Preparation method and application of pH-response-controllable oil-water separation material

Abstract

The invention discloses a preparation method and application of a pH-responsive controllable oil-water separation material, polyurethane sponge is used as a substrate, polypyrrole is attached to the sponge substrate through an in-situ polymerization method, a pH-responsive polymer is introduced into the sponge substrate through a soaking method, and finally the pH-responsive controllable oil-water separation material is obtained. The controllability of the material in the oil-water separation process is reflected as follows: due to the introduction of the pH responsive polymer, the surface of the material has pH responsiveness, the surface of the material has different wettability by adjusting the pH value, different types of oil-water mixtures can be controllably separated in a targeted manner, and the adsorption and desorption of oil products can be realized. Due to the introduction of polypyrrole, the material has good photo-thermal conversion capacity, the viscosity of crude oil can be effectively reduced, and the absorption rate of the crude oil can be improved. The material with pH responsiveness has wide application prospects in the fields of oil-water separation, oil product adsorption and desorption and crude oil absorption.

Description

Technical Field

[0001] The present invention belongs to the field of pH responsive material preparation, and specifically relates to a preparation method of a pH responsive controllable oil-water separation material and its application in oil adsorption and desorption. Background Art

[0002] With the rapid development of the global economy and petrochemical industry, a series of water pollution problems have caused serious impacts on the ecological environment and people's daily lives. For example, the oil spills from the French tanker "Erica" ​​and the Bahamian tanker "Prestige" have caused great harm to local fisheries and coastal ecosystems. Various traditional separation and adsorption materials such as organic polymers, expanded graphite, activated carbon, foam, etc. are used to treat oil spills. However, low separation efficiency, low absorption capacity and poor recyclability remain urgent problems for the purification of oily wastewater and the adsorption and desorption of oil products. Therefore, there is an urgent need to develop a wettable material with a simple preparation process, excellent separation performance, good adsorption performance and applicability in a variety of environments.

[0003] Many researchers have developed numerous wettable materials with remarkable separation performance, but they still face challenges such as limited wettability, easy contamination, and poor stability. In recent years, pH-responsive special wettable materials have garnered significant interest. For example, Chen et al. [Chen Q, Liu J, Tang L, et al. Journal of Environmental Chemical Engineering, 2024, 12:112422.] attached pH-responsive nanoparticles to various substrates via a simple impregnation method, creating pH-responsive smart composite materials for multifunctional oil-water separation and efficient recovery. However, this material exhibited a low adsorption rate for high-viscosity crude oil and poor mechanical properties, hindering long-term use. Gan et al. [Gan S, Li H, Zhu X, et al. Advanced Functional Materials, 2023, 33:2305975.] constructed an expandable membrane that modulates surface wettability by electrolytically inducing interfacial pH. This membrane not only achieves a patterned superwetting surface but also controls the flux of aqueous solutions, resulting in excellent separation performance for oil-water mixtures. However, the membrane is not very reusable during use and has some defects in mechanical properties. In addition, electrolysis induction will cause certain energy consumption, which will affect its actual application range in oil and water treatment. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a pH-responsive controllable oil-water separation material. The preparation method is simple and easy, the raw materials are widely available and inexpensive, the material has good separation performance for different types of oil-water mixtures, and has good adsorption and desorption performance for different oil products. It also has excellent photothermal conversion ability, can effectively reduce crude oil viscosity and increase its absorption rate.

[0005] In response to the above problems, the present invention adopts a polymer with pH responsiveness, which is grafted onto the original sponge after in-situ polymerization of pyrrole by immersion method, and finally obtains a controllable oil-water separation material with pH response. The introduction of the pH responsive polymer makes the original sponge pH responsive, and different types of oil-water mixtures can be efficiently separated by adjusting the pH value. When the pH is ≥ 7, heavy oil-water mixtures can be separated, and when the pH is < 7, light oil-water mixtures can be separated. The introduction of polypyrrole gives the material a good photothermal conversion ability, which can effectively reduce the viscosity of crude oil and increase its absorption rate. The pH responsive controllable oil-water separation material can achieve adsorption and desorption of different oils by adjusting the pH value, and has excellent pH response performance. At the same time, the material also has a good photothermal conversion ability, which can effectively reduce the viscosity of crude oil and increase its absorption rate. It has broad application prospects in the fields of oil-water separation, adsorption and desorption, and crude oil absorption.

