Aramid fabric as well as preparation method and application thereof

Abstract

The invention discloses an aramid fabric as well as a preparation method and application thereof. Comprising an aramid fabric substrate; a graphene hydrophobic layer I and a graphene hydrophobic layer II are respectively arranged on two surfaces of the aramid fabric substrate; a nano aluminum oxide coating is arranged on the surface of the graphene hydrophobic layer I. The preparation method comprises the following steps: firstly, arranging graphene hydrophobic layers on two surfaces of an aramid fabric substrate; and a nanometer aluminum oxide coating is arranged on the surface of one graphene hydrophobic layer. A Janus structure is formed by the nanometer aluminum oxide coating (hydrophilic layer) and the graphene hydrophobic layer, and the excellent dual functions of passive radiation cooling and sweat directional transmission / evaporation are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of textiles, and more particularly to an aramid fabric and its preparation method and application. Background Art

[0002] With global warming, the thermal comfort of outdoor workers in high-temperature environments has become an important issue. Traditional cooling methods (such as air conditioners and fans) are energy-intensive and not suitable for outdoor environments. Passive daytime radiative cooling (PDRC) technology, which reflects sunlight and radiates heat into outer space without external energy input, has become a promising solution. However, existing PDRC materials are mostly organic materials, which are vulnerable to ultraviolet light and cause secondary pollution, and are difficult to use in extreme environments.

[0003] Currently, most of the technologies for preparing passive radiative cooling fabrics have disadvantages such as strict preparation methods, high costs, long time consumption, and single functions (resulting in limited applications in high-temperature and high-humidity environments), making it difficult to achieve industrial production.

[0004] Therefore, it is necessary to develop a fabric that can achieve efficient passive cooling and sweat evaporation management and is suitable for personal thermal management in extreme environments. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in the first aspect of the present invention, an aramid fabric is provided, which can achieve the dual functions of excellent passive radiative cooling and sweat directional transport / evaporation.

[0006] In the second aspect of the present invention, a preparation method of the aramid fabric is further provided.

[0007] In the third aspect of the present invention, an application of the aramid fabric is further provided.

[0008] According to an embodiment of the first aspect of the present invention, an aramid fabric is provided; it includes an aramid fabric substrate; a graphene hydrophobic layer I and a graphene hydrophobic layer II are respectively provided on two surfaces of the aramid fabric substrate; a nano-aluminum oxide coating is provided on the surface of the graphene hydrophobic layer I.

[0009] According to a preferred embodiment of the present invention, the raw materials in the graphene hydrophobic layer I and the graphene hydrophobic layer II independently include HDTMS. Thus, on the one hand, HDTMS provides excellent hydrophobic performance; on the other hand, it improves the binding force between graphene and the substrate and prevents graphene from peeling off the substrate surface.

[0010] According to a preferred embodiment of the present invention, the thickness of the nano-aluminum oxide coating is 10-20 μm. For example, it includes 10 μm, 12 μm, 15 μm, 16 μm, 18 μm, 20 μm or a sub-range composed of any two of these values. Thus, when the thickness of the nano-aluminum oxide coating is within the range defined by the present invention, the aramid fabric has good unidirectional moisture conduction ability.

[0011] The aramid fabric provided by the embodiment of the present invention has at least the following beneficial effects:

[0012] In the present invention, graphene hydrophobic layers are first provided on both surfaces of the aramid fabric substrate; then a nano-aluminum oxide coating is provided on the surface of one of the graphene hydrophobic layers. The nano-aluminum oxide coating (hydrophilic layer) and the graphene hydrophobic layer form a Janus structure, realizing the dual functions of excellent passive radiative cooling and sweat directional transport / evaporation. This is because the high solar reflectivity of the nano-aluminum oxide coating (which can effectively reflect visible light and near-infrared light in sunlight, thereby reducing the absorption of solar radiation by the fabric) effectively reduces the surface temperature of the fabric. In indoor and outdoor environments, the high infrared emissivity and high thermal conductivity of graphene can quickly conduct the heat generated by the human body to the fabric surface.

[0013] Furthermore, the nano-aluminum oxide coating and the graphene hydrophobic layer can significantly enhance the high-temperature and high-humidity resistance performance. The synergistic effect of alumina and graphene improves the flame-retardant level of the fabric, making it suitable for extreme environments.

[0014] According to the second aspect of the present invention, a method for preparing an aramid fabric is provided, including the following steps:

[0015] S1. Mix graphene, a dispersant, and water to obtain a graphene suspension; mix the aramid fabric and the graphene suspension, soak and dry to obtain intermediate I;

[0016] S2. Mix the intermediate I, HDTMS (hexadecyltrimethoxysilane), an alkali, and solvent I, and then dry to obtain intermediate II;

[0017] S3. Mix a crosslinking agent, nano-Al2O3, a thickening agent, and solvent II to obtain a slurry; coat the slurry on one surface of the intermediate II, and dry to obtain the aramid fabric.

[0018] According to a preferred embodiment of the present invention, in step S3, based on the total mass of the slurry, the content of the nano-Al2O3 is 2%-8%.

