High-hardness omniphobic self-cleaning antireflection coating, preparation method and application thereof

Abstract

The application discloses a high-hardness dual-repellent self-cleaning antireflection coating suitable for photovoltaic cells and belongs to the field of new materials.The high-hardness dual-repellent self-cleaning antireflection coating comprises a low-refractive-index hollow nanoparticle phase and a low-refractive-index block copolymer phase; the nanoparticle layer and the polymer filler are reasonably designed and combined to obtain the antireflection coating with high surface hardness and excellent dual-repellent self-cleaning performance.The coating can improve the light transmittance of the surface glass of the photovoltaic panel, is hydrophobic and oleophobic, keeps the surface clean, and improves the power generation level; meanwhile, the coating can withstand external mechanical stress damage, prolongs the service life, and reduces the cost waste caused by manual maintenance and cleaning.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new materials, and particularly relates to a high-hardness dual-repellent self-cleaning anti-reflection coating, a preparation method thereof and application thereof. BACKGROUND

[0002] The photovoltaic industry, as a representative of emerging green energy, has been widely developed in recent years. As the main light energy intake interface of the generator set, the light transmittance of the photovoltaic panel directly affects the power generation efficiency of the set. This drives the provision of effective strategies to solve the problem of the decrease of solar energy utilization efficiency caused by the low transmittance due to the surface contamination of the photovoltaic panel and the reflection of light. On the one hand, the attachment of contaminants on the surface of the photovoltaic panel will cause the decrease of light intake, such as the attachment of dust, bird droppings, pollen and rainwater, which will cause contamination on the surface of the photovoltaic panel. On the other hand, the light will be refracted and scattered on the surface of the photovoltaic panel, which will weaken the actual absorption of light energy by the photovoltaic assembly, and also will cause the decrease of power generation.

[0003] CN202310689178.0 discloses a kind of anti-reflection hydrophilic coating for photovoltaic panel and preparation method thereof, by mixing and aging treatment of silica nanoparticle suspension, titanium dioxide composite sol, non-ionic water-soluble polymer, precursor sol is prepared, after the surface of photovoltaic panel is handled and coupling agent is added, then the photovoltaic panel is alternately immersed into PDDA solution and precursor solution, finally rapid quenching, the coating prepared has super hydrophilicity and the transmittance can reach 99.0% at most.

[0004] CN202310982606.9 discloses an anti-reflection hydrophilic coating for photovoltaic panel and a preparation method thereof, organosilicate and nanometer silicon dioxide are added to hydrochloric acid solution for hydrolysis, after 2-5 hours of reaction, magnesium fluoride acid hydrolysis solution is added, and a mixed sol material of nanometer silicon dioxide and magnesium fluoride is obtained by hydrolysis. A mixed alcohol solution and a nanometer titanium dioxide sol are added to the mixed sol material to obtain a nanometer silicon-titanium compound complex magnesium fluoride sol. Finally, the substrate is sequentially placed in acetone and deionized water for ultrasonic cleaning and drying. Finally, the prepared nanometer silicon-titanium compound complex magnesium fluoride sol is coated on the substrate, and then dried after standing to obtain a self-cleaning nanometer coating.

[0005] However, the photovoltaic surface coatings reported so far have only achieved one of the properties of self-cleaning or increased transmittance, and their mechanical durability is still lacking discussion. Therefore, it is still a challenge to prepare a coating that can simultaneously have the properties of dual-repellent surface self-cleaning and anti-reflection and also has excellent resistance to external physical damage. SUMMARY

[0006] This section is intended to introduce some aspects of one or more embodiments of the present application, which are described below. This section is not intended to limit the scope or content of the application in any way. The concepts described herein can apply equally to any embodiment of the application.

[0007] The present application has been made in view of the above and / or problems in the prior art.

[0008] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and to provide a high-hardness dual-repellent self-cleaning anti-reflection coating.

[0009] To solve the above technical problems, the present application provides the following technical solutions: the high-hardness dual-repellent self-cleaning anti-reflection coating comprises,

[0010] Small-aperture hollow silica nanoparticle bottom layer;

[0011] Large-aperture hollow silica nanoparticle top layer;

[0012] And a low-refractive-index fluorosilicon multi-block hardening copolymer filled in the interstitial space of the particles;

[0013] The particle size of the small-aperture hollow silica nanoparticle is 40-45 nm, and the particle size of the large-aperture hollow silica nanoparticle is 45-50 nm.

