Preparation method of high-light-transmission anti-aging cesium tungsten bronze / double-rhenium synergistic enhanced NIR shielding film

Abstract

According to the preparation method of the high-light-transmission anti-aging cesium tungsten bronze / double-rhenium synergistically-enhanced NIR shielding thin film, a cesium tungsten bronze-rhenium trioxide heterojunction is introduced into prepared NIR shielding powder on the basis of traditional cesium tungsten bronze, and the NIR shielding efficiency of the product thin film is enhanced. And meanwhile, the strength of the film is enhanced by doping a trace amount of elemental rhenium, so that the thickness of the prepared film is lower than that of a commercial NIR shielding film, and the light transmittance of the film is improved. The anti-aging performance of the film is also enhanced by doping the elemental rhenium, and the service life of the film is prolonged. Compared with a commercial NIR shielding film, the finished product film has higher light transmittance and higher NIR absorptivity, and the glass temperature rises to 47-54 DEG C after the film is irradiated for 60 minutes under a 250 W infrared lamp. And the NIR shielding performance of the film is not obviously reduced after 50 times of circulation under an extreme thermal shock experiment at 5-80 DEG C.

Description

Technical Field

[0001] The present invention relates to the field of organic-inorganic composite materials, and specifically, to a preparation method of cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding powder with high light transmittance and anti-aging property and its film, and an application thereof in the field of heat insulation materials. Background Art

[0002] Building energy consumption refers to the energy consumed during the use of buildings, mainly including air conditioning and refrigeration, lighting systems, electrical equipment, etc.

[0003] The energy consumption of air conditioning and refrigeration accounts for a considerable part of building energy consumption. As pointed out by the second law of thermodynamics, energy always spontaneously transfers from high to low. In summer, the temperature outside the building is high, and heat spontaneously transfers into the building, thus increasing the energy consumption of air conditioning refrigeration. Therefore, restricting the free flow of heat energy between the inside and outside of the building can control the increase of building energy consumption to a certain extent. The essence of heat energy flow is the transfer of light energy. The solar spectrum mainly consists of visible light, ultraviolet light, and infrared light, among which near-infrared light (NIR) in the infrared light accounts for 51% of the entire solar spectrum, with the largest proportion and the most heat energy generated. Controlling the energy of near-infrared light is considered the most effective method to control the transfer of light energy. Currently, the commonly used method is to cover a layer of heat insulation composite material on the outer layer of building glass.

[0004] Currently, the methods for manufacturing NIR absorption materials for buildings generally include the following three aspects.

[0005] 1) By doping various metal ions with complementary functions in the glass to gradually improve the performance of the glass or film. For example, in the Chinese patent "Near-infrared light absorbing glass, element, and filter (CN 114702241 A)", doping Cu 2+ is used to endow the glass with near-infrared light absorption performance; doping P 5+ in the glass to promote the formation of the glass and further improve the near-infrared absorption performance of the glass; doping Al 3+ to increase the stability of the glass, improve the strength of the glass, and improve the weather resistance of the glass; doping Ln 3+ (Ln 3+ is La 3+ 、Gd 3+ 、Y 3+ one or more of them) to improve the visible light transmittance of the glass and improve the chemical stability and hardness of the glass.

[0006] 2) Directly synthesize organic or inorganic substances with NIR absorption performance and evenly coat them on the glass surface to form a film. For example, in the Chinese patent "A Near-Infrared Strong Absorbing Dye and Its Preparation Method and Application (CN 113480869 A)", by synthesizing 2-(3-cyano-4-(2-(3-(-2-(4-cyano-5-(dicyanomethyl)-2,2-dimethylfuran-3(2H)-ylidene)ethylidene)-2-(piperazin-1-yl)cyclohex-1-en-1-yl)vinyl)-5,5-dimethylfuran-2(5H)-ylidene)propanedinitrile and coating it on the glass surface to achieve the purpose of shielding near-infrared light energy.

[0007] 3) Shield NIR by doping specific nano-powders in a polymer and making a film. For example, in the Chinese patent "A Preparation Method of Silicon Dioxide / Cesium Tungsten Bronze Near-Infrared Shielding Composite Fiber (CN 115491791 A)", tetraethyl orthosilicate is used as the silicon source, ethanol as the solvent, and oxalic acid as the catalyst to prepare a tetraethyl orthosilicate hydrolysis solution; tungsten powder is used as the tungsten source and cesium chloride as the cesium source, and a sol-gel method is used to prepare cesium tungsten bronze composite fiber.

