A composite textile with dual functions of passive radiative cooling and thermal insulation and a preparation method thereof

Abstract

The application discloses a composite textile with passive radiative cooling and heat preservation functions and a preparation method thereof, and the method comprises the following steps: preparing a porous polypropylene fiber membrane through a melt-blown process, depositing silicon dioxide nanoparticles through ultrasonic deposition, and then adopting a laminating process to combine a polyurethane microporous membrane and a carbon nanotube film, so that the composite textile with double-mode heat management characteristics is obtained. When the polyurethane layer faces the sun, the material shows high solar reflectivity and high infrared emissivity in the atmospheric window band, so that efficient passive radiative cooling is realized; when the carbon nanotube film faces the sun, the material has high solar absorptivity and low infrared emissivity, so that excellent heat preservation performance is realized. The method is simple in process, suitable for large-scale production, can effectively reduce energy consumption, and has a wide application prospect in the fields of personal heat management and the like.

Description

Technical Field

[0001] This invention belongs to the field of functional textile technology, specifically relating to a composite textile prepared by meltblown process and multilayer composite technology and its preparation method. The textile has both passive radiative cooling and heat preservation functions, and has certain waterproof and breathable properties, making it suitable for outdoor clothing, building shelters and smart wearable devices. Background Technology

[0002] With the ever-increasing demand for sustainable energy and growing concern about climate change, efficient thermal management technologies have become crucial for reducing energy consumption in buildings, vehicles, and personal wearable devices. Radiative thermal management technologies, including passive radiative cooling and solar heating, are considered a promising low-carbon energy solution. This technology utilizes the radiation difference between the sun (approximately 5800K) and outer space (approximately 3K) to achieve temperature regulation through natural radiation processes without requiring additional energy input.

[0003] In passive radiative cooling, materials with high reflectivity to sunlight are typically used, allowing the surface to dissipate heat to outer space through atmospheric transparent windows (8-13 μm), thus achieving temperatures below ambient levels even under direct sunlight. Conversely, solar heating relies on materials with high absorptivity to sunlight and low emissivity to infrared radiation to absorb and store energy, providing localized heating in cold climates or winter environments. These passive thermal management strategies show great potential in diverse applications such as smart buildings, thermal clothing, and energy-efficient shelters. Despite significant progress in this field, most passive thermal regulation systems remain single-mode designs, focusing solely on either cooling or heating. This limitation significantly reduces their applicability in dynamic environments such as day-night cycles, seasonal changes, or climate change. To address this issue, researchers have devoted considerable effort to developing dual-mode or switchable thermal regulation systems. Among these, materials based on external stimulus responses (such as phase change materials, shape memory polymers, and liquid crystal-based coatings) show promise in adaptively controlling optical and thermal properties. However, these materials typically rely on external stimuli (such as temperature, light, or voltage), have complex manufacturing processes, and suffer from problems such as poor stability or slow response speed, making it difficult to meet the needs of large-scale production and practical applications.

[0004] In recent years, asymmetric structures with dual-mode thermal management capabilities have gradually attracted widespread attention as an alternative that requires no external drive and can be functionally controlled through design. These materials exhibit orientation-dependent thermal responses, switching between cooling and heating modes simply by changing the surface orientation. Typical research includes multilayer films, porous foams, and nanostructured membranes. In particular, textile-based dual-mode thermal management structures have become a research hotspot due to their flexibility, mechanical stability, and compatibility with scalable manufacturing processes. For example, porous nylon membranes modified with transition metal carbides (MXene) can achieve rapid switching between heating and cooling after a simple flip (M. Feng, S. Feng, T. Yu, S. Zhu, H. Cai, X. He, Y. Zhou, Versatile and comfortable janus fabrics for switchable personal thermal management and electromagnetic interference shielding, Adv. Fiber Mater., 2024, 6: 911-924; Multifunctional comfortable Janus fabrics for switchable personal thermal management and electromagnetic interference shielding, Advanced Fiber Materials). However, developing bimodal textiles that combine high thermal regulation, mechanical durability, water vapor permeability, and long-term stability still presents significant challenges.

