An oil-water separation material, its preparation method, and its application.

Abstract

This invention belongs to the field of oily wastewater treatment technology, specifically relating to an oil-water separation material, its preparation method, and its application. The preparation method of the oil-water separation material includes: (1) surface modification of a stainless steel mesh using a dopamine hydrochloride aqueous solution; (2) preparation of a stainless steel mesh with a polydopamine / copper nanocluster coating using a liquid-phase reduction method; (3) preparation of a sodium octadecyl dithiocarbamate solution of a certain concentration; and (4) obtaining a stainless steel mesh with a surface deposited double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating by solution impregnation. The modified octadecylamine-modified metal mesh superhydrophobic material prepared by this invention has a simple preparation process, low production cost, good mechanical stability, and resistance to organic solvents, salt solutions, and acid / alkali solutions. The resulting modified stainless steel mesh exhibits excellent superhydrophobicity (contact angle >151°) and high separation efficiency (>96.2%).

Description

Technical Field

[0001] This invention belongs to the field of oily wastewater treatment technology, specifically relating to an oil-water separation material, its preparation method, and its application. Background Technology

[0002] Frequent oil spills and the continuous discharge of oily wastewater pose a significant threat to the ecological environment, marine ecosystems, and human health. Therefore, efficient oil-water separation methods are crucial for solving these environmental problems.

[0003] There are many traditional methods for separating oil-water mixtures, which can be divided into three categories based on their separation principles: physical separation, chemical treatment, and biodegradation. Physical separation methods mainly include centrifugation, gravity separation, adsorption, and membrane separation. Chemical treatment methods mainly include chemical demulsification and oxidation-reduction methods. Biodegradation methods introduce microorganisms into oily wastewater, utilizing their metabolism to degrade oil pollutants and purify water resources. Traditional methods have various drawbacks, including low separation efficiency, long processing times, and secondary pollution, which limit their practical application. Therefore, developing inexpensive, simple, and easy-to-operate oil-water separation technologies to achieve rapid and effective separation of oil and water is of paramount importance.

[0004] In recent years, superhydrophobic metal meshes used for filtering oil-water mixtures have been widely reported. In particular, superhydrophobic stainless steel meshes have become one of the most promising candidates for treating marine oil spills and industrial oily wastewater due to their low cost and satisfactory durability. However, superhydrophobic metal meshes currently face the following technical problems: (1) The preparation of superhydrophobic metal meshes is subject to harsh conditions, complex processes, and high costs, especially requiring expensive precision equipment such as high-temperature furnaces, vacuum equipment, and coating spray guns, which result in high investment and maintenance costs; (2) In the process of preparing superhydrophobic metal meshes, improper surface treatments or coatings, such as acid etching, may cause the metal surface to become brittle or peel off, thereby weakening its mechanical strength; (3) The use of thiol modifiers causes environmental pollution; (4) The chemical incompatibility between the metal mesh and the superhydrophobic coating may result in weak interaction, thereby affecting the adhesion of the coating, and consequently making the stability and recyclability of most superhydrophobic stainless steel meshes unsatisfactory.

[0005] Therefore, there is an urgent need to develop a method for preparing superhydrophobic metal wire mesh for oily wastewater treatment that has minimal impact on the mechanical properties of the metal itself, mild reaction conditions, and safe and simple process operation. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an oil-water separation material, its preparation method, and its applications. The oil-water separation material provided by this invention uses a stainless steel mesh as a substrate, a bilayer polydopamine / copper nanoclusters as an intermediate layer, and sodium octadecyl dithiocarbamate as a superhydrophobic modifier, achieving an oil-water separation efficiency exceeding 96%.

[0007] This invention is achieved through the following technical solution:

[0008] A method for preparing an oil-water separation material includes the following steps:

[0009] (1) Pre-treat the stainless steel mesh;

[0010] (2) Place the stainless steel mesh into a weak alkaline hydrochloric acid dopamine solution, stir it for a period of time at a suitable temperature, wash and dry it to obtain a stainless steel mesh with polydopamine deposited on the surface.

[0011] (3) Immerse the stainless steel mesh with polydopamine deposited on the surface obtained in step (2) into CuCl2 solution, stir at room temperature for a certain time, add NaBH4 aqueous solution, stir for a certain time, clean and dry to a constant weight to obtain a stainless steel mesh with polydopamine / copper nanocluster coating deposited on the surface.