[0006] The present invention proposes a preparation and application of a pH-responsive and controllable oil-water separation material, and the technical solution adopted is as follows:

[0007] A method for preparing a pH-responsive controllable oil-water separation material, wherein pyrrole and a pH-responsive polymer are attached to an original sponge by an in-situ polymerization method and an immersion method, and finally a controllable oil-water separation material with pH response is obtained. The introduction of the pH-responsive polymer enables the original sponge to have a certain pH-responsive performance, and the surface wettability of the material can be changed by adjusting the pH value, thereby achieving the separation of different types of oil-water mixtures and the adsorption and desorption of different oil products. The introduction of polypyrrole enables the material to have a good photothermal conversion ability, which can effectively reduce the viscosity of crude oil and increase its absorption rate. The preparation method of the present invention is simple to operate, has a wide source of raw materials, and is low in price. It has broad application prospects in the separation of industrial oil-water mixtures and the treatment of oily wastewater.

[0008] The specific steps are as follows:

[0009] (1) Stirring the binder polyvinyl alcohol in deionized water to fully dissolve it, adding pyrrole, anhydrous ferric chloride solution and surfactant sodium dodecylbenzene sulfonate after it is fully dissolved, and continuing to stir; then, placing the original sponge cleaned with deionized water and anhydrous ethanol into the above solution, and in situ polymerizing it at 0-30°C for 1-6 hours to obtain a polypyrrole sponge, wherein the mass ratio of pyrrole, oxidant anhydrous ferric chloride, surfactant sodium dodecylbenzene sulfonate and binder polyvinyl alcohol is 10-20:120-160:1:30-60.

[0010] (2) Monomer A, diethylaminoethyl methacrylate, and initiator B are sequentially added to a round-bottom flask, followed by addition of an appropriate amount of solvent C, and the mixture is stirred thoroughly. Atomic free radical polymerization is carried out at 45-75°C under a nitrogen or argon atmosphere for 10-24 hours to obtain a pH-responsive polymer solution, wherein the mass ratio of monomer A, diethylaminoethyl methacrylate, initiator B, and solvent C is 40-130:140-300:1:700-1500.

[0011] (3) Immersing the polypyrrole sponge obtained in (1) into the pH-responsive polymer solution obtained in (2), allowing it to stand for 2-20 minutes, and after complete absorption, placing it in an oven at 20-80°C and drying it for 10-60 minutes, ultimately obtaining a pH-responsive controllable oil-water separation material.

[0012] The monomer A in step (2) is one or more of vinyltriethoxysilane and vinyltrimethoxysilane;

[0013] The initiator B in step (2) is one or more of azobisisobutyronitrile, diacyl peroxide, and potassium persulfate;

[0014] The solvent C in step (2) is one or more of tetrahydrofuran, N,N-dimethylformamide, and N-methylpyrrolidone.

[0015] The invention discloses an application of a preparation method of a pH-responsive controllable oil-water separation material in the separation of different types of oil-water mixtures.

[0016] The invention discloses a method for preparing a pH-responsive controllable oil-water separation material and its application in the adsorption and desorption of different types of oils.

[0017] The invention discloses an application of a preparation method of a pH-responsive controllable oil-water separation material in reducing crude oil viscosity.

[0018] The pH-responsive controllable oil-water separation material prepared by the present invention has the following beneficial effects:

[0019] a. The preparation process of the present invention is simple, the raw materials are widely available, the price is low, and it is easy to mass produce;

[0020] b. The pH-responsive controllable oil-water separation material prepared by in-situ polymerization and immersion method has good mechanical properties;

[0021] c. The pH-responsive controllable oil-water separation material has excellent pH responsiveness and can separate different types of oil-water mixtures;

[0022] d. The pH-responsive controllable oil-water separation material has excellent pH responsiveness and can achieve adsorption and desorption of different oily wastewaters;

[0023] e. The pH-responsive controllable oil-water separation material has a good photothermal effect, which can effectively reduce the viscosity of crude oil and increase its absorption rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following is a further detailed description of the implementation method of the present invention in conjunction with the accompanying drawings.