[0008] Existing commonly used NIR shielding materials include nano-indium tin oxide (ITO), nano-antimony tin oxide (ATO), nano-lanthanum hexaboride (LaB6), nano-cesium tungsten bronze particles, etc. Although there are many NIR shielding materials and they have been widely used, the following problems still need to be urgently solved: 1) The visible light transmittance is limited, generally lower than 75%. The material has a certain shielding effect on visible light, which will affect the transparency of the glass; 2) The absorption band is limited. For example, ITO and ATO materials can usually maintain a relatively high visible light transmittance, but they can only absorb the band with a wavelength greater than 1500 nm, and the heat insulation effect is limited; 3) Other problems caused by the composition of the material. For example, although cesium tungsten bronze (Cs x WO3, 0 < x < 1) achieves a good balance between visible light transmittance and absorption band, organic materials often release free H radicals under ultraviolet radiation, and the latter will react with W 6+ to generate W 5+ which will cause the material to turn blue and affect the visual effect. Summary of the Invention

[0009] In view of the problems existing in the existing NIR shielding materials, such as low visible light transmittance and limited absorption band, the present invention provides a preparation method of a cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding powder and its film with high light transmittance and anti-aging performance.

[0010] (1) Object of the Invention The first object of the present invention is to provide a high-transmittance cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding powder, which has a higher visible light transmittance than existing materials due to the presence of cesium tungsten bronze and rhenium trioxide heterojunction.

[0011] The second object of the present invention is to provide an anti-aging cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding film. The addition of rhenium improves the ductility and strength of the film while enhancing the anti-aging performance of the film, so that the final product has a longer life. In addition, the addition of rhenium optimizes the W 6+ The electronic structure of the film solves the problem of the blue film turning affected by visual effects.

[0012] The third object of the present invention is to provide a cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding film, which has a stronger shielding effect on near-infrared light than existing materials.

[0013] The fourth object of the present invention is to provide a method for preparing a high-transmittance and anti-aging cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding powder and its film, the preparation method has readily available raw materials, a simple and safe process, and is easy to scale up for mass production.

[0014] (2) Technical solution In order to achieve the above purpose, the following technical solutions are adopted: For the first purpose of "providing a highly transmittance cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding powder", the composite powder solid is prepared into a nano-scale high-efficiency NIR shielding composite powder, and the LSPR characteristic peak of the powder is regulated to shift to the near-infrared light region by introducing a cesium tungsten bronze-rhenium trioxide heterojunction. In addition, the low absorption rate of rhenium trioxide in the visible light region achieves high transmittance of the product. It is dispersed in a molten organic polymer material and extruded using a hydraulic film forming machine. The thickness of the resulting film is between 0.3 mm and 0.4 mm. Such a thickness gives the film a transmittance of more than 78% and a haze value of less than 31%. At the same time, the doping of rhenium also gives the film higher strength, making it less likely to break at such a thickness.

[0015] For the second purpose of "providing an anti-aging cesium tungsten bronze / dual rhenium synergistically enhanced NIR shielding film", the strength and tensile properties of the film were improved by introducing rhenium elements that were partially reduced on the bulk surface during the reaction, while the film aging was inhibited, thus greatly improving the life of the film. o C~80 o C was cycled 50 times under the extreme thermal shock test without any significant decrease in NIR shielding performance.

[0016] For the third objective, "A cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film", by introducing a cesium tungsten bronze-rhenium trioxide heterojunction, the strong LSPR synergy between rhenium trioxide and cesium tungsten bronze in the 800 nm - 1500 nm range endows the material with more efficient NIR shielding performance.

