Preparation method and application of double-sided dual-property foam metal-based three-dimensional coupling water collection material

Abstract

The invention discloses a preparation method and application of a double-sided double-property foam metal-based three-dimensional coupling water collection material, and particularly relates to the technical field of air water collection, and the preparation method comprises the following specific steps: step 1, immersing foamy copper into an ethanol solution for ultrasonic pretreatment; step 2, immersing the pretreated foamy copper into a mixed solution of NaOH and K2S2O8, then taking out the foamy copper, continuously replacing the foamy copper with deionized water, soaking the foamy copper until the solution is clear, and then drying the foamy copper to obtain hydrophilic foamy copper; 3, polystyrene, a dichloromethane solution, a Dow Corning DC184 solution, a curing agent of the Dow Corning DC184 solution and titanium dioxide powder are mixed and then evenly coated on a glass slide, and a hydrophobic coating is obtained; and 4, completely covering the hydrophobic coating with hydrophilic foamy copper, and putting the hydrophobic coating into a drying oven for vapor deposition. The water collecting material prepared by the method is of a three-dimensional network structure, has the characteristics of double surfaces and double properties, is good in air permeability, and can improve the water collecting efficiency when being applied to an air water collecting device.

Description

Technical Field

[0001] The present invention relates to the technical field of air water collection, and in particular to a preparation method and application of a double-sided bisexual foam metal-based three-dimensional coupled water collection material. Background Art

[0002] In the atmosphere, water exists primarily in the form of clouds, fog, and water vapor, providing a plentiful alternative water resource. However, its utilization is often overlooked by most people. Therefore, atmospheric water harvesting is considered one of the key technologies currently used to overcome global water scarcity.

[0003] Currently, air-water collection materials are expensive, difficult to desorb, and have low water collection rates, making them unsuitable for mass production. Therefore, the present invention provides a method for preparing and applying a double-sided, bi-functional, metal-foam-based three-dimensional coupled water-collecting material with good air permeability, high water collection efficiency, and environmental friendliness. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a double-sided and bisexual foam metal-based three-dimensional coupled water-collecting material. The prepared water-collecting material presents a three-dimensional network structure and has the characteristics of double-sided and bisexuality, good air permeability, and can be used in air water collection devices to improve water collection efficiency.

[0005] In order to achieve the above-mentioned object, the present invention provides the following technical solution: a method for preparing a double-sided bisexual metal foam-based three-dimensional coupled water-collecting material, the specific steps of which are as follows:

[0006] Step 1: immerse the copper foam (CF) in ethanol solution for ultrasonic pretreatment;

[0007] Step 2: Immerse the pretreated copper foam in a mixed solution of NaOH and K2S2O8, then take it out and soak it in deionized water continuously until the solution is clear, and then dry it to obtain hydrophilic copper foam [Cu(OH)2@CF];

[0008] Step 3: After the polystyrene and dichloromethane solution are stirred and mixed, Dow Corning DC184 solution and its curing agent, and titanium dioxide powder are added in sequence, and after stirring to form a mixture, the mixture is evenly coated on a glass slide. After the surface is completely solidified, a hydrophobic coating is prepared;

[0009] Step 4: Completely cover the hydrophilic copper foam [Cu(OH)2@CF] on the hydrophobic coating, place it in an oven for vapor deposition, and then take it out to obtain a double-sided biphilic foam metal-based three-dimensional coupled water-collecting material [BC@Cu(OH)2@CF].

[0010] Vapor deposition technologies primarily fall into two categories: chemical vapor deposition (CVD) and physical vapor deposition (PVD). Specifically, CVD involves introducing two or more gaseous or liquid reactants into a reaction chamber under vacuum and high temperature conditions, where a chemical reaction occurs on the wafer surface, forming a new material that is then deposited. PVD involves physically converting a material into a gaseous state and depositing the desired thin film on the substrate. PVD is further categorized into vacuum evaporation, sputtering, and ion plating.

[0011] The present invention adopts physical vapor deposition (PVD) technology, that is, in a high temperature environment, the film material is liquefied and then gasified by an external heat source, and then deposited on a substrate.