[0025] Figure 1 Schematic diagram of the preparation of pH-responsive polymers by atomic radical polymerization;

[0026] Figure 2 It is a schematic diagram of the process for preparing a pH-responsive controllable oil-water separation material;

[0027] Figure 3 is the NMR characterization result of the prepared pH-responsive polymer;

[0028] Figure 4 Scanning electron micrographs of the original sponge surface (aa”), the polypyrrole sponge surface (bb”), the pH-responsive controllable oil-water separation material surface (cc”), and the EDS spectrum of the pH-responsive controllable oil-water separation material (dg);

[0029] Figure 5 The pH-responsive controllable oil-water separation material shows (a) the contact angles of water droplets at different pH values ​​in air (at pH = 12, the water contact angle is 150°; at pH = 7, the water contact angle is 133°; at pH = 3, the water contact angle is 34°), (b) the contact angles of oil in air (0°) and underwater (155.5°).

[0030] Figure 6 is the contact angle of the original sponge with water droplets of different pH values ​​in air;

[0031] Figure 7Schematic diagram of pH-responsive controllable oil-water separation material (a) separation of heavy oil-water at pH ≥ 7 and separation of light oil-water at pH < 7, (b) mechanism diagram of separation of heavy oil-water at pH ≥ 7 and separation of light oil-water at pH < 7, (c) separation flux and separation efficiency diagram of ten cycles of separation of heavy oil-water at pH ≥ 7, (d) separation flux and separation efficiency diagram of ten cycles of separation of light oil-water at pH < 7;

[0032] Figure 8 Schematic diagram of the separation of a three-phase mixture of heavy oil, water and light oil by a pH-responsive controllable oil-water separation material;

[0033] Figure 9 Schematic diagram of oil adsorption and desorption by pH-responsive controllable oil-water separation materials: (a) absorbing oil and (b) not releasing oil under alkaline conditions, (c) not absorbing oil and (d) releasing oil under acidic conditions;

[0034] Figure 10 (a) Temperature changes of the pH-responsive controllable oil-water separation material under different sunlight intensity (0.5 sun, 1 sun, 1.5 sun, and 2 suns), and (b) cyclic temperature changes under 1 sun intensity.

[0035] Figure 11 This is the infrared thermal imaging image of the maximum temperature of the pH-responsive controllable oil-water separation material under different sunlight (0.5 suns, 1 sun, 1.5 suns and 2 suns);

[0036] Figure 12 is the temperature change of the pH-responsive controllable oil-water separation material and the original material under 1 sun irradiation;

[0037] Figure 13 The images of crude oil absorbed by the original material under (a) no light source and (b) light source conditions.

[0038] Figure 14 Images of crude oil absorbed by the pH-responsive controllable oil-water separation material (a) without light source and (b) with light source.

[0039] Figure 15 The pH-responsive controllable oil-water separation material simulates the absorption process of offshore crude oil on the water surface under (a) no light source and (b) light source conditions.

[0040] Figure 16 It is the process in which the pH-responsive controllable oil-water separation material absorbs crude oil after pre-irradiation. DETAILED DESCRIPTION

[0041] The present invention is further described below with reference to specific examples, but the protection scope of the present invention is not limited thereto.

[0042] Example 1:

[0043] A preparation method of a pH-responsive controllable oil-water separation material (the preparation process is shown in FIG Figure 2 As shown), comprising the following process steps:

[0044] (1) 0.9 g of binder polyvinyl alcohol (1799 type, alcoholysis degree 98%-99%) was stirred in deionized water to fully dissolve it. After fully dissolved, 0.3 g of pyrrole, 30 mL of anhydrous ferric chloride solution (2.8 g of anhydrous ferric chloride) and 0.02 g of surfactant sodium dodecylbenzene sulfonate were added and stirring was continued. Then, the original sponge cleaned with deionized water and anhydrous ethanol was placed in the above solution and in situ polymerized at 0°C for 2 h to obtain a polypyrrole sponge.

[0045] (2) 2 g of vinyl triethoxysilane was first dissolved in 25 mL of tetrahydrofuran solution, and 0.05 g of initiator azobisisobutyronitrile was added. The reaction was carried out under nitrogen atmosphere at 60 °C for 10 h. Then, 7 g of diethylaminoethyl methacrylate and 15 mL of tetrahydrofuran were added, and the reaction was continued under nitrogen atmosphere for 12 h to obtain a pH-responsive polymer solution (reaction flow diagram shown in FIG. 1 ). Figure 1 shown).

