Dual-induced response super-hydrophobic fabric as well as preparation method and application thereof

Abstract

The invention discloses a dual-induced-response super-hydrophobic fabric, a preparation method and application, firstly, a silver nanowire aqueous solution is doped into an aqueous solution containing carboxylated chitosan and glutaraldehyde to form a mixed cross-linking solution, then a base material fabric is placed in the mixed cross-linking solution for dip-coating, loading and drying, and the dual-induced-response super-hydrophobic fabric is obtained. And soaking the fabric in an ethanol solution of n-dodecanethiol and 11-mercaptoundecanoic acid for modification to prepare the dual-induced response super-hydrophobic fabric with pH and electric field dual-induced response and excellent response cyclicity. The surface water contact angle of the prepared super-hydrophobic fabric reaches 153 degrees, pH response can be generated through induction of an electric field or an alkaline solution, the surface wettability of the double-induction-response super-hydrophobic fabric is converted, excellent response circularity is shown, the double-induction-response super-hydrophobic fabric has super-hydrophobicity / super-lipophilicity before response, and the double-induction-response super-hydrophobic fabric can be used for preparing the super-hydrophobic fabric. The method is used for separating heavy oil-water mixtures.

Description

Technical Field

[0001] The present invention relates to the technical field of super-hydrophobic fabrics, and in particular to a method for preparing a dual-induced response super-hydrophobic fabric having dual-induced response of pH and electric field and excellent response cyclicity, and an application of the fabric in controllable oil-water separation. Background Art

[0002] Oil-water separation materials with single wettability face challenges in the increasingly complex oil-water separation conditions. To this end, researchers have proposed oil-water separation materials with responsive properties. The responsiveness of these oil-water separation materials is triggered by changes in external environmental conditions, such as pH, temperature, light, electric fields, magnetic fields, salt, ions, and gases. Under these stimuli, the oil-water separation materials can transform from superhydrophobic / superoleophilic to superhydrophilic / underwater superoleophobic. It is worth noting that pH-only responsive materials not only have a small response range, but also have difficulty balancing the responsiveness and stability of surface chemicals during the response process, resulting in poor cyclability between wettability switching.

[0003] In recent years, researchers have proposed pH-responsive smart oil-water separation materials that can trigger wettability transitions under either acidic or alkaline conditions, achieving a wider response range. However, after the wettability of pH-responsive materials changes, it is difficult for the materials to return to their initial superhydrophobic state.

[0004] For example, after the acid-responsive group in the pH dual-responsive material responds, the recovery under alkaline conditions will cause the other part of the base-responsive group to deprotonate, affecting the recovery of the surface superwettability. At the same time, after the surface of the smart response material introduces a larger response range, its surface design is usually accompanied by a decrease in material stability in order to adapt to the demand for faster surface responsiveness. During the response cycle, due to the protonation and deprotonation, the interaction force between the modified substance and the substrate is reduced, resulting in detachment, loss of hydrophobicity and responsiveness, and greatly weakening its response cycle performance. On the other hand, the modified substances under the hydrophobic layer and the response layer will also affect the hydrophilicity of the fabric after response, resulting in a decrease in separation flux.

[0005] Therefore, solving the problems of weak response cycle performance of pH-responsive materials during wettability switching, small response range of pH-single-responsive materials, and difficulty in recovering super-wettability of pH-dual-responsive materials has become a key direction for in-depth research on intelligent responsive oil-water separation materials. Summary of the Invention

[0006] The present invention addresses the problems of weak response cycle performance of pH-responsive materials during wettability switching, small response range and long response time of pH-single-responsive intelligent oil-water separation materials, and difficulty in restoring super-hydrophobicity and acid-base resistance of pH-dual-responsive intelligent oil-water separation materials after response. The present invention provides a method for preparing a dual-induced response super-hydrophobic fabric with dual-induced response of pH and electric field and excellent response cycle, and its application in controllable oil-water separation.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a method for preparing a dual-induced response super-hydrophobic fabric, comprising the following steps:

[0008] Step S1, adding carboxylated chitosan and glutaraldehyde to an aqueous solution, maintaining the aqueous solution at a temperature of 60-80° C. and stirring for 0.5-1 hour, wherein the mass concentration of carboxylated chitosan is 0.5-2 wt %, and the mass concentration of glutaraldehyde is 0.01-0.1 wt %. After the stirring is completed, the silver nanowire aqueous solution is added thereto to form a mixed cross-linked solution, and the mass concentration of the silver nanowires in the mixed cross-linked solution is controlled to be 5-10 mg / mL;

[0009] Step S2, preparing a flexible conductive fabric, includes the following sub-steps:

[0010] S2.1, soaking sub-step, placing the substrate fabric in the mixed cross-linking solution prepared in step S1 and soaking for 30-60 minutes,

[0011] S2.2, drying and crosslinking sub-step, after taking out, crosslinking reaction in 60-80℃ environment for 0.5-2h,

[0012] S2.3, repeating the sub-steps of soaking and drying and cross-linking 3-5 times to prepare a flexible conductive fabric;

[0013] Step S3,

[0014] First, the flexible conductive fabric prepared in step S2 is placed in a modification solution for modification for 18-24 hours, and then taken out and dried in a temperature environment of 60-80°C for 0.5-2 hours to prepare a dual-induced response super-hydrophobic fabric.

[0015] The modified solution is an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, wherein the molar ratio of n-dodecyl mercaptan to 11-mercaptoundecanoic acid is 1.5 to 4:1, and the total concentration of n-dodecyl mercaptan and 11-mercaptoundecanoic acid in the ethanol solution is 1 to 2 mol / L.

[0016] The thiol modification reaction formula of flexible conductive fabric is shown in formula (1):

[0017] Ag+R-SH→Ag-SR (1)

[0018] Wherein, R- is -(CH2) 10 COOH or -(CH2) 11 CH3.

[0019] The mass ratio of the silver nanowires to the carboxylated chitosan is 7 to 9:1. The aspect ratio of the silver nanowires is controlled to be 300 to 1000:1. Prior to performing step S2, the substrate fabric is plasma treated. Prior to modification and compounding, the substrate fabric is plasma treated to reduce its water contact angle to less than 10°. The substrate fabric and the resulting dual-induced responsive superhydrophobic fabric comprise polyester fibers.