[0012] (4) Repeat steps (2) to (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanocluster coating deposited on the surface;

[0013] (5) The stainless steel mesh obtained in step (4) is placed in sodium octadecyl dithiocarbamate solution for modification. After modification for a period of time, it is taken out and air-dried naturally to obtain a stainless steel mesh with a double layer of polydopamine / copper nanoclusters and sodium octadecyl dithiocarbamate coating deposited on the surface, which is the oil-water separation material.

[0014] Further, step (1) specifically involves: selecting a stainless steel mesh with a mesh size of 600-1000 mesh, and sequentially ultrasonically treating the stainless steel mesh with ethanol, acetone, and deionized water, followed by air drying at room temperature. In this step, ultrasonic treatment can effectively remove surface contaminants and oil films.

[0015] Further, in step (2), the weakly alkaline dopamine hydrochloride solution is prepared by dissolving dopamine hydrochloride in Tris-HCl buffer solution, and the pH of the prepared weakly alkaline dopamine hydrochloride solution is 7~8.8; and the concentration of the weakly alkaline dopamine hydrochloride solution is 2 g·L. −1 .

[0016] Under alkaline conditions, dopamine hydrochloride can spontaneously polymerize, adhering firmly to the surface of stainless steel mesh without special treatment, forming a robust polydopamine deposition layer. The surface of the polydopamine deposition layer can be grafted with metal ions and low surface energy substances, thereby endowing the metal material surface with superhydrophobic properties. Therefore, in this invention, the pH of the dopamine hydrochloride solution needs to be limited to 7-8.8.

[0017] Further, in step (2), the stirring temperature is 20~60 ℃, and the stirring time is 4~24 h. Controlling the stirring conditions in this step allows for more uniform deposition of the polydopamine coating and achieves a suitable thickness. In this invention, controlling the temperature and stirring time optimizes the uniformity and thickness of the polydopamine coating, ensuring uniform deposition of the coating on the stainless steel mesh surface. Appropriate stirring conditions can also promote the polymerization reaction, improving the coating's adhesion and structural stability. Higher temperatures can accelerate the polymerization reaction and increase the deposition rate, but may lead to uneven coating or excessive thickness; while lower temperatures help form a more uniform coating, but the deposition rate is slower. Therefore, finding the optimal temperature range and stirring time is crucial for obtaining an ideal polydopamine coating.

[0018] Furthermore, in step (3), the concentration of CuCl2 solution is 0.02~0.1 mol / L; the concentration of NaBH4 aqueous solution is 0.04~0.08 mol / L;

[0019] The CuCl2 solution was stirred for 0.5 h, and after adding NaBH4 aqueous solution, stirring was continued for 2 h. The NaBH4 aqueous solution can remove Cu from the solution. 2+ Completely reduced to copper nanoparticles.

[0020] Further, in step (5), the method for preparing the sodium octadecyl dithiocarbamate solution is as follows:

[0021] Dissolve 0.001–0.01 mol of octadecylamine and 0.001–0.01 mol of sodium hydroxide in 85 mL of diethyl ether and stir to obtain a suspension. Add 0.04–0.4 mol of carbon disulfide to the suspension to obtain a mixed solution. Stir the mixed solution vigorously (400–500 rpm) for 0.5–2 h at room temperature. Collect the resulting white solid product, dry it, and obtain sodium octadecyl dithiocarbamate.

[0022] The prepared sodium octadecyl dithiocarbamate was dispersed in ethanol to prepare a sodium octadecyl dithiocarbamate solution.

[0023] Further, in step (5), the concentration of the sodium octadecyl dithiocarbamate solution is 0.15~0.45 g·L.−1 The modification time is 2-6 hours. Under the concentration and modification time specified in this invention, sodium octadecyl dithiocarbamate can uniformly adhere to the material surface, forming a stable and durable hydrophobic layer, improving water resistance and anti-fouling ability. At the same time, it achieves economical and effective modification at a low concentration and has the advantages of low toxicity and environmental friendliness.

[0024] An oil-water separation material, wherein the oil-water separation material is based on a stainless steel mesh, with a double layer of polydopamine / copper nanoclusters as an intermediate layer, and sodium octadecyl dithiocarbamate as a superhydrophobic modifier.

[0025] Furthermore, the oil-water separation material has an oil-water separation efficiency exceeding 96% and a static contact angle with water greater than 151°.

[0026] An application of an oil-water separation material, wherein the oil-water separation material is used for oily wastewater separation and leaked crude oil recovery.

