High-performance conductive hydrophobic composite nanofiber membrane as well as preparation method and application thereof

Abstract

The invention discloses a high-performance conductive hydrophobic composite nanofiber membrane and a preparation method and application thereof.The method comprises the steps that under the action of ammonia water, silicon dioxide nanoparticles are modified through a silane coupling agent containing vinyl, vinyl modified silicon dioxide nanoparticles are obtained, and then the vinyl modified silicon dioxide nanoparticles are subjected to electrostatic spinning to obtain the high-performance conductive hydrophobic composite nanofiber membrane. Then carrying out grafting reaction on the polystyrene, benzoyl peroxide and styrene in methylbenzene at the temperature of 60-100 DEG C to obtain polystyrene grafted and modified silicon dioxide nanoparticles; the polystyrene graft modified silicon dioxide nanoparticles and a polymer film-forming agent are mixed in an organic solvent, an electrostatic spinning stock solution is obtained, the mass of the polystyrene graft modified silicon dioxide nanoparticles accounts for 4%-12% of the mass of the electrostatic spinning stock solution, and then electrostatic spinning is conducted to obtain a hydrophobic nanofiber membrane; the preparation method comprises the following steps of: soaking the composite nanofiber membrane into a conductive polymer solution, a carbon nano tube or a graphene solution for 5-20 minutes, then taking out and drying to obtain the high-performance conductive hydrophobic composite nanofiber membrane which shows excellent mechanical property and oil-water separation property.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of nanofiber membranes, and particularly relates to a high-performance conductive hydrophobic composite nanofiber membrane, a preparation method thereof, and an application thereof. Background Art

[0002] Frequent oil spill accidents and a large amount of oily wastewater generated in daily production and life pose threats to the ecological system, water resources, and human health. To solve this problem, membrane separation technology has emerged. Compared with traditional oil-water separation technologies, membrane filtration technology has the advantages of energy conservation, high cost performance, low secondary pollution, and wide applicability. Electrospinning technology can prepare fiber membranes with nano-porous structures, and membranes with selective wettability can significantly improve the oil-water separation performance.

[0003] For complex systems such as high-viscosity oil-water emulsions and oily wastewater, in addition to relying on the physical sieving and wettability difference principles of the membrane itself, conductive oil-water separation membranes also utilize the electric field effect to achieve excellent oil-water separation effects. Compared with traditional oil-water separation membranes, conductive oil-water separation membranes can quickly and efficiently separate oil-water mixtures under the action of an electric field, greatly shortening the separation time and improving the treatment efficiency.

[0004] Hydrophobic oils are easily adhered to the membrane surface or within the membrane pores during the filtration process, resulting in serious membrane fouling. Conductive membranes combine the dual advantages of membrane modification and electrochemistry and have been widely recognized in controlling organic and biological fouling, but the application of conductive membranes in the field of oil-water separation is still very limited.

[0005] Zhao Xinglei et al. added lithium chloride to the polyvinylidene fluoride spinning solution, which improved the conductivity, strengthened the adhesion between fibers, and ultimately improved the connectivity and stability of the membrane pores, enabling the membrane to have oil-water separation performance. However, the oil flux of the oil-water separation was only 780 L / m 2 ·h, and the separation efficiency was only 97%. Therefore, the separation performance of this hydrophilic polyvinylidene fluoride-lithium chloride blend membrane still needs to be improved. Summary of the Invention

[0006] To solve the problems of the above-mentioned prior art, the present invention provides a high-performance conductive hydrophobic composite nanofiber membrane, a preparation method thereof, and an application thereof, so as to solve the problem of insufficient separation performance of the current hydrophilic polyvinylidene fluoride-lithium chloride blend membrane. The obtained conductive hydrophobic composite nanofiber membrane exhibits excellent mechanical properties and oil-water separation performance.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A preparation method of a high-performance conductive hydrophobic composite nanofiber membrane, comprising the following steps: S1. Under the action of ammonia water, use a vinyl-containing silane coupling agent to modify silicon dioxide nanoparticles to obtain vinyl-modified silicon dioxide nanoparticles. Then, carry out a grafting reaction of vinyl-modified silicon dioxide nanoparticles, benzoyl peroxide, and styrene in toluene at 60 - 100 °C to obtain polystyrene-grafted modified silicon dioxide nanoparticles; S2. Mix the polystyrene-grafted modified silicon dioxide nanoparticles and a polymer film-forming agent in an organic solvent to obtain an electrospinning stock solution, where the polystyrene-grafted modified silicon dioxide nanoparticles account for 4% - 12% of the mass of the electrospinning stock solution. Then, carry out electrospinning to obtain a hydrophobic nanofiber membrane; S3. Immerse the hydrophobic nanofiber membrane in a conductive polymer solution, a carbon nanotube solution, or a graphene solution for 5 - 20 min, then take it out and dry it to obtain a high-performance conductive hydrophobic composite nanofiber membrane.

