Coating as well as preparation method and application thereof

Abstract

The invention discloses a coating as well as a preparation method and application thereof. The coating comprises the following raw materials: potassium silicate; ethyl orthosilicate; a nanometer titanium dioxide sol; rare earth is doped with nano titanium dioxide; compounding zinc oxide nanoparticles; nano silicon dioxide sol; a fluorosilane coupling agent; a fluorocarbon surfactant; a conductive carbon nanotube; nano aluminum oxide sol; an organic silicon modified acrylate emulsion; a boron nitride nanosheet; hollow glass beads; a shape memory polymer; the invention discloses a self-repairing nanofiber. After a coating is formed by using the coating, the coating has the characteristics of high light transmittance, good self-cleaning effect, high hardness, good adhesive force and excellent weather resistance, and can be applied to a photovoltaic module to replace an existing photovoltaic module coating product.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a coating, a preparation method thereof, and an application thereof. Background Art

[0002] With the increasing popularity of photovoltaic power generation technology, the long-term stable and efficient operation of photovoltaic modules faces many difficulties. Currently, a coating is often applied to the surface of existing photovoltaic modules to form a coating film, but many drawbacks have emerged in the current coating film products in the existing technology:

[0003] Poor self-cleaning efficiency: Most of them can only achieve basic hydrophobic and oleophobic effects, and cannot decompose the stains attached to the surface through photocatalysis. After long-term outdoor use, a large amount of pollutants such as dust and oil accumulate, greatly hindering the effective absorption of sunlight by photovoltaic modules and causing a sharp decline in power generation efficiency.

[0004] Unsatisfactory optical properties: Traditional coatings lack the functions of increasing light transmittance and reducing reflection. When sunlight irradiates the photovoltaic surface, the reflection loss is significant, and the light energy utilization rate is greatly reduced; and it is difficult to properly handle the destructive ultraviolet light. Long-term ultraviolet light irradiation not only damages photovoltaic materials but also accelerates the aging process of the modules.

[0005] Shortcomings in electrical properties: It does not have antistatic performance. The static electricity accumulated on the surface of photovoltaic modules is easy to adsorb dust, further reducing the power generation efficiency. At the same time, there are also certain safety risks.

[0006] Fragile mechanical properties: The hardness is insufficient. In harsh environments such as strong winds and sandstorms and rainwashing, the coating film is extremely easy to wear and fail, and cannot build a long-term protection barrier for the photovoltaic surface; once damaged, it cannot self-repair, greatly shortening the service life of photovoltaic modules.

[0007] Lagging thermal properties: The thermal conductivity is poor. The heat generated when photovoltaic modules work is difficult to dissipate quickly, causing local high-temperature phenomena, seriously affecting the battery conversion efficiency; and it lacks radiative cooling ability and cannot assist in cooling in high-temperature and hot environments, unable to ensure the normal operation of the modules. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a coating, a preparation method thereof, and an application thereof. After forming a coating with this coating, it has the characteristics of high light transmittance, good self-cleaning effect, strong hardness, good adhesion, and excellent weather resistance, and can be applied to photovoltaic modules to replace the existing coating film products of photovoltaic modules.

[0009] The above technical objectives of the present invention are achieved through the following technical solutions:

[0010] A coating material, comprising the following raw materials: potassium silicate; tetraethyl orthosilicate; nano-titanium dioxide sol; rare earth-doped nano-titanium dioxide; composite zinc oxide nanoparticles; nano-silica sol; fluorosilane coupling agent; fluorocarbon surfactant; conductive carbon nanotubes; nano-aluminum oxide sol; organosilicon-modified acrylate emulsion; boron nitride nanosheets; hollow glass microspheres; shape memory polymer; self-healing nanofibers.

[0011] In some embodiments of the present invention, the coating material comprises the following raw materials in parts by weight: potassium silicate: 10 - 35 parts; tetraethyl orthosilicate: 10 - 30 parts; nano-titanium dioxide sol: 5 - 15 parts; rare earth-doped nano-titanium dioxide: 5 - 10 parts; composite zinc oxide nanoparticles: 10 - 20 parts; nano-silica sol: 5 - 15 parts; fluorosilane coupling agent: 1 - 5 parts; fluorocarbon surfactant: 1 - 5 parts; conductive carbon nanotubes: 0.1 - 1 part; nano-aluminum oxide sol: 1 - 10 parts; organosilicon-modified acrylate emulsion: 1 - 10 parts; boron nitride nanosheets: 1 - 5 parts; hollow glass microspheres: 1 - 5 parts; shape memory polymer: 1 - 5 parts; self-healing nanofibers: 1 - 5 parts.

[0012] In some embodiments of the present invention, the potassium silicate selected is potassium silicate with an ultra-high purity refinement and a modulus of 3.333. Through membrane separation and crystallization technology, its impurity content is reduced to the ppm level. Its highly regular lattice structure can achieve tight chemical bonding with other components, providing excellent adhesion, hardness, and long-term chemical stability for the coating, ensuring that the coating performance does not degrade in harsh environments.

[0013] In some embodiments of the present invention, tetraethyl orthosilicate adopts a microfluidic chip combined with supercritical fluid drying technology and introduces microwave plasma assistance to precisely control the hydrolysis and polycondensation reaction processes. In the microfluidic chip, the reactants are mixed at precise flow rates and ratios to form a uniform and stable precursor. Subsequently, in a supercritical carbon dioxide environment, it is excited by microwave plasma to generate a three-dimensional network structure with highly ordered, nano-scale pore diameters and pore walls rich in active sites, significantly enhancing the mechanical strength, anti-permeability ability, and binding force with other components of the coating.

[0014] In some embodiments of the present invention, the nano-titanium dioxide in the nano-titanium dioxide sol is anatase-type titanium dioxide.

[0015] In some embodiments of the present invention, the particle size of the nano-titanium dioxide in the nano-titanium dioxide sol is 10 - 20 nm.

[0016] In some embodiments of the present invention, the particle size of the nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm.

[0017] In some embodiments of the present invention, the rare earth doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of (1-3):(1-3):(1.1-1.5):(0.1-0.3):(0.01-0.05). During the preparation process of the rare earth doped nano-titanium dioxide, the suspension after doping the rare earth elements and nano-titanium dioxide is transferred to a high-pressure reaction kettle and reacted under hydrothermal conditions at 100-180 °C for 3-20 hours, so as to achieve precise doping at the atomic level on the surface of the nano-titanium dioxide, and precisely control the doping depth within 1-3 atomic layers. This precise doping method not only broadens the light absorption range, extending from ultraviolet light to the near-infrared light region, but also significantly enhances the migration rate of photo-generated carriers and the ability to inhibit recombination, greatly improving the photocatalytic performance and the efficiency of light conversion into blue-green light, especially showing excellent performance under weak light and complex lighting conditions.

[0018] In some embodiments of the present invention, the core of the composite zinc oxide nanoparticles is zinc oxide with optimized lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots. Such composite zinc oxide nanoparticles are prepared by a multi-step chemical synthesis method, including steps such as lattice optimization, shell layer deposition and surface modification. Specifically, first, zinc oxide nanoparticles are prepared by a hydrothermal synthesis method and subjected to lattice optimization treatment. Then, a multi-layer composite shell layer is formed on the surface of the zinc oxide particles by hydrothermal synthesis. Finally, functional nanoparticles are loaded on the particle surface through surface modification technology to achieve the desired performance. The specific preparation method is as follows:

[0019] Raw material preparation: Prepare high-purity zinc oxide nanoparticles, titanium dioxide, cadmium sulfide, nano-silver, titanium dioxide quantum dots and carbon nanodots.