[0020] A preferred technical solution is a method for preparing a dual-induced response super-hydrophobic fabric, comprising the following steps:

[0021] Step S1, adding carboxylated chitosan and glutaraldehyde to an aqueous solution, maintaining the temperature of the aqueous solution at 60-80° C. and stirring for 0.5-1 hour, wherein the mass concentration of carboxylated chitosan is 0.5-2wt%, and the mass concentration of glutaraldehyde is 0.01-0.1wt%. After the stirring is completed, the silver nanowire aqueous solution is added thereto to form a mixed cross-linked solution, and the mass concentration of the silver nanowires in the mixed cross-linked solution is controlled to be 5-10 mg / mL, wherein the aspect ratio of the silver nanowires is controlled to be 300-1000:1, and the mass ratio of the silver nanowires to the carboxylated chitosan is 7-9:1;

[0022] Plasma treatment is performed on the substrate fabric. Before modification and compounding, the substrate fabric is subjected to plasma treatment to make the water contact angle of the substrate fabric less than 10°, and then step S2 is performed;

[0023] Step S2, preparing a flexible conductive fabric, includes the following sub-steps:

[0024] S2.1, soaking sub-step, placing the substrate fabric in the mixed cross-linking solution prepared in step S1 and soaking for 30-60 minutes,

[0025] S2.2, drying and crosslinking sub-step, after taking out, crosslinking reaction in 60-80℃ environment for 0.5-2h,

[0026] S2.3, repeating the sub-steps of soaking and drying and cross-linking 3-5 times to prepare a flexible conductive fabric;

[0027] Step S3,

[0028] First, the flexible conductive fabric prepared in step S2 is placed in a modification solution for modification for 18-24 hours, and then taken out and dried in a temperature environment of 60-80°C for 0.5-2 hours to prepare a dual-induced response super-hydrophobic fabric.

[0029] The modified solution is an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, wherein the molar ratio of n-dodecyl mercaptan to 11-mercaptoundecanoic acid is 1.5 to 4:1, and the total concentration of n-dodecyl mercaptan and 11-mercaptoundecanoic acid in the ethanol solution is 1 to 2 mol / L.

[0030] The thiol modification reaction formula of flexible conductive fabric is shown in formula (1):

[0031] Ag+R-SH→Ag-SR (1)

[0032] Wherein, R- is -(CH2) 10 COOH or -(CH2) 11 CH3.

[0033] A dual-induction responsive super-hydrophobic fabric is prepared according to the method for preparing a dual-induction responsive super-hydrophobic fabric.

[0034] The dual-induced responsive super-hydrophobic fabric is obtained by placing the flexible conductive fabric in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid for thiol modification for 18-24 hours and then taking it out and drying it. The dual-induced responsive super-hydrophobic fabric comprises polyester fiber.

[0035] The n-dodecanethiol and the 11-mercaptoundecanoic acid are thiol-modified on the flexible conductive fabric and grafted onto the silver nanowires. The silver nanowires are loaded on the surface of the polyester fiber of the dual-induction responsive super-hydrophobic fabric. The surface of the polyester fiber of the dual-induction responsive super-hydrophobic fabric is coated with the silver nanowires, effectively constructing roughness on the surface of the polyester fiber and achieving a surface resistance of 0.5Ω / cm2 for the dual-induction responsive super-hydrophobic fabric. 2 , used to achieve super hydrophobicity, in the infrared spectrum of the dual induced response super hydrophobic fabric, the -1 、2848cm -1 The stretching vibration peaks of -CH3 and -CH2- belonging to the n-dodecanethiol appear at 2972 ​​cm -1 、1714cm -1 、1249cm -1 、1101cm -1 , 725cm -1 The infrared characteristic peak at is significantly weakened; the surface water contact angle of the dual-induced response superhydrophobic fabric reaches 153°-158°.

[0036] The invention discloses an application of a dual-induced responsive super-hydrophobic fabric. The dual-induced responsive super-hydrophobic fabric is prepared according to the preparation method of the dual-induced responsive super-hydrophobic fabric. The dual-induced responsive super-hydrophobic fabric is characterized in that the dual-induced responsive super-hydrophobic fabric is used in the controllable oil-water separation technology of oil-water mixture, and the dual-induced responsive super-hydrophobic fabric has dual induced response of pH and electric field and excellent response cyclicity.

[0037] According to a further technical solution, the oil-water mixture comprises a heavy oil-water mixture and a light oil-water mixture, wherein the heavy oil-water mixture and the light oil-water mixture are any one of n-hexane, cyclohexane, petroleum ether, toluene, xylene, dichloromethane, chloroform, edible oil and pump oil mixed with water to form an oil-water mixture.

[0038] According to a further technical solution, the volume mixing ratio of water to oil in the oil-water mixture is 1:1.

[0039] A further technical solution is that in the oil-water separation device of the light oil-water mixture, since the water in the light oil-water mixture isolates the light oil and the dual-induced responsive super-hydrophobic fabric and cannot be effectively separated, the surface of the dual-induced responsive super-hydrophobic fabric is transformed into super-hydrophilic through external stimulation.

[0040] There are two types of external stimuli:

[0041] First, an alkaline solution is added to the water in the oil-water mixture to make the water alkaline, thereby inducing the surface of the dual-induced response superhydrophobic fabric to respond to pH and become superhydrophilic. Formula (2) is the reaction formula of the pH response process.

[0042] R1-COOH+OH - →R1-COO - +H2O (2),

[0043] Wherein, R1- is -(CH2) 10 SAg;

[0044] Secondly, the dual-induced responsive super-hydrophobic fabric is immersed in water of an oil-water mixture and the dual-induced responsive super-hydrophobic fabric is used as the cathode. A graphite electrode is inserted into the water of the oil-water mixture and the graphite electrode is used as the anode. The water electrolysis process is carried out in the water to form an alkaline condition near the cathode, thereby inducing the surface of the dual-induced responsive super-hydrophobic fabric to respond to pH and become super-hydrophilic. Formula (2) is the cathode reaction formula of the fabric water electrolysis process.

[0045] 2H2O+2e - →H2↑+2OH - (3);

[0046] The pH response process that occurs during subsequent induction is consistent with formula (2);

[0047] The alkaline environment deprotonates the carboxyl groups grafted onto the fabric surface. The surface becomes dominated by carboxylate ions, and the molecular chains stretch outward, exposing the groups and increasing their affinity for water, transforming the fabric from superhydrophobic to superhydrophilic.

