Preparation method and application of corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane

Abstract

This invention belongs to the technical field of oil-water separation materials, and particularly relates to a method for preparing and applying a superoleophilic, superhydrophobic, corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane. The method includes boiling the membrane in a sodium hypochlorite solution to remove wax and other substances from the fiber surface, washing it with ethanol and deionized water respectively, and then air-drying it at room temperature. Next, the membrane is impregnated in a nitrocellulose solution to coat the fiber surface with nitrocellulose, and then air-dried at room temperature. The resulting corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane exhibits a 0° contact angle between oil and the membrane surface in air, an oil-water contact angle greater than 160°, and a roll-off angle less than 5°. The prepared nitrocellulose cotton fabric filter membrane is used for the separation and treatment of oily wastewater—oil-water mixtures and water-in-oil emulsions. The nitrocellulose cotton fabric filter membrane is resistant to harsh environments such as strong acids, strong alkalis, and high salt concentrations; after being peeled off with tape, the surface is almost undamaged; it has the advantages of high separation efficiency, wide separation range, and multiple reusability.

Description

Technical Field

[0001] This invention belongs to the technical field of oily wastewater separation materials, and particularly relates to the preparation method and application of a superoleophilic, superhydrophobic, corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane. Background Technology

[0002] The large amounts of oily wastewater generated by chemical, catering, and oil companies seriously threaten ecosystems and environmental safety. To protect the environment and human health, efficient separation of oily wastewater is necessary so that the separated oil and water resources can be reused. Inspired by the highly wetted / non-wetting interfaces of natural organisms, numerous superwetting membranes have been artificially prepared for separating oil / water mixtures and emulsions. Generally, porous membranes with an oil-water contact angle greater than 150° and a roll-off angle less than 10° can be considered superhydrophobic membranes under oil. Currently, despite significant progress in superhydrophobic membranes under oil, the preparation process is often complex and the membranes have poor durability. When separating oily wastewater, the poor durability of these materials can lead to easy reaction of the membrane's chemical components, easy damage to its fine structure, a gradual decrease in separation efficiency with each separation cycle, and eventual loss of separation capability.

[0003] Considering the complex and harsh environments that sub-oil superhydrophobic oil-water separation membranes must withstand during separation, corrosion resistance is crucial for extending their lifespan. Commercial cotton fabrics, due to their large pore size, are unsuitable for separating oil / water mixtures and emulsions. Therefore, we developed a corrosion-resistant cotton fabric with sub-oil superhydrophobicity by treating it with an alkaline oxidant, impregnating it in a nitrocellulose solution, and coating its surface with nitrocellulose. A small amount of nitrocellulose adheres tightly to the cotton fabric surface via hydrogen bonds, forming a dense entangled structure. The introduction of this entangled structure significantly improves the cotton fabric's oleophilicity and corrosion resistance. The synergistic effect of the nanoporous structure formed by the nitrocellulose cotton fabric and the sub-oil superhydrophobic surface enables it to effectively separate various oil / water mixtures and emulsions. Importantly, the originally corrosion-sensitive cotton fabric exhibits excellent stability under corrosive media, friction damage, mechanical peeling, and ultraviolet radiation after being composited with nitrocellulose. Summary of the Invention

[0004] The purpose of this invention is to provide a superoleophilic, superhydrophobic, and corrosion-resistant nitrocellulose cotton fabric filter membrane for separating oily wastewater, which has high separation efficiency, wide separation range, and stable separation effect.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane, comprising the following steps:

[0007] Step S1: Cut the cotton fabric to obtain cotton fabric, wash the cotton fabric with deionized water and ethanol to remove dust and wax adhering to the surface of the cotton fabric, and dry it; immerse the cotton fabric in sodium hypochlorite solution, boil it, take it out, wash the cotton fabric with water, and dry it.

