Super-hydrophobic foam copper sheet, preparation method and application thereof and foam copper box

Abstract

The invention relates to the technical field of oil-water separation, in particular to a super-hydrophobic foam copper sheet, a preparation method and application thereof and a foam copper box. The invention provides a super-hydrophobic foam copper sheet. The super-hydrophobic foam copper sheet comprises a foam copper sheet body and a hydrophobic coating located on the surface of the foam copper sheet body. The hydrophobic coating is obtained by calcining preparation raw materials including a fluorinated ethylene-propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silicon dioxide nanoparticles. The super-hydrophobic foam copper sheet can realize continuous and rapid oil absorption, and has excellent oil-water separation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of oil-water separation, and in particular to a super-hydrophobic foam copper sheet, a preparation method and application thereof, and a foam copper box. Background Art

[0002] Oil pollution is a significant source of water contamination, severely damaging marine and aquatic ecosystems. To address this issue, existing methods for treating oil-water mixtures (gravity separation, chemical precipitation, and controlled combustion) suffer from drawbacks such as time-consuming, inefficient, high energy consumption, and the potential for secondary pollution. Therefore, efficiently separating oil from water remains a challenge. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a super-hydrophobic copper foam sheet, a preparation method and application thereof, and a copper foam box. The super-hydrophobic copper foam sheet can achieve continuous and rapid oil absorption and has excellent oil-water separation efficiency.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The present invention provides a super-hydrophobic copper foam sheet, comprising a copper foam sheet and a hydrophobic coating located on the surface of the copper foam sheet; The hydrophobic coating is obtained by calcining raw materials including fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silicon dioxide nanoparticles.

[0005] Preferably, the raw materials for preparing the hydrophobic coating include, by weight, 2 to 3 parts of fluorinated ethylene propylene copolymer, 2 to 3 parts of polyvinylidene fluoride, 1 to 2 parts of polyurethane and 2 to 3 parts of hydrophobic silica nanoparticles.

[0006] Preferably, the fluorinated ethylene propylene copolymer, polyvinylidene fluoride and hydrophobic silica nanoparticles have the same mass; The mass of the polyurethane is 1 / 3 of the mass of the fluorinated ethylene propylene copolymer.

[0007] Preferably, the foam copper sheet has a thickness of 0.8-1.4 mm and an average pore size of 140-280 μm.

[0008] The present invention also provides a method for preparing the super-hydrophobic copper foam sheet described in the above technical solution, characterized in that it comprises the following steps: mixing hydrophobic silica nanoparticles, fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and an organic solvent to obtain a mixed solution; After the mixed solution is sprayed on the surface of the foam copper sheet, calcination is performed to obtain the super-hydrophobic foam copper sheet.

[0009] Preferably, the concentration of hydrophobic silica in the mixed solution is 2-6 g / L.

[0010] Preferably, the spraying pressure is 3.5-4.0 bar, the spraying distance is 10-20 cm, and the number of times each side of the foam copper sheet is sprayed is 20-50 times.

[0011] Preferably, the calcination is carried out in a protective atmosphere; The calcination temperature is 220-260° C., and the calcination time is 60-100 minutes.

[0012] The present invention also provides the use of the super-hydrophobic copper foam sheet described in the above technical solution or the super-hydrophobic copper foam sheet prepared by the preparation method described in the above technical solution in the field of oil absorption.

[0013] The present invention also provides a foam copper box, comprising a polytetrafluoroethylene frame and super-hydrophobic foam copper sheets adhered to six sides of the polytetrafluoroethylene frame; The super-hydrophobic copper foam sheet is the super-hydrophobic copper foam sheet described in the above technical solution or the super-hydrophobic copper foam sheet prepared by the preparation method described in the above technical solution.