[0048] In addition, the super-hydrophilic fabric after pH response can be restored by acid solution treatment. Formula (4) is the acid treatment reaction formula,

[0049] R1-COO - +H + →R1-COOH (4),

[0050] The hydrogen ions in the acidic solution combine with the carboxylate ions after pH response, so that the carboxyl groups are restored, and the molecular chain segments collapse due to the action of hydrogen bonds and stack on each other. At this time, the hydrophobicity dominated by long-chain alkyl groups is restored on the surface of the fabric, and it changes from superhydrophilic to superhydrophobic.

[0051] The advantages of the present invention compared with the prior art are:

[0052] 1. The present invention first incorporates an aqueous solution of silver nanowires into an aqueous solution containing carboxylated chitosan and glutaraldehyde to form a mixed cross-linked solution, then places a substrate fabric in the mixed cross-linked solution for dipping, loading and drying, forms a conductive layer on the surface of the substrate fabric and obtains a flexible conductive fabric, and finally immerses it in an ethanol solution of n-dodecanethiol and 11-mercaptoundecanoic acid for modification to obtain a dual-induction-responsive super-hydrophobic fabric having both pH and electric field dual-responsiveness and excellent response cyclicity; the super-hydrophobic fabric prepared by the present invention has a surface water contact angle of 153°, and can be induced to respond to a pH by an electric field or an alkaline solution, so that the surface wettability of the dual-induction-responsive super-hydrophobic fabric is converted to cope with complex oil-water separation environments, and its pH response cycle number reaches more than 13 times, showing excellent response cyclicity, and the dual-induction-responsive super-hydrophobic fabric of the present invention has super-hydrophobicity / super-oleophilicity before response, and is used for separating heavy oil-water mixtures, and is converted to super-hydrophilicity / underwater super-oleophobicity after response, and is used for separating light oil-water mixtures.

[0053] The process of the present invention is simple, easy to implement mass production, and the mass production process cost is low. In addition, the dual-induced responsive superhydrophobic fabric prepared by the present invention has good superhydrophobicity, responsiveness, response cycle, weather resistance and acid and alkali resistance, can meet the needs of rapid separation of oil-water mixtures, and realize material surface wettability conversion under multiple response conditions.

[0054] 2. The dual-induced responsive super-hydrophobic fabric prepared by the present invention has good super-hydrophobicity and conductive properties. It can induce the dual-induced responsive super-hydrophobic fabric to undergo pH response under the conditions of applying voltage and adding alkaline solution in water, so that the surface wettability of the dual-induced responsive super-hydrophobic fabric is changed from super-hydrophobicity to super-hydrophilicity. It can also change the surface wettability of the dual-induced responsive super-hydrophobic fabric from super-oleophilicity to underwater super-oleophobicity, and can accurately separate oil or water from the oil-water mixture as required.

[0055] 3. Compared with similar intelligent response oil-water separation materials, the dual-induced response super-hydrophobic fabric of the present invention can not only effectively expand the response range, but also solve the problem that the pH dual-responsive oil-water separation material is difficult to restore super-hydrophobicity after response. At the same time, the addition of carboxylated chitosan and glutaraldehyde increases the hydrophilicity, responsiveness and stability of the fabric, greatly improving the separation flux and recycling performance of the fabric.

[0056] 4. The fabric prepared by the present invention has excellent superhydrophobicity and can effectively separate heavy oil-water mixtures under natural conditions. The fabric surface contains pH-responsive substances that can induce responses through two different external stimuli, causing the wettability of the fabric surface to change, thereby achieving on-demand separation of oil-water mixtures.

[0057] 5. The fabric prepared by the present invention has excellent response cycle performance, and has good pH response cycle performance induced by alkaline solution. Carboxylated chitosan and glutaraldehyde are introduced as molecular binders during its preparation process. A strong interaction force is generated between the carboxylated chitosan and the silver nanowires, which can anchor the silver nanowires and form an effective conductive path on the fabric surface, thereby greatly improving the pH response cycle performance. At the same time, the carboxyl group in the carboxylated chitosan increases the responsiveness of the pH response material and ensures the hydrophilicity under the responsive hydrophobic layer, which can effectively improve the separation flux before and after the response.

[0058] 6. Compared with traditional pH single-responsive oil-water separation materials and new pH dual-responsive oil-water separation materials, the dual-responsive superhydrophobic fabric of the present invention has dual-responsiveness of pH and electric field and excellent response cyclicity. It has a wide response range and rich response conditions, and is easier to restore the superhydrophobic state to ensure controllable wettability switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the surface wettability conversion of the prepared dual-induced responsive superhydrophobic fabric with dual induced responses of pH and electric field and excellent response cyclicity.

[0060] Figure 2 This is an infrared spectrum of the raw material substrate fabric and the prepared dual-induced response superhydrophobic fabric with dual-induced response of pH and electric field and excellent response cyclicity in this Example 1.

[0061] Figure 3 This is a scanning electron microscope image of the raw material base fabric in Example 1.

[0062] Figure 4 This is a scanning electron microscope image of the dual-induced responsive superhydrophobic fabric prepared in Example 1, which has dual induced responses to pH and electric field and excellent response cyclicity. DETAILED DESCRIPTION

[0063] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring the water at 60-70° C. for 0.5-1 hour, wherein the mass concentration of the carboxylated chitosan is controlled to be 1-2 wt % and the mass concentration of the glutaraldehyde is controlled to be 0.01-0.05 wt %, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. In the cross-linked mixed solution, the mass concentration of silver nanowires is 5-8 mg / mL, the mass ratio of silver nanowires to carboxylated chitosan is 8-9:1, and the aspect ratio of the silver nanowires is controlled to be 1000:1; then, a substrate fabric with an area of ​​30 mm×30 mm is plasma treated and immersed in the above cross-linked mixed solution for 30-40 minutes, then taken out and cross-linked at 75-80°C for 0.5-1 hour, and the soaking-drying process is repeated 4-5 times to obtain a flexible conductive fabric; finally, the flexible conductive fabric is immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, the total concentration of n-dodecyl mercaptan and 11-mercaptoundecanoic acid in ethanol is controlled to be 1.5-2 mol / L, and the molar ratio of n-dodecyl mercaptan to 11-mercaptoundecanoic acid is 7:3-6:4. After the flexible conductive fabric is modified for 20-24 hours, it is taken out and dried at 70-80° C. for 0.5-1 hour to prepare a dual-induced response super-hydrophobic fabric with dual-induced response of pH and electric field and excellent response cyclicity.

