An ultrahydrophobic fabric with self-cleaning and oil-water separation functions and a preparation method and application thereof

Abstract

The application discloses a kind of super-hydrophobic fabric with self-cleaning and oil-water separation function and its preparation method and application, belong to functional textile technical field, including the following steps: after fabric base material is soaked in eutectic solvent and is carried out surface roughening etching pretreatment, in long-chain organosilane colloidal coating solution Impregnation reaction, after reaction, washing, drying, the super-hydrophobic fabric is obtained.The preparation process provided by the application is easy to obtain raw materials, simple equipment, easy to mass production.In addition, the super-hydrophobic fabric prepared by the application can maintain stable self-cleaning and oil-water separation performance, and has inherent advantages such as flexibility, air permeability and controllable porosity, and can be widely used in self-cleaning surface, oil-water separation filter material, outdoor antifouling material and other fields, with wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of functional textile technology, and in particular relates to a superhydrophobic fabric with self-cleaning and oil-water separation functions, its preparation method and application. Background Technology

[0002] With the continued deepening of global industrialization and the increasing awareness of environmental protection, the treatment of oily wastewater pollution and the functionalization and low-maintenance requirements of textiles have become important issues in the fields of environmental science and textile engineering. In recent years, superhydrophobic materials based on textile substrates have attracted widespread attention due to their advantages such as porous interconnected structure, good flexibility, strong designability, and low raw material cost. They are considered ideal carriers for developing efficient, large-scale oil-water separation and self-cleaning products. Superhydrophobic materials based on textile substrates have shown broad prospects in outdoor protection, marine antifouling, biomedical applications, and flexible filtration devices.

[0003] The superhydrophobic properties of fabrics typically rely on the synergistic effect of micro- to nano-level roughened surface structures and low surface energy materials. Currently, superhydrophobic finishing methods for textiles mainly include sol-gel methods, electrospinning, chemical vapor deposition, surface etching, and coating modification. However, these methods still have significant limitations in practical applications: for example, complex processes, reliance on expensive equipment, use of toxic or recalcitrant chemicals, weak bonding between finishing agents and fibers, and insufficient durability (abrasion resistance, wash resistance, and chemical corrosion resistance). In particular, many technical approaches struggle to construct robust and uniform superhydrophobic structures on soft and porous fabric surfaces, often sacrificing the fabric's original breathability, softness, and other wearing comfort while imparting hydrophobic functionality. Furthermore, superhydrophobic fabrics prepared using existing technologies often face challenges such as limited functionality, decreased recyclability, and difficulty in simultaneously achieving efficient oil-water separation and long-lasting self-cleaning capabilities.

[0004] Therefore, how to provide a simple, low-cost, environmentally friendly superhydrophobic functionalization method applicable to a variety of textile materials to prepare superhydrophobic fabrics with excellent self-cleaning properties, efficient oil-water separation capabilities, and good durability to meet the growing market demand is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a superhydrophobic fabric with self-cleaning and oil-water separation functions, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions includes the following steps: After the fabric substrate is immersed in a eutectic solvent for surface rough etching pretreatment, it is immersed in a long-chain organosilane colloidal coating solution to grow alkyl chain nanoparticles on the fabric surface. After the reaction is completed, the fabric is cleaned and dried to obtain the superhydrophobic fabric.

[0007] Beneficial Effects: This invention utilizes a green, eutectic solvent. Through its unique hydrogen bond network and the synergistic effect of mild acidity, it can efficiently etch the surface of fiber materials at room temperature and pressure, rapidly constructing a uniform and dense micro-nano-scale rough structure. This process completely abandons traditional strong acid, strong alkali, or high-energy-consuming physical etching methods, significantly shortening processing time and achieving zero pollution emissions from the source, fully aligning with the concept of green manufacturing. Furthermore, this invention innovatively introduces a low-temperature mechanical mixing reaction between long-chain organosilanes and water. This process can be carried out stably in the room temperature to low-temperature range, requiring no heating or high-pressure conditions, resulting in extremely low energy consumption and high safety. The entire coating preparation process is simple, efficient, and reproducible, with low raw material costs. It can be directly adapted to existing industrial coating production lines, providing a green, large-scale solution for the textile fiber substrate field that combines superhydrophobic properties, long-term durability, and economic feasibility.