[0014] The present invention provides a kind of super-hydrophobic copper foam sheet, including copper foam sheet and the hydrophobic coating positioned at the surface of the copper foam sheet;The hydrophobic coating is calcined by the preparation raw materials including fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silica nanoparticles.The surface covering fluorine is formed by the synergistic effect of fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silica nanoparticles in the preparation raw materials of hydrophobic coating of the present invention, and a firm connection structure can be formed, and both greatly enhance hydrophobic stability, and the copper foam sheet prepared has excellent super-hydrophobicity, efficient, rapid separation and corrosion-resistant performance.Calcined after the mixed solution described in the surface spraying of copper foam sheet, the super-hydrophobic copper foam sheet internal surface roughness can be greatly increased, and then its oil absorption efficiency is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a physical picture of the polytetrafluoroethylene frame of the present invention; Figure 2 This is a physical picture of the foam copper box of the present invention; Figure 3 The SEM and EDS images of the coating before calcination described in Example 10; Figure 4 The SEM and EDS images of the calcined coating described in Example 10; Figure 5 The calcined coating of Example 10 (with Figure 4Surface element spectrum (the SEM image and EDS image correspond to the same position); Figure 6 This is a particle size analysis diagram of the FPUH mixture of the coating material before calcination in Example 11; Figure 7 SEM images of the pretreated copper foam sheet ((a) and (b)) and the prepared superhydrophobic copper foam sheet ((c) and (d)) described in Example 11 at different magnifications (200 μm, 100 μm); Figure 8 The BET pore size distribution curves of the pretreated copper foam sheet described in Example 11 and the copper foam sheet before and after calcination described in Example 11; Figure 9 This is the XPS spectrum of the super-hydrophobic copper foam described in Example 10; Figure 10 The water contact angles at different positions of the super-hydrophobic copper foam sheet described in Example 10; Figure 11 This is a photo of the foam copper box used in Example 12 to separate a peanut oil-water mixture; Figure 12 This is a physical picture of the separation of silicone oil-water mixture by the foam copper box described in Example 12; Figure 13 This is a photo of the separation of the vacuum pump oil-water mixture using the foam copper box described in Example 12; Figure 14 This is a photo of the separation of crude oil and water mixture by the copper foam box described in Example 12; Figure 15 The separation efficiency of the copper foam box described in Example 12 for oil-water separation of four different oils; Figure 16 The continuous working time of the copper foam box described in Example 13 for four different oils; Figure 17 Detailed illustrations of the super-hydrophobic copper foam sheet of Example 10, the super-hydrophobic copper foam sheet of Example 10 after being horizontally rolled, and the super-hydrophobic copper foam sheet of Example 10 after being folded four times and then unfolded; Figure 18 The water contact angles of the super-hydrophobic copper foam sheet of Example 10, the super-hydrophobic copper foam sheet of Example 10 after horizontal rolling, and the super-hydrophobic copper foam sheet of Example 10 after being folded four times and then unfolded; Figure 19 This is a photo of the corrosion resistance test of the super-hydrophobic copper foam sheet described in Example 10 in 1 mol / L hydrochloric acid and 1 mol / L sodium hydroxide solutions; Figure 20The water contact angle of the super-hydrophobic copper foam sheet described in Example 10 before and after being immersed in 1 mol / L hydrochloric acid and 1 mol / L sodium hydroxide solution for 30 min; Figure 21 Schematic diagram of the preparation process of superhydrophobic foam copper sheet, schematic diagram of the preparation process of foam copper box and schematic diagram of the application of foam copper box. DETAILED DESCRIPTION

[0016] The present invention provides a super-hydrophobic copper foam sheet, comprising a copper foam sheet and a hydrophobic coating located on the surface of the copper foam sheet; The hydrophobic coating is obtained by calcining raw materials including fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silicon dioxide nanoparticles.

[0017] In the present invention, the thickness of the copper foam sheet is preferably 0.8-1.4 mm, more preferably 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm; the pore size is preferably 140-280 μm, more preferably 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, or 280 μm. In an embodiment of the present invention, the thickness of the copper foam sheet is specifically 1.0 mm, and the pore size is specifically 200 μm.

[0018] In the present invention, the percentage of the thickness of the hydrophobic coating to the thickness of the foam copper sheet is preferably ≤10%.

[0019] In the present invention, the average particle size of the polyurethane is preferably 160-280 mesh, more preferably 160 mesh, 180 mesh, 200 mesh, 220 mesh, 240 mesh or 280 mesh. In an embodiment of the present invention, the average particle size of the polyurethane is specifically 200 mesh.

[0020] In the present invention, the average particle size of the fluorinated ethylene propylene copolymer is preferably 8-18 μm, more preferably 8 μm, 10 μm, 12 μm, 14 μm, 16 μm or 18 μm. In an embodiment of the present invention, the average particle size of the fluorinated ethylene propylene copolymer is specifically 12 μm.

[0021] In the present invention, the average particle size of the polyvinylidene fluoride is preferably less than 15 μm.

[0022] In the present invention, the raw materials for preparing the hydrophobic coating of the present invention preferably include 2 to 3 parts of fluorinated ethylene propylene copolymer, 2 to 3 parts of polyvinylidene fluoride, 1 to 2 parts of polyurethane and 2 to 3 parts of hydrophobic silica nanoparticles, calculated by weight.

[0023] The raw materials used to prepare the hydrophobic coating of the present invention preferably include 2-3 parts by weight of a fluorinated ethylene-propylene copolymer, with the fluorinated ethylene-propylene copolymer more preferably comprising 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0 parts by weight. In the present invention, the fluorinated ethylene-propylene copolymer serves to introduce a fluorinated polymer (fluororesin) with low surface energy fluorine. It has excellent heat resistance, corrosion resistance, durability, and weather resistance, as well as low surface energy, and has therefore been frequently used in recent years as a raw material for oil-water separation materials.

[0024] Based on the mass fraction of the fluorinated ethylene propylene copolymer, the raw material for preparing the hydrophobic coating of the present invention preferably includes 2 to 3 parts of polyvinylidene fluoride, and the mass fraction of the polyvinylidene fluoride is more preferably 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts or 3.0 parts. In the present invention, the role of the polyvinylidene fluoride is to introduce a low surface energy substance fluorine element while increasing the compatibility of the fluorinated ethylene propylene copolymer with polyurethane by the introduction of the substance.

