Preparation method of military adaptive concealed radiation refrigeration material

Abstract

The invention belongs to the technical field of radiation refrigeration materials, and discloses a preparation method of a military self-adaptive hidden radiation refrigeration material in order to solve the problem that in the prior art, military equipment and facilities are difficult to meet the requirements for cooling capacity and concealment in the using process at the same time. Main components of the self-adaptive photochromic coating comprise a self-adaptive photochromic body, a high-molecular polymer and inorganic particles. By preparing the self-adaptive photochromic refrigeration material, light sources with different wave bands can be absorbed and converted in different light environments, the surface of the material presents a color similar to that of an ambient light source, and meanwhile, high solar reflectivity (greater than or equal to 90%) of the material is met, and sunlight is emitted to realize refrigeration. The self-adaptive photochromic radiation refrigeration material is wide in color coverage range, stable in color, capable of achieving switching among multiple colors, reversible, high in reflectivity in the sun wave band of 0.3-2.5 micrometers, high in emissivity in the atmosphere window wave band of 8-13 micrometers and capable of meeting the use requirements of self-adaptive concealment and radiation refrigeration at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of radiative cooling materials, and specifically to a preparation method of a military adaptive stealth radiative cooling material. Technical Background

[0002] Military equipment and facilities generate a large amount of heat during long-term outdoor use. Especially in high-temperature environments, excessive temperatures can easily lead to a decline in equipment performance or even failure. When soldiers wear equipment such as bulletproof vests and helmets for a long time, the body surface temperature may exceed 40 °C, causing heatstroke or heat exhaustion, which seriously affects the combat effectiveness of the military and the life and health of soldiers. Therefore, it is very necessary to adopt cooling technology to effectively cool military devices and equipment.

[0003] Radiative cooling technology can efficiently reflect sunlight in the wavelength range of 0.3 - 2.5 μm, and emit heat in the form of infrared through the atmospheric window wavelength range of 8 - 13 μm to outer space at absolute zero, achieving zero-energy spontaneous cooling, which helps to reduce the temperature of military devices and equipment. However, most of the current radiative cooling materials have a single white appearance color, lack combat stealth, are prone to target exposure, and the combat risk is increased. Patent CN112646427A discloses a double-layer light orange cooling coating, but this patent can only achieve a single color, cannot meet the requirement that the devices and equipment still have stealth during military transfers, and can only be used in a single scenario, with limitations in use. Therefore, it is necessary to explore a radiative cooling material that can adapt to various combat scenarios, meet both cooling and stealth requirements, effectively improve the combat efficiency of the military, and provide more comfortable and safe combat conditions for soldiers. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a military adaptive stealth radiative cooling material, and the material has the advantages of color adaptability to the ambient light source, a wide color coverage range, color stability, reversible color conversion, and excellent cooling performance.

[0005] To achieve the above purpose, the present solution provides a preparation method of a military adaptive stealth radiative cooling material, including the following steps: A preparation method of a military adaptive stealth radiative cooling material, characterized in that: 5 - 10% of an adaptive photochromic substance, 40 - 50% of a polymer, 25 - 35% of inorganic particles, and 10 - 20% of an organic solvent are mixed evenly, coated on the surface of a substrate, and after annealing treatment, a military adaptive stealth radiative cooling material is obtained.

[0006] Further, the preparation process of the adaptive photochromic substance includes the following steps:

[0007] (1) 1-Phenyl-3-trifluoromethyl-1H-pyrazol-5(4H)-one and 4-dimethylaminobenzaldehyde were added to absolute ethanol in a mass ratio of 2:1:15, heated to 90 °C and reacted for 5 hours, filtered and dried at room temperature for 12 hours to obtain dyeing product 1.

[0008] (2) 1,3-Dimethylbarbituric acid and 4-dimethylaminobenzaldehyde were added to absolute ethanol in a mass ratio of 1:1:18, reacted for 5 hours, filtered and dried at room temperature for 12 hours to obtain dyeing product 2.

[0009] (3) 1-Phenyl-3-trifluoromethyl-1H-pyrazol-5(4H)-one and 2-furaldehyde were added to dichloromethane in a mass ratio of 2:1:40, reacted at a rotation speed of 200 r / min and a temperature of 40 °C for 3 hours, the solution was evaporated by vacuum rotary evaporation, the obtained solid was dissolved in methanol, and indoline was slowly added in a mass ratio of 5:30:2, filtered and dried at room temperature for 12 hours to obtain a photochromic product.

[0010] (4) The dyeing molecular product 1 or 2 and the photochromic product were mixed in a mass ratio of 1:1, and an adaptive photochromic body was prepared by a planetary stirrer with a revolution speed of 200 r / min and a rotation speed of 500 r / min after being stirred and mixed evenly.

[0011] Furthermore, the high molecular polymer is any one of polyvinyl chloride, polycaprolactone and polyurethane.

[0012] Furthermore, the inorganic particles are any one or more of silicon dioxide, alumina and zirconia, and the particle size is 5-50 μm.

