Preparation method of super-amphiphobic moisture permeation protective fabric

Abstract

This invention provides a method for preparing a superhydrophobic and breathable protective fabric, solving the technical problems of complex or unstable preparation processes in existing superhydrophobic coatings. This invention uses tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17) as raw materials to prepare a superhydrophobic coating on the surface of a fiber fabric via a simple one-step method. The entire method is simple and economical, and because FAS-17, nano-silica, and the fiber surface are bonded by Si-O- chemical bonds, the stability of the coating is improved, resulting in a fabric with good stability.

Description

Technical Field

[0001] This invention belongs to the field of fabric protection technology, specifically relating to a method for preparing a super-dual moisture-permeable protective fabric. Background Technology

[0002] With societal development, people have increasingly higher demands for the comfort of medical or chemical protective clothing. Currently, commonly used medical protective clothing is primarily made of composite materials such as spunbond, meltblown, spunbond-meltblown-spunbond, spunlace, and flash-evaporated nonwoven fabrics, processed using composite molding processes such as coating, lamination, and finishing. Protective clothing typically requires high filtration efficiency, providing excellent barrier properties against water, blood, and chemical reagents, thus reducing breathability. Due to poor moisture permeability, wearers easily experience difficulty in wicking away sweat, leading to a stuffy and hot feeling, which can even affect their operation and cause accidents. Therefore, it is necessary to enhance the breathability of protective clothing. To solve the problem of "blocking" and "permeability" in protective clothing, researching waterproof and breathable protective fabrics is crucial. Developing super-double hydrophobic and breathable protective fabrics is of great significance for improving the protective effect of barrier-type protective clothing.

[0003] Superhydrophobic (hydrophobic and oleophobic) materials, due to their unique anti-wetting properties, have broad application prospects in self-cleaning, antifouling, anti-adhesion, and drag reduction, attracting the interest of many researchers. Inspired by natural plants and animals such as lotus leaves and water striders, researchers have conducted extensive research on the preparation of artificial superhydrophobic materials. Studies have shown that the superhydrophobicity or superoleophobicity of a material surface is mainly determined by the surface free energy and microstructure. Based on this theory, researchers have reported various artificial preparation methods for superhydrophobic surfaces, such as etching, electrospinning, and phase separation. Most of these methods have the problem of relatively cumbersome operation steps or the need for expensive and complex equipment. In contrast, the sol-gel method, with its simple equipment, low cost, and convenient operation, is widely used for the preparation of superhydrophobic surfaces. Sheen et al. used tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTES) as raw materials to prepare a surface with a surface energy as low as 1.38 mJ / m². 2Superhydrophobic coatings have been developed. Guo et al. prepared fluorinated silica sol using the sol-gel method, obtaining superhydrophobic coatings with contact angles of 161° and 156° for water and n-hexadecane, respectively. However, the coatings prepared by the above methods have poor stability and lack practicality. Durability is crucial for superhydrophobic materials, as they may lose their superhydrophobic properties after various damages, especially when used on fabric surfaces such as lab coats and gloves. In practical applications, they inevitably encounter harsh environmental conditions (such as strong acids and alkalis, organic solvent sputtering, or mechanical scratches). Therefore, superhydrophobic coatings require excellent physical and chemical stability during use. Li et al. prepared superhydrophobic zinc coatings on X90 pipeline steel substrates using a composite method combining deposition and chemical modification. Even after the superhydrophobic sample was exposed to air for six months, its water and glycerol CAs values ​​remained essentially unchanged, and the wettability of the coating showed almost no change, demonstrating good durability. Chen et al. prepared a durable superhydrophobic fabric using a gas-liquid sol-gel method by depositing silica with thiol (SiO2-SH) and grafting 1H,1H,2H,2H-heptafluorodecyl methacrylate (FMA) via a click reaction with thiol-alkene. This superhydrophobic fabric exhibits a surface tension as low as 27.5 mN / m. -1 The fabric exhibits excellent liquid resistance; importantly, it retains its superhydrophobic and adiaphragmatic properties even after repeated washing, abrasion, UV irradiation, and immersion in acid / alkali solutions. However, the aforementioned methods are complex to operate or require expensive equipment, resulting in high costs. Regarding moisture permeability, two approaches are currently used: one utilizes special porous structures, such as pores approximately one twenty-thousandth the size of a water droplet (average diameter about 100 μm), but 700 times larger than a water vapor molecule (average diameter about 0.4 nm). This method involves complex preparation processes, stringent production conditions, special film-forming equipment and raw materials, and extremely high technological requirements; the other utilizes fluorinated hydrophobic materials that also possess moisture permeability. However, this method suffers from stability issues in coating preparation.

