Radiation cooling fabric and method of making the same

Abstract

The application provides a preparation method of a radiation refrigeration fabric, and the preparation method comprises the following steps: S1, performing hydrophilic treatment on a fabric surface to obtain a fabric layer; S2, adding Ag-TiO2@BaSO4 into water-based polyurethane, stirring at 800-1000 r / min for 10-30 min, uniformly mixing the Ag-TiO2@BaSO4 and the water-based polyurethane, coating the mixture on the hydrophilic treated fabric layer, and then pre-drying at 100-110 DEG C for 1-3 min and baking at 130-155 DEG C for 2-5 min to obtain the radiation refrigeration fabric. The radiation refrigeration fabric is coated with Ag-TiO2@BaSO4 on the fabric surface to achieve the refrigeration purpose, BaSO4 is used as a hollow core layer in the Ag-TiO2@BaSO4, TiO2 is used as a shell layer, and nano Ag particles are inlaid on the TiO2, and the synergistic effect of the three achieves the radiation refrigeration function.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional fabrics, in particular to a radiative cooling fabric and a preparation method thereof. BACKGROUND

[0002] Under the sunlight, objects will accumulate a lot of heat, causing the surface and internal temperature to rise, which brings many inconveniences and hazards to people's activities. Radiative cooling technology transmits the heat of the heat source to the outer space cold source through the atmospheric window by infrared radiation, thereby inhibiting the rise of the surface temperature of the coating and reducing the internal temperature of the coated object, providing a comfortable working and living environment for the user.

[0003] However, ordinary fabrics lack efficient temperature regulation mechanisms and are difficult to cope with drastic changes in environmental temperature, especially how to effectively cool in a high-temperature environment, which is a difficult problem that needs to be solved for cooling fabrics at present. From the existing work, the current cooling fabric mainly develops from three ways of convection, conduction and wet state evaporation. For example, heat-conducting materials such as carbon nanotubes, graphene, boron nitride, etc. are used as coatings or embedded into the fiber structure to prepare heat-conducting cool textiles; the fiber cross-sectional structure is designed or the fabric finishing method is used to improve the moisture absorption and water conductivity of the fabric to accelerate the evaporation of human sweat to achieve the effect of heat dissipation; in addition, other technologies such as adding phase change materials to the coating or fiber structure can absorb and store human heat to achieve cooling by using the characteristics of phase change materials; active cooling clothes with air and liquid cooling systems are also used for human heat management. In recent years, passive cooling fabrics based on radiative heat regulation have attracted widespread attention due to their non-energy consumption. SUMMARY

[0004] The technical problem to be solved is to provide a radiative cooling fabric, which is coated with Ag-TiO2@BaSO4 on the surface of the fabric to achieve the purpose of cooling. In Ag-TiO2@BaSO4, BaSO4 is the hollow core layer, TiO2 is the shell layer, and nano Ag particles are embedded on TiO2, which realizes the function of radiative cooling through the synergistic effect of the three.

[0005] The technical scheme is a radiative cooling fabric, which comprises a fabric layer and a coating layer, and the coating layer is composed of water-based polyurethane and Ag-TiO2@BaSO4. In Ag-TiO2@BaSO4, BaSO4 is the hollow core layer, TiO2 is the shell layer, and nano Ag particles are embedded on TiO2.

[0006] The preparation method of the above-mentioned radiative cooling fabric comprises the following steps:

[0007] S1. The surface of the fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0008] S2. Add Ag-TiO2@BaSO4 into the aqueous polyurethane, stir at 800-1000 r / min for 10-30 min to mix Ag-TiO2@BaSO4 and the aqueous polyurethane uniformly, coat on the hydrophilic treated fabric layer, then pre-dry at 100-110℃ for 1-3 min, and bake at 130-155℃ for 2-5 min to obtain the radiation refrigeration fabric.

[0009] Preferably, the fabric is any one of natural fiber cotton, synthetic fiber fabric or regenerated fiber fabric.

[0010] Preferably, the content of Ag-TiO2@BaSO4 in the aqueous polyurethane is 5-8 wt%.

