Universal oil-water separation material and preparation method thereof

Abstract

The invention relates to a composite material, in particular to a universal oil-water separation material and a preparation method thereof. According to the preparation method, the surface of the stainless steel mesh is oxidized and corroded by using a mixed solution of ammonium persulfate and sodium hydroxide, and then the oxidized and corroded surface of the stainless steel mesh reacts with oxalic acid, so that the surface of the prepared stainless steel mesh material contains a large number of polar groups; and finally, the stainless steel mesh treated by oxalic acid is soaked in a buffer solution containing dopamine, dopamine is self-assembled to the surface of the stainless steel mesh in the solution polymerization process, and a super-hydrophilic layer is formed. The preparation method is simple and easy to implement; the prepared universal oil-water separation material can be applied to various oil-water separation occasions, and can be used for separating edible oil / water mixtures, petroleum crude oil / water mixtures, mixed organic solvent / water mixtures and the like with complex components.

Description

Technical Field

[0001] The invention relates to a composite material, in particular to a universal oil-water separation material and a preparation method thereof. Background Art

[0002] The most common and widely used method for oil-water separation is membrane separation. The preparation of membrane materials with super-hydrophilic structures can not only allow dense water to pass quickly, but its super-hydrophilic surface can also combine with water molecules to form a hydration layer and reduce the adsorption of oil and organic solvents, which gives the super-hydrophilic film surface good anti-pollution and self-cleaning capabilities. Although scientific researchers have done a lot of research on super-hydrophilic materials, super-hydrophilic materials are currently subject to many limitations in the separation and treatment of oily wastewater. For example, most of the super-hydrophilic materials currently prepared can only quickly separate a limited number of oil-water mixtures.

[0003] In addition, for oil-water mixtures in real life, industrial production, and accident sites such as oil extraction, most of these oils have complex components. Current hydrophilic materials are still difficult to use to separate oil-water mixtures containing multiple components. Summary of the invention

[0004] In order to solve the problem that the oil-water separation material in the prior art is inconvenient to separate the oil-water mixture with complex components, the present invention provides a universal oil-water separation material and a preparation method thereof.

[0005] The first aspect of the present invention provides a method for preparing a universal oil-water separation material, which comprises the following steps:

[0006] The stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate;

[0007] Taking out the stainless steel mesh and soaking it in an oxalic acid solution to obtain a stainless steel mesh oil-water separation material;

[0008] The stainless steel mesh oil-water separation material is immersed in a tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution containing dopamine to obtain a universal oil-water separation material;

[0009] Among them, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass concentration of sodium hydroxide is 3% to 20%, and the mass concentration of ammonium persulfate is 1% to 6%; the mass concentration of the oxalic acid solution is 0.2% to 5%; in the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine, the mass concentration of dopamine is 0.5% to 4%.

[0010] The second aspect of the present invention provides a universal oil-water separation material, which is obtained by the preparation method of the universal oil-water separation material.

[0011] The third aspect of the present invention provides the use of the universal oil-water separation material in oil-water separation.

[0012] A fourth aspect of the present invention provides an oil-water separation method, which comprises the following steps:

[0013] Placing the oil-water mixture on one side of the universal oil-water separation material;

[0014] The water in the oil-water mixture is made to pass through the universal oil-water separation material under the action of a driving force.

[0015] The technical solution of the embodiment of the present invention has the following beneficial effects:

[0016] (1) The stainless steel mesh is treated with a mixed solution containing sodium hydroxide and ammonium persulfate, an oxalic acid solution, and a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine in sequence, so that polydopamine is coated on the stainless steel surface, thereby enhancing the ability of the universal oil-water separation material to separate complex oil-water mixtures;

[0017] (2) Universal oil-water separation materials can quickly and efficiently separate different types of oily wastewater such as kitchen oil, industrial oil, organic solvents, etc., with a separation efficiency of more than 99% and a separation flux of 10 4 ~10 5 Liters per square meter per hour; the universal oil-water separation material can also separate the mixture of mixed edible oil, petroleum crude oil, mixed organic solvent and water;

[0018] (3) The universal oil-water separation material has a wide range of oil-water separation effects and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a scanning electron microscope photo of the untreated stainless steel mesh surface.

