Cooling fiber and fabric preparation method

Abstract

This invention discloses a method for preparing cooling fibers and fabrics, comprising the following steps: (1) pre-drying a first polymer and nanoparticles and dispersing them in a mixed solvent to obtain an electrospinning solution, and then performing electrospinning to obtain a first fiber membrane; (2) using melt differential electrospinning to prepare a second fiber membrane from a pre-dried second polymer; (3) attaching the second fiber membrane to the surface of a fabric, and then attaching the first fiber membrane to the surface of the second fiber membrane to obtain the product. Compared with conventional commercial fabrics, the cooling fabric prepared by this invention has superior solar reflectivity and mid-infrared emissivity, which can lower the skin temperature of the human body under direct sunlight and improve the thermal comfort of the human body under sunlight. This invention uses solution electrospinning and melt differential electrospinning technologies, which have low technical costs, high material conversion rates, and the potential for large-scale preparation, enabling commercial production.

Description

Technical Field

[0001] This invention relates to the field of functional textiles, and more specifically to a method for preparing cooling fibers and fabrics. Background Technology

[0002] Passive radiative cooling transfers heat released from Earth's surface to near-absolute zero in outer space via radiative heat exchange. Compared to traditional active cooling methods, passive radiative cooling offers the advantages of being energy-efficient, environmentally friendly, and sustainable. The complex composition of the atmosphere, including H2O, O3, CO2, and clouds, significantly absorbs, scatters, and reflects electromagnetic waves, hindering radiative heat exchange between Earth's surface and outer space and the upper atmosphere. Only during "atmospheric windows" can electromagnetic waves penetrate the atmosphere and transfer heat to space. Due to the combined effects of various atmospheric components, atmospheric radiation is relatively low in the 8-13 μm band, while atmospheric transmittance is also relatively high and stable. Therefore, this band is often referred to as the "first atmospheric window" and has significant thermodynamic application value.

[0003] Human skin is an excellent infrared emitter, with its emission wavelength largely overlapping with the "atmospheric window" band. In a non-moving state, approximately 60% of the body's total heat loss is dissipated through radiation. Clothing plays a crucial role in regulating personal thermal comfort in different environments. However, traditional textile designs, mostly based on heat conduction and convection, inevitably block the transmission of human body heat radiation, reducing the skin's heat dissipation effect. Therefore, applying radiative cooling technology to the textile field is a promising method for outdoor human cooling. This invention designs a nanostructured fiber and its fabric with high "atmospheric window" emissivity and high solar spectral reflectivity, which exhibits a significant passive cooling effect. Summary of the Invention

[0004] To overcome the problems of traditional textiles, this invention, based on the principle of electrospinning, produces a fiber membrane with a mesh structure possessing high infrared emissivity and solar reflectivity. This invention uses polypropylene, polyethylene, polylactic acid, polyvinylidene fluoride-hexafluoropropylene, polyvinyl chloride, polyethyl methacrylate, polyacrylonitrile, polystyrene, polybenzimidazole, and polyetheretherketone as fiber raw materials, and adds nanoparticles with high refractive index and low extinction coefficient in the solar spectrum, with a size of 0.02-50 μm, including ZnO, ZnO2, ZnS, CaF2, CaCO3, and SiO2. x One or more of the following are used: mica, rare earth silicates, molybdate nanoparticles, Al2O3, TiO2, BaSO4, Fe2O3, CuO, PbCO3, MgCO3, MgO, BN, and Y2O3. Finally, cooling fabrics with multi-layer composite structures are produced by spinning, weaving, and lamination.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of this invention provides a method for preparing cooling fibers and fabrics, comprising the following steps:

[0007] (1) The first polymer and nanoparticles are pre-dried and dispersed in a mixed solvent to obtain an electrospinning solution, and then electrospinning is performed to obtain a first fiber membrane;

[0008] (2) The pre-dried second polymer was used to prepare a second fiber membrane by melt differential electrospinning;

[0009] (3) The second fiber membrane is attached to the surface of the fabric, and then the first fiber membrane is attached to the surface of the second fiber membrane to obtain the product.

[0010] Preferably, the thickness of the first fiber membrane is 100-200 μm, and the thickness of the second fiber membrane is 100-200 μm.

[0011] Preferably, in step (1), the first polymer and nanoparticles are pre-dried in a vacuum drying oven at 40-60°C for 1.5-2.5 hours to remove moisture absorbed from the atmosphere, which can improve the film quality and make the particles uniformly dispersed.