[0004] It is evident that most methods for preparing superhydrophobic and amphoteric coatings cannot simultaneously achieve both simplicity and stable performance, thus limiting the practical application of superhydrophobic and amphoteric materials. Therefore, it is necessary to explore new preparation methods to simply construct stable, durable, and moisture-permeable superhydrophobic and amphoteric coatings. Based on this, it is essential to investigate a new method. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of complex or unstable preparation processes of existing superhydrophobic coatings, and to provide a method for preparing superhydrophobic and breathable protective fabrics.

[0006] To achieve the above objectives, the technical solution provided by this invention is:

[0007] A method for preparing a super-dual-permeable and moisture-wicking protective fabric, characterized by the following steps:

[0008] 1) Fiber surface pretreatment

[0009] The surface of the fabric fibers is hydroxylated to form a large number of active -OH groups;

[0010] 2) Preparation of ultra-dual moisture-permeable protective fabric

[0011] 2.1) Dry the fabric after the pretreatment in step 1);

[0012] 2.2) Add ammonia and ethanol to the dried fabric in step 2.1) and mix well; wherein, ammonia is a catalyst, and only the catalytic amount needs to be added, and ethanol is a hydrolysis solvent;

[0013] 2.3) Add tetraethyl orthosilicate to the mixed solution in step 2.2) and stir at room temperature for 2-3 hours to carry out the hydrolysis reaction. Then add 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and stir at room temperature to carry out the hydrolysis reaction.

[0014] 2.4) After the reaction is complete, clean the fabric and place it at 40-80℃ for at least 60 minutes to obtain a super-dual-layer moisture-permeable protective fabric. If the curing temperature is too high, the coating will crack or bubble due to the rapid evaporation of solvent; if the curing temperature is too low, the curing rate will be slow; if the curing time is too short, the curing will be incomplete; if the curing time is too long, aging may occur.

[0015] Furthermore, step 1) specifically involves:

[0016] 1.1) After ultrasonically cleaning the fabric with detergent powder for 0.5-1 hour, rinse repeatedly with deionized water until the detergent solution is neutral.

[0017] 1.2) Continue to wash the fabric obtained in 1.1) with agitation in anhydrous ethanol for 1-2 hours, then heat and boil it with a 3-5% NaOH solution for 0.5-1 hours, and wash it repeatedly with deionized water until the washing solution is neutral.

[0018] 1.3) Seal and store the treated fabric in anhydrous ethanol.

[0019] Further, in step 2), the volume ratio of tetraethyl orthosilicate to 1H,1H,2H,2H-perfluorodecyltrimethoxysilane is 4.5-7.5:0.9-1.5, preferably 7.5:0.9;

[0020] The amount of ethanol added is 20-25 times the total volume of tetraethyl orthosilicate and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane.

[0021] Furthermore, in step 2.4), the fabric is cleaned with deionized water and then placed in an oven for curing.

[0022] Furthermore, in step 2.3), magnetic stirring is employed.

[0023] Meanwhile, the present invention also provides a super-dual breathable and moisture-wicking protective fabric, which is special in that it is prepared by the above method.

[0024] Furthermore, the contact angle of water with the above-mentioned super-dual-permeable and moisture-repellent protective fabric is 160.5±0.8°; and the contact angle of vegetable oil is 154.8±2.6°.

[0025] In addition, a method for modifying fabrics is provided, which is special in that the above method is used to perform super-dual moisture-permeable modification.

[0026] And a protective product, which is special in that it is made of a super-dual moisture-permeable protective fabric prepared by the above method.