[0008] A further improvement of the present invention lies in: S1 obtains the above-mentioned vinyl-modified silicon dioxide nanoparticles according to the following process: According to the ratio of (1 - 5) g : (5 - 10) mL : (50 - 100) mL, add silicon dioxide particles and a vinyl-containing silane coupling agent to ethanol, stir at room temperature for 10 - 60 minutes, then add an ammonia water solution with a mass percentage of 25%. The volume ratio of the ammonia water solution to the vinyl-containing silane coupling agent is (5 - 10) : (5 - 15). Stir at room temperature for 12 - 36 h, centrifuge, wash with ethanol, and finally dry in vacuum to obtain powdery vinyl-modified silicon dioxide nanoparticles; The vinyl-containing silane coupling agent is vinyltriethoxysilane, vinyltris(2 - methoxyethoxy)silane, vinyltrimethoxysilane, vinyltrimethoxyethoxysilane, vinyltributylperoxysilane, or vinylmethyldimethoxysilane.

[0009] S1 obtains the above-mentioned polystyrene-grafted modified silicon dioxide nanoparticles according to the following process: According to the ratio of (1 - 5) g : (0.1 - 1) g : (50 - 100) mL, disperse the vinyl-modified silicon dioxide nanoparticles and benzoyl peroxide in toluene. Then, under stirring conditions, add styrene. The volume ratio of styrene to toluene is (10 - 50) : (50 - 100). Stir continuously at 60 - 100 °C for 3 - 5 h. Ultrasonically disperse the product in toluene, and then centrifuge to obtain polystyrene-grafted modified silicon dioxide nanoparticles.

[0010] The polymer film-forming agents described in S2 are polyacrylonitrile, polyvinyl alcohol, polylactic acid, polypropylene, polyvinylidene fluoride, polyvinyl chloride, polycaprolactone, polyethylene oxide, polyacrylic acid, polyvinylpyrrolidone or polyethyleneimine, and the organic solvents are dichloromethane, acetone, acetonitrile, ethyl acetate, benzene, chloroform, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide.

[0011] The ratio of the polymer film-forming agent to the organic solvent in the electrospinning stock solution is (1 - 5) g : (0.1 - 10) mL.

[0012] Before electrospinning in S2, a siliconized paper is wrapped on the rotating receiver. The temperature during electrospinning is 20 - 30 °C, the humidity is 35% - 45%, and the feeding rate is 0.5 - 1.5 mL / h, to obtain a hydrophobic nanofiber membrane attached to the siliconized paper.

[0013] In S3, the hydrophobic nanofiber membrane attached to the siliconized paper is washed with ethanol and then immersed in a conductive polymer solution, a carbon nanotube solution or a graphene solution for 5 - 20 min. Then the fiber membrane is dried at 60 - 80 °C, and the siliconized paper is peeled off to obtain a high-performance conductive hydrophobic composite nanofiber membrane.

[0014] The conductive polymers described in S3 are respectively polyaniline, polypyrrole, polythiophene, polycyanoethylene, polyacetylene, and the solvents of the corresponding solutions are respectively N,N-dimethylformamide, N-methylpyrrolidone, chloroform, acetone and toluene. The solvents of the carbon nanotube solution and the graphene solution are respectively N,N-dimethylformamide and toluene.

[0015] A high-performance conductive hydrophobic composite nanofiber membrane obtained by the preparation method of the high-performance conductive hydrophobic composite nanofiber membrane described in any one of the above.