[0020] Core preparation: Prepare zinc oxide nanoparticles by a hydrothermal synthesis method and perform lattice optimization treatment.

[0021] Middle shell layer preparation: Disperse the zinc oxide nanoparticles in a solution containing precursors of titanium dioxide and cadmium sulfide, and form a ternary composite shell layer on the surface of the zinc oxide particles by hydrothermal synthesis.

[0022] Outer layer loading: Mix the above composite particles with a nano-silver solution, and load nano-silver satellite particles on the particle surface through a reduction reaction.

[0023] Outermost layer wrapping: Finally, react the composite particles loaded with nano-silver with a mixed solution of titanium dioxide quantum dots and carbon nanodots, and form a corona layer on the outermost layer by chemical deposition method.

[0024] This unique structure not only enhances light absorption, scattering, and catalytic activity, but also optimizes the optical properties in the infrared band by utilizing the synergistic effect of each component, significantly enhancing the radiative cooling effect. Meanwhile, the antibacterial properties of silver nanoparticles and titanium dioxide quantum dots effectively prevent the growth of microorganisms on the coating surface, while carbon dots improve the electron conduction ability of the coating, further enhancing the photocatalytic efficiency.

[0025] In some embodiments of the present invention, the particle size of the composite zinc oxide nanoparticles is 20 - 30 nm.

[0026] In some embodiments of the present invention, the particle size of the composite zinc oxide nanoparticles is 28.9 nm.

[0027] In some embodiments of the present invention, the light transmittance enhancement rate of the nano - silica sol is 2.3% - 2.5%. In the coating of the present invention, nano - silica sol is used. This sol has good dispersibility and stability and is suitable for forming high - performance coatings. This nano - silica sol is prepared by conventional chemical synthesis methods, such as the sol - gel method or precipitation method, ensuring the uniformity of its particle size and distribution. It effectively reduces the light reflection loss and improves the light capture ability of the photovoltaic module, especially showing excellent light transmittance enhancement and anti - reflection performance in a wide spectral range.

[0028] In some embodiments of the present invention, the particle size of the nano - silica in the nano - silica sol is 10 - 15 nm.

[0029] In some embodiments of the present invention, the particle size of the nano - silica in the nano - silica sol is 13.35 nm.

[0030] In some embodiments of the present invention, the fluorine content of the fluorosilane coupling agent is 40 wt% - 50 wt%. In the molecular structure of the fluorosilane coupling agent, cross - linkable active groups, flexible chain segments, and photo - responsive groups are introduced. During the film - forming process of the coating, the active groups chemically react with the inorganic film - forming substances composed of potassium silicate, tetraethyl orthosilicate, and nano - titanium dioxide sol to form strong chemical bonds, enhancing the interfacial bonding force; the flexible chain segments endow the coating with excellent flexibility, enabling it to better adapt to the thermal expansion and contraction of the photovoltaic module at different temperatures; the photo - responsive groups undergo structural changes under light irradiation, further reducing the surface energy, improving the self - cleaning performance, and enhancing the photocatalytic effect to a certain extent.

[0031] In some embodiments of the present invention, the fluorocarbon surfactant is an amphiphilic perfluoropolyether surfactant, including but not limited to perfluorooctylsulfonyl polyoxyethylene ether and perfluoropolyether sulfonate. By introducing various functional groups sensitive to temperature, humidity, light, and electric field through molecular design, under different environmental conditions, the surfactant can automatically adjust the molecular arrangement, maintain a low surface tension (below 14 mN / m) on the coating surface, and achieve an efficient self-cleaning function. At the same time, this intelligent responsiveness also enhances the antistatic performance, can automatically adjust the surface charge density according to environmental changes, and effectively prevent dust adsorption. In addition, under light conditions, the change in the molecular structure of the surfactant can also promote the photocatalytic reaction and synergistically enhance the self-cleaning effect.

[0032] In some embodiments of the present invention, the surface of the conductive carbon nanotubes is coated with a layer of conductive polymer and loaded with nanoscale metal oxide particles and graphene quantum dots. By using a method combining chemical vapor deposition and in-situ polymerization, a layer of conductive polymer (such as polyaniline) is uniformly coated on the surface of the carbon nanotubes, and nanoscale metal oxide (such as manganese dioxide) particles and graphene quantum dots are loaded. This composite structure not only improves the dispersibility of the carbon nanotubes in the coating but also forms a multi-level conductive network, significantly enhancing the antistatic performance. In addition, the metal oxide particles, graphene quantum dots, and carbon nanotubes act synergistically to improve the electromagnetic shielding performance, photocatalytic performance, and the adsorption and degradation ability of organic pollutants of the coating.

[0033] In some embodiments of the present invention, the conductive polymer is polyaniline and the metal oxide particles are manganese dioxide particles.

[0034] In some embodiments of the present invention, the nano-alumina sol is β-nano-alumina sol, and the particle size of the nano-alumina in the nano-alumina sol is 20 - 25 nm. The preparation method of the nano-alumina sol includes the following steps: Sol-gel method: First, prepare the nano-alumina sol by the sol-gel method. Dissolve an aluminum source (such as aluminum nitrate or aluminum isopropoxide) in an appropriate solvent (such as water or ethanol), then add an acid as a catalyst to promote the hydrolysis and condensation reaction to form an alumina sol.

[0035] Crystal phase regulation: During the sol-gel process, control the crystal phase transformation of alumina by adding specific crystal seeds (such as α-alumina / γ-alumina) to form a β-alumina phase. In addition, further regulate the crystal phase by adjusting the reaction conditions.

[0036] Surface modification: During the preparation process, surface-modify the nano-alumina by adding surfactants (such as polyethylene glycol, sodium dodecyl sulfate, etc.). The surfactant can adsorb on the surface of the nanoparticles, prevent particle agglomeration, and improve its dispersibility and stability in the coating.

[0037] Magnetic field assistance: During the sol-gel process, an external magnetic field is applied to assist in controlling the orientation and arrangement of nano-aluminum oxide. The magnetic field can affect the movement and arrangement of particles, contributing to the formation of a highly ordered crystal structure.

[0038] Formation of superhard and wear-resistant film: An organic-inorganic hybrid material is added to the nano-aluminum oxide sol, and a superhard and wear-resistant film is formed on the surface of nano-aluminum oxide through a chemical reaction. This film not only improves the hardness and wear resistance of nano-aluminum oxide but also enhances its compatibility with other components. β-nano-aluminum oxide sol with special crystal phase regulation, surface modification, and orientation arrangement control is selected. During the preparation process, by adding specific crystal seeds, surfactants, and magnetic field assistance, the aluminum oxide forms a highly ordered crystal structure, and a superhard and wear-resistant film of organic-inorganic hybrid is surface-modified. This design significantly improves the hardness and wear resistance of nano-aluminum oxide, with a Mohs hardness reaching above 9.5, while enhancing its compatibility with other components, improving the overall weather resistance, anti-aging performance, and resistance to ultraviolet rays, sand, and chemical corrosion of the coating.

[0039] In some embodiments of the present invention, the particle size of the nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm.