[0014] As a preferred scheme of the high-hardness dual-repellent self-cleaning anti-reflection coating, in mass percentage, the formula of the high-hardness dual-repellent self-cleaning anti-reflection coating comprises,

[0015] The small-aperture hollow silica nanoparticle bottom layer comprises 10-20 wt% of cetyltrimethylammonium bromide, 5-10 wt% of 30 nm particle size 5% monodisperse nanometer polystyrene ball-ethanol solvent emulsion, and 10-20 wt% of vinyltrimethoxysilane;

[0016] The large-aperture hollow silica nanoparticle top layer comprises 10-20 wt% of 45 nm particle size 5% monodisperse nanometer polystyrene ball-ethanol solvent emulsion, and 5-10 wt% of tetraethyl silicate;

[0017] The low-refractive-index fluorosilicon multi-block hardening copolymer comprises 10-20 wt% of perfluoro-octyl ethyl acrylate, 1-6 wt% of methacryloyloxypropyltrimethoxysilane, 5-15 wt% of methyl methacrylate, 5-15 wt% of methacryloyloxy-cage polysilsesquioxane, and 0.01-1 wt% of azobisisobutyronitrile.

[0018] Still another object of the present application is to overcome the deficiencies in the prior art and provide a preparation method of a high-hardness dual-repellent self-cleaning anti-reflection coating.

[0019] To solve the above technical problems, the present application provides the following technical solutions: comprising,

[0020] Cetyl trimethylammonium bromide is dissolved in ethanol, and stirred uniformly after adjusting pH; then monodisperse nano polystyrene ball emulsion with a particle size of 30nm is added, mixed uniformly, and vinyl trimethoxysilane is added dropwise for reaction to prepare bottom layer small-pore diameter hollow silica nanoparticle suspension, recorded as suspension A;

[0021] Ethanol is added after adjusting pH, and monodisperse nano polystyrene ball emulsion with a particle size of 45nm is added, mixed uniformly, and tetraethyl orthosilicate is added successively for reaction to prepare top layer large-pore diameter hollow silica nanoparticle suspension, recorded as suspension B;

[0022] Perfluorooctyl ethyl acrylate, methacryloyloxypropyl trimethoxysilane, methyl methacrylate and methacryloyloxy-cage polysilsesquioxane are dissolved in tetrahydrofuran, azobisisobutyronitrile is added, and nitrogen is filled to discharge air, and the reaction container is sealed for reaction at 25-45 DEG C for 1-3h to prepare low-refractive fluorosilicon multi-block hardening copolymer solution, recorded as solution C;

[0023] Suspension A and suspension B are coated on the surface of cleaned glass substrate for photovoltaic panel in turn by dip-coating and pulling, dried at 70-90 DEG C for 1h, and calcined at 500-600 DEG C for 1-3h to perform pretreatment of the photovoltaic panel and coating of the hollow silica nanoparticle suspension; solution C is coated by spin coating, and the photovoltaic panel is coated with low-refractive polymer after drying at 70-90 DEG C for 3-5h for curing treatment.

[0024] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection coating, the pH is adjusted to 10-11 by slowly adding 28%-30% ammonia water.

[0025] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection coating, the tetraethyl orthosilicate is added successively, comprising,

[0026] The tetraethyl orthosilicate is divided into 5 parts, and each part is added dropwise into the reaction solution at intervals of 5min, 10min, 30min, 1h and 2h;

[0027] The total reaction time of the tetraethyl orthosilicate in the reaction system is 10h.

[0028] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating, in the scheme, the dip-coating and pulling includes,

[0029] The suspension to be coated is placed in a suitable container to ensure that the liquid level can submerge the glass substrate placed vertically; the dip-coating and pulling process is completed by a dip-coater, first, the glass substrate is fixed on the fixing clamp of the dip-coater, and the height is manually adjusted to be slightly higher than the surface of the suspension to be coated; then, the descending speed is set to 50-650 μm / s, the dip-coating time is set to 5-30 s, and the pulling speed is set to 50-650 μm / s.

[0030] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating, in the scheme, the mass ratio of the 30 nm monodisperse nano polystyrene ball emulsion to the vinyl trimethoxysilane is 1:1.125-4.5.