[0008] Preferably, the fabric base material is one or a blend of several of the following: cotton, linen, cellulose fiber, and synthetic fiber. More preferably, it is one of pure cotton fabric, polyester fabric, or polyester-cotton fabric (T / C 70 / 30).

[0009] More preferably, before the surface roughening etching pretreatment, the fabric substrate material is cleaned with water and ethanol and then dried at 80°C for 2 hours to remove dust and adhering substances.

[0010] Preferably, the hydrogen bond acceptor in the eutectic solvent is choline chloride, and the hydrogen bond donor is oxalic acid.

[0011] The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1.

[0012] More preferably, the method for preparing the eutectic solvent includes the following steps: The hydrogen bond acceptor and hydrogen bond donor were magnetically stirred at 100°C for 1 h to obtain the eutectic solvent.

[0013] More preferably, the bath ratio of the fabric substrate material to the eutectic solvent is 1:100.

[0014] Preferably, the surface roughening etching pretreatment is performed at a temperature of 60°C for 2 hours.

[0015] More preferably, the surface roughening etching pretreatment further includes drying at 80°C for 2 hours.

[0016] Preferably, the impregnation reaction is carried out at a temperature of 20-35°C for 12 hours.

[0017] More preferably, during the impregnation reaction, the volume ratio of the long-chain organosilane colloidal coating solution to the fabric area is 20 mL: (4 cm²) 2 ~10cm 2 ).

[0018] The preparation method of the long-chain organosilane colloidal coating solution includes the following steps: After mixing the long-chain organosilane with water, the mixture is vortexed in an open container for 20 seconds, then ultrasonically treated under sealed conditions for 20 seconds, vortexed for 20 seconds, and allowed to stand before adding n-hexane and mixing evenly to obtain the long-chain organosilane colloidal coating solution.

[0019] Beneficial Effects: This invention promotes the hydrolysis and polycondensation of long-chain organosilanes through mechanical shearing, generating highly reactive oligomers in situ, ensuring a strong chemical bond with the fiber surface. Furthermore, this invention requires only a trace amount of n-hexane as a diluent to precisely formulate the aforementioned active components (highly reactive oligomers) into a hydrophobic coating solution with moderate viscosity and excellent wettability. This coating solution exhibits outstanding stability, and the n-hexane is easily volatilized and recovered, significantly reducing the risk of solvent residue and recycling costs.

[0020] Preferably, the long-chain organosilane includes one or more of octadecyltrichlorosilane, hexadecyltrichlorosilane, and dodecyltrichlorosilane.

[0021] Preferably, the settling conditions are that the reaction vessel is covered but not sealed, and the settling time is 4 hours; Preferably, the volume ratio of the long-chain organosilane to water is 1:0.02.

[0022] The volume ratio of n-hexane to the solution obtained after standing is 20:1.

[0023] Beneficial Effects: The long-chain alkylsilane in this invention is mainly composed of hydrophilic chloride ions, silanol groups, and hydrophobic alkanes. When it comes into contact with water and is mechanically dispersed, the long-chain organosilane loses chloride ions and combines with hydroxyl groups in the water to form -Si-OH bonds, thereby constructing a spherical structure with the hydrophilic end facing the water droplet and the hydrophobic chain facing outward, forming a particulate siloxane polymer. During continuous hydrolysis and condensation reactions, a relatively stable structure is formed between the nanospheres through Si-O bonds. As the number of Si-O bonds increases, the nanoparticles gradually transform from nanoparticles into head-to-head linear fibers, encountering energy barriers during aggregation. Subsequently, the linear fibers further aggregate and eventually form microparticles. Through processes such as dip coating or spraying, sufficient microparticles can be attached to the surface of the fabric sample to form a uniform and dense hydrophobic layer. The structure of the alkyl chain nanoparticles in the hydrophobic layer is as follows... Figure 1 The structure shown is that of medium- to long-chain silane colloids.

[0024] A superhydrophobic fabric with self-cleaning and oil-water separation functions prepared by the preparation method described above.

[0025] Application of a superhydrophobic fabric with self-cleaning and oil-water separation functions in self-cleaning surfaces, oil-water separation filter materials, or outdoor antifouling materials.

