阅读说明：本技术 一种湿法纺丝辐射制冷纤维、制备方法及其应用 (Wet spinning radiation refrigeration fiber, preparation method and application thereof ) 是由 陶光明 曾少宁 马耀光 于 2021-01-07 设计创作，主要内容包括：本发明公开了一种辐射制冷纤维、制备方法及其应用。本发明公开了一种辐射制冷纤维的制备方法,其包括下述步骤：将无机微纳颗粒和基底材料混合得到微纳颗粒和基底材料纺丝原液；将所述微纳颗粒和基底材料纺丝原液进行干湿法纺丝,得到辐射制冷纤维。使用上述方法制备,能够使纤维在具有优异辐射制冷性能的同时兼具良好的力学性能以及高舒适性,并且有效减少聚合物在纺丝过程中的降解量,提升纤维的综合性能。制备的辐射制冷纤维与织物具有高柔性,极大增强人体舒适感,且通过调控微纳颗粒的尺寸和浓度达到优异的辐射制冷效果,能编织成适用于人体皮肤表面降温的柔性织物,并且柔性织物8-13μm波段的平均发射率≥0.9,在太阳光波段的平均反射率≥0.9。(The invention discloses a radiation refrigeration fiber, a preparation method and application thereof. The invention discloses a preparation method of radiation refrigeration fiber, which comprises the following steps: mixing inorganic micro-nano particles and a substrate material to obtain a micro-nano particle and substrate material spinning solution; and carrying out dry-wet spinning on the micro-nano particles and the base material spinning solution to obtain the radiation refrigeration fiber. The fiber prepared by the method has excellent radiation refrigeration performance, good mechanical property and high comfort, effectively reduces the degradation amount of the polymer in the spinning process, and improves the comprehensive performance of the fiber. The prepared radiation refrigeration fiber and fabric have high flexibility, the comfort of a human body is greatly enhanced, the excellent radiation refrigeration effect is achieved by regulating the size and the concentration of micro-nano particles, the flexible fabric suitable for cooling the surface of the skin of the human body can be woven, the average emissivity of the flexible fabric in a wave band of 8-13 mu m is more than or equal to 0.9, and the average reflectivity of the flexible fabric in a solar wave band is more than or equal to 0.9.)

1. A preparation method of radiation refrigeration fiber comprises the following steps:

mixing inorganic micro-nano particles and a substrate material to obtain a micro-nano particle and substrate material spinning solution;

and carrying out dry-wet spinning on the micro-nano particles and the base material spinning solution to obtain the radiation refrigeration fiber.

2. The preparation method according to claim 1, wherein the base material is 1 to 999 parts by weight, preferably 1.5 to 4 parts by weight, and more preferably 2.33 to 3 parts by weight, based on 1 part by weight of the inorganic micro-nano particles.

3. The preparation method according to claim 1 or 2, wherein the inorganic micro-nano particles are selected from one or more of titanium dioxide, silicon dioxide, zinc oxide, silicon carbide, silicon nitride, zinc sulfide, aluminum oxide, iron oxide, boron nitride, magnesium oxide, barium sulfate, barium carbonate and aluminum silicate, and preferably are titanium dioxide, zinc oxide or silicon nitride.

4. The production method according to any one of claims 1 to 3, wherein the base material is one or more selected from the group consisting of cellulose, polylactic acid, polyethylene, polypropylene, polyamide, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, poly (benzamide), polyethylene terephthalate, chitosan, poly (paraphenylene terephthalamide), meta-aramid, polyvinylidene fluoride, dibutyryl chitin, polybenzimidazole, and polybenzobisoxazole, and preferably cellulose, polyacrylonitrile, polyvinyl alcohol, or chitosan.

5. The preparation method according to any one of claims 1 to 4, wherein the mixing of the inorganic micro-nano particles and the base material to obtain a micro-nano particle and base material spinning solution comprises adding the inorganic micro-nano particles and the base material into a solvent to obtain a micro-nano particle and base material spinning solution.

6. The method according to claim 5, wherein the solvent is selected from water, DMF, DMAc, nitric acid, acetic acid, toluene, cyclohexane, tetrahydrofuran-dioxane blend solution, benzene, carbon tetrachloride, amyl acetate, acetone, 4-methylmorpholine-N-oxide, N-ethylpyridine chloride, 1-butyl-3-methylimidazole chloride, 1-ethyl-3-methylimidazole chloride, 1-allyl-3-methylimidazole salt, 1-butyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole acetate, diethyl 1-ethyl-3-methylimidazole phosphate, NaOH/urea/water, NaOH/thiourea/urea/water, N-ethyl-3-methylimidazole, N, urea/caprolactam/NaOH/water, NaOH/ZnO/water, NaOH/ethanol/water, tetralin, naphthalene, mineral oil, paraffin oil, decahydronaphthalene and paraffin, preferably NaOH/urea/water, DMF, acetic acid or 4-methylmorpholine-N-oxide.

7. The preparation method according to any one of claims 1 to 6, wherein the inorganic micro-nano particles have a particle size of 0.03 to 25 μm, preferably 0.1 to 10 μm, and more preferably 0.4 μm.

8. The preparation method according to any one of claims 1 to 7, wherein the inorganic micro-nano particles and the base material account for 1 to 70 wt% of the spinning solution, preferably 20 to 40 wt%.

9. A radiation refrigerating fiber produced by the production method according to any one of claims 1 to 8.

10. A radiation refrigeration fabric obtained by weaving the radiation refrigeration fiber prepared by the preparation method of any one of claims 1 to 8 or the radiation refrigeration fiber of claim 9.

Technical Field

The invention relates to the technical field of radiation refrigeration, in particular to radiation refrigeration fiber, a preparation method and application thereof.

Background

The traditional space heat regulation and control system achieves the purpose of temperature regulation and control in a mode of heating and refrigerating the whole space, the process is usually accompanied with a large amount of energy consumption, and the energy waste and the environmental pollution problem caused by the process bring extremely adverse effects on human production and life. Refrigeration occupies a major part of the global power consumption, and such large refrigeration consumption poses a serious threat to human production economy. Therefore, by reducing the space cold requirement, the method not only can realize effective and economic personal comfort, but also has positive significance for the sustainable development of human beings.

The radiation refrigeration technology can enable an object to obtain high emissivity at 8-13 mu m and realize high reflectivity at a solar radiation waveband of 0.3-2.5 mu m through material selection and structure regulation, and the heat is effectively radiated and energy input is blocked by utilizing the spectrum selectivity regulation mode, so that the refrigeration purpose is achieved. Different from most of the existing refrigeration modes which need energy sources to take away heat, the radiation refrigeration does not need any power input, and has positive promotion effect on reducing global energy consumption and protecting environment.

The Stanford university team in 2013 theoretically designs a metal dielectric photon structure capable of realizing radiation refrigeration, and through the design of a nano optical material, the micro-nano structure of the periodic hole theoretically can realize passive refrigeration at the temperature of 40-60 ℃ lower than the ambient temperature, so that the passive refrigeration exceeding 100W/m is realized²Net cooling power. Then, the group prepares a photon radiation refrigerator integrating a solar reflector and a heat emitter by a micro-nano processing method, and realizes daytime radiation refrigeration for the first time. The photon radiation refrigerator is a multilayer film structure with a silver film as a substrate, and realizes strong selective emission of an atmosphere transparent window while reflecting 97% of solar radiation.

Since then, day-to-day radiant refrigeration systems designed by material selection and construction are drawing increasing attention. In 2017, there was a group at the university of colorado, usa, that prepared a random glass-polymer hybrid metamaterial with randomly distributed resonant dielectric SiO embedded in transparent polymer methylpentene₂Microspheres, and with a silver thin film as a backing, a 200nm silver coated backing made of a 50 μm thick metamaterial capable of reflecting about 96% of solar radiation, having a high emissivity of greater than 93% between 8-13 μm, and capable of generating greater than 100W [. sup.m ] m in direct sunlight^-2The radiant cooling power of. A teaching team of Yang and Yu of the university of Columbia in America prepares a P (VdF-HFP) graded porous coating based on a phase separation method, realizes high solar radiation reflectivity of 0.96 and high infrared emissivity of 0.97 through micro-nano pores in the coating, and can realize a passive refrigeration effect at the temperature lower than the ambient temperature and 6 ℃ in sunlight.

Although daytime passive radiation refrigeration has been achieved and achieves excellent cooling effects, the existing coating-state, film-state radiation refrigeration materials are not suitable for cooling human skin due to lack of necessary air and moisture permeability, softness and comfort. Therefore, there is a need to develop soft and comfortable fibrous textile-state radiation refrigeration materials to meet personal thermal comfort needs.