[0013] Furthermore, the organic solvent is any one of tetrahydrofuran, acetone and dichloromethane or a mixed solution of any two of them.

[0014] Furthermore, the preparation of military adaptive stealth radiation cooling materials includes the following specific steps:

[0015] (1) The high molecular polymer was added to the organic solvent, and stirred at a rotation speed of 300 r / min and a temperature of 40 °C for 2 hours.

[0016] (2) Inorganic particles were added, and stirred at a rotation speed of 500 r / min and a temperature of 40 °C for 12 hours.

[0017] (3) The adaptive photochromic body was added, and stirred at a rotation speed of 300 r / min and a temperature of 40 °C for 2 hours.

[0018] (4) The mixed solution was coated on the surface of the substrate and annealed at 70-100 °C for 30 minutes to obtain military adaptive stealth radiation cooling materials.

[0019] Furthermore, the coating method of the military adaptive stealth radiative cooling material is any one of spraying, brushing, scraping, and spin coating.

[0020] Furthermore, the solar emissivity of the military adaptive stealth radiative cooling material is greater than 90%, and the emissivity in the atmospheric window is greater than 90%.

[0021] The adaptive stealth radiative cooling material provided by the present invention can be applied in the fields of military buildings, tents, clothing, and transportation.

[0022] A preparation method of a military adaptive stealth radiative cooling material provided by the present invention has at least the following beneficial effects compared with the prior art:

[0023] In the present invention, the radiative cooling material has an adaptive color-changing function, the surface color can be reversibly changed according to different light sources in the environment, the color is stable, it can adapt to different scenarios, and it has a high solar reflectivity (≥90%) and an emissivity in the atmospheric window (≥90%), meeting the cooling and stealth requirements of the military for military devices and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the solar reflectivity diagram of the military adaptive stealth radiative cooling material in Specific Embodiment 1 of the present invention;

[0025] Figure 2 is the emissivity diagram of the military adaptive stealth radiative cooling material in Specific Embodiment 1 of the present invention;

[0026] Figure 3 is the adaptive appearance diagram of the military adaptive stealth radiative cooling material in a green environment in Specific Embodiment 1 of the present invention;

[0027] Figure 4 is the solar reflectivity diagram of the military adaptive stealth radiative cooling material in Specific Embodiment 2 of the present invention;

[0028] Figure 5 is the emissivity diagram of the military adaptive stealth radiative cooling material in Specific Embodiment 2 of the present invention;

[0029] Figure 6 is the adaptive appearance diagram of the military adaptive stealth radiative cooling material in a yellow environment in Specific Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Specific Embodiment 1:

[0032] Dissolve 6 g of 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one and 3 g of 4-dimethylaminobenzaldehyde in 45 mL of absolute ethanol, heat to 90 °C and react for 5 hours, filter and dry at 30 °C for 12 hours to obtain the dyeing product 1.

[0033] Dissolve 6 g of 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one and 3 g of 2-furaldehyde in 120 mL of dichloromethane, heat the reaction to 40 °C, stir at a rotation speed of 200 r / min, react for 3 hours, and rotary evaporate the solution under vacuum to obtain a dry solid. Weigh 5 g of the solid and dissolve it with 3 g of indoline in 30 mL of methanol, filter and dry the product at room temperature for 12 hours to obtain the photochromic product.

[0034] Add 4 g of the dyeing molecular product 1 and 4 g of the photochromic product to a planetary stirrer, set the revolution speed to 200 r / min and the rotation speed to 500 r / min, stir for 4 hours, and prepare the self-adaptive photochromic body after stirring and mixing evenly.

[0035] Add 25 g of polycaprolactone to 5 g of dichloromethane, stir at a rotation speed of 300 r / min and a temperature of 40 °C for 2 hours; then add 15 g of silica, stir at a rotation speed of 500 r / min and a temperature of 40 °C for 12 hours; then add the self-adaptive photochromic body, stir at a rotation speed of 300 r / min and a temperature of 40 °C for 2 hours; finally, brush the mixed solution on the surface of a glass substrate and anneal at 70 °C for 30 minutes to obtain a military self-adaptive stealth radiative cooling material. Its solar reflectance is as Figure 1 shown, and its emissivity is as Figure 2 shown, and its environmental self-adaptive appearance is as Figure 3 shown. Specific Example 2:

[0037] Add 5 g of 1,3-dimethylbarbituric acid and 5 g of 4-dimethylaminobenzaldehyde to 90 mL of absolute ethanol, react for 5 hours, filter and dry at room temperature for 12 hours to obtain the dyeing product 2.

[0038] Dissolve 6 g of 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one and 3 g of 2-furaldehyde in 120 mL of dichloromethane, heat the reaction to 40 °C, stir at a rotation speed of 200 r / min, react for 3 hours, and rotary evaporate the solution under vacuum to obtain a dry solid. Weigh 5 g of the solid and dissolve it with 3 g of indoline in 30 mL of methanol, filter and dry the product at room temperature for 12 hours to obtain the photochromic product.