[0005] Existing publicly available Chinese invention patents also indicate that some research attempts to achieve passive radiative cooling or a dual-mode cooling / heating function through multi-layered structures. For example: Chinese invention patent CN116120794B, "A passive radiation cooling composite coating and its preparation method," uses a composite coating consisting of a bottom layer and a top layer to achieve high infrared emission and sunlight reflection during the day. However, this solution can only achieve passive radiation cooling and cannot also provide warmth.

[0006] Chinese invention patent CN118326622A, "A dual-mode radiant heat management leather nanofabric and its preparation method," discloses a composite structure of a heating layer and a cooling layer that self-adhedes through a spinning process, enabling switching between cooling and warming modes. However, due to its relatively simple fabric structure, it still has shortcomings in terms of comfort and durability.

[0007] In summary, the existing technologies in the field of functional temperature control films or textiles still have the following shortcomings: (1) Most research or patents focus only on a single function (cooling only or heat preservation only), and it is difficult to take into account dual functions; (2) Existing solutions often rely on complex multi-layer structures or external mechanical drives, which are not conducive to large-scale preparation and daily application; (3) There are still limitations in taking into account breathability, flexibility and durability.

[0008] Therefore, there is an urgent need to develop a composite textile with a simple structure, easy process, and scalable production, which can achieve both passive radiative cooling and heat preservation functions, while also having certain waterproof and breathable properties, so as to be suitable for applications such as outdoor clothing, building shelters, and smart wearable devices. Summary of the Invention

[0009] This invention aims to address the limitations of traditional textiles in thermal management, particularly the lack of comprehensive performance combining passive radiative cooling, thermal insulation, waterproofing, breathability, and electrical functions. By proposing a method for preparing a composite structure, this invention can obtain novel composite textiles that combine optical control properties with practical textile attributes, meeting the needs of fields such as building energy conservation, outdoor protection, and smart wearables.

[0010] To achieve the above objectives, the present invention provides a method for preparing a composite textile with both passive radiative cooling and heat preservation functions, comprising the following steps: (1) Polypropylene (PP) granules are melt-extruded and hot-air stretched using a melt-blown process to collect and form a high-porosity PP base film, which is then dried. (2) Silica (SiO2) nanoparticles were dispersed in deionized water and a stable dispersion was obtained by ultrasonic treatment; (3) The PP base film is pretreated by cleaning and drying; (4) The PP base film is immersed in SiO2 dispersion, and SiO2 nanoparticles are deposited on the fiber surface by ultrasonic treatment; (5) The PP / SiO2 membrane after deposition is rinsed and dried to obtain a SiO2-modified PP base membrane; (6) Different functional films are laminated on both sides of the SiO2-modified PP base film: a thermoplastic polyurethane (TPU) microporous film is laminated on one side and a carbon nanotube (CNT) film is laminated on the other side, and a composite textile is obtained by hot pressing.

[0011] Furthermore, the method may also have the following preferred embodiments: The polypropylene granules have a melt flow index of 800-1500 g / 10 min and a melting temperature of 240-270 °C. They are extruded through a 0.3 mm diameter spinneret and collected under hot air stretching to form a base film with a thickness of 100-150 μm.

[0012] The PP base film in step (1) is hot-pressed at 130℃ and 0.3-0.5MPa for 0.5-1.5min to enhance its mechanical stability.

[0013] The SiO2 nanoparticles have an average particle size of 100-500 nm and a dispersion concentration of 0.5-10 wt%.

[0014] The deposition step in step (4) uses an ultrasonic frequency of 30-50kHz, a power of 100-300W, and a time of 30-120min.

[0015] The TPU microporous membrane has a thickness of 20-50μm, a waterproof performance of 10,000-20,000mm water pressure, and a breathability of 10,000-15,000g / m² / 24h.