[0026] More preferably, the self-cleaning functional surface is used in fields such as flexible wearables, industrial protection, and medical supplies, and achieves self-cleaning of the surface by resisting and effectively removing pollutants such as impurities and dust. More preferably, the oil-water separation filter material is used in fields such as industrial oily wastewater treatment, water pollution recovery, and oily waste treatment in the catering industry. Through its superhydrophobic / superhydrophilic surface properties, it allows the oil phase to pass quickly through the porous structure of the fabric, while the water phase is blocked, thereby achieving efficient separation. More preferably, the outdoor antifouling material is used in outdoor clothing, building exterior walls, tents and other fields. Through its stable superhydrophobicity and excellent breathability, it endows the material with efficient waterproof and antifouling functions in complex outdoor environments.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects: This invention employs a simple, environmentally friendly, low-cost, and highly efficient two-step "etching-modification" process to prepare flexible, breathable, and superhydrophobic fabrics. These fabrics are suitable for functional flexible materials with different pore sizes, specifications, and dimensions, and the entire process does not involve any toxic or polluting solvents. Furthermore, the superhydrophobic fabrics prepared by this invention exhibit excellent superhydrophobic and oil-water separation properties, with a water contact angle greater than 160.9° and an oil-water separation efficiency exceeding 99.3%. They are recyclable, exhibit stable performance, and maintain high hydrophobicity and oil-water separation efficiency even after repeated abrasion tests. Moreover, the preparation process of this invention uses readily available raw materials and simple equipment. Only a green, low-melting-point solvent for surface etching is prepared by mixing choline chloride and oxalic acid, and a long-chain organosilane colloidal coating solution is prepared by hydrolyzing and condensing a long-chain alkylsilane containing chloride ions and silanol groups with a small amount of water. Functionalization can be achieved by treating the fabric substrate material using conventional processes such as impregnation and coating, making it easy for large-scale production. Furthermore, the superhydrophobic fabric prepared by this invention maintains stable self-cleaning and oil-water separation properties while also possessing the inherent advantages of fabrics such as flexibility, breathability, and controllable pores. It can be widely used in fields such as self-cleaning surfaces, oil-water separation filter materials, and outdoor antifouling materials, and has broad application prospects. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the preparation process of the superhydrophobic fabric in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram illustrating the hydrophobic principle of the long-chain organosilane colloidal superhydrophobic coating in this invention. Figure 3 Scanning electron microscope (SEM) images (a)-(c) of the polyester fabric raw material in Example 1 of the present invention; scanning electron microscope (SEM) images (d)-(f) of the pretreated polyester fabric obtained in step (1) of Example 1; scanning electron microscope (SEM) images (g)-(i) of the superhydrophobic polyester fabric obtained in step (3) of Example 1; elemental energy dispersive spectroscopy (EDS) analysis diagrams (j)-(l) of the superhydrophobic polyester fabric obtained in step (3) of Example 1. Figure 4 The superhydrophobic pure cotton fabric obtained in Example 5 of this invention floats in water at different times; Figure 5 This is the self-cleaning state of the superhydrophobic pure cotton fabric obtained in Example 3 of the present invention, where the soy sauce on the surface is washed away by water droplets; The left image shows a superhydrophobic pure cotton fabric with soy sauce dripped onto it, while the right image shows the superhydrophobic pure cotton fabric after the soy sauce has been washed away by water droplets. Figure 6This is the self-cleaning state of the superhydrophobic pure cotton fabric surface powder obtained in Example 3 of the present invention, where water droplets carry away the powder. The left image shows powder added to a superhydrophobic pure cotton fabric, while the right image shows the powder on the surface of the superhydrophobic pure cotton fabric being carried away by water droplets. Figure 7 The state of different stain droplets remaining on the surface of the superhydrophobic pure cotton fabric obtained in Example 3 of the present invention; Figure 8 Comparison images of the pure cotton fabric raw material (a) and the superhydrophobic pure cotton fabric (b) obtained in Example 3 of the present invention before and after immersion in methylene blue trihydrate dyeing solution; Figure 9 The diagram shows the durability wear test of the present invention (a) and the contact angle histogram of the superhydrophobic fabric in Example 4 under different friction cycles (b). Figure 10 The superhydrophobic pure cotton fabric obtained in Example 3 of this invention is used as a filter material to achieve oil-water separation of dichloromethane / water components in an oil-water mixture; Figure 11 The oil-water separation efficiency of the superhydrophobic pure cotton fabric obtained in Example 3 of the present invention for various oil-water mixtures (a) and cyclohexane / water in 10 separation cycles (b); Figure 12 Images showing dynamic measurements of the superhydrophobic pure cotton fabric obtained in Example 5 of this invention with water droplets under low adhesion (a) and high adhesion (b) conditions; Figure 13 This is a comparison of the state of the unmodified fabric of the present invention and the superhydrophobic fabrics obtained in Examples 1-5 after contact with water; Figure 14 These are actual photographs and bar charts of the contact angles of the superhydrophobic fabrics obtained in Examples 1-5 of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels; Among them, the polyester fabric has a weight of 170 g / m². 2Provided by Dongguan Huwei Fabric Textile Factory; Polyester-cotton (T / C 70 / 30) fabric weight is 180 g / m². 2 Provided by Dongguan Huwei Fabric Textile Factory; The weight of pure cotton fabric is 165 g / m². 2 Provided by Dongguan Huwei Fabric Textile Factory; Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0032] Example 1 A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, such as... Figure 1 As shown, it includes the following steps: (1) Surface rough etching of polyester fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester fabric (DPF) with rough etching.