[0017] For the fourth objective, "Providing a preparation method for a high-transparency pure-phase cesium tungsten rhenium bronze NIR shielding film", high-energy ball milling is used to ensure complete mixing of the solid-phase reactants. In the hydrothermal synthesis, the temperature of the hydrothermal method is controlled to increase stepwise to ensure complete reaction in the liquid phase; the particle size of the composite powder is ensured to be between 15 nm and 50 nm by the linkage of a high-speed shearing machine and a nano-grinding machine; the prepared film-forming raw materials are ensured to be uniform by a two-stage stirring method of stirring at 90 - 180 °C until the solution is clear and transparent, then continuing to stir at a speed of 200 r / min - 300 r / min for 3 h, and maintaining a constant temperature of 90 °C and magnetic stirring for more than 6 h after adding the composite powder; the air in the raw materials is removed by heating the film-forming raw materials in a heating furnace at 90 °C for 6 h, and the internal stress between polymer molecules and composite powder particles is eliminated as much as possible; the thickness of the film is further stabilized by using a hydraulic film-forming machine to shape and press the film; finally, the film is placed in an oven, maintained at a constant temperature of 50 °C, and dried by passing nitrogen for 12 h to achieve the purpose of fixing the film form.

[0018] For the above technical solutions, the details are further described as follows: A preparation method for a high-transparency and anti-aging cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding powder and its film: First, prepare a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium, add it to an organic phase after high-energy grinding, and make a film. The specific preparation method includes the following steps: 1) Solid-phase method. Mix the rhenium source, tungsten source, and cesium source according to a specific method and evaporate to dryness. Place the product in a high-energy ball mill and ball mill at a rotation speed of 1000 rpm for 6 - 12 h, and then heat the ball-milled product in a 5% H2 / Ar mixed gas at 600 o °C for 2 h to obtain a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium.

[0019] Hydrothermal method. Mix the rhenium source, tungsten source, and cesium source according to a molar ratio of x:1 for Cs to W+Re, where 0.166 < x < 0.33, and add it to a hydrothermal reaction solution (a solution with a water-ethanol volume ratio of 2:1) according to a specific method. Under the condition of maintaining a constant temperature of 50 °C, mechanical stirring is used to ensure sufficient mixing. Subsequently, transfer the mixed solution to a reaction kettle, and adopt the following heating scheme to ensure the completeness of the reaction: take 180 °C as the starting temperature, then increase the temperature by 10 °C per hour, continue to increase the temperature for 6 h, and then at 240 oInsulate at C for 120 min. After the heating process ends, slowly cool it for another 6 h to gradually restore it to room temperature; then evaporate the obtained product solution to dryness at a temperature of 120 °C to 140 °C. Grind the obtained solid with a quartz mortar and pass it through a 40-mesh sieve to finally obtain the three-phase composite powder.

[0020] 2) Preparation of cesium tungsten rhenium bronze slurry: Use a high-speed shearer to crush the three-phase composite powder solid at a rotation speed of 5000 rpm for 15 - 35 min, then place it in a nano grinder and grind it at a rotation speed of 1500 rpm for 30 - 120 min. Then place it in a centrifuge and centrifuge it at 5000 r / min to 8000 r / min for 3 min to 15 min. The particle size of the obtained powder is 15 nm to 35 nm. Finally, add water, a super dispersant, and propylene glycol methyl ether acetate to disperse and obtain the three-phase composite slurry of cesium tungsten bronze, rhenium trioxide, and rhenium. 3) Preparation of film raw materials: Weigh the organic polymer raw materials and add them to ultrapure water. Stir at 90 °C to 180 °C until the solution is clear and transparent, and then continue to stir at a speed of 300 r / min for 3 h. Place the obtained film-forming raw materials in a heating furnace, pass nitrogen, and heat at 90 °C for 6 h. Weigh the three-phase composite slurry and add it to the solution to make the mass-volume fraction calculated by cesium in the solution 8 g / L and keep it at a constant temperature of 90 - 180 °C, and stir magnetically for 6 h. Then, place the finished product in an oven, pass nitrogen, and heat at a constant temperature of 90 - 180 °C for 6 h. 4) Preparation of NIR shielding film: Use a 25 - 35 µm Mayer rod to coat the film raw materials onto the glass, and place it in an oven filled with N2 and shape it at 50 o C for 12 h and then cool it to room temperature to obtain a NIR shielding film with high light transmittance. The thickness of the film is between 0.25 mm and 0.35 mm, the visible light transmittance is greater than 80%, the near-infrared light absorption rate is greater than 90%, and the ultraviolet light absorption rate is greater than 97%.

[0021] Preferably, the rhenium source in step 1) is one of rhenium compounds such as NH4ReO4, ReCl5, Re2O7, Re2O5, ReO2, etc., the cesium source is one of cesium compounds such as CsOH·H2O, Cs2CO3, Cs2O, Cs 11 O3, Cs4O, Cs7O, Cs2O, etc., and the tungsten source is WO3.