[0012] Compared with the existing double-sided and bisexual water-collecting materials that are prepared by spraying to attach hydrophilic / hydrophobic substances to the material surface, which are prone to problems such as easy shedding of surface microstructures, poor air permeability, and being unfavorable for long-term adsorption of water vapor in the air, the present invention uses vapor deposition technology to attach polymer hydrophobic component particles to the material surface, providing a micro-nano rough structure, thereby effectively constructing a super-hydrophobic surface and making the material performance more stable.

[0013] Preferably, the copper foam in step one and the glass slide in step three are of the same size.

[0014] Preferably, the mass ratio of NaOH to K2S2O8 in step 2 is 3:2.

[0015] Preferably, in step 3, the amount of polystyrene added is 1-3 g, the amount of dichloromethane solution added is 10-20 mL, and the amount of titanium dioxide powder added is 3-4 g.

[0016] Preferably, in step 3, the Dow Corning DC184 solution and its curing agent are vinyl-terminated polydimethylsiloxane and a platinum catalyst, respectively, and the mass ratio of vinyl-terminated polydimethylsiloxane to the platinum catalyst is 10:1.

[0017] Preferably, in step 4, the oven temperature is 120° C. and the vapor deposition time is 3-4 minutes.

[0018] The double-sided and biphilic foam metal-based three-dimensional coupled water-collecting material prepared by the preparation method of the present invention is used in an air water collection device. The hydrophilic surface of the material captures water vapor contained in the air, and the collected water vapor is transported to the hydrophobic surface through the three-dimensional porous structure of the material, gradually grows and gathers into large droplets on the hydrophobic surface, and then slides along the hydrophobic surface to be collected. It has a strong capture-transport capability and can improve the water collection efficiency.

[0019] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0020] 1. The double-sided and bi-sexual foam metal-based three-dimensional coupled water-collecting material prepared by the present invention has the characteristics of double-sided and bi-sexual. The hydrophilic layer quickly captures water vapor, and the hydrophobic layer causes water vapor to condense and transport quickly, shortening the time it takes for the material to reach saturation, thereby improving water collection efficiency;

[0021] 2. The double-sided bisexual metal foam-based three-dimensional coupled water-collecting material prepared by the present invention presents a three-dimensional network structure, which allows fluid to flow freely inside it, allowing air to contact the material over a larger area, thereby improving the material's air permeability and capture capacity;

[0022] 3. The raw material cost of the present invention is low and easy to obtain. Compared with the existing double-sided and bisexual water-collecting materials, which are prepared by spraying to attach hydrophilic / hydrophobic substances to the surface of the material, which are prone to problems such as easy shedding of surface microstructures, poor air permeability, and being unfavorable for long-term adsorption of water vapor in the air, the preparation method of the present invention adopts vapor deposition technology to attach polymer hydrophobic component particles to the surface of the material, providing a micro-nano rough structure, thereby effectively constructing a super-hydrophobic surface, making the material performance more stable, and the preparation process simple and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The preparation flow chart of double-sided biphilic metal foam-based three-dimensional coupled water-collecting materials;

[0024] Figure 2 (ac), (df) and (gi) are SEM analysis images of the hydrophobic surfaces of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF, respectively;

[0025] Figure 3 (a), (b) and (c) are EDS analysis images of the hydrophobic surfaces of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF, respectively;

[0026] Figure 4 TEM analysis of Cu(OH)2@CF;

[0027] Figure 5 (a-b) are the XRD and XPS analysis diagrams of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF, respectively; (c) is the Cu 2p peak fitting diagram of Cu(OH)2@CF; (d) is the Si 2p peak fitting diagram of the hydrophobic surface of Cu(OH)2@CF;

[0028] Figure 6 Take photos of samples and test contact angles;

[0029] Figure 7 This is the mirror phenomenon diagram of BC@Cu(OH)2@CF;

[0030] Figure 8 This is the experimental diagram of the unidirectional water conduction performance test of BC@Cu(OH)2@CF;

[0031] Figure 9 This is the test diagram of the hydrophobic surface of BC@Cu(OH)2@CF using the tilted plate method;