[0012] Preferably, the first polymer is at least one of polyvinyl chloride, polyethyl methacrylate, polyacrylonitrile, polystyrene, polyvinylidene fluoride-hexafluoropropylene, polybenzimidazole, and polyetheretherketone.

[0013] Preferably, the nanoparticles include ZnO, ZnO2, ZnS, CaF2, CaCO3, and SiO2. x The nanoparticles are selected from at least one of the following: mica, rare earth silicate, molybdate nanoparticles, Al2O3, TiO2, BaSO4, Fe2O3, CuO, PbCO3, MgCO3, MgO, BN, and Y2O3; the nanoparticles have a particle size of 0.02-50 μm.

[0014] Preferably, the mass ratio of the first polymer to the nanoparticles is 1:(0.5-1.5).

[0015] Preferably, in step (1), the mixed solvent is a mixed solution of acetone and an organic solvent; the mass ratio of acetone to organic solvent is 1:(1-2); the organic solvent is at least one of dimethylacetamide, dimethylformamide, dimethyl sulfoxide, ethyl dimethylcarbamate, trimethylamine, trimethyl phosphate, acrylonitrile, and tetrahydrofuran.

[0016] Preferably, in step (1), the dried first polymer and nanoparticles are dispersed in a mixed solvent and magnetically stirred at 40-60°C for 6-8 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0017] Preferably, in step (1), the parameters of electrospinning are: spinning voltage of 15-25kV, injection pump speed of 1-7ml / h, spinning distance of 10-25cm, needle inner diameter of 0.2mm, roller speed of 500-700r / min, temperature of 20-30℃, humidity of 30%-60%, and spinning time of 1.5-2.5h.

[0018] Preferably, the second polymer is at least one of polylactic acid, polypropylene, and polytetrafluoroethylene.

[0019] Preferably, in step (2), the second polymer is pre-dried in a vacuum drying oven at 40-60°C for 1.5-2.5 hours to remove moisture absorbed from the atmosphere, which can improve the film quality.

[0020] Preferably, the melt differential electrospinning parameters are as follows: nozzle temperature is set to 150-250℃, screw speed is 1-20r / min, spinning voltage is 40-55kV, air flow rate is 100-200L / min, spinning distance is 10-22cm, and roller speed is 500-700r / min.

[0021] In some specific embodiments of the present invention, the fabric mentioned in step (3) is a common fabric on the market, such as wool fabric, cotton fabric, nylon fabric, silk fabric, polyester fabric, polylactic acid fabric, polyethylene fabric, etc.

[0022] The present invention does not limit the bonding method between the first fiber membrane and the fabric, or between the second fiber membrane and the first fiber membrane; adhesive or lamination can be used for bonding.

[0023] A second aspect of the present invention provides a cooling fiber and fabric, which are prepared by the aforementioned cooling fiber and fabric preparation method.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. Excellent performance: Compared with conventional commercial fabrics, the fabric prepared by this invention has a better solar reflectivity and mid-infrared emissivity, which can lower the skin temperature of the human body under direct sunlight and improve the thermal comfort of the human body under sunlight.

[0026] 2. Simple manufacturing method: Compared with conventional passive radiation cooling coatings that require complex and expensive processing equipment, such as nanoimprinting, electron beam evaporation, and atomic layer deposition, to prepare nanomaterials or composite materials with specific structures and optical properties, this invention uses solution electrospinning and melt differential electrospinning technology, which has low technical cost, high material conversion rate, and potential for large-scale preparation, enabling commercial production.

[0027] 3. All materials used are industrial-grade, easy to obtain, and inexpensive. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the fabric structure of the present invention;

[0029] Figure 2 This is a photograph of a fabric sample from Example 1 of the present invention;

[0030] Figure 3 This is a cooling effect diagram of Embodiment 1 of the present invention, where no coating indicates that the fabric does not have the first and second fiber membranes, and a coating indicates that the fabric has the first and second fiber membranes. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0033] Example 1

[0034] 1. Weigh out polyvinyl chloride, polypropylene, and ZnO nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0035] 2. Weigh 9.6g of dimethylacetamide and 14.4g of acetone into a beaker, add 8g of polyvinyl chloride and 8g of ZnO nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50℃ for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0036] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 20kV, injection pump speed 4mL / h, spinning distance 21cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0037] 4. Weigh 40g of polypropylene and use a melt differential electrospinning device to prepare the second fiber membrane. Set the nozzle temperature to 230℃, the screw speed to 4r / min, the spinning voltage to 53kV, the air flow rate to 150L / min, the spinning distance to 18cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0038] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the nylon fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0039] Figure 3 This is a diagram illustrating the cooling effect of Example 1. Figure 3 It can be seen that, compared with uncoated fabric, multi-layer composite cooling fabric can achieve an average temperature reduction of 6℃, with the maximum temperature difference reaching 15℃, indicating that multi-layer composite cooling fabric has good cooling performance.

