Heating and heat dissipation bidirectional personal heat management fabric and preparation method thereof

Abstract

The invention discloses a heating and heat dissipation bidirectional personal heat management fabric and a preparation method thereof, and belongs to the technical field of heat management fabric design. A photonic crystal coating with an amorphous structure is mainly sprayed on the surface of the fabric, so that the reflectivity of the fabric in a visible light near-infrared band and the emissivity of the fabric in a middle-infrared band are improved, and meanwhile, thermal-burden-free physical coloring is realized on the surface of the fabric, so that the requirements of diversification and attractiveness of the fabric are met; the other side of the fabric is coated with a low-emissivity MXene nanosheet, the passive radiation heating performance, the photothermal conversion performance and the Joule thermal performance of MXene are used for achieving heating thermal management of the fabric, dynamic personal thermal management is achieved through the fabric, the temperature of the fabric can be reduced by 10.2 DEG C in summer compared with the temperature of simulated human skin, and the temperature of the fabric can be reduced by 10.2 DEG C in summer. The temperature of 21.4 DEG C is increased in winter in combination with the multi-mode heating effect, and higher flexibility is provided for personal heat management under different environment conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management fabric design, and in particular relates to a personal thermal management fabric for heating and heat dissipation and a preparation method thereof. Background Art

[0002] Nowadays, climate change caused by extreme weather conditions and greenhouse effect caused by fossil fuel combustion poses a serious threat to human activities and public health. Extreme weather conditions such as scorching heat and severe cold have intensified the need for effective environmental temperature regulation, especially for outdoor workers. In addition, there is an urgent need to develop thermal management technologies that save energy and reduce carbon emissions to mitigate the increasingly frequent and severe extreme weather events. Personal thermal management (PTM) focuses on energy management in the human microenvironment and is an effective strategy to improve thermal comfort while reducing energy consumption.

[0003] Traditional chemical colors (including dyes and pigments) are generated by the absorption of the visible spectrum by the sun, which often increases the radiative heat load. How to strike a balance between the heating effect caused by color and the heat dissipation remains a major challenge. Unlike chemical colors, structural colors obtained by the interaction of sunlight with nanostructures do not bring additional heat input. Zhang et al. showed that a photonic film combined with a micro-pyramid array polymer mixed with random ceramic particles has excellent cooling performance [ACS Nano 2018, 12(4), 3095-3102]. It is worth noting that the synergistic effect of passive radiative cooling (PRC) properties and microstructural colors can significantly improve cooling performance by reducing heat absorption and dissipating excess heat. Therefore, microstructure-based photonic effects can be used to achieve colored surfaces that do not affect cooling performance, and even produce a positive net radiative cooling effect.

[0004] Most existing PTM fabrics can only achieve a single cooling or heat-insulating property due to the conflicting properties of mid-infrared emission and solar reflectivity in the passive radiative heating (PRH) region. Unlike cooling textiles, passive radiative heating materials require high solar absorptivity to achieve effective solar heating (SH) and have low emissivity in the mid-infrared region. However, since ambient temperature and solar radiation intensity fluctuate with climate change and diurnal cycles, it is difficult for such single-function materials to provide optimal comfort under different external conditions. Therefore, it is necessary to develop an advanced temperature-adaptive PTM technology that can adapt to ambient temperature and solar energy to achieve all-weather comfort, even in environments with large temperature differences between day and night. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a personal thermal management fabric with bidirectional heating and heat dissipation and a preparation method thereof, which mainly increases the reflectivity of the fabric in the visible light near-infrared band and the emissivity in the mid-infrared band by spraying a layer of photonic crystal coating with an amorphous structure on the surface of the fabric, and realizes physical coloring without heat burden on the surface of the fabric to meet the needs of textile diversification and aesthetics, and then sprays low-emissivity MXene nanosheets on the other side of the fabric, and utilizes the passive radiation heating performance, photothermal conversion performance and Joule heat performance of MXene to realize heating and heat dissipation bidirectional personal thermal management fabric, thereby obtaining the fabric. The fabric of the present invention realizes dynamic personal thermal management, realizes the heating effect of the fabric, and realizes the functions of warmth preservation and cooling, which is of great significance for personal comfort, energy efficiency and multi-scenario applications.

[0006] The invention provides a personal thermal management fabric with two-way heating and cooling, comprising: a fiber fabric substrate, an amorphous photonic crystal structure color coating arranged on one side of the fiber fabric substrate, and a nano material coating arranged on the other side of the fiber fabric substrate.