[0027] The principle of this invention

[0028] This invention uses tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17) as raw materials to prepare a superhydrophobic coating on the surface of fiber fabric in a simple one-step process. The key to this superhydrophobic and breathable protective fabric lies in the following: TEOS hydrolyzes with water under alkaline conditions to generate four Si-OH groups. The Si-OH groups condense to form nano-silica. The unreacted Si-OH groups on the surface of the silica particles are bonded to the fiber substrate surface through silicon-oxygen bonds. Simultaneously, when tetraethyl orthosilicate (TEOS) is not completely hydrolyzed, a solution of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17) is added as a hydrophobic modifier. At this point, the ethoxy groups in FAS-17, after hydrolysis, generate Si-OH functional groups, which readily combine with the highly reactive, unreacted Si-OH groups on the surface of the nano-silica particles. Because the fiber surface, nano-silica, and FAS-17 are covalently bonded, the stability of the coating is greatly improved. For details on the principle, please refer to [link to details]. Figure 1 The reaction equations are as follows (1)-(3):

[0029]

[0030] The advantages of this invention are:

[0031] 1. To address the shortcomings of existing protective fabric technologies, this invention uses TEOS and FAS-17 as raw materials. First, nano-silica is grafted onto the fabric surface using a simple Sol-gel method. Before the silica fully reacts, 1H,1H,2H,2H-triethoxyperfluorosilane (FAS-17) is used as a hydrophobic modifier, thus preparing a superhydrophobic coating with excellent stability and durability in one step. The entire method is simple and economical. Furthermore, because FAS-17, nano-silica, and the fiber surface are bonded by Si-O chemical bonds, the stability of the coating is improved, resulting in a fabric with good stability.

[0032] Durability tests were conducted on the prepared superhydrophobic and hydrophobic materials using physical and chemical methods. The results showed that the materials maintained excellent superhydrophobic and hydrophobic protective properties even after exposure to extreme environments, such as ultrasonic washing (at least 240 min), mechanical scratching, strong acids (concentrated sulfuric acid and concentrated nitric acid for at least 240 min), weak alkalis (concentrated ammonia for at least 240 min), and tetrahydrofuran immersion (at least 240 min). Compared with existing commonly used methods for preparing superhydrophobic materials, this method is not only simpler, but also produces a self-cleaning superhydrophobic, hydrophobic, waterproof, and breathable fabric with greater innovative value and application prospects.

[0033] 2. This invention, by controlling and optimizing the content of tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17), can control the rough structure and surface free energy of the coating, thereby enabling the customized preparation of a high-performance, ultra-dual-hydrophobic and breathable protective fabric. Furthermore, this method can be applied to different fabric surfaces, and the hydrostatic pressure resistance and moisture permeability of the fabric can be controlled according to the fabric pore size using the method of this invention.

[0034] 3. The coating prepared by this invention exhibits excellent superhydrophobic and amphoteric properties, with water and vegetable oil contact angles of (160.5±0.8° and 154.8±2.6°), respectively. Simultaneously, the coating withstands a hydrostatic pressure of up to 2187 Pa, has an air permeability of 34.843 mm / s, and a moisture permeability of 9498.23 g / m³. 2 ·day]. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the preparation of a self-cleaning, superhydrophobic protective fabric according to the present invention.

[0036] Figure 2 SEM images of self-cleaning superhydrophobic protective fabrics prepared under different TEOS volumes in Example 1 of this invention; a, a' are unmodified F0-SiO cotton fibers, b, b' are F0-SiO fibers. 0.9 -Si 1.5 The modified cotton fiber, c, c' is F 0.9 -Si 4.5The modified cotton fibers, d and d' are F. 0.9 -Si 7.5 The modified cotton fiber, e, e' is F0.9-Si10.5 modified cotton fiber;

[0037] Figure 3 The table shows the changes in the contact angle and surface free energy of the self-cleaning superhydrophobic protective fabric surface coating with different TEOS volumes prepared in Example 1 of the present invention, where (a) is the change in the coating contact angle with TEOS volume, and (b) is the change in the coating surface free energy with TEOS volume.

