An ant nest-like photothermal super-hydrophobic sponge and a preparation method and application thereof

Abstract

The application belongs to the field of functional materials and surface engineering, and particularly relates to an ant nest-like photo-thermal super-hydrophobic sponge as well as a preparation method and application thereof. The preparation method comprises the following steps: repeatedly soaking melamine sponge in anhydrous ethanol solution and drying; adding dopamine hydrochloride into a tris buffer solution to obtain a mixed solution by stirring, and then immersing the surface of the dried melamine sponge into the mixed solution and drying to obtain PDA@MS; adding PDMS and a curing agent into a cyclohexane solution to stir, then adding MWCNTs, MnO2 and CuO to stir to form a mixed solution, and then spraying the mixed solution on the surface of the PDA@MS and drying to obtain PMOS; and immersing the surface of the PMOS into a mixed solution of ethanol and deionized water containing PFOTES, and then taking out and drying. Through fine cross-scale multi-layer gap structure design, high mechanical durability, excellent light absorption capacity, efficient anti-icing, de-icing, interface evaporation and fresh water production in extreme environments are realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional materials and surface engineering, and particularly relates to an ant nest-like photothermal super-hydrophobic sponge as well as a preparation method and application thereof. BACKGROUND

[0002] Ice accretion poses serious economic and safety challenges. Especially in extreme environments, infrastructure (power cables, outdoor equipment, roads, aircraft and their devices) surfaces are prone to icing, leading to economic losses and safety hazards. Traditional active deicing methods, such as hot air, electric heating and mechanical deicing, while effective in solving some icing problems, are often high in energy consumption, high in cost and have a greater impact on the environment in extreme environments, thus making it difficult to be applied in extremely cold regions for a long time and economically. With the development of nanotechnology, passive deicing technology represented by super-hydrophobic surfaces has attracted widespread attention. Super-hydrophobic surfaces form air cushions by trapping air, reducing solid-liquid contact area, and delaying ice formation. However, in the polar high-humidity and low-temperature environment, water droplets can penetrate the air pocket into the micro-nano structure, causing the Cassie-Baxter state to Wenzel state transition, ice droplets firmly embedded in the surface structure, forming an interlocking effect, and thus reducing the ice prevention efficiency. In addition, although SLIPS (Slippery Liquid-Infused Porous Surface) performs well in reducing ice adhesion, it has poor wear resistance and limited effect in low-temperature environments.

[0003] To address the above problems, in recent years, photothermal super-hydrophobic surfaces and SLIPS have made some progress in photothermal deicing technology under sunlight. Photothermal super-hydrophobic surfaces can maintain an ice-free state under sunlight, overcoming some of the shortcomings of traditional super-hydrophobic surfaces, while the microstructure design and the introduction of photothermal materials play an important role in improving the super-hydrophobicity of the surface and the efficiency of photothermal conversion. However, the low radiation and extremely cold conditions in extreme environments still pose a great challenge to traditional photothermal materials and super-hydrophobic structures, and there is still a lack of integrated materials with efficient ice prevention and fresh water production functions in these areas.

[0004] The main disadvantages of the prior art are as follows:

[0005] 1. Insufficient mechanical durability

[0006] (1) Many existing super-hydrophobic materials are prone to failure under frequent external forces (such as friction, tape peeling, impact, etc.), resulting in a significant reduction in their hydrophobicity and functionality, and failing to meet long-term use requirements. (2) Lack of durability limits the widespread application of materials in extreme environments.

[0007] 2. Low light absorption efficiency

[0008] (1) Existing materials have low light absorption rates, especially in the visible and near-infrared ranges, making it difficult to fully utilize solar energy to achieve efficient heat conversion and de-icing. (2) This low light absorption rate results in low de-icing efficiency, especially in low-light-intensity environments.

[0009] 3. Low deicing efficiency and high energy consumption

[0010] (1) Traditional deicing technologies rely on external energy sources (such as electric heating or chemicals), which results in high energy consumption, high costs, and environmental pollution. (2) Some passive deicing materials can only delay ice formation but cannot effectively remove ice that has already formed.

[0011] 4. Limited interface evaporation performance

[0012] (1) Existing interface evaporation materials are prone to failure in extremely cold or high-salinity environments, making it difficult to achieve sustained and efficient water vapor escape. (2) Due to structural design constraints, the material suffers from large heat losses during the evaporation process, resulting in low efficiency.