[0019] According to a preferred embodiment of the present invention, in step S1, the soaking time is 0.5-3 h.

[0020] According to a preferred embodiment of the present invention, in step S1, calculated based on the total mass of the graphene suspension, the content of the graphene is 1% to 5%.

[0021] According to a preferred embodiment of the present invention, the crosslinking agent includes at least one of polyethylene glycol dimethacrylate (PEGDMA), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), and pentaerythritol triacrylate (PETA).

[0022] According to a preferred embodiment of the present invention, the thickening agent includes at least one of cationic starch, carboxymethyl starch (CMS), carboxymethyl cellulose (CMC), and hydroxyethyl starch (HES).

[0023] According to a preferred embodiment of the present invention, in step S1, the dispersant includes at least one of sodium dodecylbenzenesulfonate (SDBS), dispersant NNO, and sodium dodecyl sulfate (SDS).

[0024] According to a preferred embodiment of the present invention, calculated based on the total mass of the graphene suspension, the content of the dispersant is 0.2 - 0.8%.

[0025] According to a preferred embodiment of the present invention, calculated based on the total mass of intermediate I, HDTMS, base, and solvent I, the content of HDTMS is 2% - 10%.

[0026] According to a preferred embodiment of the present invention, calculated based on the total mass of the slurry, the content of the crosslinking agent is 7% - 10%.

[0027] According to a preferred embodiment of the present invention, calculated based on the total mass of the slurry, the content of the thickening agent is 2% - 4%.

[0028] According to a preferred embodiment of the present invention, the solvent I includes ethanol.

[0029] According to a preferred embodiment of the present invention, the solvent II includes ethanol and water.

[0030] According to a preferred embodiment of the present invention, in steps S1 and S2, the drying refers to vacuum drying, and the drying temperature is 80 - 150°C.

[0031] The third aspect of the present invention provides an application of the aramid fabric described in the first aspect of the present invention in the preparation of outdoor textiles.

[0032] According to a preferred embodiment of the present invention, the outdoor textiles include outdoor clothing.

[0033] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. Brief Description of the Drawings

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 is a schematic diagram of the preparation method of Embodiment 1 of the present invention. Detailed Embodiments

[0036] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0037] The reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the technical field, unless otherwise specified.

[0038] Some raw materials in the embodiments and comparative examples of the present invention are as follows:

[0039] Aramid fabric: Guangdong Sovetl Special Wire & Belt Co., Ltd.

[0040] Graphene: Carbon Feng graphene brand of Suzhou Carbon Feng Graphene Technology Co., Ltd.

[0041] Nano-aluminum oxide: Macklin brand of Guangzhou Rentai Technology Co., Ltd.

[0042] HDTMS (hexadecyltrimethoxysilane): Aladdin brand of Shanghai Aladdin Biochemical Technology Co., Ltd.

[0043] PEGDMA (polyethylene glycol dimethacrylate): Macklin brand of Shanghai Macklin Biochemical Technology Co., Ltd.

[0044] Embodiment 1

[0045] This example provides an aramid fabric, including an aramid fabric substrate; graphene hydrophobic layer I and graphene hydrophobic layer II are respectively provided on two surfaces of the aramid fabric substrate; a nano-aluminum oxide coating is provided on the surface of graphene hydrophobic layer I, and the thickness of the aluminum oxide coating is 15 μm. The schematic diagram of the preparation steps is as Figure 1 shown, and the steps are as follows:

[0046] S1. Dissolve graphene (2 wt%) and dispersant (0.6 wt%) in deionized water by mass percentage to prepare a graphene suspension. Then, magnetically stir the graphene suspension for 40 min. Subsequently, immerse the aramid fabric in the graphene suspension for 30 min, and then vacuum dry it at 130 °C for 1 h to obtain Intermediate I.

[0047] S2. Mix ammonia water (2 wt.%) and anhydrous ethanol solution (10 wt.%) and magnetically stir for 10 min, then add HDTMS (8 wt.%), and continue stirring for 30 min; then immerse Intermediate I in the prepared solution for 1 hour, and then vacuum dry it at 135 °C for 3 hours to obtain Intermediate II.

[0048] S3. Mix PEGDMA (9 wt.%), nano-Al2O3 (6 wt.%), cationic starch (3 wt.%) and C2H5OH (15 wt.%) with distilled water, and stir for 40 min to generate a coating slurry. Coat the slurry on one side of Intermediate II by the Meyer rod coating method, and finally obtain the aramid fabric by pre-drying the coated sample at 60 °C for 5 minutes and pre-drying at 170 °C for 40 s.

[0049] Example 2

[0050] This example provides an aramid fabric, whose composition and preparation method are the same as those in Example 1, except that the content of nano-Al2O3 is 2%.

[0051] Example 3

[0052] This example provides an aramid fabric, whose composition and preparation method are the same as those in Example 1, except that the content of nano-Al2O3 is 4%.