[0038] Figure 4 The XPS total spectrum and C1s fine spectrum of the self-cleaning superhydrophobic protective fabric prepared in Example 1 of this invention are shown, wherein (a) is the XPS total spectrum of FAS-17 superhydrophobic material at different volume concentrations, and (b) and (b') are the F... 0.9 -Si 7.5 C1s fine spectrum of superhydrophobic protective fabric, (b) represents etched 0s, (b') represents etched 10s;

[0039] Figure 5 The changes in the contact angle and surface free energy of the surface coating of the self-cleaning superhydrophobic protective fabric prepared with different FAS-17 volumes as a function of FAS-17 volume are shown in (a) for the change in the contact angle of the coating with the FAS-17 content and (b) for the change in the surface free energy of the coating with the FAS-17 content.

[0040] Figure 6 The diagram shows the changes in the wettability of the cotton fabric to water and oil before and after modification according to the present invention. In the diagram, a represents the situation where the surface of the cotton fabric before modification is wetted by purple water droplets and vegetable oil, and b represents the situation where the surface of the cotton fabric after modification is wetted by purple water droplets and vegetable oil.

[0041] Figure 7 The graph shows the relationship between the contact angle of water and vegetable oil and the soaking time in acid and alkali for the self-cleaning super hydrophobic protective fabric prepared in Example 1 of the present invention. In the graph, a is the change of WCA and b is the change of OCA.

[0042] Figure 8 The image shows the self-cleaning test pattern of the self-cleaning super hydrophobic protective fabric prepared in Example 1 of the present invention. In the image, a represents the surface of the cotton fabric before modification with contaminants, a' represents the state after rinsing the contaminants in a with water, and b represents the surface of the cotton fabric after modification with contaminants, b' represents the state after rinsing the contaminants in b with water.

[0043] Figure 9 For F 0.9 -Si 7.5 The relationship between surface contact angle and ultrasonic time;

[0044] Figure 10 Photographs showing the wettability of water and oil on the damaged surface; (a) before fiber damage, (b) after fiber damage, (c) water wetting at the damaged area, (d) vegetable oil wetting at the damaged area;

[0045] Figure 11 For F 0.9 -Si 7.5 The relationship between the contact angle of water and vegetable oil and the soaking time in strong acid and strong alkali: (a) is the change of WCA, (b) is the change of OCA;

[0046] Figure 12 For F 0.9 -Si 7.5 The relationship between surface contact angle and surface free energy and THF stirring time: (a) is the relationship between contact angle and THF stirring time; (b) is the relationship between surface free energy and THF stirring time. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0048] Materials prepared: Ethanol (99.0%), ammonia (28%), tetraethyl orthosilicate (TEOS, 99.0%), tetrahydrofuran, sodium hydroxide, concentrated sulfuric acid, and concentrated hydrochloric acid were purchased from China National Pharmaceutical Holding Chemical Reagent Co., Ltd.; 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (97%) was purchased from Adamas Co., Ltd. in Shanghai, China; rapeseed oil and fiber were sourced from commercial markets.

[0049] like Figure 1 As shown, a method for preparing a self-cleaning, super-hydrophobic protective fabric includes the following steps:

[0050] 1) Fiber surface pretreatment

[0051] 1.1) Use detergent powder to ultrasonically clean the fabric (cotton fibers) for 30 minutes (adjust the time appropriately within 0.5-1 hour depending on the cleanliness of the fabric), then repeatedly rinse with deionized water until the washing solution is neutral.

[0052] 1.2) Continue to wash the fabric obtained in 1.1) with agitation in anhydrous ethanol for 2 hours (adjustment can be made within 0.5-1 hour), then heat and boil it with 5% NaOH solution for 30 minutes (adjustment can be made within 0.5-1 hour), and wash it repeatedly with deionized water until the washing solution is neutral.

[0053] 1.3) Seal and store the treated fabric in anhydrous ethanol.

[0054] After treatment using this method, the fiber surface is hydroxylated, forming a large number of active -OH groups, which provides a basis for the subsequent stable bonding of silica and FAS-17.

[0055] 2) Preparation of ultra-dual breathable and moisture-permeable fabric

[0056] 2.1) After drying the pretreated fabric from step 1), place it in a reactor dish;

[0057] 2.2) Slowly add 4 mL of ammonia and 50 mL of ethanol to the dried fabric from step 2.1) and mix well.

