Multi-layer fiber membrane capable of adjusting heat and humidity balance of human body and manufacturing method of multi-layer fiber membrane

Abstract

The invention discloses a multi-layer fiber membrane capable of adjusting heat and humidity balance of a human body and a manufacturing method thereof, and relates to the technical field of paints.A multi-layer composite membrane with hydrophobic-flow guide-super-hydrophilic multi-stage wetting gradient and one-way moisture guide performance is constructed mainly through an electrostatic spinning technology. The outer layer of the multi-layer composite membrane is formed by compounding a hydrophilic polymer and micro-nano particles, the inner layer is a hydrophobic polyurethane layer, and the middle flow guide layer is a polyurethane-hydrophilic polymer composite fiber layer. Under the action of the wetting gradient effect and the differential capillary effect of the porous micro-nano structure, when a human body sweats, sweat can be rapidly conducted to the outer layer from the inner layer of the multi-layer composite film, a good cooling effect is achieved, meanwhile, sweat is rapidly discharged, heat is prevented from being accumulated in a human-clothing microenvironment, and the heat absorption effect is good. The fabric ensures that the skin of a human body is dry and comfortable, solves the problem that the heat and humidity adjusting performance of the fabric is difficult to cooperate, and can meet the personalized heat and humidity adjusting requirements of the human body in different environments.

Description

Technical Field

[0001] The invention relates to the technical field related to textile materials, and in particular to a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body and a manufacturing method thereof. Background Art

[0002] One of the basic functions of clothing is to create a comfortable and stable microenvironment for the human body, so that the human body can move normally in different environments. Thermal and moisture comfort research is an important topic in clothing comfort research. It is based on ergonomics and regards the human body, clothing, and environment as a system to explore the balance of energy exchange between the heat generated by the human body and the heat dissipated by the human body through clothing.

[0003] In the "human-clothing-environment" system, the heat exchange between the human body and the environment is mainly in the form of radiation, conduction, convection and evaporation. When the skin temperature is 32±1℃, people usually feel comfortable, and in the indoor environment, they mainly dissipate heat by radiation, conduction and convection. Clothing plays a role in both heat conduction and heat insulation between humans and the environment.

[0004] In recent years, people's demand for comfort and increased awareness of environmental protection have promoted the development of radiative cooling textiles. Radiative cooling textiles use fiber materials with radiative cooling capabilities to spontaneously reflect sunlight (wavelength range of 0.3-2.5 μm) and human infrared radiation (main wavelength range of 7-14 μm) selectively into the external environment, achieving personal cooling without consuming energy. Chinese patent publication number CN115323801A discloses a coated textile with all-day efficient passive radiative cooling function and a preparation method thereof. The coated textile adds inorganic particles and sets a porous structure in the radiative cooling layer, making full use of its scattering effect on sunlight, effectively increasing the reflectivity of sunlight, thereby improving the radiative cooling effect, and at the same time, giving the coated textile good self-cleaning properties. Chinese patent publication number CN114457509A discloses an ultra-thin radiation cooling fiber membrane based on a micro-nano multi-level structure and a preparation method thereof. The invention adds polymers and nanoparticles into a mixed solvent, and prepares an ultra-thin radiation cooling fiber membrane based on a micro-nano multi-level structure by electrospinning after ultrasonic dispersion. In view of the problem of insufficient weighted average reflectivity of sunlight when the material thickness is low, a micro-nano multi-level structure with super scattering efficiency is designed to enhance the ability of low-thickness materials to reflect sunlight.

[0005] However, the above inventions mainly focus on how to improve the spectral selectivity of the materials in the development of textile materials, ignoring the importance of efficient heat dissipation methods such as sweat transfer and evaporation in outdoor personal thermal and humidity comfort regulation. When a person is in a hot and humid environment and exercises vigorously or absorbs too much external heat, the skin surface temperature may exceed 35°C, and the main heat dissipation pathway will be sweat evaporation. Once the synergistic effect of the heat dissipation pathways is insufficient to dissipate the heat accumulated in the human body, the core body temperature of the human body will continue to rise and stimulate the production of a large amount of sweat, resulting in dehydration caused by excessive sweat evaporation or heat stress-related diseases. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a multi-layer fiber membrane that can regulate the thermal and moisture balance of the human body and a method for manufacturing the same, aiming to solve the above-mentioned technical problems. The present invention mainly uses electrospinning technology to construct a multi-layer composite membrane with a multi-level wetting gradient of hydrophobic-conductive-super hydrophilic and a unidirectional moisture-conducting performance, so that sweat can be quickly conducted from the inner layer to the outer layer of the multi-layer composite membrane, achieving a good cooling effect. At the same time, it can quickly perspire and prevent heat from accumulating in the "human-clothing" microenvironment, ensuring that human skin is dry and comfortable, solving the problem of the difficulty in coordinating the thermal and moisture regulation performance of fabrics, and meeting the personalized thermal and moisture regulation needs of the human body in different environments.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] A method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body comprises the following steps:

[0009] (1) Preparation of waterborne polyurethane emulsion: In parts by weight, waterborne polyurethane emulsion is prepared according to the following proportions: 20-30 parts of dehydrated polyester or polyether diol are added to a reaction bottle, and then 10-15 parts of diisocyanate and 0.01-0.1 parts of organic tin catalyst are added in sequence, the temperature is raised to 65-95° C., and after reacting for 2 hours, 1-3 parts of small molecule chain extender are added, and after continuing to react at 50-80° C. for 1-2 hours, 3-5 parts of post-chain extender and neutralizer are added, and after reacting at 45-60° C. for 2 hours, 90-120 parts of deionized water are added under high-speed stirring for emulsification, and stirring is continued for 1-2 hours to obtain waterborne polyurethane emulsion, which is sealed for later use;

[0010] (2) Preparation of hydrophilic layer spinning solution: Prepare a hydrophilic layer spinning solution of nanoparticles in the following proportions by weight: mix 5-10 parts of nanoparticles, 15-30 parts of hydrophilic polymer, and 100 parts of solvent, and ultrasonicate for 5-10 minutes to promote uniform dispersion, thereby obtaining a hydrophilic layer spinning solution of nanoparticles for later use;

[0011] (3) Preparation of guide layer spinning solution: Prepare the guide layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 0.1-1.2 parts of the hydrophilic polymer, 10-30 parts of the solvent, and 0.5-1.3 parts of the spinning aid are mixed evenly to obtain the guide layer spinning solution for later use;

[0012] (4) Preparation of hydrophobic layer spinning solution: Prepare a hydrophobic layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 8 to 15 parts of deionized water, and 0.3 to 1.5 parts of a spinning aid, mix them uniformly at room temperature to obtain a hydrophobic layer spinning solution for later use;

[0013] (5) Preparation of a multilayer composite membrane capable of regulating heat and moisture balance of the human body: adding the hydrophilic layer spinning solution prepared in step (2) into a syringe, and depositing a layer of hydrophilic nanofiber membrane on the receiving substrate by an electrospinning method, and controlling its thickness to be 70-90 μm; taking 10 parts of the guide layer spinning solution prepared in step (3), adding 0.3-1.5 parts of a cross-linking agent, stirring for 2-3 minutes, and adding the solution into a syringe, and depositing at least one layer of guide layer fiber membrane on the hydrophilic layer by an electrospinning method, and controlling its thickness to be 30-50 μm; taking 10 parts of the hydrophobic layer spinning solution prepared in step (4), adding 0.3-1.5 parts of a cross-linking agent, stirring for 2-3 minutes, and adding the solution into a syringe, and depositing at least one layer of hydrophobic nanofiber membrane on the guide layer by an electrospinning method, and controlling its thickness to be 10-30 μm, thereby obtaining a multilayer fiber membrane having unidirectional moisture conduction and radiant cooling functions.

[0014] Preferably, the polyester or polyether diol in step (1) is any one or more combinations of YmerN120 which is a white solid at room temperature, polybutylene glycol, polypropylene glycol, polyethylene glycol, polyethylene carbonate diol and polypropylene carbonate diol with a relative molecular mass of 1000 to 2000.

[0015] Preferably, the post-chain extender and neutralizer in step (1) are any one or more combinations of gallic acid, ethylenediamine, hydrazine hydrate, isophoronediamine, diethylenetriamine, and tris(hydroxymethyl)aminomethane.

[0016] Preferably, the nanoparticles in step (2) are one or more combinations of aluminum nitride, silicon nitride, silicon dioxide, zinc oxide, aluminum oxide, silicon carbide, aluminum phosphate, barium sulfate and titanium dioxide.