[0040] Example 2

[0041] 1. Weigh out polymethyl ethyl acrylate, polylactic acid, and ZnO2 nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0042] 2. Weigh 9.6g of dimethylformamide and 14.4g of acetone into a beaker, add 8g of polyethyl methacrylate and 8g of ZnO2 nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50℃ for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0043] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 20kV, injection pump speed 4mL / h, spinning distance 21cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0044] 4. Weigh 40g of polylactic acid and use a melt differential electrospinning apparatus to prepare the second fiber membrane. Set the nozzle temperature to 220℃, the screw speed to 3r / min, the spinning voltage to 55kV, the blowing flow rate to 155L / min, the spinning distance to 15cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0045] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the wool fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0046] Example 3

[0047] 1. Weigh out polyacrylonitrile, polytetrafluoroethylene, and ZnS nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0048] 2. Weigh 9.6g of dimethylacetamide and 14.4g of acetone into a beaker, add 8g of polyacrylonitrile and 8g of ZnS nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50℃ for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0049] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 18kV, injection pump speed 4mL / h, spinning distance 20cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0050] 4. Weigh 40g of polytetrafluoroethylene and use a melt differential electrospinning device to prepare the second fiber membrane. Set the nozzle temperature to 230℃, the screw speed to 3r / min, the spinning voltage to 55kV, the blowing flow rate to 155L / min, the spinning distance to 15cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0051] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the nylon fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0052] Example 4

[0053] 1. Weigh out polystyrene, polypropylene, and CaF2 nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0054] 2. Weigh 9.6g of dimethylformamide and 14.4g of acetone into a beaker, add 8g of polystyrene and 8g of CaF2 nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50°C for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0055] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 20kV, injection pump speed 4mL / h, spinning distance 20cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0056] 4. Weigh 40g of polypropylene and use a melt differential electrospinning device to prepare the second fiber membrane. Set the nozzle temperature to 230℃, the screw speed to 4r / min, the spinning voltage to 53kV, the air flow rate to 150L / min, the spinning distance to 18cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0057] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the polylactic acid fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0058] Example 5

[0059] 1. Weigh out polybenzimidazole, polypropylene, and CaF2 nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0060] 2. Weigh 9.6g of dimethyl sulfoxide and 14.4g of acetone into a beaker, add 8g of polybenzimidazole and 8g of CaCO3 nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50℃ for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0061] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 22kV, injection pump speed 3mL / h, spinning distance 23cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0062] 4. Weigh 40g of polypropylene and use a melt differential electrospinning device to prepare the second fiber membrane. Set the nozzle temperature to 230℃, the screw speed to 4r / min, the spinning voltage to 53kV, the air flow rate to 150L / min, the spinning distance to 18cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0063] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the silk fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0064] Example 6

[0065] 1. Weigh out polyetheretherketone, polylactic acid, and SiO₂. x Nanoparticles were dried in a vacuum drying oven at 50°C for 2 hours.

[0066] 2. Weigh 9.6g of dimethyl sulfoxide and 14.4g of acetone into a beaker, add 8g of polyether ether ketone and 8g of ZnO2 nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50°C for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0067] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 20kV, injection pump speed 4mL / h, spinning distance 21cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, and needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0068] 4. Weigh 40g of polylactic acid and use a melt differential electrospinning apparatus to prepare the second fiber membrane. Set the nozzle temperature to 220℃, the screw speed to 3r / min, the spinning voltage to 55kV, the blowing flow rate to 155L / min, the spinning distance to 15cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0069] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the polyester fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0070] Example 7

[0071] 1. Weigh polyvinylidene fluoride-hexafluoropropylene, polylactic acid, and MgO nanoparticles, and dry them in a vacuum drying oven at 50°C for 2 hours.

