A porous super-hydrophobic material with photothermal and electrothermal functions, its preparation method, and oil-water separation application

Abstract

The present invention belongs to the field of oil-water separation technology, relates to the preparation of hydrophobic materials, and specifically to a porous super-hydrophobic material with photothermal and electrothermal functions, a preparation method thereof, and an oil-water separation application, for solving the technical problem that the poor fluidity of high-viscosity crude oil causes general super-hydrophobic materials to be difficult to effectively adsorb and treat by capillary force. A polyvinyl alcohol aqueous solution is mixed with a formaldehyde solution and a triton solution to prepare a foamed polyvinyl formal prepolymer; a carbon black / polyvinyl formal sponge is obtained after stirring evenly with a carbon black sulfuric acid dispersion and a closed reaction; the sponge is hydrophobically modified to obtain a photothermal and electrothermal super-hydrophobic modified polyvinyl formal sponge. The sponge has a hydrophobic angle of up to 154°, a photothermal test temperature of up to 76°C, and an electrothermal test temperature of up to 154°C. It has good hydrophobicity, photothermal properties, and electrothermal properties, and can utilize the temperature sensitivity of crude oil to adsorb high-viscosity oil spills.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil-water separation, relates to the preparation of hydrophobic materials, and specifically relates to a porous super-hydrophobic material with photothermal and electrothermal functions, a preparation method thereof, and oil-water separation applications. Background Art

[0002] Crude oil is a vital energy resource, and growing demand worldwide is driving offshore oil extraction and transportation. However, oil spills during this process not only cause economic losses but also cause significant damage to the marine ecosystem. Previous oil spill treatment methods, such as in-situ combustion, chemical emulsification and dispersants, and bioremediation, have limitations in both economic and environmental terms. Superhydrophobic and superoleophilic adsorbents effectively collect and treat oil spills, offering a promising approach to oil spill management.

[0003] Nowadays, the use of super-hydrophobic materials to process oil spills has received increasing attention and research, but current super-hydrophobic materials are mainly targeted at the leakage of low-viscosity crude oil. Due to the poor fluidity of high-viscosity crude oil, general super-hydrophobic materials are difficult to be effectively adsorbed and processed by capillary force. Temperature sensitivity is an important feature of crude oil, that is, the viscosity of crude oil will rapidly decrease with the increase of temperature. For now, the temperature sensitivity of crude oil can be used as an entry point to improve the adsorption of super-hydrophobic materials to high-viscosity crude oil, and super-hydrophobic adsorbent materials that generate heat can be developed. For example, Chinese patent CN115491020A discloses a Janus type composite foam photothermal functional material and its preparation method and application, i.e., one side super-hydrophilic / underwater super-oleophobic, the other side hydrophobic / super-oleophilic. The main preparation steps are as follows: (1) Preparation of photothermal functional layer: MXene nanosheets are first impregnated on one side of the porous foam by coating, and then a hydrophobic composite shielding layer is impregnated to give the MXene modified side excellent hydrophobic properties and antioxidant shielding effect; (2) Janus wettability construction: hydrophilic functional components are loaded on the opposite side of the MXene modified porous foam by impregnation to prepare a Janus-type MXene-based composite foam photothermal functional material with asymmetric wettability. The material has a high wettability at 1 kW / m 2 Under illumination, the temperature takes 360 seconds to rise to 50-70°C, reducing crude oil viscosity to below 500 mPa·s. However, this material requires dip-coating with MXene nanosheets and the "additional" use of polyurethane sponge to provide a porous material, making the method relatively complex. Furthermore, the adsorption performance for high-viscosity crude oil needs to be further improved. Summary of the Invention

[0004] To address the technical problem of high-viscosity crude oil's poor fluidity, which makes it difficult for typical superhydrophobic materials to effectively adsorb and treat it via capillary forces, this invention leverages crude oil's temperature sensitivity to improve superhydrophobic materials' adsorption of high-viscosity crude oil. This invention has developed a porous superhydrophobic material with photothermal and electrothermal functions, as well as its preparation method and application in oil-water separation. The sponge exhibits a hydrophobic angle of up to 152° (average) and a maximum of 154°. Photothermal testing temperatures can reach up to 76°C, and electrothermal testing temperatures can reach up to 154°C. This demonstrates excellent hydrophobicity, photothermal properties, and electrothermal properties, and can be used to adsorb and treat high-viscosity oil spills by leveraging crude oil's temperature sensitivity.