Chinese patent application CN110042564A proposes a radiation refrigeration fiber membrane and its preparation method and application. Radiation particles with good monodispersity are randomly dispersed among polymer fibers through electrostatic spinning, and the fiber membrane which is simple in structure and can be used for cooling a human body is prepared. The fiber membrane can ensure that the surface temperature of an object is 1.6-2.7 ℃ lower than the ambient temperature when the fiber membrane is tested in the sun, but the method has low production efficiency, complex process and high equipment cost, does not have knittability, has limited application scenes, and cannot prepare textiles for human body radiation refrigeration.

Chinese patent application CN202010261971.7 provides a design method of radiation refrigeration fiber and the radiation refrigeration fiber, FDTD entities based on a time domain finite difference method are utilized to construct a simulation model of doped medium micro-nano particles in a substrate material, the highest solar spectrum reflection efficiency under the same volume percentage is realized by accurately controlling the concentration and the size of a scattering medium, a complete design method is provided for the radiation refrigeration fiber, and the radiation refrigeration fiber is well compatible with the existing industrial technology.

The Chinese patent application CN202010261972.1 provides a preparation method of a high-doping radiation refrigeration composite fiber and a fabric thereof, wherein micro-nano particles are introduced into the fiber by a hot drawing method to prepare the fiber, and the fiber is woven into a fabric suitable for cooling a human body, so that high reflectivity of solar radiation and high emissivity of an atmospheric window are realized, and an excellent radiation refrigeration effect is achieved.

Chinese patent application CN202010261960.9 proposes a preparation method of radiation refrigeration fiber and fabric thereof, wherein inorganic micro-nano particles are introduced into polymer fiber by using a melt composite spinning method, so that the prepared fiber has excellent radiation refrigeration performance, and simultaneously has good mechanical property, elastic stability and high comfort, and the radiation refrigeration fabric suitable for cooling the surface of human skin is obtained.

The Chinese patent application CN202010261965.1 provides a radiation refrigeration function composite yarn and a preparation method of fabric thereof, high-concentration inorganic micro-nano particles are introduced outside and inside the yarn by using a padding method and a cladding method to prepare the radiation refrigeration composite yarn suitable for cooling human skin, and a textile with excellent radiation refrigeration performance and high comfort is obtained by a weaving technology, so that an effective method is provided for preparing the garment fabric with excellent radiation refrigeration performance. Therefore, based on the selection of the substrate material and the control of the particle size concentration of the micro-nano particles, the solar radiation energy input can be effectively blocked, the infrared radiation heat output is maximized, the radiation refrigeration performance is excellent, and the method is well compatible with the existing industrial technology.

Among many fiber preparation processes, dry-wet spinning fiber preparation is that a polymer is dissolved in a solvent to prepare a spinning solution with a proper concentration, the polymer is separated out into solid filaments through a coagulating bath after passing through a section of air layer, and the solid filaments are subjected to post-treatment processes such as stretching, sizing, washing, drying and the like. The process has the advantages that the high-viscosity spinning solution can be spun, so that the recovery and consumption of the solvent are reduced, the forming speed is high, the obtained fiber has a uniform structure, the cross section is approximately circular, the strength and the elasticity are improved, and the dyeability and the color are good. The physical change of the air layer is beneficial to forming fine and special, densified and homogenized filaments, and the structure forming process of the fibers can be effectively adjusted. The spun fiber has high density, smooth surface and no groove, can realize fast spinning, can be used for producing high-performance and high-quality fiber precursor, has high flexibility, greatly enhances the comfort of a human body, and is an ideal fiber for realizing the heat management of the human body.

CN101805934B discloses a cool viscose fiber, which is prepared by adding mica powder in an amount of 3-20 wt% of the dry basis weight of the fiber into a viscose fiber prepared from bamboo pulp as a raw material, and spinning by a dry-wet method. However, the fiber prepared by the dry-wet spinning method is limited to ultraviolet resistance, cannot regulate solar radiation and human body heat radiation, and cannot be used for personal heat management.

CN107955984A, chinese patent application, discloses a graphene grafted polysaccharide Lyocell fiber and a preparation method thereof, wherein cellulose, graphene grafted with polysaccharide and N-methylmorpholine-N-oxide (NMMO) aqueous solution are mixed to obtain a spinning stock solution containing graphene, and the Lyocell fiber prepared by dry-wet spinning has the advantages of excellent electrical conductivity and thermal conductivity, far infrared and ultraviolet prevention functions, good mechanical properties, and the like. However, the grafting steps involved in this method are complex and do not allow for the regulation of human radiation.

CN106498538B, a chinese patent, discloses a preparation method and application of a high thermal conductivity aromatic polyamide fiber, wherein graphene oxide is dispersed in an organic solvent to prepare a dispersion liquid; under the protection of inert gas, adding a m-phenylenediamine monomer into the dispersion liquid to be dissolved, so as to obtain a meta-aromatic polyamide resin solution; and spinning by adopting a dry-wet spinning process to finally prepare the high-thermal-conductivity aromatic polyamide fiber. However, the method has low production efficiency, complex process and high equipment cost, and cannot regulate and control human body radiation.

In summary, a method for preparing high-flexibility radiation refrigeration fibers in batches based on a dry-wet spinning process is lacking.

Disclosure of Invention

In order to solve the problems, the invention provides a dry-wet spinning radiation refrigeration fiber and a batch preparation method of a fabric thereof, which can introduce inorganic micro-nano particles by using a dry-wet spinning process and can accurately regulate and control the size of the micro-nano particles and the structure of the fiber.

According to the invention, dry-wet spinning is utilized, common polymer materials such as cellulose and the like are used as substrates, the radiation refrigeration fiber doped with inorganic micro-nano particles is prepared, the excellent mechanical property and radiation refrigeration effect are achieved by regulating the size and concentration of the micro-nano particles and the structure of the fiber, and the fiber is woven into the flexible fabric suitable for cooling the surface of human skin.

The specific technical scheme of the invention is as follows:

1. a preparation method of radiation refrigeration fiber comprises the following steps:

mixing inorganic micro-nano particles and a substrate material to obtain a micro-nano particle and substrate material spinning solution;

and carrying out dry-wet spinning on the micro-nano particles and the base material spinning solution to obtain the radiation refrigeration fiber.

2. The preparation method according to item 1, wherein the base material is 1 to 999 parts by weight, preferably 1.5 to 4 parts by weight, and more preferably 2.33 to 3 parts by weight, based on 1 part by weight of the inorganic micro-nano particles.

3. The preparation method according to item 1 or 2, wherein the inorganic micro-nano particles are selected from one or more of titanium dioxide, silicon dioxide, zinc oxide, silicon carbide, silicon nitride, zinc sulfide, aluminum oxide, iron oxide, boron nitride, magnesium oxide, barium sulfate, barium carbonate and aluminum silicate, and preferably are titanium dioxide, zinc oxide or silicon nitride.

4. The production method according to any one of items 1 to 3, wherein the base material is selected from one or more of cellulose, polylactic acid, polyethylene, polypropylene, polyamide, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, poly (benzamide), polyethylene terephthalate, chitosan, poly (paraphenylene terephthalamide), meta-aramid, polyvinylidene fluoride, dibutyryl chitin, polybenzimidazole, and polybenzobisoxazole, and is preferably cellulose, polyacrylonitrile, polyvinyl alcohol, or chitosan.

5. The preparation method according to any one of items 1 to 4, wherein the step of mixing the inorganic micro-nano particles and the base material to obtain the micro-nano particle and base material spinning solution comprises the step of adding the inorganic micro-nano particles and the base material into a solvent to obtain the micro-nano particle and base material spinning solution.

6. The production process according to item 5, wherein the solvent is selected from water, DMF, DMAc, nitric acid, acetic acid, toluene, cyclohexane, tetrahydrofuran-dioxane blend solution, benzene, carbon tetrachloride, amyl acetate, acetone, 4-methylmorpholine-N-oxide, N-ethylpyridine chloride, 1-butyl-3-methylimidazole chloride, 1-ethyl-3-methylimidazole chloride, 1-allyl-3-methylimidazol peaceful salt, 1-butyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole diethyl phosphate, NaOH/urea/water, NaOH/thiourea/urea/water, N-dimethyl-oxide, urea/caprolactam/NaOH/water, NaOH/ZnO/water, NaOH/ethanol/water, tetralin, naphthalene, mineral oil, paraffin oil, decahydronaphthalene and paraffin, preferably NaOH/urea/water, DMF, acetic acid or 4-methylmorpholine-N-oxide.

7. The preparation method according to any one of items 1 to 6, wherein the inorganic micro-nano particles have a particle size of 0.03 to 25 μm, preferably 0.1 to 10 μm, and more preferably 0.4 μm.

8. The preparation method according to any one of items 1 to 7, wherein the inorganic micro-nano particles and the base material account for 1 to 70 wt%, preferably 20 to 40 wt% of the spinning solution.