[0072] 2. Weigh 9.6g of dimethylformamide and 14.4g of acetone into a beaker, add 8g of polyvinylidene fluoride-hexafluoropropylene and 8g of MgO nanoparticles, and place the beaker in a heat-collecting constant temperature magnetic stirrer. Stir magnetically at 50℃ for 7 hours to ensure uniform dispersion of the polymer and nanoparticles.

[0073] 3. Connect the tubing to the solution electrospinning apparatus to prepare the first fiber membrane. The spinning parameters are set as follows: spinning voltage 20kV, injection pump speed 3mL / h, spinning distance 20cm, spinning temperature 25℃, spinning humidity 40%, roller speed 700r / min, needle inner diameter 0.2mm. The spinning time is 2h, and the fiber membrane thickness is approximately 150μm. After spinning, the fiber membrane is peeled off and placed in a vacuum drying oven at 60℃ for 2h to remove residual solvent.

[0074] 4. Weigh 40g of polylactic acid and use a melt differential electrospinning apparatus to prepare the second fiber membrane. Set the nozzle temperature to 220℃, the screw speed to 3r / min, the spinning voltage to 55kV, the blowing flow rate to 155L / min, the spinning distance to 15cm, and the roller speed to 700r / min to obtain the second fiber membrane.

[0075] 5. Using 3M's multi-functional spray adhesive (SUPER77), the first fiber membrane, the second fiber membrane, and the polyethylene fabric are laminated together to obtain a multi-layer composite cooling fabric. The first fiber membrane provides excellent solar reflectivity, and the second fiber membrane provides excellent mid-infrared emissivity of 8-13μm.

[0076] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for preparing a cooling fabric, characterized in that, Includes the following steps: (1) The first polymer and nanoparticles are pre-dried and dispersed in a mixed solvent to obtain an electrospinning solution, and then electrospinned to obtain a first fiber membrane; the first polymer is at least one of polyvinyl chloride, polyethyl methacrylate, polyacrylonitrile, polystyrene, polyvinylidene fluoride-hexafluoropropylene, polybenzimidazole, and polyetheretherketone; the nanoparticles include ZnO, ZnO2, ZnS, CaF2, CaCO3, and SiO2. x The nanoparticles are selected from at least one of the following: mica, rare earth silicates, molybdate nanoparticles, Al2O3, TiO2, BaSO4, Fe2O3, CuO, PbCO3, MgCO3, MgO, BN, and Y2O3; the nanoparticles have a particle size of 0.02-50 μm; the mixed solvent is a mixture of acetone and an organic solvent; the mass ratio of acetone to organic solvent is 1:(1-2); the organic solvent is selected from at least one of dimethylacetamide, dimethylformamide, dimethyl sulfoxide, ethyl dimethylcarbamate, trimethylamine, trimethyl phosphate, acrylonitrile, and tetrahydrofuran. (2) A second fiber membrane is prepared by melt differential electrospinning of a pre-dried second polymer; the second polymer is at least one of polylactic acid, polypropylene, and polytetrafluoroethylene; (3) The second fiber membrane is attached to the surface of the fabric, and then the first fiber membrane is attached to the surface of the second fiber membrane to obtain the product.

2. The method for preparing cooling fabric according to claim 1, characterized in that, The thickness of the first fiber membrane is 100-200 μm, and the thickness of the second fiber membrane is 100-200 μm.

3. The method for preparing cooling fabric according to claim 1, characterized in that, In step (1), the mass ratio of the first polymer to the nanoparticles is 1:(0.5-1.5).

4. The method for preparing cooling fabric according to claim 1, characterized in that, In step (1), the parameters for electrospinning are as follows: spinning voltage is 15-25kV, injection pump speed is 1-7ml / h, spinning distance is 10-25cm, needle inner diameter is 0.2mm, roller speed is 500-700r / min, temperature is 20-30℃, humidity is 30%-60%, and spinning time is 1.5-2.5h.

5. The method for preparing cooling fabric according to claim 1, characterized in that, The parameters for melt differential electrospinning are as follows: nozzle temperature is set to 150-250℃, screw speed is 1-20r / min, spinning voltage is 40-55kV, air flow rate is 100-200L / min, spinning distance is 10-22cm, and roller speed is 500-700r / min.

6. A cooling fabric, characterized in that, It is prepared by the cooling fabric preparation method according to any one of claims 1-5.

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