[0016] Application of the high-performance conductive hydrophobic composite nanofiber membrane in oil-water separation.

[0017] Compared with the prior art, the present invention has the following beneficial effects: Preparation method of a high-performance conductive hydrophobic composite nanofiber membrane. The low surface energy property of SiO2 restricts the uniform distribution of water droplets on its surface. Through vinyl-modified SiO2 groups, an ordered spherical arrangement of SiO2 will form regular micro-protrusions and gaps on the surface, enhancing the hydrophobic property of the membrane and effectively regulating the surface chemical properties of the fiber membrane, thereby significantly reducing the interaction between water droplets and the membrane surface layer. By controlling the content of PS-grafted modified SiO2 in the electrospinning stock solution and the immersion time of the fiber membrane in conductive polymer solutions, carbon nanotube solutions or graphene solutions, the fiber pore structure of the composite nanofiber membrane can be regulated and the fiber diameter size can be increased, improving the hydrophobic property, oil-water separation property and mechanical property. The composite nanofiber membrane of the present invention has extremely high pore controllability, good mechanical properties and oil-water separation properties, can be applied to the field of oil-water separation, and solves the problems of traditional poly nanofiber oil-water separation membranes being easily contaminated, having high costs, complex preparation processes, poor oil absorption rates and poor durability. During the preparation process, high-energy-consuming equipment such as supercritical drying and freeze-drying is not required, and drying can be carried out under conventional conditions, with simple operation, green and environmentally friendly. Due to the hydrophobic and conductive characteristics of the oil-water separation membrane, it can be used for the separation of oil-water emulsions; the reaction conditions of the present invention are mild, the synthesis process is simple, energy-consuming is small, and post-treatment is simple.

[0018] Furthermore, by selecting different conductive polymer solutions, optimizing the temperature, humidity and feeding rate of electrospinning, and cleaning the nanofiber membrane with ethanol, different pore structures from nanoscale to microscale can be precisely designed for different conductive polymers, obtaining different types of composite nanofiber membranes, which can meet the requirements of different application scenarios for permeability, selectivity and mechanical strength.

[0019] The high-performance conductive hydrophobic composite nanofiber membrane of the present invention has an adjustable fiber structure, the water contact angle of the fiber membrane can reach 142°, has the characteristic of high hydrophobicity, and at the same time has high-performance oil-water separation characteristics. Description of the Drawings

[0020] Figure 1a SEM image of PS-grafted modified SiO2 at 1 μm in Example 1.

[0021] Figure 1b SEM image of PS-grafted modified SiO2 at 500 nm in Example 1.

[0022] Figure 2 Process diagram of the oil-water separation of an organic solvent by the oil-water separation membrane in Example 1.

[0023] Figure 3a Separation efficiency diagram of the oil-water separation membrane in Example 1 for different organic solvents.

[0024] Figure 3bFlux diagram of the oil-water separation membrane of Example 1 for different organic solvents.

[0025] Figure 4a SEM image at 100 μm of the conductive hydrophobic composite nanofiber membrane deposited for 5 min in Example 3.

[0026] Figure 4b SEM image at 50 μm of the conductive hydrophobic composite nanofiber membrane deposited for 5 min in Example 3.

[0027] Figure 4c SEM image at 100 μm of the conductive hydrophobic composite nanofiber membrane deposited for 10 min in Example 3.

[0028] Figure 4d SEM image at 50 μm of the conductive hydrophobic composite nanofiber membrane deposited for 10 min in Example 3.

[0029] Figure 4e SEM image at 100 μm of the conductive hydrophobic composite nanofiber membrane deposited for 20 min in Example 3.

[0030] Figure 4f SEM image at 50 μm of the conductive hydrophobic composite nanofiber membrane deposited for 20 min in Example 3.

[0031] Figure 5 Stress-strain diagram of the conductive hydrophobic composite nanofiber membranes of Examples 3-5.