[0031] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating, in the scheme, the mass ratio of the 45 nm monodisperse nano polystyrene ball emulsion to the tetraethyl silicate is 1-4:2-1.

[0032] As a preferred scheme of the preparation method of the high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating, in the scheme, the mass ratio of the perfluorooctyl ethyl acrylate, the methacryloyloxypropyl trimethoxysilane, the methyl methacrylate and the methacryloyloxy-caged polysilsesquioxane is 2-4:1-3:2-4:1-3; the addition amount of the azobisisobutyronitrile is 0.2-1 wt% of the total mass of the perfluorooctyl ethyl acrylate, the methacryloyloxypropyl trimethoxysilane, the methyl methacrylate and the methacryloyloxy-caged polysilsesquioxane monomers.

[0033] Another object of the application is to provide an application of the high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating on the surface of a photovoltaic cell to overcome the defects in the prior art.

[0034] The application has the following beneficial effects:

[0035] 1. The high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating can reduce the loss of the incident light caused by reflection and refraction, increase the light energy that can reach the core components of the photovoltaic cell, and thus improve the power generation capacity.

[0036] 2. The high-hardness dual-repellent self-cleaning anti-reflection and anti-reflective coating has excellent hydrophobic and oleophobic properties and surface self-cleaning performance, can keep the surface of the photovoltaic panel clean for a long time, reduce the negative influence of the pollutants on the light absorption of the components, and maintain a high power generation capacity level.

[0037] 3. The high-hardness dual-repellent self-cleaning anti-reflection coating has high surface hardness and good mechanical durability, and the coating can maintain inherent performance after being subjected to external stress and wear damage for a certain period of time, thereby prolonging service life. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0039] Figure 1 The schematic diagram of the high-hardness dual-repellent self-cleaning anti-reflection coating suitable for photovoltaic cell panel prepared in Example 1 of the present application.

[0040] Figure 2 The particle size distribution curves of two different hollow pore diameter nanoparticles.

[0041] Figure 3 The comparison curve of transmittance in the visible region of the coating-glass and the original glass prepared in Example 1 of the present application.

[0042] Figure 4 The Vickers hardness measurement of the coating surface prepared in Example 1 of the present application.

[0043] Figure 5 The anti-wetting performance of the coating prepared in Example 1 of the present application.

[0044] Figure 6 The curve of the contact angle and sliding angle of water on the surface of the coating prepared in Example 1 of the present application with the change of abrasion test.

[0045] Figure 7 The power generation test of the photovoltaic panel coated with the coating prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail in combination with the description.

[0047] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0048] Second, as used in the specification and claims, the phrase "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the application. The appearances of the phrase "in one embodiment" or "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

[0049] The raw materials used in the present application are all commercially available.

[0050] The coating prepared in the embodiments of the present application is tested for performance as follows:

[0051] Vickers hardness: The hardness of the coating surface was measured using a FALCON 507 Vickers microhardness tester. Vickers hardness is a measure of the hardness value calculated from the pressure that the unit surface area of the indentation can withstand. It is a square indentation pressed onto the test surface of the sample by a diamond pyramid with a 136° angle under a certain pressure. The average length of the two diagonal lines of the indentation is measured by a microscope set on the Vickers hardness tester, and the Vickers hardness value is obtained from the corresponding table. Vickers hardness is commonly represented by the symbol HV, where the value before HV is the Vickers hardness value and the value after HV is the load weight value during testing.

[0052] Visible light transmittance: The transmittance of visible light of the sample (coating-glass and original glass) was tested using a Shimadzu UV 3600 ultraviolet-visible spectrophotometer. The size of the test sample was 7.5 cm x 2.5 cm, and a glass slide of the same size was selected as the control sample during testing. The transmittance of air was set as the baseline for testing. The wavelength range for testing was 400 nm to 800 nm.

[0053] Contact angle: The contact angle of water droplets / oil droplets on the coating surface was measured using a KRüSS DSA25S optical contact angle analysis system. For the measurement of the contact angle in a non-moving state, water droplets / oil droplets (~ 5 μL) were first added to the sample surface by a syringe controlled by a motor. When the droplets were stable, a side view image was taken by a camera, and the static contact angle value of the water droplets / oil droplets on the coating surface was calculated by fitting using software.