[0011] Preferably, the preparation method of Ag-TiO2@BaSO4 comprises the following steps:

[0012] S11. After ball milling, the calcium carbonate is added into water and ultrasonically dispersed to obtain a calcium carbonate suspension;

[0013] S12. Barium chloride is added into the ethylenediaminetetraacetic acid disodium salt-ammonia solution, and after uniform mixing and stirring, the pH value is adjusted to neutral, then the solution is added dropwise into the calcium carbonate suspension prepared in step S11, and after uniform mixing and stirring, sodium sulfate aqueous solution is added dropwise, and stirring reaction is performed to deposit barium sulfate on the surface of the calcium carbonate, and after drying, heat treatment is performed, after the heat treatment, dilute hydrochloric acid solution is added to remove the decomposed calcium oxide, and deposition, drying are performed again to obtain hollow barium sulfate;

[0014] S13. The hollow barium sulfate is ultrasonically dispersed into anhydrous ethanol, ammonia water is added, and then tetrabutyl titanate is added, and the mixture is continuously stirred under water bath, and then centrifuged, washed and dried to obtain TiO2@BaSO4;

[0015] S14. The silver nitrate solution and the tannic acid solution are mixed and stirred, and then sodium borohydride solution is rapidly added dropwise under vigorous stirring to obtain a nano-silver sol;

[0016] S15. TiO2@BaSO4 is first added into the nano-silver sol and stirred uniformly, then the tetrabutyl titanate ethanol solution is added dropwise into the nano-silver sol, after the addition is completed, nitric acid is added dropwise, stirring reaction is performed, and then normal temperature aging is performed, and then the obtained powder is reacted at high temperature under nitrogen protection to finally obtain Ag-TiO2@BaSO4.

[0017] Preferably, the concentration of the calcium carbonate suspension in step S11 is 2-6 wt%.

[0018] Preferably, the molar ratio of barium chloride, sodium sulfate and calcium carbonate in step S12 is 10:10:0.5-2, the temperature of heat treatment is 800-1000℃, and the time is 0.5-1.5h.

[0019] Preferably, the mass-volume ratio of hollow barium sulfate, ammonia and tetrabutyl titanate in step S13 is 0.2-0.4g:0.1-0.3mL:0.3-0.5mL, the concentration of hollow barium sulfate in ethanol is 3-5wt%, the water bath temperature is 40-45℃, and the stirring time is 10-15h.

[0020] Preferably, the molar ratio of silver nitrate, tannic acid and sodium borohydride in step S14 is 20-30:4-6:1-3.

[0021] Preferably, the stirring temperature in step S15 is 60-75℃, the time is 3-5h, the room temperature aging time is 40-60h, the high temperature reaction temperature is 500-600℃, and the time is 2-4h.

[0022] Beneficial effects: The radiation cooling fabric of the present application has the following advantages:

[0023] 1. The surface of the fabric after finishing is covered with a layer of hollow coating particles, and these hollow structures can enhance the scattering of sunlight to reduce heat absorption.

[0024] 2. Titanium dioxide is coated on hollow barium sulfate, and the two components are used together to combine the advantages of both and achieve more efficient radiation cooling effect. The scattering effect of titanium dioxide can further reduce the solar energy absorbed by the material, while the high infrared emissivity of barium sulfate ensures that the material can effectively release internal heat in the form of infrared radiation to the environment, suitable for application in various environments.

[0025] 3. The hollow structure in the present application can provide additional thermal insulation effect, reduce the heat transfer inside the material, and further improve the efficiency of radiation cooling. The coating of titanium dioxide may be to improve the optical performance of the material, such as enhancing the scattering effect, or to provide better chemical stability and durability.

[0026] 4. In the present application, silver nanoparticles are embedded in TiO2, and the SPR effect of silver particles can enhance the light absorption of the material in the visible and near-infrared regions, which helps to improve the reflectivity of the material to this part of the solar spectrum, thereby improving the efficiency of radiation cooling. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with examples, and the following examples are an explanation of the present application and the present application is not limited to the following examples:

[0028] Example 1

[0029] A preparation method of a radiation refrigeration fabric, the preparation method comprising the following steps:

[0030] S1. Hydrophilic treatment is performed on one surface of a polyester fabric to obtain a fabric layer;

[0031] S2. Ag-TiO2@BaSO4 is added to the aqueous polyurethane, the content of Ag-TiO2@BaSO4 in the aqueous polyurethane is 5wt%, stirring at 800r / min for 30min, so that Ag-TiO2@BaSO4 is uniformly mixed with the aqueous polyurethane, and then coated on the hydrophilic treated fabric layer, and then pre-dried at 110℃ for 1min and baked at 155℃ for 2min to obtain the radiation refrigeration fabric;

[0032] The preparation method of the Ag-TiO2@BaSO4 comprises the following steps:

[0033] S11. After ball milling, the calcium carbonate is added to water, and ultrasonic dispersion is performed to obtain a calcium carbonate suspension with a concentration of 2wt%;

[0034] S12. Barium chloride is added to an aqueous ammonia solution of disodium ethylenediaminetetraacetate, and after uniform mixing and stirring, the pH value is adjusted to neutral, and then the solution is added dropwise to the calcium carbonate suspension prepared in step S11, and after uniform stirring and mixing, sodium sulfate aqueous solution is added dropwise, the molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:0.5, stirring and reaction, depositing barium sulfate on the surface of calcium carbonate, drying and then heat treatment, the heat treatment temperature is 1000℃, the time is 0.5h, after heat treatment, adding dilute hydrochloric acid solution to remove the decomposed calcium oxide, and then depositing, drying again to obtain hollow barium sulfate;

[0035] S13. Hollow barium sulfate is ultrasonically dispersed into anhydrous ethanol, the concentration of hollow barium sulfate in ethanol is 5wt%, ammonia water is added, and then tetrabutyl titanate is added, the mass-volume ratio of hollow barium sulfate, ammonia water and tetrabutyl titanate is 0.2g:0.1mL:0.3mL, constant stirring under water bath, the water bath temperature is 45℃, the stirring time is 10h, centrifugal washing and drying to obtain TiO2@BaSO4; S14. Silver nitrate solution and tannic acid solution are mixed and stirred, and then sodium borohydride solution is rapidly added dropwise under vigorous stirring to react, the molar ratio of silver nitrate, tannic acid and sodium borohydride is 20:4:1, to obtain a nano-silver sol;

[0036] S15. First, the TiO2@BaSO4 is added to the nano-silver sol and stirred until uniform. Then, the tetrabutyl titanate ethanol solution is added dropwise to the nano-silver sol. After the dropwise addition is completed, nitric acid is added dropwise. The stirring reaction is carried out at a temperature of 60℃ for 5h. Subsequently, the obtained powder is aged at room temperature for 40h. Then, the powder is subjected to high-temperature reaction under nitrogen protection at a temperature of 500℃ for 4h. Finally, the Ag-TiO2@BaSO4 is obtained.

[0037] Example 2

[0038] A preparation method of a radiation cooling fabric, the preparation method comprising the following steps:

[0039] S1. A surface of a polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer.

[0040] S2. The Ag-TiO2@BaSO4 is added to the aqueous polyurethane, and the content of the Ag-TiO2@BaSO4 in the aqueous polyurethane is 8wt%. The Ag-TiO2@BaSO4 is stirred at 1000r / min for 10min to mix the Ag-TiO2@BaSO4 and the aqueous polyurethane uniformly. The mixture is coated on the hydrophilic treated fabric layer, and then pre-baked at 100℃ for 3min and baked at 130℃ for 5min to obtain the radiation cooling fabric.

[0041] The preparation method of the Ag-TiO2@BaSO4 comprises the following steps:

[0042] S11. The calcium carbonate is ground and then added to water to obtain a calcium carbonate suspension with a concentration of 6wt%.

[0043] S12. The barium chloride is added to the ethylenediaminetetraacetic acid disodium salt-ammonia solution, and then stirred and mixed uniformly. The pH value is adjusted to neutral. Then, the solution is added dropwise to the calcium carbonate suspension prepared in step S11. After stirring and mixing uniformly, the sodium sulfate aqueous solution is added dropwise. The molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:2. The stirring reaction is carried out to deposit barium sulfate on the surface of the calcium carbonate. After drying, the thermal treatment is carried out at a temperature of 800℃ for 1.5h. After the thermal treatment, the dilute hydrochloric acid solution is added to remove the decomposed calcium oxide. The deposition, drying and obtaining of the hollow barium sulfate are carried out again.