[0032] Figure 6 Tensile strength and elongation at break diagram of the conductive hydrophobic composite nanofiber membranes of Examples 3-5. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] A preparation method of a conductive hydrophobic composite nanofiber membrane includes the following steps: 1) Preparation of vinyl-modified silica; The specific process is as follows: Ethanol, deionized water, and 25 wt% ammonia water with a volume ratio of 30 - 50:1 - 5:5 - 10 were stirred evenly to form a homogeneous mixed solution. Tetraethoxysilane was slowly added, and the volume ratio of tetraethoxysilane to ethanol was (5 - 10):(30 - 50), generating silicon dioxide nanoparticles. Stir at room temperature for 12 - 36 h, centrifuge, wash with ethanol, and dry in vacuum to obtain purified silicon dioxide nanoparticles.

[0035] Under the condition of vigorous stirring at 1000 r / min, 1 - 5 g of silicon dioxide particles and 5 - 10 mL of vinyl - containing silane coupling agent were successively added to 50 - 100 mL of ethanol, and stirred at room temperature for 10 - 60 minutes. Then 5 - 15 mL of 25 wt% ammonia water was added, and stirred at room temperature for 12 - 36 h. Centrifuge and wash with ethanol. Dry in vacuum to obtain powdery vinyl - modified silicon dioxide nanoparticles.

[0036] Vinyl - containing silane coupling agents include: Vinyltriethoxysilane, vinyltris(2 - methoxyethoxy)silane, vinyltrimethoxysilane, vinyltrimethoxyethoxysilane, vinyltri - tert - butylperoxysilane, vinylmethyldimethoxysilane.

[0037] 2) Polystyrene (PS) graft - modified silicon dioxide; The specific process is as follows: 1 - 5 g of vinyl - modified silicon dioxide nanoparticles were dispersed in 50 - 100 mL of toluene, and 0.1 - 1 g of benzoyl peroxide was added. Under the condition of vigorous stirring at 1000 r / min, 10 - 50 mL of freshly distilled styrene was added. Stir continuously at 60 - 100 °C for 3 - 5 h. The product was ultrasonically dispersed in toluene to remove unreacted styrene and polymer impurities, and then centrifuged to obtain polystyrene - graft - modified silicon dioxide nanoparticles.

[0038] 3) Preparation of electrospinning stock solution; The specific process is as follows: PS - graft - modified SiO2 with different contents was used as the solute and added to 0.1 - 10 mL of organic solvent, and mixed at room temperature. Then 1 - 5 g of polymer film - forming agent was added, so that PS - graft - modified SiO2 accounted for 4%, 8%, and 12% of the total mass of the three components respectively. Stir at room temperature for 4 - 6 hours until the solution becomes uniformly viscous to obtain the electrospinning stock solution.

[0039] Organic solvents are: Dichloromethane, acetone, acetonitrile, ethyl acetate, benzene, chloroform, tetrahydrofuran, N,N - dimethylformamide, N,N - dimethylacetamide, dimethyl sulfoxide.

[0040] The polymer film-forming agents are as follows: Polyacrylonitrile (PAN), polyvinyl alcohol, polylactic acid, polypropylene, polyvinylidene fluoride, polyvinyl chloride, polycaprolactone, polyethylene oxide, polyacrylic acid, polyvinylpyrrolidone, and polyethyleneimine.

[0041] 4) Preparation of a hydrophobic nanofiber membrane; The specific process is as follows: Inject the prepared electrospinning stock solution into a syringe. A 20 G metal needle is connected to a high-voltage power supply of 15 ± 3 kV, and the feeding rate is 1 ± 0.5 mL / h. The metal needle is 20 ± 5 cm away from the rotating receiver, and the rotating receiver is wrapped with siliconized paper. Electrospinning is carried out in an environment with a temperature of 25 ± 5 °C and a humidity of 40 ± 5 %, to obtain a hydrophobic nanofiber membrane (i.e., an oil-water separation membrane) attached to the siliconized paper.

[0042] 5) Preparation of a conductive nanofiber membrane.

[0043] The specific process is as follows: First, wash the oil-water separation membrane with ethanol to remove surface contaminants. Then immerse it in a conductive solution with a mass percentage of 1 - 5% for 5 - 20 min. After that, dry the fiber membrane at 60 - 80 °C, and then remove the siliconized paper to obtain a conductive hydrophobic composite nanofiber membrane.