[0054] Sliding angle: The sliding angle of water droplets / oil droplets on the coating surface was measured using a KRüSS DSA25S optical contact angle analysis system. For the sliding angle measurement, a motor-controlled rotatable test platform was used to tilt the sample, and the rotation angle of the platform was displayed in real time on a computer connected to the motor. The initial tilt angle of the platform at the start of the test was kept at 0°, and after a water droplet / oil droplet (~5 μL) was added to the coating surface by a syringe, the motor was controlled to rotate the platform. The rotation was stopped at the moment when the droplet began to roll on the surface, and the rotation angle displayed on the computer was recorded as the rolling angle. Each sample was measured at three different locations to reduce data errors.

[0055] Power generation of coated photovoltaic panels: The total power generation was measured cumulatively using a WT5000 power analyzer, and the photovoltaic panel used in the photovoltaic power generation performance test was a commercial silicon-based photovoltaic power generation panel, and the test lasted for one month. During the test, the voltage input port was connected in parallel with the photovoltaic panel, and the current port was connected in series with the output port of the photovoltaic panel.

[0056] DI: deionized water; EtOH: anhydrous ethanol; THF: tetrahydrofuran; CTAB: cetyltrimethylammonium bromide; TEOS: tetraethyl orthosilicate; PSNS: monodisperse nanometer polystyrene ball emulsion (ethanol solvent, 5%, particle size 30, 45 nm); PFEA: perfluorooctyl ethyl acrylate; KH-570: methacryloxypropyltrimethoxysilane; KH-171: vinyltrimethoxysilane; MMA: methyl methacrylate; M-POSS: methacryloxy-caged polyhedral oligomeric silsesquioxane; AIBN: azobisisobutyronitrile.

[0057] Example 1

[0058] The present embodiment provides a method for preparing a high-hardness dual-repellent self-cleaning antireflection coating, specifically comprising:

[0059] (1) 0.45 g of CTAB was dissolved in 55 mL of EtOH, and then 28%-30% ammonia water was slowly added to adjust the pH to 10-11, and the solution was continuously stirred at 600 rpm at room temperature for 30 min. Then 0.2 g of monodisperse nanometer polystyrene ball emulsion with a particle size of 30 nm was added to the above solution, and after mixing and stirring for 10 min, 0.45 g of KH-171 was added dropwise, and then the stirring was maintained, and a uniform suspension was obtained after 10 h of reaction, which was recorded as suspension A.

[0060] (2) Measure 55 mL of EtOH in a round-bottom flask, then slowly add 28%~30% ammonia water to adjust the pH to 10~11, and stir at 600 rpm at room temperature for 30 min. Then weigh 0.45 g of monodisperse nano polystyrene ball emulsion with a particle size of 45 nm into the above solution, mix and stir for 10 min to obtain a uniform emulsion. Then divide 0.225 g of TEOS into 5 equal parts, and add "one part" of TEOS to the above emulsion every 10 min, for a total of 5 times, for a total of 50 min, then keep stirring, and after 10 h of reaction, a uniform suspension is obtained, which is recorded as suspension B.

[0061] (3) Weigh PFEA, KH-570, MMA and M-POSS (mass percentage: 40wt%, 10wt%, 30wt%, 20wt%) into THF, stir at room temperature for 10 min, then add initiator AIBN (0.5wt% of the total mass of monomers), and then fill nitrogen to expel air. After the reaction container is sealed, it is reacted at 35°C for 2 h to obtain a polymer solution, which is recorded as solution C.

[0062] (4) First, the glass substrate for photovoltaic panels is washed with EtOH and DI alternately for 2 times, and then dried. Then the suspension A is coated on the surface of the glass substrate by dip-coating and pulling, and after drying treatment in a 80°C air drying oven for 1 h, the suspension B is coated on the surface of the glass substrate by dip-coating and pulling, and after drying treatment in a 80°C air drying oven for 1 h, the PSNS and CTAB are calcined at 550°C for 2 h.

[0063] (5) The solution C is coated on the glass substrate prepared in the previous step by spin coating.

[0064] (6) The glass prepared in the previous step is placed in an air drying oven and dried at 80°C for 4 h, so that a high-hardness dual-repellent self-cleaning antireflection coating layer is obtained on the surface of the substrate.