[0007] In one embodiment of the present invention, the fiber fabric substrate is one of polylactic acid fiber fabric, cotton fabric and polyester fiber fabric.

[0008] In one embodiment of the present invention, the nanomaterial coating serves as a heating layer to provide a heating mode for the thermal management fabric, and the amorphous photonic crystal structure color coating serves as a heat dissipation layer to provide a heat dissipation mode for the thermal management fabric. Both the heating mode and the heat dissipation mode of the thermal management fabric can be used separately.

[0009] In one embodiment of the present invention, the amorphous photonic crystal structural color coating is a mixture of SiO2 nano-microspheres, polymethyl methacrylate-methacrylic acid (PA) nano-particles, and nano-carbon black.

[0010] In one embodiment of the present invention, the particle size of SiO2 nanospheres is 180-300nm.

[0011] In one embodiment of the present invention, the nanomaterial is one or more of graphene, AgNWs, carbon nanotubes, and MXene nanosheets.

[0012] In one embodiment of the present invention, the thickness of the amorphous photonic crystal structural color coating is 100-200 μm, and the thickness of the nano material coating is 0.1-1.0 μm.

[0013] The present invention provides a method for preparing the above-mentioned heating and heat dissipation bidirectional personal thermal management fabric, which specifically comprises the following steps:

[0014] (1) subjecting the fiber fabric substrate to a hydrophilic treatment;

[0015] (2) mixing anhydrous ethanol, water, ammonia water, and tetraethyl orthosilicate in a volume ratio of 72:10:3:4-8, reacting, centrifuging, washing, and drying to obtain SiO2 microsphere powder; dispersing the SiO2 microsphere powder in deionized water, and sequentially adding PA nanoparticles and nano carbon black to prepare a SiO2 microsphere dispersion; finally, spraying the SiO2 microsphere dispersion onto the surface of a hydrophilized fiber fabric substrate, and curing;

[0016] (3) Ti3AlC2 was etched with a mixed solution of HCl and LiF, washed with deionized water until the pH of the supernatant was 5-7, and ultrasonic intercalation was performed followed by centrifugation to obtain a MXene dispersion, which was sprayed on the other side of the fiber fabric substrate and finally dried to obtain a personal thermal management fabric with a bidirectional heating and cooling function.

[0017] In one embodiment of the present invention, in step (2), the mass ratio of SiO2 microsphere powder, PA nanoparticles and nano carbon black is 90-110:1-3:0.5-1.5.

[0018] In one embodiment of the present invention, in step (2), the mass fraction of SiO2 microsphere powder in the SiO2 microsphere dispersion is 10-30%.

[0019] In one embodiment of the present invention, in step (2), the spraying process is 15-20 seconds per spraying with an interval of 5-10 seconds.

[0020] In one embodiment of the present invention, in step (3), the concentration of HCl is 8-10M, and the usage ratio of HCl, LiF, and Ti3AlC2 is 40mL:3.2-6.4g:2.0-4.0g.

[0021] In one embodiment of the present invention, in step (3), the ultrasonic intercalation solution is one or more of deionized water, anhydrous ethanol, N,N-dimethylformamide, dimethyl sulfoxide, and isopropanol.

[0022] In one embodiment of the present invention, in step (3), the mass fraction of the MXene dispersion is 10-30 mg / mL.

[0023] Beneficial effects:

[0024] (1) The present invention designs a colorful personal thermal management fabric with integrated cooling and multi-mode heating management, which is an asymmetric colorful fabric sprayed with a radiant cooling coating and a radiant heating coating, including a fiber fabric base, an amorphous photonic crystal structural color coating, and a coating constructed of low-emissivity nanomaterials. Therefore, the colorful personal thermal management fabric with asymmetric integrated cooling and multi-mode heating management can regulate the direction of heat transfer according to the ambient temperature or the needs of the wearer. It keeps warm in cold weather and dissipates heat in hot weather, thereby maintaining a suitable body temperature. The fabric of the present invention realizes dynamic personal thermal management, which can achieve a cooling of 10.2°C in summer compared to the temperature simulated by human skin, and a heating of 21.4°C in winter combined with a multi-mode heating effect, providing greater flexibility for personal thermal management under different environmental conditions.