[0046] (3) The polypyrrole sponge obtained in (1) is immersed in the pH-responsive polymer solution obtained in (2), left to stand for 2 minutes, and after complete absorption, placed in an oven at 30°C and dried for 30 minutes, thereby finally obtaining a controllable oil-water separation material with pH responsiveness.

[0047] The NMR characterization results of the pH-responsive copolymers are shown in Figure 2. Figure 3 As shown;

[0048] The scanning electron microscopy image of the prepared pH-responsive controllable oil-water separation material is shown in Figure 4 (cc”);

[0049] The EDS spectrum of the prepared pH-responsive controllable oil-water separation material is shown in Figure 4 (dg) shown;

[0050] The contact angles of the prepared pH-responsive controllable oil-water separation material to droplets of different pH values ​​in air are as follows: Figure 5 (a) (When pH = 12, the water contact angle is 150°, when pH = 7, the water contact angle is 133°, when pH = 3, the water contact angle is 34°.);

[0051] The oil contact angles of the prepared pH-responsive controllable oil-water separation material in air (0°) and underwater (155.5°) are shown in Figure 2. Figure 5 (b)

[0052] The separation effect diagram and separation schematic diagram of the prepared pH-responsive controllable oil-water separation material for heavy oil-water under pH ≥ 7 and for light oil-water under pH < 7 are shown in the figure. Figure 7 (a, b)

[0053] The separation flux and separation efficiency of the prepared pH-responsive controllable oil-water separation material for heavy oil-water separation at pH ≥ 7 and for light oil-water separation at pH < 7 are as follows: Figure 7 (c, d);

[0054] The prepared pH-responsive controllable oil-water separation material has a good separation effect on heavy oil-water-light oil three-phase mixture. Figure 8 As shown;

[0055] The adsorption and desorption of oil products by the prepared pH-responsive controllable oil-water separation material are shown in Figure 2. Figure 9 As shown;

[0056] The temperature changes of the prepared pH-responsive controllable oil-water separation material under different sunlight (0.5 sun, 1 sun, 1.5 sun and 2 sun) are shown in Figure 2. Figure 10 (a)

[0057] The surface temperature change cycle test of the prepared pH-responsive controllable oil-water separation material under 1 sun irradiation is as follows Figure 10 (b)

[0058] The infrared thermal imaging of the prepared pH-responsive controllable oil-water separation material after irradiation with different sunlight (0.5 sun, 1 sun, 1.5 sun and 2 sun) is shown in Figure 2. Figure 11 As shown;

[0059] The temperature changes of the prepared pH-responsive controllable oil-water separation material and the original material under 1 sun irradiation are shown in Figure 2. Figure 12 As shown;

[0060] The images of the prepared raw material absorbing crude oil under (a) no light source and (b) light source are shown in Figure 2. Figure 13 As shown;

[0061] Images of the prepared pH-responsive controllable oil-water separation material absorbing crude oil in (a) the absence of light and (b) the presence of light. Figure 14 As shown;

[0062] The prepared pH-responsive controllable oil-water separation material simulates the absorption process of offshore crude oil on the water surface under (a) no light source and (b) light source conditions. Figure 15 As shown;

[0063] The process of crude oil absorption by the prepared pH-responsive controllable oil-water separation material after pre-illumination is as follows: Figure 16 As shown;

[0064] Example 2:

[0065] A preparation method of a pH-responsive controllable oil-water separation material (the preparation process is shown in FIG Figure 2 As shown), comprising the following process steps:

[0066] (1) 1.2 g of binder polyvinyl alcohol (type 1799, degree of alcoholysis 98%-99%) was stirred in deionized water to fully dissolve it. After fully dissolved, 0.4 g of pyrrole, 50 mL of anhydrous ferric chloride solution (4.5 g of anhydrous ferric chloride) and 0.02 g of a surfactant, sodium dodecylbenzene sulfonate, were added and stirring was continued. Then, the original sponge, which had been cleaned with deionized water and anhydrous ethanol, was placed in the above solution and in situ polymerized at 0°C for 5 h to obtain a polypyrrole sponge.