[0022] Preferably, the super dispersant in step 2) is at least one of polyester-based super dispersants, polyether-based super dispersants, polyacrylate-based super dispersants, polyolefin-based super dispersants, oleic acid, isobutanol, and paraffin oil.

[0023] Preferably, the organic polymer raw material in step 3) is one of transparent organic polymer materials such as polyethylene, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, etc.

[0024] Preferably, the specific mixing method is to first place the tungsten source and the rhenium source in anhydrous ethanol and mechanically stir at a speed of 300 r / min for 30 min, and then at 70 o The product was then placed in deionized water together with the cesium source and continued to be heated at 100 r / min at 95 o C until evaporated to dryness.

[0025] Preferably, the ratio of the organic polymer raw material to ultrapure water in step (3) is 3 g:50 ml.

[0026] Preferably, in step (4), the hydraulic film forming machine is at 5 kg / cm 2 ~ 500 kg / cm 2 The mold was pressed under pressure for 30 minutes.

[0027] Preferably, the three-phase composite powder of cesium tungsten bronze, rhenium trioxide and rhenium is obtained by introducing a cesium tungsten bronze-rhenium trioxide heterojunction into a traditional cesium tungsten bronze powder, aiming to utilize the strong localized surface plasmon resonance (LSPR) effect of rhenium trioxide to further enhance the NIR shielding ability of cesium tungsten bronze in the range of 800 nm to 1200 nm, and to enhance the light transmittance of the film in combination with the low absorption rate of rhenium trioxide in the visible light region.

[0028] Preferably, the three-phase composite powder of cesium tungsten bronze, rhenium trioxide and rhenium is obtained by introducing a trace amount of rhenium element locally reduced on the surface of the bulk phase into the traditional cesium tungsten bronze powder, aiming to improve the anti-aging performance and strength of the NIR shielding film by doping with rhenium element.

[0029] (3) Beneficial effects It is difficult to balance the absorption band and visible light transmittance when manufacturing traditional NIR absorbing materials. Although lowering the concentration of NIR absorbing materials can improve visible light transmittance, it will also reduce NIR absorption performance accordingly; conversely, although increasing the concentration of NIR absorbing materials can significantly improve NIR absorption performance, it will also greatly reduce visible light transmittance. You can't have both. In addition, doping solid particles in organic polymer films will cause the film to age faster, which will affect the product life to a certain extent.

[0030] Compared with the existing manufacturing methods of NIR absorption materials, this method achieves both NIR absorption performance and visible light transmittance. Its specific beneficial effects are detailed as follows: 1) The introduction of the cesium tungsten bronze-rhenium trioxide heterojunction causes the LSPR characteristic peak of the composite powder to redshift, enhancing the NIR shielding ability of the material while increasing the visible light transmittance of the powder; 2) The addition of rhenium element improves the strength of the film, enabling the film to significantly reduce its thickness while ensuring quality, reducing the average number of molecules in the cross-section, and further increasing the visible light transmittance. The composite powder is also stirred and melted with an organic polymer and then heated in an inert atmosphere, consolidating the uniformity of the film and avoiding the abnormal scattering of the film from affecting its performance; 3) Traditional materials such as cesium tungsten bronze often react with hydrogen radicals dissociated by ultraviolet radiation from organic materials, resulting in film discoloration. This method introduces a chemically stable rhenium element, which can inhibit the reaction of the composite powder with H*, effectively avoiding the discoloration of the film product. Description of the Drawings

[0031] Figure 1 The left and right small figures in the figure are schematic diagrams of the influence of film thickness on light transmittance before and after the introduction of rhenium element; Figure 2 XRD diffraction pattern of the composite powder in Example 1; Figure 3 Vis / UV spectra of the products with and without the introduction of rhenium element in Example 1; Figure 4 Energy spectrum scanning results of the composite powder in Example 1; Figure 5 Field emission high-resolution transmission electron microscope image of the composite powder in Example 1; Figure 6 On the left in the figure is the X-ray photoelectron spectrum (Re 4f) of the composite powder in Example 1; on the right is the X-ray photoelectron spectrum (Re 4f) of the powder without the introduction of rhenium element. Detailed Description of the Invention

[0032] To make the above features and advantages of the present invention more obvious and understandable, specific examples are given below for detailed description. Unless otherwise specified, the methods of the present invention are all conventional methods in the art.