[0005] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A method for preparing a porous super-hydrophobic material with photothermal and electrothermal functions, comprising the following steps:

[0007] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution; prepare a sulfuric acid dispersion of carbon material;

[0008] (2) adding the Triton solution and the formaldehyde solution to the 20 wt % polyvinyl alcohol aqueous solution obtained in step (1), stirring and foaming, to obtain a foamed polyvinyl formal prepolymer;

[0009] (3) adding the sulfuric acid dispersion of the carbon material obtained in step (1) to the foamed polyvinyl formal prepolymer obtained in step (2), stirring evenly and then sealing to react, thereby obtaining a carbon material / polyvinyl formal sponge;

[0010] (4) The carbon material / polyvinyl formal sponge obtained in step (3) is cleaned and dried, and then hydrophobically modified to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0011] Furthermore, the carbon material in step (1) includes any one of carbon black nanoparticles, graphene, carbon nanotubes or graphyne; the preparation method of the carbon material sulfuric acid dispersion is: dispersing the carbon material in a sulfuric acid solution; the concentration of the carbon material sulfuric acid dispersion is 0.1-2 g / mL, the dispersion time is 60-180 min, and the mass fraction of the sulfuric acid solution is 25 wt%.

[0012] Furthermore, in step (2), the mass ratio of the 20 wt % polyvinyl alcohol aqueous solution to the Triton solution and the formaldehyde solution is 120:3:(20-24); and the stirring and foaming speed is 1000 rpm / min.

[0013] Furthermore, based on the 20 wt% polyvinyl alcohol aqueous solution in step (2), the mass ratio of the carbon material sulfuric acid dispersion to the 20 wt% polyvinyl alcohol aqueous solution in step (3) is (1-4):20; the temperature of the closed reaction is 60-70°C, and the closed reaction time is 2-3 hours.

[0014] Furthermore, the cleaning method in step (4) is: ultrasonic cleaning with water until the pH value of the aqueous solution is neutral; the drying temperature is 50-70°C, and the drying time is 24 hours.

[0015] Furthermore, the hydrophobic modification reagent in step (4) is a 1 wt% to 5 wt% n-hexane solution of silane or fluorinated silane.

[0016] Furthermore, the hydrophobic modification reagent in step (4) is a 1 wt% to 5 wt% n-hexane solution of alkylsilane or fluorine-containing silane.

[0017] Furthermore, in step (4), the hydrophobic modification temperature is room temperature, and the hydrophobic modification time is 12 to 24 hours.

[0018] Furthermore, the porous super-hydrophobic material with photothermal and electrothermal functions prepared by the above preparation method.

[0019] Furthermore, the porous super-hydrophobic material with photothermal and electrothermal functions is heated to 1 kW / m 2 After being irradiated under a xenon lamp for 200s, the surface temperature of the 3cm×2.5cm×1.5cm porous superhydrophobic material can reach up to 76°C; after being charged at a 3V-12V DC voltage for 240s, the surface temperature of the 3cm×2.5cm×1.5cm porous superhydrophobic material can reach up to 154°C.

[0020] Furthermore, the porous super-hydrophobic material with photothermal and electrothermal functions is used in oil-water separation.

[0021] Preferably, the porous super-hydrophobic material prepared by the present invention can realize adsorption treatment of high-viscosity crude oil, wherein the viscosity of the high-viscosity crude oil is greater than 10 3 mPa·s.

[0022] The present invention has the following beneficial effects:

[0023] 1. The present invention uses polyvinyl alcohol solution and formaldehyde solution to generate polyvinyl formal under acidic conditions as the main principle, prepares polyvinyl formal sponge prepolymer by adding a foaming agent Triton solution (TX-100), and uses carbon material as a photothermal and electric heating material. By doping with the polyvinyl formal sponge prepolymer, a porous superhydrophobic material with photothermal and electric heating functions is prepared. Photothermal and electric heating are conducive to the porous superhydrophobic material through a pump-assisted method to effectively adsorb high-viscosity crude oil on the sea surface.

