Radiation evaporation integrated refrigeration fabric and preparation method thereof

Abstract

The invention provides radiation and evaporation integrated refrigeration fabric and a preparation method thereof, and belongs to the field of radiation refrigeration materials. The radiation and evaporation integrated refrigeration fabric comprises a hydrophobic layer, a transfer layer, an evaporation layer and a radiation refrigeration layer with the hydrophobic property. The four layers are prepared layer by layer through an electrostatic spinning technology and are stacked layer by layer. The hydrophobic layer, the transfer layer and the evaporation layer have the hygroscopic gradient from hydrophobic to hydrophilic and the diameter gradient from large to small of the fiber diameter. Sweat is prevented from reaching the outer surface of the fabric through the hydrophobic radiation refrigeration layer on the top layer, and the problem that the radiation refrigeration effect is reduced due to the fact that the sweat is gathered on the surface of the fabric and strongly absorbs sunlight in the near-infrared band is solved. Sweat generated on the skin side can be quickly transferred from the hydrophobic layer and transferred to the evaporation layer for evaporation under the action of pressure difference, so that the sweat evaporation rate is increased while the sticky feeling of the sweat on the skin side is avoided. Effective human body cooling is achieved through the combined action of radiation refrigeration and evaporation refrigeration.

Description

Technical Field

[0001] The invention relates to the technical field of radiation refrigeration materials, and in particular to a radiation evaporation integrated refrigeration fabric and a preparation method thereof. Background Art

[0002] Zero-energy radiative cooling technology based on personal thermal management is the most promising way to achieve thermal comfort for the human body. Through material selection and structural design, radiative cooling fabrics can achieve high reflectivity in the solar radiation band of 0.3-2.5μm to prevent solar heat input, and high emissivity in the human radiation band of 7-14μm to allow human body heat to radiate to outer space through the mid-infrared atmospheric window (8-13μm) for cooling.

[0003] The patent with publication number CN113136724A discloses a radiation cooling fabric, which attaches a material with a high refractive index to a silk fiber, and can achieve a temperature of about 3.6°C lower than the environment under sunlight. Existing radiation cooling fabrics can achieve excellent human body cooling effect when the human body does not produce sweat. However, when the ambient temperature is greater than 30°C, sweat evaporation and thermal radiation account for most of the heat dissipation of the human body. At this time, it is necessary to design a cooling fabric that can manage both the thermal radiation and sweat evaporation of the human body to achieve effective human body cooling. At present, the bottleneck of achieving effective radiation cooling and sweat evaporation cooling for human body cooling at the same time is that when sweat accumulates on the surface of the fabric, due to the high absorption of water to the near-infrared band of sunlight, the reflectivity of the sunlight band will be greatly reduced, thereby reducing the cooling performance of radiation cooling.

[0004] In view of this, it is necessary to design a radiation evaporation integrated refrigeration fabric and a preparation method thereof to solve the above problems. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a radiation evaporation integrated refrigeration fabric and a preparation method thereof, wherein the radiation evaporation integrated refrigeration fabric comprises a hydrophobic layer, a transfer layer, an evaporation layer and a radiation refrigeration layer with hydrophobic properties stacked from bottom to top. The top layer with hydrophobic radiation refrigeration layer prevents sweat from reaching the outer surface of the fabric, thereby solving the problem that sweat accumulates on the surface of the fabric and strongly absorbs sunlight in the near-infrared band, thereby reducing the radiation refrigeration effect. The hydrophobic layer, the transfer layer, and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameter. Through the action of the pressure difference, the sweat generated on the skin side can be quickly transferred from the hydrophobic layer and guided to the evaporation layer for evaporation, thereby avoiding the sticky feeling of sweat on the skin side and accelerating the sweat evaporation rate. Effective human body cooling is achieved by combining the combined action of radiation refrigeration and evaporative refrigeration.