[0044] The conductive materials are as follows: Polyaniline (the solvent is N,N-dimethylformamide), polypyrrole (the solvent is N-methylpyrrolidone), polythiophene (the solvent is chloroform), polycyanoethylene (the solvent is acetone), polyacetylene (the solvent is toluene), carbon nanotubes (the solvent is N,N-dimethylformamide), graphene (the solvent is toluene).

[0045] The conductive hydrophobic composite nanofiber membrane of the present invention is a nanofiber oil-water separation membrane, which is used as a separation membrane for the treatment of oily wastewater during application.

[0046] Example 1 (1) Stir 50 mL of ethanol, 1 mL of deionized water, and 10 mL of a 25% ammonia aqueous solution by mass percentage evenly to form a uniform mixed solution. Slowly add 10 mL of tetraethoxysilane to generate silicon dioxide nanoparticles. Stir at room temperature for 24 h, centrifuge, wash with ethanol, and dry in vacuum to obtain purified silicon dioxide nanoparticles.

[0047] Under vigorous stirring conditions, 1 g of silica particles and 10 mL of vinyltriethoxysilane were successively added to 100 mL of ethanol, and stirred at room temperature for 20 minutes. Then 10 mL of 25% ammonia water by mass was added, and stirred at room temperature for 24 h. Centrifuged and washed with ethanol. Vacuum dried to obtain powdery vinyl-modified silica nanoparticles.

[0048] The reaction formula is as follows:

[0049] (2) 1 g of vinyl-modified silica nanoparticles was dispersed in 50 mL of toluene, and 0.1 g of benzoyl peroxide (BPO) was added. Under vigorous stirring conditions, 10 mL of distilled styrene (St) was added. Stirred continuously at 75 °C for 4 h. The product was ultrasonically dispersed and washed in toluene, and centrifuged to obtain polystyrene-grafted modified silica nanoparticles.

[0050] The reaction formula is as follows:

[0051] (3) The PS-grafted modified SiO2 was added to 5 mL of N,N-dimethylformamide and mixed at room temperature. Then 1 g of PAN was added, and the PS-grafted modified SiO2 accounted for 4% of the total mass of the three. Stirred continuously at room temperature for 5 hours until the solution became uniformly viscous to obtain electrospinning stock solution 1 (the mass percentage of PS-grafted modified SiO2 was 4%).

[0052] (4) The prepared electrospinning stock solution 1 was injected into a syringe, and a 20 G metal needle was connected to a 15 kV high-voltage power supply, with a feeding rate of 1 mL / h. The metal needle was 20 cm away from the rotating receiver, and the rotating receiver was wrapped with silicone oil paper. Electrospinning was carried out in an environment with a temperature of 25 °C and a humidity of 40% to obtain an oil-water separation membrane 1 attached to the silicone oil paper.

[0053] (5) First, the oil-water separation membrane was washed with ethanol to remove surface contaminants. Then it was immersed in a 5 wt% polyaniline solution and deposited for 0.5 min. Then the fiber membrane was dried at 60 °C, and the silicone oil paper was peeled off to obtain a conductive oil-water separation membrane 1.

[0054] See Figure 1a and Figure 1b, SEM image of PS-grafted modified SiO2 in Example 1. It can be seen from the figure that the SiO2 treated by PS grafting still shows a highly ordered and neatly arranged spherical arrangement. The ordered spherical arrangement will form regular microscopic protrusions and gaps on the surface, thus affecting the wetting behavior of droplets. Polystyrene is hydrophobic, and the contact angle can be increased through ordered arrangement. This phenomenon also verifies that materials with higher surface roughness usually exhibit hydrophobicity.

[0055] Figure 2 Shows the oil-water separation device and its corresponding separation effect. The oil-water separation device consists of a sample injection bottle, a sand core filter joint, a clip, and a receiving bottle. The fiber membrane is fixed between the sample injection bottle and the sand core filter joint. The aqueous phase is stained with methylene blue, and the oil phase is stained with Sudan red III; when the oil phase contacts the interface of the fiber membrane, it will coalesce into a liquid phase layer on the membrane surface. Since the fiber membrane has hydrophobic and oleophilic properties, the oil phase selectively passes through the porous membrane interface, thereby achieving effective oil-water separation. Figure 3a and Figure 3b Shows the separation efficiency and flux of the fiber membrane for different organic solvents (dichloromethane, chloroform, petroleum ether, toluene, n-hexane). Chloroform shows a relatively high separation efficiency, reaching 99.2%, proving that the prepared fiber membrane can effectively separate oil-water mixtures.