[0040] In some embodiments of the present invention, the organosilicon-modified acrylate emulsion is a core-shell-corona structure emulsion, where the core is an organosilicon polymer with an organosilicon content of 40%-50%, the shell is an acrylate polymer, and nano-scale silica particles and carbon nanotubes are introduced into the shell layer for reinforcement, and the corona layer is an organofluorine polymer with a cross-linking function.

[0041] Specific preparation method: Preparation of the core: First, an organosilicon polymer core is prepared by emulsion polymerization. Organosilicon monomers (such as methyltrimethoxysilane, phenyltrimethoxysilane, etc.) are dissolved in a suitable solvent (such as water), an emulsifier (such as sodium dodecyl sulfate) and an initiator (such as potassium persulfate) are added, and emulsion polymerization is carried out under appropriate temperature and stirring conditions to form an organosilicon polymer core.

[0042] Preparation of the shell: Based on the organosilicon polymer core, an acrylate polymer shell is prepared by miniemulsion polymerization technology. Acrylate monomers (such as methyl methacrylate, butyl acrylate, etc.) are dissolved in the emulsion containing the organosilicon polymer core, an emulsifier and an initiator are added, and emulsion polymerization is carried out under appropriate temperature and stirring conditions to form a core-shell structure emulsion.

[0043] Nano-enhancement: Introduce nano-sized silica particles and carbon nanotubes into the shell layer for enhancement. Disperse the nano-silica particles and carbon nanotubes in an acrylate monomer solution, and make them uniformly dispersed through ultrasonic dispersion or mechanical stirring, and then introduce them into the shell layer during the emulsion polymerization process.

[0044] Preparation of the crown layer: Based on the core-shell structured emulsion, prepare an organofluoropolymer crown layer through emulsion polymerization. Dissolve an organofluorine monomer (such as perfluorooctyl acrylate) in a solution containing the core-shell structured emulsion, add an emulsifier and an initiator, and carry out emulsion polymerization under appropriate temperature and stirring conditions to form a core-shell-crown structured emulsion.

[0045] Crosslinking reaction: Introduce an organofluoropolymer with crosslinking function into the crown layer, and carry out a crosslinking reaction by adding a crosslinking agent (such as divinylbenzene, trimethylolpropane triacrylate, etc.) under appropriate temperature and stirring conditions to form an organofluoropolymer crown layer with crosslinking function.

[0046] Through the above method, the prepared organosilicon-modified acrylate emulsion has a core-shell-crown structure, where the core is an organosilicon polymer, the shell is an acrylate polymer, and nano-sized silica particles and carbon nanotubes are introduced into the shell layer for enhancement, and the crown layer is an organofluoropolymer with crosslinking function. This structural design endows the coating with excellent flexibility, weather resistance, chemical corrosion resistance and self-cleaning performance. At the same time, the nano-silica particles, carbon nanotubes and the organofluoropolymer crown layer synergistically enhance the hardness, wear resistance and stain resistance of the coating, improving the comprehensive performance of the coating.

[0047] In some embodiments of the present invention, the boron nitride nanosheet is a surface-modified boron nitride nanosheet, and the specific preparation method is as follows: Surface modification: First, put the purchased commercial nano-boron nitride (brand number PT-BN-100nm, produced by Shanghai Pantian Powder Materials Co., Ltd., with a lateral size of 100 nanometers) into a precursor solution containing organic groups, such as 3-aminopropyltriethoxysilane (APTES). Through a chemical reaction, graft organic groups on the surface of the nano-boron nitride.

[0048] The specific process is as follows:

[0049] Disperse the nano-boron nitride in an ethanol solution, add APTES, and stir at room temperature for 24 hours.

[0050] The amino group in APTES undergoes a condensation reaction with the hydroxyl group on the surface of the nano-boron nitride to form a covalent bond, thereby grafting organic groups on the surface of the nano-boron nitride.

[0051] Post-treatment: After the grafting is completed, the unreacted APTES and by-products are removed by centrifugation, then washed with ethanol multiple times, and finally dried in a vacuum oven to obtain surface-modified nano boron nitride.

[0052] Through the above method, the prepared nano boron nitride has a lateral size of 100 nanometers, high quality, high crystallinity, and organic groups with multiple functions and good compatibility with the coating system are grafted on the surface. These organic groups (such as APTES) can improve the compatibility of nano boron nitride with other components of the coating system, enabling it to form a continuous and efficient heat conduction path in the coating, significantly enhancing the thermal conductivity. At the same time, nano boron nitride has good selective emission characteristics for radiation in the infrared band, and synergistically with hollow glass microspheres, significantly enhances the radiation cooling effect. In addition, the surface-grafted organic groups can also undergo chemical reactions with other components, enhancing the overall stability and performance of the coating.

[0053] In some embodiments of the present invention, the surface of the hollow glass microspheres is coated with a multi-functional composite film composed of titanium dioxide, graphene, aluminum nitride, and silicon dioxide. The preparation method of the hollow glass microspheres includes the following steps: Pretreatment of hollow glass microspheres: First, select hollow glass microspheres with uniform wall thickness, remove surface impurities by pickling and alkali washing, and then perform a drying treatment at high temperature to ensure a clean surface.

[0054] Deposition of titanium dioxide: The sol-gel method is used to deposit titanium dioxide on the surface of the hollow glass microspheres. The pretreated hollow glass microspheres are immersed in an ethanol solution of tetrabutyl titanate, and a titanium dioxide sol film is formed on the surface of the hollow glass microspheres through hydrolysis and condensation reactions, and then dried and calcined at a certain temperature to obtain hollow glass microspheres with titanium dioxide coated on the surface.

[0055] Coating with graphene: Graphene is coated on the surface of the hollow glass microspheres coated with titanium dioxide through chemical vapor deposition (CVD) technology. The hollow glass microspheres coated with titanium dioxide are placed in a CVD reaction chamber, methane and hydrogen are introduced as carbon sources, and a chemical reaction is carried out at high temperature to deposit a graphene layer.

[0056] Deposition of aluminum nitride: Atomic layer deposition (ALD) technology is used to deposit aluminum nitride on the surface of the hollow glass microspheres coated with graphene. The hollow glass microspheres coated with graphene are placed in an ALD reaction chamber, trimethylaluminum (TMA) and ammonia are introduced as precursors, and an aluminum nitride thin film is deposited on the graphene surface through alternating chemical reactions.

[0057] Silica Coating: Finally, silica is deposited on the surface of the hollow glass microspheres coated with aluminum nitride by chemical vapor deposition. The hollow glass microspheres coated with aluminum nitride are placed in a chemical vapor deposition reaction chamber, and tetraethoxysilane (TEOS) is introduced as a precursor. A silica thin film is deposited on the surface of aluminum nitride through a gas-phase chemical reaction.

[0058] Through the above method, a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride, and silica is coated on the surface of the prepared hollow glass microspheres. This composite film not only enhances the radiative cooling ability of the hollow glass microspheres but also further improves the comprehensive performance of the coating by utilizing the high electrical conductivity of graphene, the high thermal conductivity of aluminum nitride, the photocatalytic performance of titanium dioxide, and the chemical stability of silica. In addition, the low-density characteristic of the hollow glass microspheres helps to reduce the weight of the coating, reduce the burden on the photovoltaic module, and at the same time, its internal hollow structure can play a certain role in sound insulation and heat insulation.