[0025] With the mass fraction of described fluorinated ethylene propylene copolymer as benchmark, the preparation raw material of hydrophobic coating of the present invention preferably comprises 1~2 parts of polyurethane, and the mass fraction of described polyurethane is more preferably 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts or 2.0 parts. In the present invention, the effect of described polyurethane is to have high selective adsorption performance, is a kind of porous material for rapid oil removal, becomes one of the most general base materials for preparing super hydrophobic super oleophilic material. one .

[0026] Based on the mass fraction of the fluorinated ethylene propylene copolymer, the raw materials for preparing the hydrophobic coating of the present invention preferably include 2 to 3 parts of hydrophobic silica nanoparticles, and the mass fraction of the hydrophobic silica nanoparticles is more preferably 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts or 3.0 parts. In the present invention, the role of the hydrophobic silica nanoparticles is that the hydrophobic silica nanoparticles are firmly attached to the polyurethane surface, so that the polyurethane surface produces nanoscale roughness, which is used to absorb grease floating on the water surface.

[0027] In the present invention, the masses of the fluorinated ethylene propylene copolymer, polyvinylidene fluoride and hydrophobic silica nanoparticles are preferably equal; and the mass of the polyurethane is preferably 1 / 3 of the mass of the fluorinated ethylene propylene copolymer.

[0028] The present invention also provides a method for preparing the super-hydrophobic copper foam sheet described in the above technical solution, characterized in that it comprises the following steps: mixing hydrophobic silica nanoparticles, fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and an organic solvent to obtain a mixed solution; After spraying the mixture on the surface of the copper foam sheet, calcining is performed to obtain the super hydrophobic copper foam sheet (such as Figure 21 shown).

[0029] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art.

[0030] The invention mixes hydrophobic silicon dioxide nanoparticles, fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and an organic solvent to obtain a mixed liquid.

[0031] In the present invention, the organic solvent is preferably one or more of ethanol, propanol, and acetone. When the organic solvent comprises two or more of the above-mentioned substances, the present invention does not impose any particular restrictions on the ratio of the above-mentioned substances; the above-mentioned substances may be mixed in any ratio. In an embodiment of the present invention, the organic solvent is specifically ethanol (anhydrous ethanol).

[0032] In the present invention, the mixing is preferably performed after the organic solvent and the hydrophobic silica nanoparticles are stirred and mixed, and then the fluorinated ethylene propylene copolymer, polyvinylidene fluoride and polyurethane are added. The present invention does not have any special restrictions on the stirring and mixing process, and the process well known to those skilled in the art can be used. After adding the fluorinated ethylene propylene copolymer, polyvinylidene fluoride and polyurethane, the present invention further preferably includes ultrasonic dispersion; the present invention does not have any special restrictions on the ultrasonic dispersion process, and the process well known to those skilled in the art can be used. In an embodiment of the present invention, the stirring and mixing process is specifically carried out under the condition of covering with plastic wrap, and the stirring and mixing time is specifically 30 minutes; the ultrasonic dispersion time is specifically 10 minutes.

[0033] In the present invention, the concentration of the hydrophobic silica in the mixed solution is preferably 2-6 g / L, more preferably 2.0 g / L, 3.0 g / L, 4.0 g / L, 5.0 g / L or 6.0 g / L. In an embodiment of the present invention, the concentration of the hydrophobic silica in the mixed solution is specifically 4 g / L.

[0034] After obtaining the mixed liquid, the present invention sprays the mixed liquid on the surface of the foam copper sheet and then calcines the mixed liquid to obtain the super-hydrophobic foam copper sheet.

[0035] Before spraying, the present invention also preferably includes pre-treating the copper foam sheet, wherein the pre-treatment includes sequentially cutting, pickling, cleaning, and drying. The present invention does not impose any particular restrictions on the cutting process, and a process familiar to those skilled in the art can be used. In the present invention, the acid solution used for pickling is preferably hydrochloric acid with a concentration of 1 mol / L; the pickling is preferably performed under ultrasonic conditions, and the ultrasonication time is preferably 5 minutes; the cleaning agent used for cleaning is preferably distilled water, and the number of cleanings is preferably 3 to 4. In the present invention, the cleaning is preferably completed within 0.5 minutes to minimize prolonged contact of the copper foam with air, otherwise the cleaned copper foam will react again with oxygen, water, and carbon dioxide in the air. In the present invention, the drying temperature is preferably 60°C, and the drying time is preferably 30 minutes. In an embodiment of the present invention, the size of the cut copper foam sheet is specifically 3×3 cm; the pickling process specifically involves immersing the sheet in a 1 mol / L hydrochloric acid solution using ultrasonic waves for 5 minutes; the cleaning process specifically involves rinsing the sheet with distilled water 3-4 times; and the drying temperature specifically is 60°C and the drying time specifically is 30 minutes. In the present invention, the pickling process is used to remove impurities such as copper oxide, basic copper carbonate, and other trace metals and their compounds from the surface of the copper foam sheet.