[0033] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of octadecyltrichlorosilane (OTS). The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0034] (3) Preparation of superhydrophobic polyester fabric: The pretreated polyester fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic polyester fabric (ODPF).

[0035] Example 2 A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, differing from Example 1 in that the polyester fabric in step (1) is replaced with a polyester-cotton (T / C 70 / 30) fabric, specifically including the following steps: (1) Surface rough etching of polyester-cotton fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The cotton (T / C 70 / 30) fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OA DES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester-cotton fabric with a rough etched surface.

[0036] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0037] (3) Preparation of superhydrophobic polyester-cotton fabric: The pretreated polyester-cotton fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the polyester-cotton fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic polyester-cotton fabric.

[0038] Figure 4 The superhydrophobic polyester-cotton fabric obtained in Example 2 of this invention floats in water at different times, as shown by... Figure 4 As can be seen, the superhydrophobic polyester-cotton fabric still floats on the water surface after 60 days, demonstrating its excellent superhydrophobic properties.

[0039] Example 3 A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, differing from Example 1 in that the polyester fabric in step (1) is replaced with pure cotton fabric, specifically including the following steps: (1) Surface rough etching of pure cotton fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The pure cotton fabric (2 cm × 4 cm) was cleaned with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated pure cotton fabric with a rough etched surface.

[0040] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0041] (3) Preparation of superhydrophobic pure cotton fabric: The pretreated pure cotton fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the pure cotton fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic pure cotton fabric.

[0042] Example 4 A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, differing from Example 3 in that octadecyltrichlorosilane in step (3) is replaced with hexadecyltrichlorosilane, specifically including the following steps: (1) Surface rough etching of pure cotton fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The pure cotton fabric (2 cm × 4 cm) was cleaned with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated pure cotton fabric with rough etching.

[0043] (2) Preparation of hexadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of hexadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the hexadecyltrichlorosilane colloidal coating solution.

[0044] (3) Preparation of superhydrophobic pure cotton fabric: The pretreated pure cotton fabric obtained in step (1) was immersed in 20 mL of hexadecyltrichlorosilane colloidal coating solution for 12 h at room temperature to grow alkyl chain nanoparticles on the surface of the pure cotton fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic pure cotton fabric.

[0045] Example 5 A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, differing from Example 3 in that octadecyltrichlorosilane in step (3) is replaced with dodecyltrichlorosilane, specifically including the following steps: (1) Surface rough etching of pure cotton fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The pure cotton fabric (2 cm × 4 cm) was cleaned with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated pure cotton fabric with rough etching.

[0046] (2) Preparation of dodecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of dodecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, and then sonicated for 20 s under completely sealed conditions. The mixture was then vortexed for another 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the dodecyltrichlorosilane colloidal coating solution.

[0047] (3) Preparation of superhydrophobic pure cotton fabric: The pretreated pure cotton fabric obtained in step (1) was immersed in 20 mL of dodecyltrichlorosilane colloidal coating solution for 12 h at room temperature to grow alkyl chain nanoparticles on the surface of the pure cotton fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic pure cotton fabric.