[0008] Step S2: Prepare a nitrocellulose solution using a mixed solvent of ether, ethanol and deionized water; immerse the cotton fabric treated with sodium hypochlorite in the nitrocellulose solution and then dry it to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

[0009] Preferably, the preparation method of the superoleophilic, superhydrophobic, corrosion-resistant nitrocellulose cotton fabric oil-containing wastewater separation filter membrane of the present invention comprises the following steps:

[0010] Step S1: Cut a 4cm x 4cm piece of cotton fabric. Wash the cotton fabric with deionized water and ethanol at 70°C for 30 minutes each to remove dust, wax, etc. adhering to the surface of the cotton fabric. Air dry at room temperature. Immerse the commercial cotton fabric in 100mL of sodium hypochlorite solution and boil at 100°C. Remove and wash the cotton fabric with sufficient water until the pH value of the wash water reaches 7. Air dry at room temperature.

[0011] Step S2: Prepare a nitrocellulose solution using a mixed solvent of ether, ethanol and deionized water; immerse the cotton fabric treated with sodium hypochlorite in the nitrocellulose solution and then dry it at room temperature for about 1 hour to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

[0012] Furthermore, the pretreatment in step S1 specifically involves removing dust, grease, and wax from the surface of the cellulose using deionized water, ethanol, and sodium hypochlorite, followed by a final water wash and air drying at room temperature.

[0013] Furthermore, the density of the plain weave cotton fabric in step S1 is 90-150 g / m³. 2 The concentration of sodium hypochlorite solution is 1-5%, and the cooking time is 0.5-2 hours.

[0014] Furthermore, the concentration of the nitrocellulose solution used in step S2 is 1-3%; the volume ratio of solvent ether:ethanol:water is 5:5:0-5:3:2, and the volume ratio of ether:(ethanol+water) is 1:1, and the impregnation time is 0.5-2 min.

[0015] Furthermore, in step S2, the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane has a contact angle of 0° between water and oil on its surface in air, and the oil-water contact angle of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is greater than 160°, while the roll-off angle is less than 5°.

[0016] Furthermore, the application of corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membranes involves separating oil-water mixtures and water-in-oil emulsions. When separating oil-water mixtures and water-in-oil emulsions, the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membranes need to be pre-wetted with a suitable oil. The oil in the oil-water mixtures and water-in-oil emulsions is at least one of chloroform, toluene, dichloroethane, kerosene, dichloroethane, kerosene, and dichloromethane.

[0017] The advantages of this invention are:

[0018] 1. The nitrocellulose cotton fabric oil-water separation filter membrane provided by the present invention has an oil-water contact angle of more than 160° in corrosive liquids (3M HCl, 3M NaOH and 20% NaCl solution by weight), and can separate oil-water mixtures with strong acids, strong bases and high salts.

[0019] 2. The corrosion-resistant nitrocellulose cotton fabric filter membrane provided by the present invention still maintains an oil-water contact angle of over 159° and a separation efficiency of over 99.5% after separating oil-water mixtures 20 times.

[0020] 3. The method for preparing the nitrocellulose cotton fabric oil-water separation filter membrane provided by this invention is simple, low-cost, and easy to industrialize. The filter membrane is stable under ultraviolet irradiation. Figure 8 d). After the filter membrane was irradiated with 365nm ultraviolet light for 24 hours, its water contact angle under oil remained essentially unchanged;

[0021] 4. The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane provided by this invention, under the strong adhesive force of 200 N / m of adhesive tape, withstands five tape peeling cycles (…). Figure 9 After the process, the surface of the nitrocellulose cotton fabric was almost undamaged, indicating that the corrosion-resistant nitrocellulose cotton fabric filter membrane has excellent mechanical stability. Attached Figure Description

[0022] Figure 1 (ac) optical images, (df) surface SEM images, and (gi) cross-sectional SEM images of cotton fabrics at different processing stages.

[0023] Figure 2 The N2 adsorption-desorption isotherms and pore size distributions are shown for (a) raw cotton fabric, (b) pretreated cotton fabric and (c) nitrocellulose cotton fabric.

[0024] Figure 3 (a) FTIR spectra, (b) thermal properties and (c) tensile properties of cotton fabrics at different treatment stages.

[0025] Figure 4(a) The wetting behavior of kerosene droplets on raw cotton fabric, pretreated cotton fabric and nitrocellulose cotton fabric in air, and (b) The comparison of the wetting behavior of oil and water on different samples in air.

