Passive radiation heating fabric and its preparation method and application

Abstract

The present invention discloses a passive radiation heating fabric, its preparation method, and its application. This relates to the technical field of heating fabrics. The passive radiation heating material comprises a stacked thermal radiation absorbing layer and an infrared radiation reflecting layer; the thermal radiation absorbing layer comprises a fiber material, hydrophobic graphene supported on the fiber material, and silica coated with the hydrophobic graphene. In the passive radiation heating material of the present invention, the graphene in the thermal radiation absorbing layer is coated with silica, forming a hydrophobic layer to protect the graphene, prevent it from falling off, and improve the fastness of the graphene on the fabric surface.

Description

Technical Field

[0001] The present invention relates to the technical field of heating fabrics, and in particular to a passive radiation heating fabric and a preparation method and application thereof. Background Art

[0002] In outdoor environments, people typically heat themselves by increasing the thickness of their clothing. Traditional clothing creates air gaps around the body, preventing heat loss through convection and conduction. This heating effect can be further enhanced by using materials with lower thermal conductivity, such as down jackets and jackets. Down jackets, typically made of a thick layer of fluffy down and feathers, act as a perfect insulating layer to reduce conductive heat loss. Jackets, by their windproofing effect, reduce air convection between the inside and outside of the garment, thus preventing significant heat loss from the body. Generally speaking, there are four main ways that heat is lost from the human body: convection, conduction, evaporation, and radiation. Radiation accounts for over 50% of heat loss. This shows that considering only convection and conduction as factors for heat loss is insufficient. To achieve thermal comfort tailored to the human microenvironment, research on heating by suppressing radiative heat dissipation has garnered significant attention.

[0003] Passive radiant heating materials utilize thermal management materials to prevent the loss of radiant heat from the human body, thereby utilizing the body's own unused radiant heat for warmth. Traditional mass-market apparel, such as down jackets and jackets, does not process human radiation because the materials (fabrics) they are made of typically have high emissivity (0.75–0.9), which results in radiant heat loss. Passive radiant heating fabrics absorb solar heat while simultaneously blocking as much radiant heat loss from the body as possible, maximizing heat input and minimizing heat output.

[0004] However, existing passive radiant heating materials are ineffective. Current methods for preparing passive radiant heating materials rely on an immersion process: a graphene solution is prepared, fabric is immersed in it, and then a hydrophobic solution is prepared. This process also results in a hydrophobic graphene fabric. This process can easily cause a small amount of graphene to fall off during the second step. Therefore, there is an urgent need for a new passive radiant heating material that can minimize the loss of radiant heat from the human body. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is:

[0006] A passive radiant heating material is provided.

[0007] The second technical problem to be solved by the present invention is:

[0008] Provided is a method for preparing the passive radiation heating material.

[0009] The third technical problem to be solved by the present invention is:

[0010] Application of the passive radiation heating material.

[0011] In order to solve the first technical problem, the technical solution adopted by the present invention is:

[0012] A passive radiation heating material, comprising a thermal radiation absorbing layer and an infrared radiation reflecting layer stacked together;

[0013] The components of the thermal radiation absorbing layer include:

[0014] Fiber material, hydrophobic graphene supported on the fiber material, and silicon dioxide covering the hydrophobic graphene.

[0015] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0016] The passive radiation heating material of the present invention contains silicon dioxide and hydrophobic graphene in the thermal radiation absorbing layer, so that the thermal radiation absorbing layer has the effect of enhancing the absorption of solar radiation heat and waterproofing, while the infrared radiation reflecting layer can serve as the inner layer of the fabric to enhance the heating performance of the passive radiation heating material by suppressing the emission of human body radiation.

[0017] In the passive radiation heating material of the present invention, the graphene in the heat radiation absorbing layer is wrapped by a hybrid of silicon dioxide and hexadecyltrimethoxysilane to form a hydrophobic layer to protect the graphene, prevent the graphene from falling off, and improve the fastness of the graphene on the fabric surface.

[0018] Compared with ordinary polyester materials, the passive radiation heating material of the present invention has better thermal insulation performance; after 50 wash cycle tests, the passive radiation heating material of the present invention still has excellent light and thermal performance, indicating that the passive radiation heating material of the present invention has good thermal management capabilities and durability, which shows that the passive radiation heating material of the present invention is extremely valuable.