[0013] 5. Poor environmental adaptability

[0014] (1) The performance of many materials rapidly degrades in salt spray, low temperature, or high humidity environments, making them difficult to apply in multiple scenarios. (2) Scaling or corrosion problems under high salt concentrations have not been effectively solved. Summary of the Invention

[0015] To address the shortcomings of existing technologies, the present invention innovatively develops an anthill-shaped photothermal superhydrophobic sponge, its preparation method, and its application. Through a sophisticated, multi-layered, cross-scale void structure design, the present invention achieves high mechanical durability and excellent light absorption capabilities, enabling efficient anti-icing, de-icing, interfacial evaporation, and freshwater production in extreme environments.

[0016] To achieve the above object, the present invention is implemented through the following technical solutions:

[0017] In a first aspect, the present invention provides a method for preparing an ant nest-shaped photothermal superhydrophobic sponge, comprising the following steps:

[0018] Step 1: Clean the melamine sponge (MS): soak the melamine sponge in anhydrous ethanol solution repeatedly and then dry it;

[0019] Step 2: Preparation of PDA@MS: dopamine hydrochloride was added to a tris buffer solution and stirred to obtain a mixed solution, and then the surface of the dried melamine sponge was immersed in the mixed solution and dried to obtain PDA@MS;

[0020] Step three: spray the blended solution: first add PDMS and its curing agent in cyclohexane solution and stir, then add MWCNTs, MnO2 and CuO and stir to form a mixed solution, then spray on the surface of PDA@MS and dry to obtain PDA@MWCNTs@MnO2@CuO@MS (referred to as PMOS);

[0021] Step four: reduce the surface energy of PMOS: immerse the surface of PMOS in a mixed solution of ethanol and deionized water containing PFOTES, then take out and dry.

[0022] As a further optimization scheme of the application, in step two, the mass-volume ratio of dopamine hydrochloride to tris buffer solution is 0.8-1.5g / 100ml, the pH value of the tris buffer solution is 8-10, the stirring time is 10-14h, and the drying temperature is 90-110℃.

[0023] Further preferably, the mass-volume ratio of dopamine hydrochloride to tris buffer solution is 1g / 100ml, the pH value of the tris buffer solution is 8, the stirring time is 12h, and the drying temperature is 100℃.

[0024] As a further optimization scheme of the application, in step three, the mass ratio of PDMS to its curing agent is 10:1, and the mass ratio of MWCNTs, MnO2 and CuO is (0.45-0.5):1:1. Further preferably, the mass ratio of MWCNTs, MnO2 and CuO is 0.45:1:1.

[0025] As a further optimization scheme of the application, in step three, the stirring time of PDMS and its curing agent is 0.8-1.5h, the stirring time after adding MWCNTs, MnO2 and CuO is 5-7h, the pressure of the spray gun during spraying is 0.3-0.5MPa, and the drying temperature is 50-70℃.

[0026] Further preferably, the stirring time of PDMS and its curing agent is 1h, the stirring time after adding MWCNTs, MnO2 and CuO is 6h, the pressure of the spray gun during spraying is 0.3MPa, and the drying temperature is 60℃.

[0027] As a further optimization scheme of the application, in step four, the volume ratio of deionized water to ethanol in the mixed solution is (8-10):1, the concentration of PFOTES in the mixed solution is 0.3-0.7g / 100ml, and the drying temperature is 70-90℃.

[0028] Further preferably, the volume ratio of deionized water to ethanol in the mixed solution is 9:1, the concentration of PFOTES in the mixed solution is 0.5g / 100ml, and the drying temperature is 80℃.

[0029] In a second aspect, the present application provides an ant nest-like photothermal superhydrophobic sponge, which has high mechanical durability and light absorption rate, and maintains superhydrophobicity after 200 times of tape peeling, friction test and 50 times of icing-deicing cycle, and has a light absorption rate of up to 98% in the wavelength range of 200-2500 nm.

[0030] In a third aspect, the present application provides an application of the ant nest-like photothermal superhydrophobic sponge in the field of ice prevention in extreme environments.

[0031] In a fourth aspect, the present application provides an application of the ant nest-like photothermal superhydrophobic sponge in the field of ice removal in extreme environments.

[0032] In a fifth aspect, the present application provides an application of the ant nest-like photothermal superhydrophobic sponge in the field of interfacial evaporation in extreme environments.