[0027] Technical principle of this invention:

[0028] This invention utilizes the self-polymerization of dopamine hydrochloride to form a polydopamine deposition layer on the surface of a stainless steel mesh. Furthermore, the polydopamine deposition layer can serve as a secondary modification platform, adsorbing Cu from the solution. 2+ Using NaBH4 aqueous solution as a nucleation surface, copper ions in the solution can be completely reduced to copper nanoparticles, thereby constructing micro-nano structures (copper nanoclusters). Furthermore, polydopamine possesses superior adhesion, enabling it to bond with stainless steel mesh while simultaneously adhering copper nanoparticles to the surface, creating the desired roughness; then, a hydrophobic agent is used for low surface energy modification.

[0029] Beneficial technical effects of the present invention:

[0030] The oil-water separation material preparation method provided by this invention is simple, the raw materials are widely available, and it is environmentally friendly. The oil-water separation efficiency exceeds 96%, and the oil-water separation process can be repeated more than 40 times while still maintaining excellent hydrophobicity (contact angle >151°) and high efficiency (over 96.2%).

[0031] The oil-water separation material provided by this invention can be easily produced on a large scale without the need for special equipment.

[0032] The oil-water separation material provided by this invention uses sodium octadecyl dithiocarbamate as a superhydrophobic modifier. Compared with thiol modifiers, sodium octadecyl dithiocarbamate exists in solid form and is not easily volatile, so it releases less harmful gas during application. It is also relatively stable in the environment and usually exhibits low bioaccumulation and toxicity, making it relatively environmentally friendly.

[0033] The oil-water separation material provided by this invention can be used to separate various oil-water mixtures under natural gravity conditions, and has important application potential in the treatment of oily wastewater and marine oil spills. Attached Figure Description

[0034] Figure 1 This is a scanning electron microscope image of the original stainless steel mesh.

[0035] Figure 2 This is a scanning electron microscope image of the oil-water separation material prepared in an embodiment of the present invention.

[0036] Figure 3 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in the embodiments of the present invention.

[0037] Figure 4 This is a graph showing the oil-water separation efficiency of the oil-water separation material prepared in the embodiments of the present invention.

[0038] Figure 5 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in Example 2 of the present invention.

[0039] Figure 6 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in Example 3 of the present invention.

[0040] Figure 7 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in Example 4 of the present invention.

[0041] Figure 8 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in Example 5 of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0044] In the following examples, room temperature refers to 25±5°C.

[0045] Example 1: This example provides a method for preparing an oil-water separation material, including the following steps:

[0046] (1) Select a stainless steel mesh with an 800-mesh aperture and ultrasonically clean it for 15 minutes in sequence with ethanol, acetone, and deionized water to remove surface contaminants. Then, allow it to air dry at room temperature. In this embodiment, the ultrasonic power is 200W and the ultrasonic frequency is 40kHz.

[0047] (2) Dopamine hydrochloride was dissolved in a buffer solution prepared with Tris-HCl at pH=7 to obtain a concentration of 2 g·L⁻¹. −1 Dopamine hydrochloride solution;

[0048] The cleaned stainless steel mesh from step (1) was placed in the prepared dopamine hydrochloride solution and stirred at 25 °C for 20 h. Subsequently, the resulting sample was rinsed with water and finally dried at 85 °C to obtain a stainless steel mesh with polydopamine deposited on it.

[0049] (3) The stainless steel mesh with polydopamine deposited in step (2) was immersed in a 0.08 M CuCl2 solution and stirred at 25 °C for 0.5 h (300 rpm). Then, an aqueous solution of NaBH4 was added to a final concentration of 0.05 M, and the mixture was stirred for 2 h to completely reduce the copper ions bound to the polydopamine coating. Finally, the modified stainless steel mesh was removed, cleaned, and dried to a constant weight to obtain a stainless steel mesh with polydopamine / copper nanoclusters deposited on it.

[0050] (4) Repeat steps (2) to (3) on the stainless steel mesh with polydopamine / copper nanoclusters obtained in step (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanoclusters deposited on the surface.

[0051] (5) Place the stainless steel mesh containing the bilayer polydopamine / copper nanoclusters obtained in step (4) into a solution with a concentration of 0.3 g·L⁻¹. -1 The material was further modified in a sodium octadecyl dithiocarbamate solution at 25°C (or within the range of 25°C ± 5°C) for 4 h. Then, it was removed and air-dried to obtain a stainless steel mesh with a surface deposited with a double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating, which is an oil-water separation material.