[0026] Figure 5 The wetting behavior of water on different samples under (a) kerosene and (b) various oils.

[0027] Figure 6 The separation of oil-water mixtures by (a) raw cotton fabric, (b) pretreated cotton fabric, (c, d) nitrocellulose cotton fabric, (e) separation efficiency of nitrocellulose cotton fabric for five oil / water mixtures, and (f) cyclic separation performance of nitrocellulose cotton fabric for chloroform / water mixtures.

[0028] Figure 7 Separation performance of water-in-oil emulsions. (a, b) Optical microscopic images and digital photographs of chloroform-in-water emulsions and filtrates, (c, d) Water droplet size distribution in chloroform-in-water emulsions and filtrates, (e) oil flux and (f) water repellency of nitrocellulose cotton fabric for various water-in-oil emulsions.

[0029] Figure 8 To assess the stability of nitrocellulose cotton fabrics in harsh environments. (a) Abrasion test process, (b) Change in water contact angle under kerosene with the number of abrasion cycles (inset: SEM images after 0 and 20 abrasion cycles), (c) Change in water contact angle under kerosene with acid, alkali or salt concentration, and (d) Effect of UV irradiation time on water contact angle under kerosene.

[0030] Figure 9 Photographs of (ac) the tape peeling process and (d) after 5 peeling cycles. Detailed Implementation

[0031] Example 1:

[0032] Cut a 4cm x 4cm piece of cotton fabric. Wash the fabric with deionized water and ethanol at 70°C for 30 minutes each to remove dust, wax, and other adhering substances from the surface. Air dry at room temperature. Immerse the commercial cotton fabric in 100mL of 3% sodium hypochlorite solution and boil at 100°C for 1 hour. Remove and wash the fabric with sufficient water until the pH of the wash water reaches 7. Air dry at room temperature.

[0033] A 2% nitrocellulose solution was prepared by mixing diethyl ether, ethanol and water in a volume ratio of 5:4:1. The cotton fabric treated with sodium hypochlorite was immersed in the 2% nitrocellulose solution for 1 minute and then dried at room temperature for about 1 hour to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

[0034] The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane prepared by the above method was analyzed by scanning electron microscopy and automatic gas adsorption analyzer. The surface morphology was also measured, and the N2 adsorption-desorption isotherm was determined. The results showed that the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane has a dense porous structure. Figure 1 The average pore size is 15.3 nm. Figure 2 FTIR spectroscopy and thermal property curves indicate that nitrocellulose was successfully coated onto the surface of cotton fabric. Figure 3 Tensile properties indicate that the mechanical strength of cotton fabrics increases after being coated with nitrocellulose. Figure 3 The contact angle between water and oil on the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is 0°. Figure 4 The water contact angle under oil (kerosene, gasoline, toluene, petroleum ether, chloroform) is greater than 160°. The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane exhibits superoleophilicity and superhydrophobicity under both oil and water conditions. Figure 5 ).

[0035] Superoleophilic and superhydrophobic corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is used for oil-water mixtures. Figure 6 Separation treatment of water-in-oil emulsions () Figure 7 When separating oil-water mixtures and water-in-oil emulsions, a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane pre-wetted with oil is required. The oil in the oil-water mixture and emulsion is at least one of chloroform, toluene, dichloromethane, dichloroethane, and kerosene. After separating oil-water mixtures 20 times, the oil-water contact angle of the corrosion-resistant nitrocellulose cotton fabric filter membrane is still above 159°, and the separation efficiency is still higher than 99.5%.

[0036] Nitrocellulose cotton fabric filter membranes exhibit oil-water contact angles exceeding 160° in corrosive liquids (3M HCl, 3M NaOH, and 20% NaCl solutions). This superwetting property allows for the separation of strong acids, strong alkalis, and high-salt oil-water mixtures. Figure 8 c). Nitrocellulose cotton fabric filter membranes are stable under ultraviolet irradiation. After the filter membrane is irradiated with 365nm ultraviolet light for 24 hours, its water contact angle under oil remains essentially unchanged. Figure 8 d); The surface of the nitrocellulose cotton fabric filter membrane was subjected to a strong adhesive force of 200 N / m of tape, and after 5 tape peelings ( Figure 9 The surface of the nitrocellulose cotton fabric showed almost no damage, indicating that the nitrocellulose cotton fabric oil-water separation filter membrane has excellent mechanical stability. Figure 9 Furthermore, the method for preparing corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane provided by this invention is simple, low-cost, and easy to industrialize.