[0033] In a sixth aspect, the present application provides an application of the ant nest-like photothermal superhydrophobic sponge in the field of seawater desalination in extreme environments.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] (1) Compared with the prior art, the present application successfully prepares a superhydrophobic porous material (PMOS) with an ant nest-like nanostructure by attaching polydopamine and multi-walled carbon nanotubes to the surface of a melamine sponge, and realizes a technical breakthrough of efficient ice prevention, ice removal and fresh water production integration. PMOS combines micro / nano structure and high photothermal conversion performance, and has an absorption rate of up to 98% in the full waveband. Under single solar irradiation, the surface temperature of PMOS can be rapidly raised to 95℃ within 100 seconds, effectively promoting the rapid melting and detachment of ice. In addition, the superhydrophobic surface of PMOS forms an air cushion layer, further enhancing the active ice removal performance. Under 0.5 times solar radiation, PMOS can still remove sea ice with a thickness of 0.5 cm within 540 seconds. These characteristics effectively overcome the shortcomings of high energy consumption and large environmental burden of traditional active ice removal methods, and make PMOS have excellent energy-saving and environmental advantages in extremely cold environments.

[0036] (2) The PMOS of the present application also exhibits excellent interfacial evaporation performance, and is particularly suitable for polar fresh water production. Under one solar radiation, the interfacial evaporation rate of PMOS can reach 2.76 kg / m 2 ·h, and even under 0.5 times solar radiation, it can still maintain 2.35 kg / m 2 ·h. In addition, PMOS also has excellent mechanical durability, acid and alkali resistance and self-floating property, making it suitable for long-term use in extreme environments. In summary, the present application has broad application prospects in the fields of ice prevention / ice removal and seawater desalination in extreme environments, and is significantly superior to the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The preparation process of the ant nest-like photothermal super-hydrophobic sponge (PMOS) of the application is shown in the figure.

[0038] Figure 2 The SEM images of MS and PMOS at different magnifications and the EDS energy spectrum images of the corresponding elements C, O, Si, Mn and Cu are shown in the figure.

[0039] Figure 3 The Fourier infrared spectrum images of MS and PMOS are shown in the figure.

[0040] Figure 4 The super-hydrophobicity test images of the surfaces of various materials are shown in the figure. (a) WCA of various liquid droplets, including PH = 2, PH = 4, PH = 6, PH = 8, PH = 10, PH = 12, PH = 14, and WCA of milk, methyl orange, cola and fruit juice; (b) the shapes of liquid droplets on the surfaces of MS, PMS and PMOS captured by a high-speed camera.

[0041] Figure 5 The photothermal effect test images of the surface of PMOS are shown in the figure. (a) light absorption rate of PMOS in the wavelength range of ultraviolet, visible and near-infrared; (b) temperature change curve of MS, PMS and PMOS under one sunlight intensity; (c) temperature change curve of PMOS under 1, 1.5 and 2 light intensities; (d) temperature change curve of PMOS in 15 on-off light cycles.

[0042] Figure 6 The ice formation process images of liquid droplets on an aluminum plate and PMOS under a low temperature environment of -20℃ are shown in the figure.

[0043] Figure 7 The ice removal process images of PMOS on 2cm×2cm×0.5cm arctic sea ice under different light intensities (0.5sun, 0.8sun and 1sun) under a low temperature environment of -20℃ are shown in the figure.

[0044] Figure 8 The infrared spectrum images of the surface of the material evaporated by PMOS interface under one sunlight intensity are shown in the figure.

[0045] Figure 9 The interface evaporation characteristics of PMOS are shown in the figure. (a) relationship between evaporation mass and time under different light intensities (0.5sun, 0.8sun and 1sun); (b) interface evaporation rate of PMOS under different light intensities (0.5sun, 0.8sun and 1sun); (c) change of evaporation mass of PMOS on seawater with time in a 10-hour evaporation test; (d) change of evaporation rate of PMOS on seawater in each hour in a 10-hour evaporation test.

[0046] Figure 10 The contact angle change of the PMOS surface after 200 times of tape peeling experiment.

[0047] Figure 11 The contact angle change of the PMOS surface after 200 times of cycle.

[0048] Figure 12 The contact angle change of the PMOS surface after 50 times of freezing / thawing cycle.