[0025] (2) The colorful personal thermal management fabric with integrated cooling and multi-mode heating management designed by the present invention adopts photonic crystals and low-emissivity materials to prepare thermal management textiles. Through passive thermal management technologies such as radiation heat dissipation, heat reflection and heat storage, it does not rely on traditional energy consumption and reduces dependence on air conditioning and heating equipment, thereby significantly saving the consumption and use of fossil energy and promoting the development of the textile industry in a low-carbon and sustainable direction.

[0026] (3) The present invention designs a colorful personal thermal management fabric with integrated cooling and multi-mode heating management. Its heating mode consists of three modes: passive radiation heating, photothermal heating and electric heating. By integrating multiple heating methods, it can meet the thermal management needs in different scenarios, achieve precise temperature control and reduce energy consumption, and has the advantages of high efficiency and energy saving, intelligent flexibility and low carbon environmental protection.

[0027] (4) The colorful personal thermal management fabric with integrated cooling and multi-mode heating management designed by the present invention has good moisture permeability and effectively improves the wearing comfort. The amorphous photonic crystal structural color layer has super hydrophilicity, while the low-emissivity MXene nanosheet layer has a certain hydrophobicity. In summer, the moisture and heat on the skin surface can be quickly diffused to the structural color layer and evaporated, realizing the unidirectional transmission of moisture and heat from the inside to the outside, further optimizing the cooling thermal management effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The microscopic morphology of the amorphous photonic crystal structure in Example 1 is characterized, wherein (a, b) are the microsphere distribution on the surface of the amorphous photonic crystal fabric and (c) is the high-magnification amorphous photonic crystal fabric;

[0029] Figure 2 The figure is a schematic diagram of the radiation cooling principle of the amorphous photonic crystal structure (APC) in Example 1 (a), and its reflectivity in the visible near-infrared band and the emissivity curve in the mid-infrared band (b);

[0030] Figure 3 The transmittance and emissivity of the photonic crystal structure prepared for Example 1 and Comparative Example 1, wherein (a) is the transmittance and (b) is the emissivity;

[0031] Figure 4 The transmittance (a) of the thermal management fabrics of Example 1 and Comparative Example 1 in the visible near-infrared band and the emissivity (b) in the mid-infrared band are compared;

[0032] Figure 5 The microscopic morphology characterization of MXene-loaded polyester fabric (MXene / PET) in Example 2, wherein (a) is MXene / PET and (b) is high-fold MXene / PET;

[0033] Figure 6 The reflectivity curve of the MXene-loaded polyester fabric in the visible near-infrared band and the emissivity curve in the mid-infrared band of Example 2;

[0034] Figure 7 Flow chart of the preparation of the colorful personal thermal management (CMPC) fabric with integrated cooling and multi-mode heating management prepared in Example 3;

[0035] Figure 8 Characterization of the cross-sectional morphology of the colorful personal thermal management fabric with integrated cooling and multi-mode heating management prepared in Example 3, wherein (a) is the cross-sectional microscopic morphology of the CMPC fabric and (b) is the cross-sectional mapping diagram of the CMPC fabric;

[0036] Fig. 9 Reflectivity curves of the colored personal thermal management fabric with integrated cooling and multi-mode heating management prepared in Example 3 in the visible near-infrared band and the emissivity curves in the mid-infrared band (a); air permeability of the four fabrics (b);

[0037] Fig.10 The heating and cooling tests of the colored personal thermal management fabric with integrated cooling and multi-mode heating management prepared in Example 3 were carried out in an outdoor microenvironment, (a) is a schematic diagram of the microenvironment test device, (b) is a physical picture of the microenvironment test device, (c) is a cooling performance test of the colored personal thermal management fabric with integrated cooling and multi-mode heating management, (d) is a multi-mode heating performance test of the colored personal thermal management fabric with integrated cooling and multi-mode heating management;

[0038] Fig.11 The physical pictures (a, b) of the heat preservation and heat dissipation bidirectional personal thermal management fabric prepared in comparative example 2, and the physical picture (c) of the heat preservation and heat dissipation bidirectional personal thermal management fabric prepared in example 4;

[0039] Fig.12Comparison of transmittance (a) in the visible near-infrared band and emissivity (b) in the mid-infrared band of the colored personal thermal management fabrics with integrated cooling and multi-mode heating management prepared in Example 3, Example 4, and Example 5;

[0040] Fig.13 A comparison of the heating performance of the colorful personal thermal management fabrics with integrated cooling and multi-mode heating management prepared in Example 3 and Example 5 under outdoor conditions, wherein (a) is the fabric temperature change curve, (b) is the fabric temperature difference, and (c) is the ambient temperature and humidity. DETAILED DESCRIPTION

[0041] The test method used in the present invention is:

[0042] Characterization of sample micromorphology: The micromorphology, particle size and photonic crystal configuration of the microspheres were tested using a HITACHI SU8100 field emission scanning electron microscope (FESEM). The samples were pretreated before testing. For microsphere samples, they were dispersed in ultrapure water to prepare a microsphere dispersion, which was then dripped onto the surface of the silicon wafer and dried for testing; for photonic crystal film samples, they were directly cut and pasted on the sample platform for testing. Before testing, the sample platform must be gold-sprayed to improve the conductivity of the sample, and the operating voltage is 4KV.