[0059] In some embodiments of the present invention, the particle size of the hollow glass microspheres is 45 - 50 μm.

[0060] In some embodiments of the present invention, the particle size of the hollow glass microspheres is 48 μm.

[0061] In some embodiments of the present invention, the preparation method of the shape memory polymer includes the following steps:

[0062] A1. Mix diisocyanate, polyether diol, and chain extender in a certain proportion and heat them for reaction to form a polyurethane prepolymer with a linear structure;

[0063] A2. Add a crosslinking agent and an initiator, raise the temperature and keep it warm for reaction to form a chemically crosslinked first network. Add the monomers and initiators of the second polymer network, and then heat and react to form a thermally induced shape memory polyurethane with a double network structure;

[0064] A3. Dissolve the product obtained in step A2 in a solvent, form a film by solution casting method, and then dry to remove the solvent to obtain the shape memory polymer.

[0065] In some embodiments of the present invention, in step A1, the heating reaction means reacting at 60 - 90 °C for 2 - 5 h under a protective atmosphere.

[0066] In some embodiments of the present invention, in step A2, the heating and keeping warm for reaction means raising the temperature to 95 - 110 °C and continuing the reaction for 5 - 8 hours.

[0067] In some embodiments of the present invention, in step A2, the heating and reacting again means heating to 115 - 130 °C and reacting for 6 - 10 h.

[0068] In some embodiments of the present invention, during the preparation process of the shape memory polymer, the molecular weight, molecular weight distribution, and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality.

[0069] In some embodiments of the present invention, the method for preparing the self-healing nanofibers includes the following steps:

[0070] B1. Dissolve polycaprolactone and nano-titanium dioxide in an organic solvent according to a weight ratio of (1-9):1, and form a uniform spinning solution after ultrasonic dispersion;

[0071] B2. Transfer the spinning solution to an electrospinning device with a syringe for electrospinning. After electrospinning, dry the collected nanofibers to remove the residual solvent, and obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0072] In some embodiments of the present invention, in step B2, the voltage for electrospinning is 18-25 kV, the distance between the nozzle and the collecting plate is 10-20 cm, the spinning speed is 0.8-1.5 mL / h, and electrospinning is carried out at normal temperature and pressure. A layer of aluminum foil is covered on the collecting plate for collecting self-repairing nanofibers.

[0073] In some embodiments of the present invention, the drying in step B2 means drying the collected self-healing nanofibers in a vacuum oven at 50-70 °C for 10-15 hours.

[0074] A method for preparing a coating as described above includes the following steps: Mix water, potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth-doped nano-titanium dioxide, composite zinc oxide nanoparticles and stir and disperse them. While maintaining the stirring state, sequentially add nano-silica sol and fluorosilane coupling agent, fluorocarbon surfactant and conductive carbon nanotubes, nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, boron nitride nanosheets and hollow glass microspheres, shape memory polymer and self-healing nanofibers, and finally add a dispersant, a leveling agent and an antifoaming agent to obtain the coating.

[0075] In some embodiments of the present invention, the method for preparing the coating specifically includes the following steps:

[0076] (1) Add the treated deionized water into a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogenizing emulsification, and online monitoring functions. Stir at a speed of 500 - 600 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare-earth doped nano-titanium dioxide, and composite zinc oxide nanoparticles. Stir for 50 - 90 minutes. During the stirring process, turn on the ultrasonic dispersion device in due course, with a power of 300 - 500 W, an ultrasonic time of 10 - 20 minutes each time, and an interval of 8 - 15 minutes. At the same time, use an online particle size analyzer to monitor the dispersion state of the particles in real time to ensure sufficient dispersion;

[0077] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 800 - 1200 r / min, and stir for 30 - 60 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment, and use an online rheometer to monitor the rheological properties of the system to ensure uniform mixing;

[0078] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue stirring for 30 - 60 minutes. During this period, use dynamic light scattering technology and scanning electron microscope (SEM) to monitor the dispersion state and morphology of the particles to ensure uniform dispersion;

[0079] (4) Add nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 500 - 700 r / min, and stir for 30 - 60 minutes. During the stirring process, control the temperature at 32 ± 3 °C, and use Fourier transform infrared spectrometer (FT-IR) to monitor the interaction between the emulsion and other components in real time to ensure the stability of the system;

[0080] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 50 - 90 minutes. At the same time, use a high-speed shear disperser to process the system to further refine the particles, enhance the dispersion effect, and use a thermal conductivity tester to monitor the change of the thermal conductivity of the system;

[0081] (6) Add shape memory polymer and self-healing nanofibers, and stir for 50 - 80 minutes. Use an optical microscope to observe the dispersion of microcapsules and nanofibers in the system to ensure their uniform distribution;

[0082] (7) Finally, add dispersant, leveling agent, and defoamer, and stir for 30 - 50 minutes. After the stirring is completed, use equipment such as an online viscometer, gloss meter, and surface tension meter to detect the properties such as viscosity, gloss, and surface tension of the coating to ensure that they meet the technical requirements.

[0083] The application of the coating as described above in the surface coating of a photovoltaic panel.

[0084] The beneficial effects of the present invention are:

[0085] (1) The coating of the present invention is a new photovoltaic self-cleaning nanomaterial with functions of photocatalysis, antireflection, antistatic, super weather resistance, radiative cooling and photoconversion. After being applied on the surface of a photovoltaic panel to form a coating, it can improve the power generation efficiency of the photovoltaic module, which is achieved through photocatalytic self-cleaning, antireflection and photoconversion; ensure the long-term stable operation of the photovoltaic panel, reduce dust adsorption and environmental erosion by means of antistatic and super weather resistance; and expand the application in special scenarios such as high temperature, reduce the temperature of the module by using radiative cooling, which is of great significance for improving the return on investment of photovoltaic projects and enhancing the economic competitiveness of photovoltaic energy, and can also promote energy conservation and emission reduction and contribute to sustainable development.

[0086] (2) The coating of the present invention can be cured at room temperature, reducing energy consumption and making the process more convenient. Photovoltaic modules operate in harsh outdoor environments for a long time and are prone to failure under long-term cleaning, mechanical friction and the use of cleaning agents, losing the antireflection function. The coating of the present invention can well solve the problem of repairing the photovoltaic module after the original antireflection film fails and restoring the power generation; aiming at the stubborn pain points of the existing photovoltaic coating with incomplete self-cleaning efficiency and high dependence on manual cleaning, giving full play to the advantages of the photocatalysis principle to achieve continuous and efficient self-cleaning function, greatly reducing the operation and maintenance cost, effectively improving the power generation stability, and ensuring the long-term stable operation of the photovoltaic module; the coating of the present invention can fully overcome the key problem of poor optical performance of traditional coatings, relying on the cutting-edge technologies of antireflection and photoconversion, significantly improving the light energy capture efficiency, effectively extending the power generation life of the photovoltaic module, while minimizing the harm of ultraviolet light to the module, improving the overall performance and reliability of the module, and at the same time extending the service life of the module; the coating of the present invention focuses on improving the shortcoming of electrical performance, solving the problem of electrostatic dust adsorption through innovative design, ensuring that the photovoltaic surface remains clean, providing a solid guarantee for the safety and stability of power output, and reducing the system operation risk; the coating of the present invention specifically makes up for the inherent defects of mechanical properties, and significantly enhances the anti-wear ability of the photovoltaic module with high hardness and self-repairing characteristics, enabling it to better adapt to the complex and changeable outdoor environment, effectively reducing the replacement frequency and lowering the comprehensive cost; the coating of the present invention deeply optimizes the thermal performance, relying on the functions of super heat conduction and radiative cooling, quickly dissipating the working heat, significantly improving the power generation efficiency in high-temperature environments, comprehensively enhancing the all-weather adaptability of the module, and ensuring that the photovoltaic power generation system can operate efficiently under different climate conditions. Specific Embodiments

[0087] The following further illustrates the present invention with specific embodiments.