[0058] 2.3) Add a certain volume of tetraethyl orthosilicate to the mixed solution in step 2.2), and carry out the hydrolysis reaction at room temperature with magnetic stirring for 2 hours (the complete hydrolysis reaction generally takes 3-4 hours, so this step can be adjusted within 2-3 hours, so that FAS-17 can be added before the reaction is complete). Then add a certain volume of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, and stir at room temperature for 1 hour to complete the hydrolysis reaction.

[0059] 2.4) Take out the fabric and rinse it with deionized water to remove unreacted raw materials on the surface. Place it in an oven at 60°C for 60 minutes to cure (depending on the fabric coating, the curing temperature and time can be adjusted within the range of 40-80°C for at least 60 minutes) to obtain a sample of super-dual breathable and moisture-wicking protective fabric.

[0060] For ease of representation, the sample is called F. X -Si X For example, F 0.9 -Si 7.5 F 0.9 This indicates that the volume of FAS-17 added was 0.9 mL, Si 7.5 This indicates that the volume of TEOS added was 7.5 mL; Table 1 below shows the EDS results of the superhydrophobic materials with different TEOS volumes:

[0061] Table 1

[0062]

[0063]

[0064] To verify the effect of the modified fabric, the following tests were conducted on the fabric:

[0065] Because the surface morphology of a material plays a crucial role in its wettability, different surface morphologies can be obtained by controlling the content of tetraethyl orthosilicate (TEOS). The microstructure of these different coatings can then be characterized using SEM. Figure 2As shown. For fibers without TEOS (i.e., unmodified), such as Figure 2 As shown in a and a', the fiber surface is relatively flat and smooth. With increasing TEOS content, the surface roughness gradually increases, such as... Figure 2 As can be seen from a to e', when TEOS is 1.5 ml, as TEOS hydrolyzes under the catalysis of ammonia, SiO2 nanoparticles are gradually formed on the fiber surface. However, at this time, the SiO2 nanoparticles cannot completely cover the fiber surface, such as... Figure 2 As shown in b', when the TEOS content increased to 7.5 ml, the fiber surface was completely covered by nano-SiO2 particles, and some nano-SiO2 particles agglomerated. Figure 2 (d'), with further increases in TEOS, when the TEOS content reached 10.5 ml, although sample F 0.9 -Si 10.5 The surface roughness further increases, but the nanoparticles on the fiber surface will agglomerate in large quantities, which may affect the uniformity and stability of the fiber surface. At the same time, the excessive amount of nano-SiO2 on the fiber surface, leading to an increase in Si-OH, will also reduce the hydrophobic and oleophobic properties of the material. EDS elemental analysis further proves that as the TEOS content increases, the F content on the fiber surface gradually decreases. When the TEOS content reaches 10.5 ml, the F content is only 2.37 (see Table 1 for details).

[0066] This invention also measured the contact angle and surface free energy of the surface coating of the superhydrophobic and breathable fabric prepared with different TEOS volumes in Example 1 as a function of TEOS volume. Figure 3 As shown in (a), when the FAS-17 content is 0.9 ml, the water contact angle increases with the increase of the added TEOS volume; when the TEOS content reaches 7.5 ml, the contact angles of water and vegetable oil are 160.5° and 154.8°, respectively, achieving a superhydrophobic effect; however, with the further increase of the TEOS content, reaching 10.5 ml, it can be seen from the figure that although FAS-17... 0.9 -Si 10.5 The sample had a water contact angle of 152.2°, but its contact angle with vegetable oil decreased significantly, reaching only 82.2°. Calculations of the surface free energy of modified fibers with different TEOS contents revealed that, for example... Figure 3As shown in (b), with the increase of TEOS, the surface free energy of the fiber first decreases and then increases. When the TEOS content is 7.5 ml, the surface free energy is the lowest at 0.936 mN / m. When the TEOS volume concentration reaches 10.5 ml, the surface free energy of the fiber increases significantly to 15.794 mN / m. This indicates that excessive TEOS hydrolyzes on the fiber surface to generate a large amount of SiO2. The Si–OH on the surface of SiO2 has strong hydrophilicity, which increases the surface free energy of the fiber, weakens the oleophobicity, and loses the super-dual-hydrophobic effect.