[0056] Example 2 The PS-grafted modified SiO2 obtained in Example 1 was thoroughly mixed with 5 mL of N,N-dimethylformamide. Then 0.8 g of PAN was added, and the mixture was continuously stirred at room temperature for 5 hours until the solution became uniformly viscous, obtaining electrospinning stock solution 2 with a mass percentage of PS-grafted modified SiO2 of 8%.

[0057] The prepared electrospinning stock solution 2 was injected into a syringe, and a 20 G metal needle was connected to a 15 kV high-voltage power supply with a feeding rate of 1 mL / h. The metal needle was 20 cm away from the rotating receiver, and electrospinning was carried out in an environment with a temperature of 23 °C and a humidity of 42% to obtain an oil-water separation membrane 2.

[0058] First, the oil-water separation membrane 2 was washed with ethanol to remove surface contaminants. Subsequently, it was immersed in a 5wt% polyaniline solution for 0.5 min. Then the fiber membrane was dried at 60 °C and the silicon oil paper was removed to obtain a conductive hydrophobic composite membrane 2.

[0059] Example 3 The PS-grafted modified SiO2 obtained in Example 1 was thoroughly mixed with 5 mL of N,N-dimethylformamide solution. Then 0.6 g of PAN was added, and the mixture was continuously stirred at room temperature for 5 hours until the solution became uniformly viscous, obtaining electrospinning stock solution 3 with a mass percentage of PS-grafted modified SiO2 of 12%.

[0060] Inject the prepared electrospinning stock solution 3 into a syringe, connect it to a high-voltage power supply of 15 kV using a 20 G metal needle, and the feeding rate is 1 mL / h. The metal needle is 20 cm away from the rotating receiver, and electrospinning is carried out at a temperature of 20 °C and a humidity of 45% to obtain the oil-water separation membrane 3.

[0061] First, wash the oil-water separation membrane 3 with ethanol to remove surface contaminants. Then immerse it in a 5wt% polyaniline solution and deposit for 5 min. Then dry the fiber membrane at 60 °C and remove the silicon oil paper to obtain the conductive hydrophobic composite membrane 3.

[0062] Example 4 Obtain the oil-water separation membrane 3 according to the steps of Example 3, then wash it with ethanol to remove surface contaminants. Then immerse it in a 5wt% polypyrrole solution and deposit for 10 min. Then dry the fiber membrane at 60 °C and remove the silicon oil paper to obtain the conductive hydrophobic composite membrane 4.

[0063] Example 5 Obtain the oil-water separation membrane 3 according to the steps of Example 3, then wash it with ethanol to remove surface contaminants. Then immerse it in a 5wt% polythiophene solution and deposit for 20 min. Then dry the fiber membrane at 60 °C and remove the silicon oil paper to obtain the conductive hydrophobic composite membrane 5.

[0064] See Figure 4a , Figure 4b , Figure 4c , Figure 4d , Figure 4e and Figure 4f , which are the SEM images of the conductive hydrophobic composite membranes of Examples 3-5 respectively. It can be seen from the analogy of the images that the deposition duration significantly affects the apparent structure of the membrane. Prolonging the deposition process helps to achieve a full coverage of the fiber membrane surface, construct a more compact conductive coating, and thus enhance the performance of the membrane.

[0065] See Figure 5 and Figure 6 , which are the mechanical property diagrams of the conductive hydrophobic membranes of Examples 3-5. It can be seen from Figure 5 that the stress-strain curves of the three membranes show a similar pattern. As the strain increases, the stress shows an increasing trend until the membrane material breaks. In contrast, Figure 6 the composite membrane with a longer deposition time in