[0020] Figure 2 This is a scanning electron microscope photograph of the surface of a stainless steel mesh after oxidation corrosion by a mixed solution containing sodium hydroxide and ammonium persulfate.

[0021] Figure 3 This is a scanning electron microscope photograph of the surface of the stainless steel mesh oil-water separation material in Example 1 of the present invention.

[0022] Figure 4 This is a scanning electron microscope photograph of the surface of the universal oil-water separation material in Example 3 of the present invention.

[0023] Figure 5 This is a scanning electron microscope photograph of the cross section of the universal oil-water separation material in Example 3 of the present invention.

[0024] Figure 6This is the element distribution diagram on the surface of the universal oil-water separation material according to Example 3 of the present invention.

[0025] Figure 7 These are Raman spectra of the stainless steel mesh oil-water separation material of Example 1 of the present invention, the universal oil-water separation material of Example 3, and the untreated stainless steel mesh.

[0026] Figure 8 Surface energy spectrum analysis diagrams of the stainless steel mesh oil-water separation material of Example 1 and the universal oil-water separation material of Example 3 of the present invention.

[0027] Fig. 9 These are underwater oil contact angle photographs and contact angle data diagrams of the universal oil-water separation materials of Examples 7 to 11 of the present invention.

[0028] Fig.10 This is a photo of a separator used in an embodiment of the present invention.

[0029] Fig.11 This is a diagram showing the oil-water separation results of Examples 12 to 20 of the present invention.

[0030] Fig.12 This is a diagram of the oil-water separation results of Examples 21 to 25 of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] The first aspect of the present invention provides a method for preparing a universal oil-water separation material, which comprises the following steps:

[0033] The stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate;

[0034] Taking out the stainless steel mesh and soaking it in an oxalic acid solution to obtain a stainless steel mesh oil-water separation material;

[0035] The stainless steel mesh oil-water separation material is immersed in a tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution containing dopamine to obtain a universal oil-water separation material;

[0036] Among them, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass concentration of sodium hydroxide is 10% to 15%, and the mass concentration of ammonium persulfate is 4% to 8%; the mass concentration of the oxalic acid solution is 0.5% to 4%; in the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine, the mass concentration of dopamine is 0.5% to 4%.

[0037] In the specific operation, sodium hydroxide and ammonium persulfate can be dissolved in a solvent, and then the stainless steel mesh is fully immersed in a mixed solution containing sodium hydroxide and ammonium persulfate for etching; after etching, the etched stainless steel mesh is immersed in an oxalic acid solution for treatment, and then dried to obtain a stainless steel mesh oil-water separation material; the stainless steel mesh oil-water separation material is self-assembled in a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine, and repeatedly rinsed with deionized water and dried to obtain a universal oil-water separation material. After the stainless steel mesh is oxidatively etched with ammonium persulfate / sodium hydroxide, it is treated with oxalic acid to increase the polar groups and hydrophilicity of the stainless steel mesh surface; dopamine is then polymerized and assembled on the surface of the stainless steel mesh containing a large number of polar groups by relying on electrostatic force and capillary action. The composite material after assembly has super hydrophilicity, which can not only quickly separate different types of oily wastewater, but also efficiently separate oil-water mixtures containing complex components.

[0038] In some embodiments, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass ratio of sodium hydroxide to ammonium persulfate is 80:20 to 60:40. Preferably, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass ratio of sodium hydroxide to ammonium persulfate is 2:1.

[0039] In some embodiments, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass concentration of sodium hydroxide is 12%, and the mass concentration of ammonium persulfate is 6%.

[0040] In some embodiments, the mass concentration of the oxalic acid solution is 1% to 3%. Preferably, the mass concentration of the oxalic acid solution is 2%.

[0041] In some embodiments, in the tris-hydrochloric acid buffer solution containing dopamine, the mass concentration of dopamine is 1% to 2%.

[0042] In some embodiments, in the Tris-HCl buffer solution containing dopamine, the pH of the Tris-HCl buffer solution is in the range of 7 to 10. Preferably, in the Tris-HCl buffer solution containing dopamine, the pH of the Tris-HCl buffer solution is 8.

[0043] In some embodiments, the pore size of the stainless steel mesh is 600-3000 mesh. Preferably, the pore size of the stainless steel mesh is 1000-2000 mesh.