[0064] The prepared superhydrophobic fabric, which exhibits dual pH and electric field induced responses and excellent cyclic response, is pH-responsive. Under neutral or acidic conditions, the carboxyl groups of 11-mercaptoundecanoic acid hydrogen bond, causing the molecular chains to collapse and stack. The long-chain alkyl groups of n-dodecyl mercaptan extend outward, providing low surface energy for the fabric. The fabric exhibits a superhydrophobic state. Under alkaline conditions, the carboxyl groups on 11-mercaptoundecanoic acid undergo deprotonation, and the molecular chains extend outward, exposing the groups on the fabric surface. This enhances the fabric's affinity for water and renders the fabric superhydrophilic.

[0065] Within the above parameter range, the prepared dual-induced response super-hydrophobic fabric with dual induced response of pH and electric field and excellent response cyclicity has better performance. The prepared super-hydrophobic fabric was tested according to the test method of Example 1, and the surface water contact angle of the fabric was 153±1°. The response time of droplets with a pH of 13 was 30-40s, and droplets with pH of 1 and 7 maintained a stable super-hydrophobic state on the surface of the fabric, and the measured response cycle number was 13±1 times. In addition, the electric field induced response time of the prepared super-hydrophobic fabric was 60-80s, and its separation flux for heavy oil-water mixture before response was 16844.7±400L·m -2 ·h -1 The separation efficiency is 95.5±1%, and the separation flux of light oil-water mixture after response is 17250.3±400 L·m -2 ·h -1 , the separation efficiency is 97.8±1%. At this time, the mass ratio of silver nanowires to carboxylated chitosan can ensure the optimal conductivity and stability of the fabric, and is not easily affected by organic and aqueous solvents, so that the fabric has a stable response cycle. At the same time, the molar ratio of n-dodecyl mercaptan and 11-mercaptoundecanoic acid affects the hydrophobicity and responsiveness of the fabric. The molar ratio range of 7:3-6:4 ensures both the superhydrophobicity of the fabric surface and extremely fast dual-induced responsiveness. Therefore, the fabric prepared in the above parameter range has superhydrophobicity, can undergo rapid wettability conversion, and has a stable response cycle.

[0066] To further illustrate the present invention, specific examples and comparative examples are provided below for illustration.

[0067] Example 1

[0068] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring at 60°C for 1 hour, wherein the mass concentration of carboxylated chitosan is controlled to be 1wt% and the mass concentration of glutaraldehyde is controlled to be 0.01wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 5 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinking mixture for 30 minutes. The fabric was then removed and crosslinked at 80°C for 1 hour. This soaking-drying process was repeated four times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 6:4. After modification for 24 hours, the fabric was removed and dried at 80°C for 1 hour, resulting in a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response.

[0069] Figure 1 The infrared spectra of the original substrate fabric and the dual-induced super-hydrophobic fabric with pH and electric field dual-induced response and excellent response cycle in Example 1 are shown in Figure 1. Compared with the original substrate fabric, the infrared spectrum of the dual-induced super-hydrophobic fabric with pH and electric field dual-induced response and excellent response cycle is at 2916 cm -1 、2848cm -1 The stretching vibration peaks of -CH3 and -CH2- belonging to n-dodecanethiol appeared at 2972cm -1 、1714cm -1 、1249cm -1 、1101cm -1 , 725cm -1 The infrared characteristic peak at was significantly weakened, indicating the successful loading of silver nanowires and the successful grafting of n-dodecyl mercaptan and 11-mercaptoundecanoic acid.

[0070] Figure 2 and Figure 3 Scanning electron micrographs of the original substrate fabric and the resulting super-hydrophobic fabric with dual pH and electric field responses and excellent cyclic response properties are shown in Figure 1. Compared to the smooth, clean surface of the original substrate fabric, the fiber surface of the resulting super-hydrophobic fabric with dual pH and electric field responses and excellent cyclic response properties is coated with a large number of silver nanowires, effectively creating a rough surface that contributes to super-hydrophobicity.

[0071] In order to evaluate the superhydrophobicity of the fabric, the contact angle of the fabric was measured using a contact angle meter, and the contact angle was measured to be 153°. The results are listed in Table 1 (test comparison table).

[0072] In order to evaluate the pH response performance of the fabric induced by pH solution, the superhydrophobic fabric was placed on a flat surface and water drops of pH 1, 7, and 13 were added to three different places on the fabric. The pH response performance induced by pH alkaline solution was evaluated by recording the time it took for the water drop of pH 13 to penetrate the fabric surface and observing whether the water drop of pH 1 and 7 still maintained the superhydrophobic state on the fabric within 5 minutes. When the alkaline solution of pH 13 was added to the fabric surface, the hydroxide ions in the pH solution reacted with the -COOH response groups on the fabric surface to form -COOH - The time it takes for the pH solution to induce the pH response of the superhydrophobic fabric is 30 seconds. The results are listed in Table 1.

[0073] To evaluate the electric field-induced pH response of the fabric, a simple self-assembled oil-water separation device was tested. The device consists of two upper and lower glass tubes with an inner diameter of 20 mm, a superhydrophobic fabric, a clamp, and a beaker. Water and n-hexane were sequentially added to the separation device from above. A power cord was connected to the fabric as the cathode, and a graphite electrode connected to the other end of the power cord was inserted into the water below the n-hexane as the anode. Voltages of 10 V, 15 V, and 20 V were applied to the fabric, and the time it took for water to break through the fabric barrier was recorded. The n-hexane was also observed to be trapped above the fabric after water broke through the fabric. When the fabric and graphite electrode jointly electrolyzed water, alkaline conditions were generated on the cathode surface. The generated hydroxide ions reacted with the responsive groups on the fabric surface, causing the fabric's surface wettability to switch. The prepared superhydrophobic fabric exhibited a 15 V electric field-induced pH response time of 60 s. The results are listed in Table 1.