[0049] Figure 13 The PMOS is subjected to 12d acid and alkali corrosion resistance test. Among them, (a): after 12d of acid and alkali corrosion of PH = 1, PH = 14, the surface light absorption rate test. (b): after 12d of acid and alkali corrosion of PH = 1, PH = 14, the surface contact angle change. DETAILED DESCRIPTION

[0050] In order to make the skilled in the art better understand the technical scheme of the present application, the preferred embodiments of the present application are described below in conjunction with specific examples, but it should not be understood as a limitation of the present application, only for example.

[0051] Example 1

[0052] Experimental materials and instruments

[0053] Table 1 main raw materials and reagents

[0054]

[0055] Table 2 main experimental instruments and equipment

[0056]

[0057]

[0058] The preparation process of the ant nest-like photo-thermal super-hydrophobic sponge (PMOS) is divided into three main steps.

[0059] First, a piece of 3cm×3cm×0.2cm melamine sponge is immersed in 100mL of anhydrous ethanol, and after repeated soaking three times, it is taken out and dried in a vacuum oven at 80℃. Then, 0.5 grams of dopamine hydrochloride is added to 50mL of tris buffer solution with pH value of 8, and placed on a magnetic stirrer for stirring for 12 hours. Subsequently, the dried melamine sponge surface is immersed in the mixed solution, taken out and dried in a vacuum drying oven at 100℃ for 6 hours, and finally PDA@MS (PMS) is obtained.

[0060] Second step spray: first, 0.5 g of PDMS and 0.05 g of curing agent were added into 100 mL of cyclohexane solution, after stirring for 1 h, 0.09 g of MWCNTs, 0.2 g of MnO2 and 0.2 g of CuO were added into the above mixed solution, and after stirring for 6 h, a spray solution was formed. The spray solution was added to the spray tank, the spray gun pressure was adjusted to 0.3 MPa, and the nozzle distance from PDA@MS was about 15 cm for spraying. The sprayed PDA@MS was taken out after drying in a 60°C vacuum drying oven for 1 hour, and PDA@MWCNTs@MnO2@CuO@MS (PMOS) was obtained.

[0061] The third step is to reduce the surface energy of PMOS: first, a mixed solution of deionized water and ethanol with a total volume of 100 mL was prepared; 0.5 g of PFOTS solution was added, and the solution was stirred for 3 h. Subsequently, the PMOS surface was immersed in the above mixed solution. It was taken out and placed in a vacuum drying oven at 80°C for 3 hours, and then taken out.

[0062] Experimental example: test and characterization

[0063] The surface morphology and element distribution were characterized by field emission scanning electron microscope Zeiss Sigma300 equipped with energy dispersive spectrometer (EDS). Fourier transform infrared (FTIR) spectra were collected on Nexus 670 spectrometer, ranging from 4000-400 cm -1 -1. Optical absorption spectra were collected on Shimadzu UV3600 ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometer.

[0064] Photo-thermal conversion property test

[0065] The temperature change of PMOS was tested at different solar intensities by using a xenon lamp to simulate a natural light source.

[0066] Anti-icing performance test

[0067] Under the ambient humidity of 30±2%, the static anti-icing performance was evaluated by the freezing time of water droplets. The time for water droplets to change from liquid phase to solid phase was defined as the delay icing time. First, the bare aluminum plate and PMOS were placed in a low temperature chamber at -20°C, and then 20 μL of liquid droplets were added on top of them using a needle tube, and the delay icing was observed.

[0068] Photo-thermal deicing performance test

[0069] First, the material was placed inside a low temperature chamber at -20°C and relative humidity of 30±2%, and the material was given an inclination angle of 30°. Under the simulated sunlight irradiation above the material, the photo-thermal deicing performance was evaluated by the time for the ice block to slide off the surface. Different simulated sunlight intensities (0.5 kW / m 2 , 0.8 kW / m 21 kW / m 2 ) generated by a xenon lamp (CEL-PE300L-3A).

[0070] Interfacial evaporation property test

[0071] Under the condition of ambient temperature 25±2℃, relative humidity 30±2%, the interfacial evaporator (PMOS) was placed in a beaker containing 100 mL of seawater. Then the beaker was placed on the surface of the balance, and the xenon lamp was placed directly above the beaker, and the interfacial evaporation rate of the interfacial evaporator (PMOS) was tested by adjusting the intensity of the xenon lamp to simulate natural light. At the same time, the changes of the infrared spectrum of the surface of the interfacial evaporator under one solar intensity were observed.