9. The preparation method according to any one of items 1 to 8, wherein the inorganic micro-nano particles comprise first inorganic micro-nano particles and second inorganic micro-nano particles; preferably, the first inorganic micro-nano particle and the second inorganic micro-nano particle are the same inorganic micro-nano particle or different inorganic micro-nano particles.

10. The production method according to item 9, wherein the base material includes a base material 1 and a base material 2, and preferably, the base material 1 and the base material 2 are the same base material or different base materials.

11. The preparation method according to item 10, wherein the first inorganic micro-nano particles and the base material 1 are mixed to form a first micro-nano particle and base material spinning dope; preferably, the base material 1 is 1 to 49 parts by weight, preferably 1.5 to 4 parts by weight, and more preferably 2.33 to 3 parts by weight, based on 1 part by weight of the first inorganic micro-nano particles;

preferably, the second inorganic micro-nano particles and the base material 2 are mixed to form second micro-nano particles and a base material spinning solution, and preferably, the second inorganic micro-nano particles are 0 or 1 part by weight of the second inorganic micro-nano particles, and the base material 2 is 4-49 parts by weight, preferably 9-19 parts by weight, and further preferably 10-12.5 parts by weight.

12. The preparation method according to the item 11, wherein the mass percentage of the first micro-nano particles and the base material in the spinning solution is 1-70%, preferably 20-40%;

preferably, the mass percentages of the second micro-nano particles and the base material in the spinning solution are 1-70%, preferably 20-40%.

13. The production method according to any one of items 1 to 12, wherein the dry-wet spinning includes the steps of:

the micro-nano particles and the base material spinning solution are sent to a spinning device, and then are sprayed out from spinneret holes of a spinneret in the spinning device to obtain a sprayed liquid;

the sprayed liquid enters the coagulating bath through an air layer to form nascent fiber;

and washing and stretching the nascent fiber to form the radiation refrigeration fiber.

14. The preparation method according to any one of items 1 to 13, wherein the viscosity of the micro-nano particles and the base material spinning solution is 50 to 400Pa · s, preferably 300Pa · s.

15. A radiation refrigerating fiber produced by the production method of any one of items 1 to 14.

16. The radiation refrigerating fiber according to item 15, wherein the structure of the radiation refrigerating fiber is at least one of a circular structure, a sheath-core structure, a hollow structure, a herringbone structure, a cross structure, a side-by-side structure, a radial structure, and a sea-island structure.

17. A radiation refrigeration fabric obtained by weaving the radiation refrigeration fiber prepared by the preparation method of any one of items 1 to 14 or the radiation refrigeration fiber of any one of items 15 to 16.

18. The radiation chilling fabric of item 17, wherein the radiation chilling fabric has an average reflectivity in the solar band of 0.9 or greater, preferably 0.9-0.95.

19. The radiation refrigerating fabric according to item 17, wherein the average emissivity of the radiation refrigerating fabric in the 8-13 μm band is 0.9 or more, preferably 0.90-0.95.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the invention, the radiation refrigeration fiber doped with inorganic micro-nano particles can be prepared by using a dry-wet spinning process, an excellent radiation refrigeration effect is achieved by regulating the size and concentration of the micro-nano particles, and the radiation refrigeration fiber is woven into a flexible fabric suitable for cooling the surface of human skin.

The average emissivity of the radiation refrigeration fabric prepared by the invention at the wave band of 8-13 μm is more than or equal to 0.9, and the average reflectivity at the wave band of sunlight is more than or equal to 0.9.

The preparation method can be used for designing the internal composite structure of the fiber, so that the fiber has excellent radiation refrigeration performance, good mechanical property and high comfort.

The invention adopts dry-wet spinning as a spinning process, can effectively reduce the degradation amount of the polymer in the spinning process and improve the comprehensive performance of the fiber. The prepared radiation refrigeration fiber and fabric have high flexibility, and the comfort of a human body is greatly enhanced.

The invention adopts a dry-wet spinning process, and can utilize natural materials such as cellulose, chitosan and the like as fiber substrate materials, so that the prepared cellulose fiber and fabric have good degradability, recoverability and green reproducibility.

Drawings

FIG. 1 is a schematic diagram of a Monte Carlo multilayer medium simulation model statistics-based model of the present invention;

FIG. 2 is a basic flow diagram of Monte Carlo multilayer media simulation based on the present invention;

FIG. 3 is a simulation diagram of the solar spectrum weighted reflectivity varying with particle size and thickness according to the present invention;

FIG. 4 is a schematic cross-sectional view of a radiation-cooled fiber prepared according to examples 1, 2, 3 and 4 of the present invention;

FIG. 5 is a schematic cross-sectional view of a radiation-cooled fiber prepared according to example 5 of the present invention;

FIG. 6 is a schematic cross-sectional view of a radiation-cooled fiber prepared according to example 6 of the present invention;

FIG. 7 is a schematic cross-sectional view of a radiation-cooled fiber prepared according to example 7 of the present invention;

FIG. 8 is a schematic diagram of an apparatus for dry-wet spinning according to an embodiment of the present invention;

fig. 9 is a schematic representation of a prepared radiation-cooled fiber of an embodiment of the present invention woven into a fabric.

Wherein, 1-spinning medicine pot; 2-an air layer; 3-coagulating bath; 4-heating roller; and 5, winding a silk roller.

Detailed Description

The present invention will be described in detail below. While specific embodiments of the invention have been shown, it should be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It should be noted that certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, various names may be used to refer to a component. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description which follows is a preferred embodiment of the invention, however, the description is given for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the present invention is defined by the appended claims.

The invention provides a preparation method of radiation refrigeration fiber, which comprises the following steps:

mixing inorganic micro-nano particles and a substrate material to obtain a micro-nano particle and substrate material spinning solution;

and carrying out dry-wet spinning on the micro-nano particles and the base material spinning solution to obtain the radiation refrigeration fiber.

The radiation refrigeration fiber has the radiation refrigeration function, and can discharge self heat to the outer space with the temperature close to absolute zero through an 'atmospheric window' in the form of 8-13 mu m electromagnetic wave so as to achieve the purpose of self cooling.

The inorganic micro-nano particles have the characteristic of high refractive index, can generate high scattering efficiency in a substrate material, can enable the radiation refrigeration fibers to have high solar radiation reflectivity, are selected from one or more of titanium dioxide, silicon dioxide, zinc oxide, silicon carbide, silicon nitride, zinc sulfide, aluminum oxide, iron oxide, boron nitride, magnesium oxide, barium sulfate, barium carbonate and aluminum silicate, and are preferably titanium dioxide, silicon dioxide, aluminum oxide and barium sulfate.

The substrate material has the characteristic of high infrared emissivity, and is selected from one or more than two of cellulose, polylactic acid, polyethylene, polypropylene, polyamide, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, poly-p-benzamide, polyethylene terephthalate, chitosan, poly-p-phenylene terephthamide, meta-aromatic polyamide, polyvinylidene fluoride, dibutyrylchitin, polybenzimidazole and polybenzobisoxazole, and preferably cellulose, polyacrylonitrile or chitosan.

In a preferred embodiment of the present invention, the base material is 1 to 49 parts by weight, preferably 1.5 to 4 parts by weight, and more preferably 2.33 to 3 parts by weight, based on 1 part by weight of the inorganic micro-nano particles.

For example, the base material may be 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.33 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 5 parts by weight, 10 parts by weight, 20 parts by weight, 49 parts by weight, or the like, based on 1 part by weight of the inorganic micro-nano particles.

In a preferred embodiment of the present invention, the inorganic micro-nano particles are selected from titanium dioxide (TiO)₂) Silicon dioxide (SiO)₂) Zinc oxide (ZnO), silicon carbide (SiC), silicon nitride (Si)₃N₄) Zinc sulfide (ZnS), aluminum oxide (Al)₂O₃) Iron oxide (Fe)₂O₃) Boron Nitride (BN), magnesium oxide (MgO), barium sulfate (BaSO)₄) Barium carbonate (BaCO)₃) And aluminum silicate (Al)₂SiO₅) One ofOr a mixture of two or more thereof, preferably titanium dioxide, zinc oxide or silicon nitride.

Preferably, the particle size of the inorganic micro-nano particles is 0.03-25 μm, preferably 0.1-10 μm, and more preferably 0.4 μm, for example, the particle size of the inorganic micro-nano particles is 0.03 μm, 0.05 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, or any range therebetween.

In a preferred embodiment of the present invention, the substrate material is selected from one or a mixture of two or more of cellulose, polylactic acid, polyethylene, polyimide, polypropylene, polyamide, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, poly-benzamide, polyethylene terephthalate, chitosan, poly-paraphenylene terephthalamide, meta-aromatic polyamide, polyvinylidene fluoride, dibutyryl chitin, polybenzimidazole and polybenzobisoxazole, and preferably is selected from cellulose, polyacrylonitrile, polyvinyl alcohol and chitosan.