[0074] In order to evaluate the response cycle performance of the fabric, the fabric is placed on a plane and a water droplet of 7 pH is added to any position of the surface. If the water droplet maintains super-hydrophobic state on the fabric surface, a water droplet of 13 pH is added to the same position to convert the surface wettability of the fabric. The water droplet of 1 pH is processed to restore super-hydrophobicity to the fabric surface at the place. The wetting-recovery process is repeated in the same place until super-hydrophobicity cannot be recovered by acid treatment after response wetting or wetting. The number of times of recording the response cycle is 13 times, and the results are listed in Table 1.

[0075] In order to evaluate the oil-water separation performance of the fabric, a simple oil-water separation device was assembled according to the above method to test the oil-water separation performance of the fabric. Among them, the fabric was fixed in the middle of the glass tube as a filter membrane, and 10 mL of either oil in n-hexane or dichloromethane and 10 mL of water were mixed in a beaker to simulate an oil-water mixture, and then poured into the beaker from the top of the glass tube. Compared with the superhydrophobic-superoleophilic fabric before pH response, during the separation process of the heavy oil-water mixture, the heavy oil will pass through the superhydrophobic fabric, while the water will be retained above the fabric, realizing oil-water separation; compared with the superhydrophilic-underwater superoleophobic fabric after pH response, during the separation process of the light oil-water mixture, the water will pass through the superhydrophilic fabric, while the oil will be retained above the fabric. The results show that the separation flux of the prepared superhydrophobic fabric for the heavy oil-water mixture before response is 16844.7 L·m -2 ·h -1 , the separation efficiency is 95.5%. After the response, the separation flux of light oil-water mixture is 17250.3L·m -2 ·h -1 The separation efficiency was 97.8%. The results are listed in Table 1.

[0076] Example 2

[0077] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring at 70°C for 1 hour, wherein the mass concentration of carboxylated chitosan is controlled to be 2wt% and the mass concentration of glutaraldehyde is controlled to be 0.01wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 7 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinking mixture for 60 minutes. The fabric was then removed and crosslinked at 70°C for 2 hours. This soaking-drying process was repeated three times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 7:3. After the flexible conductive fabric was modified for 24 hours and then dried at 80°C for 2 hours, a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response was prepared.

[0078] The prepared superhydrophobic fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was 156°. The response time of a droplet with a pH of 13 was 53 seconds, and droplets with pHs of 1 and 7 remained in a stable superhydrophobic state on the fabric surface. The measured response cycle number was 12 times. In addition, the prepared superhydrophobic fabric had an electric field induced response time of 86 seconds, and its separation flux for a heavy oil-water mixture before the response was 16898.5 L·m -2 ·h -1 The separation efficiency is 95.6%, and the separation flux of light oil-water mixture after response is 17063.4 L·m -2 ·h -1 The separation efficiency was 96.4%. The results are listed in Table 1.

[0079] Example 3

[0080] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring at 60°C for 1 hour, wherein the mass concentration of carboxylated chitosan is controlled to be 1wt% and the mass concentration of glutaraldehyde is controlled to be 0.05wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 7 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 7:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinking mixture for 40 minutes. The fabric was then removed and crosslinked at 80°C for 1 hour. This soaking-drying process was repeated three times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 4:1. After the flexible conductive fabric was modified for 24 hours and then dried at 80°C for 0.5 hour, a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response was prepared.

[0081] The prepared superhydrophobic fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was 155°. The response time of a droplet with a pH of 13 was 51 seconds, and droplets with pHs of 1 and 7 remained in a stable superhydrophobic state on the fabric surface. The number of response cycles was measured to be 10. In addition, the electric field-induced pH response time of the prepared superhydrophobic fabric was 135 seconds, and its separation flux for heavy oil-water mixture before response was 16765 7L·m -2 ·h -1 , the separation efficiency is 96.1%, and the separation flux of light oil-water mixture after response is 16992.8L·m -2 ·h -1The separation efficiency was 96.3%. The results are listed in Table 1.

[0082] Example 4

[0083] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring at 60°C for 1 hour, wherein the mass concentration of carboxylated chitosan is controlled to be 2wt% and the mass concentration of glutaraldehyde is controlled to be 0.05wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 5 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinking mixture for 50 minutes. The fabric was then dried at 80°C for 1 hour, and the immersion-drying process was repeated five times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 4:1. After the flexible conductive fabric was modified for 20 hours and then dried at 80°C for 1 hour, a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response was prepared.

[0084] The prepared superhydrophobic fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was 153°. The response time of a droplet with a pH of 13 was 67 seconds, and droplets with pHs of 1 and 7 remained in a stable superhydrophobic state on the fabric surface. The measured response cycle number was 11 times. In addition, the prepared superhydrophobic fabric had an electric field-induced pH response time of 126 seconds, and its separation flux for heavy oil-water mixture before response was 16539.9 L·m -2 ·h -1 , the separation efficiency is 96.5%, and the separation flux of light oil-water mixture after response is 17075.8L·m -2 ·h -1 The separation efficiency was 98.1%. The results are listed in Table 1.

[0085] Example 5

[0086] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring at 40°C for 1 hour, wherein the mass concentration of carboxylated chitosan is controlled to be 1wt% and the mass concentration of glutaraldehyde is controlled to be 0.01wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 10 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was then plasma-treated and immersed in the crosslinking mixture for 30 minutes. The fabric was then removed and crosslinked at 80°C for 1 hour. This soaking-drying process was repeated three times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 1 mol / L and a molar ratio of 4:1. After the flexible conductive fabric was modified for 24 hours and then dried at 80°C for 1 hour, a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response was prepared.

[0087] The prepared superhydrophobic fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was 155°. The response time of a droplet with a pH of 13 was 34 seconds, and droplets with pHs of 1 and 7 remained in a stable superhydrophobic state on the fabric surface. The measured response cycle number was 12 times. In addition, the electric field-induced pH response time of the prepared superhydrophobic fabric was 69 seconds, and its separation flux for heavy oil-water mixture before response was 16987.4 L·m -2 ·h -1 , the separation efficiency is 94.5%, and the separation flux of light oil-water mixture after response is 17012.9 L·m -2 ·h -1 The separation efficiency was 96.7%. The results are listed in Table 1.