[0019] According to one embodiment of the present invention, the infrared radiation reflecting layer includes at least one layer selected from the group consisting of an aluminum layer, a silver layer, and a titanium layer.

[0020] According to one embodiment of the present invention, the raw materials of the hydrophobic graphene include the following components: graphene, tetraethyl orthosilicate and hexadecyltrimethoxysilane.

[0021] According to one embodiment of the present invention, the fiber material includes at least one of polyester, cotton and linen.

[0022] According to one embodiment of the present invention, the fiber material may be any fiber material suitable for making clothing.

[0023] According to one embodiment of the present invention, the reflectivity of the passive radiation heating material in the radiation wavelength range of 7-14 μm is greater than 90%.

[0024] In order to solve the second technical problem, the technical solution adopted by the present invention is:

[0025] A method for preparing the passive radiation heating material comprises the following steps:

[0026] S1: mixing fiber material, tetraethyl orthosilicate and hexadecyltrimethoxysilane in a graphene solution, adding an ammonia solution, and reacting to obtain a modified fiber material;

[0027] S2: providing an infrared radiation reflecting layer on the surface of the modified fiber material to obtain the passive radiation heating material.

[0028] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0029] The method for preparing the passive radiation heating material of the present invention uses a bubble stirring method to prepare a graphene thermal radiation absorption layer with a hydrophobic function, thereby overcoming the disadvantage that the immersion method in the prior art may cause the graphene to fall off. The method of the present invention uses ammonia catalysis to initiate a hydrolysis and condensation reaction of tetraethyl orthosilicate and hexadecyltrimethoxysilane to produce a hybrid of silicon dioxide and hexadecyltrimethoxysilane, thereby forming a hydrophobic layer to protect the graphene, improve the fastness of the graphene on the fabric surface, and avoid the shedding of the graphene; in addition, the method of the present invention can prepare the modified fiber material in just one step, making the preparation of the material more efficient and convenient.

[0030] According to one embodiment of the present invention, the volume concentration ratio of tetraethyl orthosilicate to hexadecyltrimethoxysilane is 4-8:5-10.

[0031] According to one embodiment of the present invention, the fiber material has a length of 10-20 cm and a width of 10-20 cm.

[0032] According to one embodiment of the present invention, the concentration of the graphene solution is 1.0-2.0 mg / mL.

[0033] According to one embodiment of the present invention, the concentration of the graphene solution is selected from any one of the following concentrations or a concentration range consisting of any two of the following concentrations: 1.1 mg / mL, 1.2 mg / mL, 1.3 mg / mL, 1.4 mg / mL, 1.5 mg / mL, 1.6 mg / mL, 1.7 mg / mL, 1.8 mg / mL, 1.9 mg / mL, and 2.0 mg / mL.

[0034] According to one embodiment of the present invention, the volume percentage of the ammonia solution is 10-20 v / v%.

[0035] According to one embodiment of the present invention, the volume percentage of the ammonia solution is selected from any one of the following volume percentages or the interval consisting of any two volume percentages: 10v / v%, 11v / v%, 12v / v%, 13v / v%, 14v / v%, 15v / v%, 16v / v%, 17v / v%, 18v / v%, 19v / v%, 20v / v%.

[0036] According to one embodiment of the present invention, step S1 further includes the following steps: adding aqueous ammonia solution dropwise within 1-2 hours until the reaction is complete.

[0037] According to one embodiment of the present invention, step S1 further includes the following steps: drying the modified fiber material obtained in S1 in air and baking it in a vacuum oven at a temperature of 130-230° C. for 1-2 hours.

[0038] According to one embodiment of the present invention, the baking temperature is selected from any one of the following temperatures or an interval consisting of any two temperatures: 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, and 230°C.

[0039] According to one embodiment of the present invention, in step S2, an infrared radiation reflecting layer is provided on the surface of the modified fiber material by magnetron sputtering.