[0052] Figure 1 This is a scanning electron microscope image of the original stainless steel mesh. Figure 2 The oil-water separation material prepared in this embodiment (material modified with sodium octadecyl dithiocarbamate) Figure 1 Scanning electron microscope (SEM) images of the original stainless steel mesh are shown, revealing a very smooth surface. After superhydrophobic modification (see...),... Figure 2 The surface of the stainless steel mesh is completely covered with small particles, which are randomly distributed and form irregular aggregates. Figure 3This is a measurement diagram of the water contact angle of the oil-water separation material prepared in this embodiment.

[0053] Example 2: This example provides a method for preparing an oil-water separation material, including the following steps:

[0054] (1) Select a stainless steel mesh with a sieve size of 600 mesh, and ultrasonically clean it for 15 minutes in sequence with ethanol, acetone and deionized water to remove surface contaminants. After that, let it air dry at room temperature.

[0055] (2) Dopamine hydrochloride was dissolved in a buffer solution prepared with Tris-HCl at pH 8.5 to obtain a concentration of 1 g·L⁻¹. −1 Dopamine hydrochloride solution;

[0056] The cleaned stainless steel mesh from step (1) was placed in the prepared dopamine hydrochloride solution and stirred at 20 °C for 24 h. The resulting sample was then rinsed with water and finally dried at 85 °C to obtain a stainless steel mesh deposited with polydopamine.

[0057] (3) The stainless steel mesh with polydopamine deposited in step (2) was immersed in a CuCl2 solution with a concentration of 0.05 M and stirred at 25 °C for 1.0 h (300 rpm). Then, an aqueous solution of NaBH4 was added to a final concentration of 0.04 M, and the mixture was stirred for 3 h to completely reduce the copper ions bound to the polydopamine coating. Finally, the modified stainless steel mesh was removed, cleaned, and dried to a constant weight to obtain a stainless steel mesh with a polydopamine / copper nanocluster coating.

[0058] (4) Repeat steps (2) to (3) on the stainless steel mesh obtained in step (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanoclusters deposited on the surface.

[0059] (5) Place the stainless steel mesh obtained in step (4) into a solution with a concentration of 0.15 g·L⁻¹. -1 The material was modified in a sodium octadecyl dithiocarbamate solution for 6 h. Then, it was removed and air-dried to obtain a stainless steel mesh with a surface deposited with a double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating, thus preparing the oil-water separation material. Figure 5 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in this embodiment.

[0060] Example 3: This example provides a method for preparing an oil-water separation material, including the following steps:

[0061] (1) Select a stainless steel mesh with a sieve size of 1000 mesh, and ultrasonically clean it for 15 minutes in sequence with ethanol, acetone and deionized water to remove surface contaminants. After that, let it air dry at room temperature.

[0062] (2) Dopamine hydrochloride was dissolved in a buffer solution prepared with Tris-HCl at pH 8.8 to obtain a concentration of 4 g·L⁻¹. −1 Dopamine hydrochloride solution;

[0063] The cleaned stainless steel mesh from step (1) was placed in the prepared dopamine hydrochloride solution and stirred at 40 °C for 15 h. The resulting sample was then rinsed with water and finally dried at 85 °C to obtain a stainless steel mesh deposited with polydopamine.

[0064] (3) The stainless steel mesh with polydopamine deposited in step (2) was immersed in a 0.1 M CuCl2 solution and stirred at 25 °C for 0.5 h (300 rpm). Then, an aqueous solution of NaBH4 was added to a final concentration of 0.08 M, and the mixture was stirred for 1 h to completely reduce the copper ions bound to the polydopamine coating. Finally, the modified stainless steel mesh was removed, cleaned, and dried to a constant weight to obtain a stainless steel mesh with a polydopamine / copper nanocluster coating.

[0065] (4) Repeat steps (2) to (3) on the stainless steel mesh obtained in step (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanoclusters deposited on the surface.

[0066] (5) Place the stainless steel mesh obtained in step (4) into a solution with a concentration of 0.45 g·L⁻¹. -1 The material was modified in a sodium octadecyl dithiocarbamate solution for 2 hours. Then, it was removed and air-dried to obtain a stainless steel mesh with a surface deposited with a double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating, thus preparing the oil-water separation material. Figure 6 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in this embodiment.