[0044] In some embodiments, the stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate at 20 to 70° C. for 10 to 60 hours. Preferably, the stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate at 45° C. for 36 hours.

[0045] In some embodiments, the stainless steel mesh is taken out and soaked in an oxalic acid solution at 20-60° C. for 0.25-6 hours. Preferably, the stainless steel mesh is taken out and soaked in an oxalic acid solution at 20° C. for 0.5 hours.

[0046] In some embodiments, the stainless steel mesh oil-water separation material is immersed in a tris-hydrochloric acid buffer solution containing dopamine at 20-60° C. for 4-50 hours. Preferably, the stainless steel mesh oil-water separation material is immersed in a tris-hydrochloric acid buffer solution containing dopamine at 20-40° C. for 5-10 hours.

[0047] In some embodiments, the stainless steel mesh, sodium hydroxide, ammonium persulfate, oxalic acid, dopamine, and tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution are industrial grade or non-industrial grade products, preferably industrial grade products.

[0048] It should be noted that the stainless steel mesh, sodium hydroxide, ammonium persulfate, oxalic acid, dopamine, and tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution are commonly used materials in the art and are not particularly limited.

[0049] A second aspect of the present invention provides a universal oil-water separation material, which is obtained by the preparation method of the universal oil-water separation material.

[0050] The third aspect of the present invention provides the use of the universal oil-water separation material in oil-water separation.

[0051] A fourth aspect of the present invention provides an oil-water separation method, which comprises the following steps:

[0052] Placing the oil-water mixture on one side of the universal oil-water separation material;

[0053] The water in the oil-water mixture is made to pass through the universal oil-water separation material under the action of a driving force.

[0054] In some embodiments, the oil in the oil-water mixture is one or more of toluene, petroleum ether, n-hexane, refrigeration oil, paraffin oil, lubricating oil, rapeseed oil, soybean oil, olive oil, corn oil, peanut oil, and crude oil. Preferably, the oil in the oil-water mixture is at least three of toluene, petroleum ether, n-hexane, refrigeration oil, paraffin oil, lubricating oil, rapeseed oil, soybean oil, olive oil, corn oil, peanut oil, and crude oil. For example, the oil in the oil-water mixture is a mixed oil formed by rapeseed oil, soybean oil, corn oil, peanut oil, and olive oil, or the oil in the oil-water mixture is a mixed oil formed by toluene, n-hexane, and petroleum ether.

[0055] In some embodiments, the driving force is gravity or pressure. For example, an oil-water mixture is placed on the universal oil-water separation material, so that the water in the oil-water mixture passes through the universal oil-water separation material under the action of the oil-water mixture's own gravity. For another example, an oil-water mixture is placed on one side of the universal oil-water separation material, and pressure is applied to the oil-water mixture, so that the water in the oil-water mixture passes through the universal oil-water separation material.

[0056] Some typical embodiments are described below. In the following embodiments, the raw materials used are all commercially available products.

[0057] Example 1

[0058] Fully dissolve 12g of sodium hydroxide and 6g of ammonium persulfate in 82g of water to obtain a mixed solution containing sodium hydroxide and ammonium persulfate; immerse a stainless steel mesh with a pore size of 1000 mesh in the mixed solution for etching at a temperature of 45°C for 36h to obtain a stainless steel mesh with an etched surface; fully dissolve 2g of oxalic acid in 98g of water, and immerse the etched stainless steel mesh in the oxalic acid solution at a temperature of 45°C for 0.5h to obtain a stainless steel mesh oil-water separation material.

[0059] Embodiment 2 to Embodiment 6

[0060] 12g of sodium hydroxide and 6g of ammonium persulfate are fully dissolved in 82g of water to obtain a mixed solution containing sodium hydroxide and ammonium persulfate; a stainless steel mesh with a pore size of 1000 mesh is immersed in the mixed solution for etching at a temperature of 45°C for 36h to obtain an etched stainless steel mesh; 2g of oxalic acid is fully dissolved in 98g of water, and the etched stainless steel mesh is immersed in the oxalic acid solution at a temperature of 45°C for 0.5h to obtain a stainless steel mesh oil-water separation material; 0.4g of dopamine is dissolved in 40mL of tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution (Aladdin Industrial Products), the pH is adjusted to between 8-9, and a stainless steel mesh oil-water separation material with a size of 2cm×2cm is immersed in a tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution containing dopamine at 45°C for 6 hours to obtain a polydopamine-coated stainless steel mesh composite material, i.e., a universal oil-water separation material.