[0006] In the first aspect, an embodiment of the present application provides a radiation evaporation integrated refrigeration fabric, comprising a hydrophobic layer, a transfer layer, an evaporation layer and a radiation refrigeration layer with hydrophobic properties stacked from bottom to top; the aforementioned four layers are prepared layer by layer and stacked layer by layer through electrospinning technology; the hydrophobic layer, transfer layer and evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a fiber diameter gradient from large to small; the material of the transfer layer is a mixture of the materials selected for the hydrophobic layer and the evaporation layer.

[0007] Furthermore, the radiation cooling layer is a white polymer electrospun membrane with hydrophobic properties; the polymer of the radiation cooling layer is one or a mixture of polymethyl methacrylate, polylactic acid, polytetrafluoroethylene, and polyvinylidene fluoride.

[0008] Furthermore, the fiber diameter of the hydrophobic layer is 1 μm-3 μm, the fiber diameter of the transfer layer is 400-800 nm, and the fiber diameter of the evaporation layer is 100-300 nm.

[0009] Furthermore, the polymer of the hydrophobic layer is polyurethane, polylactic acid or a mixture of both.

[0010] Furthermore, the polymer of the evaporation layer is polyacrylonitrile, polyamide or a mixture of the two.

[0011] Furthermore, the contact angle of the hydrophobic layer is greater than 90°, the contact angle of the transfer layer becomes 0 within 50s-150s, and the contact angle of the evaporation layer becomes 0 within 0s-2s.

[0012] Furthermore, the thickness of the hydrophobic layer is 10-20 μm, the thickness of the transfer layer is 40-60 μm, the thickness of the evaporation layer is 80-100 μm, and the thickness of the radiation cooling layer is 400-500 μm.

[0013] Furthermore, the fiber diameter of the radiation cooling layer is 400-700 nm.

[0014] In the second aspect, the embodiment of the present application provides a method for preparing a radiation evaporation integrated refrigeration fabric, which is used to prepare the aforementioned radiation evaporation integrated refrigeration fabric, comprising the following steps: using electrospinning technology to sequentially prepare a hydrophobic layer, a transfer layer, an evaporation layer, and a hydrophobic radiation refrigeration layer stacked in layers; the polymer of the radiation refrigeration layer is a mixture of one or more of polymethyl methacrylate, polylactic acid, polytetrafluoroethylene, and polyvinylidene fluoride; the polymer of the hydrophobic layer is a mixture of one or two of polyurethane and polylactic acid; the polymer of the evaporation layer is a mixture of one or two of polyacrylonitrile and polyamide; the material of the transfer layer is a mixture of the hydrophobic layer and the evaporation layer; the hydrophobic layer, the transfer layer, and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameter. The fiber diameter of each layer is regulated by adjusting the solution concentration, voltage, and push speed used for electrospinning.

[0015] Beneficial effects of the present invention:

[0016] 1. The radiation evaporation integrated refrigeration fabric provided by the present invention adopts a multi-layer design. The top layer of the radiation refrigeration layer with hydrophobicity prevents sweat from reaching the outer surface of the fabric, thereby solving the problem that sweat accumulates on the surface of the fabric and strongly absorbs sunlight in the near-infrared band, thereby reducing the radiation refrigeration effect. It is composed of a hydrophobic layer, a transfer layer and an evaporation layer, and has a hygroscopicity gradient from hydrophobic to hydrophilic and a fiber diameter gradient from large to small. Through the action of the pressure difference, the sweat generated on the skin side can be quickly transferred from the hydrophobic layer and guided to the evaporation layer for evaporation, avoiding the sticky feeling of sweat on the skin side while accelerating the sweat evaporation rate. Effective human body cooling is achieved by combining the radiative refrigeration and evaporative refrigeration.

[0017] 2. The present invention realizes unidirectional moisture conduction of sweat and accelerates the evaporation rate through the gradient of hygroscopicity, thereby improving the cooling effect of sweat evaporation. At the same time, the outermost hydrophobic radiation cooling layer ensures high solar reflectivity when wetted by sweat, thereby realizing the radiation cooling effect.

[0018] 3. The electrospinning technology used in the present invention has a simple preparation method, novel structure, is easy to manufacture and apply on a large scale, and has significant economic value.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the radiation evaporation integrated refrigeration fabric of the present invention.