[0065] Figure 1 The schematic diagram of the high-hardness dual-repellent self-cleaning antireflection coating layer suitable for photovoltaic cell panels prepared in Example 1 is shown in the figure. Small-aperture hollow nanoparticles with a relatively high reflection coefficient are used as the bottom layer, and large-aperture hollow nanoparticles with a relatively low reflection coefficient are used as the top layer, forming an antireflection layer with a reflection gradient on the surface of the glass substrate. The filling of the inter-particle pores by the low-reflection coefficient fluorine-containing multi-block copolymer improves the anti-wetting performance of the coating surface, and also enhances the mechanical stability between the particles and the substrate material.

[0066] Figure 2The particle size distribution curves of two different hollow aperture nanoparticles can be seen, the particle size of small aperture nanoparticles is mainly distributed in the range of 40-45 nm, and the particle size of large aperture nanoparticles is mainly distributed in the range of 45-50 nm, which shows that the particle size of monodisperse polystyrene nanospheres directly affects the inner diameter of the hollow nanoparticles, and KH-171 is more likely to form a thicker outer wall than TEOS.

[0067] And the test shows that Figure 3 The average transmittance of the high-hardness dual-repellent self-cleaning antireflection and anti-reflective coating prepared by the application in the visible light region reaches 95.3%, which is about 3% higher than that of the original substrate, indicating that it has the effect of antireflection and anti-reflective; the Vickers hardness of the coating surface reaches 414.03HV0.02 (as shown in Figure 4 ), which shows that the surface hardness is high; the contact angle of water droplets on the coating surface is 104.7°, and the sliding angle is 13.8°, the contact angle of oil on the surface is 16.3°, and the sliding angle is 1.12° (as shown in Figure 5 ), which shows that the coating has excellent repellent properties for oil and water; the coating can still maintain the integrity of performance and structure after Taber abrasion (as shown in Figure 6 ); after comparing the stage power generation of the coating-photovoltaic panel and the untreated-photovoltaic panel, it is also confirmed that the coating has a power generation improvement effect on the photovoltaic assembly (as shown in Figure 7 ).

[0068] Example 2

[0069] The difference between this embodiment and example 1 is that the mass ratio of 30 nm monodisperse nanometer polystyrene ball emulsion to KH-171 in the preparation process of small pore nanoparticle suspension is 1:1.125 (0.4 g of 30 nm monodisperse nanometer polystyrene ball emulsion and 0.45 g of KH-171 are weighed), and the rest of the preparation process is the same as example 1, and the coating is prepared.

[0070] Example 3

[0071] The difference between this embodiment and example 1 is that the mass ratio of 30 nm monodisperse nanometer polystyrene ball emulsion to KH-171 in the preparation process of small pore nanoparticle suspension is 1:4.5 (0.2 g of 30 nm monodisperse nanometer polystyrene ball emulsion and 0.9 g of KH-171 are weighed), and the rest of the preparation process is the same as example 1, and the coating is prepared.

[0072] The performance test results of the materials prepared in the above examples are shown in Table 1 compared with example 1.

[0073] Table 1

[0074]

[0075] The slash in the table indicates that the data is not tested.

[0076] The above examples are mainly the exploration of the process condition variables of the preparation of the bottom layer small-pore hollow nanoparticles, mainly reflected in the influence on the visible light transmittance. As can be seen from the table, different addition amounts of the monodisperse nanometer polystyrene ball emulsion and KH-171 will affect the hollow pore diameter and the ball wall thickness of the prepared hollow nanoparticles. When only the mass of the monodisperse nanometer polystyrene ball emulsion is increased, the hollow pore diameter of the prepared hollow nanoparticles is increased, and since the addition amount and the addition method of KH-171 are not changed, the ball wall thickness changes little, and the reflectivity of the hollow nanoparticles is reduced compared with that in example 1, which will cause the difference between the reflectivity of the bottom layer small-pore hollow nanoparticle layer and the glass substrate to increase, causing the interface reflection to be enhanced compared with example 1, and the light transmittance to be reduced; when only the addition amount of KH-171 is increased, the ball wall thickness of the prepared hollow nanoparticles is increased, and since the mass and the addition method of the monodisperse nanometer polystyrene ball emulsion are not changed, the inner diameter of the hollow nanoparticles changes little, and the reflectivity of the hollow nanoparticles is increased compared with that in example 1, which will cause the difference between the reflectivity of the bottom layer small-pore hollow nanoparticle layer and the top layer large-pore hollow nanoparticle layer to increase, causing the interface reflection to be enhanced compared with example 1, and the light transmittance to be reduced.