[0088] Example 6

[0089] A method for preparing a dual-induced responsive superhydrophobic fabric comprises the following steps: first, adding carboxylated chitosan and glutaraldehyde to water and stirring the water at 80°C for 0.5h, wherein the mass concentration of the carboxylated chitosan and the mass concentration of the glutaraldehyde are controlled to be 2wt% and 0.1wt%, and then adding a silver nanowire aqueous solution to form a cross-linked mixed solution. The crosslinking mixture contained a silver nanowire concentration of 10 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. A 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinking mixture for 30 minutes. The fabric was then removed and crosslinked at 60°C for 2 hours. This soaking-drying process was repeated four times to produce a flexible conductive fabric. Finally, the fabric was immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 7:3. After the flexible conductive fabric was modified for 18 hours and then dried at 60°C for 0.5 hours, a dual-responsive superhydrophobic fabric with both pH and electric field responses and excellent cyclic response was prepared.

[0090] The prepared superhydrophobic fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was 158°. The response time of a droplet with a pH of 13 was 48 seconds, and droplets with pHs of 1 and 7 remained in a stable superhydrophobic state on the fabric surface. The measured response cycle number was 11 times. In addition, the prepared superhydrophobic fabric had an electric field-induced pH response time of 93 seconds, and its separation flux for a heavy oil-water mixture before the response was 16790.3 L·m -2 ·h -1 , the separation efficiency is 95%, and the separation flux of light oil-water mixture after response is 17276.2 L·m -2 ·h -1 The separation efficiency was 97.9%. The results are listed in Table 1.

[0091] Comparative Example 1

[0092] First, carboxylated chitosan and glutaraldehyde were added to water and stirred at 80°C for 1 hour. The carboxylated chitosan concentration was controlled to be 4 wt% and the glutaraldehyde concentration was controlled to be 2 wt%. Then, an aqueous solution of silver nanorods was added to form a cross-linked mixture. The cross-linked mixture contained silver nanorods (aspect ratio <300:1) at a concentration of 5 mg / mL and a mass ratio of silver nanorods to carboxylated chitosan of 4:1. Next, a 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the cross-linked mixture for 30 minutes. The fabric was then removed and cross-linked at 80°C for 0.5 hours. This soaking-drying process was repeated four times to produce a flexible conductive fabric. Finally, the flexible conductive fabric was immersed in an ethanol solution containing n-dodecanethiol and 11-mercaptoundecanoic acid. The total concentration of n-dodecanethiol and 11-mercaptoundecanoic acid in the ethanol was controlled to be 2 mol / L, and the molar ratio of n-dodecanethiol to 11-mercaptoundecanoic acid was 7:3. The flexible conductive fabric was modified for 24 hours and then dried at 80°C for 1 hour to obtain the fabric.

[0093] The prepared fabric was tested according to the test method of Example 1. The surface water contact angle of the fabric was only 153°. The response time of the droplet with a pH of 13 was 65s, and the droplets with pH of 1 and 7 remained stably superhydrophobic on the fabric surface. The measured response cycle number was 5 times. Due to the small aspect ratio of the silver nanorods used and the excessive amount of mixed cross-linking substances, it was difficult to form an effective conductive path on the fabric surface, resulting in the failure of the electric field induced pH response. The separation flux of the fabric for the heavy oil-water mixture before response was 16623.7 L·m -2 ·h -1 The separation efficiency is 94%, and the separation flux of light oil-water mixture after response is 16623.7L·m -2 ·h -1 The separation efficiency was 94%. The results are listed in Table 1.

[0094] Comparative Example 2

[0095] First, carboxylated chitosan and glutaraldehyde were added to water and stirred at 80°C for 1 hour. The carboxylated chitosan concentration was controlled to be 0.5 wt% and the glutaraldehyde concentration was controlled to be 0.01 wt%. Then, an aqueous solution of silver nanowires was added to form a cross-linked mixture. The cross-linked mixture contained a silver nanowire concentration of 10 mg / mL, a silver nanowire to carboxylated chitosan mass ratio of 9:1, and an aspect ratio of 1000:1. Next, a 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the cross-linked mixture for 30 minutes. The fabric was then removed and cross-linked at 80°C for 1 hour. This soaking and drying process was repeated four times to produce a flexible conductive fabric. Finally, the flexible conductive fabric was immersed in an ethanol solution containing n-dodecanethiol and 11-mercaptoundecanoic acid. The total concentration of n-dodecanethiol and 11-mercaptoundecanoic acid in the ethanol was controlled to be 2 mol / L, and the molar ratio of n-dodecanethiol to 11-mercaptoundecanoic acid was 1:1. The flexible conductive fabric was modified for 24 hours and then dried at 80°C for 1 hour to obtain the fabric.

[0096] The prepared fabric was tested according to the test method of Example 1. Due to the excessive proportion of 11-mercaptoundecanoic acid in the modified substance, the fabric surface could not reach a superhydrophobic state after modification, and the contact angle was only 137°. The response time of the droplet with a pH of 13 was 12s, but the droplets with pH of 1 and 7 could not maintain a superhydrophobic state on the fabric surface, and the response cycle performance could not be measured. The electric field induced pH response time was 41s. In addition, due to the low hydrophobicity of the fabric, the heavy oil-water separation failed. The separation flux of the light oil-water mixture after the fabric response was 17223.7L·m -2 ·h -1 The separation efficiency was 96.7%. The results are listed in Table 1.

[0097] Comparative Example 3

[0098] A 30 mm x 30 mm substrate fabric was plasma-treated and then immersed in a 5 mg / mL silver nanowire aqueous solution for 30 minutes. The fabric was then removed and cross-linked at 40°C for 1 hour. This soaking-drying process was repeated once to produce a flexible conductive fabric. The fabric was then immersed in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, with a total concentration of 2 mol / L and a molar ratio of 7:3. The fabric was modified for 12 hours and then dried at 80°C for 1 hour to produce the fabric.

[0099] The prepared fabric was tested using the test method described in Example 1. Due to the lack of a crosslinking solution to act as a molecular binder between the fabric and the silver nanowires, and the insufficient number of immersion cycles, the silver nanowire loading on the fabric surface was low, and some of the silver nanowires detached during the modification process, resulting in a contact angle of only 93°. Furthermore, water droplets on the fabric surface gradually wet the fabric over time, making it impossible to observe and record the response time of droplets at a pH of 13, and the response cycle performance could not be measured. Due to the short shedding and modification time of the silver nanowires, the hydrophobicity of the fabric surface was too low, resulting in the failure of the electric field-induced pH response and oil-water separation. The results are listed in Table 1.