[0036] In the present invention, the spraying pressure is preferably 3.5-4.0 bar, more preferably 3.5 bar, 3.6 bar, 3.7 bar, 3.8 bar, 3.9 bar or 4.0 bar; the spraying distance is preferably 10-20 cm, more preferably 15 cm; the number of times each side of the foam copper sheet is sprayed is preferably 20-50 times, more preferably 30 times. In an embodiment of the present invention, the spraying pressure is specifically 4.0 bar, the spraying distance is specifically 15 cm, and the number of times each side of the foam copper sheet is sprayed is specifically 30 times.

[0037] After the spraying is completed, the present invention preferably further comprises placing the foam copper sheet obtained after the spraying in a fume hood to allow the ethanol to evaporate rapidly.

[0038] In the present invention, the calcination is preferably carried out in a protective atmosphere; the protective atmosphere is preferably a nitrogen atmosphere and / or helium, more preferably a nitrogen atmosphere. In the present invention, the calcination temperature is preferably 220-260°C, more preferably 220°C, 230°C, 240°C, 250°C or 260°C; the calcination time is preferably 60-100 minutes, more preferably 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes or 120 minutes. In an embodiment of the present invention, the calcination is specifically carried out in a nitrogen atmosphere, the calcination temperature is specifically 240°C, and the calcination time is specifically 90 minutes.

[0039] The present invention also provides the use of the super-hydrophobic copper foam sheet described in the above technical solution or the super-hydrophobic copper foam sheet prepared by the preparation method described in the above technical solution in the field of oil absorption.

[0040] The present invention also provides a foam copper box, comprising a polytetrafluoroethylene frame and super-hydrophobic foam copper sheets (such as Figure 2 structure shown); The super-hydrophobic copper foam sheet is the super-hydrophobic copper foam sheet described in the above technical solution or the super-hydrophobic copper foam sheet prepared by the preparation method described in the above technical solution.

[0041] In the present invention, the polytetrafluoroethylene frame (such as Figure 1 The preparation method of the structure shown in FIG2 is preferably 3D printing. The present invention does not have any special limitation on the 3D printing process, and the process well known to those skilled in the art can be used.

[0042] In the present invention, the method for preparing the foam copper box comprises the following steps: The super hydrophobic copper foam sheet was bonded to the six sides of the polytetrafluoroethylene frame using a glass adhesive to obtain the copper foam box (eg Figure 21 shown).

[0043] The present invention does not have any special limitation on the type of glass adhesive and the bonding process, and any type and bonding process well known to those skilled in the art can be used.

[0044] In the present invention, the foam copper box is a hollow box. A silicone tube is inserted into a hole on one side of the foam copper box, and the connection between the silicone tube and the hole is glued tightly with glass adhesive. When powered by a peristaltic pump, oil and water separation can be achieved, forming a combination of oil boom and oil skimmer functions. Therefore, in actual application, a number of foam copper boxes (such as Figure 21 As shown in the figure, the oil and water can be quickly separated and recovered after the oil leak. The oil-water separation system can then be applied to the actual treatment of crude oil leaks and has broad prospects.

[0045] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] Examples 1 to 14 Preparation method of super hydrophobic copper foam sheet: The copper foam sheets were cut into small pieces of 3 cm × 3 cm, immersed in a 1 mol / L hydrochloric acid solution for 5 min using ultrasonic waves, and quickly washed with distilled water 3 to 4 times. The small pieces of copper foam sheets were then dried in an oven at 60°C for 30 min to obtain pretreated copper foam sheets. Ethanol and hydrophobic silica nanoparticles were mixed in a beaker, stirred for 30 minutes, and covered with plastic wrap. Ultrafine polyurethane (UPU, average particle size of about 200 mesh), polyvinylidene fluoride (PVDF, average particle size <15 μm), and fluorinated ethylene propylene copolymer (FEP, average particle size of about 12 μm) were added, and ultrasonic dispersion was used for 10 minutes to obtain a mixed solution (denoted as FPUH mixed solution). Under the conditions of a spraying pressure of 4.0 bar and a spraying distance of 15 cm, the FPUH was sprayed 30 times on each side of the pretreated copper foam sheet, and then placed in a fume hood to allow the ethanol to evaporate rapidly. The sheet was then calcined in a tube furnace at 240° C. in a nitrogen atmosphere for 90 min to obtain a superhydrophobic copper foam sheet. Preparation of foam copper box: Prepare the polytetrafluoroethylene frame by 3D printing; A hole was drilled in a super-hydrophobic copper foam sheet, and an oil-absorbing silicone tube was inserted into the hole. Glass adhesive was then used to seal the connection between the rubber tube and the hole. Finally, the two were bonded to one side of a polytetrafluoroethylene frame. The super-hydrophobic copper foam sheet was bonded to the polytetrafluoroethylene frame on the other five sides using glass adhesive to form a cubic copper foam box.