[0022] Figure 2 It is the reflectivity of the radiation evaporation integrated refrigeration fabric prepared in Example 1 in the solar light band in dry and wet states.

[0023] Figure 3 It is the mid-infrared band emissivity of the radiation evaporation integrated refrigeration fabric prepared in Example 1 in dry and wet states.

[0024] Figure 4 The temperature comparison of cellulose acetate film, the radiation evaporation integrated refrigeration fabric prepared in Example 1, and cotton under direct sunlight.

[0025] Figure 5 Comparison of the simulated skin surface temperature under direct sunlight when covered by cellulose acetate film, the radiation evaporation integrated refrigeration fabric prepared in Example 1, and cotton. DETAILED DESCRIPTION

[0026] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0033] See also Figure 1 As shown, the embodiment of the present application provides a radiation evaporation integrated refrigeration fabric, including a hydrophobic layer, a transfer layer, an evaporation layer and a radiation refrigeration layer with hydrophobic properties stacked from bottom to top; the aforementioned four layers are prepared layer by layer by electrospinning technology and stacked layer by layer. The hydrophobic layer, the transfer layer, and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameters.

[0034] The top radiative cooling layer is a white polymer electrospun membrane with hydrophobic properties.

[0035] The polymer of the radiation cooling layer can be one or a mixture of polymethyl methacrylate (PMMA), polylactic acid (PLA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF).

[0036] The thickness of this layer is 400-500 μm and the fiber diameter is 400-700 nm.

[0037] The polymer of the hydrophobic layer is one of polyurethane (PU) and polylactic acid (PLA) or a mixture of the two. The fiber diameter of the layer is 1 μm-3 μm and the thickness is 10-20 μm.

[0038] The polymer of the evaporation layer is one of polyacrylonitrile (PAN) and polyamide (PA) or a mixture of the two. The fiber diameter of the layer is 100-300nm and the thickness is 80-100μm.

[0039] The polymer used in the transfer layer is a mixture of the polymers used in the hydrophobic layer and the evaporation layer, wherein the proportion of the material used in the hydrophobic layer is 5%-30%.

[0040] The fiber diameter of the transfer layer is 400-800nm ​​and the thickness is 40-60μm.

[0041] The contact angle of the hydrophobic layer is greater than 90°, the contact angle of the transfer layer becomes 0 within 50s-150s, and the contact angle of the evaporation layer becomes 0 within 0s-2s. That is, the hydrophobic layer, the transfer layer, and the evaporation layer form a hygroscopic gradient from hydrophobic to hydrophilic.

[0042] The preparation method of the aforementioned radiation evaporation integrated refrigeration fabric comprises the following steps: using electrostatic spinning technology to sequentially prepare a hydrophobic layer, a transfer layer, an evaporation layer and a hydrophobic radiation refrigeration layer stacked in layers; the polymer of the radiation refrigeration layer is a mixture of one or more of polymethyl methacrylate, polylactic acid, polytetrafluoroethylene, and polyvinylidene fluoride; the polymer of the hydrophobic layer is a mixture of one or two of polyurethane and polylactic acid; the polymer of the evaporation layer is a mixture of one or two of polyacrylonitrile and polyamide; the material of the transfer layer is a mixture of the materials selected for the hydrophobic layer and the evaporation layer; the hydrophobic layer, the transfer layer, and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameters. The fiber diameter of each layer is regulated by adjusting the solution concentration, voltage, and push speed used for electrostatic spinning.

[0043] The radiation evaporation integrated refrigeration fabric provided by the present invention adopts a multi-layer design, and the top layer of the hydrophobic radiation refrigeration layer prevents sweat from reaching the outer surface of the fabric, thereby solving the problem that sweat accumulates on the surface of the fabric and strongly absorbs sunlight in the near-infrared band, thereby causing a decrease in the radiation refrigeration effect. It is composed of a hydrophobic layer, a transfer layer and an evaporation layer, and has a hygroscopicity gradient from hydrophobic to hydrophilic and a fiber diameter gradient from large to small. Through the action of the pressure difference, the sweat generated on the skin side can be quickly transferred from the hydrophobic layer and guided to the evaporation layer for evaporation, avoiding the sticky feeling of sweat on the skin side while accelerating the sweat evaporation rate. Effective human body cooling is achieved by combining the radiative refrigeration and evaporative refrigeration.