[0088] Example 1:

[0089] A coating, comprising raw materials in the following parts by weight: potassium silicate: 25 parts; tetraethyl orthosilicate: 15 parts; nano-titanium dioxide sol: 10 parts; rare earth-doped nano-titanium dioxide: 5 parts; composite zinc oxide nanoparticles: 10 parts; nano-silica sol: 5 parts; fluorosilane coupling agent: 1 part; fluorocarbon surfactant: 1 part; conductive carbon nanotubes: 0.1 part; nano-aluminum oxide sol: 1 part; organosilicon-modified acrylate emulsion: 1 part; boron nitride nanosheets: 1 part; hollow glass microspheres: 1 part; shape memory polymer: 1 part; self-healing nanofibers: 1 part; deionized water: 22.6 parts; dispersant: 0.1 part; leveling agent: 0.1 part; defoaming agent: 0.1 part; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; the rare earth-doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium according to a weight ratio of 2:2:1.3:0.2:0.03; the core of the composite zinc oxide nanoparticles is zinc oxide with optimized lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots, and the particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of nano-silica in the nano-silica sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-scale manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoaming agent is Dehydran 1293.

[0090] Among them, the preparation method of the shape memory polymer includes the following steps:

[0091] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle according to a certain ratio, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0092] A2. Add a crosslinking agent and an initiator, raise the temperature to 100 °C, and continue the reaction for 6 hours to form a chemically crosslinked first network. Add the monomers and initiator of the second polymer network by physical blending, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution, and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0093] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain a shape memory polymer.

[0094] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0095] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and form a uniform spinning solution after ultrasonic dispersion for 30 minutes;

[0096] B2. Transfer the spinning solution to an electrospinning device with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, the spinning speed to 1 mL / h, and perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil for collecting nanofibers. After electrospinning, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent to obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0097] A preparation method of the coating as described above includes the following steps:

[0098] (1) Add deionized water to a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogeneous emulsification, and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth-doped nano-titanium dioxide, and composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, turn on the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0099] (2) Add nano-silica sol and fluorosilane coupling agent, raise the rotation speed to 1000 r / min, and stir for 50 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment;

[0100] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue stirring for 40 minutes;

[0101] (4) Add nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0102] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0103] (6) Shape memory polymer and self-healing nanofibers, stir for 60 minutes;

[0104] (7) Finally, add dispersant, leveling agent and defoaming agent, and stir for 35 minutes to obtain.

[0105] Example 2:

[0106] A coating, comprising the following raw materials in parts by weight: potassium silicate: 20 parts; tetraethyl orthosilicate: 12 parts; nano-titanium dioxide sol: 8 parts; rare earth-doped nano-titanium dioxide: 7.5 parts; composite zinc oxide nanoparticles: 12 parts; nano-silicon dioxide sol: 8 parts; fluorosilane coupling agent: 2 parts; fluorocarbon surfactant: 2 parts; conductive carbon nanotubes: 0.3 parts; nano-aluminum oxide sol: 3 parts; organosilicon-modified acrylate emulsion: 2 parts; boron nitride nanosheets: 2 parts; hollow glass microspheres: 2 parts; shape memory polymer: 2 parts; self-healing nanofibers: 2 parts; deionized water: 16.3 parts; dispersant: 0.3 parts; leveling agent: 0.3 parts; defoaming agent: 0.3 parts; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; the rare earth-doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of 2:2:1.3:0.2:0.03; the core of the composite zinc oxide nanoparticles is zinc oxide with lattice optimization, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots, and the particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silicon dioxide sol is 2.4%, and the particle size of nano-silicon dioxide in the nano-silicon dioxide sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-scale manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silicon dioxide, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoaming agent is Dehydran 1293.

[0107] Among them, the preparation method of the shape memory polymer includes the following steps:

[0108] A1. Add diisocyanate, polyether diol and chain extender into the reaction kettle according to a certain ratio. Under the protection of nitrogen, react at 80 °C for 4 hours to form a polyurethane prepolymer with a linear structure;

[0109] A2. Add a crosslinking agent and an initiator, raise the temperature to 100 °C, and continue to react for 6 hours to form a chemically crosslinked first network. By physical blending, add the monomers and initiator of the second polymer network, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0110] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain the shape memory polymer.

[0111] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0112] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and ultrasonically disperse for 30 minutes to form a uniform spinning solution;

[0113] B2. Transfer the spinning solution to an electrospinning device equipped with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, and the spinning speed to 1 mL / h. Perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil to collect the nanofibers. After the electrospinning is completed, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent to obtain the self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0114] A preparation method of a coating as described above includes the following steps:

[0115] (1) Add deionized water into a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogenizing emulsification and on-line monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth doped nano-titanium dioxide, composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, start the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0116] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 1000 r / min, and stir for 50 minutes. Meanwhile, introduce nitrogen gas into the mixed system to maintain an inert environment;

[0117] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue stirring for 40 minutes;

[0118] (4) Add nano-alumina sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0119] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0120] (6) Shape memory polymer and self-healing nanofibers, stir for 60 minutes;

[0121] (7) Finally, add dispersant, leveling agent and defoamer, and stir for 35 minutes to obtain the product.

[0122] Example 3:

[0123] A coating, comprising raw materials in the following parts by weight: potassium silicate: 28 parts; tetraethyl orthosilicate: 10 parts; nano-titanium dioxide sol: 5 parts; rare earth-doped nano-titanium dioxide: 10 parts; composite zinc oxide nanoparticles: 10 parts; nano-silica sol: 5 parts; fluorosilane coupling agent: 3 parts; fluorocarbon surfactant: 2 parts; conductive carbon nanotubes: 0.5 parts; nano-aluminum oxide sol: 5 parts; organosilicon-modified acrylate emulsion: 3 parts; boron nitride nanosheets: 2 parts; hollow glass microspheres: 2 parts; shape memory polymer: 1 part; self-healing nanofibers: 1 part; deionized water: 11.9 parts; dispersant: 0.8 part; leveling agent: 0.5 part; defoaming agent: 0.3 part; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; rare earth elements are doped in the rare earth-doped nano-titanium dioxide, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium according to the weight ratio of 2:2:1.3:0.2:0.03; the core of the composite zinc oxide nanoparticles is zinc oxide with optimized lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots, and the particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of nano-silica in the nano-silica sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-scale manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoaming agent is Dehydran 1293.

[0124] Among them, the preparation method of the shape memory polymer includes the following steps:

[0125] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle in a certain proportion, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0126] A2. Add a crosslinking agent and an initiator, heat up to 100 °C, and continue the reaction for 6 hours to form a chemically crosslinked first network. Add the monomers and initiator of the second polymer network by physical blending, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution, and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0127] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain a shape memory polymer.