[0100] Comparative Example 4

[0101] First, carboxylated chitosan and glutaraldehyde were added to water and stirred at 80°C for 1 hour. The carboxylated chitosan concentration was controlled to be 1 wt% and the glutaraldehyde concentration was controlled to be 0.01 wt%. Then, an aqueous solution of silver nanowires was added to form a crosslinked mixture. The crosslinked mixture contained a silver nanowire concentration of 10 mg / mL, a silver nanowire-to-carboxylated chitosan mass ratio of 1:1, and an aspect ratio of 1000:1. Next, a 30 mm x 30 mm substrate fabric was plasma-treated and immersed in the crosslinked mixture for 30 minutes. The fabric was then removed and crosslinked at 80°C for 2 hours. This soaking-drying process was repeated five times to produce a flexible conductive fabric. Finally, the flexible conductive fabric was immersed in an ethanol solution containing n-dodecanethiol and 11-mercaptoundecanoic acid. The total concentration of n-dodecanethiol and 11-mercaptoundecanoic acid in the ethanol was controlled to be 2 mol / L, and the molar ratio of n-dodecanethiol to 11-mercaptoundecanoic acid was 9:1. The flexible conductive fabric was modified for 24 hours and then dried at 80°C for 1 hour to obtain the fabric.

[0102] The prepared super-hydrophobic fabric was tested according to the test method of Example 1, and the surface water contact angle of the fabric was 155°. Due to the excessive proportion of n-dodecyl mercaptan in the modified substance, the content of 11-mercaptoundecanoic acid was low, the pH response was invalid, and the response cycle performance could not be measured. At the same time, the mixing ratio of silver nanowires to carboxylated chitosan was too small, and the polymer affected the construction of the conductive path, resulting in the failure of the electric field induced pH response test. The separation flux of the heavy oil-water mixture before the response was measured to be 17302.5 L·m -2 ·h -1 The separation efficiency was 96%. The fabric lost its pH response and could not effectively separate the light oil-water mixture. The results are listed in Table 1.

[0103] Table 1 Water contact angle, pH solution induced pH response time, electric field induced pH response time, separation flux and separation efficiency of heavy / light oil-water mixture, and response cycle number of the fabrics prepared in the examples of the present invention and the comparative examples.

[0104]

[0105]

[0106] Table 1 - Test comparison table

[0107] In Table 1, “-” indicates that the performance cannot be tested

[0108] As can be seen from the contact angle, pH response time, and oil-water separation data in Table 1, the fabrics prepared in Examples 1-6 exhibit superhydrophobicity, with water contact angles of all above 150°. Furthermore, the fabrics exhibit excellent dual-induced responses to pH and electric fields, effectively separating heavy oil-water mixtures before and after the response. The response cycles can each reach over 10 cycles, indicating good stability of the surface-modified material. These results demonstrate that the superhydrophobic fabrics prepared can achieve controlled separation of different oil-water mixtures through dual-induced pH responses.

[0109] Compared to Example 1, the fabrics prepared in Comparative Examples 1-4 exhibited problems such as unclear surface roughness, unconnected conductive pathways, and easy shedding of the silver nanowires due to factors such as a small aspect ratio of the silver nanowires, a lack of or excessive crosslinking solution, insufficient number of immersion cycles, an unreasonable ratio of modifying agents, and a short modification time. These factors resulted in the fabrics failing to achieve both superhydrophobicity and dual-induced pH responsiveness. These results demonstrate that the aspect ratio of the silver nanowires, number of immersion cycles, ratio of modifying agents, and the mixing ratio of the crosslinking solution all significantly influence the superhydrophobicity, conductivity, pH responsiveness, and cyclic response of the superhydrophobic fabrics.

[0110] The comparison of the technical solutions of this patent and similar invention patents is shown in Table 2.

[0111]

[0112]

[0113] Table 2 - Comparison of technical solutions between this patent and similar invention patents

[0114] Performance testing method:

[0115] (1) Contact angle test: The contact angle of the fabric was measured using the SDC-200S contact angle meter produced by Dongguan Shengding Precision Instrument Co., Ltd. The water droplet was 5 μL. Each sample was measured 5 times and the average value was taken.

[0116] (2) Response cycle test: Use alkaline solution to wet any position of the finished fabric, and then add acidic solution to restore the superhydrophobicity. If the fabric surface at that position can be restored to the superhydrophobic state, repeat the wetting-recovery process at that position until no response wetting can be performed or the superhydrophobicity cannot be restored by acid treatment after wetting. The number of response cycles is recorded.

[0117] (3) Oil-water separation test: Oil-water separation is carried out in a self-assembled simple oil-water separation device. The oil-water mixture is poured from the top of the separation device, and the separated oil / water is collected at the bottom of the separation device. The separation flux and separation efficiency are calculated by measuring the separation time and the volume of oil / water collected after separation.

[0118] The above examples are only a few specific preparation methods and detailed data of the present invention. A person skilled in the art may make several modifications or substitutions, which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the appended claims.

Claims

1. A method for preparing a dual-induced response super-hydrophobic fabric, characterized in that: The following steps are included: Step S1, adding carboxylated chitosan and glutaraldehyde to an aqueous solution, maintaining the aqueous solution at a temperature of 60-80° C. and stirring for 0.5-1 hour, wherein the mass concentration of carboxylated chitosan is 0.5-2 wt %, and the mass concentration of glutaraldehyde is 0.01-0.1 wt %. After the stirring is completed, the silver nanowire aqueous solution is added thereto to form a mixed cross-linked solution, and the mass concentration of the silver nanowires in the mixed cross-linked solution is controlled to be 5-10 mg / mL; Step S2, preparing a flexible conductive fabric, includes the following sub-steps: S2.1, soaking sub-step, placing the substrate fabric in the mixed cross-linking solution prepared in step S1 and soaking for 30-60 minutes, S2.2, drying and crosslinking sub-step, after taking out, crosslinking reaction in 60-80℃ environment for 0.5-2h, S2.3, repeating the sub-steps of soaking and drying and cross-linking 3-5 times to prepare a flexible conductive fabric; Step S3, First, the flexible conductive fabric prepared in step S2 is placed in a modification solution for modification for 18-24 hours, and then taken out and dried in a temperature environment of 60-80°C for 0.5-2 hours to prepare a dual-induced response super-hydrophobic fabric. The modified solution is an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid, wherein the molar ratio of n-dodecyl mercaptan to 11-mercaptoundecanoic acid is 1.5 to 4:1, and the total concentration of n-dodecyl mercaptan and 11-mercaptoundecanoic acid in the ethanol solution is 1 to 2 mol / L. The thiol modification reaction formula of flexible conductive fabric is shown in formula (1): Ag+R-SH→Ag-SR (1) Wherein, R- is -(CH2) 10 COOH or -(CH2) 11 CH3.