[0067] Example 4: This example provides a method for preparing an oil-water separation material, including the following steps:

[0068] (1) Select a stainless steel mesh with an 800-mesh sieve and ultrasonically clean it for 15 minutes in sequence with ethanol, acetone and deionized water to remove surface contaminants. Then, let it air dry at room temperature.

[0069] (2) Dopamine hydrochloride was dissolved in a buffer solution prepared with Tris-HCl at pH 7.5 to obtain a concentration of 3 g·L⁻¹. −1 A solution of dopamine hydrochloride.

[0070] The cleaned stainless steel mesh from step (1) was placed in the prepared dopamine hydrochloride solution and stirred at 60 °C for 4 h. The resulting sample was then rinsed with water and finally dried at 85 °C to obtain a stainless steel mesh deposited with polydopamine.

[0071] (3) The stainless steel mesh with polydopamine deposited in step (2) was immersed in a 0.02M CuCl2 solution and stirred at 25 °C for 1.5 h (300 rpm). Then, an aqueous solution of NaBH4 was added to a final concentration of 0.06M, and the mixture was stirred for 2 h to completely reduce the copper ions bound to the polydopamine coating. Finally, the modified stainless steel mesh was removed, cleaned, and dried to a constant weight to obtain a stainless steel mesh with a polydopamine / copper nanocluster coating.

[0072] (4) Repeat steps (2) to (3) on the stainless steel mesh obtained in step (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanoclusters deposited on it.

[0073] (5) Place the stainless steel mesh obtained in step (4) into a solution with a concentration of 0.2 g·L⁻¹. -1 The material was modified in a sodium octadecyl dithiocarbamate solution for 5 h. Then, it was removed and air-dried to obtain a stainless steel mesh with a surface deposited with a double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating, thus preparing the oil-water separation material. Figure 7 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in this embodiment.

[0074] Example 5: This example provides a method for preparing an oil-water separation material, including the following steps:

[0075] (1) Select a stainless steel mesh with an 800-mesh sieve and ultrasonically clean it for 15 minutes in sequence with ethanol, acetone and deionized water to remove surface contaminants. Then, let it air dry at room temperature.

[0076] (2) Dopamine hydrochloride was dissolved in a buffer solution prepared with Tris-HCl at pH 8.5 to obtain a concentration of 2 g·L⁻¹. −1 Dopamine hydrochloride solution;

[0077] The cleaned stainless steel mesh from step (1) was placed in the prepared dopamine hydrochloride solution and stirred at 25 °C for 24 h. Subsequently, the resulting sample was rinsed with water and finally dried at 85 °C to obtain a stainless steel mesh with polydopamine deposited on it.

[0078] (3) The stainless steel mesh with polydopamine deposited in step (2) was immersed in a CuCl2 solution with a concentration of 0.08 M and stirred at 25 °C for 0.5 h (300 rpm). Then, an aqueous solution of NaBH4 was added, with a final NaBH4 concentration of 0.05 M, and the mixture was stirred for 2 h to completely reduce the copper ions bound to the polydopamine coating. Finally, the modified stainless steel mesh was removed, cleaned, and dried to a constant weight to obtain a stainless steel mesh with polydopamine / copper nanoclusters deposited on it.

[0079] (4) Repeat steps (2) to (3) to obtain a stainless steel mesh with a double layer of polydopamine / copper nanocluster coating deposited on the surface.

[0080] (5) Place the stainless steel mesh obtained in step (4) into a solution with a concentration of 0.4 g·L⁻¹. -1 The material was modified in a sodium octadecyl dithiocarbamate solution for 4 h. Then, it was removed and air-dried to obtain a stainless steel mesh with a surface deposited with a double layer of polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating, thus preparing the oil-water separation material. Figure 8 This is a measurement diagram of the water contact angle of the oil-water separation material prepared in this embodiment.

[0081] Oil-water separation tests were conducted on the oil-water separation materials prepared in Examples 1-5. The test results showed that the separation efficiency of the oil-water separation materials prepared in each example reached more than 90%. Moreover, after the oil-water separation process can be repeated 40 times, it can still maintain excellent hydrophobicity (contact angle >151°) and high efficiency (more than 96.2%).

[0082] like Figure 4 As shown, filtration experiments with different oil-water mixtures were conducted to evaluate the filtration capacity of the superhydrophobic stainless steel mesh. The separation efficiency of a mixture of deionized water and three test oils (kerosene, chloroform, and hexane) at a volume ratio of 3:1 exceeded 97.6%.