[0128] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0129] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and form a uniform spinning solution after ultrasonic dispersion for 30 minutes;

[0130] B2. Transfer the spinning solution to an electrospinning device equipped with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, the spinning speed to 1 mL / h, and perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil to collect the nanofibers. After the electrospinning is completed, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent, and obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0131] A preparation method of the coating as described above includes the following steps:

[0132] (1) Add deionized water to a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogenizing emulsification, and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth-doped nano-titanium dioxide, and composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, turn on the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0133] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 1000 r / min, and stir for 50 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment;

[0134] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue stirring for 40 minutes;

[0135] (4) Add nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0136] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0137] (6) Shape memory polymer and self-healing nanofibers, stir for 60 minutes;

[0138] (7) Finally, add dispersant, leveling agent and defoamer, stir for 35 minutes to obtain.

[0139] Example 4:

[0140] A coating, comprising the following raw materials in parts by weight: potassium silicate: 15 parts; tetraethyl orthosilicate: 20 parts; nano-titanium dioxide sol: 5 parts; rare earth-doped nano-titanium dioxide: 5 parts; composite zinc oxide nanoparticles: 10 parts; nano-silica sol: 5 parts; fluorosilane coupling agent: 1 part; fluorocarbon surfactant: 1 part; conductive carbon nanotubes: 0.8 part; nano-aluminum oxide sol: 2 parts; organosilicon-modified acrylate emulsion: 2 parts; boron nitride nanosheets: 2 parts; hollow glass microspheres: 2 parts; shape memory polymer: 2 parts; self-healing nanofibers: 2 parts; deionized water: 24.7 parts; dispersant: 1 part; leveling agent: 1 part; defoamer: 0.5 part; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; rare earth-doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of 2:2:1.3:0.2:0.03; the core of the composite zinc oxide nanoparticles is zinc oxide with optimized crystal lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots. The particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of nano-silica in the nano-silica sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-scale manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoamer is Dehydran 1293.

[0141] Among them, the preparation method of the shape memory polymer includes the following steps:

[0142] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle in a certain proportion, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0143] A2. Add a crosslinking agent and an initiator, raise the temperature to 100 °C, and continue to react for 6 hours to form a chemically crosslinked first network. By physical blending, add the monomers and initiator of the second polymer network, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0144] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain the shape memory polymer.

[0145] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0146] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and ultrasonically disperse for 30 minutes to form a uniform spinning solution;

[0147] B2. Transfer the spinning solution to an electrospinning device with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, the spinning speed to 1 mL / h, and perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil for collecting nanofibers. After electrospinning, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent to obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0148] A preparation method of a coating as described above includes the following steps:

[0149] (1) Add deionized water into a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogeneous emulsification and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth doped nano-titanium dioxide, composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, start the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0150] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 1000 r / min, and stir for 50 minutes. Meanwhile, introduce nitrogen gas into the mixed system to maintain an inert environment;

[0151] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue stirring for 40 minutes;

[0152] (4) Add nano-alumina sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0153] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0154] (6) Shape memory polymer and self-healing nanofibers, and stir for 60 minutes;

[0155] (7) Finally, add dispersant, leveling agent and defoamer, and stir for 35 minutes to obtain the product.

[0156] Comparative Example 1: (Compared with Example 1, the only difference is that it does not contain nano-titanium dioxide sol and rare earth-doped nano-titanium dioxide)

[0157] A coating, comprising raw materials in the following parts by weight: potassium silicate: 25 parts; tetraethyl orthosilicate: 15 parts; composite zinc oxide nanoparticles: 10 parts; nano-silica sol: 5 parts; fluorosilane coupling agent: 1 part; fluorocarbon surfactant: 1 part; conductive carbon nanotubes: 0.1 part; nano-alumina sol: 1 part; organosilicon-modified acrylate emulsion: 1 part; boron nitride nanosheets: 1 part; hollow glass microspheres: 1 part; shape memory polymer: 1 part; self-healing nanofibers: 1 part; deionized water: 22.6 parts; dispersant: 0.1 part; leveling agent: 0.1 part; defoaming agent: 0.1 part; the core of the composite zinc oxide nanoparticles is zinc oxide with optimized crystal lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots. The particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of the nano-silica in the nano-silica sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nanoscale manganese dioxide particles and graphene quantum dots; the nano-alumina sol is β-nano-alumina sol, and the particle size of the nano-alumina in the nano-alumina sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica. The particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers655; the leveling agent is Flow 370; the defoaming agent is Dehydran 1293.

[0158] Among them, the preparation method of the shape memory polymer includes the following steps:

[0159] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle in a certain proportion, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0160] A2. Add a crosslinking agent and an initiator, raise the temperature to 100 °C, and continue to react for 6 hours to form a chemically crosslinked first network. By physical blending, add monomers and initiators of the second polymer network and react at 120 °C for 8 hours to form a double-network-structured thermally induced shape memory polyurethane. During the reaction process, the molecular weight, molecular weight distribution and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0161] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain the shape memory polymer.

[0162] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0163] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and ultrasonically disperse for 30 minutes to form a uniform spinning solution;

[0164] B2. Transfer the spinning solution to an electrospinning device with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, the spinning speed to 1 mL / h, and perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil to collect the nanofibers. After the spinning is completed, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent, and obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0165] A preparation method of the coating as described above includes the following steps:

[0166] (1) Add deionized water to a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogeneous emulsification, and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, and composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, turn on the ultrasonic dispersion device in a timely manner, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0167] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 1000 r / min, and stir for 50 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment;

[0168] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue to stir for 40 minutes;

[0169] (4) Add nano-alumina sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0170] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0171] (6) Shape memory polymer and self-healing nanofibers, and stir for 60 minutes;

[0172] (7) Finally, add a dispersant, a leveling agent, and an antifoaming agent, and stir for 35 minutes to obtain.

[0173] Comparative Example 2: (Compared with Example 1, the only difference is that it does not contain composite zinc oxide nanoparticles)

[0174] A coating, comprising raw materials in the following parts by weight: potassium silicate: 25 parts; tetraethyl orthosilicate: 15 parts; nano-titanium dioxide sol: 10 parts; rare earth doped nano-titanium dioxide: 5 parts; nano-silica sol: 5 parts; fluorosilane coupling agent: 1 part; fluorocarbon surfactant: 1 part; conductive carbon nanotubes: 0.1 part; nano-aluminum oxide sol: 1 part; organosilicon modified acrylate emulsion: 1 part; boron nitride nanosheets: 1 part; hollow glass microspheres: 1 part; shape memory polymer: 1 part; self-healing nanofibers: 1 part; deionized water: 22.6 parts; dispersant: 0.1 part; leveling agent: 0.1 part; defoaming agent: 0.1 part; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; the rare earth doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of 2:2:1.3:0.2:0.03; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of nano-silica in the nano-silica sol is 13.35 nm; the fluorine content of the fluorosilane coupling agent is 45 wt%; the fluorocarbon surfactant is perfluorooctylsulfonyl polyoxyethylene ether; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-sized manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoaming agent is Dehydran1293.

[0175] Among them, the preparation method of the shape memory polymer includes the following steps:

[0176] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle in a certain proportion, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0177] A2. Add a crosslinking agent and an initiator, raise the temperature to 100 °C, and continue to react for 6 hours to form a chemically crosslinked first network. Add the monomers and initiator of the second polymer network by physical blending, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0178] A3. Dissolve the product obtained in step A2 in a solvent, form a film by solution casting method, and then dry it in a vacuum oven to remove the solvent, obtaining a shape memory polymer.