[0044] S13. Hollow barium sulfate is taken and dispersed into anhydrous ethanol, the concentration of hollow barium sulfate in ethanol is 3wt%, ammonia water is added, then tetrabutyl titanate is added, the mass-volume ratio of hollow barium sulfate, ammonia water and tetrabutyl titanate is 0.4g:0.3mL:0.5mL, the stirring is continued under water bath, the water bath temperature is 40℃, the stirring time is 15h, TiO2@BaSO4 is obtained by centrifugal washing and drying; S14. Silver nitrate solution and tannic acid solution are mixed and stirred, then sodium borohydride solution is rapidly added under the condition of vigorous stirring, the molar ratio of silver nitrate, tannic acid and sodium borohydride is 30:6:3, and nano-silver sol is obtained;

[0045] S15. TiO2@BaSO4 is first added into the nano-silver sol and stirred uniformly, then tetrabutyl titanate ethanol solution is added into the nano-silver sol, nitric acid is added after the addition is completed, stirring reaction is carried out, the stirring temperature is 75℃, the time is 3h, aging at room temperature is carried out, the time of aging at room temperature is 60h, then the obtained powder is subjected to high temperature reaction under nitrogen protection, the temperature of high temperature reaction is 600℃, the time is 2h, and finally Ag-TiO2@BaSO4 is obtained.

[0046] Example 3

[0047] A preparation method of a radiation refrigeration fabric, the preparation method comprising the following steps:

[0048] S1. One surface of a polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0049] S2. Ag-TiO2@BaSO4 is added into aqueous polyurethane, the content of Ag-TiO2@BaSO4 in aqueous polyurethane is 6wt%, stirring is carried out at 950r / min for 15min, Ag-TiO2@BaSO4 is uniformly mixed with aqueous polyurethane, is coated on the hydrophilic treated fabric layer, then pre-drying is carried out at 100℃ for 3min, and baking is carried out at 135℃ for 4min, and a radiation refrigeration fabric is prepared;

[0050] The preparation method of the Ag-TiO2@BaSO4 comprises the following steps:

[0051] S11. After calcium carbonate is ball milled, it is added into water and uniformly dispersed by ultrasonic to obtain a calcium carbonate suspension with a concentration of 3wt%;

[0052] S12. Barium chloride was added to the ethylenediaminetetraacetic acid disodium salt-ammonia solution, and after uniform mixing and stirring, the pH value was adjusted to neutral. Then the solution was added dropwise to the calcium carbonate suspension prepared in step S11, and after uniform mixing and stirring, sodium sulfate aqueous solution was added dropwise. The molar ratio of barium chloride, sodium sulfate and calcium carbonate was 10:10:0.8. After stirring and reaction, barium sulfate was deposited on the surface of calcium carbonate. After drying, heat treatment was performed at a temperature of 950 DEG C for 0.5 h. After heat treatment, dilute hydrochloric acid solution was added to remove the decomposed calcium oxide. After deposition, drying was performed again to obtain hollow barium sulfate;

[0053] S13. Hollow barium sulfate was ultrasonically dispersed in anhydrous ethanol. The concentration of hollow barium sulfate in ethanol was 3.5 wt%. Ammonia water was added, and then tetrabutyl titanate was added. The mass-volume ratio of hollow barium sulfate, ammonia water and tetrabutyl titanate was 0.3 g:0.2 mL:0.3 mL. After continuous stirring in a water bath, the water bath temperature was 45 DEG C, and the stirring time was 10 h. After centrifugal washing and drying, TiO2@BaSO4 was obtained.

[0054] S15. TiO2@BaSO4 was first added to the nano-silver sol and stirred uniformly. Then tetrabutyl titanate ethanol solution was added dropwise to the nano-silver sol. After the addition was completed, nitric acid was added dropwise. After stirring and reaction at a temperature of 65 DEG C for 3 h, aging at room temperature was performed for 45 h. Subsequently, the obtained powder was subjected to high-temperature reaction under nitrogen protection at a temperature of 550 DEG C for 4 h. Finally, Ag-TiO2@BaSO4 was obtained.

[0055] Example 4

[0056] A preparation method of a radiation cooling fabric, the preparation method comprising the following steps:

[0057] S1. One surface of a polyester fabric was subjected to hydrophilic treatment to obtain a fabric layer.

[0058] S2. Ag-TiO2@BaSO4 was added to water-based polyurethane. The content of Ag-TiO2@BaSO4 in the water-based polyurethane was 7 wt%. After stirring at 850 r / min for 25 min, Ag-TiO2@BaSO4 was uniformly mixed with the water-based polyurethane. The mixture was coated on the hydrophilic treated fabric layer, and then pre-dried at 110 DEG C for 1 min and baked at 150 DEG C for 3 min to obtain a radiation cooling fabric.