[0017] Preferably, the hydrophilic polymer in step (2) is one or more of cellulose acetate, polyacrylonitrile, polyethylene oxide, polyamide and polyimide.

[0018] Preferably, the solvent of step (2) and step (3) is one or more combinations of water, acetic acid, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, isopropanol, tetrahydrofuran, formic acid, ethylene glycol, glycerol, and ethyl acetate.

[0019] Preferably, the spinning aid in step (2) and step (3) is one or more combinations of polyethylene oxide and polyvinyl alcohol.

[0020] Preferably, the cross-linking agent in step (5) is one or more combinations of hexamethylene diisocyanate trimer, hydrophilic polyisocyanate and aziridine.

[0021] Preferably, the electrospinning voltage is 15-30 kV, the relative humidity is 30-60%, the injection speed is 0.5-2 mL / h, and the receiving distance is 15-30 cm.

[0022] A multilayer fiber membrane capable of regulating heat and moisture balance of a human body, prepared by any of the preparation methods described above.

[0023] The multilayer fiber membrane capable of adjusting the heat and moisture balance of the human body and the manufacturing method thereof of the present invention have the following beneficial effects:

[0024] 1. The multilayer fiber membrane capable of regulating the heat and moisture balance of the human body is prepared by an electrospinning process, and comprises a hydrophilic layer, a guide layer and a hydrophobic layer, wherein the hydrophilic layer can effectively regulate the hydrophilicity and hydrophobicity and the fine structure of the fiber by doping with a hydrophilic polymer and a micro-nano material, thereby creating a material with super-hydrophilic properties; the guide layer is composed of hydrophilic and hydrophobic nanofibers, and the ratio of the two is adjusted to achieve excellent guide and anti-reverse osmosis effects, thereby ensuring that the hydrophobic surface remains dry; this structural design can simultaneously achieve unidirectional water conduction, moisture conduction and quick-drying properties, and when the human body sweats, the sweat can be quickly transferred out from the inside of the clothing to ensure that the human skin is dry;

[0025] 2. The multilayer fiber membrane of the present invention can adjust the heat and moisture balance of the human body. The porous micro-nano structure and the introduced micro-nano particles can improve the reflectivity of sunlight and reduce the heat intake, thereby improving the radiation cooling effect. The micro-nano particles have a high emissivity in the 8-13μm atmospheric window, so that the heat is radiated to the outer space, further improving the radiation cooling effect;

[0026] 3. Compared with traditional fabrics, the multilayer fiber membrane of the present invention can regulate the thermal and moisture balance of the human body. By utilizing the advantages of unidirectional liquid conduction and micro-nano fiber refinement in the field of thermal and moisture regulation, on the one hand, it realizes rapid unidirectional moisture conduction through the wetting gradient effect and the differential capillary effect, and on the other hand, it realizes passive cooling through the spectral characteristics of the material and the porous structure, thereby realizing efficient heat and moisture transfer of the human body during outdoor activities, preventing heat accumulation in the "human-clothing" microenvironment, solving the problem of the difficulty in coordinating the thermal and moisture regulation performance of fabrics, and meeting the personalized thermal and moisture regulation needs of the human body in different environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the emissivity of the multilayer fiber membrane of Examples 1-3 of the present invention;

[0028] Figure 2 Schematic diagram of reflectivity of multilayer fiber membranes of Examples 1-3 of the present invention;

[0029] Figure 3 Schematic diagram of the temperature difference that can be achieved by the multilayer fiber membrane of embodiments 1-3 of the present invention relative to ordinary cotton cloth in an outdoor environment;

[0030] Figure 4 Schematic diagram of the temperature difference that can be achieved by the multilayer fiber membrane of Examples 1-3 of the present invention relative to ordinary cotton cloth in a test simulating the outdoor cooling performance of the human body. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention, the product of the present invention is further described in detail below in conjunction with embodiments and drawings.

[0032] It should be noted that all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] Example 1

[0034] A method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body comprises the following steps:

[0035] (1) Preparation of aqueous polyurethane emulsion: In parts by weight, an aqueous polyurethane emulsion was prepared according to the following proportions: 15 parts of dehydrated linear polyethylene glycol difunctional methyl ether and 8 parts of polybutylene glycol were added to a reaction bottle, and then 12 parts of diisocyanate and 0.01 parts of an organic tin catalyst were added in sequence. The temperature was raised to 80° C., and after reacting for 2 hours, 2 parts of 1,4-butanediol were added. After continuing to react at 60° C. for 2 hours, 4 parts of gallic acid were added. After reacting at 55° C. for 2 hours, 96 parts of deionized water were added under high-speed stirring for emulsification, and stirring was continued for 2 hours to obtain an aqueous polyurethane emulsion, which was sealed for later use.