[0077] According to the test, the average transmittance of the coating prepared in example 2 and example 3 in the visible light region is about 94.7% and 93.6% respectively, which is considered to be caused by the change of the reflectivity gradient caused by the change of the physical properties of the small-pore hollow nanoparticles, but the coating still has the effect of increasing the transmittance and reducing the reflection.

[0078] According to the above table results, the best technical effect can be obtained when the mass ratio of 30 nm monodisperse nanometer polystyrene ball emulsion to KH-171 is 1:2.25 in the preparation process of the small-pore nanoparticle suspension in the application.

[0079] Example 4

[0080] The difference between this example and example 1 is that the mass ratio of 45 nm monodisperse nanometer polystyrene ball emulsion to TEOS is adjusted to 1:2 (0.45 g of 45 nm monodisperse nanometer polystyrene ball emulsion and 0.9 g of TEOS are weighed) in the preparation process of the large-pore nanoparticle suspension, and the rest of the preparation process is the same as that of example 1, and the coating is prepared.

[0081] Example 5

[0082] The difference between the present embodiment and embodiment 1 is that the mass ratio of 45 nm monodisperse nanometer polystyrene ball emulsion to TEOS in the preparation process of the macroporous nanoparticle suspension is 4:1 (0.9 g of 45 nm monodisperse nanometer polystyrene ball emulsion and 0.225 g of TEOS are weighed), and the rest of the preparation process is the same as that of embodiment 1, and the coating is prepared.

[0083] The performance test of the material prepared in the above embodiment is compared with that of embodiment 1, and the results are shown in Table 2.

[0084] Table 2

[0085]

[0086]

[0087] The above embodiment mainly explores the process condition variables of the top layer macroporous hollow nanoparticle preparation, mainly reflected in the influence on the visible light transmittance. As shown in the above table, the addition amount of 45 nm monodisperse nanometer polystyrene ball emulsion and TEOS will affect the hollow pore size and the thickness of the ball wall of the prepared hollow nanoparticle. In embodiment 4, when only the mass of TEOS is increased, the hollow pore size of the prepared hollow nanoparticle changes little, the thickness of the ball wall increases, the reflectivity of the macroporous hollow nanoparticle increases compared with that in embodiment 1, the difference in reflectivity between the top layer macroporous hollow nanoparticle layer and air increases, the interface reflection is relatively enhanced compared with embodiment 1, and the light transmittance decreases. The test shows that the average transmittance of the coating prepared in embodiment 4 in the visible light region is about 93.5%; when only the mass of 45 nm monodisperse nanometer polystyrene ball is increased, the hollow pore size of the prepared hollow nanoparticle becomes larger, the thickness of the ball wall changes little, the reflectivity of the macroporous hollow nanoparticle decreases compared with that in embodiment 1, the difference in reflectivity between the top layer macroporous hollow nanoparticle layer and the bottom layer microporous hollow nanoparticle layer increases, the interface reflection is relatively enhanced compared with embodiment 1, and the light transmittance decreases. The test shows that the average transmittance of the coating prepared in embodiment 4 in the visible light region is about 94.1%.

[0088] According to the results in the above table, the mass ratio of 45 nm monodisperse nanometer polystyrene ball emulsion to TEOS in the preparation process of the microporous nanoparticle suspension in the present application is 2:1, which can obtain the best technical effect.

[0089] Embodiment 6

[0090] The difference between this embodiment and embodiment 1 is that the mass percentages of PFEA, KH-570, MMA and M-POSS in the preparation process of the fluorine-containing block copolymer are 30wt%, 13wt%, 33wt% and 24wt% respectively, and the rest of the preparation process is the same as that of embodiment 1, and the coating is prepared.

[0091] Example 7

[0092] The difference between this embodiment and embodiment 1 is that the mass percentages of PFEA, KH-570, MMA and M-POSS in the preparation process of the fluorine-containing block copolymer are 40wt%, 10wt%, 40wt% and 10wt% respectively, and the rest of the preparation process is the same as that of embodiment 1, and the coating is prepared.