Polylactic acid (PLA) is a polymer obtained by polymerizing lactic acid as a main raw material, is a novel biodegradable material, has good mechanical properties and physical properties, and has good tensile strength and extensibility.

Polyethylene (PE) is a thermoplastic resin obtained by polymerizing ethylene, has excellent low-temperature resistance, good chemical stability, and is resistant to most acid-base attacks (not to acids with oxidative properties).

Polypropylene (PP) is a polymer formed by propylene addition polymerization, can resist corrosion of acid, alkali, salt solution and various organic solvents at the temperature of below 80 ℃, can be decomposed at high temperature and under the action of oxidation, and is widely applied to the production of fiber products such as clothes and blankets, medical instruments, automobiles, bicycles, parts, conveying pipelines, chemical containers and the like, and is also used for packaging food and medicines.

Polyamide (PA) is commonly called Nylon (Nylon), is a general name of thermoplastic resin containing repeated amide groups- [ NHCO ] -, has good comprehensive performance including mechanical property, heat resistance, abrasion resistance, chemical resistance and self-lubrication, has low friction coefficient and certain flame retardance, is easy to process, is suitable for being filled with glass fiber and other fillers for reinforcing and modifying, improves the performance and expands the application range.

Polyvinyl chloride (PVC) is an initiator for vinyl chloride monomer (VCM for short) in the presence of peroxides, azo compounds, etc.; or polymers polymerized by a free radical polymerization mechanism under the action of light and heat are general plastics with the highest yield in the world and are widely applied. The product has wide application in building materials, industrial products, daily necessities, floor leathers, floor tiles, artificial leathers, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers and the like.

Polystyrene (PS) is a polymer synthesized from styrene monomer by free radical addition polymerization, has good thermal insulation and excellent optical properties, is an excellent electrical insulation material, and has good corrosion resistance.

Polyvinyl acetate (PVAC), also known as polyvinyl acetate, is a polymer of vinyl acetate (vinyl acetate).

Polyvinyl alcohol (PVA) is an important chemical raw material for manufacturing polyvinyl acetal, gasoline-resistant pipelines, vinylon synthetic fibers, fabric treating agents, emulsifiers, paper coatings, adhesives, glue and the like.

Polyacrylonitrile (PAN) is obtained by radical polymerization of acrylonitrile monomer, and has the advantages of good weather resistance and sun resistance, and can maintain 77% of original strength after being placed outdoors for 18 months, and also has resistance to chemical reagents, especially inorganic acid, bleaching powder, hydrogen peroxide and general organic reagents.

The method comprises the following steps of reacting poly-p-benzamide (PBA) for 3 hours in the presence of a catalyst and a cocatalyst and at a temperature of 80-90 ℃ by taking p-aminobenzoic acid as a unit and N-methylpyrrolidone as a solvent. Then, the material is precipitated into alcohol, the resin is washed by water and dried, and the resin poly-p-benzamide fiber for spinning, which is aromatic nuclear amide fiber with high strength, high modulus and low density, can be obtained.

Polyethylene terephthalate (PET) is prepared by exchanging dimethyl terephthalate with ethylene glycol or esterifying terephthalic acid with ethylene glycol to synthesize dihydroxy ethyl terephthalate, and then performing polycondensation reaction, belongs to crystalline saturated polyester, has excellent physical and mechanical properties in a wider temperature range, can reach 120 ℃ for long-term use, has excellent electrical insulation, and has good electrical properties even at high temperature and high frequency, but has poor corona resistance, creep resistance, fatigue resistance, friction resistance and dimensional stability.

The chitosan is a product of natural polysaccharide chitin with partial acetyl removed, has multiple physiological functions of biodegradability, biocompatibility, nontoxicity, bacteriostasis, cancer resistance, lipid reduction, immunity enhancement and the like, and is widely applied to the fields of food additives, textiles, agriculture, environmental protection, beauty and health care, cosmetics, antibacterial agents, medical fibers, medical dressings, artificial tissue materials, drug slow release materials, gene transduction carriers, biomedical fields, medical absorbable materials, tissue engineering carrier materials, medical treatment, drug development and the like and other daily chemical industries.

Poly-p-phenylene terephthamide (PPTA) is a fully p-polyaramid prepared by condensation polymerization of p-phenylene diamine and paraphthaloyl chloride, and has high heat resistance, high tensile strength, initial elastic modulus, stable thermal shrinkage and creep property, high insulating property and chemical corrosion resistance.

Poly (m-phenylene isophthalamide) (PMIA), also called meta-aramid, is a linear macromolecular structure formed by connecting amide groups with meta-phenyl groups, and PMIA has high content of benzene ring groups and is easy to form a ladder-shaped structure, so that the prepared fiber not only has excellent mechanical property, but also has good high-temperature resistance, and is widely applied to the fields of thermal protection clothing, filter materials, flame-retardant decorative cloth and the like.

Polyvinylidene fluoride (PVDF) mainly refers to vinylidene fluoride homopolymer or a copolymer of vinylidene fluoride and other small amount of fluorine-containing vinyl monomers, has the characteristics of fluororesin and general resin, and has special performances such as piezoelectricity, dielectricity, pyroelectricity and the like besides good chemical corrosion resistance, high temperature resistance, oxidation resistance, weather resistance and ray radiation resistance.

The polyimide-based polymer refers to a polymer having an imide ring (-CO-NH-CO-) in the main chain, and the polymer having a phthalimide structure is most important. Polyimide is used as a special engineering material and has been widely applied to the fields of aviation, aerospace, microelectronics, nano-scale, liquid crystal, separation membranes, laser and the like. The elastic modulus is second to that of carbon fiber, and the carbon fiber is used as a filter material and a bulletproof and fireproof fabric for high-temperature media and radioactive substances.

Dibutyryl chitin (DBCH) is a butyrylated chitin product obtained by a reaction under heterogeneous conditions with perchloric acid as a catalyst, and is easily soluble in common solvents such as acetone, DMF, ethanol and the like.

Polybenzimidazole is a benzo five-membered heterocyclic rigid chain polymer containing two nitrogen atoms, is generally prepared by condensation polymerization and cyclization of aromatic tetramine and diphenyl phthalate, and has excellent radiation resistance, boiling water resistance, solvent resistance and chemical resistance. The fiber fabric can be used as a high-temperature resistant adhesive and can be used for manufacturing high-performance composite materials, can be widely applied to the fields of aerospace, chemical machinery, oil exploitation, automobiles and the like, and can be used as a protective garment for preventing fire and atomic radiation.

The Polybenzobisoxazole (PBO) is a lyotropic liquid crystal heterocyclic polymer, and a macromolecular chain has high aromaticity, so that the polybenzobisoxazole has the excellent characteristics of high strength, high modulus, high temperature resistance, corrosion resistance and the like.

In a preferred embodiment of the present invention, the mixing the inorganic micro-nano particles and the base material to obtain the micro-nano particle and base material spinning solution includes adding the inorganic micro-nano particles and the base material into a solvent to obtain the micro-nano particle and base material spinning solution.

The solvent according to the present invention is not limited, and may be, for example, water, DMF, DMAc, nitric acid, acetic acid, toluene, cyclohexane, tetrahydrofuran-dioxane blend solution, benzene, carbon tetrachloride, amyl acetate, acetone, 4-methylmorpholine-N-oxide, N-ethylpyridine chloride, 1-butyl-3-methylimidazole chloride, 1-ethyl-3-methylimidazole chloride, 1-allyl-3-methylimidazole salt, 1-butyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazole diethyl phosphate, NaOH/urea/water, NaOH/thiourea/urea/water, tetrahydrofuran-dioxane blend solution, and acetic acid, NaOH/polyethylene glycol/water, NaOH/ZnO/water, NaOH/ethanol/water, tetrahydronaphthalene, naphthalene, mineral oil, paraffin oil, decalin and paraffin, preferably NaOH/urea/water, DMF, acetic acid or 4-methylmorpholine-N-oxide.

For the solvent of NaOH/urea/water, the solvent is formed by NaOH, urea and water, and the three solvents can be in any mass ratio, for example, the NaOH can be 8 percent, the urea can be 10 percent and the balance is water according to the mass percentage in the NaOH/urea/water solvent;

for the solvent of NaOH/thiourea/water, the solvent is formed by NaOH, thiourea and water, and the three solvents can be in any mass ratio, for example, the NaOH can be 8% and the thiourea can be 6.5% in terms of mass percentage in the NaOH/thiourea/water solvent, and the balance is water;

for the solvent of NaOH/thiourea/urea/water, which is a solvent formed by NaOH, thiourea, urea and water, the four solvents can be in any mass ratio, for example, the mass percentage of the NaOH/thiourea/urea/water solvent is 8%, the thiourea is 6.5%, the urea is 8%, and the balance is water;

for the solvent of urea/caprolactam/sodium hydroxide/water, which is a solvent formed by urea, caprolactam, sodium hydroxide and water, the ratio of the urea to the caprolactam to the sodium hydroxide to the water can be any mass ratio, for example, based on the mass percentage of the solvent of urea/caprolactam/sodium hydroxide/water, the ratio of urea to caprolactam can be 10%, the ratio of sodium hydroxide to water can be 8%, and the balance of water;

for the solvent of NaOH/ZnO/water, the solvent is formed by NaOH, ZnO and water, and the three solvents can be in any mass ratio, for example, the mass percentage of the NaOH/ZnO/water solvent is 8%, the mass percentage of the ZnO/water solvent is 10%, and the balance is water;

the solvent of NaOH/ethanol/water is a solvent formed by NaOH, ethanol and water, and the three solvents can be in any mass ratio, for example, the NaOH can be 8% by mass, the ethanol can be 10% by mass and the balance water is calculated by the mass percentage of the NaOH/ethanol/water solvent.