[0047] The amounts of the raw materials used in Examples 1 to 9, the water contact angles of the prepared super-hydrophobic copper foam sheets, and the orthogonal test results are shown in Table 1: Table 1 The amount of raw materials used in the preparation of Examples 1 to 9, the water contact angle of the prepared super-hydrophobic copper foam sheets, and the orthogonal test results

[0048] As can be seen from Table 1, the contact angles of the superhydrophobic copper foam sheets prepared by changing the dosage ratio of the raw materials will vary greatly. According to the results of the water contact angle, the average contact angle indicators corresponding to the three levels of equal amounts of FEP and PVDF are 142.97°, 145.06°, and 145.03°, respectively. It can be seen that the second level, i.e. 0.050g, has the best effect on the experimental indicators; the average contact angles corresponding to the three levels of UPU are 144.82°, 144.82°, and 143.43°, respectively. It is not difficult to see that the second level, i.e. 0.035g, has the best effect on the experimental indicators; the average contact angles corresponding to the three levels of hydrophobic silica nanoparticles are 144.25°, 144.59°, and 144.22°, respectively. It can be seen that the second level, i.e. 0.10g, has the best effect on the experimental indicators; according to the results of the orthogonal experiment, the range R corresponding to the three factors of equal amounts of FEP and PVDF, the amount of UPU, and the amount of hydrophobic silica nanoparticles are 2.09, 1.39, and 0.37, respectively. It can be seen that of the three experimental factors, the amount of hydrophobic silica nanoparticles has the greatest impact on the experimental indicators. The order of influence of each factor on the experimental indicators is: equal amounts of FEP and PVDF > amount of UPU > amount of hydrophobic silica nanoparticles. Example 5 achieves the best results in terms of water contact angle, with an amount of 0.05g of equal amounts of FEP and PVDF, 0.035g of UPU, and 0.10g of hydrophobic silica nanoparticles. The amounts of the raw materials used in Examples 10 to 14 and the water contact angles of the super-hydrophobic copper foam sheets obtained are shown in Table 2: Table 2 Amounts of raw materials used in Examples 10 to 14 and water contact angles of the prepared super-hydrophobic copper foam sheets

[0049] Comparative Example 1 Refer to Example 14, except that the calcination temperature is 220° C. The water contact angle of the obtained hydrophobic foam copper sheet is 142.4°.

[0050] Comparative Example 2 Refer to Example 14, except that the calcination temperature is 260° C. The water contact angle of the obtained hydrophobic foam copper sheet is 140.3°.