[0033] Example 1 41.84 g of WO3 and 0.99 g of NH4ReO4 were placed in anhydrous ethanol and mechanically stirred at a rotation speed of 300 r / min for 30 min, and then evaporated to dryness at 70 o °C. The product was then placed in deionized water containing 10 g of Cs2CO3 and continued to be stirred at a rotation speed of 100 r / min at 95 oAt the temperature of C, mechanically stir until dried up, transfer the product to a high-energy ball mill and ball mill for 12 h at a rotation speed of 1000 rpm, and then at 600 o Heat the product in a 5% H2 / Ar mixed gas with a volume concentration at 600 C for 2 h to obtain a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium. Crush the cesium tungsten rhenium bronze solid with a high-speed shearer at a rotation speed of 5000 rpm for 35 min, then place it in a nano sand mill and grind it at a rotation speed of 1500 rpm for 2 h, and then place it in a centrifuge and centrifuge at 8000 r / min for 15 min. The average particle size of the obtained three-phase composite powder is 32 nm. Finally, transfer the composite powder into 100 ml of ultrapure water, add 0.5 g of Dispex A40 dispersant and 2 ml of propylene glycol methyl ether acetate for dispersion to obtain a three-phase composite slurry of cesium tungsten bronze, rhenium trioxide, and rhenium.

[0034] Take 3 g of polyethylene solid, ultrasonically clean it in ultrapure water for 8 min, then add it to 50 ml of ultrapure water, heat it to 130 C and stir until the solution is transparent, and then continue to stir at a speed of 300 r / min for 3 h. Place the film-forming raw material in a heating furnace and heat it at 90 C in a nitrogen atmosphere for 6 h. Weigh and add the three-phase composite slurry to the solution so that the mass concentration of cesium in the solution is 8 g / L, keep it at a constant temperature of 130 C, and stir magnetically for 6 h. Then, place it in an oven and heat it at a constant temperature of 130 C in a nitrogen atmosphere for 6 h. Finally, use a 25 µm Mayer rod to coat the product on the glass and place it in an oven filled with N2 and set the shape at 50 o C for 12 h. The obtained product film has a thickness of 250 µm. After being irradiated by a 250 W infrared lamp for 30 min, the temperature only rises to 47 C, with a haze of 29% and a light transmittance of 81%.

[0035] Example 2 Place 41.41 g of WO3 and 1.48 g of NH4ReO4 into absolute ethanol and mechanically stir at a rotation speed of 300 rpm for 30 min, and then evaporate to dryness at 70 o C. Then transfer the product into deionized water containing 10 g of Cs2CO3 and continue to stir mechanically at a rotation speed of 100 rpm at 95 o At the temperature of C, mechanically stir until dried up, transfer the product to a high-energy ball mill and ball mill for 12 h at a rotation speed of 1000 rpm, and then at 600 oHeat the product in a 5% H2 / Ar mixed gas with a volume concentration at C for 2 h to obtain a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium. Use a high-speed shearing machine to crush the cesium tungsten rhenium bronze solid at a speed of 5000 rpm for 35 min, then place it in a nano sand mill and grind it at a speed of 1500 rpm for 2 h, and then place it in a centrifuge and centrifuge it at 6000 r / min for 15 min. The average particle size of the obtained three-phase composite powder is 32 nm. Finally, transfer the composite powder into 100 ml of ultrapure water and add 0.5 g of Dispex A40 dispersant and 2 ml of propylene glycol methyl ether acetate for dispersion to obtain a three-phase composite slurry of cesium tungsten bronze, rhenium trioxide, and rhenium.

[0036] Take 6 g of solid polyvinyl alcohol, ultrasonically clean it in ultrapure water for 8 min and then add it to 80 ml of ultrapure water. Heat it to 95 °C and stir until the solution is transparent, and then continue to stir at a speed of 300 r / min for 3 h. Place the film-forming raw material in a heating furnace and heat it at 90 °C in a nitrogen atmosphere for 6 h. Weigh the three-phase composite slurry and add it to the solution so that the mass concentration in terms of cesium in the solution is 8 g / L, keep it at a constant temperature of 95 °C, and stir magnetically for 6 h. Then, place it in an oven and heat it at a constant temperature of 95 °C in a nitrogen atmosphere for 6 h. Finally, use a 30 µm Mayer rod to coat the product on the glass and place it in an oven filled with N2 and set the shape at 50 o C for 12 h. The obtained product film has a thickness of 310 µm and its temperature only rises to 51 °C after being irradiated by a 250 W infrared lamp for 30 min, with a haze of 29% and a light transmittance of 79%.