[0067] The surface chemical composition of the coating is crucial to its wettability, such as... Figure 4 As shown, XPS (X-ray photoelectron spectroscopy) was performed on the fabric obtained in Example 1 to further analyze the surface chemical composition of fibers with different FAS-17 contents. The XPS total spectrum ( Figure 4 As can be clearly seen in (a), compared with the blank fiber, the sample treated with FAS-17 and TEOS showed a distinct Fls peak at 687.8 eV, and distinct Si2p and Si2s peaks at 102.8 eV and 152.8 eV, respectively. Figure 4 In (1-5) of the a group, the F1s peak gradually increases with the increase of FAS-17 content. To obtain more detailed information about the material surface elements, the XPS high-resolution spectral curves of C1s were studied, as shown in Figure 1-5. Figure 4 As shown in b and b'. The results show that at 284.8 eV, 285.7 eV, 290.7 eV and 292.2 eV, corresponding to -CC, -CO-R, -CF2 and -CF3 respectively, the binding form of C on the fiber surface mainly exists in the form of -CF2 and -CF3. By comparing the ratio of the peak areas of -CF and CO in the coating at 0 s and 10 s etching, when etching is 0 s, (-CF)peak area / (CO)peak area = 2.01, and when etching is 10 s, (-CF)peak area / (CO)peak area = 0.999. It can be inferred that during the modification process, low surface energy fluorides mainly cover the surface of the fiber and nano silica, thereby further reducing the surface free energy of the coating and achieving superhydrophobic properties.

[0068] Meanwhile, following the above preparation method, this invention measured the changes in the surface coating contact angle and surface free energy of self-cleaning superhydrophobic protective fabrics prepared with the same TEOS volume (7.5 ml) and different FAS-17 volumes, as a function of FAS-17 volume. Figure 5In (a), it can be seen that as the FAS-17 content increases, the contact angle between water and vegetable oil first increases and then decreases. When the FAS-17 content reaches 0.9 mL, the contact angles between water and vegetable oil reach 160.5° and 154.8°, respectively. With further increases in the FAS-17 volume, the performance of the superhydrophobic material gradually decreases. When the FAS-17 content reaches 2.0 mL, the contact angle between water and vegetable oil decreases significantly. This is achieved through calculations of the surface free energy of different samples (…). Figure 5 (b) When FAS-17 reaches 2.0 mL, the surface free energy of the sample increases sharply. This is because when an excess of FAS-17 is added, the excess FAS-17 cannot bond with Si-OH on the surface of nano silica. Instead, intramolecular condensation of FAS-17 occurs, and it adheres to the fiber surface in the form of wet gel, resulting in an increase in its surface free energy and a decrease in its superhydrophobic properties. It can be seen that low surface energy substances have a significant impact on the wettability of materials.

[0069] like Figure 6 As shown, the fabric obtained in Example 1 was subjected to a wettability test. Figure 6 It is evident that cotton fibers, before modification, readily become wetted, while from... Figure 6 As can be seen from b, after the cotton fibers are treated, water and oil do not soak in the fabric but instead agglomerate into a sphere. This indicates that the super-dual-repellent protective fabric prepared by this invention can exhibit excellent liquid repellency to water and vegetable oil, and therefore has a good protective effect against liquid harmful substances.

[0070] like Figure 7 As shown, the fabric obtained in Example 1 was subjected to a chemical stability test. To explore the application of the superhydrophobic protective fabric in the field of special protection, the chemical stability of the fabric was further tested by immersing the entire superhydrophobic material in strong concentrated HCl, concentrated ammonia, and saturated sodium hydroxide solutions. Figure 7 As can be seen from a, after soaking in concentrated hydrochloric acid and concentrated ammonia for 240 min, the WCA of the coating is 150.2° and 150.3°, respectively, and the fabric still maintains high amphotericity, indicating that the coating prepared by this method has excellent stability under strong acid and weak alkali conditions.