[0032] Figure 10 (a) is the air permeability test diagram when water vapor is introduced, and (b) is the air permeability test diagram when air is introduced;

[0033] Figure 11 Diagram of the experimental setup for testing the water collection performance of CF, Cu(OH)2@CF, and BC@Cu(OH)2@CF;

[0034] Figure 12 The water collection capacity-time relationship diagram of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF (the material size is 3×3cm 2 );

[0035] Figure 13 The water collection capacity and water collection efficiency of BC@Cu(OH)2@CF after 10 cycles (material size is 3×3cm) 2 );

[0036] Figure 14 A new air water collection device (left) and an enlarged image of the water collection chamber (right) equipped with a double-sided and bi-philic foam metal-based three-dimensional coupled water collection material. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] 1. The present invention provides Figure 1 The preparation method of the double-sided biphilic metal foam-based three-dimensional coupled water-collecting material shown in the figure comprises the following specific steps:

[0039] First, 3×3cm 2 Copper foam (CF) was immersed in ethanol solution for ultrasonic pretreatment for 1 h and then taken out for use;

[0040] The pretreated CF was then immersed in a solution of NaOH and K2S2O8 with a mass ratio of 3:2. After 1 hour, it was taken out and immersed in deionized water continuously until the solution was clear. After that, it was taken out and dried to obtain hydrophilic copper foam [Cu(OH)2@CF].

[0041] Then, after 2 g of polystyrene and 15 mL of dichloromethane solution were fully stirred, Dow Corning DC184 solution and its curing agent (vinyl-terminated polydimethylsiloxane and platinum catalyst) with a mass ratio of 10:1 and 3-4 g of titanium dioxide powder were added in sequence. The mixture was stirred until uniformly mixed to obtain a mixture, and then the mixture was evenly coated on a 3×3 cm 2 On a glass slide, after the surface is completely solidified, a hydrophobic coating is prepared;

[0042] Finally, the hydrophilic copper foam [Cu(OH)2@CF] was completely covered on the hydrophobic coating, placed in a 120°C oven for 3.5 minutes, and taken out after vapor deposition. The high molecular weight hydrophobic components on the coating were converted into vapor under the two conditions of high temperature and specific time and adhered to the contact surface between the material and the coating, thus obtaining a double-sided and biphilic foam metal-based three-dimensional coupled water-collecting material [BC@Cu(OH)2@CF].

[0043] The bifacial, double-sided, metal-based foam-based three-dimensional coupled water-collecting material, fabricated by this invention, features one super-hydrophilic surface and one super-hydrophobic surface. This material is inspired by the natural phenomenon of organisms utilizing their hydrophilic / hydrophobic micro-nanostructures to absorb water. The material exhibits excellent air permeability, with the hydrophilic surface capturing airborne water vapor. This captured water vapor is transported through the material's three-dimensional porous structure to the hydrophobic surface, where it gradually grows and coalesces into large droplets. These droplets then slide down the hydrophobic surface and are collected. This strong capture and transport capability improves water collection efficiency.

[0044] 2. Characterization and analysis test:

[0045] 1. Scanning electron microscopy (SEM): SEM analysis of the hydrophobic surfaces of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF Figure 2 As shown. Figure 2 From (ac), we can see that the surface of CF is relatively smooth. Figure 2 From the (df), it can be seen that the roughness and specific surface area of Cu(OH)2@CF are increased, indicating that the hydrophilic component is successfully loaded on its surface; compared with Figure 2 (ac), Figure 2 The roughness of the hydrophobic surface of BC@Cu(OH)2@CF in (gi) is also significantly increased, but the microstructure is not changed because the hydrophobic components on its surface are loaded uniformly and densely. Figure 2 There is no significant difference in (df).

[0046] 2. Elemental analysis (EDS): EDS analysis of the hydrophobic surfaces of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF Figure 3 As shown. Figure 3It can be seen that compared with CF, the O element content on the surface of the prepared Cu(OH)2@CF is significantly increased, and the Cu element content is reduced, indicating that the surface is loaded with hydrophilic components; the Si element content on the hydrophobic surface of BC@Cu(OH)2@CF is increased, and the Si element comes from the hydrophobic component, which shows that the high molecular weight hydrophobic substance is successfully loaded on the Cu(OH)2@CF surface.