[0053] Example 4

[0054] This example provides an aramid fabric, whose composition and preparation method are the same as those in Example 1, except that the content of nano-Al2O3 is 8%.

[0055] Example 5

[0056] Change the dosage of HDTMS to 2 wt.%, and the other steps are the same as those in Example 1 to obtain a Janus aramid fabric.

[0057] Example 6

[0058] Change the content of HDTMS to 6 wt.%, and the other steps are the same as those in Example 1 to obtain a Janus aramid fabric.

[0059] Example 7

[0060] Change the content of HDTMS to 10 wt.%, and keep other steps the same as those in Example 1 to obtain a Janus aramid fabric.

[0061] Example 8

[0062] This example provides an aramid fabric, which has the same composition and preparation method as that in Example 1, except that the soaking time in step S1 is 1 h.

[0063] Example 9

[0064] This example provides an aramid fabric, which has the same composition and preparation method as that in Example 1, except that the soaking time in step S1 is 1.5 h.

[0065] Example 10

[0066] This example provides an aramid fabric, which has the same composition and preparation method as that in Example 1, except that the soaking time in step S1 is 2.0 h.

[0067] Comparative Example 1

[0068] Comparative Example 1 provides an aramid fabric, which has the same components and preparation method as that in Example 1, except that step S3 is missing.

[0069] Comparative Example 2

[0070] This example provides an aramid fabric substrate without any treatment.

[0071] Performance Test

[0072] The aramid fabrics prepared in the examples and comparative examples of the present invention are tested as follows:

[0073] 1. According to AATCC 195-2009, use a moisture management tester (MMT, G290, QINSUN, China) to evaluate the moisture transferability of the fabric; including the overall liquid moisture management capacity (OMMC) and the cumulative one-way transfer capacity (AOTC); among them, if AOTC is a positive value, it represents the ability of one-way moisture conduction, and the larger the value, the stronger the ability; on the contrary, if it is a negative value, it represents the lack of one-way moisture conduction ability.

[0074] 2. Measurement method for the flame retardancy of aramid fabrics:

[0075] According to GB / 16172, use a VOUCH6810 cone calorimeter to evaluate the flame retardancy of the material.

[0076] 3. Test method for the passive radiative cooling effect of aramid fabrics:

[0077] Conduct a thermal management experiment on the aramid fabric. The thermal management experiment includes the following steps:

[0078] 1) Cut aramid fabric with a length and width of 8 cm × 8 cm;

[0079] 2) Place the fabric on a heating table with a simulated skin temperature, use a xenon lamp to simulate a solar light source with a power density ≥ 1 kW / m 2 , and connect a thermocouple to detect the temperature change inside the fabric in real time, and record the temperature after stabilization. The test results are shown in Table 1.

[0080] Table 1

[0081]

[0082] It can be seen from the data in Table 1 that the aramid fabrics prepared in Examples 1-4 all have the effects of unidirectional moisture conduction, passive radiative cooling, and improved flame retardancy.

[0083] The above has made a detailed description in conjunction with the embodiments of the present invention, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can also be made without departing from the purpose of the present invention.

Claims

1. An aramid fabric, characterized in that, It includes an aramid fabric substrate; a graphene hydrophobic layer I and a graphene hydrophobic layer II are respectively provided on two surfaces of the aramid fabric substrate; a nano-aluminum oxide coating is provided on the surface of the graphene hydrophobic layer I.

2. The aramid fabric according to claim 1, wherein The thickness of the nano-aluminum oxide coating is 10 - 20 μm.

3. The aramid fabric according to claim 1, wherein The raw materials in the graphene hydrophobic layer I and the graphene hydrophobic layer II independently include HDTMS.

4. A method for preparing an aramid fabric according to any one of claims 1 to 3, characterized in that, It includes the following steps: S1. Mix graphene, a dispersant and water to obtain a graphene suspension; mix and soak the aramid fabric and the graphene suspension, and dry to obtain intermediate I; S2. Mix the intermediate I, HDTMS, an alkali and a solvent I, and then dry to obtain intermediate II; S3. Mix a cross-linking agent, nano-Al2O3, a thickener and a solvent II to obtain a slurry; coat the slurry on one surface of the intermediate II, and dry to obtain the aramid fabric.

5. The preparation method according to claim 4, wherein In step S3, calculated based on the total mass of the slurry, the content of the nano-Al2O3 is 2% - 8%.

6. The preparation method according to claim 4, wherein In step S1, the soaking time is 0.5 h - 3 h.

7. The preparation method according to claim 4, characterized in that, In step S1, calculated based on the total mass of the graphene suspension, the content of the graphene is 1% - 5%.

8. The preparation method according to claim 4, characterized in that, The cross-linking agent includes at least one of polyethylene glycol dimethacrylate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and pentaerythritol triacrylate.

9. The preparation method according to claim 4, characterized in that, The thickener includes at least one of cationic starch, carboxymethyl starch, carboxymethyl cellulose, and hydroxyethyl starch.

10. The application of the aramid fabric according to any one of claims 1 - 3 in the preparation of outdoor textiles.

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