2. The method for preparing a dual-induced response super-hydrophobic fabric according to claim 1, wherein: The mass ratio of the silver nanowires to the carboxylated chitosan is 7 to 9:

1.

3. The method for preparing a dual-induced response super-hydrophobic fabric according to claim 1, wherein: The aspect ratio of the silver nanowires is controlled within a range of 300 to 1000:

1.

4. The method for preparing a dual-inductive response super-hydrophobic fabric according to claim 1, wherein: Before performing step S2, the substrate fabric is first subjected to plasma treatment. Before the modified composite, the substrate fabric is subjected to plasma treatment so that the water contact angle of the substrate fabric is less than 10°. The substrate fabric and the dual-induced response superhydrophobic fabric finally prepared contain polyester fibers.

5. A dual-inductively responsive super-hydrophobic fabric, prepared according to the method for preparing a dual-inductively responsive super-hydrophobic fabric according to any one of claims 1 to 4, characterized in that: The dual-induced responsive super-hydrophobic fabric is obtained by placing the flexible conductive fabric in an ethanol solution containing n-dodecyl mercaptan and 11-mercaptoundecanoic acid for thiol modification for 18-24 hours and then taking it out and drying it. The dual-induced responsive super-hydrophobic fabric comprises polyester fiber. The n-dodecanethiol and the 11-mercaptoundecanoic acid are thiol-modified on the flexible conductive fabric and grafted onto the silver nanowires. The silver nanowires are loaded on the surface of the polyester fiber of the dual-induction responsive super-hydrophobic fabric. The surface of the polyester fiber of the dual-induction responsive super-hydrophobic fabric is coated with the silver nanowires, effectively constructing roughness on the surface of the polyester fiber and achieving a surface resistance of 0.5Ω / cm2 for the dual-induction responsive super-hydrophobic fabric. 2 , used to achieve superhydrophobicity.

6. The dual-inductive-responsive super-hydrophobic fabric according to claim 5, characterized in that: In the infrared spectrum of the dual-induced responsive super-hydrophobic fabric, the -1 、2848cm -1 The stretching vibration peaks of -CH3 and -CH2- belonging to the n-dodecanethiol appear at 2972 ​​cm -1 、1714cm -1 、1249cm -1 、1101cm -1 , 725cm -1 The infrared characteristic peak at is significantly weakened; The surface water contact angle of the dual-induced responsive superhydrophobic fabric reaches 153°-158°.

7. An application of a dual-inductively responsive super-hydrophobic fabric, wherein the dual-inductively responsive super-hydrophobic fabric is prepared according to the method for preparing a dual-inductively responsive super-hydrophobic fabric according to any one of claims 1 to 4, characterized in that: The application of dual-induced responsive superhydrophobic fabrics in the controllable oil-water separation technology of oil-water mixtures. The dual-induced responsive superhydrophobic fabrics have dual induced responses of pH and electric field and excellent response cyclicity.

8. The use of a dual-induced response super-hydrophobic fabric according to claim 7, characterized in that: The oil-water mixture includes a heavy oil-water mixture and a light oil-water mixture. The heavy oil-water mixture and the light oil-water mixture are any one of n-hexane, cyclohexane, petroleum ether, toluene, xylene, dichloromethane, chloroform, edible oil and pump oil mixed with water to form an oil-water mixture.

9. The use of a dual-induced response super-hydrophobic fabric according to claim 7, characterized in that: The volume mixing ratio of water to oil in the oil-water mixture is 1:

1.

10. The use of a dual-induced response super-hydrophobic fabric according to claim 7, characterized in that: In the oil-water separation device for the light oil-water mixture, effective separation cannot be performed because the water in the light oil-water mixture isolates the light oil and the dual-induced responsive super-hydrophobic fabric. The surface of the dual-induced responsive super-hydrophobic fabric is transformed into super-hydrophilic through external stimulation. There are two types of external stimuli: First, an alkaline solution is added to the water in the oil-water mixture to make the water alkaline, thereby inducing the surface of the dual-induced response superhydrophobic fabric to respond to pH and become superhydrophilic. Formula (2) is the reaction formula of the pH response process. R1-COOH+OH - →R1-COO - +H2O (2), Wherein, R1- is -(CH2) 10 SAg; Secondly, the dual-induced responsive super-hydrophobic fabric is immersed in water of an oil-water mixture and the dual-induced responsive super-hydrophobic fabric is used as the cathode. A graphite electrode is inserted into the water of the oil-water mixture and the graphite electrode is used as the anode. The water electrolysis process is carried out in the water to form an alkaline condition near the cathode, thereby inducing the surface of the dual-induced responsive super-hydrophobic fabric to respond to pH and become super-hydrophilic. Formula (2) is the cathode reaction formula of the fabric water electrolysis process. <h2 style=";text-align:left;direction:ltr">2H2O+2e<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> →H2↑+2OH<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> (3); The pH response process that occurs during subsequent induction is consistent with formula (2); The alkaline environment causes the carboxyl groups grafted onto the fabric surface to undergo a deprotonation process. The fabric surface is dominated by carboxylate ions, and the molecular chains stretch outward to expose the groups, thereby enhancing the affinity with water, thereby transforming from superhydrophobic to superhydrophilic. In addition, the super-hydrophilic fabric after pH response can be restored by acid solution treatment. Formula (4) is the acid treatment reaction formula, R1-COO - +H + →R1-COOH (4), The hydrogen ions in the acidic solution combine with the carboxylate ions after pH response, so that the carboxyl groups are restored, and the molecular chain segments collapse due to the action of hydrogen bonds and stack on each other. At this time, the hydrophobicity dominated by long-chain alkyl groups is restored on the surface of the fabric, and it changes from superhydrophilic to superhydrophobic.

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