[0179] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0180] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and ultrasonically disperse for 30 minutes to form a uniform spinning solution;

[0181] B2. Transfer the spinning solution to an electrospinning device equipped with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, the spinning speed to 1 mL / h, and perform electrospinning at normal temperature and pressure. Cover a layer of aluminum foil on the collecting plate to collect the nanofibers. After the electrospinning is completed, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent, obtaining self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0182] A preparation method of the coating as described above includes the following steps:

[0183] (1) Add deionized water to a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogeneous emulsification and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, and rare earth-doped nano-titanium dioxide, and stir for 70 minutes. During the stirring process, start the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0184] (2) Add nano-silica sol and fluorosilane coupling agent, increase the rotation speed to 1000 r / min, and stir for 50 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment;

[0185] (3) Add fluorocarbon surfactant and conductive carbon nanotubes, and continue to stir for 40 minutes;

[0186] (4) Add nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0187] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0188] (6) Shape memory polymer and self-healing nanofibers, and stir for 60 minutes;

[0189] (7) Finally, add a dispersant, a leveling agent and an antifoaming agent, and stir for 35 minutes to obtain.

[0190] Comparative Example 3: (Compared with Example 1, the only difference is that it does not contain fluorosilane coupling agent and fluorocarbon surfactant)

[0191] A coating, comprising raw materials in the following parts by weight: potassium silicate: 25 parts; tetraethyl orthosilicate: 15 parts; nano-titanium dioxide sol: 10 parts; rare earth doped nano-titanium dioxide: 5 parts; composite zinc oxide nanoparticles: 10 parts; nano-silica sol: 5 parts; conductive carbon nanotubes: 0.1 part; nano-aluminum oxide sol: 1 part; organosilicon modified acrylate emulsion: 1 part; boron nitride nanosheets: 1 part; hollow glass microspheres: 1 part; shape memory polymer: 1 part; self-healing nanofibers: 1 part; deionized water: 22.6 parts; dispersant: 0.1 part; leveling agent: 0.1 part; defoaming agent: 0.1 part; the particle size of nano-titanium dioxide in the nano-titanium dioxide sol is 17.3 nm; rare earth doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of 2:2:1.3:0.2:0.03; the core of the composite zinc oxide nanoparticles is zinc oxide with optimized lattice, the middle shell layer is a ternary composite layer of titanium dioxide-zinc oxide-cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is coated with a corona layer composed of titanium dioxide quantum dots and carbon nanodots, and the particle size of the composite zinc oxide nanoparticles is 28.9 nm; the light transmittance increase rate of the nano-silica sol is 2.4%, and the particle size of nano-silica in the nano-silica sol is 13.35 nm; the surface of the conductive carbon nanotubes is coated with a layer of polyaniline and loaded with nano-scale manganese dioxide particles and graphene quantum dots; the nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of nano-aluminum oxide in the nano-aluminum oxide sol is 23.9 nm; the boron nitride nanosheets are surface-modified boron nitride nanosheets. The surface of the hollow glass microspheres is coated with a multifunctional composite film composed of titanium dioxide, graphene, aluminum nitride and silica, and the particle size of the hollow glass microspheres is 48 μm; the dispersant is Dispers 655; the leveling agent is Flow 370; the defoaming agent is Dehydran 1293.

[0192] Among them, the preparation method of the shape memory polymer includes the following steps:

[0193] A1. Add diisocyanate, polyether diol and chain extender into a reaction kettle in a certain proportion, and react at 80 °C for 4 hours under nitrogen protection to form a polyurethane prepolymer with a linear structure;

[0194] A2. Add a crosslinking agent and an initiator, heat up to 100 °C, and continue the reaction for 6 hours to form a chemically crosslinked first network. Add the monomers and initiator of the second polymer network by physical blending, and react at 120 °C for 8 hours to form a thermally induced shape memory polyurethane with a double network structure. During the reaction process, the molecular weight, molecular weight distribution, and glass transition temperature of the polymer are monitored in real time by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) to ensure product quality;

[0195] A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry it in a vacuum oven to remove the solvent to obtain a shape memory polymer.

[0196] Among them, the preparation method of the self-healing nanofibers includes the following steps:

[0197] B1. Dissolve polycaprolactone and nano-titanium dioxide in a mixed solvent of chloroform and dimethylformamide according to a weight ratio of 5:1, and form a uniform spinning solution after ultrasonic dispersion for 30 minutes;

[0198] B2. Transfer the spinning solution to an electrospinning device equipped with a syringe, set the voltage to 20 kV, the distance between the nozzle and the collecting plate to 15 cm, and the spinning speed to 1 mL / h. Perform electrospinning at normal temperature and pressure. Cover the collecting plate with a layer of aluminum foil to collect the nanofibers. After the electrospinning is completed, dry the collected nanofibers in a vacuum oven at 60 °C for 12 hours to remove the residual solvent, and obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

[0199] A preparation method of the coating as described above includes the following steps:

[0200] (1) Add deionized water to a multifunctional mixing device equipped with high-speed dispersion, ultrasonic dispersion, planetary stirring, homogenizing emulsification, and online monitoring functions, stir at a speed of 550 r / min, and sequentially add potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare earth-doped nano-titanium dioxide, and composite zinc oxide nanoparticles, and stir for 70 minutes. During the stirring process, turn on the ultrasonic dispersion device in due course, with a power of 350 W, an ultrasonic time of 15 minutes each time, and an interval of 10 minutes;

[0201] (2) Add nano-silica sol, increase the rotation speed to 1000 r / min, and stir for 50 minutes. At the same time, introduce nitrogen into the mixing system to maintain an inert environment;

[0202] (3) Add conductive carbon nanotubes and continue stirring for 40 minutes;

[0203] (4) Add nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, reduce the rotation speed to 600 r / min, stir for 50 minutes, and control the temperature at 32 °C;

[0204] (5) Add boron nitride nanosheets and hollow glass microspheres, and stir for 70 minutes;

[0205] (6) Shape memory polymer and self-healing nanofibers, stir for 60 minutes;

[0206] (7) Finally, add dispersant, leveling agent and defoaming agent, stir for 35 minutes, and then it is obtained.

[0207] Test examples:

[0208] Carry out relevant performance tests on the coatings prepared in the examples and comparative examples respectively. The test results are shown in Table 1:

[0209] Test methods

[0210] (1) Transmittance test: In the wavelength range of 380 nm - 1100 nm, use a spectral transmittance tester for detection.

[0211] (2) Self-cleaning efficiency test: Under the dust and oil pollution conditions simulating the actual environment, observe the self-cleaning effect of the coating surface. The coating can quickly restore the clean surface after natural rainfall or simple rinsing, and the self-cleaning efficiency can reach more than 90%.

[0212] (3) Pencil hardness: According to the GB / T 6739-2020 standard, use a Japanese Mitsubishi pencil for testing. The hardness of the coating can reach 4H - 5H, and it can resist slight scratches in daily use.

[0213] (4) Adhesion test: Refer to the GB / T 9286-2021 standard, and use the cross-cut method or tape adhesion method for testing. The adhesion between the coating and the substrate can reach level 0, ensuring that the coating will not fall off during long-term use.