[0016] The CNT film has a thickness of 50-100 μm and a surface resistivity of 5-20 Ω / sq.

[0017] Step (6) Hot pressing composite conditions are temperature 80-100℃, pressure 0.5-0.8MPa, time 8-15s, and spray adhesive is used in the composite process.

[0018] Furthermore, the present invention also provides a composite textile prepared by the above method, wherein the total thickness of the composite textile is 150-300 μm. Its infrared emissivity in the 8-13 μm band is 0.90-0.98, and its solar reflectivity in the 0.3-2.5 μm band is 0.80-0.95.

[0019] The composite textile of this invention achieves multiple functions, including passive radiative cooling, waterproofing, breathability, and photothermal regulation, through the synergistic effect of a high-porosity PP base membrane, a SiO2 nanoparticle modification layer, a thermoplastic TPU microporous membrane, and a CNT film. First, the PP base membrane, prepared by meltblown technology, has micron-sized fiber diameters and a high-porosity structure, which significantly reduces the effective thermal conductivity of the material while maintaining flexibility, and provides a large specific surface area for subsequent nanoparticle deposition. Second, the SiO2 nanoparticles (100-500 nm) deposited on the fiber surface can effectively scatter and reflect incident sunlight in the visible-near-infrared band, while exhibiting high infrared emissivity in the 8-13 μm atmospheric window band, thereby enhancing passive radiative cooling performance. Furthermore, the TPU microporous membrane on one side not only imparts excellent waterproof performance to the textile but also maintains good breathability, ensuring wearing comfort and stability for outdoor applications; while the CNT film on the other side has excellent photothermal conversion performance, enabling regulation of infrared heating function. Therefore, this invention achieves a balance between cooling and heating, and protection and functionality of materials through an asymmetric composite structure design. The proposed process is simple, suitable for large-scale continuous production, and can expand the application of composite textiles in fields such as building energy conservation, smart wearables, and environmental control.

[0020] The beneficial effects of this invention are as follows: By depositing SiO2 nanoparticles on the surface of a PP base film, the radiative emissivity of the material in the mid-infrared band is improved, thereby enhancing passive radiative cooling performance; waterproof and breathable functions are achieved through laminating a TPU microporous membrane, ensuring the comfort of the textile in outdoor applications; and the textile is endowed with good photothermal absorption and electrical conductivity through laminating a CNT film, which can accommodate both heating and electrical functions. The prepared composite textile has the advantages of good flexibility, structural stability, diverse functions, and large-scale production, and can be widely used in energy-saving building cladding materials, outdoor protective fabrics, and smart wearable devices. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the principle of the composite textile of the present invention; Figure 2 This is a schematic diagram of the preparation process of the present invention; Figure 3 This is a SEM image of the PP base film from Example 1; Figure 4 This is a SEM image of SiO2 nanospheres deposited on a PP-based film in Example 1; Figure 5 These are XRD patterns of the PP-based film and the deposited SiO2 nanospheres from Example 1. Figure 6 This is the temperature test curve of Example 1; Figure 7This is a SEM image of the PP base film from Example 2; Figure 8 This is a SEM image of SiO2 nanospheres deposited on a PP-based film in Example 2; Figure 9 This is the EDS image of SiO2 nanospheres deposited on a PP-based film in Example 2; Figure 10 This is the temperature test curve of Example 2; Figure 11 This is a SEM image of the TRU microporous membrane from Example 3; Figure 12 This is a SEM image of the carbon nanotube film from Example 3; Figure 13 This is a water vapor transmission rate test chart from Example 3; Figure 14 These are photographs of the actual product in Example 3; Figure 15 This is the reflectance test curve of the solar spectrum in Example 3; Figure 16 This is the atmospheric window emissivity test curve of Example 3; Figure 17 These are average reflectance of the solar spectrum and average emissivity of the atmospheric window for Examples 4 and 5. Detailed Implementation

[0022] This invention aims to provide a composite textile with both passive radiative cooling and heat preservation functions, as well as its preparation method, solving the problem that existing textiles cannot simultaneously achieve bidirectional control of cooling and heat preservation. By constructing an asymmetric multilayer structure, one side has high reflectivity / high emissivity to achieve radiative cooling, while the other side has high absorption / low emissivity to achieve heat preservation, thereby achieving efficient passive temperature management.