[0024] 2. The hydrophobic angle of the porous super-hydrophobic material with photothermal and electrothermal functions can reach 152° (average) and a maximum of 154°. The surface temperature of the material can reach up to 76°C after 200s of photothermal testing, while the surface temperature of the material can reach up to 154°C after 240s of electrothermal testing. The good hydrophobicity, photothermal and electrothermal properties are conducive to the adsorption of high-viscosity oil spills. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is the hydrophobic angle of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention.

[0027] Figure 2 Photothermal testing of the porous superhydrophobic materials with photothermal and electrothermal functions prepared in Examples 1, 2, 3, and 4 of the present invention.

[0028] Figure 3 This is an electrothermal test of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 1 of the present invention.

[0029] Figure 4 This is an electrothermal test of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 2 of the present invention.

[0030] Figure 5 This is an electrothermal test of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 3 of the present invention.

[0031] Figure 6 This is an electrothermal test of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention.

[0032] Figure 7 These are infrared images of the 12V electric heating test of the porous superhydrophobic materials with photothermal and electric heating functions prepared in Examples 1, 2, 3, and 4 of the present invention.

[0033] Figure 8 This is a scanning electron microscope image of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention.

[0034] Figure 9This is a graph showing the change in crude oil viscosity with temperature in an application example of the present invention.

[0035] Figure 10 A crude oil adsorption experiment under light and electricity was conducted for the porous superhydrophobic material with photothermal and electrothermal functions in the application example of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0039] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0040] (2) Take 1 g of carbon black nanoparticles and disperse them in 25 wt% sulfuric acid solution for 1 h to prepare a 1 g / mL carbon black dispersion.

[0041] (3) Add 0.5 g of Triton solution (TX-100) and 4 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0042] (4) The carbon black dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the carbon black-doped polyvinyl formal prepolymer was sealed and reacted at 70°C for 2 hours to obtain a carbon black / polyvinyl formal sponge.

[0043] (5) The carbon black / polyvinyl alcohol formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 70°C for 24 hours. The carbon black / polyvinyl alcohol formal sponge was immersed in a 1wt% octadecyltrichlorosilane n-hexane solution for hydrophobic modification at room temperature for 24 hours. After the hydrophobic modification, the sponge was dried at 80°C for 24 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0044] Figure 3The photothermal and electrothermal superhydrophobic-modified polyvinyl formal sponge prepared in this example was subjected to electrothermal testing. When powered for 240 seconds at 3V, 6V, 9V, and 12V DC voltages, the surface temperatures of the 3cm×2.5cm×1.5cm superhydrophobic-modified polyvinyl formal sponge reached 20°C, 23°C, 28°C, and 41.9°C, respectively.

[0045] Example 2

[0046] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0047] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0048] (2) Take 2 g of carbon black nanoparticles and disperse them in 25 wt% sulfuric acid solution for 1 h to prepare a 1 g / mL carbon black dispersion.

[0049] (3) Add 0.5 g of Triton solution (TX-100) and 4 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0050] (4) The carbon black dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the carbon black-doped polyvinyl formal prepolymer was sealed and reacted at 70°C for 2 hours to obtain a carbon black / polyvinyl formal sponge.

[0051] (5) The carbon black / polyvinyl alcohol formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 70°C for 24 hours. The carbon black / polyvinyl alcohol formal sponge was immersed in a 1wt% octadecyltrichlorosilane n-hexane solution for hydrophobic modification at room temperature for 24 hours. After the hydrophobic modification, the sponge was dried at 80°C for 24 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0052] Figure 4 The photothermal and electrothermal superhydrophobic-modified polyvinyl formal sponge prepared in this example was subjected to electrothermal testing. When powered for 240 seconds at 3V, 6V, 9V, and 12V DC voltages, the surface temperatures of the 3cm×2.5cm×1.5cm superhydrophobic-modified polyvinyl formal sponge were 22°C, 30°C, 46°C, and 66.0°C, respectively.

[0053] Example 3

[0054] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0055] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0056] (2) Take 3 g of carbon black nanoparticles and disperse them in 25 wt% sulfuric acid solution for 1 h to prepare a 1 g / mL carbon black dispersion.