[0037] Example 2:

[0038] Cut a 4cm x 4cm piece of cotton fabric. Wash the fabric with deionized water and ethanol at 70°C for 30 minutes each to remove dust, wax, and other adhering substances from the surface. Air dry at room temperature. Immerse the commercial cotton fabric in 100mL of 1% sodium hypochlorite solution and boil at 100°C for 2 hours. Remove and wash the fabric with sufficient water until the pH of the wash water reaches 7. Air dry at room temperature.

[0039] A 1% nitrocellulose solution was prepared by mixing diethyl ether, ethanol and water in a volume ratio of 5:5:0. The cotton fabric treated with sodium hypochlorite was immersed in the 1% nitrocellulose solution for 2 minutes and then dried at room temperature for about 1 hour to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

[0040] The application of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is the same as in Example 1.

[0041] Example 3:

[0042] Cut a 4cm x 4cm piece of cotton fabric. Wash the fabric with deionized water and ethanol at 70°C for 30 minutes each to remove dust, wax, and other adhering substances from the surface. Air dry at room temperature. Immerse the commercial cotton fabric in 100mL of 5% sodium hypochlorite solution and boil at 100°C for 0.5 hours. Remove and wash the fabric with sufficient water until the pH of the wash water reaches 7. Air dry at room temperature.

[0043] A 3% nitrocellulose solution was prepared by mixing diethyl ether, ethanol and water in a volume ratio of 5:3:2. The cotton fabric treated with sodium hypochlorite was immersed in the 3% nitrocellulose solution for 0.5 min and then dried at room temperature for about 1 hour to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

[0044] The application of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is the same as in Example 1.

[0045] Experimental example:

[0046] I. Wettability Test

[0047] In air, the contact angle of n-hexane, xylene, cyclohexane, petroleum ether, diesel, gasoline, kerosene, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, and nitrobenzene on nitrocellulose cotton fabric is 0°. Figure 4 When nitrocellulose cotton fabric is placed in these oils, and water droplets are added to the surface of the fabric, the water droplets form almost perfect spheres in all the oils. Test results show that the contact angle of water with the nitrocellulose cotton fabric is higher than 160°, and the roll-off angle is less than 5°, indicating that the nitrocellulose cotton fabric has superoleophilic properties and superhydrophobic properties under oil conditions. Figure 5 ).

[0048] II. Oil-water mixture and emulsion separation test

[0049] Raw cotton fabric, pretreated cotton fabric, and nitrocellulose cotton fabric filter membranes were immobilized in a separation device to evaluate their ability to separate oil / water mixtures. Figure 6 (ad). To clearly observe the separation phenomenon, water and oil were stained with methylene blue and Sudan III, respectively. The oil-wetting properties of the raw and pretreated cotton fabrics allowed both oil and water to pass through under their own gravity, indicating that the raw and pretreated cotton fabrics could not separate the oil / water mixture. Figure 6 a, b). In contrast, nitrocellulose cotton fabric pre-wetted with oil can effectively separate oil / water mixtures, where oil easily penetrates the cotton fabric while water is repelled ( Figure 6 (c, d). Furthermore, light oil (kerosene) / water can also be separated under gravity using an inclined device. The separation efficiency of chloroform, toluene, dichloroethane, kerosene, and dichloromethane / water mixtures was measured using a nitrocellulose cotton fabric filter membrane, and the separation efficiency was greater than 99.5% for all mixtures. Taking the chloroform / water mixture as an example, after 5 cycles, the separation efficiency of the nitrocellulose cotton fabric remained above 99.5%, demonstrating the excellent reusability of the nitrocellulose cotton fabric.