[0023] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited thereto. Example 1

[0024] This invention discloses a composite textile that combines passive radiative cooling and heat preservation functions, and its preparation method includes the following steps: (S1) PP Substrate Preparation: PP granules with a melt flow index of 1000 g / 10 min were selected and extruded through a 0.3 mm diameter spinneret at a melting temperature of 260 °C using a melt-blowing process. The hot air stretching speed was 30 m / s, resulting in a PP base film with a thickness of 120 μm and a porosity of 85%. The PP base film was hot-pressed at 130 °C and 0.4 MPa for 1 min to enhance its mechanical stability. Figure 3 As shown, the SEM images of the obtained PP-based films show that the fiber diameter is 1-7 μm and contains a rich air pore structure.

[0025] (S2) Preparation of SiO2 dispersion: SiO2 nanoparticles with an average particle size of 200 nm were dispersed in deionized water, and 0.1 wt% polyvinyl alcohol (PVA) was added as a dispersant to obtain a dispersion concentration of 5 wt%. The dispersion was treated with ultrasound at 40 kHz and 200 W for 60 min to obtain a stable SiO2 dispersion.

[0026] (S3) Pretreatment of PP base film: The PP base film was ultrasonically cleaned with ethanol and deionized water in sequence (30kHz, 100W, 10min), and then vacuum dried at 60℃ for 2h.

[0027] (S4) SiO2 nanoparticle deposition: The pretreated PP base film is immersed in SiO2 dispersion and treated under ultrasonic conditions of 40kHz and 200W for 90min to make SiO2 nanoparticles uniformly deposited on the fiber surface.

[0028] (S5) Post-treatment: After deposition, the film was rinsed three times with deionized water and vacuum dried at 60℃ for 4 hours to obtain a SiO2-modified PP-based film. Figure 4 As shown, the SEM image reveals that SiO2 nanoparticles randomly cover the fiber surface, such as... Figure 5 As shown, XRD analysis confirmed the SiO2 crystal structure, thus confirming that SiO2 nanoparticles have covered the surface of PP fibers.

[0029] (S6) Multilayer lamination: A water-based polyurethane adhesive (0.1 g / m²) is sprayed onto the surface of a PP / SiO2 membrane on one side, and a TPU microporous membrane with a thickness of 30 μm is laminated (waterproof performance 15,000 mm water pressure, air permeability 12,000 g / m² / 24h). The same adhesive is sprayed onto the other side, and a CNT film with a thickness of 80 μm (surface resistivity 10 Ω / sq) is laminated. Hot-pressing lamination conditions are 90℃, 0.6 MPa, and 10 s, to obtain a composite textile with a total thickness of 230 μm.

[0030] The resulting composite textile was tested at an ambient temperature of 37℃ and a solar radiation intensity of 950 W / m². Figure 6 As shown, the results indicate that the surface temperature on one side of the TPU microporous membrane is about 5.3°C lower than the ambient temperature, exhibiting good radiative cooling effect; the temperature on the other side of the CNT film is about 46.5°C higher than the ambient temperature, demonstrating excellent thermal insulation performance. Example 2

[0031] This invention discloses a composite textile that combines passive radiative cooling and heat preservation functions, and its preparation method includes the following steps: (S1) PP Substrate Preparation: PP granules with a melt flow index of 1200 g / 10 min were selected. The melt-blowing process parameters were: melting temperature 250℃, 0.3 mm spinneret, and hot air stretching speed 35 m / s. A PP base film with a thickness of 100 μm and a porosity of 90% was collected. The PP base film was hot-pressed at 130℃ and 0.5 MPa for 0.5 min. Figure 7 As shown, the SEM image reveals that the fiber diameter is finer than the pore structure in Example 1.