[0059] The preparation method of Ag-TiO2@BaSO4 comprises the following steps:

[0060] S11. After ball milling the calcium carbonate, it is added to water, ultrasonically dispersed to obtain a calcium carbonate suspension with a concentration of 5wt%;

[0061] S12. Barium chloride is added to the ethylenediaminetetraacetic acid disodium salt-ammonia solution, and after uniform mixing and stirring, the pH value is adjusted to neutral. Then the solution is added dropwise to the calcium carbonate suspension prepared in step S11, and after uniform mixing and stirring, sodium sulfate aqueous solution is added dropwise. The molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:1.5. After stirring and reaction, barium sulfate is deposited on the surface of calcium carbonate. After drying, heat treatment is performed at a temperature of 850℃ for 1.5h. After heat treatment, dilute hydrochloric acid solution is added to remove the decomposed calcium oxide. Deposition, drying and hollow barium sulfate are obtained again;

[0062] S13. Hollow barium sulfate is ultrasonically dispersed in anhydrous ethanol with a concentration of 4.5wt%. Ammonia water and tetrabutyl titanate are added. The mass-volume ratio of hollow barium sulfate, ammonia water and tetrabutyl titanate is 0.4g:0.3mL:0.5mL. After constant stirring in a water bath, the water bath temperature is 40℃ and the stirring time is 15h. After centrifugal washing and drying, TiO2@BaSO4 is obtained;

[0063] S15. TiO2@BaSO4 is first added to the nanosilver sol and stirred uniformly. Then tetrabutyl titanate ethanol solution is added dropwise to the nanosilver sol. After the dropwise addition is completed, nitric acid is added dropwise. After stirring and reaction at a temperature of 70℃ for 4h, aging at room temperature is performed for 55h. Subsequently, the obtained powder is subjected to high-temperature reaction under nitrogen protection at a temperature of 600℃ for 4h. Finally, Ag-TiO2@BaSO4 is obtained.

[0064] Example 5

[0065] A preparation method of a radiation cooling fabric, the preparation method comprising the following steps:

[0066] S1. One surface of the polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0067] S2. The Ag-TiO2@BaSO4 is added to the aqueous polyurethane, and the content of the Ag-TiO2@BaSO4 in the aqueous polyurethane is 6.6wt%, and the Ag-TiO2@BaSO4 is stirred at 900r / min for 20min to mix the Ag-TiO2@BaSO4 and the aqueous polyurethane uniformly, and then the mixture is coated on the hydrophilic treated fabric layer, and then the mixture is pre-dried at 105℃ for 2min and baked at 140℃ for 4min to obtain the radiation refrigeration fabric;

[0068] The preparation method of the Ag-TiO2@BaSO4 comprises the following steps:

[0069] S11. After the calcium carbonate is ball milled, the calcium carbonate is added to water and ultrasonically dispersed to obtain a calcium carbonate suspension with a concentration of 5.5wt%;

[0070] S12. The barium chloride is added to the ethylenediaminetetraacetic acid disodium salt-ammonia solution, and after being uniformly mixed and stirred, the pH value is adjusted to neutral, and then the solution is added dropwise to the calcium carbonate suspension prepared in step S11, and after being uniformly mixed and stirred, the sodium sulfate aqueous solution is added dropwise, the molar ratio of the barium chloride, the sodium sulfate and the calcium carbonate is 10:10:1, and the stirring reaction is performed, the barium sulfate is deposited on the surface of the calcium carbonate, and after being dried, the heat treatment is performed, the heat treatment temperature is 900℃, and the heat treatment time is 1h, and then the dilute hydrochloric acid solution is added to remove the decomposed calcium oxide, and the deposition, drying are performed again to obtain the hollow barium sulfate;

[0071] S13. The hollow barium sulfate is ultrasonically dispersed into anhydrous ethanol, the concentration of the hollow barium sulfate in the ethanol is 4wt%, the ammonia water is added, and then the tetrabutyl titanate is added, the mass-volume ratio of the hollow barium sulfate, the ammonia water and the tetrabutyl titanate is 0.35g:0.25mL:0.4mL, the continuous stirring is performed under water bath, the water bath temperature is 40℃, the stirring time is 15h, and then the TiO2@BaSO4 is obtained by centrifugal washing and drying;

[0072] S15. The TiO2@BaSO4 is first added to the nanosilver sol and stirred uniformly, then the tetrabutyl titanate ethanol solution is added dropwise to the nanosilver sol, after the dropwise addition is completed, the nitric acid is added dropwise, the stirring reaction is performed, the stirring temperature is 70℃, the time is 4h, the normal temperature aging is performed, the normal temperature aging time is 40h, then the obtained powder is subjected to high temperature reaction under nitrogen protection, the high temperature reaction temperature is 600℃, and the high temperature reaction time is 4h, and finally the Ag-TiO2@BaSO4 is obtained.