[0036] (2) Preparation of hydrophilic layer spinning solution: Nanoparticle-hydrophilic layer spinning solution was prepared in the following proportions by weight: 7.5 parts of aluminum oxide nanoparticles, 22 parts of cellulose acetate, 75 parts of acetic acid, and 25 parts of water were mixed, and ultrasonicated for 10 minutes to promote uniform dispersion, to obtain a hydrophilic layer spinning solution for later use;

[0037] (3) Preparation of guide layer spinning solution: Prepare the guide layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 0.15 parts of cellulose acetate, 13 parts of acetic acid, and 1 part of polyethylene oxide are mixed evenly to obtain a guide layer spinning solution for later use;

[0038] (4) Preparation of hydrophobic layer spinning solution: Prepare a hydrophobic layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 12 parts of deionized water, and 1 part of polyethylene oxide, mix them uniformly at room temperature to obtain a hydrophobic layer spinning solution for later use;

[0039] (5) Preparation of a multilayer composite membrane with unidirectional moisture conduction and radiation cooling functions: The hydrophilic layer spinning solution prepared in step (2) was added into a syringe, and a layer of hydrophilic nanofiber membrane was deposited on a receiving substrate by an electrospinning method. The relative humidity was 45%, the spinning voltage was 20 kV, the receiving distance was 21 cm, the perfusion rate of the spinning solution was 1 mL / h, and the thickness of the fiber membrane was controlled to be 80 μm; 10 parts of the guide layer spinning solution prepared in step (3) were taken, 0.6 parts of a cross-linking agent was added, and after stirring for 2 minutes, the solution was added into a syringe, and a layer of guide layer fiber was deposited on the hydrophilic layer by an electrospinning method. The invention discloses a multi-layer fiber membrane having a relative humidity of 45%, a spinning voltage of 25 kV, a receiving distance of 21 cm, an injection speed of 1 mL / h, and a thickness of the hydrophilic layer of 40 μm; 10 parts of the hydrophobic layer spinning solution prepared in step (4) are added with 0.6 parts of a cross-linking agent, stirred for 2 minutes, and then added into a syringe, and a layer of hydrophobic nanofiber membrane is deposited on the guide layer by an electrospinning method, and the relative humidity is 45%, the spinning voltage is 25 kV, the receiving distance is 21 cm, and the injection speed is 1 mL / h, and the thickness is controlled at 20 μm, thereby obtaining a multi-layer fiber membrane having unidirectional moisture conduction and radiation cooling functions.

[0040] Example 2

[0041] A method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body comprises the following steps:

[0042] (1) Preparation of waterborne polyurethane emulsion: In parts by weight, waterborne polyurethane emulsion was prepared according to the following proportions: 15 parts of dehydrated linear polyethylene glycol difunctional methyl ether and 8 parts of polybutylene glycol were added to a reaction bottle, and then 12 parts of diisocyanate and 0.01 parts of an organic tin catalyst were added in sequence. The temperature was raised to 80° C., and after reacting for 2 hours, 2 parts of 1,4-butanediol were added. After continuing to react at 60° C. for 2 hours, 3 parts of tris(hydroxymethyl)aminomethane were added. After reacting at 55° C. for 2 hours, 96 parts of deionized water were added under high-speed stirring for emulsification, and stirring was continued for 2 hours to obtain waterborne polyurethane emulsion, which was sealed for later use.

[0043] (2) Preparation of hydrophilic layer spinning solution: Nanoparticle-hydrophilic layer spinning solution was prepared in the following proportions by weight: 7.5 parts of aluminum nitride nanoparticles, 22 parts of polyacrylonitrile, 75 parts of acetic acid, and 25 parts of water were mixed, and ultrasonicated for 10 minutes to promote uniform dispersion to obtain a hydrophilic layer spinning solution for later use;

[0044] (3) Preparation of guide layer spinning solution: Prepare the guide layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 0.3 parts of polyacrylonitrile, 13 parts of acetic acid, and 1 part of polyethylene oxide are mixed evenly to obtain the guide layer spinning solution for later use;