[0040] According to one embodiment of the present invention, when the magnetron sputtering method is used, its parameters are set as shown in Table 1:

[0041] Table 1

[0042]

[0043]

[0044] Another aspect of the present invention relates to the use of the passive radiant heating material in a fabric having passive radiant heating capabilities. This includes the passive radiant heating material described in the embodiment of the first aspect. Because this application utilizes all of the technical solutions of the passive radiant heating material described above, it at least has all the beneficial effects of the technical solutions of the aforementioned embodiment.

[0045] The present invention also includes a fabric comprising the passive radiation heating material.

[0046] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0048] Figure 1 This is a flow chart of step S1 in Example 1.

[0049] Figure 2 This is a flow chart of step S2 in Example 1.

[0050] Figure 3 This is a working schematic diagram of the passive radiation heating material obtained in Example 1.

[0051] Figure 4 This is the absorbance test chart of the passive radiation heating material obtained in Examples 1-5.

[0052] Figure 5 This is a scanning electron microscope image of the passive radiation heating material obtained in Example 1.

[0053] Figure 6 The passive radiation heating material obtained in Example 1 was subjected to X-ray photoelectron spectroscopy.

[0054] Figure 7 This is the absorbance test chart of the passive radiation heating material obtained in Example 1.

[0055] Figure 8 This is a test chart of the infrared reflectivity of the passive radiation heating material obtained in Example 1.

[0056] Figure 9 This is a test diagram of the thermal performance of the passive radiation heating material obtained in Example 1 under light conditions.

[0057] Figure 10 Schematic diagram of the heating performance principle of the passive radiation heating material obtained in Example 1.

[0058] Figure 11 This is a test chart of the thermal management performance of the passive radiation heating material obtained in Example 1 in terms of washability. DETAILED DESCRIPTION

[0059] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0060] The terms "preferably," "more preferably," and the like, used herein refer to embodiments of the present invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the present invention.

[0061] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges subsumed therein.

[0062] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of the present invention.

[0063] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0064] In the examples, hexadecyltrimethoxysilane (HDTMS) was provided by Nanjing UP Chemical Co., Ltd. (China). Tetraethyl orthosilicate (TEOS) and ammonia were purchased from Xilong Science Co., Ltd. (China). Graphene ethanol solution (1.0 g / mL) was purchased from Suzhou Carbon Graphene Technology Co., Ltd. Anhydrous alcohol was obtained from Guangdong Guanghua Technology Co., Ltd. (China). All chemicals were of analytical reagent grade and used as received without further purification. Deionized water was used in all experiments. Artificial sweat was purchased from Guangzhou Pengchen Biotechnology Co., Ltd. Commercially available woven polyester fabric was purchased from the local market.

[0065] In the embodiment, the models of the instruments used are shown in Table 2 below:

[0066] Table 2

[0067]

[0068]

[0069] In the embodiment, when the magnetron sputtering method is adopted, its parameter settings are as shown in Table 3:

[0070] Table 3

[0071]

[0072] Example 1

[0073] A passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer stacked together; the thermal radiation absorbing layer comprises:

[0074] Polyester, silica and hydrophobic graphene loaded on polyester.

[0075] The infrared radiation reflecting layer is an aluminum layer.

[0076] A method for preparing a passive radiation heating material comprises the following steps:

[0077] S1: Immerse polyester fabric (10 cm x 10 cm) in a graphene ethanol solution (1.0 mg / mL) containing tetraethyl orthosilicate (TEOS) (4 v / v%) and hexadecyltrimethoxysilane (HDTMS) (5 v / v%). Stir continuously at room temperature for 2 hours and gradually add ammonia aqueous solution (10 v / v%) until the reaction is complete. Ammonia catalysis triggers a hydrolysis-condensation reaction between TEOS and HDTMS, producing SiO2 on the polyester fabric. Remove the treated polyester fabric, dry it in air, and bake it in a vacuum oven at 130°C for 1 hour.

[0078] S2 uses magnetron sputtering to plate a metal aluminum layer on the surface of the fabric obtained in step S1 according to the following parameters to obtain the above-mentioned passive radiation heating material.

[0079] The flowchart of step S1 is as follows Figure 1 shown.

[0080] The flowchart of step S2 is as follows Figure 2 shown.

[0081] The passive radiation heating material obtained in Example 1 has a working schematic diagram as shown below: Figure 3 shown.