[0057] (3) Add 0.5 g of Triton solution (TX-100) and 4 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0058] (4) The carbon black dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the carbon black-doped polyvinyl formal prepolymer was sealed and reacted at 70°C for 2 hours to obtain a carbon black / polyvinyl formal sponge.

[0059] (5) The carbon black / polyvinyl formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 70°C for 24 hours. The carbon black / polyvinyl formal sponge was immersed in a 1 wt% n-hexane solution of 1H,1H,2H,2H-perfluorodecyltrichlorosilane for hydrophobic modification at room temperature for 24 hours. After the hydrophobic modification, the sponge was dried at 80°C for 24 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0060] Figure 5 The photothermal and electrothermal superhydrophobic-modified polyvinyl formal sponge prepared in this example was subjected to electrothermal testing. When powered for 240 seconds at 3V, 6V, 9V, and 12V DC voltages, the surface temperatures of the 3cm×2.5cm×1.5cm superhydrophobic-modified polyvinyl formal sponge reached 25°C, 50°C, 85°C, and 121°C, respectively.

[0061] Example 4

[0062] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0063] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0064] (2) Take 4 g of carbon black nanoparticles and disperse them in 25 wt% sulfuric acid solution for 1 h to prepare a 1 g / mL carbon black dispersion.

[0065] (3) Add 0.5 g of Triton solution (TX-100) and 4 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0066] (4) The carbon black dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the carbon black-doped polyvinyl formal prepolymer was sealed and reacted at 70°C for 2 hours to obtain a carbon black / polyvinyl formal sponge.

[0067] (5) The carbon black / polyvinyl formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 70°C for 24 hours. The carbon black / polyvinyl formal sponge was immersed in a 1 wt% 1H,1H,2H,2H-perfluorodecyltrichlorosilane n-hexane solution for hydrophobic modification at room temperature for 24 hours, and dried at 80°C for 24 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0068] Figure 6 The photothermal and electrothermal superhydrophobic-modified polyvinyl formal sponge prepared in this example was subjected to electrothermal testing. When powered for 240 seconds at 3V, 6V, 9V, and 12V DC voltages, the surface temperatures of the 3cm×2.5cm×1.5cm superhydrophobic-modified polyvinyl formal sponge reached 30°C, 60°C, 100°C, and 154°C, respectively.

[0069] Example 5

[0070] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0071] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0072] (2) Take 1 g of graphene and disperse it in 25 wt% sulfuric acid solution for 180 min to prepare a 2 g / mL graphene dispersion.

[0073] (3) Add 0.5 g of Triton solution (TX-100) and 3.33 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0074] (4) The graphene dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the graphene-doped polyvinyl formal prepolymer was sealed and reacted at 60°C for 3 hours to obtain a graphene / polyvinyl formal sponge.

[0075] (5) The graphene / polyvinyl formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 50°C for 24 hours. The graphene / polyvinyl formal sponge was immersed in a 2 wt% octadecyltrichlorosilane n-hexane solution for hydrophobic modification at room temperature for 12 hours. After the hydrophobic modification, the sponge was dried at 70°C for 24 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0076] Example 6

[0077] The preparation method of porous super-hydrophobic material with photothermal and electrothermal functions comprises the following steps:

[0078] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0079] (2) Take 1 g of graphyne and disperse it in 25 wt% sulfuric acid solution for 150 min to prepare a 0.1 g / mL graphyne dispersion.

[0080] (3) Add 0.5 g of Triton solution (TX-100) and 3.7 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0081] (4) The graphyne dispersion in (2) was added to the foamed polyvinyl formal prepolymer in (3) and stirred for 3 minutes. After stirring, the graphene-doped polyvinyl formal prepolymer was sealed and reacted at 65°C for 2.5 hours to obtain a graphyne / polyvinyl formal sponge.

[0082] (5) The graphyne / polyvinyl formal sponge in (4) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 60°C for 24 hours. The graphyne / polyvinyl formal sponge was immersed in a 5wt% octadecyltrichlorosilane n-hexane solution for hydrophobic modification at room temperature for 18 hours. After the hydrophobic modification, the sponge was dried at 80°C for 12 hours to obtain a porous superhydrophobic material with photothermal and electrothermal functions.