[0045] (4) Preparation of hydrophobic layer spinning solution: Prepare a hydrophobic layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 12 parts of deionized water, and 1 part of polyethylene oxide, mix them uniformly at room temperature to obtain a hydrophobic layer spinning solution for later use;

[0046] (5) Preparation of a multilayer composite membrane with unidirectional moisture conduction and radiation cooling functions: The hydrophilic layer spinning solution prepared in step (2) was added into a syringe, and a layer of hydrophilic nanofiber membrane was deposited on a receiving substrate by an electrostatic spinning method. The relative humidity was 50%, the spinning voltage was 20 kV, the receiving distance was 21 cm, the perfusion rate of the spinning solution was 1 mL / h, and the thickness of the fiber membrane was controlled to be 80 μm; 10 parts of the guide layer spinning solution prepared in step (3) were taken, 0.6 parts of a cross-linking agent was added, and after stirring for 2 minutes, the solution was added into a syringe, and a layer of guide layer fiber was deposited on the hydrophilic layer by an electrostatic spinning method. The invention discloses a multi-layer fiber membrane having a relative humidity of 50%, a spinning voltage of 25 kV, a receiving distance of 21 cm, an injection speed of 1 mL / h, and a thickness of the hydrophilic layer of 40 μm; 10 parts of the hydrophobic layer spinning solution prepared in step (4) are added with 0.6 parts of a cross-linking agent, stirred for 2 minutes, and then added into a syringe, and a layer of hydrophobic nanofiber membrane is deposited on the guide layer by an electrospinning method, and the relative humidity is 50%, the spinning voltage is 25 kV, the receiving distance is 21 cm, and the injection speed is 1 mL / h, and the thickness is controlled at 20 μm, thereby obtaining a multi-layer fiber membrane having unidirectional moisture conduction and radiation cooling functions.

[0047] Example 3

[0048] A method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body comprises the following steps:

[0049] (1) Preparation of waterborne polyurethane emulsion: In parts by weight, waterborne polyurethane emulsion was prepared according to the following proportions: 15 parts of dehydrated linear polyethylene glycol difunctional methyl ether and 8 parts of polypropylene glycol were added to a reaction bottle, and then 12 parts of diisocyanate and 0.01 parts of an organic tin catalyst were added in sequence. The temperature was raised to 80° C., and after reacting for 2 hours, 2 parts of 1,4-butanediol were added. After continuing to react at 60° C. for 2 hours, 4 parts of ethylenediamine were added. After reacting at 55° C. for 2 hours, 96 parts of deionized water were added under high-speed stirring for emulsification, and stirring was continued for 2 hours to obtain a waterborne polyurethane emulsion, which was sealed for later use.

[0050] (2) Preparation of hydrophilic layer spinning solution: Nanoparticle-hydrophilic layer spinning solution was prepared in the following proportions by weight: 7.5 parts of silica nanoparticles, 22 parts of cellulose acetate, 75 parts of acetic acid, and 25 parts of water were mixed, and ultrasonicated for 10 minutes to promote uniform dispersion, to obtain hydrophilic layer spinning solution, which was set aside;

[0051] (3) Preparation of guide layer spinning solution: Prepare the guide layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 0.5 parts of cellulose acetate, 13 parts of acetic acid, and 1 part of polyethylene oxide are mixed evenly to obtain a guide layer spinning solution for later use;

[0052] (4) Preparation of hydrophobic layer spinning solution: Prepare a hydrophobic layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 12 parts of deionized water, and 1 part of polyethylene oxide, mix them uniformly at room temperature to obtain a hydrophobic layer spinning solution for later use;