[0061] By changing the dosage of dopamine, different embodiments are obtained, and the specific parameters are listed in Table 1.

[0062] Table 1 Dosage of dopamine and soaking time

[0063] Sample name Dopamine (g) Tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution (mL) Soaking time (h) Example 1 0 0 0 Example 2 0.2 40 6 Example 3 0.4 40 6 Example 4 0.8 40 6 Example 5 1.2 40 6 Example 6 1.6 40 6

[0064] The surface of the untreated stainless steel mesh, the etched stainless steel mesh, the stainless steel mesh oil-water separation material obtained in Example 1, and the universal oil-water separation material obtained in Example 3 were analyzed using a scanning electron microscope (SEM). The results showed that the surface of the untreated stainless steel mesh was relatively smooth overall (see Figure 1 ); After being etched by a mixed solution containing sodium hydroxide and ammonium persulfate, the stainless steel surface has a large number of upright or flat petal-like structures (see Figure 2 ); In the SEM image of the stainless steel mesh oil-water separation material in Example 1, the petal-like structure disappears, and there are a large number of uneven block structures on the surface (see Figure 3 ); In the SEM image of the universal oil-water separation material in Example 3, the block structure disappears and the surface becomes a continuous undulating structure (see Figure 4 By analyzing the cross section of the universal oil-water separation material in Example 3, it can be found that the thickness of the dopamine loaded on the stainless steel surface is about 500 nanometers (see Figure 5 ).

[0065] The surface element analysis of the universal oil-water separation material prepared in Example 3 showed that carbon, oxygen and nitrogen elements were evenly distributed, indicating that polydopamine was successfully and evenly loaded on the surface of the stainless steel mesh (see Figure 6 ).

[0066] As the concentration of dopamine gradually increased, the thickness of polydopamine loaded on the surface of the stainless steel mesh tended to increase.

[0067] Raman spectroscopy was used to characterize the untreated stainless steel mesh, the stainless steel mesh oil-water separation material obtained in Example 1, and the universal oil-water separation material obtained in Example 3. The test results are as follows: Figure 7 As shown. In the Raman spectrum, the -1 、1402cm -1 、1208cm -1 、979cm -1 The signals at correspond to the stretching vibration of the imine group (C=N) in the pyrrole ring, the stretching vibration of the phenolic hydroxyl group, and the carbon-carbon single bond ( C–C =C), bending vibration, CC single-cell rocking vibration, these signal peaks are from the polydopamine on the surface of the stainless steel mesh in Example 3. However, these signals were not observed in the Raman spectra of the untreated stainless steel mesh and the stainless steel mesh oil-water separation material in Example 1. This shows that polydopamine was successfully loaded on the surface of the stainless steel mesh in Example 3.

[0068] X-ray photoelectron spectroscopy (XPS) analysis was performed on the stainless steel mesh oil-water separation material obtained in Example 1 and the universal oil-water separation material obtained in Example 3. The results are shown in Figure 8 In the energy spectrum of the stainless steel mesh oil-water separation material in Example 1, there are strong energy spectrum signals of C and O, indicating that a large number of polar groups are formed on the surface of the stainless steel mesh. In the energy spectrum of the universal oil-water separation material in Example 3, in addition to the energy spectrum signals of C and O, there are also energy spectrum signals of N and Cl, which indicates that polydopamine is successfully loaded on the surface of the stainless steel mesh.

[0069] Embodiment 7 to Embodiment 11

[0070] The universal oil-water separation material prepared in Example 3 was immersed in different environmental conditions for a period of time. The different environmental conditions and treatment times are listed in Table 2.