[0044] The present invention realizes unidirectional moisture conduction of sweat and accelerates the evaporation rate through the gradient of hygroscopicity, so that the evaporation cooling effect of sweat is improved. At the same time, the high solar reflectivity under the condition of sweat wetting is ensured through the outermost hydrophobic radiation cooling layer, thereby realizing the radiation cooling effect.

[0045] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0046] Example 1

[0047] See also Figure 1 As shown, this embodiment provides a radiation evaporation integrated refrigeration fabric, including a hydrophobic layer, a transfer layer, an evaporation layer and a radiation refrigeration layer with a hydrophobic property stacked from bottom to top.

[0048] The materials used for each layer are: the radiation cooling layer is hydrophobic polyvinylidene fluoride, the evaporation layer is polyacrylonitrile, the hydrophobic layer is polyurethane, and the transfer layer is a mixture of 70% polyacrylonitrile and 30% polyurethane. Each layer is stacked layer by layer using electrospinning technology to prepare the radiation evaporation integrated cooling fabric.

[0049] The fabric has a wetting gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameter from the hydrophobic layer to the evaporation layer. Specifically, the contact angle of the hydrophobic layer is 105°, the contact angle of the transfer layer becomes 0 within 130 seconds, and the contact angle of the evaporation layer becomes 0 within 2.5 seconds.

[0050] The fiber diameters of the hydrophobic layer, transfer layer, and evaporation layer are 245nm, 500nm, and 1.1μm, respectively. This arrangement achieves unidirectional moisture conduction of sweat from the hydrophobic layer to the evaporation layer, accelerating the evaporation rate of sweat.

[0051] The preparation method of the radiation evaporation integrated refrigeration fabric comprises the following steps: selecting the materials of each layer, and using electrospinning technology to sequentially prepare a hydrophobic layer, a transfer layer, an evaporation layer, and a radiation refrigeration layer with hydrophobic properties. The hydrophobic layer, the transfer layer, and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameters. The fiber diameter of each layer is regulated by adjusting the concentration, voltage, and push speed of the solution used in the electrospinning process. The specific regulation method can be set according to the actual situation and will not be repeated here.

[0052] Performance Test:

[0053] The reflectivity of the radiation evaporation integrated refrigeration fabric in the solar band of Example 1 was tested using a UV-vis-NIR spectrophotometer (uv3600, Shimadzu) equipped with an integrating sphere (ISR-310) model. Figure 2 For test results.

[0054] The infrared band emissivity of the radiation evaporation integrated refrigeration fabric of Example 1 was tested using a Fourier transform infrared spectrometer (Nicolet IS50, ThermoFisher) and a gold integrating sphere (SP-GPS-020-SL, Pike). Figure 3 For test results.

[0055] For comparison, commercial fabric cotton (ROMON's pure cotton short-sleeved shirt) and radiation cooling fabric cellulose acetate electrospun membrane were selected as comparison samples.

[0056] The preparation method of the radiation cooling fabric cellulose acetate electrostatic spinning membrane is as follows: the electrostatic spinning process is adopted, and the spinning solution is cellulose acetate powder (mass fraction is 17%) dissolved in acetone / dimethylformamide.

[0057] Test the temperature of cellulose acetate film, radiation evaporation integrated cooling fabric and cotton under direct sunlight. Figure 4 For test results.

[0058] The test process is: using thermocouples to detect temperature changes under cellulose acetate film, radiant evaporative integrated cooling fabric and cotton.

[0059] The instrument used was a K-type, Omega thermocouple.

[0060] Test the surface temperature of simulated skin covered by cellulose acetate film, radiation evaporation integrated cooling fabric and cotton under direct sunlight. Figure 5 For test results.