[0082] Example 2

[0083] The difference between Example 2 and Example 1 is that the concentration of the graphene ethanol solution is different, wherein the concentration of the graphene ethanol solution in Example 1 is 1.0 mg / mL, and the concentration of the graphene ethanol solution in Example 2 is 0.2 mg / mL.

[0084] A passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer which are stacked;

[0085] The components of the thermal radiation absorbing layer include:

[0086] Polyester, silica and hydrophobic graphene loaded on polyester.

[0087] The infrared radiation reflecting layer is an aluminum layer.

[0088] A method for preparing a passive radiation heating material comprises the following steps:

[0089] S1: Immerse polyester fabric (10 cm x 10 cm) in a graphene ethanol solution (0.2 mg / mL) containing tetraethyl orthosilicate (TEOS) (4 v / v%) and hexadecyltrimethoxysilane (HDTMS) (5 v / v%). Stir continuously at room temperature for 2 hours and gradually add ammonia aqueous solution (10 v / v%) until the reaction is complete. Ammonia catalysis triggers a hydrolysis-condensation reaction between TEOS and HDTMS, producing SiO2 on the polyester fabric. Remove the treated polyester fabric, dry it in air, and bake it in a vacuum oven at 130°C for 1 hour.

[0090] S2 uses magnetron sputtering to plate a metal aluminum layer on the surface of the fabric obtained in step S1 according to the following parameters to obtain the above-mentioned passive radiation heating material.

[0091] Example 3

[0092] The difference between Example 3 and Example 1 is that the concentration of the graphene ethanol solution is different, wherein the concentration of the graphene ethanol solution in Example 1 is 1.0 mg / mL, and the concentration of the graphene ethanol solution in Example 3 is 0.4 mg / mL.

[0093] A passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer which are stacked;

[0094] The components of the thermal radiation absorbing layer include:

[0095] Polyester, silica and hydrophobic graphene loaded on polyester.

[0096] The infrared radiation reflecting layer is an aluminum layer.

[0097] A method for preparing a passive radiation heating material comprises the following steps:

[0098] S1: Immerse polyester fabric (10 cm x 10 cm) in a graphene ethanol solution (0.4 mg / mL) containing tetraethyl orthosilicate (TEOS) (4 v / v%) and hexadecyltrimethoxysilane (HDTMS) (5 v / v%). Stir continuously at room temperature for 2 hours and gradually add ammonia aqueous solution (10 v / v%) until the reaction is complete. Ammonia catalysis triggers a hydrolysis-condensation reaction between TEOS and HDTMS, producing SiO2 on the polyester fabric. Remove the treated polyester fabric, dry it in air, and bake it in a vacuum oven at 130°C for 1 hour.

[0099] S2 uses magnetron sputtering to plate a metal aluminum layer on the surface of the fabric obtained in step S1 according to the following parameters to obtain the above-mentioned passive radiation heating material.

[0100] Example 4

[0101] The difference between Example 4 and Example 1 is that the concentration of the graphene ethanol solution is different. The concentration of the graphene ethanol solution in Example 1 is 1.0 mg / mL, and the concentration of the graphene ethanol solution in Example 4 is 0.6 mg / mL.

[0102] A passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer which are stacked;

[0103] The components of the thermal radiation absorbing layer include:

[0104] Polyester, silica and hydrophobic graphene loaded on polyester.

[0105] The infrared radiation reflecting layer is an aluminum layer.

[0106] A method for preparing a passive radiation heating material comprises the following steps:

[0107] S1: Immerse polyester fabric (10 cm x 10 cm) in a graphene ethanol solution (0.6 mg / mL) containing tetraethyl orthosilicate (TEOS) (4 v / v%) and hexadecyltrimethoxysilane (HDTMS) (5 v / v%). Stir continuously at room temperature for 2 hours and gradually add ammonia aqueous solution (10 v / v%) until the reaction is complete. Ammonia catalysis triggers a hydrolysis-condensation reaction between TEOS and HDTMS, producing SiO2 on the polyester fabric. Remove the treated polyester fabric, dry it in air, and bake it in a vacuum oven at 130°C for 1 hour.

[0108] S2 uses magnetron sputtering to plate a metal aluminum layer on the surface of the fabric obtained in step S1 according to the following parameters to obtain the above-mentioned passive radiation heating material.