[0032] (S2) Preparation of SiO2 dispersion: SiO2 nanoparticles with an average particle size of 300 nm were dispersed in deionized water, and 0.05 wt% polyacrylic acid (PAA) was added as a dispersant to obtain a dispersion concentration of 2 wt%. The dispersion was treated under ultrasonic conditions of 50 kHz and 150 W for 45 min to obtain a uniform dispersion.

[0033] (S3) Pretreatment of PP base film: Same as in Example 1, clean and dry.

[0034] (S4) SiO2 nanoparticle deposition: The pretreated PP base film was immersed in SiO2 dispersion and treated under ultrasonic conditions of 50kHz and 150W for 60min to deposit SiO2 nanoparticles.

[0035] (S5) Post-treatment: Rinse three times, then vacuum dry at 60℃ for 3 hours. Figure 8 As shown in the SEM image, the SiO2 particles are uniformly distributed, as... Figure 9 As shown, EDS analysis confirmed the presence of Si and O elements.

[0036] (S6) Multilayer Composite: A water-based polyurethane adhesive (0.08 g / m²) is sprayed onto a PP / SiO2 membrane on one side, and a TPU microporous membrane with a thickness of 20 μm is laminated on it (waterproof performance 12,000 mm water pressure, air permeability 14,000 g / m² / 24h). A CNT film with a thickness of 50 μm (surface resistivity 15 Ω / sq) is laminated on the other side, and the hot pressing conditions are 85℃, 0.7 MPa, and 12 s, to obtain a composite textile with a total thickness of 170 μm.

[0037] Performance testing: The resulting composite textile was tested under the same conditions as in Example 1, i.e., at an ambient temperature of 37°C and a solar radiation intensity of 950 W / m². Figure 10 As shown, the results indicate that at noon, the surface temperature of the TPU microporous membrane side is about 5.1℃ lower than the ambient temperature, exhibiting a good radiative cooling effect; the temperature of the CNT film side is about 45.2℃ higher than the ambient temperature, demonstrating excellent thermal insulation performance. Example 3

[0038] This invention discloses a composite textile that combines passive radiative cooling and heat preservation functions, and its preparation method includes the following steps: (S1) Preparation of PP substrate: PP granules with a melt flow index of 800 g / 10 min were selected. The melt-blowing process parameters were: melting temperature 270℃, 0.3 mm spinneret, and hot air stretching speed 25 m / s. A PP base film with a thickness of 150 μm and a porosity of 80% was formed. The PP base film was hot-pressed at 130℃ and 0.3 MPa for 1.5 min. SEM images showed that the fiber diameter was 3-6 μm.

[0039] (S2) Preparation of SiO2 dispersion: SiO2 nanoparticles with an average particle size of 500 nm were dispersed in deionized water, and 0.2 wt% polyvinyl alcohol (PVA) was added to obtain a dispersion concentration of 8 wt%. The dispersion was treated under ultrasonic conditions of 30 kHz and 300 W for 120 min to obtain a stable dispersion.

[0040] (S3) Pretreatment of PP base film: Same as in Example 1, clean and dry.

[0041] (S4) SiO2 nanoparticle deposition: The pretreated PP base film was immersed in SiO2 dispersion and treated under ultrasonic conditions of 30kHz and 300W for 120min to deposit SiO2 nanoparticles.

[0042] (S5) Post-treatment: Rinse 3 times and then vacuum dry at 60℃ for 4 hours.

[0043] (S6) Multilayer composite: A water-based polyurethane adhesive (0.12 g / m²) is sprayed onto one side, and a 50 μm thick TPU microporous membrane is laminated (waterproof performance 20,000 mm water pressure, air permeability 10,000 g / m² / 24h, SEM image see...). Figure 11 On the other side, a 100 μm thick CNT film was laminated (surface resistivity 5 Ω / sq, SEM image see [image details]). Figure 12 A composite textile with a total thickness of 300 μm was prepared by hot pressing at 100℃, 0.8 MPa, and 8 s.