[0053] (5) Preparation of a multilayer composite membrane with unidirectional moisture conduction and radiation cooling functions: The hydrophilic layer spinning solution prepared in step (2) was added into a syringe, and a layer of hydrophilic nanofiber membrane was deposited on a receiving substrate by an electrostatic spinning method. The relative humidity was 50%, the spinning voltage was 20 kV, the receiving distance was 21 cm, the perfusion rate of the spinning solution was 1 mL / h, and the thickness of the fiber membrane was controlled to be 80 μm; 10 parts of the guide layer spinning solution prepared in step (3) were taken, 0.6 parts of a cross-linking agent was added, and after stirring for 2 minutes, the solution was added into a syringe, and a layer of guide layer fiber was deposited on the hydrophilic layer by an electrostatic spinning method. The invention discloses a multi-layer fiber membrane having a relative humidity of 50%, a spinning voltage of 25 kV, a receiving distance of 21 cm, an injection speed of 1 mL / h, and a thickness of the hydrophilic layer of 40 μm; 10 parts of the hydrophobic layer spinning solution prepared in step (4) are added with 0.6 parts of a cross-linking agent, stirred for 2 minutes, and then added into a syringe, and a layer of hydrophobic nanofiber membrane is deposited on the guide layer by an electrospinning method, and the relative humidity is 50%, the spinning voltage is 25 kV, the receiving distance is 21 cm, and the injection speed is 1 mL / h, and the thickness is controlled at 20 μm, thereby obtaining a multi-layer fiber membrane having unidirectional moisture conduction and radiation cooling functions.

[0054] The multilayer fiber membrane capable of adjusting the heat and moisture balance of the human body prepared in the above embodiment was tested according to the industry standard. The test results are shown in the following table. The test method is:

[0055] Under room temperature conditions, the emissivity of the multilayer fiber membrane capable of regulating the heat and moisture balance of the human body in the 8-13μm atmospheric window was tested, and the reflectivity of the multilayer fiber membrane capable of regulating the heat and moisture balance of the human body in the 2-2.5μm band was tested; in an outdoor environment, the multilayer fiber membrane capable of regulating the heat and moisture balance of the human body obtained in the above embodiment was tested with ordinary cotton cloth, and in addition, in an outdoor environment, the multilayer fiber membrane capable of regulating the heat and moisture balance of the human body obtained in the above embodiment was tested with ordinary cotton cloth for simulated human outdoor cooling performance. Under different environments, 15 samples of the multilayer fiber membrane obtained in each embodiment and ordinary cotton cloth were selected for cooling performance testing at the same time, and the average value of the 15 cooling data obtained from the test was taken as the test result of the sample.

[0056]

[0057] like Figures 1 to 4As shown, it can be seen from the above results that the multilayer fiber membrane with unidirectional liquid guide and radiation cooling functions prepared by the preparation method of Example 1 has an emissivity of up to 96.7% in the 8-13μm atmospheric window and a reflectivity of 92.2% in the 2-2.5μm band; in outdoor environments, the multilayer fiber membrane can achieve a cooling of 12°C compared with ordinary cotton cloth; in addition, in the test of simulating human outdoor cooling performance, due to its excellent unidirectional liquid transmission ability, the multilayer fiber membrane can achieve a cooling of 15.6°C compared with ordinary cotton cloth.

[0058] The multilayer fiber membrane with unidirectional liquid guide and radiation cooling functions prepared by the preparation method of Example 2 has an emissivity of up to 96.3% in the 8-13μm atmospheric window and a reflectivity of 87.7% in the 2-2.5μm band; in outdoor environments, the multilayer fiber membrane can achieve a cooling of 11°C compared with ordinary cotton cloth; in addition, in a test simulating outdoor cooling performance of the human body, due to its excellent unidirectional liquid transmission ability, the multilayer fiber membrane can achieve a cooling of 14.5°C compared with ordinary cotton cloth.

[0059] The multilayer fiber membrane with unidirectional liquid guide and radiation cooling functions prepared by the preparation method of Example 3 has an emissivity of up to 96.1% in the 8-13μm atmospheric window and a reflectivity of 87.5% in the 2-2.5μm band; in outdoor environments, the multilayer fiber membrane can achieve a cooling of 10°C compared with ordinary cotton cloth; in addition, in a test simulating outdoor cooling performance of the human body, due to its excellent unidirectional liquid transmission ability, the multilayer fiber membrane can achieve a cooling of 14°C compared with ordinary cotton cloth.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention still belong to the present invention.