[0071] Table 2 Different environmental treatment conditions

[0072] Sample name Example 7 Example 8 Example 9 Example 10 Embodiment 11 Treatment solution Tap water 5% NaCl 0.1M HCl 0.1M NaOH Ultrasound Processing time 48h 48h 48h 48h 30min

[0073] The oil-water separation materials treated in Examples 7 to 11 were subjected to underwater oil contact angle analysis. The results are shown in Fig. 9. After being treated in tap water for 48 hours, the underwater oil contact angle of the universal oil-water separation material of Example 7 was 159.1°; after being treated in 5% NaCl for 48 hours, the underwater oil contact angle of the universal oil-water separation material of Example 8 was 161.0°; after being treated with 0.1M HCl for 48 hours, the underwater oil contact angle of the universal oil-water separation material of Example 9 was 159.9°; after being treated with 0.1M NaCl for 48 hours, the underwater oil contact angle of the universal oil-water separation material of Example 10 was 153.4°; after being treated with ultrasound for 30 minutes, the underwater oil contact angle of the universal oil-water separation material of Example 11 was 147.2°. This shows that the oil-water separation material prepared in Example 3 of the present invention has strong resistance to acid, alkali and salt corrosion.

[0074] Example 12 to Example 20

[0075] The universal oil-water separation material prepared in Example 3 was cut into blocks of 2 cm × 2 cm in size, and an oil-water separation experiment was performed. First, corn oil was mixed with water in a ratio of 1:9 to obtain an oil-water mixture; the universal oil-water separation material prepared in Example 3 was used as a separation membrane and installed on a separator. The structure of the separator is as follows: Fig.10 100 mL of oil-water mixture was poured into the separator from the top to perform the oil-water separation experiment. The water flux was calculated using formula 1, and the oil-water separation efficiency was calculated using formula 2.

[0076] Separation flux (Flux) = V / St(1)

[0077] Among them, V represents the volume of water passing through the separator, in liters; S represents the effective cross-sectional area of ​​the oil-water separation material during the separation process, in square meters; t represents the time of oil-water separation, in hours.

[0078] Separation efficiency (SE) % = (1-C f / C 0 )(2)

[0079] Among them, C f Indicates the weight of the oil after separation, C 0 Indicates the weight of the oil before separation.

[0080] The above separation experiment was repeated 10 times, and the average separation flux and separation efficiency were calculated.

[0081] By changing different types of oil for separation experiments, a series of different separation flux and separation efficiency data can be obtained, and the specific parameters are shown in Table 3.

[0082] Table 3 Specific parameters of different oil-water mixtures

[0083] Example Oil Type Oil dosage (mL) Water consumption (mL) Example 12 Corn Oil 10 90 Example 13 lubricating oil 10 90 Embodiment 14 Peanut Oil 10 90 Embodiment 15 olive oil 10 90 Example 16 Paraffin oil 10 90 Embodiment 17 Petroleum ether 10 90 Embodiment 18 n-Hexane 10 90 Embodiment 19 Refrigeration oil 10 90 Embodiment 20 Petroleum Crude Oil 10 90

[0084] like Fig.11 As shown in the figure, the separation results show that the separation flux of all oils is between 10 4 ~10 5 When separating a mixture of n-hexane and water, the maximum water flux can reach 1.7×10 5 Liters per square hour. The average separation flux of crude oil also reaches 3.5×10 4 Liter per square hour. Except for the large fluctuation of separation efficiency of crude oil (99%-95%), the separation efficiency of most oils fluctuates very little and is higher than 99.5%.

[0085] Example 21 to Example 23

[0086] The universal oil-water separation material prepared in Example 3 was cut into blocks of 2 cm × 2 cm in size for oil-water separation experiments. First, rapeseed oil was mixed with water in a ratio of 5:5 to obtain an oil-water mixture; the universal oil-water separation material prepared in Example 3 was used as a separation membrane and installed on a separator. 100 mL of the oil-water mixture was poured from the upper end of the separator for an oil-water separation experiment, and the water flux was calculated using Formula 1, and the oil-water separation efficiency was calculated using Formula 2.

[0087] The above separation experiment was repeated 10 times, and the average separation flux and separation efficiency were calculated.

[0088] By changing different types of oil for separation experiments, a series of different separation flux and separation efficiency data can be obtained, and the specific parameters are shown in Table 4.

[0089] Embodiment 24

[0090] The universal oil-water separation material prepared in Example 3 was cut into blocks of 2cm×2cm in size for oil-water separation experiments. First, rapeseed oil, soybean oil, corn oil, peanut oil, and olive oil were mixed in equal volumes to obtain a mixed oil; the mixed oil was then blended with water in a ratio of 5:5 to obtain a mixed oil / water mixture; the universal oil-water separation material prepared in Example 3 was used as a separation membrane and installed on a separator. 100mL of the mixed oil-water mixture was poured from the upper end of the separator for an oil-water separation experiment, and the water flux was calculated using Formula 1, and the oil-water separation efficiency was calculated using Formula 2.