[0214] (5) UV aging test: According to the ISO 4892-3 standard, irradiate in a UV aging chamber for a certain period of time. After more than 1000 h of UV aging, the coating can still maintain good optical properties, self-cleaning properties and mechanical properties, such as the transmittance decrease does not exceed 1%, and the contact angle change does not exceed 10°.

[0215] (6) PCT test: Refer to UL1703, put the coated glass into a PCT test chamber at 121 °C, 100% RH, 2 atm, and impact in a high-temperature, high-humidity and high-pressure environment for 48 h. Observe the appearance of the coated glass and test the change of transmittance. If the appearance of the coated glass has no film peeling or color change, and the transmittance attenuation ≤ 1%, it passes the test and is qualified.

[0216] Table 1. Test Results of Coating Performance

[0217]

[0218] As can be seen from Table 1, the coating prepared from the coating material of the present invention has the characteristics of high transmittance, good self-cleaning effect, high hardness, good adhesion and excellent weather resistance. Its light transmittance can reach more than 94.1%, the self-cleaning efficiency can reach more than 94%, the hardness can reach more than 3H, and the adhesion can reach grade 0. Compared with Example 1, in Comparative Example 1, less nano-titanium dioxide sol and rare-earth doped nano-titanium dioxide were added, and the others were the same as in Example 1. The results showed that nano-titanium dioxide sol and rare-earth doped nano-titanium dioxide enhanced the migration rate of photo-generated carriers and the ability to inhibit recombination, greatly improving the photocatalytic performance and the efficiency of light conversion into blue-green light, thereby enhancing the ability of the coating to decompose organic substances through photocatalysis. In addition, nano-titanium dioxide is beneficial to improving the ultraviolet resistance of the coating. Compared with Example 1, in Comparative Example 2, less composite zinc oxide nanoparticles were added. The results showed that nano-zinc oxide helps to inhibit the growth of microorganisms on the coating surface. Its unique structure not only enhances the light absorption, scattering and catalytic activity, but carbon nanodots improve the electron conduction ability of the coating, further enhancing the photocatalytic efficiency. Compared with Example 1, in Comparative Example 3, less fluorosilane coupling agent and fluorocarbon surfactant were added. The results showed that the self-cleaning efficiency, pencil hardness, adhesion and ultraviolet weather resistance of the coating material in Comparative Example 3 decreased significantly, indicating that the fluorosilane coupling agent and fluorocarbon surfactant played a promoting role in these aspects. The active groups chemically react with the inorganic film-forming substances to form strong chemical bonds, enhancing the interfacial binding force; the flexible chain segments endow the coating with excellent flexibility, enabling it to better adapt to the thermal expansion and contraction of photovoltaic modules at different temperatures; the photo-responsive groups undergo structural changes under light illumination, further reducing the surface energy, improving the self-cleaning performance, and enhancing the photocatalytic effect to a certain extent.

[0219] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A coating, characterized in that: It includes the following raw materials: Potassium silicate; tetraethyl orthosilicate; nano-titanium dioxide sol; rare earth doped nano-titanium dioxide; composite zinc oxide nanoparticles; nano-silica sol; fluorosilane coupling agent; fluorocarbon surfactant; conductive carbon nanotubes; nano-aluminum oxide sol; organosilicon modified acrylate emulsion; boron nitride nanosheets; hollow glass microspheres; shape memory polymer; self-healing nanofibers.

2. The coating according to claim 1, wherein: The coating includes the following raw materials in parts by weight: Potassium silicate: 10 - 35 parts; tetraethyl orthosilicate: 10 - 30 parts; nano-titanium dioxide sol: 5 - 15 parts; rare earth doped nano-titanium dioxide: 5 - 10 parts; composite zinc oxide nanoparticles: 10 - 20 parts; nano-silica sol: 5 - 15 parts; fluorosilane coupling agent: 1 - 5 parts; fluorocarbon surfactant: 1 - 5 parts; conductive carbon nanotubes: 0.1 - 1 part; nano-aluminum oxide sol: 1 - 10 parts; Organosilicon modified acrylate emulsion: 1 - 10 parts; boron nitride nanosheets: 1 - 5 parts; Hollow glass microspheres: 1 - 5 parts; shape memory polymer: 1 - 5 parts; self-healing nanofibers: 1 - 5 parts.

3. A coating according to claim 1, characterized in that: The rare earth doped nano-titanium dioxide is doped with rare earth elements, and the rare earth elements are composed of lanthanum, cerium, yttrium, erbium and praseodymium in a weight ratio of (1 - 3):(1 - 3):(1.1 - 1.5):(0.1 - 0.3):(0.01 - 0.05).

4. A coating according to claim 1, wherein: The core of the composite zinc oxide nanoparticles is zinc oxide with optimized lattice, the middle shell layer is a ternary composite layer of titanium dioxide - zinc oxide - cadmium sulfide, the outer layer is loaded with nano-silver satellite particles, and the outermost layer is wrapped with a corona layer composed of titanium dioxide quantum dots and carbon nanodots.

5. A coating according to claim 1, characterized in that: The surface of the conductive carbon nanotubes is coated with a layer of conductive polymer and loaded with nano-scale metal oxide particles and graphene quantum dots.

6. A paint according to claim 1, characterized in that: The nano-aluminum oxide sol is β-nano-aluminum oxide sol, and the particle size of the nano-aluminum oxide sol is 20 - 25 nm.

7. A coating according to claim 1, wherein: The preparation method of the shape memory polymer includes the following steps: A1. Mix diisocyanate, polyether diol and chain extender in a certain proportion and heat react to form a polyurethane prepolymer with a linear structure; A2. Add a crosslinking agent and an initiator, raise the temperature and keep the reaction, form a chemically crosslinked first network, add the monomers and initiators of the second polymer network, and then heat and react to form a thermally induced shape memory polyurethane with a double network structure; A3. Dissolve the product obtained in step A2 in a solvent, make a film by solution casting method, and then dry to remove the solvent to obtain a shape memory polymer.

8. A coating according to claim 1, characterized in that: The preparation method of the self-healing nanofibers includes the following steps: B1. Dissolve polycaprolactone and nano-titanium dioxide in an organic solvent according to a weight ratio of (1 - 9):1, and ultrasonically disperse to form a uniform spinning solution; B2. Transfer the spinning solution to an electrospinning device with a syringe for electrospinning. After electrospinning, dry the collected nanofibers to remove the residual solvent to obtain self-healing nanofibers composed of polycaprolactone and nano-titanium dioxide.

9. A method for preparing a coating according to any one of claims 1 to 8, characterized in that: It includes the following steps: Mix water, potassium silicate, tetraethyl orthosilicate, nano-titanium dioxide sol, rare-earth doped nano-titanium dioxide, composite zinc oxide nanoparticles, and stir and disperse them. While maintaining the stirring state, sequentially add nano-silica sol and fluorosilane coupling agent, fluorocarbon surfactant and conductive carbon nanotubes, nano-aluminum oxide sol and organosilicon-modified acrylate emulsion, boron nitride nanosheets and hollow glass microspheres, shape memory polymer and self-healing nanofibers. Finally, add a dispersant, a leveling agent and an antifoaming agent to obtain the product.

10. Application of the coating according to any one of claims 1 to 8 in the surface coating of a photovoltaic panel.

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