[0039] Add 4 g of the dyeing molecular product 1 and 4 g of the photochromic product to a planetary stirrer. Set the revolution speed to 200 r / min, the rotation speed to 500 r / min, and the stirring duration to 4 hours. After stirring and mixing evenly, an adaptive photochromic body is prepared.

[0040] Add 25 g of polyvinyl chloride to 5 g of acetone. Stir at a speed of 300 r / min and a temperature of 40 °C for 2 hours; then add 15 g of silica and stir at a speed of 500 r / min and a temperature of 40 °C for 12 hours; then add the adaptive photochromic body and stir at a speed of 300 r / min and a temperature of 40 °C for 2 hours; finally, scrape the mixed solution onto the surface of a glass substrate and anneal at 100 °C for 30 minutes to obtain a military adaptive stealth radiative cooling material. Its solar reflectance is as Figure 4 shown, and its emissivity is as Figure 5 shown, and its appearance in environmental adaptation is as Figure 6 shown.

[0041] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Without departing from the principle of the present invention, modifications and improvements made to the technical solutions recorded in the above specific embodiments are all regarded as the protection scope of the present invention.

Claims

1. A method for preparing a military adaptive concealed radiation refrigeration material, characterized in that: 5-10% of adaptive photochromic body, 40-50% of high molecular polymer, 25-35% of inorganic particles and 10-20% of organic solvent are uniformly mixed, coated on the surface of substrate, and annealed to obtain military adaptive concealed radiation refrigeration material.

2. The method for preparing a military adaptive concealed radiation refrigeration material according to claim 1, characterized in that: The preparation process of the adaptive photochromic body includes the following steps: (1) 1-phenyl-3-trifluoromethyl-1H-pyrazol-5(4H)one and 4-dimethylaminobenzaldehyde were added to anhydrous ethanol at a mass ratio of 2:1:15, heated to 90°C for reaction for 5 hours, filtered and dried at room temperature for 12 hours to obtain a dyeing product 1. (2) 1,3-dimethylbarbituric acid and 4-dimethylaminobenzaldehyde were added to anhydrous ethanol at a mass ratio of 1:1:18, reacted for 5 hours, filtered and dried at room temperature for 12 hours to obtain a dyeing product 2. (3) 1-phenyl-3-trifluoromethyl-1H-pyrazol-5(4H)one and 2-furancarboxaldehyde were added to dichloromethane in a mass ratio of 2:1:40, and reacted at a speed of 200 r / min and a temperature of 40°C for 3 hours. The solution was evaporated in a vacuum rotary evaporator, and the obtained solid was dissolved in methanol. Indoline was slowly added in a mass ratio of 5:30:2, filtered and dried at room temperature for 12 hours to obtain a photochromic product. (4) The dyeing molecule product 1 or 2 and the photochromic product are mixed in a mass ratio of 1:1, passed through a planetary stirrer, and have an orbital speed of 200 r / min and an autorotational speed of 500 r / min for 4 hours. After the mixture is evenly mixed, an adaptive photochromic body is prepared.

3. The method for preparing a military adaptive concealed radiation refrigeration material according to claim 1, characterized in that: The high molecular polymer is any one of polyvinyl chloride, polycaprolactone and polyurethane.

4. The method for preparing a military adaptive concealed radiation refrigeration material according to claim 1, characterized in that: The inorganic particles are any one or more of silicon dioxide, aluminum oxide, and zirconium oxide, and the particle size is 5-50 μm.

5. The method for preparing a military adaptive concealed radiation refrigeration material according to claim 1, characterized in that: The organic solvent is any one of tetrahydrofuran, acetone and dichloromethane or a mixed solution of any two of them.

6. The method for preparing a military adaptive concealed radiation refrigeration material according to claims 1-5, characterized in that: The specific steps include: (1) Add the high molecular weight polymer into the organic solvent and stir at a speed of 300 r / min and a temperature of 40°C for 2 hours. (2) Inorganic particles were added and stirred at a rotation speed of 500 r / min and a temperature of 40° C. for 12 hours. (3) Add the adaptive photochromic body and stir at a speed of 300 r / min and a temperature of 40° C. for 2 hours. (4) coating the mixed solution on the surface of the substrate, and annealing the mixed solution at 70-100° C. for 30 minutes to obtain a military self-adaptive concealed radiation refrigeration material.

7. The military adaptive concealed radiation refrigeration material according to claims 1-6, characterized in that: The coating method for preparing the military adaptive concealed radiation refrigeration material is any one of spraying, brushing, scraping and spin coating.

8. The military adaptive concealed radiation refrigeration material according to claims 1-7, characterized in that: The military self-adaptive concealed radiation refrigeration material has a solar emissivity greater than 90%, and an emissivity at the atmospheric window greater than 90%.

9. Use of a military adaptive concealed radiation refrigeration material according to any one of claims 1 to 8 in the fields of military buildings, tents, clothing, and transportation.

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