[0048] Comparative Example 1 A method for preparing a hydrophobic fabric, differing from Example 1 in that the amount of octadecyltrichlorosilane added in step (2) is 0.5 mL, specifically including the following steps: (1) Surface rough etching of polyester fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester fabric with a rough etched surface.

[0049] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 0.5 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0050] (3) Preparation of hydrophobic polyester fabric: The pretreated polyester fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain hydrophobic polyester fabric.

[0051] Comparative Example 2 A method for preparing a hydrophobic fabric, which differs from Comparative Example 1 in that the immersion time in step (3) is 24 hours, specifically including the following steps: (1) Surface rough etching of polyester fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester fabric with a rough etched surface.

[0052] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 0.5 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0053] (3) Preparation of hydrophobic polyester fabric: The pretreated polyester fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 24 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain hydrophobic polyester fabric.

[0054] Comparative Example 3 A method for preparing a hydrophobic fabric, which differs from Example 1 in that it does not include step (1), but specifically includes the following steps: (1) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 0.5 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0055] (2) Preparation of hydrophobic polyester fabric: The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80 °C for 2 h and then immersed in octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain hydrophobic polyester fabric.

[0056] Comparative Example 4 A method for preparing a hydrophobic fabric, which differs from Example 4 in that the reaction container in step (2) is placed for 2 hours under a capped but not sealed condition, specifically including the following steps: (1) Surface rough etching of pure cotton fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The pure cotton fabric (2 cm × 4 cm) was cleaned with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated pure cotton fabric with rough etching.

[0057] (2) Preparation of hexadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of hexadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, after the reaction vessel was covered but not sealed, 20 mL of n-hexane was added to the first solution and shaken to prepare the hexadecyltrichlorosilane colloidal coating solution.

[0058] (3) Preparation of hydrophobic pure cotton fabric: The pretreated pure cotton fabric obtained in step (1) was immersed in 20 mL of hexadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the pure cotton fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain hydrophobic pure cotton fabric.

[0059] Comparative Example 5 A method for preparing a hydrophobic fabric, which differs from Comparative Example 1 in that the immersion time in step (3) is 6 hours, specifically including the following steps: (1) Surface rough etching of polyester fabric: 70g choline chloride and 45g oxalic acid were magnetically stirred and mixed at 100℃ for 1h. After complete mixing and dissolution, a ChCl / OA DES solution was obtained. The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2h. After that, it was immersed in the ChCl / OADES solution at 60℃ with a bath ratio of 1:100 for 2h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester fabric with a rough etched surface.

[0060] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 0.5 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0061] (3) Preparation of hydrophobic polyester fabric: The pretreated polyester fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 6 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain hydrophobic polyester fabric.

[0062] Comparative Example 6 A method for preparing a hydrophobic fabric, which differs from Example 1 in that the type of eutectic solvent in step (1) is changed, specifically including the following steps: (1) Surface rough etching of polyester fabric: 70g of choline chloride and 62g of ethylene glycol were magnetically stirred and mixed at 100℃ for 1 h. After complete mixing and dissolution, a DES solution was obtained. The polyester fabric (2 cm × 4 cm) was washed with deionized water and ethanol to remove dust and adhering substances. It was then dried at 80℃ for 2 h. After that, it was immersed in the DES solution at 60℃ with a bath ratio of 1:100 for 2 h. After rinsing with deionized water for 30 min, it was dried at 80℃ to obtain the pretreated polyester fabric with a rough etched surface.

[0063] (2) Preparation of octadecyltrichlorosilane colloidal coating solution: 20 μL of deionized water was added to 1.0 mL of octadecyltrichlorosilane. The mixture was vortexed for 20 s with the reaction vessel open, then sonicated for 20 s under completely sealed conditions, and then vortexed for 20 s to obtain the first solution. Subsequently, the mixture was placed in the reaction vessel with the lid on but not sealed for 4 h. Then, 20 mL of n-hexane was added to the first solution and shaken to prepare the octadecyltrichlorosilane colloidal coating solution.

[0064] (3) Preparation of superhydrophobic polyester fabric: The pretreated polyester fabric obtained in step (1) was immersed in 20 mL of octadecyltrichlorosilane colloidal coating solution at room temperature for 12 h to grow alkyl chain nanoparticles on the surface of the polyester fabric. Finally, it was washed with n-hexane 3 times and dried naturally to obtain superhydrophobic polyester fabric.