[0047] 3. Transmission electron microscopy analysis (TEM): TEM analysis of Cu(OH)2@CF is as follows Figure 4 As shown. Figure 4 It can be seen that a complex is formed on the CF surface after solution immersion, which provides a substrate with a large specific surface area for the loading of hydrophobic components.

[0048] 4. X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS): Figure 5 From (a), we can see that the XRD spectrum of CF has typical diffraction peaks at 2θ=44.50°, 51.84°, and 76.37°, which are distributed on the (111), (200), and (220) lattice planes of CF, respectively. Cu(OH)2@CF has typical diffraction peaks at 2θ=38.00°, 39.80°, 44.50°, 51.84°, and 76.37°, which are distributed on the (041), (130), (111), (200), and (220) lattice planes of Cu(OH)2@CF, respectively. The vapor deposition method causes the high molecular weight hydrophobic components to attach to the surface of the material. Such substances cannot show characteristic diffraction peaks. Therefore, the diffraction peak positions and numbers of Cu(OH)2@CF and BC@Cu(OH)2@CF in the XRD analysis are basically the same. Figure 5 (b) shows that in CF, the binding energies near 298 and 545 eV correspond to the absorption peaks of two elements, C and O. The binding energies near 299, 546 and 952 eV in Cu(OH)2@CF correspond to the absorption peaks of three elements, C, O and Cu, which shows that Cu(OH)2 is successfully loaded on the CF surface. The binding energies near 100.2, 150.5, 299, 546 and 952 eV in BC@Cu(OH)2@CF correspond to the absorption peaks of five elements, Si2p, Si 2s, C, O and Cu. Figure 5 From (c), we can see that the Cu 2p spectrum in Cu(OH)2@CF can be divided into three peaks at 932.4, 933.01 and 952.16 eV, which further demonstrates that Cu(OH)2 is successfully loaded on the CF surface. Figure 5 As shown in (d), the Si 2p spectrum in BC@Cu(OH)2@CF has three separate component peaks at 100.89, 102.2 and 103.02 eV, which belong to Si 2p 3 / 2Electronic state. Comparison shows that the BC@Cu(OH)2@CF surface is successfully loaded with high molecular weight hydrophobic components.

[0049] 3. Performance test:

[0050] 1. Contact angle test: The contact angle of the hydrophilic surface of BC@Cu(OH)2@CF prepared by solution immersion and vapor deposition is 0°, showing superhydrophilicity; the contact angle of the hydrophobic surface of the material is 156.8°, showing superhydrophobicity. The sample photos and contact angle test photos are as follows Figure 6 shown.

[0051] 2. Analysis of wettability and unidirectional water conduction performance: BC@Cu(OH)2@CF was placed in a beaker filled with water, and it was observed that the hydrophobic surface of the material showed a mirror phenomenon due to its super hydrophobicity, while the hydrophilic surface was completely wetted. The BC@Cu(OH)2@CF sample was subjected to a unidirectional water conduction test. When the hydrophobic surface of the sample was the test surface, as the number of added water droplets (one drop was 10μL) increased, the small droplets condensed into large droplets and did not spread or penetrate; when the hydrophilic surface of the sample was the test surface, the water droplets directly entered the interior of the material but did not drip. As the number of water droplets increased, the wetted area became larger and larger. When the number reached a certain value, the material reached saturation. It can be seen that water droplets can only be transported from the hydrophilic side to the hydrophobic side, but not from the hydrophobic side to the hydrophilic side. The mirror phenomenon and unidirectional water conduction performance test experiments are shown below. Figure 7 and Figure 8 shown.

[0052] 3. Tilt plate method and hydrophobic performance test: In order to explore the influencing factor of BC@Cu(OH)2@CF's super hydrophobicity - the vapor deposition time, multiple sets of tilt plate parallel experiments were conducted and it was finally concluded that when the time is 3.5 minutes, the material can achieve super hydrophobicity. Figure 9 shown.