For the tetrahydrofuran-dioxane blend solution, which is a solution formed by tetrahydrofuran and dioxane, the volume ratio of tetrahydrofuran and dioxane is not limited in the present invention, and for example, the volume ratio may be 1: 1.

In a preferred embodiment of the present invention, the particle size of the inorganic micro-nano particles is 0.03 to 25 μm, preferably 0.1 to 10 μm, and more preferably 0.4 μm.

For example, the particle size of the inorganic micro-nano particles may be 0.03 μm, 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, and the like.

The particle size refers to: average diameter of inorganic micro-nano particles.

The particle size is determined by combining the Mie scattering theory with a Monte Carlo multilayer medium simulation model, and the specific operation method is shown as follows.

In a preferred embodiment of the present invention, the weight percentage of the micro-nano particles and the base material spinning solution is 1 to 70%, preferably 20 to 40%.

For example, the inorganic micro-nano particles and the base material may be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or any range therebetween, in terms of weight percentage of the micro-nano particles and the base material spinning solution.

In a preferred embodiment of the present invention, the inorganic micro-nano particles include a first inorganic micro-nano particle and a second inorganic micro-nano particle; preferably, the first inorganic micro-nano particle and the second inorganic micro-nano particle are the same inorganic micro-nano particle or different inorganic micro-nano particles;

preferably, the base material includes a base material 1 and a base material 2, and preferably, the base material 1 and the base material 2 may be the same base material or different base materials.

The different base materials need to use the same coagulation bath, i.e., a coagulation bath that coagulates both the clad layer described below and the core layer described below.

In a preferred embodiment of the present invention, wherein,

the first inorganic micro-nano particles and the substrate material 1 are mixed to form first micro-nano particles and a substrate material spinning solution, and the first micro-nano particles and the substrate material spinning solution finally form a core layer of the radiation refrigeration fiber.

Preferably, the base material 1 is 1 to 49 parts by weight, preferably 1.5 to 4 parts by weight, and more preferably 2.33 to 3 parts by weight, based on 1 part by weight of the first inorganic micro-nano particles;

preferably, the second inorganic micro-nano particles and the base material 2 are mixed to form second micro-nano particles and base material spinning solution, and the second micro-nano particles and the base material spinning solution finally form a cladding of the radiation refrigeration fiber.

The second inorganic micro-nano particles are 0 or 1 part by weight of the second inorganic micro-nano particles, and the base material 2 is 4-49 parts by weight, preferably 9-19 parts by weight, and more preferably 10-12.5 parts by weight.

For example, the base material 1 may be 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.33 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 5 parts by weight, 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 49 parts by weight, or the like, based on 1 part by weight of the first inorganic micro-nano particles.

The base material 2 may be 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 12.5 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 49 parts by weight, and the like, based on 1 part by weight of the second inorganic micro-nano particles.

The mass percentage of the second inorganic micro-nano particles in the cladding layer is less than or equal to the mass percentage of the first inorganic micro-nano particles in the core layer.

In a preferred embodiment of the present invention, the mass percentage of the first micro-nano particles and the base material spinning solution is 1-70%, preferably 20-40%;

preferably, the mass percentage of the second micro-nano particles and the base material spinning solution is 1-70%, preferably 20-40%.

For example, the first inorganic micro-nano particle and the base material 1 may be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or any range therebetween, in terms of mass percentage of the first micro-nano particle and the base material spinning solution;

the mass percentage of the second micro-nano particles and the base material spinning solution is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or any range therebetween;

in a preferred embodiment of the present invention, the dry-wet spinning comprises the following steps:

the micro-nano particles and the base material spinning solution are sent to a spinning device, and then are sprayed out from spinneret holes of a spinneret in the spinning device to obtain a sprayed liquid;

the sprayed liquid enters the coagulating bath through an air layer to form nascent fiber;

and washing and stretching the nascent fiber to form the radiation refrigeration fiber.

Preferably, the diameter of the spinneret orifice is 0.01-0.8mm, and the diameter of the fiber is 0.005-0.5 mm.

For example, the diameter of the spinneret orifice is 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or the like.

The spinning device of the present invention is not limited as long as it can perform spinning, and for example, the spinning device may be a spinning tank or a spinning box.

The spinning temperature is not limited in the present invention, and for example, the spinning temperature may be 10 to 150 ℃ and may be, for example, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃ or the like.

The spinning speed is not limited in the present invention, and for example, the spinning speed may be 0.6 to 3000m/min, for example, 0.6m/min, 1m/min, 10m/min, 50m/min, 100m/min, 500m/min, 1000m/min, 1500m/min, 2000m/min, 2500m/min, 3000m/min, or the like.

Preferably, the viscosity of the micro-nano particles and the base material spinning solution is 50-400Pa · s, preferably 300Pa · s, for example, the viscosity of the micro-nano particles and the base material spinning solution may be 50Pa · s, 100Pa · s, 150Pa · s, 200Pa · s, 250Pa · s, 300Pa · s, 350Pa · s, 400Pa · s, or the like.

The viscosity is measured by a viscometer known in the art, such as an NDJ-5S viscometer, an NDJ-8S viscometer or an NDJ-9S viscometer available from Shanghaineen technology.

Preferably, the length of the air layer is 2 to 500mm, for example, 2mm, 5mm, 10mm, 50mm, 100mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, etc

The length refers to the distance from the orifice to the coagulation bath.

Preferably, the temperature of the coagulation bath is 0-100 ℃, for example, 0 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃ and the like.

The number of coagulation baths is not limited in the present invention, and those skilled in the art can set the number of coagulation baths as needed, for example, the coagulation bath includes 2 coagulation baths, and preferably, the temperature of the coagulation bath i is equal to or higher than the temperature of the coagulation bath ii, and the coagulation bath i means that the coagulation bath into which the discharged liquid first enters after passing through the air layer is the coagulation bath i, and the coagulation bath into which the discharged liquid second enters again is the coagulation bath ii.

For the coagulation bath, the present invention is not limited, and for example, the solute of the coagulation bath may be water, dimethyl sulfoxide (DMSO), sulfuric acid (H)₂SO₄) Sodium sulfate (Na)₂SO₄) Amine sulfate ((NH)₄)₂SO₄)；

The mass percentage of solute in the coagulation bath may be 0-80%, for example, 0, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.

The invention provides a radiation refrigeration fiber which is prepared by the preparation method.

In a preferred embodiment of the present invention, the structure of the radiation refrigeration fiber is at least one of a circular structure, a sheath-core structure, a hollow structure, a herringbone structure, a cross structure, a side-by-side structure, a radial structure, and an island-in-sea structure.

The invention provides a radiation refrigeration fabric, which is prepared by the preparation method or is woven by the radiation refrigeration fiber.

The knitting may be knitting or weaving.

In a preferred embodiment of the present invention, the average reflectivity of the radiation refrigerating fabric in the solar wave band is greater than or equal to 0.9, preferably 0.9-0.95.

For example, the average reflectivity of the radiant cooling fabric in the solar band can be 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, etc.

In a preferred embodiment of the invention, the average emissivity of the radiation refrigerating fabric in the 8-13 μm wave band is greater than or equal to 0.9, preferably 0.90-0.95.

For example, the average emissivity of the radiation refrigerating fabric in the 8-13 μm wave band can be 0.90, 0.91, 0.92, 0.93, 0.94, 0.95 and the like

The invention provides a preparation method of a radiation refrigeration fabric, which comprises the following steps:

the radiation refrigeration fiber prepared by the preparation method or the radiation refrigeration fiber is used as warp and weft to be woven.

The further preferable particle size of the inorganic micro-nano particles is 0.4 mu m, which is determined by combining a meter scattering theory and a Monte Carlo multilayer medium simulation model, and the specific operation is as follows:

the core idea in determining the optimum particle size is that the reflectivity in the solar radiation band (0.3-2.5 μm) is maximized while maintaining the particle volume concentration.

In order to simplify the optimization process, the fabric woven by the radiation refrigeration fibers is equivalent to a parallel flat film, and the reflectivity of the cellulose film to the solar wave band is given according to Monte Carlo multilayer medium simulation and Mie scattering theory.