[0091] The above separation experiment was repeated 10 times, and the average separation flux and separation efficiency were calculated.

[0092] Embodiment 25

[0093] The universal oil-water separation material prepared in Example 3 was cut into blocks of 2 cm × 2 cm in size for oil-water separation experiments. First, equal volumes of toluene, n-hexane, and petroleum ether were mixed evenly to obtain a mixed solvent, and then the mixed solvent was blended with water in a ratio of 5:5 to obtain a mixture of a mixed solvent and water; the universal oil-water separation material prepared in Example 3 was used as a separation membrane and installed on a separator. 100 mL of the mixed solvent / water mixture was poured from the upper end of the separator for an oil-water separation experiment, and the water flux was calculated using Formula 1, and the oil-water separation efficiency was calculated using Formula 2.

[0094] The above separation experiment was repeated 10 times, and the average separation flux and separation efficiency were calculated.

[0095] The specific parameters of different types of oil-water separation experiments in Examples 21 to 25 are shown in Table 4.

[0096] Table 4 Specific parameters of different oil-water mixtures

[0097] Example Oil Type Oil dosage (mL) Water consumption (mL) Embodiment 21 Rapeseed Oil 50 50 Embodiment 22 Soybean Oil 50 50 Embodiment 23 Toluene 50 50 Embodiment 24 Mixed oil 50 50 Embodiment 25 Mixed solvents 50 50

[0098] like Fig.12 As shown in the results, the separation flux of all oils in Examples 21 to 25 is between 8.0×10 4 ~1.6×10 5 When separating a mixture of mixed solvent and water, the maximum water flux can reach 1.5×10 5 Liters per square hour; the average separation flux of water in the mixture of mixed oil and water also reaches 9.0×10 4 Liter per square hour. The separation efficiency of all embodiments is higher than 99.5%, and the separation efficiency remains basically stable.

[0099] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a universal oil-water separation material, characterized in that: The following steps are involved: The stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate; Taking out the stainless steel mesh and soaking it in an oxalic acid solution to obtain a stainless steel mesh oil-water separation material; The stainless steel mesh oil-water separation material is immersed in a tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution containing dopamine to obtain a universal oil-water separation material; Among them, in the mixed solution containing sodium hydroxide and ammonium persulfate, the mass concentration of sodium hydroxide is 10% to 15%, and the mass concentration of ammonium persulfate is 4% to 8%; the mass concentration of the oxalic acid solution is 0.5% to 4%; in the tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine, the mass concentration of dopamine is 0.5% to 4%.

2. The method according to claim 1, characterized in that In the tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution containing dopamine, the mass concentration of dopamine is 1% to 2%.

3. The method according to claim 1, characterized in that In the Tris-hydrochloric acid buffer solution containing dopamine, the pH range of the Tris-hydrochloric acid buffer solution is 7-10.

4. The method according to claim 1, characterized in that: The stainless steel mesh is immersed in a mixed solution containing sodium hydroxide and ammonium persulfate at 20-70°C for 10-60 hours.

5. The method according to claim 1, characterized in that The stainless steel mesh is taken out and immersed in an oxalic acid solution at 20 to 60° C. for 0.25 to 6 hours.

6. The method according to claim 1, characterized in that The stainless steel mesh oil-water separation material is immersed in a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution containing dopamine at 20-60° C. for 4-50 hours.

7. A universal oil-water separation material, characterized in that: The universal oil-water separation material is obtained by the preparation method of any one of claims 1 to 6.

8. Use of the universal oil-water separation material according to claim 7 in oil-water separation.

9. An oil-water separation method, characterized in that: The following steps are involved: Placing the oil-water mixture on one side of the universal oil-water separation material according to claim 7; The water in the oil-water mixture is made to pass through the universal oil-water separation material under the action of a driving force.

10. The method according to claim 9, characterized in that The oil in the oil-water mixture is one or more of toluene, petroleum ether, n-hexane, refrigeration oil, paraffin oil, lubricating oil, rapeseed oil, soybean oil, olive oil, corn oil, peanut oil, and crude petroleum.

Images