[0044] Test Analysis: The cumulative WVTR of the composite textile prepared in this embodiment is approximately 0.36 g·cm³ over 90 hours. -2 , with natural cotton (approximately 0.38g·cm -2 This indicates that it has excellent breathability and moisture transfer capabilities, such as... Figure 13 As shown in the image. A photograph of the composite film prepared in this embodiment is shown below. Figure 14As shown, the TRU microporous membrane's radiative cooling side is milky white, while the CNT film side is black. Test results show that the average reflectance of the radiative cooling side in the 0.3-2.5 μm solar spectrum is 96.5%, while the average reflectance of the CNT film side is 18.9%. Figure 15 As shown, they exhibit high solar reflectance and absorption characteristics, consistent with the actual appearance. Further testing revealed that the emissivity of the radiative cooling side in the 8-13 μm atmospheric window is 0.948, and the emissivity of the CNT thin film layer side is 0.318, as... Figure 16 As shown, the radiative cooling side exhibits excellent atmospheric window radiation capability, while the CNT film layer effectively suppresses thermal radiation. Tests were conducted at an ambient temperature of 37°C and a solar irradiance of 950 W / m². The results show that at noon, the surface temperature of the TPU microporous membrane side is approximately 5.6°C lower than the ambient temperature, demonstrating good radiative cooling; the temperature of the CNT film side is approximately 47.1°C higher than the ambient temperature, exhibiting excellent thermal insulation performance, thus achieving significant radiative cooling and thermal insulation effects respectively. These performance characteristics are consistent with the dual-function mechanism of radiative cooling and thermal insulation of this invention. Example 4

[0045] This invention discloses a composite textile that combines passive radiative cooling and heat preservation functions, and its preparation method includes the following steps: (S1) Preparation of PP substrate: PP granules with a melt flow index of 1500 g / 10 min were selected and extruded through a 0.3 mm diameter spinneret at a melting temperature of 240 °C using a melt-blowing process. After hot air stretching, the PP substrate was collected to form a 100 μm thick PP base film. The obtained PP base film was hot-pressed at 130 °C and 0.3 MPa for 0.5 min.

[0046] (S2) Preparation of SiO2 dispersion: SiO2 nanoparticles with an average particle size of 100 nm were dispersed in deionized water to prepare a dispersion with a concentration of 0.5 wt%, and treated under ultrasonic conditions of 30 kHz and 100 W for 30 min.

[0047] (S3) Pretreatment of PP base film: The PP base film is washed with ethanol and deionized water in sequence and dried at 60°C for 2 hours.

[0048] (S4) SiO2 nanoparticle deposition: The pretreated PP base film was immersed in the above dispersion and treated under ultrasonic conditions of 30kHz and 100W for 30min.

[0049] (S5) Post-treatment: Take out the membrane material, rinse it three times with deionized water, and dry it at 60°C for 4 hours to obtain SiO2 modified PP base membrane.

[0050] (S6) Multilayer lamination: A commercially available polyurethane spray adhesive is sprayed onto one side of a SiO2-modified PP base film, and a 20μm thick TPU microporous membrane (waterproof performance 10,000 mm water pressure, air permeability 15,000 g / m² / 24h) is laminated thereon. A 50μm thick CNT film (surface resistivity 20Ω / sq) is laminated thereon on the other side. The composite is hot-pressed at 80℃ and 0.5MPa for 15s to obtain a composite textile with a total thickness of approximately 150μm. Example 5