[0071] like Figure 8 As shown, a self-cleaning test was conducted on the fabric obtained in Example 1. Fine sand was used as a contaminant, and the contaminant was sprinkled on the surface of the unmodified cotton fabric (blank sample) and the super-hydrophobic protective fabric (obtained in Example 1). When subjected to water flow, the fine sand on the surface of the blank sample mixed with water and adhered to the fiber surface. Figure 8 (a and a'), while after being impacted by water flow, the super hydrophobic protective fabric causes water droplets to envelop sand particles, forming water balls that slide off the fibers and carry away the dirt, ultimately creating a clean surface. Figure 8The results of b and b' indicate that the prepared superhydrophobic coating has excellent self-cleaning properties.

[0072] In addition, the fabrics obtained in Example 1 were tested for water resistance, moisture permeability, and air permeability. Table 2 shows that the unmodified ordinary fiber cotton fabric (Item 1) has a hydrostatic pressure of 0 Pa and no water resistance. However, the modified fiber cotton fabric (Item 2) obtained using the method of this invention has a hydrostatic pressure of 2.187 kPa, which exceeds the 1.67 kPa requirement of GB19082-2009 "Technical Requirements for Medical Disposable Protective Clothing," demonstrating superior water resistance and waterproofing performance. Furthermore, after modification, its moisture permeability reaches as high as 9498.23 g / m³. 2 The day value is far greater than the 2500g / m³ specified in GB19082-2009. 2 • Day requirements. Simultaneously, the breathability increased from 21.292 mm / s to 34.843 mm / s after modification, indicating that the fabric, while possessing a certain degree of waterproofing, also exhibits excellent moisture permeability and breathability, greatly improving the comfort of protective clothing. It is expected to be used as a self-cleaning, waterproof, and breathable protective clothing fabric. While the hydrostatic pressure and moisture permeability of items 3 and 4, modified using existing methods, changed, overall, their performance was not as superior as that of item 2.

[0073] Table 2 Comparison of Water Resistance, Moisture Permeability, and Breathability of Modified Fabric with Blank Fiber Cotton Fabric

[0074]

[0075] To achieve reusability, the fibers need to possess excellent wash resistance. Considering the practical applications of superhydrophobic materials in external environments, their mechanical stability is a crucial factor determining the material's lifespan. In this invention, the research team also employed ultrasonic cleaning and physical damage to test the durability of the superhydrophobic coating. After washing the sample F0.9-Si7.5 in an ultrasonic cleaner (using water as the solvent) for a period of time, its contact angles with water and vegetable oil were as follows: Figure 9 As shown in the figure, it can be seen that with the increase of washing time, after 240 minutes of ultrasonic washing, the contact angles of water and vegetable oil did not change significantly and remained above 150°, indicating that the superhydrophobic coating has excellent stability under ultrasonic washing conditions.

[0076] To test the superhydrophobic and amphoteric properties of the coating after physical damage, the sample was placed on a glass slide and repeatedly scratched with a scribe until it broke, thus performing a physical damage test. Figure 10As can be seen, the superhydrophobic coating still maintains good anti-wetting properties against water and vegetable oil after physical damage, further indicating that the coating retains its superhydrophobic properties even under extreme mechanical damage. Therefore, when used as a protective material, it still possesses a certain degree of protection against accidental damage. In summary, the prepared superhydrophobic material exhibits good mechanical stability.

[0077] To explore the application capabilities of superhydrophobic and hydrophobic fabrics in the field of special protection, and to further test the chemical stability of the coating, the entire superhydrophobic and hydrophobic material was immersed in concentrated HCl, concentrated ammonia, and saturated sodium hydroxide solutions. Figure 11 As shown in Figure a, after immersion in concentrated hydrochloric acid and concentrated ammonia for 240 min, the WCA of the coating was 150.2° and 150.3°, respectively, and the OCA was 144.9° and 144.2°, respectively, indicating that the fabric still maintained high hydrophobicity. However, after immersion in saturated sodium hydroxide solution for 120 min, both the WCA and OCA of the coating decreased sharply. When immersed for 240 min, the coating even reached superhydrophilicity. This may be because sodium hydroxide can react with Si-O-Si bonds, destroying the nano-silica and fluorides grafted on the fiber surface, leading to a decrease in hydrophobicity. At the same time, after the reaction of sodium hydroxide with silica particles, a large number of hydroxyl groups remain on the fiber surface, further increasing the hydrophilicity of the fiber surface.