[0065] Technical effects: 1. Hydrophobic principle like Figure 2 As shown, the formation mechanism of the long-chain organosilane colloidal coating in this invention is as follows: When the long-chain alkylsilane comes into contact with water and is mechanically dispersed, it loses chloride ions and combines with hydroxyl groups in the water to form -Si-OH, thereby constructing a polymer siloxane particle with a spherical structure having the hydrophilic end facing the water droplet and the hydrophobic chain facing outward. During continuous hydrolysis and condensation reactions, a relatively stable structure is formed between the nanospheres through Si-O bonds. As the number of Si-O bonds increases, the nanoparticles gradually transform from nanoparticles into head-to-head linear fibers, encountering energy barriers during aggregation. Subsequently, the linear fibers further aggregate and eventually form microparticles. Through processes such as impregnation coating, sufficient microparticles adhere to the surface of the fabric sample, forming a uniform and dense hydrophobic layer.

[0066] 2. Characterization of microstructure and elemental composition The microstructure and elemental content and distribution of the original unmodified fabric, the surface-etched pretreated fabric, and the final superhydrophobic fabric were characterized by scanning electron microscopy (SEM, SEM3200, QuantumCTek Ltd., China) and energy dispersive X-ray spectroscopy (EDS).

[0067] Figure 3The images show: Scanning electron microscope (SEM) images of the unmodified fabric from Example 1 (ac); Scanning electron microscope (SEM) image of the fabric after surface etching from Example 1 (df); Scanning electron microscope (SEM) image of the fabric after hydrophobic coating modification from Example 1 (gi); and elemental energy dispersive spectroscopy (EDS) analysis of the fabric after hydrophobic coating modification from Example 1 (jl). It can be seen that the surface of the polyester fabric raw material is relatively smooth. After pretreatment, the fabric surface is clearly etched, with fine grooves and increased surface roughness. Furthermore, the surface of the polyester fabric obtained in Example 1 is covered with long-chain organosilane colloids, further increasing surface roughness and surface energy, and a relatively uniform distribution of C, O, and Si elements can be observed on its surface.

[0068] 3. Hydrophobicity test Taking the superhydrophobic pure cotton fabric obtained in Example 5 as an example, the hydrophobic effect of the superhydrophobic fabric was tested. (1) Floating state: The superhydrophobic fabric was placed in deionized water, and the floating state of the superhydrophobic fabric in deionized water was observed as time increased. Figure 4 As shown; (2) Dynamic water contact effect: Under conditions of low adhesion (part a, the superhydrophobic fabric has a small contact angle with the water droplet) and high adhesion (part b, the superhydrophobic fabric has a large contact angle with the water droplet), the superhydrophobic fabric is moved up and down to make it contact the water droplet. The adhesion and penetration of the water droplet are observed using a high-speed camera, such as Figure 12 As shown; (3) Static water contact effect: Methylene blue dyed water droplets were dropped onto the surface of the original untreated fabric and the superhydrophobic fabrics obtained in Examples 1-5, respectively. After 5 minutes, the state of the water droplets on the two surfaces was compared, as shown. Figure 13 As shown.

[0069] Depend on Figure 4 As can be seen, after being left to stand in water for 60 days, the superhydrophobic fabric can still float stably on the water surface as the water evaporates, indicating that the superhydrophobic fabric prepared in Example 5 of this invention has a relatively stable hydrophobic effect.

[0070] 4. Self-cleaning test Taking the superhydrophobic pure cotton fabric of Example 3 as an example, the fabric surface was subjected to self-cleaning treatment. (1) At a 15° tilt angle, a certain concentration of soy sauce was taken using a disposable rubber-tipped dropper and dripped onto the original unmodified fabric and the superhydrophobic fabric to observe whether the fabric was soaked with soy sauce and whether the soy sauce stains on the fabric surface could be removed by adding deionized water. Figure 5 As shown; (2) At a 15° tilt angle, place the powder on the fabric surface, rinse with deionized water and dye with methylene blue to observe whether the fabric is wetted by the blue solution and whether the powder is removed, as shown. Figure 6 As shown; (3) Add common liquids (such as water, coffee, soy sauce and milk) to the surface of the fabric, and judge the hydrophobicity and stain resistance of the fabric by observing the shape of the droplets, such as Figure 7 As shown; (4) Immerse the fabric in the methylene blue dyeing water for 30 minutes, then remove it and observe the surface condition of the fabric, such as Figure 8 As shown.