[0051] This invention discloses a composite textile that combines passive radiative cooling and heat preservation functions. Its preparation method is basically the same as that in Example 4, except that: (S1) The melt flow index of PP granules is 800 g / 10 min, the melting temperature is 270℃, the thickness of PP base film is 150 μm, and the hot pressing conditions are 130℃, 0.5 MPa, and 1.5 min. (S2) SiO2 particles with a diameter of 500 nm were used to obtain a dispersion with a concentration of 10 wt%, which was ultrasonicated at 50 kHz, 300 W, and for 120 min. (S6) The TPU microporous membrane is 50μm thick (waterproof at 20,000 mm water pressure, breathable at 10,000 g / m² / 24h), the CNT film is 100μm thick (surface resistance 5Ω / sq), and the hot pressing conditions are 100℃, 0.8MPa, 8s, resulting in a composite textile with a total thickness of approximately 300μm.

[0052] like Figure 17 As shown, performance tests indicate that the average infrared emissivity of the radiative cooling side of the product in Example 4 is approximately 0.90 in the 8-13 μm band, and the average solar reflectivity is approximately 0.80 in the 0.3-2.5 μm band; the average infrared emissivity of the radiative cooling side of the product in Example 5 is approximately 0.98 in the 8-13 μm band, and the average solar reflectivity is approximately 0.95 in the 0.3-2.5 μm band. These results demonstrate that, within the process parameters defined in this invention, composite textiles possessing both passive radiative cooling and thermal insulation functions can be obtained.

Claims

1. A method for preparing a composite textile with both passive radiative cooling and heat preservation functions, characterized in that, Includes the following steps: (1) PP granules are melt-extruded and hot-air stretched using a melt-blown process to form a high-porosity PP base film, which is then dried. (2) SiO2 nanoparticles were dispersed in deionized water and a stable dispersion was obtained by ultrasonic treatment. (3) The PP base film is pretreated by cleaning and drying; (4) The PP base film is immersed in SiO2 dispersion, and SiO2 nanoparticles are deposited on the fiber surface by ultrasonic treatment; (5) The PP / SiO2 membrane after deposition is rinsed and dried to obtain a SiO2-modified PP base membrane; (6) Different functional films are laminated on both sides of the SiO2-modified PP base film: a thermoplastic TPU microporous film is laminated on one side and a CNT film is laminated on the other side, and a composite textile is obtained by hot pressing.

2. The preparation method according to claim 1, characterized in that, The PP granules have a melt flow index of 800-1500 g / 10 min and a melting temperature of 240-270℃. They are extruded through a 0.3 mm diameter spinneret and collected under hot air stretching to form a base film with a thickness of 100-150 μm.

3. The preparation method according to claim 1, characterized in that, In step (1), the PP base film is hot-pressed at 130℃ and 0.3-0.5MPa for 0.5-1.5min.

4. The preparation method according to claim 1, characterized in that, The SiO2 nanoparticles have an average particle size of 100-500 nm and a dispersion concentration of 0.5-10 wt%.

5. The preparation method according to claim 1, characterized in that, The deposition step in step (4) uses an ultrasonic frequency of 30-50kHz, a power of 100-300W, and a time of 30-120min.

6. The preparation method according to claim 1, characterized in that, The TPU microporous membrane has a thickness of 20-50μm, a waterproof performance of 10,000-20,000mm water pressure, and a breathability of 10,000-15,000g / m² / 24h.

7. The preparation method according to claim 1, characterized in that, The CNT film has a thickness of 50-100 μm and a surface resistivity of 5-20 Ω / sq.

8. The preparation method according to claim 1, characterized in that, Step (6) Hot pressing composite conditions are temperature 80-100℃, pressure 0.5-0.8MPa, time 8-15s, and spray adhesive is used in the composite process.

9. A composite textile prepared by the preparation method according to any one of claims 1-8, characterized in that, The total thickness of the composite textile is 150-300 μm.

10. The composite textile according to claim 9, characterized in that, The infrared emissivity in the 8-13μm band is 0.90-0.98, and the solar reflectivity in the 0.3-2.5μm band is 0.80-0.95.

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