[0083] The oil-water separation material prepared by this invention is a modified octadecylamine-modified metal mesh superhydrophobic material. The preparation process is simple and the production cost is low. It exhibits good mechanical stability and resistance to organic solvents, salt solutions, and acid / alkali solutions. The resulting modified stainless steel mesh demonstrates excellent superhydrophobicity (contact angle >151°) and high separation efficiency (>96.2%). The resistance to organic solvents is related to the material's hydrophobicity and chemical stability, ensuring that it is not dissolved or degraded during oil-water separation. The resistance to salt solutions helps maintain separation efficiency in seawater or saltwater environments. The resistance to acid / alkali solutions reflects the material's chemical stability under extreme pH conditions, ensuring its effectiveness in various industrial applications.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are still covered within the protection scope of the present invention.

Claims

1. A method for producing an oil-water separation material, characterized by, The method comprises the following steps: (1) pretreating the stainless steel mesh; (2) placing the pretreated stainless steel mesh into a weakly alkaline dopamine hydrochloride solution, stirring at a suitable temperature, and washing and drying to obtain a stainless steel mesh with polydopamine deposited on the surface; (3) immersing the stainless steel mesh with polydopamine deposited on the surface obtained in step (2) into a CuCl2 solution, stirring at room temperature, then adding an NaBH4 aqueous solution to stir, and cleaning, airing and drying to constant weight to obtain a stainless steel mesh with polydopamine / copper nanoclusters deposited on the surface; (4) repeating steps (2) and (3) to obtain a stainless steel mesh with double-layer polydopamine / copper nanoclusters deposited on the surface; (5) placing the stainless steel mesh obtained in step (4) into a sodium octadecyl dithiocarbamate solution for modification, taking out and naturally airing after modification, and obtaining a stainless steel mesh with double-layer polydopamine / copper nanoclusters and a sodium octadecyl dithiocarbamate coating deposited on the surface, namely the oil-water separation material; In step (2), the weakly alkaline dopamine hydrochloride solution is prepared by dissolving dopamine hydrochloride in a Tris-HCl buffer solution; The pH of the prepared weak alkaline dopamine hydrochloride solution is 7-8.8; and the concentration of the weak alkaline dopamine hydrochloride solution is 1-4 g·L -1 ; In step (5), the sodium octadecyl dithiocarbamate solution is prepared as follows: 0.001-0.01 mol of octadecylamine and 0.001-0.01 mol of sodium hydroxide are dissolved in 85 mL of ether to obtain a suspension, 0.02-0.2 mol of carbon disulfide is added to the suspension to obtain a mixed solution, the mixed solution is stirred at a speed of 400-500 rpm at room temperature for 0.5-2 h, and the obtained white solid product is collected and dried to obtain sodium octadecyl dithiocarbamate; The prepared sodium octadecyl dithiocarbamate is dispersed in ethanol to prepare a sodium octadecyl dithiocarbamate solution.

2. The method of claim 1, wherein the oil-water separation material is prepared by the steps of: In step (1), a stainless steel mesh with a mesh size of 600-1000 mesh is selected, and the stainless steel mesh is ultrasonically treated with ethanol, acetone and deionized water in sequence, and then is naturally aired at room temperature after ultrasonic treatment.

3. The method of claim 1, wherein the oil-water separation material is prepared by the steps of: In step (2), the stirring temperature is 20-60 ℃, and the stirring time is 4-24 h.

4. The method of claim 1, wherein the oil-water separation material is prepared by the steps of: In step (3), the concentration of the CuCl2 solution is 0.02-0.1 mol / L, and the concentration of the NaBH4 aqueous solution is 0.04-0.08 mol / L; The stirring time in the CuCl2 solution is 0.5-1.5 h, and the stirring time in the NaBH4 aqueous solution is 1-3 h.

5. The method of claim 1, wherein the oil-water separation material is prepared by the steps of: The concentration of the sodium octadecyldithiocarbamate solution in the step (5) is 0.15-0.45 g·L -1 , and the modification time is 2-6 h.

6. An oil-water separation material prepared by the method of any one of claims 1-5, characterized in that, The oil-water separation material has a stainless steel mesh as a substrate, a double-layer polydopamine / copper nanocluster as an intermediate layer, and sodium octadecyl dithiocarbamate as a superhydrophobic modifier.

7. Use of the oil-water separation material according to claim 6, characterized in that The oil-water separation material is used for oil-containing wastewater separation.

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