[0072] Mechanical durability test

[0073] Adhesion with 500g weight tape, 200 cycles of peeling experiment, 40 tests as a group of experiments, through the contact angle measuring instrument to detect whether the PMOS surface has super-hydrophobicity after each group of tape peeling test (select five positions on the surface for testing when measuring the contact angle, and take the average value). Secondly, adhesion with 500g of sandpaper, 200 cycles of friction experiment, also 40 tests as a group of experiments, through the contact angle measuring instrument to detect whether the PMOS surface has super-hydrophobicity after each group of tape peeling test.

[0074] Acid and alkali corrosion resistance

[0075] PMOS was immersed in strong acid and strong alkali solution with PH=1 and PH=14 respectively, and the acid and alkali corrosion resistance test was carried out for 12 days. By comparing the ultraviolet, visible and near infrared light absorption rate spectrum of the PMOS after acid corrosion, the PMOS after alkali corrosion, and the uncorroded PMOS, the influence of acid and alkali corrosion on the absorption rate was judged. And by testing the contact angle change of the surface after acid and alkali corrosion, whether the microstructure of the surface was corroded and damaged was judged

[0076] Mechanism of preparation process of photothermal super-hydrophobic sponge

[0077] Figure 1The synthesis process of superhydrophobic sponge is demonstrated. PDA can undergo self-polymerization reaction under alkaline conditions, forming stable covalent bonds. This process generates o-benzoquinone structure from dopamine monomer of PDA, forming covalent bonds with the amino group on melamine, further enhancing its adhesion and chemical stability. Surface roughness and low surface energy are two key factors for superhydrophobicity. Generally, larger surface roughness and lower surface energy are conducive to obtaining higher superhydrophobicity. Using a combination of micron-sized particles and nano-sized particles can achieve the appropriate roughness to create a superhydrophobic surface. Large particles (micron-sized) in the dispersion liquid are first deposited on the convex parts or hole edges of the sponge surface by spraying due to gravity or inertia. Small particles (nano-sized) subsequently fill the gaps between micron-sized particles or the nanopores of the sponge due to stronger Brownian motion, forming a secondary structure. In addition, the PDA modification layer provides abundant hydroxyl (-OH) groups, which can react with the silanol groups formed in the dehydration condensation reaction of PFOTES, forming solid Si-O-C covalent bonds, firmly connecting PFOTES to the polydopamine modification layer, thereby enhancing its hydrophobicity and reducing surface energy.

[0078] Composition and structure characterization of PMOS surface

[0079] Figure 2 The surface morphology changes during the PMOS manufacturing process were studied. The initial melamine sponge surface is smooth, with clear texture and clear pores, having a three-dimensional cross-linked porous network structure. Low surface free energy nanomaterials can be uniformly attached to its skeleton without damaging the structure. Due to the inherent adhesion, PDA acts as a connecting layer between CuO, MnO2, and MWCNTs particles, which are firmly adhered to the sponge skeleton. Therefore, PMOS is designed and generated to have a stable rough structure. In addition Figure 3 The formation of chemical bonds was determined by analyzing the position of the characteristic absorption peaks. The results show that the peaks at 1256.2 cm -1 and 1332.8 cm -1 indicate that C-N bonds have been produced. At the same time, the peak at 1153.4 cm -1 represents the formation of Si-O-C covalent bonds. Therefore, the spectrum shows the existence of C-N and Si-O-C covalent bonds, supporting the successful bonding of polydopamine with melamine sponge PFOTES.

[0080] Superhydrophobic properties of PMOS surface

[0081] Figure 4To verify the sponge's superhydrophobic properties, we placed 20μL droplets of liquids with pH values ​​of 2, 4, 6, 8, 10, 12, or 14 on the surface of a PMOS substrate. We measured the WCA of the PMOS surface using a contact angle meter, showing that the contact angles consistently exceeded 150°. We then added 20μL of milk, methyl orange, cola, and juice to the PMOS surface, demonstrating that the contact angles consistently exceeded 150°. Furthermore, a high-speed camera captured the shape of the droplets on the surfaces of a MS, PMS, and PMOS substrate. The results showed that the MS exhibited hydrophilicity with a contact angle of 0, the PMS exhibited hydrophobicity with a contact angle of 137°, and the PMOS exhibited superhydrophobicity with a contact angle of 154.5°.