[0050] Using Span 80 as a stabilizer, chloroform-in-water, toluene-in-water, dichloroethane-in-water, kerosene-in-water, and dichloromethane-in-water emulsions were prepared by stirring. The raw and pretreated cotton fabrics could not selectively separate the oil from the water-in-oil emulsions. That is, after separation, the filtrate in the filter flask remained opaque, indicating that the oil and water in the milky white emulsion had not been separated. Conversely, using a nitrocellulose cotton fabric filter membrane effectively separated the water-in-oil emulsions, in which the colorless oil was collected in the receiver. Figure 7 (Inset in b). Optical microscope images show numerous tiny water droplets randomly distributed within the emulsion. Figure 7 a), and the collected filtrate appears clear and transparent, without any water droplets. Figure 7 b). Dynamic light scattering results showed that the droplet size in the feed (chloroform) ranged from 300 to 1500 nm, while the maximum droplet size in the filtrate was less than 6 nm. Figure 7 (c, d). Similar efficient separation was also achieved in four other types of emulsions using Span 80 as a stabilizer, including toluene-in-water, dichloroethane-in-water, kerosene-in-water, and dichloromethane-in-water emulsions.

[0051] By calculating the flux of various emulsions penetrating nitrocellulose cotton fabric per unit time per unit area while maintaining an emulsion height of 5 cm, the flux of these emulsions penetrating the cotton fabric was obtained. Figure 7e). The permeation fluxes of chloroform-in-water, toluene-in-water, dichloroethane-in-water, kerosene-in-water, and dichloromethane-in-water emulsions were 111.0+6.4, 95.3+5.1, 114.1+5.9, 104.1+5.4, and 123.3+6.9 L·m⁻²·h⁻¹, respectively. These fluxes are inversely proportional to the viscosity of the oils (toluene < kerosene) but directly proportional to their densities (dichloroethane < dichloromethane < chloroform), making viscosity and density two key factors for flux. Figure 7 As shown in f, the water repellency (separation efficiency) of nitrocellulose cotton fabric for chloroform, toluene, dichloroethane, kerosene, and dichloromethane were ~99.85%, 99.84%, 99.85%, 99.83%, and 99.87%, respectively. These results indicate that nitrocellulose cotton fabric can effectively separate oil / water mixtures with high separation efficiency.

[0052] III. Stability of Nitrocellulose Cotton Fabrics

[0053] Nitrocellulose cotton fabrics used for oil-water separation are typically subjected to harsh conditions such as physical abrasion, corrosion from corrosive liquids, or decomposition by ultraviolet radiation. A sandpaper abrasion test was conducted to evaluate the mechanical durability of the nitrocellulose cotton fabric. Specifically, the nitrocellulose cotton fabric was secured to a glass slide with double-sided tape, and a 100g weight was placed on the fabric. The weight was slowly moved across the fabric in both horizontal and vertical directions, moving 10cm in each direction in each cycle. Figure 8 a) After 20 wear cycles ( Figure 8 (b) The oil-water contact angle of the nitrocellulose cotton fabric decreased only slightly from about 160° to about 159°, which may be because the morphology of the nitrocellulose cotton fabric did not change significantly. Figure 8 b) indicates that nitrocellulose cotton fabrics possess excellent abrasion resistance. Furthermore, the chemical stability of nitrocellulose cotton fabrics was assessed by contacting samples with corrosive droplets (such as strong acids, strong alkalis, and high-salt droplets). Figure 8 c). In oil, corrosive liquids (1M hydrochloric acid, 1M sodium hydroxide, and 10% sodium chloride solution) can form almost perfect spheres on the surface of nitrocellulose cotton fabric, with oil-water contact angles all exceeding 160°. With increasing concentrations of acid, alkali, or salt solutions, the contact angles of acids and salt solutions in oil (kerosene) remain essentially constant. Although the contact angle with alkaline water decreases slightly, the nitrocellulose cotton fabric still maintains superhydrophobicity in oil (oil-water contact angle >160°), indicating excellent resistance to strong acids (3M HCl), strong alkalis (3M NaOH), and high-salt solutions (20% NaCl). This result demonstrates that nitrocellulose cotton fabric exhibits excellent chemical resistance to corrosive liquids.