[0061] The test process is: use power at 250W / m 2 The heating plate is powered by a power of , the sample to be tested is covered on the heating plate, and the temperature changes under the three fabrics are detected by thermocouples.

[0062] The instruments used are K-type, Omega thermocouple, Kapton heating plate, and Array power supply.

[0063] Test result analysis:

[0064] from Figure 2It can be seen that the radiation evaporation integrated cooling fabric can achieve a 97% solar waveband reflectivity in a dry state. Moreover, under the action of the hydrophobic radiation cooling layer, it can still maintain a 93.4% solar waveband reflectivity when wetted by sweat, preventing the input of solar heat.

[0065] from Figure 3 It can be seen that the radiation evaporation integrated cooling fabric can achieve a high emissivity of more than 90% in the mid-infrared 8-13μm band with or without sweat wetting, and can achieve a radiation cooling effect.

[0066] from Figure 4 It can be seen that in the wet state, the commercial fabric cotton and cellulose acetate film have a temperature higher than the ambient temperature due to the decrease in solar reflectivity, and no net cooling power output is achieved.

[0067] The radiation evaporation integrated cooling fabric of Example 1 can cool at 925W m at noon when wetted with sweat. -2 Under solar irradiation, a sub-ambient cooling effect of about 6.7°C below the ambient temperature (27.2°C) is achieved. That is, in a wet state, the radiation evaporation integrated cooling fabric still has spectral performance that can achieve radiation cooling.

[0068] from Figure 5 It can be seen that when the heating plate is 250W m -2 The heating power simulates skin heating and is 32mL min -1 m -2 When sweating at a rate of , the simulated skin surface covered by the radiant evaporative integrated cooling fabric of Example 1 can achieve a cooling of 6.4°C compared to the traditional radiant cooling fabric cellulose acetate film and about 8.1°C compared to the commercial cotton fabric.

[0069] It should be noted that the polymer of the radiation cooling layer may also be polymethyl methacrylate, polylactic acid, polytetrafluoroethylene, or a mixture of several thereof.

[0070] The polymer of the hydrophobic layer may also be polylactic acid, or a mixture of polyurethane and polylactic acid.

[0071] The polymer of the evaporation layer may also be polyamide, or a mixture of polyacrylonitrile and polyamide.

[0072] Comparative Example 1

[0073] Comparative Example 1 provides a fabric, which is different from Example 1 in that no transfer layer is provided, and the rest is substantially the same as Example 1, which will not be described herein.

[0074] Comparative Example 2

[0075] Comparative Example 1 provides a fabric, which is different from Example 1 in that a radiative cooling layer with hydrophobic properties is not provided, and the rest is substantially the same as Example 1, which will not be described herein.

[0076] Comparative Example 3

[0077] Comparative Example 1 provides a fabric, which is different from Example 1 in that the fiber diameters of the hydrophobic layer, the transfer layer, and the evaporation layer are the same, all 500 nm, and the rest are substantially the same as Example 1, which will not be repeated here.

[0078] The fabrics prepared in Example 1 and Comparative Examples 1-3 were tested for unidirectional moisture conduction performance (from skin side to outside), cooling performance (when wetted with sweat, at noon at 925 W m -2 cooling effect under solar radiation), cooling performance (heating plate with 250W m -2 The heating power simulates skin heating and is 32mL min -1 m -2 The cooling effect when sweating at a certain rate was tested) and the results are shown in the following table.

[0079] Table 1

[0080]

[0081]

[0082] As can be seen from the above table, the radiation evaporation integrated refrigeration fabric can achieve better cooling performance and refrigeration performance than comparative examples 1-3. Among them, in comparative example 2, due to the absence of the outermost radiation refrigeration layer with hydrophobic properties, the sub-ambient cooling effect cannot be achieved under wet conditions, and it is only 2°C lower than the traditional radiation refrigeration fabric. In comparative examples 1 and 3, since the three layers with both diameter gradient and wettability gradient cannot be achieved, the unidirectional moisture conduction effect cannot be achieved, and therefore the cooling performance and refrigeration performance are worse than those of Example 1.