[0073] Comparative Example 1

[0074] A preparation method of a radiation refrigeration fabric, the preparation method comprising the following steps:

[0075] S1. One surface of the polyester fabric is treated to be hydrophilic to obtain a fabric layer;

[0076] S2. Ag-TiO2@BaSO4 is added to the aqueous polyurethane, the content of Ag-TiO2@BaSO4 in the aqueous polyurethane is 6.6wt%, and the Ag-TiO2@BaSO4 is mixed uniformly with the aqueous polyurethane at 900r / min for 20min, and then coated on the hydrophilic treated fabric layer, and then pre-dried at 105℃ for 2min and baked at 140℃ for 4min to obtain a radiation refrigeration fabric;

[0077] The preparation method of the Ag-TiO2@BaSO4 comprises the following steps:

[0078] S11. After the calcium carbonate is ball milled, it is added to water and ultrasonically dispersed to obtain a calcium carbonate suspension with a concentration of 5.5wt%;

[0079] S12. Barium chloride is added to an ethylenediaminetetraacetic acid disodium salt-ammonia solution, and after uniform mixing and stirring, the pH value is adjusted to neutral, then the solution is added dropwise to the calcium carbonate suspension prepared in step S11, and after uniform mixing and stirring, sodium sulfate solution is added dropwise, the molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:1, and stirring reaction is carried out to deposit barium sulfate on the surface of calcium carbonate, and after drying, deposition and drying are carried out again to obtain barium sulfate coated calcium carbonate;

[0080] S13. The barium sulfate coated calcium carbonate is ultrasonically dispersed in anhydrous ethanol, the concentration of the barium sulfate coated calcium carbonate in the ethanol is 4wt%, ammonia water is added, then tetrabutyl titanate is added, the mass-volume ratio of ammonia water, tetrabutyl titanate and hollow barium sulfate is 0.35g:0.25mL:0.4mL, and the mixture is continuously stirred under water bath heating, the water bath temperature is 40℃, and the stirring time is 15h, then TiO2@BaSO4 is obtained after centrifugal washing and drying;

[0081] S14. Silver nitrate solution and tannic acid solution are mixed and stirred, then sodium borohydride solution is rapidly added dropwise under vigorous stirring to react, the molar ratio of silver nitrate, tannic acid and sodium borohydride is 25:5:2, and then nano-silver sol is obtained;

[0082] S15. TiO2@BaSO4 is first added to the nano-silver sol and stirred uniformly, then tetrabutyl titanate ethanol solution is added dropwise to the nano-silver sol, after the dropwise addition is completed, nitric acid is added dropwise, stirring reaction is carried out, the stirring temperature is 70℃, the time is 4h, then aging at room temperature is carried out, the aging time at room temperature is 40h, then the obtained powder is subjected to high temperature reaction under nitrogen protection, the high temperature reaction temperature is 600℃, and the time is 4h, and finally Ag-TiO2@BaSO4 is obtained.

[0083] Comparative Example 2

[0084] A preparation method of a radiation refrigeration fabric, the preparation method comprising the following steps:

[0085] S1. One surface of a polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0086] S2. TiO2@BaSO4 is added to the aqueous polyurethane, the content of TiO2@BaSO4 in the aqueous polyurethane is 8wt%, and the TiO2@BaSO4 is uniformly mixed with the aqueous polyurethane by stirring at 900r / min for 20min, and then coated on the hydrophilic treated fabric layer, and then pre-dried at 105℃ for 2min and baked at 140℃ for 4min to obtain a radiation refrigeration fabric;

[0087] The preparation method of the TiO2@BaSO4 comprises the following steps:

[0088] S11. After ball milling, the calcium carbonate is added to water, and ultrasonic dispersion is performed to obtain a calcium carbonate suspension with a concentration of 5.5wt%;

[0089] S12. Barium chloride is added to an aqueous ammonia solution of disodium ethylenediaminetetraacetate, and after uniform mixing and stirring, the pH value is adjusted to neutral, and then the solution is added dropwise to the calcium carbonate suspension prepared in step S11, and after uniform stirring and mixing, sodium sulfate aqueous solution is added dropwise, the molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:1, stirring reaction, deposition of barium sulfate on the surface of calcium carbonate, drying and then heat treatment, the heat treatment temperature is 900℃, the time is 1h, after heat treatment, add dilute hydrochloric acid solution to remove the decomposed calcium oxide, and then perform deposition, drying again to obtain hollow barium sulfate;