[0093] The performance test of the material prepared in the above embodiment is compared with that of embodiment 1, and the results are shown in Table 3.

[0094] Table 3

[0095]

[0096] The above embodiments mainly explore the process condition variables of the fluorine-containing multi-block copolymer, mainly reflecting the influence on the surface hardness and anti-wetting performance. As can be seen from the above table, different mass percentages of the four components in the fluorine-containing block copolymer will affect the omniphobic performance and mechanical durability of the coating. The mass percentage of PFEA in embodiment 6 is reduced. After testing, the coating prepared in embodiment 6 has a certain degree of decline in hydrophobic and oleophobic performance, such as the contact angle of water on the surface is reduced to 98.6°, and the sliding angle is 14.7°; the contact angle of oil on the surface is 15.8°, and the sliding angle is 2.1°. However, the coating still has omniphobic self-cleaning performance.

[0097] The coating prepared in embodiment 7 has a certain degree of decline in surface hardness, and the Vickers hardness of the coating surface is about 362.14HV0.02. However, the coating still has high surface hardness and can resist a certain degree of external stress damage.

[0098] In summary, the preferred mass ratio of PFEA, KH-570, MMA and M-POSS is 4:1:3:2.

[0099] Comparative example 1

[0100] Original glass.

[0101] Figure 3The contrast curve of the transmittance of the coated glass and the original glass in the visible light region for the example 1 of the present application is prepared, and it can be seen that the average transmittance of the original glass in the visible light region is 91.7%, while the average transmittance of the example 1 in the visible light region is 95.3%, which shows that the coating has the effect of antireflection and transmittance enhancement.

[0102] Comparative example 2

[0103] The difference between the present example and the example 1 is that the dip-coating method in the preparation step (4) in the comparative example is replaced by the spray gun spraying method, and the rest of the preparation process is the same as that of the example 1, and the coating is prepared.

[0104] The performance test is carried out on the material prepared in the above comparative example, and the comparison results of the example 1 are shown in table 4.

[0105] Table 4

[0106]

[0107] The comparison of the example 1 and the comparative examples 1 and 2 is mainly to compare the original glass and to explore the coating process method, which is mainly reflected in the influence on the transmittance in the visible light region and the anti-wetting performance. As can be seen from the above table, the coating prepared by the present application has obvious effect of antireflection and transmittance enhancement compared with the original glass. The thickness of the coating prepared in the comparative example 2 is obviously increased compared with the example 1, and the surface roughness is also obviously increased, which leads to the sharp rise of the reflectivity of the coating, and the light transmittance in the visible light region is only 76.1%.

[0108] The high-surface-hardness dual-repellent self-cleaning antireflection and transmittance-enhancing coating provided by the present application comprises a low-refractive-index hollow nanoparticle phase and a low-refractive-index block copolymer phase. By reasonably designing and combining the nanoparticle layer and the polymer filler, an antireflection and transmittance-enhancing coating with high surface hardness and excellent dual-repellent self-cleaning performance is obtained. The coating can improve the light transmittance of the surface glass of the photovoltaic panel, is hydrophobic and oleophobic, keeps the surface clean, and improves the power generation level. At the same time, it can withstand external mechanical stress damage, prolong the service life, and reduce the cost waste caused by artificial maintenance and cleaning.