[0043] Optical and radiation properties testing: The spectral properties testing of thermal insulation and heat dissipation personal thermal management fabrics includes the characterization of their transmission and reflection. The spectrum of the sunlight band (0.3-2.5μm) is characterized by a spectrophotometer, and the emissivity, reflectivity and absorptivity of the mid-infrared band are characterized by a Fourier infrared spectrometer in integrating sphere mode.

[0044] Outdoor heating and cooling performance test: Tested using a self-built micro-environment test chamber ( Fig.10 a, b), the test was conducted in Wuxi, Jiangsu Province, China (31°N, 120°E), 121W m -2 The heater and silicone rubber are used to simulate the daily heat dissipation behavior of human skin, and thermocouples are attached under the test samples to monitor the sample temperature in real time. At the same time, a weather station is set up to monitor the real-time ambient temperature, humidity, wind speed and light radiation intensity.

[0045] Air permeability test: According to the national standard (GB / T 13764), the moisture permeability of CMPC, APC / PET, MXene / PET and PET was tested by the positive cup evaporation method. A moisture permeability cup filled with distilled water and sealed with a fabric sample was placed in a sealed environment. The temperature and humidity of the sealed environment were 38±2℃ and 40±2%, respectively.

[0046] The particle size of the polymethyl methacrylate-methacrylic acid (PA) nanoparticles used below is 20-50 nm; the thickness of the structural color coating is 100-200 μm, and the thickness of the nanomaterial coating is 0.1-1.0 μm.

[0047] Example 1

[0048] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0049] (2) Adoption Monodisperse SiO2 microspheres were prepared by adding 10 mL of deionized water and 3 mL of ammonia water to 72 mL of anhydrous ethanol. After stirring and mixing at room temperature, 4 mL of tetraethyl orthosilicate was slowly added. After reacting for 8 hours, the SiO2 microsphere powder was obtained by centrifugal washing and drying. The SiO2 microsphere powder was dispersed in deionized water, and PA nanoparticles and nano-carbon black were added in sequence to prepare a microsphere dispersion, wherein the mass fraction of the microspheres was 20 wt %, and the mass ratio of SiO2 microsphere powder, PA nanoparticles and nano-carbon black in the microsphere dispersion was 100:2:1. Finally, the microsphere dispersion was sprayed onto the surface of the hydrophilized polyester fabric. The spraying process was 20 seconds per spray with an interval of 10 seconds, and the cured microspheres were treated in an oven at 80°C to obtain a fabric with cooling performance.

[0050] Figure 1 The microscopic morphology of the amorphous photonic crystal structure prepared by the spraying method, in which the SiO2 microsphere particle size is 208.7nm, showing a short-range ordered and long-range disordered distribution. The quasi-periodic structure of APC and visible light undergo multiple scattering to form photon pseudobands. Due to the large scattering intensity, the scattered light is relatively random and isotropic, corresponding to Figure 1 (c) is a circular distribution with central symmetry. Since light undergoes strong multiple scattering in the quasi-periodic distribution of APC, it can effectively improve the reflectivity of sunlight and enhance the scattering performance of infrared light band, thereby increasing radiation heat dissipation, such as Figure 2 As shown, the introduction of color based on physical structure not only does not increase the thermal burden of the thermal management fabric, but also helps to further improve the cooling effect, showing excellent radiative cooling performance.

[0051] Comparative Example 1

[0052] This comparative example is to prepare a colored radiation cooling fabric with a crystalline photonic crystal structure, and the specific preparation method is as follows:

[0053] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0054] (2) Adoption Monodisperse SiO2 microspheres were prepared by the method of adding 10 mL of deionized water and 3 mL of ammonia water to 72 mL of anhydrous ethanol. After stirring and mixing thoroughly at room temperature, 4 mL of tetraethyl orthosilicate was slowly added. After reacting for 8 hours, the mixture was centrifuged, washed, and dried for later use. SiO2 microsphere powder was dispersed in deionized water to prepare a microsphere dispersion liquid with a microsphere mass fraction of 1 wt%. A crystalline photonic crystal structure was constructed on the surface of polyester fabric by vertical deposition. The oven temperature was 60°C, the humidity was 50%, the deposition time was 36 hours, and the microspheres were treated in an oven at 80°C to stabilize the photonic crystal structure to obtain a fabric with cooling performance.