Claims

1. A method for preparing a multilayer fiber membrane capable of regulating heat and moisture balance of a human body, characterized in that: The steps include: (1) Preparation of waterborne polyurethane emulsion: In parts by weight, waterborne polyurethane emulsion is prepared according to the following proportions: 20-30 parts of dehydrated polyester or polyether diol are added to a reaction bottle, and then 10-15 parts of diisocyanate and 0.01-0.1 parts of organic tin catalyst are added in sequence, the temperature is raised to 65-95° C., and after reacting for 2 hours, 1-3 parts of small molecule chain extender are added, and after continuing to react at 50-80° C. for 1-2 hours, 3-5 parts of post-chain extender and neutralizer are added, and after reacting at 45-60° C. for 2 hours, 90-120 parts of deionized water are added under high-speed stirring for emulsification, and stirring is continued for 1-2 hours to obtain waterborne polyurethane emulsion, which is sealed for later use; (2) Preparation of hydrophilic layer spinning solution: Prepare a hydrophilic layer spinning solution of nanoparticles in the following proportions by weight: mix 5-10 parts of nanoparticles, 15-30 parts of hydrophilic polymer, and 100 parts of solvent, and ultrasonicate for 5-10 minutes to promote uniform dispersion, thereby obtaining a hydrophilic layer spinning solution of nanoparticles for later use; (3) Preparation of guide layer spinning solution: Prepare the guide layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 0.1-1.2 parts of the hydrophilic polymer, 10-30 parts of the solvent, and 0.5-1.3 parts of the spinning aid are mixed evenly to obtain the guide layer spinning solution for later use; (4) Preparation of hydrophobic layer spinning solution: Prepare a hydrophobic layer spinning solution in the following proportions by weight: 10 parts of the aqueous polyurethane emulsion prepared in step (1), 8 to 15 parts of deionized water, and 0.3 to 1.5 parts of a spinning aid, mix them uniformly at room temperature to obtain a hydrophobic layer spinning solution for later use; (5) Preparation of a multilayer composite membrane capable of regulating heat and moisture balance of the human body: adding the hydrophilic layer spinning solution prepared in step (2) into a syringe, and depositing a layer of hydrophilic nanofiber membrane on the receiving substrate by an electrospinning method, and controlling its thickness to be 70-90 μm; taking 10 parts of the guide layer spinning solution prepared in step (3), adding 0.3-1.5 parts of a cross-linking agent, stirring for 2-3 minutes, and adding the solution into a syringe, and depositing at least one layer of guide layer fiber membrane on the hydrophilic layer by an electrospinning method, and controlling its thickness to be 30-50 μm; taking 10 parts of the hydrophobic layer spinning solution prepared in step (4), adding 0.3-1.5 parts of a cross-linking agent, stirring for 2-3 minutes, and adding the solution into a syringe, and depositing at least one layer of hydrophobic nanofiber membrane on the guide layer by an electrospinning method, and controlling its thickness to be 10-30 μm, thereby obtaining a multilayer fiber membrane having unidirectional moisture conduction and radiant cooling functions.

2. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The polyester or polyether diol in step (1) is any one or more combinations of YmerN120 which is a white solid at room temperature, polybutylene glycol, polypropylene glycol, polyethylene glycol, polyethylene carbonate diol and polypropylene carbonate diol with a relative molecular mass of 1000-2000.

3. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The post-chain extender and neutralizer in step (1) are any one or more combinations of gallic acid, ethylenediamine, hydrazine hydrate, isophoronediamine, diethylenetriamine, and tris(hydroxymethyl)aminomethane.

4. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The nanoparticles in step (2) are one or more of aluminum nitride, silicon nitride, silicon dioxide, zinc oxide, aluminum oxide, silicon carbide, aluminum phosphate, barium sulfate and titanium dioxide.

5. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The hydrophilic polymer in step (2) is one or more of cellulose acetate, polyacrylonitrile, polyethylene oxide, polyamide and polyimide.

6. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The solvents of step (2) and step (3) are one or more combinations of water, acetic acid, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, isopropanol, tetrahydrofuran, formic acid, ethylene glycol, glycerol, and ethyl acetate.

7. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The spinning aid in step (2) and step (3) is one or more combinations of polyethylene oxide and polyvinyl alcohol.

8. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The cross-linking agent in step (5) is one or more combinations of hexamethylene diisocyanate trimer, hydrophilic polyisocyanate and aziridine.

9. The method for preparing a multilayer fiber membrane capable of adjusting heat and moisture balance of a human body according to claim 1, characterized in that: The electrospinning voltage is 15-30 kV, the relative humidity is 30-60%, the injection speed is 0.5-2 mL / h, and the receiving distance is 15-30 cm.

10. A multilayer fiber membrane capable of regulating heat and moisture balance of human body, characterized in that: A multilayer fiber membrane capable of regulating heat and moisture balance of the human body prepared by the preparation method according to any one of claims 1 to 9.

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