[0083] Comparative Example

[0084] The preparation method of super hydrophobic material comprises the following steps:

[0085] (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution;

[0086] (2) Add 0.5 g of Triton solution (TX-100) and 4 g of formaldehyde solution to 20 g of the polyvinyl alcohol aqueous solution in (1), and stir and foam the mixture at 1000 rpm for 6 min under an electric stirrer to obtain a foamed polyvinyl alcohol formal prepolymer.

[0087] (3) The foamed polyvinyl formal prepolymer was sealed and reacted at 70°C for 2 hours to obtain a polyvinyl formal sponge.

[0088] (4) The polyvinyl alcohol formal sponge in (3) was alternately ultrasonically cleaned with water until the pH value of the aqueous solution was about 7; the drying step was specifically: drying at 70°C for 24 hours. The polyvinyl alcohol formal sponge was immersed in a 1wt% n-hexane solution of 1H,1H,2H,2H-perfluorodecyltrichlorosilane at room temperature for 24 hours to perform hydrophobic modification. After the hydrophobic modification, the sponge was dried at 80°C for 24 hours to obtain a superhydrophobic material.

[0089] The electrothermal and photothermal properties of the superhydrophobic material were studied, and the study found that the superhydrophobic material only has hydrophobicity, but does not have electrothermal and photothermal properties.

[0090] Application Examples

[0091] The porous super-hydrophobic material with photothermal and electrothermal functions prepared in Example 4 was subjected to hydrophobic angle test, photothermal test, and electrothermal test (sponge volume: 3 cm × 2.5 cm × 1.5 cm). The morphological structure characterization results are as follows:

[0092] 1. Contact angle and morphological structure characterization

[0093] Figure 8 This is a scanning electron microscope image of a porous super-hydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention. Figure 8 As shown in the figure, the porous super-hydrophobic material with photothermal and electrothermal functions formed by adding a foaming agent Triton solution (TX-100) and carbon black nanoparticles and stirring sufficiently is filled with a macroporous structure with a pore size of about 100-400 μm.

[0094] By using 1H,1H,2H,2H-perfluorodecyltrichlorosilane for hydrophobic modification, Figure 1 The hydrophobic angle of the porous super-hydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention. Figure 1 As shown in the figure, the sponge surface has an excellent hydrophobic angle of 152° (average), with a maximum of 154°. The excellent hydrophobicity and the macroporous structure inside the sponge are more conducive to the adsorption of crude oil.

[0095] 2. Photothermal test and electrothermal test

[0096] Figure 2 Photothermal test of porous super-hydrophobic materials with photothermal and electrothermal functions prepared in Examples 1, 2, 3 and 4 of the present invention. Figure 2 As shown in the figure, the porous super-hydrophobic material with photothermal and electrothermal functions in Example 4 is heated to 1 kW / m 2 The surface temperature under xenon lamp irradiation can reach up to 76℃.

[0097] Figure 6 This is an electrothermal test of the porous superhydrophobic material with photothermal and electrothermal functions prepared in Example 4 of the present invention. Figure 7 This is an infrared photograph of the 12V electric heating test of the porous super-hydrophobic material with photothermal and electric heating functions prepared in Example 1, Example 2, Example 3, and Example 4 of the present invention. Figure 6 and Figure 7 As shown in the figure, after 240 seconds and 12V DC power supply, the surface temperature of the porous superhydrophobic material with photothermal and electrothermal functions reached 154°C. The temperature continued to rise with continued power supply. These excellent photothermal and electrothermal properties are beneficial for adsorbing high-viscosity oil spills.

[0098] 3. Crude oil adsorption experiments under light and electricity

[0099] The viscosity of the high-viscosity crude oil used in the present invention is statistically analyzed using a viscometer to measure changes in viscosity with temperature. Figure 9 This is a graph showing the change in crude oil viscosity with temperature in an application example of the present invention. Figure 9 As shown, the viscosity of high viscosity crude oil at room temperature is greater than 10 3 mPa·s. As the temperature increases, the temperature of high-viscosity crude oil gradually decreases. When the temperature reaches about 80°C, the viscosity is about 10 mPa·s.