The Monte Carlo multilayer medium simulation model is a statistical model, the model to be simulated is shown in figure 1, and the flat film model has three characteristic parameters: equivalent scattering coefficient sigma_sλEquivalent absorption coefficient kappa_λAnd asymmetric parameter g, a large number of iterations (generally more than 1000 times) are required for simulation, a photon beam with unit energy is driven in each iteration (an arrow in fig. 1, the thickness represents energy, the length represents a propagation distance without scattering, and the direction represents a propagation direction), the photon beam enters the composite material after undergoing a specular reflection on the surface, the propagation process of propagation, absorption and scattering is started circularly, the propagation distance of the photon beam in the nth cycle is sn, the light beam is attenuated due to absorption in the propagation process, and after the propagation process of one time is finished, the photon beam changes the propagation direction due to scattering and enters the next cycle until the energy of the photon beam is completely absorbed or escapesAnd (6) forming a thin film structure. Finally, the reflection rate, the transmission rate and the absorption rate of the thin film medium can be obtained by recording and counting the energy reflected, transmitted and absorbed by the photon beam in each iteration process and calculating the arithmetic mean.

Further, the propagation distance of the nth cycle in the simulation

sn＝-ln(ξ₁)/σ_sλ

ξ₁Is a random number in the interval of 0-1.

Further, the photon energy absorbed during the propagation is

And E is the initial energy of the photon beam in the nth cycle.

Further, the deflection angle θ of the propagation direction of the photon beam in the (n + 1) th cycle is determined by the following equation

ξ₂Is a random number in the interval of 0-1.

Further, the azimuth angle φ of the n +1 th propagation direction is determined by the following equation

φ＝2πξ₃

ξ₃Is a random number in the interval of 0-1.

Wherein

κ_λ＝κ₀+π∫₀ ^∞Q_aR²n(R)dR

σ_sλ＝π∫₀ ^∞Q_sR²n(R)dR

In the formula

Where k is the imaginary part of the refractive index of the cellulose,d is the diameter of the titanium oxide particles, and lambda is the wavelength in vacuum.

Wherein m is₀Is the refractive index of cellulose, m₁In order to have a refractive index of titanium oxide,the number of the vacuum waves is the number of the vacuum waves,ψ_n、ξ_nis a Riccati-Bessel function.

The basic flow chart of the Monte Carlo multilayer medium simulation is shown in FIG. 2.

And calculating the reflectivity data of the equivalent flat plate film structures under different phases and volume concentrations, different thicknesses and different particle diameters by using the model, calculating the weighted reflectivity of each equivalent structure to solar radiation under a preset solar spectrum, and obtaining the optimal particle diameter of the micro-nano particles under different thicknesses according to the weighted reflectivity.

In the above step, the weighted reflectivity is:

wherein I_sun(λ) is the predetermined solar spectrum, λ 1 and λ 2 are the lower and upper limits, respectively, of the weighted wavelength range, and h is the thickness of the equivalent structure.

The predetermined range of the solar spectrum is 0.3-2.5 μm.

The scanning thickness range of the equivalent structure is 100-500 mu m

The scanning diameter range of the particles is 100-1000m

The obtained solar spectrum weighted reflectance was shown in FIG. 3 as a function of particle size and thickness, and the black curve in the graph is a reflectance contour line, and it can be seen that the weighted reflectance always obtained a maximum value at a particle size of 0.4 μm for different thicknesses, so that the optimum particle size of titanium oxide was determined to be 0.4. mu.m.

According to the invention, the radiation refrigeration fiber doped with inorganic micro-nano particles is prepared by a dry-wet spinning process, the excellent radiation refrigeration effect is achieved by regulating the size and concentration of the micro-nano particles, and the radiation refrigeration fiber is woven into a flexible fabric suitable for cooling the surface of human skin, and the preparation method can be used for designing the composite structure in the fiber, so that the fiber has excellent radiation refrigeration performance and good mechanical property and high comfort; by using the dry-wet spinning process, the degradation amount of the polymer in the spinning process can be effectively reduced, the comprehensive performance of the fiber is improved, and the prepared radiation refrigeration fiber and fabric have high flexibility and greatly enhance the comfort of a human body.

The average emissivity of the radiation refrigeration fabric prepared by the invention at the wave band of 8-13 μm is more than or equal to 0.9, and the average reflectivity at the wave band of sunlight is more than or equal to 0.9.

Examples

The invention is described generically and/or specifically for the materials used in the tests and the test methods, in the following examples,% means wt.%, i.e. percent by weight, unless otherwise specified. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially.

Example 1

Cellulose and TiO₂Preparing a spinning solution: 18000g of an aqueous solution of 7 wt.% NaOH/12 wt.% urea was prepared, 1600g of cellulose pulp and 400g of TiO dried in a vacuum oven at 100 ℃ for 24 hours₂Stirring the granules (diameter of 400nm) at 1500rpm for 30 min, centrifuging at 8000rpm and 10 deg.C for 10min to remove bubbles and insoluble substances to obtain cellulose and TiO₂10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: transferring the spinning stock solution into a spinning chemical tank through a metering pump and a candle filter, wherein the spinning temperature is 80 ℃, the spinning speed is 500m/min, and the spinning stock solution is sprayed out through a spinneret orifice with the diameter of 0.21mm at room temperature to 15 wt.% of H after passing through an air layer with the diameter of 50mm₂SO₄/10wt.％Na₂SO₄And/or water, wherein the temperature of the coagulating bath is 25 ℃, and the nascent fiber is obtained after stretching in the coagulating bath. Bundling, preheating bath drawing, boiling water or steam bath drawing, hot water washing at 60 ℃, oiling, drying densification, dry heat drawing, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigeration fiber, the screenshot of which is shown in figure 4, and then the radiation refrigeration fiber is collected on a winding roller under the condition of no drawing.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 20 wt.% of titanium dioxide particles, as shown in fig. 9.

Example 2

PAN and TiO₂Preparing a spinning solution: PAN polymerization of 1500gPreparing a spinning solution with the concentration of 7.2 wt.% by using 19305g of DMF as a solvent, strongly stirring until the solution is completely dissolved, and drying 645g of TiO in a vacuum oven at 100 ℃ for 24 hours₂Mixing the particles (diameter of 400nm) with the spinning solution, stirring at 90 deg.C for 7 hr, standing for defoaming for 9 hr to obtain PAN and TiO₂10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: transferring the spinning stock solution into a spinning medicine tank through a metering pump and a candle-shaped filter, wherein the spinning temperature is 90 ℃, the spinning speed is 1000m/min, then the spinning stock solution is sprayed out through a spinneret orifice with the diameter of 0.2mm, the spinning stock solution passes through an air layer with the diameter of 50mm, and then reaches a first coagulation bath (the concentration of DMSO is 70 wt.%) with the solute of DMSO at 25 ℃ and a second coagulation bath (the concentration of DMSO is 70 wt.%) with the solute of DMSO at 20 ℃, and then primary fibers are obtained after the coagulation bath stretching, the preheating bath stretching, the boiling water or steam bath stretching, the hot water washing at 50 ℃, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the primary fibers, so that radiation refrigeration fibers are obtained, the cross section of the radiation refrigeration fibers is shown in figure 4, and the obtained radiation refrigeration fibers are collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 30 wt.% of titanium dioxide particles, as shown in fig. 9.

Example 3

Chitosan and Si₄N₃Preparing a spinning solution: 1200g of chitosan, 18000g of 4 wt.% acetic acid aqueous solution as a solvent, preparing 6.25 wt.% spinning solution, strongly stirring until the chitosan is completely dissolved, drying 800g of Si in a vacuum oven at 100 ℃ for 24h₄N₃Particles (400 nm diameter) and spin solutionMixing the solutions, stirring for 7 hr, standing at 20 deg.C for defoaming to obtain chitosan and Si₄N₃10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 80 ℃, and the spinning speed is 1500 m/min. And then the fiber is sprayed out through a pinhole with the diameter of 0.21mm, the fiber passes through an air layer with the diameter of 40mm and then is put into a coagulating bath of 15 percent NaOH/30 percent absolute ethyl alcohol with the temperature of 25 ℃, primary fiber is obtained after the stretching of the coagulating bath, the stretching of the preheating bath, the stretching of boiling water or steam bath, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the primary fiber, radiation refrigeration fiber is obtained, the section of the radiation refrigeration fiber is shown in figure 4, and the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding the drawn-off fabric on a cloth roller, thereby obtaining the radiation refrigerating fabric uniformly doped with 40 wt.% silicon nitride particles, as shown in fig. 9.