[0037] Example 3 Mix 42.70 g of WO3, 2.01 g of ReO2, and 8.66 g of Cs2O into a hydrothermal reaction solution (a solution with a volume ratio of water to ethanol of 2:1) in sequence, mechanically stir it at 50 °C for 30 min and place it in a muffle furnace. Starting from 180 °C, raise the temperature by 10 °C every 1 h, and after continuously raising the temperature for 6 h, keep it at 240 o C and keep it warm for 120 h. Then slowly cool it to room temperature in 6 h. Mechanically stir the product solution obtained by the hydrothermal method and evaporate it to dryness. The mechanical stirring should be strictly controlled at 150 r / min, and the evaporation temperature should be 120 °C. The average particle size of the obtained solid is 50 nm. Transfer it into 100 ml of ultrapure water and add 0.5 g of solsperese 5000 dispersant and 2 ml of propylene glycol methyl ether acetate for dispersion to obtain a three-phase composite slurry of cesium tungsten bronze, rhenium trioxide, and rhenium.

[0038] Take 3 g of polyvinyl butyral ester solid, ultrasonically clean it in ultrapure water for 8 min, then add it to 50 ml of ultrapure water, heat it to 180 °C and stir it until the solution is transparent, then continue stirring at 300 r / min for 3 h, and place the film-making raw materials in a heating furnace under a nitrogen atmosphere and heat them at 90 °C for 6 h. Weigh the three-phase composite slurry and add it to the solution so that the mass concentration of cesium in the solution is 8 g / L, keep the temperature at 130 °C, and stir it magnetically for 6 h. Then, place it in an oven under a nitrogen atmosphere and heat it at a constant temperature of 180 °C for 6 h. Finally, use a 35 µm Meyer rod to coat the product on glass and place it in an oven filled with N2 at 50 o C for 12 h.

[0039] The obtained product film thickness is 350 µm. After irradiation with 250 W infrared lamp for 30 min, the temperature only rises to 54 °C. It has a haze of 30% and a transmittance of 78%.

[0040] Comparative Case 1: Taking commercial cesium tungsten bronze NIR shielding film as a comparison, the commercial cesium tungsten bronze film has a haze of 37% and a transmittance of 71%. After being irradiated under a 250 W infrared lamp for 30 minutes, the temperature rises to 59 °C.

[0041] In summary, the three-phase composite powder of cesium tungsten bronze-rhenium trioxide-rhenium was successfully synthesized through solid-phase method and hydrothermal method and uniformly dispersed in the organic polymer transparent film. Experiments have proved that the double rhenium synergistically enhances the NIR shielding performance of the film. At the same time, the presence of trace rhenium element enhances the strength of the film and significantly reduces the thickness of the finished film, thereby improving the light transmittance of the film.

[0042] For those skilled in the art, various corresponding changes and modifications can be made according to the above technical solutions and concepts, and all of these changes and modifications should be included in the protection scope of the claims of the present invention.

