select anhydrous ethanol as the solvent to dissolve the CoCl2·6H2O powder, the amount of anhydrous ethanol used is 5 ml, and stir with a magnetic stirrer at room temperature for 1 hour to obtain a cobalt chloride / ethanol mixed solution.

[0031] Dissolve 0.153 g of ethanolamine in ethanol and then add it to the cobalt chloride / ethanol mixed solution. Stir for 1 hour at room temperature. Subsequently, add 2.5 ml of deionized water to the solution and stir evenly to obtain a humidity-responsive cobalt-based complex CETA solution.

[0032] Place the humidity-responsive cobalt-based complex CETA solution in a forced-air oven at 60 °C and dry it for 6 h to obtain the target product, the humidity-responsive cobalt-based complex CETA.

[0033] Conduct a dynamic humidity response test on the humidity-responsive cobalt-based complex CETA. The test conditions are as follows:

[0034] (1) Dynamic humidity response range: 30% - 60% relative humidity (RH);

[0035] (2) Definition of response time: The time required for the absorbance / emissivity to reach a stable value (fluctuation < 5%) from the start of humidity change.

[0036] The test results are as follows

[0037] (1) Definition of response threshold:

[0038] Low humidity color development threshold: The material shows color (blue) at RH 30 ± 5%;

[0039] High humidity regulation threshold: When RH is 60 ± 5%, the visible light absorption rate decreases by ≥ 30%, and the infrared emissivity increases by ≥ 0.05.

[0040] (2) Response speed: In the range of 30% change in RH (e.g., 30% → 60%), the response time of the material ≤ 60 s, preferably ≤ 40 s.

[0041] (3) Change in visible light absorption rate:

[0042] At low humidity (RH 30 ± 5%), the average absorbance of the material in the 400 - 700 nm band is 0.4 - 0.6;

[0043] At high humidity (RH 60 ± 5%), the absorbance drops to 0.1 - 0.3, with a decrease of ≥ 50%.

[0044] (4) Dynamic range of infrared emissivity:

[0045] At low humidity (RH 30 ± 5%), the infrared emissivity in the 8 - 13 μm band is 0.85 - 0.90;

[0046] At high humidity (RH 60 ± 5%), the emissivity increases to 0.90 - 0.92, with an increase of ≥ 5%.

[0047] Example 2

[0048] Step 1: Material Preparation and Pretreatment

[0049] Weigh 100 g of SiO2 sol (solid content 5%, particle size 10 - 20 nm), 1.0 g of the humidity-responsive cobalt-based complex CETA prepared in Example 1, 0.3 g of polyethylene glycol (PEG-400) dispersant, and 38 ml of absolute ethanol. Grind the humidity-responsive cobalt-based complex CETA to the submicron level in advance, with D50 ≤ 500 nm, to reduce particle agglomeration. Mix the SiO2 sol and absolute ethanol, place it on a magnetic stirrer, and stir at a speed of 200 rpm for 30 minutes to form a homogeneous solution.

[0050] Step 2: Humidity-Responsive Cobalt-Based Complex CETA Dispersion Process and Preparation of Coating Solution

[0051] Gradually add the ground humidity-responsive cobalt-based complex CETA and polyethylene glycol dispersant to the SiO2 sol mixture, and keep stirring at a low speed (200 rpm) for 1 hour to complete the preliminary dispersion.

[0052] Subsequently, use a probe-type ultrasonic instrument to ultrasonically treat the mixture. Set the power to 200 W to ensure sufficient dispersion, the frequency to 20 kHz, and continue for 30 minutes. During the process, control the solution temperature below 25°C to avoid solvent volatilization or material decomposition. After the ultrasonic treatment, transfer the mixture to a magnetic stirrer, increase the rotation speed to 500 rpm, and continue stirring for 2 hours to ensure that the humidity-responsive cobalt-based complex CETA is uniformly dispersed in the sol. After the dispersion is completed, detect the particle size distribution by dynamic light scattering (DLS) (target D90 ≤ 800 nm), and let it stand for 24 hours to observe whether the solution layers or precipitates, to obtain the coating solution.

[0053] Example 3

[0054] Coating and Curing of Coating Solution

[0055] Take a cleaned photovoltaic glass substrate (thickness 3.2 mm), and ultrasonically clean it with acetone, deionized water, and ethanol for 10 minutes in sequence, and dry the surface with nitrogen.