[0109] Example 5

[0110] The difference between Example 5 and Example 1 is that the concentration of the graphene ethanol solution is different. The concentration of the graphene ethanol solution in Example 1 is 1.0 mg / mL, and the concentration of the graphene ethanol solution in Example 5 is 0.8 mg / mL.

[0111] A passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer which are stacked;

[0112] The components of the thermal radiation absorbing layer include:

[0113] Polyester, silica and hydrophobic graphene loaded on polyester.

[0114] The infrared radiation reflecting layer is an aluminum layer.

[0115] A method for preparing a passive radiation heating material comprises the following steps:

[0116] S1: Immerse polyester fabric (10 cm x 10 cm) in a graphene ethanol solution (0.8 mg / mL) containing tetraethyl orthosilicate (TEOS) (4 v / v%) and hexadecyltrimethoxysilane (HDTMS) (5 v / v%). Stir continuously at room temperature for 2 hours and gradually add ammonia aqueous solution (10 v / v%) until the reaction is complete. Ammonia catalysis triggers a hydrolysis-condensation reaction between TEOS and HDTMS, producing SiO2 on the polyester fabric. Remove the treated polyester fabric, dry it in air, and bake it in a vacuum oven at 130°C for 1 hour.

[0117] S2 uses magnetron sputtering to plate a metal aluminum layer on the surface of the fabric obtained in step S1 according to the following parameters to obtain the above-mentioned passive radiation heating material.

[0118] Performance testing:

[0119] The passive radiation heating materials obtained in Examples 1-5 were subjected to absorbance tests, and the test results are as follows: Figure 4 shown.

[0120] from Figure 4It can be seen that as the concentration of graphene increases, the surface temperature of the fabric increases accordingly. When 0.2 mg / mL graphene is added, the temperature of the heated fabric after 30 minutes of illumination is 35.0°C. When 0.6 mg / mL graphene is added, the temperature of the heated fabric after 30 minutes of illumination is 39.4°C. When 1.0 mg / mL graphene is added, the temperature of the heated fabric after 30 minutes of illumination is 42.0°C, and the illumination temperature value reaches the maximum. This is because as the concentration of graphene increases, the coverage of graphene adsorbed on the surface of the polyester fabric increases, thereby enhancing the photothermal effect performance of the fabric, causing the temperature of the heated fabric to rise under illumination conditions, increasing the heating effect, and as the concentration of graphene increases, the temperature change curve tends to be flat, so from a cost perspective, it is appropriate to select 1.0 mg / mL graphene.

[0121] The passive radiation heating material obtained in Example 1 was characterized by scanning electron microscopy. Figure 5 The characterization method is as follows: Under room temperature conditions, the fabric is observed using a field emission scanning electron microscope. First, the sample surface is sprayed with gold to make the sample conductive for observation under a field emission scanning electron microscope.

[0122] Figure 5 This is a scanning electron microscope image of the passive radiation heating material obtained in Example 1. Figure 5 (a) is a cross-sectional view of the passive radiant heating material, from which the double-layer structure of the finished fabric (PRHF) can be clearly seen. Figure 5 (b) is an electron microscope image of the aluminum layer (infrared radiation reflection layer) in the passive radiation heating material. The results show that the aluminum layer treated with magnetron sputtering is smooth and flat. Figure 5 (c) is an electron microscope image of the graphene layer (thermal radiation absorption layer) in the passive radiation heating material. The results show that the surface of the fabric treated with graphene is rough and is covered by the hexadecyltrimethoxysilane / silica hybrid product (HDTMS@SiO2) which is the product of the hydrolysis of TEOS and HDTMS. Figure 5 It can also be seen that the graphene layer and the aluminum layer are each produced only on one side of the fabric.

[0123] The passive radiation heating material obtained in Example 1 was subjected to X-ray photoelectron spectroscopy characterization test, and the test results are as follows: Figure 6 As shown. Among them, Figure 6 The orange line (top line) is a characterization diagram of the hydrophobic graphene side (thermal radiation absorbing layer) of the passive radiative heating material obtained in Example 1; the blue line (bottom line) is a characterization diagram of the aluminum side (infrared radiation reflecting layer) of the above material.