[0055] Figure 1 It is shown that the amorphous photonic crystal structure prepared by spray coating has quasi-periodicity. Figure 3 The photonic crystal structure prepared by vertical deposition method is highly ordered, and the microspheres are distributed in a regular hexagonal array. The corresponding fast Fourier transform diagram shows a hexagonal symmetrical lattice structure with anisotropy. In periodic photonic crystals, the light scattering intensity is weak and the scattering range is narrow, mainly concentrated in a specific wavelength region that matches its photon bandgap, thus showing weaker sunlight reflection performance and infrared radiation performance ( Figure 4 ).

[0056] Example 2

[0057] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0058] (2) MXene nanosheets were prepared by MILD method. 3.2 g lithium fluoride was added to 40 mL 9 M HCl. After stirring at room temperature for 5-10 min, 2.0 g Ti3AlC2 powder was slowly added. After etching for 24 h, the supernatant was washed with deionized water until the pH value was ~6. Ultrasonic intercalation was performed at 5-8 °C. The ultrasonic intercalation solvent was deionized water. The MXene dispersion was obtained by centrifugation at 3500 rpm for 5 min. 20 mg / mL MXene dispersion was sprayed on one side of the polyester fabric and dried in an oven at 60 °C to obtain a fabric with thermal insulation properties.

[0059] like Figure 5 As shown in the figure, the MXene nanosheets prepared by the MILD method are evenly distributed on the surface of the polyester fabric. The prepared MXene / PET fabric shows excellent sunlight absorption ability, and the low emissivity of MXene itself gives MXene / PET excellent radiation heating performance ( Figure 6 ).

[0060] Example 3

[0061] A personal thermal management fabric with two-way heating and cooling, comprising: a polyester fabric substrate, an amorphous photonic crystal structural color coating composed of a mixture of SiO2 nano-microspheres, polymethyl methacrylate-methacrylic acid (PA) nanoparticles, and nano-carbon black arranged on one side of the polyester fabric substrate, and a coating composed of MXene nanosheets arranged on the other side of the polyester fabric substrate. The specific preparation method is as follows: Figure 7 As shown:

[0062] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0063] (2) Adoption The monodisperse SiO2 microspheres (particle size of 242 nm) were prepared by adding 10 mL of deionized water and 3 mL of ammonia water to 72 mL of anhydrous ethanol, stirring and mixing at room temperature, and then slowly dropping 7 mL of tetraethyl orthosilicate. After reacting for 8 h, the SiO2 microsphere powder was centrifuged, washed, and dried. The SiO2 microsphere powder was dispersed in deionized water, and PA nanoparticles and nano-carbon black were added in sequence to prepare a microsphere dispersion, wherein the mass fraction of the microspheres was 20 wt %, and the mass ratio of SiO2 microsphere powder, PA nanoparticles, and nano-carbon black in the microsphere dispersion was 100:3:1. The microsphere dispersion was sprayed onto the surface of the hydrophilized polyester fabric. The spraying process parameters were as follows: each spray was 20 s, with an interval of 5 s, and the cured microspheres were treated in an oven at 80 ° C.

[0064] (3) MXene nanosheets were prepared by MILD method. 3.2 g lithium fluoride was added to 40 mL 9 M HCl. After stirring at room temperature for 5-10 min, 2.0 g Ti3AlC2 powder was slowly added. After etching for 24 h, the supernatant was washed with deionized water until the pH value of the supernatant was ~6. Ultrasonic intercalation was performed at 5-8 °C. The ultrasonic intercalation solvent was deionized water. The MXene dispersion was obtained by centrifugation at 3500 rpm for 5 min. The MXene dispersion with a mass fraction of 30 mg / mL was sprayed on the other side of the polyester fabric and dried in an oven at 60 °C to obtain a colorful personal thermal management fabric (CMPC) with integrated cooling and multi-mode heating management.