[0051] Test Case Figure 3 The SEM and EDS images of the coating before calcination in Example 10, wherein (a) is the SEM and EDS image of the outer layer of the coating, and (b) is the SEM and EDS image of the inner layer of the coating. Figure 3It can be seen that the outer and inner sides of the coating before calcination contain C, O, F, Si, and N elements, but the content on the outer side of the coating is significantly higher than that on the inner side. In particular, the content of O, F, and Si elements on the inner side of the coating is very small, only 4.70%, 0.89%, and 1.24%, respectively. This indicates that after spraying, a large number of micro-nano particles are attached to the outer side of the foam copper sheet skeleton and are unevenly distributed. Figure 4 The SEM and EDS images of the calcined coating described in Example 10, wherein (a) is the SEM and EDS image of the outer layer of the coating, and (b) is the SEM and EDS image of the inner layer of the coating. Figure 4 It can be seen that the elements inside and outside the calcined copper foam coating are still the same, and the content of each element is relatively uniform. Although the content of F elements on the inside of the coating is still lower than that on the outside of the coating, the content of F elements on the inside is greatly increased. This may be because the heat treatment temperature is 240°C, the FEP resin has not melted, and the energy flows to a lower place. A small amount of F elements flows to the outside of the coating, forming a micro-convex structure, increasing the surface roughness; some F elements flow to the inside of the coating, that is, the area inside the pores of the copper foam that is less covered by the FPUH coating, resulting in a more uniform distribution of the coating on the surface of the three-dimensional pore network structure of the copper foam, and further verifies the conjecture of the reduction of F element content in the XPS analysis. Therefore, the FPUH coating on the surface of the copper foam after calcination is evenly distributed, which is not only beneficial to the hydrophobic performance, but also improves the durability of the material during the oil absorption process. Figure 5 The calcined coating of Example 10 (with Figure 4 The surface element spectrum of the SEM image and EDS image (corresponding to the same position) is obtained by Figure 5 It can be seen that its surface is evenly covered with C, N, O, F, and Si elements, indicating that the FPUH coating is evenly adhered to the surface of the foam copper sheet; Figure 6 The particle size analysis diagram of the FPUH mixture of the coating material before calcination in Example 11 is shown in FIG. Figure 6 It can be seen that the particle size of the coating mixture is between 1μm and 200μm, with the largest range being between 10μm and 100μm, which meets the conditions for preparing superhydrophobic materials, namely, superhydrophobic materials must have low surface energy, good surface roughness and surface micro / nanostructure. The spraying of the FPUH mixture with the above suitable particle size distribution range on the surface of the copper foam and subsequent calcination enables the surface of the foam copper sheet material to construct low surface energy and achieve nano- and micron-level roughness; Figure 7 The SEM images of the pretreated copper foam sheet ((a) and (b)) and the prepared super-hydrophobic copper foam sheet ((c) and (d)) described in Example 11 at different magnifications (200 μm, 100 μm) are shown. Figure 7It can be seen that the surface of the pre-treated copper foam is relatively smooth and flat, and does not have the surface roughness characteristics of super-hydrophobicity. The three-dimensional structure of the super-hydrophobic copper foam has a surface roughness of sodium and micron levels. In addition, FPUH also contains low surface energy fluoroethylene propylene (FEP) and polyvinylidene fluoride (PVDF). This simultaneously meets the requirements of constructing sodium and micron-level roughness on the surface of the copper foam and giving it low surface energy. Figure 8 The BET pore size distribution curves of the pretreated copper foam sheet described in Example 11 and the copper foam sheet before and after calcination described in Example 11 are shown in FIG. Figure 8 It can be seen that there is no significant difference in the pore size range of the above three, except that the pore size range of the FPUH coated copper foam sheet before calcination is larger, 120-400μm. The pore size range of the copper foam sheet and the calcined FPUH coated copper foam sheet is relatively consistent, both in the pore size range of 120-340nm. In general, the order of pore size is: copper foam sheet before calcination > The calcined copper foam sheet is larger than the pre-treated copper foam sheet. In addition, compared with the copper foam sheet, the pore size ratio of the calcined FPUH-coated copper foam sheet in the range of 120-340μm has slightly decreased, but it can still maintain 93.3% of the volume content of the same pore size range of the original copper foam sheet. This shows that the calcined FPUH-coated copper foam sheet does not significantly affect the inner diameter of the copper foam sheet. Instead, it effectively increases the roughness of the internal surface of the copper foam sheet, and also introduces elements such as F and Si that reduce the surface energy of the material. Figure 9 The XPS spectrum of the super-hydrophobic copper foam sheet described in Example 10 is Figure 9It can be seen that elements such as O, C, F, and Si are present on the surface of the copper foam. O primarily originates from polyurethane and hydrophobic silica, both of which are present in a significant proportion in FPUH coatings. Therefore, O has the highest content, with its characteristic peak at 532.51 eV. C is present in FEP, PVDF resin, and polyurethane, while F originates from FEP and PVDF resins, and Si clearly originates from hydrophobic silica. Calculating the elemental ratios based on the FPUH powder (unsintered copper foam) yields 30.34%, 28.89%, 16.14%, 16.72%, 4.39%, and 3.52% of O, F, C, Si, N, and H, respectively. Instrumental measurements of the sintered copper foam material reveal that the proportions of O, F, C, Si, and N in the measured elements are 43.99%, 9.87%, 22.17%, 21.85%, and 2.11%, respectively. Comparing the two, we found that O still had the highest content, while C and Si showed similar percentages with little change. However, the F content decreased. This is likely due to the FEP resin not melting at 240°C, allowing a small amount of F to escape to the surface and some to the inside of the pores of the copper foam, resulting in a decrease in the F surface content. However, this also demonstrates that the FPUH coating adheres to the three-dimensional skeleton of the copper foam, indicating a low-energy surface material. Figure 10 is the water contact angle at different positions of the super-hydrophobic copper foam sheet described in Example 10, Figure 10 As can be seen from a in the figure, when a needle with a diameter of about 0.6 mm is used to drop about 10 μL of distilled water on the surface of the FPUH-coated copper foam sheet, the contact angle is 150.79°, which shows that the modified copper foam sheet has good hydrophobicity. The contact angles of different positions of the same copper foam sheet are measured. Figure 10 As can be seen from Figures b-d, the contact angles are 150.32°, 150.03°, and 149.32°, respectively, demonstrating excellent hydrophobicity. This demonstrates that FPUH can be used to modify copper foam sheets with good results. Measurements at various locations on multiple samples revealed a contact angle range of 148±2° for the FPUH-coated copper foam sheet. This indicates that the sprayed FPUH powder is evenly distributed on the copper foam sheet, resulting in excellent surface hydrophobicity. The foam copper box described in Example 12 was subjected to an oil-water separation test: The method of the oil-water separation experiment is as follows: take a 250mL beaker filled with tap water, weigh it and record its weight as M1, then add the oil phase to form an oil-water mixture and record it as M2. After the peristaltic pump is connected to the foam copper box for separation, the remaining oil-water mixture is recorded as M3. At the same time, the separation working time is recorded. The oil absorption separation efficiency is used to measure the oil-water separation performance of the foam copper box. The calculation formula of the oil-water separation efficiency is shown in Formula 1: R = ( M 2-M 3) / ( M 2- M 1) × 100% Formula 1; The foam copper box described in Example 12 was used to separate the peanut oil-water mixture (150 mL of tap water and 20 mL of peanut oil). The actual picture during the experiment is as follows: Figure 11 The sequential process from (a) to (d) is carried out as follows: the copper foam box is connected to one end of the silicone tube, and a peristaltic pump (power set to 25W, the same power is used for all subsequent oil absorption experiments) provides power to achieve in-situ oil-water separation; the other end of the silicone tube is connected to a beaker to collect the separated peanut oil; during the oil-water separation process, it can be clearly seen that the copper foam box absorbs oil and repels water at the boundary of