[0056] Use the dipping method for coating: Immerse the substrate vertically into the coating solution in Example 2 at a speed of 10 cm / min, stay for 10 seconds, and then pull it up uniformly. Control the pulling speed at 5 - 15 cm / min to make the film thickness reach 100 - 200 nm (monitored in real time by ellipsometry). After the coating is completed, place the substrate in a blast drying oven at 80°C for 10 minutes to remove the residual solvent; then transfer it to a high-temperature oven at 150°C for 1 hour to cure and form a dense and uniform SiO2-CETA composite film layer.

[0057] Performance Optimization and Verification

[0058] The prepared composite coating solution has a light transmittance of 93.0 - 93.5% (400 - 800 nm), a reflectivity of ≤2.3% (AM1.5G), and an infrared emissivity of ≥0.92 (8 - 13 μm) in a low-humidity environment. In a high-humidity environment, the absorbance of the humidity-responsive cobalt-based complex CETA decreases, the reflectivity rises to 3.0%, and the light transmittance recovers to about 93.5%.

[0059] In the embodiments of the present invention, the balance between light transmittance and heat dissipation requirements can also be adjusted by changing the content of the humidity-responsive cobalt-based complex CETA (0.8 - 1.2 parts), or the dispersant can be replaced with a silane coupling agent (such as KH-550) to enhance the interfacial bonding.

[0060] The durability of the final film layer is verified by a damp heat cycle test (85°C / 85% RH, 1000 hours), and the actual power generation efficiency and temperature rise data of the pure SiO2 film layer in the outdoor environment are compared. The results are shown in Table 1

[0061] Table 1 Comparison of actual power generation efficiency and temperature rise data in the outdoor environment

[0062]

[0063]

[0064] According to the comparison results in Table 1, it can be seen that the coating solution prepared in the embodiments of the present application is applied to the light-absorbing surface of photovoltaic glass. The light transmittance is slightly lower than that of the pure SiO2 film, but the light transmittance still remains at 93.5%. Moreover, the attenuation after the damp heat cycle is smaller (0.5% vs. 1.6%), the infrared emissivity is significantly higher (0.92 vs. 0.83), the outdoor temperature rise is reduced by 6°C, and the power generation efficiency is increased by 0.5% (annual average value). This shows that the coating solution prepared in the embodiments of the present application achieves comprehensive performance advantages through rapid dynamic humidity response and high infrared emissivity, balances light transmittance and heat dissipation, has stable performance after the damp heat test, and has better durability than the pure SiO2 film. The photovoltaic glass can be applied in high-temperature and high-humidity areas.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A dynamic humidity-responsive antireflection coating solution, characterized in that, The coating solution consists of SiO2 sol, humidity-responsive cobalt-based complex CETA, dispersant, and absolute ethanol. Among them, when the ambient humidity rises from 30% to 60%, the visible light absorbance of the humidity-responsive cobalt-based complex CETA decreases by ≥50%, the visible light absorbance under high humidity drops to 0.1 - 0.3, the response time is ≤40 seconds, and the infrared emissivity in the 8 - 13μm band increases by ≥5%.

2. The coating solution according to claim 1, wherein By weight, 75 - 76.5 parts of SiO2 sol, 0.5 - 2 parts of humidity-responsive cobalt-based complex CETA, 0.1 - 0.5 parts of dispersant, and the rest is absolute ethanol.

3. The coating solution according to claim 1, characterized in that, The humidity-responsive cobalt-based complex CETA is prepared by the coordination reaction of cobalt chloride hexahydrate with the ligand ethanolamine.

4. The coating solution according to claim 3, wherein The molar ratio of cobalt chloride hexahydrate to ethanolamine is 2:

1.

5. The preparation method of the coating solution according to any one of claims 1-4, characterized in that, It includes the following steps: S01 Prepare humidity-responsive cobalt-based complex CETA Dissolve cobalt chloride hexahydrate in absolute ethanol to form a cobalt chloride / ethanol mixed solution; add ethanolamine for coordination reaction to generate a cobalt-based complex with humidity-responsive characteristics; obtain the dehydrated cobalt-based complex CETA powder through drying treatment. S02 Pretreatment Grind the CETA powder prepared in step S01 to submicron level, D50 ≤ 500nm; mix SiO2 sol and absolute ethanol and stir magnetically for 30 min to form a homogeneous solution. S03 Dispersion Add the CETA powder pretreated in step S02 and the dispersant to the SiO2 sol, stir at low speed for a period of time and then perform ultrasonic treatment, control the temperature below 25°C, and continue to stir magnetically at high speed to obtain a homogeneous dynamic humidity-responsive antireflection coating solution for photovoltaic glass.

6. The application of the coating solution according to any one of claims 1-4, characterized in that, The coating solution is sprayed on the light-absorbing surface of the photovoltaic glass, and the photovoltaic glass is used in high-temperature and high-humidity environment areas.

Images