Claims

1. A preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property, characterized in that: First, prepare a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium. After high-energy grinding, add it to an organic phase and make a thin film. The specific preparation method includes the following steps: (1)Prepare a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium using the solid-phase method or the hydrothermal method; among them, the solid-phase method includes: mixing a rhenium source, a tungsten source, and a cesium source according to a specific method and then evaporating to dryness, placing the product in a high-energy ball mill and ball milling at a rotation speed of 1000 rpm for 6 - 12 h, and then heating the ball-milled product in a 5% H2 / Ar mixed gas at 600 o °C for 2 h to obtain a three-phase composite powder of cesium tungsten bronze, rhenium trioxide, and rhenium; (2) Preparation of cesium tungsten rhenium bronze slurry: Use a high-speed shearer to crush the solid three-phase composite powder at a rotation speed of 5000 rpm for 15 - 35 min, then place it in a nano-grinder and grind it at a rotation speed of 1500 rpm for 30 - 120 min. Then place it in a centrifuge and centrifuge it at 5000 rpm - 8000 rpm for 3 min - 15 min. The particle size of the obtained powder is 15 nm - 35 nm. Finally, add water, a super-dispersant, and propylene glycol methyl ether acetate and disperse them to obtain a three-phase composite slurry of cesium tungsten bronze, rhenium trioxide, and rhenium; (3) Preparation of thin film raw materials: Weigh the organic polymer raw materials and add them to ultrapure water. Stir at 90 °C - 180 °C until the solution is clear and transparent, and then continue to stir at a speed of 300 r / min for 3 h. Place the obtained film-forming raw materials in a heating furnace, pass nitrogen, and heat at 90 °C for 6 h. Weigh the three-phase composite slurry and add it to the solution to make the mass-volume fraction of cesium in the solution 8 g / L and keep it at a constant temperature of 90 - 180 °C. Stir magnetically for 6 h. Then, place the finished product in an oven, pass nitrogen, and heat at a constant temperature of 90 - 180 °C for 6 h; (4) Preparation of NIR shielding thin film: Use a 25 - 35 µm Mayer rod to coat the thin film raw materials onto the glass, place them in an oven for shaping, and then cool to room temperature to obtain a high-transparency NIR shielding thin film with a visible light transmittance greater than 80%, a near-infrared light absorption rate greater than 90%, and a ultraviolet light absorption rate greater than 97%.

2. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, wherein: The hydrothermal method includes: mixing a rhenium source, a tungsten source and a cesium source according to the molar ratio of Cs to W+Re being x:1, where 0.166 < x < 0.33, mixing them by a specific method and adding them to a hydrothermal reaction solution. Under the condition of constant temperature at 50 °C, mechanical stirring is carried out to ensure sufficient mixing. Subsequently, the mixed solution is transferred to a reaction kettle, and the following heating scheme is adopted to ensure the completeness of the reaction: taking 180 °C as the starting temperature, then increasing the temperature by 10 °C per hour, continuously increasing the temperature for 6 h, and then keeping the temperature at 240 o °C for 120 h; After the heating process ends, slowly cool it for another 6 h to gradually return to room temperature; then evaporate the obtained product solution to dryness at a temperature of 120 °C - 140 °C. Grind the obtained solid with a quartz mortar and pass it through a 40-mesh sieve to finally obtain the three-phase composite powder.

3. The preparation method of a cesium tungsten bronze / double rhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 2, characterized in that: The hydrothermal reaction solution is a solution with a water-ethanol volume ratio of 2:

1.

4. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: The specific mixing method is to first place the tungsten source and the rhenium source into absolute ethanol and mechanically stir them at a rotation speed of 300 r / min for 30 min, and then evaporate to dryness at 70 o °C; then place the product and the cesium source together into deionized water and continue to mechanically stir them at a rotation speed of 100 r / min at a temperature of 95 o °C until evaporated to dryness.

5. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: The rhenium source is at least one of ReO4, Re2O7, Re2O5, ReO2, and NH4ReO4, and the cesium source is one of CsOH·H2O, Cs2CO3, Cs2O, Cs 11 O3, Cs4O, Cs7O, and Cs2O; the tungsten source is WO3.

6. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: The super-dispersant in step (2) is at least one of polyester-type super-dispersants, polyether-type super-dispersants, polyacrylate-type super-dispersants, polyolefin-type super-dispersants, oleic acid, isobutanol, and paraffin oil.

7. The preparation method of a cesium tungsten bronze / dirhenium co-enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: The organic polymer raw materials in step (3) are at least one of polyethylene, polyvinyl chloride, polyvinyl alcohol, and polyvinyl butyral.

8. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: The dosage ratio of the organic polymer raw materials to ultrapure water in step (3) is 3 g:50 ml.

9. The preparation method of a cesium tungsten bronze / dirhenium synergistically enhanced NIR shielding film with high light transmittance and anti-aging property according to claim 1, characterized in that: In step (4), the placement in the oven for shaping means placing the glass coated with the slurry into an oven filled with N2 and heating it at 50 o °C for 12 h to fix the film morphology.

10. A highly transparent and anti-aging cesium tungsten bronze / two-rhenium synergistically enhanced NIR shielding thin film prepared by the preparation method according to any one of claims 1 - 9.

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