Example 4

PVA and TiO₂Preparing a spinning solution: preparing a spinning solution with the concentration of 5.3 wt.% by using 18000g of DMF as a solvent for 1000g of PVA polymer, and drying 1000g of TiO in a vacuum oven at 100 ℃ for 24h₂Uniformly stirring particles (with diameter of 400nm) at 80 deg.C, standing the solution at 20 deg.C for defoaming to obtain PVA and TiO₂10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 80 ℃, and the spinning speed is 2000 m/min. Spraying from a spinneret plate with the diameter of 0.25mm, passing through an air layer with the diameter of about 10mm, entering into an absolute ethyl alcohol coagulating bath, and coagulating and forming at room temperature to obtain nascent fiber. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns by matching with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 50 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 5

Cellulose and TiO₂Preparing a spinning solution: 18000g of 4-methylmorpholine-N-oxide (NMMO) solvent was heated at 110 ℃ to completely melt, 1200g of cellulose pulp added with vigorous stirring and 800g of TiO dried in a vacuum oven at 100 ℃ for 24h₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The spinning dope, which is the first spinning dope, is 10 wt.% in the spinning dope.

Similarly, 10800g of NMMO solvent is heated at 110 ℃ to be completely melted, and 1200g of cellulose pulp is added under vigorous stirring to obtain a spinning solution in which the weight ratio of cellulose in the spinning solution is 10 wt.%, that is, a second spinning solution.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 40 wt.% of titanium dioxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by being matched with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 40 wt.% of titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 6

Cellulose and TiO₂Preparing a spinning solution: 18000g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated to be completely melted at 110 ℃, 1600g of cellulose pulp and 400g of TiO dried in a vacuum oven at 100 ℃ for 24h are added under vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a herringbone spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 6, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 20 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 7

Cellulose and TiO₂Preparing a spinning solution: 18000g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated to be completely melted at 110 ℃, 1600g of cellulose pulp and 400g of TiO dried in a vacuum oven at 100 ℃ for 24h are added under vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂10 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a cross spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulating bath at the temperature of 80 ℃ after passing through an air layer with the diameter of 50mm, and is stretched through the coagulating bath to obtain the nascent fiber. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 7, and the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 20 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 8

Cellulose and TiO₂Preparing a spinning solution: 8000g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated at 110 ℃ to be completely melted, 1500g of cellulose pulp and 500g of TiO dried in a vacuum oven at 100 ℃ for 24h are added under vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂20 wt.% of the spinning dope in the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 25 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 9

Cellulose and TiO₂Preparing a spinning solution: 2250g of 4-methylmorpholine-N-oxide (NMMO) solvent was heated to a complete melting at 110 ℃ and 1000g of cellulose pulp and 500g of TiO dried in a vacuum oven at 100 ℃ for 24h were added with vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂40 wt.% of the spinning dope in the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns by matching with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 30 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 10

Cellulose and TiO₂Preparing a spinning solution: 3267g of 4-methylmorpholine-N-oxide (NMMO) solvent were heated at 110 ℃ to completely melt, 1000g of cellulose pulp and 400g of TiO dried in a vacuum oven at 100 ℃ for 24h were added with vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂20 wt.% of the spinning dope in the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading away the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 28.6 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 11

Cellulose and Si₄N₃Preparing a spinning solution: heating 5000g of 4-methylmorpholine-N-oxide (NMMO) solvent at 110 deg.C to completely melt, adding 750g of cellulose pulp and 500g of Si dried in 100 deg.C vacuum oven for 24 hr under vigorous stirring₄N₃Particles (A)Diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and Si₄N₃20 wt.% of the spinning dope in the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigerating fabric uniformly doped with 40 wt.% silicon nitride particles, wherein the fabric is shown in figure 9.

Example 12

Cellulose and TiO₂Preparing a spinning solution: 3500g of 4-methylmorpholine-N-oxide (NMMO) solvent are heated to 110 ℃ for complete melting, 1200g of cellulose pulp and 300g of TiO dried in a vacuum oven at 100 ℃ for 24h are added with vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂30 wt.% of the spinning dope in the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 20 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 13

Preparation of cellulose and ZnO spinning dope: 4500g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated at 110 ℃ to be completely melted, 1000g of cellulose pulp and 500g of ZnO particles (the diameter is 400nm) dried in a vacuum oven at 100 ℃ for 24 hours are added under vigorous stirring, and the solution is placed at 20 ℃ for standing and defoaming to obtain 25 wt.% of spinning solution of cellulose and ZnO in the weight ratio of the spinning solution.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 500 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.2mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns in cooperation with other mechanisms on a weaving machine, and winding and leading away the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 33.3 wt.% of zinc oxide particles, wherein the fabric is shown in figure 9.

Example 14

Cellulose and TiO₂Preparing a spinning solution: 4950g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated at 110 deg.C to completely melt, 49g of cellulose pulp and 1g of TiO 10 μm particle size dried in a vacuum oven at 100 deg.C for 24 hr under vigorous stirring₂Granulating, standing at 20 deg.C for defoaming to obtain cellulose and TiO₂1 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 0.6 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.8mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns by matching with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 2 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 15

Cellulose and TiO₂Preparing a spinning solution: heating 3000g of 4-methylmorpholine-N-oxide (NMMO) solvent at 110 deg.C to completely melt, adding 3500g of cellulose pulp and 3500g of TiO with particle size of 0.1 μm, drying in a vacuum oven at 100 deg.C for 24 hr under vigorous stirring₂Granulating, standing at 20 deg.C for defoaming to obtain cellulose and TiO₂70 wt.% of the spinning dope.

Preparing radiation refrigeration fiber by dry-wet spinning: the spinning solution is transferred to a spinning chemical tank through a metering pump and a candle filter, the spinning temperature is 110 ℃, and the spinning speed is 3000 m/min. And the fiber is sprayed out through a spinneret orifice with the diameter of 0.01mm at room temperature, enters a water coagulation bath after passing through an air layer with the diameter of 50mm, the temperature of the coagulation bath is 80 ℃, and the nascent fiber is obtained after the nascent fiber is stretched through the coagulation bath. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the radiation refrigerating fiber, the section of the radiation refrigerating fiber is shown in figure 4, and then the obtained radiation refrigerating fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; and winding fibers on a shuttle as weft yarns, weaving the shuttle alternately through a shed channel in a reciprocating manner, adjusting the arrangement density of the weft yarns by matching with other mechanisms on a weaving machine, and winding and leading off the fabric on a cloth roller, thereby obtaining the radiation refrigeration fabric uniformly doped with 50 wt.% of titanium dioxide particles, wherein the fabric is shown in figure 9.

Example 16

Cellulose and TiO₂Preparing a spinning solution: 2800g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated at 110 ℃ to completely melt, 900g of cellulose pulp and 300g of TiO are added with vigorous stirring and dried in a vacuum oven at 100 ℃ for 24h₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The spinning dope, which is the first spinning dope, was 30 wt.% by weight in the spinning dope.

In a similar manner, 7700g NMMO solvent is heated at 110 deg.C to completely melt, 3000g cellulose pulp and 300g TiO are added under vigorous stirring and dried in a vacuum oven at 100 deg.C for 24h₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The second dope was a dope containing 30 wt.% of the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with 25 wt.% of titanium dioxide particles uniformly doped in the core layer and 9 wt.% of titanium dioxide particles uniformly doped in the skin layer, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 25 wt.% of titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 17

Cellulose and TiO₂Preparing a spinning solution: 2250g of 4-methylmorpholine-N-oxide (NMMO) solvent was heated to a complete melting at 110 ℃ and 1000g of cellulose pulp and 500g of TiO dried in a vacuum oven at 100 ℃ for 24h were added with vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂The spinning dope, which is the first spinning dope, was 30 wt.% by weight in the spinning dope.

In a similar manner, 9450g of NMMO solvent is heated to be completely melted at 110 ℃, 3750g of cellulose pulp and 300g of TiO are added under vigorous stirring and dried in a vacuum oven at 100 ℃ for 24h₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The second dope was a dope containing 30 wt.% of the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with a core layer uniformly doped with 30 wt.% of titanium dioxide particles and a skin layer uniformly doped with 7 wt.% of titanium dioxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 30 wt.% of titanium dioxide particles and the skin layer uniformly doped with 7 wt.% of titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 18

Cellulose and TiO₂Preparing a spinning solution: 8500g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated at 110 ℃ to be completely melted, 1200g of cellulose pulp and 300g of TiO dried in a vacuum oven at 100 ℃ for 24h are added under vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and TiO₂The spinning dope, which is 15 wt.% of the spinning dope, is the first spinning dope.