[0065] from Figure 8 The structure of the colorful personal thermal management fabric with integrated cooling and multi-mode heating management can be clearly seen in the cross-sectional SEM image of (a). Figure 8The mapping distribution of (b) further shows the structural distribution of the fabric. The Si element is distributed in the upper layer, and the Ti element is distributed in the lower layer, which can be attributed to SiO2 APC and MXene, respectively. Fig. 9 As shown in (a), the two sides of the prepared colorful personal thermal management fabric with integrated cooling and multi-mode heating management present different optical properties, with high solar reflectivity (79.85%) and high emissivity (92.03%) in the SiO2 APC cooling layer, and high solar absorptivity (80.33%) and low emissivity (18.24%) in the MXene heating layer. Fig. 9 As shown in (b), the prepared heat preservation and heat dissipation two-way personal thermal management fabric has good air permeability, and its water vapor transmission rate is tested to be 3722.2 gm -2 day -1 , showing good wearing comfort.

[0066] use Fig.10 The devices shown in (a) and (b) further characterize the cooling and heating effects of CMPC fabrics in microenvironments. The results show that Fig.10 As shown in (c), in the cooling mode, the surface temperature of the CMPC fabric is significantly lower than that of the simulated skin and ordinary cotton fabric, showing a good cooling effect; Fig.10 As shown in (d), in the heating mode, the surface temperature of the CMPC fabric is 21.4℃ and 28.5℃ higher than that of the simulated skin and ordinary cotton fabric by synergistically controlling the three heating modes of the heating layer, namely, passive radiation heating, photothermal performance and electric heating performance. This shows that the prepared colorful personal thermal management fabric with integrated cooling and multi-mode heating management can adapt to the changes in ambient temperature or human needs to change its own thermal management mode and regulate the direction of heat transfer. It can keep warm in cold weather and dissipate heat in hot weather, thereby maintaining a suitable body temperature.

[0067] Example 4

[0068] A personal thermal management fabric for heating and cooling bidirectionally comprises: a polyester fabric substrate, an amorphous photonic crystal structural color coating composed of a mixture of SiO2 nano-microspheres, polymethyl methacrylate-methacrylic acid (PA) nanoparticles, and nano-carbon black disposed on one side of the polyester fabric substrate, and a coating composed of MXene nanosheets disposed on the other side of the polyester fabric substrate. The preparation method comprises:

[0069] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0070] (2) Adoption The monodisperse SiO2 microspheres (particle size of 242nm) were prepared by adding 10mL of deionized water and 3mL of ammonia water to 72mL of anhydrous ethanol, stirring and mixing at room temperature, slowly adding 7mL of tetraethyl orthosilicate, reacting for 8h, centrifuging, washing, and drying for use, dispersing SiO2 microsphere powder in deionized water, adding PA nanoparticles and nano-carbon black in sequence to prepare a microsphere dispersion, wherein the mass fraction of microspheres is 30wt%, and the mass ratio of SiO2 microsphere powder, PA nanoparticles and nano-carbon black in the microsphere dispersion is 100:2:1, spraying the microsphere dispersion onto the surface of hydrophilized polyester fabric, and the spraying process parameters are spraying for 20s each time with an interval of 5s, and curing the microspheres in an oven at 80°C;

[0071] (3) MXene nanosheets were prepared by MILD method. The specific preparation method was as follows: 3.2 g lithium fluoride was added to 40 mL 9 M HCl, and after stirring at room temperature for 5-10 min, 2.0 g Ti3AlC2 powder was slowly added. After etching for 24 h, the supernatant was washed with deionized water until the pH value was ~6, and ultrasonic intercalation was performed at 5-8 °C. The ultrasonic intercalation solvent was deionized water. The MXene dispersion was obtained by centrifugation at 3500 rpm for 5 min. The MXene dispersion with a mass fraction of 10 mg / mL was sprayed on the other side of the polyester fabric, and dried in an oven at 60 °C to obtain a colorful personal thermal management fabric with integrated cooling and multi-mode heating management.