the oil-water mixture, with good hydrophobic and lipophilic effects. After 2.5 minutes, almost 20mL of peanut oil has been separated; the water surface is clean and there is no water in the beaker where the components are collected. The separation efficiency of peanut oil and peanut oil reaches 97.22%. This shows that the copper foam box is effective in oil-water separation. The foam copper box described in Example 12 was used to separate the silicone oil-water mixture (150 mL of tap water and 20 mL of silicone oil (the silicone oil was dyed red)). The actual picture during the experiment is as follows Figure 12 The process of (a) to (d) is carried out in sequence: the foam copper box described in Example 12 is placed in the silicone oil-water mixture, the peristaltic pump is turned on to start oil-water separation, and after 3 minutes, the mixture is as follows Figure 12 As shown in (c) and (d), only a small amount of silicone oil remains in the beaker containing the oil-water mixture, adhering to the wall of the beaker. The silicone oil in the oil collector is clean and free of impurities (water). The separation efficiency of silicone oil and water reaches 97.90%. The foam copper box described in Example 12 was used to separate the vacuum pump oil-water mixture (150 mL of tap water (dyed blue) and 20 mL of vacuum pump oil). The actual picture during the experiment is as follows Figure 13 The sequential process from (a) to (d) is as follows: Due to the high viscosity of vacuum pump oil, adsorption is slow, and oil-water separation is completed after 4.5 minutes. The collected oil component (vacuum pump oil) is of very high purity, and the separation effect is very obvious. The separation efficiency of vacuum pump oil and water is as high as 98.20%; The foam copper box described in Example 12 was used to separate the crude oil-water mixture (150 mL of tap water and 20 mL of crude oil). The actual picture of the experimental process is shown in the figure below. Figure 14(a) shows the crude oil-water separation process. As the peristaltic pump is turned on, crude oil immediately flows through the foam copper box and silicone tubing into the beaker. After 30 seconds, the crude oil is almost completely separated. (b) and (c) are comparison images before and after 2 minutes of oil-water separation, respectively. As shown in (b) and (c), a small amount of crude oil remains in the beaker containing the oil-water mixture, as well as a small amount adhering to the walls. The cup containing the crude oil is completely free of water. The crude oil-water separation efficiency reaches 91.57%, demonstrating excellent separation results. In summary, the foam copper box described in Example 12 was used to conduct oil-water separation tests on four different oils, and the separation effects were as follows: Figure 15 As shown, the separation efficiency of the foam copper box described in Example 12 for peanut oil, silicone oil, vacuum pump oil, and crude oil are 97.22%, 97.90%, 98.20%, and 91.57%, respectively, all of which are above 90%, proving that the foam copper box can achieve in-situ oil-water separation. Among them, the separation effect on the vacuum pump oil-water mixture is the best, up to 98.20%, and the separation effect on crude oil-water is the worst, but still reaches 91.57%, still with good separation ability. At the same time, the foam copper box has the fastest separation rate for crude oil, and can separate more oil in the same time. The results of the oil-water separation experiment show that the foam copper box has the ability to continuously, efficiently, and in-situ separate oil-water mixtures; Considering the continuous working separation effect of the foam copper box, the continuous working time of the box was tested: four oil-water mixtures were continuously separated by the foam copper box until water droplets appeared in the beaker collecting the oil component, which was recorded as the continuous working time of the oil phase: 150mL of tap water and 20mL of the oil-water mixture were initially separated until no obvious oil layer appeared in the oil-water mixture. Then 40mL of oil was added. After no oil layer appeared on the surface of the oil-water mixture, the collected oil was poured into the oil-water mixture until water droplets appeared in the collector. The working time t was recorded; The foam copper box described in Example 13 was subjected to a hydrophobic stability test. Figure 16 The continuous working time of the foam copper box described in Example 13 for four different oils is as follows: Figure 16It can be seen that the continuous working time of the foam copper box described in Example 13 for peanut oil, silicone oil, vacuum pump oil and crude oil are 23 minutes, 30 minutes, 80 minutes and 9 minutes respectively. Among them, the vacuum pump oil has a continuous working time of up to 80 minutes and still does not absorb water. At the same time, we can find that the viscosity of the four oils, crude oil, peanut oil, silicone oil and vacuum pump oil, is getting higher and higher, so its fluidity is getting lower and lower; the lower the viscosity, the greater the fluidity and the shorter the working time. Crude oil has the highest fluidity. Under the external power of the peristaltic pump, it passes through the foam copper box quickly and may take away a small amount of FPUH coating. At the same time, the crude oil covers the FPUH coating, and the holes of the foam copper sheet are not blocked by the crude oil, and it begins to absorb water under the external power. Vacuum pump oil has the highest viscosity and has good hydrophobicity. After the pump oil covers the foam copper box, it may block the holes of the foam copper sheet due to its high viscosity. In addition, the pump oil itself has strong hydrophobicity, so after working for a long time, it can still isolate water outside the foam copper box under external power. Folding wear test: The super-hydrophobic copper foam sheet of Example 10, the super-hydrophobic copper foam sheet of Example 10 after being horizontally rolled, and the super-hydrophobic copper foam sheet of Example 10 after being folded four times and unfolded (the actual picture is as shown in the following order) are placed in the container. Figure 17 The water contact angle test was performed as shown in (a), (b) and (c) in the figure; the test results are shown in Figure 18 As shown by Figure 18 It can be seen that the water contact angle of the super-hydrophobic copper foam sheet described in Example 10 is 149.11°, and the water contact angles of the super-hydrophobic copper foam sheet after the first three foldings are 143.26°, 141.05° and 143.00°, respectively. The contact angles are all above 140°, and still have good hydrophobic properties, indicating that the super-hydrophobic copper foam sheet has good anti-folding collision ability, but after four foldings, the contact angle drops to 138.21°, and the hydrophobic property decreases to a certain extent. Corrosion resistance test: Figure 19 (a) is a physical picture of the super-hydrophobic copper foam sheet of Example 10 immersed in 1mol / L hydrochloric acid, (b) is a process of removing the super-hydrophobic copper foam sheet of Example 10 after being immersed in 1mol / L hydrochloric acid for 30min, (c) is a physical picture of the super-hydrophobic copper foam sheet after being removed, (d) is a physical picture of the super-hydrophobic copper foam sheet of Example 10 immersed in 1mol / L sodium hydroxide solution, (e) is a process of removing the super-hydrophobic copper foam sheet of Example 10 after being immersed in 1mol / L sodium hydroxide solution for 30min, and (f) is a physical picture of the super-hydrophobic copper foam sheet after being removed; Figure 19 It can be seen that the surface of the super-hydrophobic copper foam sheet is still very dry after being taken out of the hydrochloric acid and sodium hydroxide solutions, and has a certain acid and alkali resistance. Figure 20 The water contact angle of the super-hydrophobic copper foam sheet described in Example 10 after being immersed in 1 mol / L hydrochloric acid and 1 mol / L sodium hydroxide solution for 30 min is given by Figure 20 It can be seen that the contact angles of the super-hydrophobic copper foam described in Example 10 before immersion in acid and alkali solutions are 149.92° and 148.55° respectively; the water contact angle after soaking in hydrochloric acid for 30min is 144.95°, and the water contact angle after soaking in sodium hydroxide aqueous solution for 30min is 142.58°. The hydrophobicity of the copper foam is good, indicating that the copper foam prepared has certain acid and alkali resistance. At the same time, the contact angles before and after acid and alkali immersion are compared. It can be seen that the contact angle decreases by 4.9° after acid immersion and decreases by 5.9° after alkali immersion, so the influence of 1mol / L sodium hydroxide solution on the copper foam is greater than that of 1mol / L hydrochloric acid solution. The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A super hydrophobic copper foam sheet, characterized in that: It comprises a foam copper sheet and a hydrophobic coating located on the surface of the foam copper sheet; The hydrophobic coating is obtained by calcining raw materials including fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and hydrophobic silicon dioxide nanoparticles.