[0067] (2) 4 g of vinyl triethoxysilane was first dissolved in 35 mL of N,N-dimethylformamide solution, and 0.08 g of initiator potassium persulfate was added. Atomic radical polymerization was carried out at 45 °C under nitrogen atmosphere for 8 h. Then, 14 g of diethylaminoethyl methacrylate and 30 mL of N,N-dimethylformamide were added, and polymerization was continued under nitrogen atmosphere for 10 h to obtain a pH-responsive polymer solution (reaction flow diagram shown in FIG. 1 ). Figure 1 shown).

[0068] (3) The polypyrrole sponge obtained in (1) is immersed in the pH-responsive polymer solution obtained in (2), left to stand for 1 minute, and after complete absorption, placed in an oven at 20°C and dried for 40 minutes, thereby finally obtaining a controllable oil-water separation material with pH responsiveness.

[0069] Example 3:

[0070] A preparation method of a pH-responsive controllable oil-water separation material (the preparation process is shown in FIG Figure 2 As shown), comprising the following process steps:

[0071] (1) 0.9 g of binder polyvinyl alcohol (1799 type, alcoholysis degree 98%-99%) was stirred in deionized water to fully dissolve it. After fully dissolved, 0.3 g of pyrrole, 30 mL of anhydrous ferric chloride solution (2.8 g of anhydrous ferric chloride) and 0.02 g of surfactant sodium dodecylbenzene sulfonate were added and stirring was continued. Then, the original sponge cleaned with deionized water and anhydrous ethanol was placed in the above solution and in situ polymerized at 8°C for 6 h to obtain a polypyrrole sponge.

[0072] (2) 6 g of vinyl trimethoxysilane was first dissolved in 45 mL of N-methylpyrrolidone solution, and 0.06 g of diacyl peroxide was added. The reaction was carried out under nitrogen atmosphere at 50 °C for 12 h. Then, 12 g of diethylaminoethyl methacrylate and 25 mL of N-methylpyrrolidone were added, and the reaction was continued under nitrogen atmosphere for 16 h to obtain a pH-responsive polymer solution (reaction flow diagram shown in FIG). Figure 1 shown).

[0073] (3) The polypyrrole sponge obtained in (1) is immersed in the pH-responsive polymer solution obtained in (2), left to stand for 10 minutes, and after complete absorption, placed in a 50°C oven and dried for 40 minutes, thereby finally obtaining a controllable oil-water separation material with pH responsiveness.

[0074] Example 4:

[0075] A preparation method of a pH-responsive controllable oil-water separation material (the preparation process is shown in FIG Figure 2 As shown), comprising the following process steps:

[0076] (1) 1.5 g of binder polyvinyl alcohol (type 1799, degree of alcoholysis 98%-99%) was stirred in deionized water to fully dissolve it. After fully dissolved, 0.5 g of pyrrole, 70 mL of anhydrous ferric chloride solution (4.2 g of anhydrous ferric chloride) and 0.03 g of a surfactant, sodium dodecylbenzene sulfonate, were added and stirring was continued. Then, the original sponge, which had been cleaned with deionized water and anhydrous ethanol, was placed in the above solution and in situ polymerized at 20°C for 5 h to obtain a polypyrrole sponge.

[0077] (2) 5 g of vinyltrimethoxysilane was first dissolved in 30 mL of tetrahydrofuran solution, and 0.04 g of diacyl peroxide as an initiator was added. The mixture was subjected to atomic free radical polymerization at 75 °C for 11 h under a nitrogen atmosphere. Then, 11 g of diethylaminoethyl methacrylate and 30 mL of tetrahydrofuran were added, and the polymerization was continued under a nitrogen atmosphere for 17 h to obtain a pH-responsive polymer solution (reaction flow diagram shown in FIG. 1 ). Figure 1 shown).

[0078] (3) The polypyrrole sponge obtained in (1) is immersed in the pH-responsive polymer solution obtained in (2), left to stand for 5 minutes, and after complete absorption, placed in an oven at 60°C and dried for 30 minutes, thereby finally obtaining a controllable oil-water separation material with pH responsiveness.

[0079] Comparative Example 1:

[0080] (1) The polyurethane sponge was cleaned with deionized water and anhydrous ethanol, and dried in a 50°C oven for 30 min to obtain the original sponge.