[0078] The solvent resistance of the sample was determined by magnetic stirring in tetrahydrofuran (THF) solvent. Figure 12 As can be seen from Figure a, with the increase of stirring time, the contact angle of water did not change significantly, reaching 153.6° at 240 min, maintaining superhydrophobicity; the contact angle of vegetable oil decreased, reaching 150.5° at 40 min, indicating that the sample still maintained superhydrophobicity within 40 min of stirring, and the contact angle of vegetable oil was 141.4° at 240 min. Figure 10 As can be seen from b, in THF, the surface energy of the coating does not change much with the increase of stirring time, indicating that the coating is grafted onto the fiber surface in the form of chemical bonds and has excellent solvent resistance.

[0079] In summary, this invention successfully prepared a stable superhydrophobic coating on the fiber surface using a simple sol-gel method (balancing simplicity and stability). The invention's objectives were met when the volume ratio of tetraethyl orthosilicate to 1H,1H,2H,2H-perfluorodecyltrimethoxysilane was 4.5-7.5:0.9-1.5. Particularly at 7.5:0.9, the coating exhibited the largest contact angle, with water and vegetable oil contact angles of 160.5±0.8° and 154.8±2.6°, respectively, indicating optimal superhydrophobic properties. During preparation, the nanofiber surface, SiO2, and fluorides were all covalently bonded to the fiber surface, contributing to the excellent stability of the superhydrophobic coating. The samples retained good superhydrophobic properties even after immersion in strong acids and alkalis, stirring in THF, and mechanical friction damage, demonstrating the excellent mechanical and chemical stability of the prepared superhydrophobic material. It is expected to have broad application prospects in the field of breathable personal protective equipment.

[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A method of making a superomniphobic, moisture-permeable, protective fabric, characterized in that, Includes the following steps: 1) Fiber surface pretreatment The fabric fiber surface is hydroxylated to form active -OH groups, specifically: 1.1) After ultrasonically cleaning the fabric with detergent powder for 0.5-1 h, rinse it repeatedly with deionized water until the washing solution is neutral. 1.2) Continue to wash the fabric obtained in 1.1) with agitation in anhydrous ethanol for 1-2 h, then heat and boil it with a 3-5% NaOH solution for 0.5-1 h, and wash it repeatedly with deionized water until the washing solution is neutral. 1.3) Seal and store the treated fabric in anhydrous ethanol; 2) Preparation of ultra-dual moisture-permeable protective fabric 2.1) Dry the fabric after the pretreatment in step 1); 2.2) Add ammonia and ethanol to the dried fabric from step 2.1) in sequence, and mix well; 2.3) To the mixed solution of step 2.2), first add tetraethyl orthosilicate, stir at room temperature to carry out hydrolysis reaction for 2-3 hours, then add 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, stir at room temperature to carry out hydrolysis reaction; The volume ratio of tetraethyl orthosilicate to 1H,1H,2H,2H-perfluorodecyltrimethoxysilane is 4.5-7.5:0.9-1.

5. The amount of ethanol added is 20-25 times the total volume of tetraethyl orthosilicate and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane. 2.4) After the reaction is complete, clean the fabric and cure it at 40-80℃ for at least 60 min to obtain a super-dual breathable and moisture-wicking protective fabric, in which FAS-17, nano silica and fiber surface are combined by Si-O- chemical bonds.

2. The preparation method according to claim 1, characterized in that: In step 2), the volume ratio of tetraethyl orthosilicate to 1H,1H,2H,2H-perfluorodecyltrimethoxysilane is 7.5:0.

9.

3. The preparation method according to claim 1, characterized in that: In step 2.4), the fabric is cleaned with deionized water and then placed in an oven for curing.

4. The preparation method according to claim 1, characterized in that: In step 2.3), magnetic stirring is used.

5. A superomniphobic, moisture permeable, protective fabric, characterized in that: Prepared using the method described in any one of claims 1-4.

6. A protective article characterized by: The super-dual moisture-permeable protective fabric is prepared using the method described in any one of claims 1-4.

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