[0072] Comparative Example 2

[0073] A personal thermal management fabric capable of heating and cooling in both directions, comprising: a polyester fabric substrate, an amorphous photonic crystal structure color coating composed of SiO2 nano-microspheres disposed on one side of the polyester fabric substrate, and a coating composed of MXene nanosheets disposed on the other side of the polyester fabric substrate, wherein the preparation method comprises:

[0074] (4) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0075] (5) Adoption The monodisperse SiO2 microspheres (particle size of 242nm) were prepared by adding 10mL of deionized water and 3mL of ammonia water to 72mL of anhydrous ethanol, stirring and mixing at room temperature, slowly adding 7mL of tetraethyl orthosilicate, reacting for 8h, centrifuging, washing, and drying for use, dispersing SiO2 microsphere powder and nano-carbon black in deionized water, wherein the mass fraction of microspheres is 30wt%, ensuring that the mass fraction of SiO2 microspheres to nano-carbon black is 100:1, spraying the microsphere dispersion onto the surface of hydrophilized polyester fabric, the spraying process parameters are spraying for 20s each time, with an interval of 5s, and curing the microspheres in an oven at 80°C;

[0076] (6) MXene nanosheets were prepared by MILD method. The specific preparation method was as follows: 3.2 g lithium fluoride was added to 40 mL 9 M HCl, and after stirring at room temperature for 5-10 min, 2.0 g Ti3AlC2 powder was slowly added. After etching for 24 h, the supernatant was washed with deionized water until the pH value was ~6, and ultrasonic intercalation was performed at 5-8 °C. The ultrasonic intercalation solvent was deionized water. The MXene dispersion was obtained by centrifugation at 3500 rpm for 5 min. The MXene dispersion with a mass fraction of 10 mg / mL was sprayed on the other side of the polyester fabric, and dried in an oven at 60 °C to obtain a colorful personal thermal management fabric with integrated cooling and multi-mode heating management.

[0077] like Fig.11 As shown in (a, b), in the process of preparing the CMPC fabric in Comparative Example 2, when no PA binder was added to the microsphere dispersion, applying an indentation or scratch on the fabric surface would cause the APC structure to be damaged and the structural color to disappear, while the CMPC fabric in Example 4 had almost no surface damage after applying scratches and indentations ( Fig.11 c).

[0078] Example 5

[0079] A heat preservation and heat dissipation bidirectional personal thermal management fabric comprises: a polyester fabric substrate, an amorphous photonic crystal structural color coating composed of a mixture of SiO2 nano-microspheres, polymethyl methacrylate-methacrylic acid (PA) nanoparticles, and nano-carbon black arranged on one side of the polyester fabric substrate, and a coating composed of MXene nanosheets arranged on the other side of the polyester fabric substrate. The preparation method comprises:

[0080] (1) placing the polyester fabric washed with deionized water in an ethanol solvent to treat the surface of the fabric, dissolving the oil stains and chemical residues on the surface of the fabric, exposing the hydrophilic groups, and drying in an oven at 60° C. for later use;

[0081] (2) Adoption The monodisperse SiO2 microspheres (particle size of 294 nm) were prepared by adding 10 mL of deionized water and 3 mL of ammonia water to 72 mL of anhydrous ethanol, stirring and mixing at room temperature, and then slowly dropping 8 mL of tetraethyl orthosilicate. After reacting for 8 h, the mixture was centrifuged, washed, and dried for later use. The SiO2 microsphere powder was dispersed in deionized water, and PA nanoparticles and nano-carbon black were added in sequence to prepare a microsphere dispersion, wherein the mass fraction of the microspheres was 20 wt %, and the mass ratio of SiO2 microsphere powder, PA nanoparticles, and nano-carbon black in the microsphere dispersion was 100:2:1. The microsphere dispersion was sprayed onto the surface of the hydrophilized polyester fabric, and the spraying process parameters were spraying for 20 s each time with an interval of 10 s, and the cured microspheres were treated in an oven at 80 ° C.

[0082] (3) MXene nanosheets were prepared by MILD method. The specific preparation method was as follows: 3.2 g lithium fluoride was added to 40 mL 9 M HCl, and after stirring at room temperature for 5-10 min, 2.0 g Ti3AlC2 powder was slowly added. After etching for 24 h, the supernatant was washed with deionized water until the pH value was ~6, and ultrasonic intercalation was performed at 5-8 °C. The ultrasonic intercalation solvent was deionized water. The MXene dispersion was obtained by centrifugation at 3500 rpm for 5 min. The MXene dispersion with a mass fraction of 20 mg / mL was sprayed on the other side of the polyester fabric, and dried in an oven at 60 °C to obtain a colorful personal thermal management fabric with integrated cooling and multi-mode heating management.