[0071] The results are as follows Figure 5-8 As shown, soy sauce, powder and other contaminants on the fabric surface are completely removed, demonstrating that the superhydrophobic fabric prepared in Example 3 of this invention has good anti-fouling properties.

[0072] 4. Durability Testing The mechanical durability of the superhydrophobic fabric prepared in Example 4 was evaluated using abrasion tests. In the abrasion tests, the superhydrophobic fabric (2 cm × 4 cm) was placed on 400-mesh sandpaper, a load of 200 grams was applied, and it was dragged in one direction at a speed of 2 cm / s (15 cm per cycle). The change in water contact angle during 0 to 100 abrasion cycles was analyzed.

[0073] The results are as follows Figure 9 As shown, the water contact angle of the superhydrophobic fabric does not change significantly after 100 wear cycles, indicating that it has good durability.

[0074] 5. Oil / water separation test like Figure 10 As shown, oil / water separation was achieved using a simple apparatus consisting of a conventional filtration device and the superhydrophobic cotton fabric of Example 3 as the filter membrane. Subsequently, an oil / water mixture with a mass ratio of 1:1 (volume ratio) was poured into a glass filter cup positioned above the superhydrophobic sample, and the separation efficiency (η, %) was determined by gravimetric method using the following formula: ; in, m 0 and m 1 represents the mass of water before and after oil-water separation.

[0075] The results are as follows Figure 11 As shown in Table 1, it can be seen that water dyed with methylene blue and dichloromethane dyed with Sudan III are completely separated by superhydrophobic fabric.

[0076] 6. Contact angle test.

[0077] The static contact angle (WCA) of a 5 μL water droplet on the superhydrophobic fabric was measured using a contact angle meter (OSA 60, LAUDA Scientific, Germany). At least three samples prepared under the same conditions were tested, with five different regions tested for each fabric sample, and the average value was taken.

[0078] The results are as follows Figure 14 As shown in Table 1, it can be seen that Examples 1-5 have higher contact angles and exhibit superhydrophobic properties.

[0079] Table 1 The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions, characterized in that, Includes the following steps: After the fabric substrate is immersed in a eutectic solvent for surface rough etching pretreatment, it is immersed in a long-chain organosilane colloidal coating solution for reaction. After the reaction is completed, it is cleaned and dried to obtain the superhydrophobic fabric.

2. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 1, characterized in that, The fabric base material is a blend of one or more of the following: cotton, linen, cellulose fiber, and synthetic fiber base fabrics.

3. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 1, characterized in that, The hydrogen bond acceptor in the eutectic solvent is choline chloride, and the hydrogen bond donor is oxalic acid.

4. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 1, characterized in that, The surface roughening etching pretreatment is performed at a temperature of 60°C for 2 hours.

5. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 1, characterized in that, The impregnation reaction is carried out at a temperature of 20-35°C for 12 hours.

6. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 1, characterized in that, The preparation method of the long-chain organosilane colloidal coating solution includes the following steps: The long-chain organosilane is mixed with water and then vortexed for 20 seconds under open conditions. After that, it is ultrasonically treated for 20 seconds under sealed conditions, vortexed for 20 seconds, and then allowed to stand before adding n-hexane and mixing evenly to obtain the long-chain organosilane colloidal coating solution.

7. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 6, characterized in that, The long-chain organosilanes include one or more of octadecyltrichlorosilane, hexadecyltrichlorosilane, and dodecyltrichlorosilane.

8. The method for preparing a superhydrophobic fabric with self-cleaning and oil-water separation functions according to claim 6, characterized in that, The volume ratio of the long-chain organosilane to water is 1:0.02; The volume ratio of n-hexane to the solution obtained after standing is 20:

1.

9. A superhydrophobic fabric with self-cleaning and oil-water separation functions prepared by the preparation method according to any one of claims 1-8.

10. The application of a superhydrophobic fabric with self-cleaning and oil-water separation functions as described in claim 9 in self-cleaning functional surfaces, oil-water separation filter materials, or outdoor antifouling materials.

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