[0083] In summary, the radiation evaporation integrated refrigeration fabric provided by the present invention adopts a multi-layer design, and the top layer has a hydrophobic radiation refrigeration layer to prevent sweat from reaching the outer surface of the fabric, thereby solving the problem that sweat accumulates on the surface of the fabric and strongly absorbs sunlight in the near-infrared band, thereby causing a decrease in the radiation refrigeration effect. It is composed of a hydrophobic layer, a transfer layer and an evaporation layer, and has a hygroscopicity gradient from hydrophobic to hydrophilic and a diameter gradient from large to small fiber diameter. Through the action of the pressure difference, the sweat generated on the skin side can be quickly transferred from the hydrophobic layer and guided to the evaporation layer for evaporation, avoiding the sticky feeling of sweat on the skin side while accelerating the sweat evaporation rate. Effective human body cooling is achieved by combining the combined action of radiation refrigeration and evaporative refrigeration.

[0084] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, within the scope of the subject matter of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A radiation evaporation integrated refrigeration fabric, characterized in that: It includes a hydrophobic layer, a transfer layer, an evaporation layer and a radiant cooling layer with hydrophobic properties stacked from bottom to top; the above four layers are prepared layer by layer through electrospinning technology and stacked layer by layer; the hydrophobic layer, the transfer layer and the evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a fiber diameter gradient from large to small; the material of the transfer layer is a mixture of the materials selected from the hydrophobic layer and the evaporation layer.

2. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The radiation cooling layer is a white polymer electrostatic spinning membrane with hydrophobic properties; the polymer of the radiation cooling layer is one or a mixture of polymethyl methacrylate, polylactic acid, polytetrafluoroethylene, and polyvinylidene fluoride.

3. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The fiber diameter of the hydrophobic layer is 1 μm-3 μm, the fiber diameter of the transfer layer is 400-800 nm, and the fiber diameter of the evaporation layer is 100-300 nm.

4. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The polymer of the hydrophobic layer is polyurethane, polylactic acid or a mixture of the two.

5. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The polymer of the evaporation layer is polyacrylonitrile, polyamide or a mixture of the two.

6. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The contact angle of the hydrophobic layer is greater than 90°, the contact angle of the transfer layer becomes 0 within 50s-150s, and the contact angle of the evaporation layer becomes 0 within 0s-2s.

7. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The thickness of the hydrophobic layer is 10-20 μm, the thickness of the transfer layer is 40-60 μm, the thickness of the evaporation layer is 80-100 μm, and the thickness of the radiation cooling layer is 400-500 μm.

8. The radiation evaporation integrated refrigeration fabric according to claim 1, characterized in that: The fiber diameter of the radiation cooling layer is 400-700nm.

9. A method for preparing a radiation evaporation integrated refrigeration fabric, used for preparing the radiation evaporation integrated refrigeration fabric according to any one of claims 1 to 8, characterized in that: The following steps are involved: The electrostatic spinning technology is used to sequentially prepare stacked hydrophobic layers, transfer layers, evaporation layers and radiation refrigeration layers with hydrophobic properties; the polymer of the radiation refrigeration layer is one or a mixture of polymethyl methacrylate, polylactic acid, polytetrafluoroethylene and polyvinylidene fluoride; the polymer of the hydrophobic layer is one or a mixture of polyurethane and polylactic acid; the polymer of the evaporation layer is one or a mixture of polyacrylonitrile and polyamide; the material of the transfer layer is a mixture of the materials selected from the hydrophobic layer and the evaporation layer; the hydrophobic layer, transfer layer and evaporation layer have a hygroscopicity gradient from hydrophobic to hydrophilic and a fiber diameter gradient from large to small.

10. The method for preparing the radiation evaporation integrated refrigeration fabric according to claim 9, characterized in that: The fiber diameter of each layer can be controlled by adjusting the concentration of the solution, voltage and pushing speed during the electrospinning process.

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