[0090] S13. Hollow barium sulfate is ultrasonically dispersed in anhydrous ethanol, the concentration of hollow barium sulfate in ethanol is 4wt%, ammonia water is added, and then tetrabutyl titanate is added, the mass-volume ratio of hollow barium sulfate, ammonia water and tetrabutyl titanate is 0.35g:0.25mL:0.4mL, constant stirring under water bath, water bath temperature is 40℃, stirring time is 15h, centrifugal washing and drying to obtain TiO2@BaSO4.

[0091] Comparative Example 3

[0092] A preparation method of a radiation refrigeration fabric, the preparation method comprising the following steps:

[0093] S1. One surface of a polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0094] S2. Add Ag@BaSO4 into the aqueous polyurethane, the content of Ag@BaSO4 in the aqueous polyurethane is 6.6wt%, stir at 900r / min for 20min, mix Ag@BaSO4 and the aqueous polyurethane uniformly, coat on the hydrophilic treated fabric layer, then pre-dry at 105℃ for 2min, and bake at 140℃ for 4min, to obtain the radiation refrigeration fabric;

[0095] The preparation method of the Ag@BaSO4 comprises the following steps:

[0096] S11. After ball milling, the calcium carbonate is added into water, and ultrasonic dispersion is performed to obtain a calcium carbonate suspension with a concentration of 5.5wt%;

[0097] S12. Barium chloride is added into an aqueous ammonia solution of disodium ethylenediaminetetraacetate, and after uniform mixing and stirring, the pH value is adjusted to neutral, then the solution is added dropwise into the calcium carbonate suspension prepared in step S11, and after uniform stirring and mixing, a sodium sulfate aqueous solution is added dropwise, the molar ratio of barium chloride, sodium sulfate and calcium carbonate is 10:10:1, stirring reaction is performed, barium sulfate is deposited on the surface of the calcium carbonate, drying is performed, and then heat treatment is performed at a temperature of 900℃ for 1h, after the heat treatment, dilute hydrochloric acid solution is added to remove the decomposed calcium oxide, deposition, drying are performed again, and hollow barium sulfate is obtained;

[0098] S13. A silver nitrate solution and a tannic acid solution are mixed and stirred, and then a sodium borohydride solution is rapidly added dropwise under vigorous stirring to react, the molar ratio of silver nitrate, tannic acid and sodium borohydride is 25:5:2, and a nano-silver sol is obtained;

[0099] S14. Hollow barium sulfate is first added into the nano-silver sol and stirred uniformly, then the obtained powder is subjected to high-temperature reaction under nitrogen protection, the high-temperature reaction is performed at a temperature of 600℃ for 4h, and finally Ag@BaSO4 is obtained.

[0100] Comparative Example 4

[0101] A preparation method of a radiation refrigeration fabric, the preparation method comprises the following steps:

[0102] S1. One surface of a polyester fabric is subjected to hydrophilic treatment to obtain a fabric layer;

[0103] S2. Ag, TiO2, BaSO4 were added into the waterborne polyurethane, the content of Ag in the waterborne polyurethane was 2wt%, the content of TiO2 in the waterborne polyurethane was 3.5wt%, the content of BaSO4 in the waterborne polyurethane was 3.5wt%, and the Ag, TiO2 and BaSO4 were mixed with the waterborne polyurethane uniformly by stirring at 900r / min for 20min, and then coated on the hydrophilic treated fabric layer, and then pre-dried at 105℃ for 2min and baked at 140℃ for 4min to obtain the radiation refrigeration fabric.

[0104] Radiation refrigeration performance:

[0105] The solar reflectance and atmospheric window emissivity of the polyester fabric were tested, and the fabric temperature was tested at Wuxi on May 23, 2024 from 10:00 to 15:00 (the average temperature of the environment was 31.5℃).

[0106]

[0107]

[0108] From the above table, it can be seen that the weight of the coated fabric is 50g / m 2 The solar reflectance and atmospheric window emissivity of the coated polyester fabric are 94.2% and 92.9% respectively. The above results show that the radiation refrigeration coated fabric has high radiation refrigeration effect; the fabric temperature and the average temperature of the environment are 26.1℃ and 31.5℃ respectively, and the refrigeration temperature of the fabric is 5.4℃.