[0109] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A high-hardness, dual-repellent, self-cleaning, anti-reflective, and anti-reflective coating, characterized in that: The high-hardness, dual-repellent, self-cleaning, anti-reflective, and refractive coating includes, Small-pore hollow silica nanoparticle bottom layer; Top layer of large-pore hollow silica nanoparticles; And low-refractive-index fluorosilicone multiblock hardening copolymers filling the interparticle spaces; The small-pore hollow silica nanoparticles have a particle size of 40-45 nm, and the large-pore hollow silica nanoparticles have a particle size of 45-50 nm. The preparation method of the high-hardness, dual-repellent, self-cleaning, anti-reflective, and high-hardness dual-repellent self-cleaning coating includes, Hexadecyltrimethylammonium bromide was dissolved in ethanol, and the pH was adjusted and stirred until homogeneous. Then, monodisperse polystyrene nanospheres with a particle size of 30 nm were added and mixed. Vinyltrimethoxysilane was added dropwise to react and a suspension of hollow silica nanoparticles with small bottom pores was prepared, denoted as suspension A. After adjusting the pH with ethanol, monodisperse polystyrene nanospheres with a particle size of 45 nm were added and mixed evenly. Then, tetraethyl silicate was added sequentially to react and prepare a suspension of hollow silica nanoparticles with a top layer of large pores, denoted as suspension B. The suspension A comprises 10-20 wt% hexadecyltrimethylammonium bromide, 5-10 wt% monodisperse polystyrene nanospheres with a particle size of 30 nm and a particle size of 5%, and 10-20 wt% vinyltrimethoxysilane; The suspension B comprises 10-20 wt% monodisperse polystyrene nanosphere emulsion with a particle size of 5% at 45 nm and 5-10 wt% tetraethyl silicate; Perfluorooctyl ethyl acrylate, methacryloxypropyltrimethoxysilane, methyl methacrylate, and methacryloxy-cage polysilsesquioxane were dissolved in tetrahydrofuran. After adding azobisisobutyronitrile, nitrogen gas was introduced to purge the air. The reaction vessel was sealed and reacted at 25-45°C for 1-3 hours to prepare a low-refractive-index fluorosilicone multiblock hardening copolymer solution, denoted as solution C. The solution C comprises 10-20 wt% perfluorooctyl ethyl acrylate, 1-6 wt% methacryloxypropyltrimethoxysilane, 5-15 wt% methyl methacrylate, 5-15 wt% methacryloxy-cage polysilsesquioxane, and 0.01-1 wt% azobisisobutyronitrile. Suspension A and suspension B were successively coated onto the cleaned glass substrate for photovoltaic panels using dip-coating and dip-coating methods. After drying at 70-90℃ for 1 hour, the substrate was calcined at 500-600℃ for 1-3 hours to pre-treat the photovoltaic panel and coat it with the suspension of hollow silica nanoparticles. Solution C was then applied by spin coating to complete the low-refractive-index polymer coating on the photovoltaic panel. After drying at 70-90℃ for 3-5 hours, the substrate was cured.

2. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and anti-reflective coating as described in claim 1, characterized in that: The pH is adjusted to 10-11 by slowly adding 28%-30% ammonia.

3. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and anti-reflective coating as described in claim 1, characterized in that: The sequential addition of tetraethyl silicate includes, Tetraethyl silicate was divided into 5 equal parts, and each part of tetraethyl silicate was added dropwise to the reaction solution at intervals of 5 min, 10 min, 30 min, 1 h, and 2 h. The total reaction time of the tetraethyl silicate in the reaction system is 10 hours.

4. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and anti-reflective coating as described in claim 1, characterized in that: The dip-coating-lifting process includes, The suspension to be coated is placed in a suitable container, ensuring that the liquid level completely submerges the vertically placed glass substrate. The dip-coating-lifting process is completed by the dip-coating machine. First, the glass substrate is fixed on the fixed clamp of the dip-coating machine, and the height is manually adjusted so that the lower edge of the glass substrate is slightly higher than the surface of the suspension to be coated. Then, the descent speed is set to 50~650 μm / s, the dip-coating time is 5~30s, and the lift-up speed is 50~650 μm / s.

5. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and high-hardness coating as described in claim 1, characterized in that: The mass ratio of the 30 nm monodisperse polystyrene nanosphere emulsion to vinyltrimethoxysilane is 1:2.

25.

6. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and anti-reflective coating as described in claim 1, characterized in that: The mass ratio of the 45 nm monodisperse polystyrene nanosphere emulsion to tetraethyl silicate is 2:

1.

7. The high-hardness, dual-repellent, self-cleaning, anti-reflective, and high-hardness coating as described in claim 1, characterized in that: The mass ratio of perfluorooctyl ethyl acrylate, methacryloxypropyltrimethoxysilane, methyl methacrylate, and methacryloxy-cage polysilsesquioxane is 4:1:3:2; the amount of azobisisobutyronitrile added is 0.5 wt% of the total mass of the monomers perfluorooctyl ethyl acrylate, methacryloxypropyltrimethoxysilane, methyl methacrylate, and methacryloxy-cage polysilsesquioxane.

8. The application of the high-hardness, dual-hydrophobic, self-cleaning, antireflective, and anti-reflective coating as described in claim 1 on the surface of photovoltaic cells.

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