Similarly, 5667g of NMMO solvent was heated to 110 deg.C to completely melt, 900g of cellulose pulp and 100g of TiO dried in a vacuum oven at 100 deg.C for 24h were added with vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The second dope, which is 15 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 20 wt.% of titanium dioxide particles and the skin layer uniformly doped with 10 wt.% of titanium dioxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 20 wt.% of titanium dioxide particles and the skin layer uniformly doped with 10 wt.% of titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 19

Cellulose and Si₄N₃Preparing a spinning solution: heating 2550g of 4-methylmorpholine-N-oxide (NMMO) solvent at 110 deg.C to completely melt, adding 450g of cellulose pulp and 300g of Si dried in a vacuum oven at 100 deg.C for 24h under vigorous stirring₄N₃Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to obtain cellulose and Si₄N₃15 wt.% of the spinning dope in the spinning dope. I.e. the first dope.

Similarly, 3400g NMMO solvent is heated at 110 ℃ to be completely melted, 570g cellulose pulp and 30g TiO which are dried in a vacuum oven at 100 ℃ for 24h are added under vigorous stirring₂Particles (diameter is 400nm), placing the solution at 20 ℃ for standing and defoaming to finally obtain cellulose and TiO₂The second dope, which is 15 wt.% of the dope in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the sheath-core structure radiation refrigeration fiber with the core layer uniformly doped with 40 wt.% silicon nitride particles and the skin layer uniformly doped with 5 wt.% titanium dioxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound and separated on a cloth roller, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 40 wt.% silicon nitride particles and the skin layer uniformly doped with 5 wt.% titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 20

Cellulose and TiO₂Preparing a spinning solution: 9900g of 4-methylmorpholine-N-oxide (NMMO) solvent is heated to be completely melted at 110 ℃, 50g of cellulose pulp and 50g of TiO which is dried for 24h in a vacuum oven at 100 ℃ are added under vigorous stirring₂Particles (diameter is 5 μm), standing the solution at 20 deg.C for defoaming to obtain cellulose and TiO₂The spinning dope, which is the first spinning dope, is 1 wt.% by weight in the spinning dope.

In a similar manner, 2475g of NMMO solvent are heated to completion at 110 ℃Completely melting, adding 200g of cellulose pulp and 50g of TiO which are dried for 24h in a vacuum oven at 100 ℃ under vigorous stirring₂The particles (diameter is 5 μm), placing the solution at 20 deg.C for standing and defoaming to obtain cellulose and TiO₂The second dope was a dope of 1 wt.% in the dope.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 50 wt.% of titanium dioxide particles and the skin layer uniformly doped with 20 wt.% of titanium dioxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigeration fiber with the core layer uniformly doped with 50 wt.% of titanium dioxide particles and the skin layer uniformly doped with 20 wt.% of titanium dioxide particles is obtained, and the fabric is shown in fig. 9.

Example 21

Cellulose and TiO₂Preparing a spinning solution: 2143g of 4-methylmorpholine-N-oxide (NMMO) solvent are heated at 110 ℃ to completely melt, 4900g of cellulose pulp and 100g of NMMO are added with vigorous stirringTiO dried for 24 hours in a vacuum oven at 100 DEG C₂Particles (diameter is 10 μm), standing the solution at 20 deg.C for defoaming to obtain cellulose and TiO₂The spinning dope is 70 wt.% in the spinning dope, i.e., the first spinning dope.

Similarly, 2143g of NMMO solvent is heated at 110 ℃ to be completely melted, 4900g of cellulose pulp and 100g of ZnO particles (diameter is 10 μm) are added under vigorous stirring and dried in a vacuum oven at 100 ℃ for 24h, the solution is placed at 20 ℃ for standing and defoaming, and finally 70 wt.% of spinning solution of cellulose and ZnO in the spinning solution is obtained, namely the second spinning solution.

Preparing radiation refrigeration fiber by dry-wet spinning: and respectively transferring the first spinning solution and the second spinning solution to a first spinning medicine tank and a second spinning medicine tank through a metering pump and a candle filter, wherein the spinning temperature is 110 ℃, the spinning speed is 500m/min, the spinning solution is sprayed out through double core spray holes to pass through an air layer of 50mm and then reach a water coagulation bath at 80 ℃, and the nascent fiber is obtained after the coagulation bath stretching. Bundling, preheating bath stretching, boiling water or steam bath stretching, hot water washing, oiling, drying densification, dry heat stretching, curling and heat setting are carried out on the nascent fiber to obtain the skin-core structure radiation refrigeration fiber with the skin-core layer uniformly doped with 2 wt.% titanium dioxide particles and the skin layer uniformly doped with 2 wt.% zinc oxide particles, the cross section of the radiation refrigeration fiber is shown in figure 5, and then the obtained radiation refrigeration fiber is collected to a winding roller.

Preparation of radiation refrigerating fabric: the obtained radiation refrigeration fibers are respectively used as weft yarns and warp yarns, and in order to avoid the fibers from being worn under the action of over-strong friction, the warp yarns of the cloth roller are adjusted to ensure uniform tension and proper tightness; according to the change rule of warp and weft interweaving, an upper layer of warp and a lower layer of warp are driven in sequence by utilizing a shedding mechanism to form a shed channel; the fiber is wound on the shuttle to be used as weft yarn, the shuttle is woven through a shed channel in a reciprocating and alternating mode, the arrangement density of the weft yarn is adjusted by matching with other mechanisms on a weaving machine, and the fabric is wound on a cloth roller and is guided away, so that the fabric woven by the skin-core structure radiation refrigerating fiber with the core layer uniformly doped with 2 wt.% of titanium dioxide particles and the skin layer uniformly doped with 2 wt.% of zinc oxide particles is obtained, and the fabric is shown in fig. 9.

Comparative example 1

Comparative example 1 differs from example 1 only in that comparative example 1 was prepared by electrospinning, and the specific operating procedure was as described in example 1 of chinese patent application CN110042564A, to provide a radiation-cooled fiber.

Comparative example 2

Comparative example 2 differs from example 1 only in that comparative example 2 was prepared by a melt process, the specific operating procedures of which are described in example 1 of chinese patent application CN111455483A, to give a radiation-cooled fibre.

Comparative example 3

The comparative example 3 is different from the example 1 only in that the comparative example 3 does not contain the radiation refrigeration fiber obtained by the inorganic micro-nano particles.

TABLE 1 dosage of the various components in the examples and comparative examples

Examples of the experiments

The radiation refrigeration fabrics obtained in examples 1 to 14 and the radiation refrigeration fabrics obtained in comparative examples 1 to 3 were subjected to experiments, and the specific operation method was as follows: the reflectivity of the fabric in a solar radiation (0.3-2.5 mu m) wave band is tested by using a UV-VIS-NIR spectrophotometer in combination with an integrating sphere, and the emissivity of the fabric in a middle infrared (8-13 mu m) wave band is tested by using a Fourier transform infrared spectrometer in combination with the integrating sphere. The results obtained are shown in table 2.

Table 2 reflectivity results for radiation cooled fabrics in the solar band and average emissivity results in the mid-infrared band

As can be seen from Table 2, the average emissivity of the radiation refrigeration fabric in the 8-13 μm waveband is above 0.90, and the average reflectivity of the radiation refrigeration fabric in the sunlight waveband is above 0.90, which indicates that the fabric prepared by using the radiation refrigeration fiber of the present invention has good performance.

Comparing comparative example 1 with comparative example 2 and example 1, which are different only in the method used, comparative example 1 uses the radiation refrigerating fiber prepared by the electrospinning method, comparative example 2 uses the radiation refrigerating fiber prepared by the melting method, and the radiation refrigerating woven fabric obtained has the average emissivity in the 8-13 μm band and the average reflectivity in the solar light band as shown in table 2, and it can be seen from table 2 that the average emissivity in the 8-13 μm band of the fabric described in example 1 is not 0.92, the average reflectivity in the solar light band is not 0.92, while the average reflectivity in the 8-13 μm band of the fabric described in example 1 is 0.90 and 0.85, respectively, and the average reflectivity in the solar light band of the fabric described in example 1 is 0.91 and 0.90, respectively, which shows that the fabric woven by the radiation refrigerating fiber prepared by the method described in the present invention has a good effect.

Comparing example 3 with example 1, the difference is that comparative example 3 does not contain inorganic micro-nano particles to prepare radiation refrigeration fibers, the average emissivity of the woven fabric in a wave band of 8-13 μm and the average reflectivity of the woven fabric in a solar wave band are shown in table 2, as can be seen from table 2, the average emissivity of the woven fabric in example 1 in the wave band of 8-13 μm is not 0.92, the average reflectivity in the solar wave band is not 0.92, and comparative example 1 is 0.90 and 0.60 respectively, which shows that the fabric containing inorganic micro-nano particles has a better effect.

In conclusion, the radiation refrigeration fiber doped with the inorganic micro-nano particles is prepared by using a dry-wet spinning process, has excellent radiation refrigeration effect, and is woven into a flexible fabric suitable for cooling the surface of human skin, the average emissivity of the prepared radiation refrigeration fabric in a wave band of 8-13 microns is more than or equal to 0.9, and the average reflectivity in a solar wave band is more than or equal to 0.9.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.