[0054] In addition, the stability of nitrocellulose cotton fabrics under ultraviolet irradiation was evaluated. Figure 8 d). After the filter membrane was irradiated with 365 nm ultraviolet light for 24 hours, its water contact angle under oil remained essentially unchanged, indicating that the nitrocellulose cotton fabric has excellent UV resistance. Furthermore, a tape peel test was conducted to evaluate the mechanical stability of the nitrocellulose cotton fabric. Figure 9 Under a strong adhesive force of 200 N / m, the surface of the nitrocellulose cotton fabric remained almost undamaged after five peeling cycles. The macroscopic and microscopic morphologies of the peeled tape surface indicate that the nitrocellulose cotton fabric possesses excellent mechanical stability.

Claims

1. A method for preparing a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane, characterized in that, It consists of the following steps: Step S1: Cut the cotton fabric to obtain cotton fabric, wash the cotton fabric with deionized water and ethanol to remove dust and wax adhering to the surface of the cotton fabric, and dry it; immerse the cotton fabric in sodium hypochlorite solution, boil it, take it out, wash the cotton fabric with water, and dry it. Step S2: Prepare a nitrocellulose solution using a mixed solvent of ether, ethanol and deionized water; immerse the cotton fabric treated with sodium hypochlorite in the nitrocellulose solution and then dry it to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure; the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane has a dense porous structure.

2. The method for preparing a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane as described in claim 1, characterized in that, In step S1, cut a 4cm×4cm piece of cotton fabric, wash the cotton fabric with deionized water and ethanol at 70°C for 30 minutes to remove dust, wax and other substances adhering to the surface of the cotton fabric, and air dry at room temperature; immerse the cotton fabric in 100mL of sodium hypochlorite solution and boil it at 100°C; take it out and wash the cotton fabric with sufficient water until the pH value of the washing water reaches 7, and air dry at room temperature. In step S2, a nitrocellulose solution is prepared using a mixed solvent of ether, ethanol and deionized water; the cotton fabric treated with sodium hypochlorite is immersed in the nitrocellulose solution and then dried at room temperature for 1 hour to obtain a corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane with a dense structure.

3. The method for preparing the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane as described in claim 1, characterized in that: The cotton fabric used in step S1 is plain weave cotton fabric with a density of 90-150 g / m2; the concentration of sodium hypochlorite solution is 1-5% by weight, and the cooking time is 0.5-2 hours. The sodium hypochlorite solution pretreatment is to further erode the grease, wax and some cellulose substances on the surface of cellulose, expose more polar groups, make the cotton fabric structure more compact, the surface more rough, and more easily combine with the polar groups of nitrocellulose.

4. The method for preparing the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane as described in claim 1, characterized in that: The nitrocellulose solution used in step S2 has a concentration of 1-3% by weight; the solvent for the nitrocellulose solution is the following solution: the volume ratio of solvent ether: ethanol: deionized water is 5:5:0-5:3:2, and the volume ratio of ether: ethanol and deionized water is 1:1, and the impregnation time is 0.5-2 min.

5. The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane obtained by the preparation method according to claim 1, characterized in that: In air, the contact angle between water and oil on the surface of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is 0°, the contact angle between oil and water is greater than 160°, and the roll-off angle is less than 5°.

6. The application of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane as described in claim 5, characterized in that: The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is used for the separation of oil-water mixtures and water-in-oil emulsions. When separating oil-water mixtures and water-in-oil emulsions, the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane needs to be pre-wetted with the appropriate oil. The oil in the oil-water mixture and water-in-oil emulsion is at least one of chloroform, toluene, dichloroethane, kerosene, dichloroethane, kerosene, and dichloromethane.

7. The application of the corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane as described in claim 6, characterized in that: The corrosion-resistant nitrocellulose cotton fabric oil-water separation filter membrane is resistant to harsh environments with strong acids, strong alkalis, and high salt content; it remains stable under ultraviolet radiation; and the surface of the nitrocellulose cotton fabric is almost undamaged after being peeled off with tape.

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