[0124] Figure 6 In the graphene layer, the representative Si 2p and Si 2s peaks appeared at 103.0 and 154.2 eV on the hydrophobic graphene side, while two peaks appeared at 72.5 and 118.1 eV on the aluminum sputtered side, which are the Al 2p and Al 2s peaks, respectively. The above results indicate that aluminum is deposited only on the fabric during magnetron sputtering.

[0125] The wavelength of radiation emitted by the human body is usually in the range of 7-14 μm, and there is an emission peak at a wavelength of about 9-10 μm. Therefore, the present invention tested the infrared reflectivity of the polyester fabric material and the passive radiation heating material obtained in Example 1. The results are as follows: Figure 7-8 ,in, Figure 7 For absorbance test, Figure 8 For infrared reflectivity test.

[0126] from Figure 7 As can be seen, within the visible light wavelength range, the passive radiant heating material obtained in Example 1, containing graphene, exhibits significantly greater absorbance than ordinary polyester fabric. Compared to ordinary polyester fabric, the passive radiant heating material obtained in Example 1 enhances its ability to reflect infrared waves emitted by the human body and absorb solar radiation, effectively reducing thermal radiation dissipation and enhancing the utilization of environmental thermal radiation.

[0127] from Figure 8 It can be seen that ordinary polyester fabric has a low reflectivity in the radiation wavelength range of 7-14 μm, while the passive radiant heating material obtained in Example 1 has a reflectivity of greater than 90% on the aluminum side closest to the skin, and polyester fabric exhibits minimal infrared reflectivity in this range. The oxygen-containing functional groups in graphene have been shown to enhance its absorption of solar heat radiation.

[0128] The thermal performance of the passive radiation heating material obtained in Example 1 was tested under light conditions. The test results are as follows: Figure 9 As a proof-of-concept experiment, in order to avoid the influence of heat conduction and convection on the experimental results, the present invention placed the sample in a 20.5℃ insulation chamber to study the radiant heating performance of the fabric, where the temperature of the heating stage simulating human skin was set to 32.0℃. Under this condition, the temperature between the skin and the sample was recorded using a multi-channel thermometer while heating the fabric. Figure 9 Compared to ordinary polyester fabric, the passive radiant heating material (i.e., radiant thermal fabric) obtained in Example 1 can raise the simulated skin temperature to 37.4°C, significantly exceeding the heating effect of other fabrics. To further quantify the heating performance of the textile, the thermal storage power (q) was calculated using a formula derived from the Stefan-Boltzmann law to characterize the fabric's heating performance.

[0129]

[0130] where ε is the emissivity of the human body (0.95), and σ is the Stefan-Boltzmann constant (5.67×10 -8 W m -2 K -4 ), T1 is the simulated skin side temperature under the fabric, and T2 is the simulated skin side temperature (32.0℃). The higher heat storage capacity indicates that more heat is stored between the simulated skin and the fabric. The q of the passive radiant heating fabric is 23.2W / m 2 , significantly higher than conventional fabrics.

[0131] The above test proves that the passive radiation heating material obtained in Example 1 has improved heating performance compared with ordinary textile materials. The principle can be used to Figure 10 The schematic diagram is used to illustrate. In this thermal management model, the metabolic heat generated by the human body and the environmental radiation heat are considered to be heat sources. Ordinary textiles have low reflectivity and absorbance of infrared (wavelength range 8-14μm), so a large amount of radiant heat passes through the fabric and dissipates into the surrounding environment. Passive radiation heating fabrics, on the other hand, have a graphene layer formed on the outside of the fabric to increase the absorption of radiant heat, and the addition of metal aluminum to the coating close to the skin enhances the reflectivity of human infrared. Therefore, a large amount of human radiation is reflected back to the skin side for absorption, while the external radiant heat is continuously absorbed, which greatly reduces the heat loss under the cover of the passive radiation heating fabric, and the heating effect is better than that of ordinary textiles.