[0081] The scanning electron microscopy images of the prepared original sponge are shown in Figure 2. Figure 4 (aa”);

[0082] The water contact angles of the prepared original sponge in air with different pH values ​​are as follows: Figure 6 As shown;

[0083] The crude oil absorption of the prepared original sponge under (a) no light source and (b) with light source is shown in the figure. Figure 13 shown.

[0084] Comparative Example 2:

[0085] (1) The polyurethane sponge was cleaned with deionized water and anhydrous ethanol, and dried in a 50°C oven for 30 min to obtain the original sponge.

[0086] (2) The binder polyvinyl alcohol was stirred in deionized water to fully dissolve it. After it was fully dissolved, 0.3 g of pyrrole, 30 mL of anhydrous ferric chloride solution and 0.02 g of a surfactant sodium dodecylbenzene sulfonate were added and the stirring was continued. Then, the original sponge was placed in the above solution and in situ polymerized at 0°C for 4 h to obtain a polypyrrole sponge.

[0087] The scanning electron microscopy images of the prepared polypyrrole sponge are shown in Figure 2. Figure 4 (bb”) shown.

[0088] The above embodiments are not limitations of the present invention, and the present invention is not limited to the above embodiments. As long as the requirements of the present invention are met, they belong to the protection scope of the present invention.

[0089] The present invention grafts a pH-responsive polymer onto the surface of a polyurethane sponge to obtain a controllable oil-water separation material with switchable surface wettability for efficient separation of oil-water mixtures and adsorption and desorption of different oil products. At the same time, it also has excellent photothermal conversion capabilities, can effectively reduce crude oil viscosity and increase its absorption rate. The preparation method of the present invention is simple and feasible, with a wide source of raw materials and a high separation flux. The controllable oil-water separation material obtained can exhibit different surface wettabilities by adjusting the pH value, can achieve separation of different types of oil-water mixtures and adsorption and desorption of different oil products, and can also reduce crude oil viscosity and increase its absorption rate.

Claims

1. A method for preparing a pH-responsive controllable oil-water separation material, characterized in that: The steps include: (1) The original sponge cleaned with deionized water and anhydrous ethanol is placed in a mixed solution containing pyrrole, anhydrous ferric chloride as an oxidant, sodium dodecylbenzenesulfonate as a surfactant, and polyvinyl alcohol as a binder, and in situ polymerization is performed to obtain a polypyrrole sponge; (2) adding monomer A, diethylaminoethyl methacrylate, and initiator B into solvent C and stirring thoroughly, and then performing atomic free radical polymerization under a nitrogen or argon atmosphere to obtain a pH-responsive polymer solution; (3) Immerse the polypyrrole sponge obtained in (1) into the pH-responsive polymer solution obtained in (2), let it stand for 2-20 minutes, and after complete absorption, place it in an oven for drying to finally obtain a pH-responsive controllable oil-water separation material.

2. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (1), the mass ratio of the pyrrole, the oxidant anhydrous ferric chloride, the surfactant sodium dodecylbenzenesulfonate and the binder polyvinyl alcohol is 10-20:120-160:1:30-60.

3. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (2), the mass ratio of the monomer A, diethylaminoethyl methacrylate, initiator B and solvent C is 40-130:140-300:1:700-1500.

4. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (2), the monomer A is one or more of vinyltriethoxysilane and vinyltrimethoxysilane; The initiator B is one or more of azobisisobutyronitrile, diacyl peroxide, and potassium persulfate; The solvent C is one or more of tetrahydrofuran, N,N-dimethylformamide, and N-methylpyrrolidone.

5. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (1), the time of in-situ polymerization is 1-6 hours, and the temperature of in-situ polymerization is 0-30°C.

6. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (2), the time of atomic radical polymerization is 10-24 hours, and the temperature of atomic radical polymerization is 45-75°C.

7. The method for preparing the pH-responsive controllable oil-water separation material according to claim 1, wherein: In step (3), the drying temperature is 20-80°C; The drying time is 10-60 minutes.

8. Use of the pH-responsive controllable oil-water separation material prepared by the preparation method according to any one of claims 1 to 7 in oil-water separation.

9. Use of the pH-responsive controllable oil-water separation material prepared by the preparation method according to any one of claims 1 to 7 in the adsorption and desorption of oil products.

10. Use of the pH-responsive controllable oil-water separation material prepared by the preparation method according to any one of claims 1 to 7 in reducing crude oil viscosity.

Images