[0083] Fig.12 The solar absorptivity and infrared emissivity of CMPC fabrics with different MXene loadings are shown in Figure 2. The results show that with the increase of MXene loading, the solar absorptivity does not change significantly. The weighted absorptivity of CMPC fabrics with MXene loadings of 10 mg / mL (Example 4), 20 mg / mL (Example 5) and 30 mg / mL (Example 3) in the visible and near-infrared bands are 80.55%, 80.56%, and 80.33%, respectively, while the emissivity shows a trend of first increasing and then decreasing with increasing loading. This is because when the coating thickness reaches a certain level, the surface smoothness of the material increases, resulting in more electromagnetic waves in the mid-infrared band being absorbed rather than reflected, showing a change in reduced emissivity. Fig.13 The heating performance of CMPC fabrics with loading amounts of 20 mg / mL and 30 mg / mL in outdoor environments was compared. The results showed that CMPC fabrics with a loading amount of 20% and low emissivity showed better heating performance, and the average temperature was higher than that of CMPC fabrics with a loading amount of 30 mg / mL. However, the increase in loading amount can lead to a significant increase in electrothermal performance. Therefore, CMPC fabrics with a MXene loading amount of 30 mg / mL were finally selected as the optimal dosage to prepare personal thermal management fabrics with better heating effects.

[0084] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A personal thermal management fabric with two-way heating and cooling, characterized in that: include: A fiber fabric substrate, an amorphous photonic crystal structure color coating arranged on one side of the fiber fabric substrate, and a nano material coating arranged on the other side of the fiber fabric substrate.

2. The heating and cooling bidirectional personal thermal management fabric according to claim 1, characterized in that: The fiber fabric substrate is one of polylactic acid fiber fabric, cotton fabric, and polyester fiber fabric; the amorphous photonic crystal structural color coating is a mixture of SiO2 nano-microspheres, polymethyl methacrylate-methacrylic acid nanoparticles, and nano-carbon black; the nanomaterial is one or more of graphene, AgNWs, carbon nanotubes, and MXene nanosheets.

3. The heating and cooling bidirectional personal thermal management fabric according to claim 1, characterized in that: The nanomaterial coating serves as a heating layer to provide a heating mode for the thermal management fabric, and the amorphous photonic crystal structure color coating serves as a heat dissipation layer to provide a heat dissipation mode for the thermal management fabric. Both the heating mode and the heat dissipation mode of the thermal management fabric can be used separately.

4. The heating and cooling bidirectional personal thermal management fabric according to claim 1, characterized in that: The thickness of the amorphous photonic crystal structural color coating is 100-200 μm, and the thickness of the nano material coating is 0.1-1.0 μm.

5. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to any one of claims 1 to 4, characterized in that: The steps include: (1) subjecting the fiber fabric substrate to a hydrophilic treatment; (2) mixing anhydrous ethanol, water, ammonia water and tetraethyl orthosilicate to react, centrifuging, washing and drying to obtain SiO2 microsphere powder; dispersing the SiO2 microsphere powder in deionized water, and sequentially adding polymethyl methacrylate-methacrylic acid nanoparticles and nano carbon black to prepare SiO2 microsphere dispersion; finally, spraying the SiO2 microsphere dispersion onto the surface of the hydrophilized fiber fabric substrate and curing; (3) Ti3AlC2 was etched with a mixed solution of HCl and LiF, washed with deionized water until the pH of the supernatant was 5-7, and ultrasonic intercalation was performed followed by centrifugation to obtain a MXene dispersion, which was sprayed on the other side of the fiber fabric substrate and finally dried to obtain a personal thermal management fabric with a bidirectional heating and cooling function.

6. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to claim 5, characterized in that: In step (2), the volume ratio of anhydrous ethanol, water, ammonia water and tetraethyl orthosilicate is 72:10:3:4-8; the mass ratio of SiO2 microsphere powder, polymethyl methacrylate-methacrylic acid nanoparticles and nano carbon black is 90-110:1-3:0.5-1.

5.

7. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to claim 5, characterized in that: In step (2), the mass fraction of SiO2 microsphere powder in the SiO2 microsphere dispersion is 10-30%.

8. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to claim 5, characterized in that: In step (3), the concentration of HCl is 8-10M; the usage ratio of HCl, LiF, and Ti3AlC2 is 40mL:3.2-6.4g:2.0-4.0g.

9. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to claim 5, characterized in that: In step (3), the ultrasonic intercalation solution is one or more of deionized water, anhydrous ethanol, N,N-dimethylformamide, dimethyl sulfoxide, and isopropanol.

10. The method for preparing the heating and cooling bidirectional personal thermal management fabric according to claim 5, characterized in that: In step (3), the mass fraction of the MXene dispersion is 10-30 mg / mL.

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