[0132] The following test was conducted on the washability of the passive radiation heating material obtained in Example 1. The test results are as follows: Figure 11 The test method, based on AATCC 61, used an accelerated wash cycle to investigate the fabric's washability (water temperature set at 40°C, 0.37wt% soap powder and 10 stainless steel balls added to 200mL of distilled water). Each accelerated wash lasted 45 minutes, equivalent to five regular household machine washes. The water contact angle (WCA) on the coated side was measured after each wash. As shown in the figure, the photothermal effect temperature (PTE) on the graphene side slowly decreased from 43.5°C to 40.9°C after 50 washes. Clearly, the fabric surface is coated with SiO2, produced by the hydrolysis of HDTMS, which allows for graphene adsorption and excellent PTE performance even after the wash test. The gray curve (graphene-coated fabric) represents polyester fabric soaked only in 1.0mg / mL graphene. The PTE temperature measured before the wash test was 43.3°C, but dropped to 32.5°C after 50 washes. It can be seen that since the fabric surface is not wrapped with HDTMS and SiO2 hybrids, water washing will cause the graphene material on the fabric surface to fall off, resulting in the continuous weakening of the fabric's photothermal effect performance.

[0133] In summary, the passive radiant heating material of the present invention has excellent performance that not only helps improve people's wearing comfort and health, but also contributes to energy conservation and environmental sustainability. The passive radiant heating material of Example 1 of the present invention has at least the following advantages:

[0134] 1) The bubble stirring method is used to prepare hydrophobic graphene fabric to enhance the fabric's radiant heat absorption, and a metal aluminum layer is plated on one side using magnetron sputtering technology to suppress the loss of human body heat radiation, thereby realizing a fabric with outdoor human passive heating performance.

[0135] 2) The thermal management performance of passive radiation heating fabrics was investigated. The fabric was tested under light conditions to cover simulated skin and calculate the heat storage value. The results showed that compared with ordinary polyester fabrics, the heating fabrics have excellent heat storage performance and can effectively achieve outdoor human body heating.

[0136] 3) The effects of the washability of passive radiant heating fabrics on their photothermal effect were investigated. Results showed that after 50 washes, the photothermal effect temperature of the passive radiant heating fabrics showed a non-significant decrease, demonstrating the excellent durability of passive radiant heating fabrics.

[0137] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A passive radiation heating material, characterized in that: The passive radiation heating material comprises a thermal radiation absorbing layer and an infrared radiation reflecting layer provided on one side of the thermal radiation absorbing layer; The components of the thermal radiation absorbing layer include: A fiber material, and graphene supported on the fiber material and wrapped by a hybrid of silica and hexadecyltrimethoxysilane; The method for preparing the passive radiation heating material comprises the following steps: S1. Mixing a fiber material, tetraethyl orthosilicate, and hexadecyltrimethoxysilane in a graphene solution, stirring the mixture using a bubble stirring method, and adding an ammonia aqueous solution dropwise over 1-2 hours until the reaction is complete, thereby obtaining a treated fiber material. The treated fiber material is dried in air and baked in a vacuum oven at a temperature of 130-230° C. for 1-2 hours to obtain a modified fiber material. S2: providing an infrared radiation reflecting layer on the surface of the modified fiber material to obtain the passive radiation heating material; The volume concentration ratio of tetraethyl orthosilicate to hexadecyltrimethoxysilane is 4-8:5-10.

2. The passive radiation heating material according to claim 1, characterized in that: The passive radiation heating material has a reflectivity greater than 90% within a radiation wavelength range of 7-14 μm.

3. The passive radiation heating material according to claim 1, characterized in that: The infrared radiation reflecting layer includes at least one of an aluminum layer, a silver layer and a titanium layer.

4. A method for preparing a passive radiation heating material according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: mixing fiber material, tetraethyl orthosilicate and hexadecyltrimethoxysilane in a graphene solution, adding an ammonia solution, and reacting to obtain a modified fiber material; S2: providing an infrared radiation reflecting layer on the surface of the modified fiber material to obtain the passive radiation heating material.

5. The method according to claim 4, characterized in that: The concentration of the graphene solution is 1.0-2.0 mg / mL.

6. The method according to claim 4, wherein: The volume percentage of the ammonia solution is 10-20 v / v%.

7. The method according to claim 4, characterized in that: In step S2, an infrared radiation reflecting layer is formed on the surface of the modified fiber material by magnetron sputtering.

8. A fabric, characterized in that: The passive radiation heating material comprises the passive radiation heating material according to any one of claims 1 to 3.

Images