[0109] Obviously, the above examples are only examples for the purpose of clarity, and are not limitations of the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A radiation-cooling fabric, characterized in that: The fabric includes a fabric layer and a coating layer. The coating layer is composed of waterborne polyurethane and Ag-TiO2@BaSO4. In the Ag-TiO2@BaSO4, BaSO4 is a hollow core layer, TiO2 is a shell layer, and nano-Ag particles are embedded on TiO2. The preparation method of the Ag-TiO2@BaSO4 includes the following steps: Hollow barium sulfate was ultrasonically dispersed in anhydrous ethanol, ammonia was added, and then tetrabutyl titanate was added. The mixture was kept warm and stirred continuously in a water bath, and then centrifuged, washed, and dried to obtain TiO2@BaSO4. 4； TiO2@BaSO4 was first added to the nano-silver sol and stirred evenly. Then, an ethanol solution of tetrabutyl titanate was added dropwise to the nano-silver sol. After the addition was complete, nitric acid was added dropwise, the reaction was stirred, and then aged at room temperature. Subsequently, the obtained powder was reacted at high temperature under nitrogen protection to finally obtain Ag-TiO2@BaSO4.

2. The method for preparing the radiation-cooling fabric according to claim 1, characterized in that: The preparation method includes the following steps: S1. Apply a hydrophilic treatment to one side of the fabric to obtain the fabric layer; S2. Add Ag-TiO2@BaSO4 to waterborne polyurethane and stir at 800-1000 r / min for 10-30 min to make Ag-TiO2@BaSO4 and waterborne polyurethane evenly mixed. Coat the mixture onto the hydrophilic fabric layer, and then pre-bake at 100-110℃ for 1-3 min and bake at 130-155℃ for 2-5 min to obtain the radiation cooling fabric.

3. The method for preparing the radiation-cooling fabric according to claim 2, characterized in that... The fabric can be any one of natural fiber cotton, synthetic fiber fabric or regenerated fiber fabric.

4. The method for preparing the radiation-cooling fabric according to claim 2, characterized in that: The content of Ag-TiO2@BaSO4 in the waterborne polyurethane is 5-8 wt%.

5. The radiant cooling fabric according to claim 1, characterized in that: The preparation method of Ag-TiO2@BaSO4 further includes the following steps: S11. After ball milling calcium carbonate, add it to water and ultrasonically disperse it evenly to obtain a calcium carbonate suspension; S12. Add barium chloride to an ammonia solution of disodium ethylenediaminetetraacetate, mix and stir until homogeneous, adjust the pH to neutral, and then add the solution dropwise to the calcium carbonate suspension prepared in step S11. After mixing and stirring until homogeneous, add sodium sulfate solution dropwise and stir to react, depositing barium sulfate on the surface of calcium carbonate. After drying, perform heat treatment. After heat treatment, add dilute hydrochloric acid solution to remove the calcium oxide obtained from decomposition, and perform deposition and drying again to obtain hollow barium sulfate. S13. Mix and stir silver nitrate solution and tannic acid solution, then rapidly add sodium borohydride solution dropwise under vigorous stirring to react and obtain nano silver sol.

6. The radiation cooling fabric according to claim 5, characterized in that: The concentration of the calcium carbonate suspension in step S11 is 2-6 wt%.

7. The radiant cooling fabric according to claim 5, characterized in that: In step S12, the molar ratio of barium chloride, sodium sulfate, and calcium carbonate is 10:10:0.5-2, the heat treatment temperature is 800-1000℃, and the time is 0.5-1.5h.

8. The radiation cooling fabric according to claim 1, characterized in that: The hollow barium sulfate, ammonia and tetrabutyl titanate are present in a mass-to-volume ratio of 0.2-0.4g:0.1-0.3mL:0.3-0.5mL, the concentration of hollow barium sulfate in ethanol is 3-5wt%, the water bath temperature is 40-45℃, and the stirring time is 10-15h.

9. The radiant cooling fabric according to claim 5, characterized in that: In step S13, the molar ratio of silver nitrate, tannic acid, and sodium borohydride is 20-30:4-6:1-3.

10. The radiation cooling fabric according to claim 1, characterized in that: The stirring temperature after adding nitric acid is 60-75℃ and the stirring time is 3-5h; the aging time at room temperature is 40-60h; and the high-temperature reaction temperature is 500-600℃ and the time is 2-4h.

Images