[0100] Figure 10 Crude oil adsorption experiments were conducted on the photothermal and electrothermal super-hydrophobic modified polyvinyl formal sponge in the application example of the present invention under light irradiation and electric current.

[0101] Photothermal crude oil adsorption: When the light intensity is 1kW / m 2 Under the irradiation of a xenon lamp, a 3cm×2.5cm×1.5cm material was placed in 20mL of high-viscosity crude oil. Through the self-adsorption of the material and the assisted adsorption of the peristaltic pump, 5.1g of high-viscosity crude oil could be separated and cleaned after 15 minutes.

[0102] Electric heating crude oil adsorption: Power is supplied at 12V DC voltage, and a 3cm×2.5cm×1.5cm material is placed in 20mL of high-viscosity crude oil. Through the self-adsorption of the material and the auxiliary adsorption of the peristaltic pump, 6g of high-viscosity crude oil can be separated and cleaned after 90s.

[0103] Since the carbon materials listed in the present invention, such as carbon black nanoparticles, graphene, graphyne, carbon nanotubes, etc., have the same photothermal principle, namely molecular thermal vibration, and are all conductive, they can all be used to prepare porous superhydrophobic materials with photothermal and electrothermal functions.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a porous super-hydrophobic material with photothermal and electrothermal functions, characterized in that: Here are the steps: (1) Prepare a 20 wt% polyvinyl alcohol aqueous solution; prepare a sulfuric acid dispersion of carbon material; (2) adding the Triton solution and the formaldehyde solution to the 20 wt % polyvinyl alcohol aqueous solution obtained in step (1), stirring and foaming, to obtain a foamed polyvinyl formal prepolymer; (3) adding the sulfuric acid dispersion of the carbon material obtained in step (1) to the foamed polyvinyl formal prepolymer obtained in step (2), stirring evenly and then sealing to react, thereby obtaining a carbon material / polyvinyl formal sponge; (4) washing and drying the carbon material / polyvinyl formal sponge obtained in step (3), and then hydrophobically modifying the carbon material / polyvinyl formal sponge to obtain a porous superhydrophobic material with photothermal and electrothermal functions; The carbon material in step (1) includes any one of carbon black nanoparticles, graphene, carbon nanotubes or graphyne; the preparation method of the carbon material sulfuric acid dispersion is: dispersing the carbon material in a sulfuric acid solution; the concentration of the carbon material sulfuric acid dispersion is 0.1-2g / mL, the dispersion time is 60~180min, and the mass fraction of the sulfuric acid solution is 25wt%; Based on the 20 wt% polyvinyl alcohol aqueous solution in step (1), the mass ratio of the carbon material sulfuric acid dispersion to the 20 wt% polyvinyl alcohol aqueous solution in step (3) is (1-4):20; the temperature of the closed reaction is 60-70°C, and the closed reaction time is 2-3 hours.

2. The method for preparing a porous super-hydrophobic material having photothermal and electrothermal functions according to claim 1, wherein: In step (2), the mass ratio of the 20 wt % polyvinyl alcohol solution, the Triton solution, and the formaldehyde solution is 120:3:(20-24); the stirring and foaming temperature is room temperature, and the rotation speed is 1000 rpm.

3. The method for preparing a porous super-hydrophobic material with photothermal and electrothermal functions according to claim 2, wherein: The cleaning method in step (4) is: ultrasonic cleaning with water until the pH value of the aqueous solution is neutral.

4. The method for preparing a porous super-hydrophobic material with photothermal and electrothermal functions according to claim 3, wherein: The hydrophobic modification reagent in step (4) is a 1 wt% to 5 wt% n-hexane solution of silane or fluorinated silane.

5. The method for preparing a porous super-hydrophobic material with photothermal and electrothermal functions according to claim 4, wherein: In the step (4), the hydrophobic modification temperature is room temperature, and the hydrophobic modification time is 12 to 24 hours.

6. A porous superhydrophobic material with photothermal and electrothermal functions prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the porous superhydrophobic material with photothermal and electrothermal functions according to claim 6 in oil-water separation.

Images