[0053] 4. Air permeability test: BC@Cu(OH)2@CF was fixed in the test device, and a paper strip was placed vertically on the right side of the device to test the air permeability of the material. At the beginning of the experiment, an air blower and a humidifier were used to blow air and spray steam at the left pipe of the device respectively. It can be observed that the originally vertical paper strip on the right side tilted at a certain angle due to the impact of the air flow, which shows that the material has good air permeability. Figure 10 shown.

[0054] 5. Water collection performance test: The water collection performance test of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF was carried out, and the water collection efficiency of CF, Cu(OH)2@CF and BC@Cu(OH)2@CF was 1.49 kg / (h·m 2 )、1.95kg / (h·m 2) and 2.66kg / (h·m 2 ), which proves that BC@Cu(OH)2@CF has a high water collection efficiency. Figure 11 and Figure 12 They are the water collection performance test experimental device and the water collection amount-time relationship diagram respectively.

[0055] 6. Reusability test: After recycling the BC@Cu(OH)2@CF sample 10 times, the water collection efficiency of each test was tested, proving that the water collection efficiency of the material is still good after 10 cycles. The water collection amount and water collection efficiency after 10 cycles are shown in Figure 2. Figure 13 shown.

[0056] 4. Practical Application:

[0057] Based on the excellent properties of the double-sided bisexual metal foam-based three-dimensional coupled water collection material, its application in air water collection devices can improve water collection efficiency. Figure 14 shown.

[0058] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A method for preparing a double-sided bifunctional metal foam-based three-dimensional coupled water-collecting material, characterized in that: The specific steps are as follows: Step 1: Immerse the copper foam in an ethanol solution for ultrasonic pretreatment; Step 2: Immerse the pretreated copper foam in a mixed solution of NaOH and K2S2O8, then take it out and soak it in deionized water continuously until the solution is clear, and then dry it to obtain hydrophilic copper foam; Step 3: After the polystyrene and dichloromethane solution are stirred and mixed, Dow Corning DC184 solution and its curing agent, and titanium dioxide powder are added in sequence, and after stirring to form a mixture, the mixture is evenly coated on a glass slide. After the surface is completely solidified, a hydrophobic coating is prepared; Step 4: Completely cover the hydrophilic copper foam on the hydrophobic coating, place it in an oven for vapor deposition, and then take it out to obtain a double-sided and biphilic foam metal-based three-dimensional coupled water-collecting material.

2. The method for preparing the double-sided bisexual metal foam-based three-dimensional coupled water-collecting material according to claim 1, characterized in that: The copper foam in step one and the glass slide in step three are the same size.

3. The method for preparing the double-sided bisexual metal foam-based three-dimensional coupled water-collecting material according to claim 1, characterized in that: The mass ratio of NaOH to K2S2O8 in step 2 is 3:

2.

4. The method for preparing the double-sided bisexual metal foam-based three-dimensional coupled water-collecting material according to claim 1, characterized in that: In step 3, the amount of polystyrene added is 1-3 g, the amount of dichloromethane solution added is 10-20 mL, and the amount of titanium dioxide powder added is 3-4 g.

5. The method for preparing the double-sided bisexual metal foam-based three-dimensional coupled water-collecting material according to claim 1, characterized in that: In step 3, the Dow Corning DC184 solution and its curing agent are vinyl-terminated polydimethylsiloxane and a platinum catalyst, respectively, and the mass ratio of vinyl-terminated polydimethylsiloxane to the platinum catalyst is 10:

1.

6. The method for preparing the double-sided bisexual metal foam-based three-dimensional coupled water-collecting material according to claim 1, characterized in that: In step 4, the oven temperature is 120° C. and the vapor deposition time is 3-4 minutes.

7. Application of a double-sided bisexual metal foam-based three-dimensional coupled water-collecting material prepared by the preparation method according to any one of claims 1 to 6, characterized in that: Double-sided and biphilic foam metal-based three-dimensional coupled water collection materials are used in air water collection devices to improve water collection efficiency.

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