2. The super-hydrophobic copper foam sheet according to claim 1, wherein The raw materials for preparing the hydrophobic coating include, by weight, 2 to 3 parts of fluorinated ethylene propylene copolymer, 2 to 3 parts of polyvinylidene fluoride, 1 to 2 parts of polyurethane and 2 to 3 parts of hydrophobic silica nanoparticles.

3. The super-hydrophobic copper foam sheet according to claim 1 or 2, wherein The masses of the fluorinated ethylene propylene copolymer, polyvinylidene fluoride and hydrophobic silica nanoparticles are equal; The mass of the polyurethane is 1 / 3 of the mass of the fluorinated ethylene propylene copolymer.

4. The super-hydrophobic copper foam sheet according to claim 1 or 2, wherein The thickness of the foam copper sheet is 0.8-1.4 mm, and the average pore diameter is 140-280 μm.

5. the preparation method of the described super hydrophobic copper foam sheet of any one of claim 1~4, is characterized in that, The following steps are involved: mixing hydrophobic silica nanoparticles, fluorinated ethylene propylene copolymer, polyvinylidene fluoride, polyurethane and an organic solvent to obtain a mixed solution; After the mixed solution is sprayed on the surface of the foam copper sheet, calcination is performed to obtain the super-hydrophobic foam copper sheet.

6. The preparation method according to claim 5, wherein The concentration of hydrophobic silica in the mixed solution is 2-6 g / L.

7. The preparation method according to claim 5, wherein The spraying pressure is 3.5-4.0 bar, the spraying distance is 10-20 cm, and the number of times each side of the foam copper sheet is sprayed is 20-50 times.

8. The preparation method according to claim 5, wherein The calcination is carried out in a protective atmosphere; The calcination temperature is 220-260° C., and the calcination time is 60-100 minutes.

9. Application of the super-hydrophobic copper foam sheet according to any one of claims 1 to 4 or the super-hydrophobic copper foam sheet prepared by the preparation method according to any one of claims 5 to 8 in the field of oil absorption.

10. A foam copper box, characterized in that: The invention comprises a polytetrafluoroethylene frame and super-hydrophobic copper foam sheets adhered to six sides of the polytetrafluoroethylene frame; The super-hydrophobic copper foam sheet is the super-hydrophobic copper foam sheet according to any one of claims 1 to 4 or the super-hydrophobic copper foam sheet prepared by the preparation method according to any one of claims 5 to 8.

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