[0066] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation method of a high-performance conductive hydrophobic composite nanofiber membrane, characterized in that, It includes the following steps: S1. Under the action of ammonia water, modify silica nanoparticles with a vinyl-containing silane coupling agent to obtain vinyl-modified silica nanoparticles. Then, carry out a grafting reaction of vinyl-modified silica nanoparticles, benzoyl peroxide, and styrene in toluene at 60 - 100 °C to obtain polystyrene-grafted modified silica nanoparticles; S2. Mix polystyrene-grafted modified silica nanoparticles and a polymer film-forming agent in an organic solvent to obtain an electrospinning stock solution, where the polystyrene-grafted modified silica nanoparticles account for 4% - 12% of the mass of the electrospinning stock solution. Then, carry out electrospinning to obtain a hydrophobic nanofiber membrane; S3. Immerse the hydrophobic nanofiber membrane in a conductive polymer solution, a carbon nanotube solution, or a graphene solution for 5 - 20 min, and then take it out and dry it to obtain a high-performance conductive hydrophobic composite nanofiber membrane.

2. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 1, characterized in that, S1 obtains the above-mentioned vinyl-modified silica nanoparticles according to the following process: Add silica particles and a vinyl-containing silane coupling agent to ethanol according to the ratio of (1 - 5) g : (5 - 10) mL : (50 - 100) mL, stir at room temperature for 10 - 60 minutes, add an ammonia water solution with a mass percentage of 25% therein, the volume ratio of the ammonia water solution to the vinyl-containing silane coupling agent is (5 - 10) : (5 - 15), stir at room temperature for 12 - 36 h, centrifuge and then wash with ethanol, and finally dry under vacuum to obtain powdery vinyl-modified silica nanoparticles; The vinyl-containing silane coupling agent is vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltrimethoxysilane, vinyltrimethoxyethoxysilane, vinyltri-tert-butylperoxysilane, or vinylmethyldimethoxysilane.

3. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 1, wherein, S1 obtains the above-mentioned polystyrene-grafted modified silica nanoparticles according to the following process: Disperse vinyl-modified silica nanoparticles and benzoyl peroxide in toluene according to the ratio of (1 - 5) g : (0.1 - 1) g : (50 - 100) mL. Then, under stirring conditions, add styrene, the volume ratio of styrene to toluene is (10 - 50) : (50 - 100), continuously stir at 60 - 100 °C for 3 - 5 h, ultrasonically disperse the product in toluene, and then centrifuge to obtain polystyrene-grafted modified silica nanoparticles.

4. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 1, characterized in that, The polymer film-forming agent in S2 is polyacrylonitrile, polyvinyl alcohol, polylactic acid, polypropylene, polyvinylidene fluoride, polyvinyl chloride, polycaprolactone, polyethylene oxide, polyacrylic acid, polyvinylpyrrolidone, or polyethyleneimine, and the organic solvent is dichloromethane, acetone, acetonitrile, ethyl acetate, benzene, chloroform, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide.

5. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 4, characterized in that, The ratio of the polymer film-forming agent to the organic solvent in the electrospinning stock solution is (1 - 5) g : (0.1 - 10) mL.

6. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 1, characterized in that, Before electrospinning in S2, a siliconized paper is wrapped around a rotating receiver. During electrospinning, the temperature is 20 - 30 °C, the humidity is 35% - 45%, and the feeding rate is 0.5 - 1.5 mL / h, to obtain a hydrophobic nanofiber membrane attached to the siliconized paper.

7. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 6, characterized in that In S3, the hydrophobic nanofiber membrane attached to the siliconized paper is washed with ethanol and then immersed in a conductive polymer solution, a carbon nanotube solution or a graphene solution for 5 - 20 min. Then, the fiber membrane is dried at 60 - 80 °C, and the siliconized paper is peeled off to obtain a high-performance conductive hydrophobic composite nanofiber membrane.

8. The preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 1, characterized in that, The conductive polymers in S3 are respectively polyaniline, polypyrrole, polythiophene, polycyanoethylene, and polyacetylene, and the solvents of the corresponding solutions are respectively N,N-dimethylformamide, N-methylpyrrolidone, chloroform, acetone, and toluene. The solvents of the carbon nanotube solution and the graphene solution are respectively N,N-dimethylformamide and toluene.

9. A high-performance conductive hydrophobic composite nanofiber membrane obtained by the preparation method of the high-performance conductive hydrophobic composite nanofiber membrane according to any one of claims 1 - 8.

10. Application of the high-performance conductive hydrophobic composite nanofiber membrane according to claim 9 in oil-water separation.

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