[0082] PMOS surface light-to-heat conversion characteristics

[0083] The photothermal conversion property is crucial for both de-icing and interface evaporation. Figure 5 As shown, compared to melamine sponge (MS), superhydrophobic-coated melamine sponge (PMOS) exhibits a high absorptivity of 98% in the UV-Vis-NIR range. The high light absorption of multi-walled carbon nanotubes (MWCNTs) improves photothermal conversion efficiency, allowing for rapid temperature rise, thus facilitating de-icing. First, we compared the temperature evolution of MS, PMS, and PMOS over time under one sun intensity. The results showed that the photothermal conversion properties of the MS surface were gradually enhanced after layer-by-layer modification. Secondly, we investigated the photothermal conversion properties of the PMOS by adjusting the light intensity. With increasing light intensity, the equilibrium surface temperature increased. At one sun intensity, the equilibrium surface temperature was 95°C. When increased to two suns, the equilibrium temperature reached nearly 140°C. Furthermore, to investigate the photothermal stability of the PMOS, we found that after 15 on / off cycles under one sun intensity, the surface temperature remained around 95°C, demonstrating excellent photothermal stability.

[0084] Delayed icing test of PMOS

[0085] Figure 6 The results show that at -20°C, the droplets on the aluminum plate solidified within a few tens of seconds, while the droplets on the PMOS surface took 5400 seconds to fully solidify. This indicates that the PMOS exhibits excellent delayed freezing properties. This is primarily due to the micro-nanostructure on the surface of the photothermal superhydrophobic sponge trapping air to form an "air buffer layer," effectively reducing the contact area between the droplet and the sponge surface. This increases the surface's thermal resistance and effectively delays the freezing of the droplet.

[0086] PMOS de-icing characteristic test

[0087] Figure 7 As shown in the figure, inside the low temperature chamber at -20℃ and relative humidity 30±2%, different simulated sunlight intensities (0.5kW / m 2 , 0.8kW / m 2 , 1kW / m 2 ) irradiated 0.5 cm of Arctic sea ice. The results showed that at a single solar intensity, the Arctic sea ice could be completely removed within 300 seconds, and even at a low irradiance of 0.5 solar intensities, the Arctic sea ice could be completely removed within 540 seconds, demonstrating excellent photothermal deicing properties.

[0088] PMOS interface evaporation characteristics

[0089] PMOS has sufficient vapor escape channels and light-to-heat conversion properties, making it an excellent choice for solar interface evaporators. First, we analyze the infrared spectrum of the PMOS interface evaporation material surface under a certain sunlight intensity ( Figure 8 ). When the xenon lamp is turned on, the temperature of the photothermal layer rises rapidly and reaches an equilibrium temperature of 60°C within 60s; when the lamp is turned off, the temperature drops rapidly and returns to its initial state within 5 minutes. Infrared images show that the heating and cooling processes are mainly concentrated on the upper surface of the sponge. Such a significant local heating effect not only provides a higher surface temperature, but also significantly improves the interface evaporation efficiency. In addition, for the low-intensity polar environment, the experiment also explored the interface evaporation rate of PMOS under 0.5 and 0.8 solar intensities. Figure 9 The results show that the evaporation rate of PMOS reaches 2.35 kg / m at 0.5 sun intensity. 2 h, increases to 2.47 kg / m at 0.8 suns 2 ·h, which shows that PMOS has good interface evaporation performance even under low temperature and low irradiance conditions. In order to meet the demand for fresh water in extreme environments, we used photothermal interface evaporation materials to conduct evaporation experiments on seawater after sea ice melted. Figure 9 As shown, under 1 sun intensity, the evaporation rate of the material gradually increases within the first 3 hours and then stabilizes. This process is due to the gradual increase in surface temperature and the establishment of thermal equilibrium. Simultaneously, the opening of water migration channels and the continuous replenishment of surface water further promote evaporation. Once the photothermal conversion and water supply reach a dynamic equilibrium, the evaporation rate remains stable.

[0090] Mechanical durability of PMOS

[0091] like Figure 10 and 11After 200 cycles of tape peeling and rubbing, the contact angle of the droplet on the PMOS surface remained around 150°, showing good mechanical durability. This is mainly due to the fact that each micro- or nano-structured unit independently withstands external forces during friction, and the stress dispersion mechanism significantly reduces the overall wear level of the material and enhances wear resistance.

[0092] Ice-melting cycle test of PMOS

[0093] Figure 12 To evaluate the ice-melting effect of PMOS and its reusability, a 50-cycle ice-melting test was conducted. The results show that after 50 cycles, the contact angle on the PMOS surface decreases slightly but remains around 150°, which ensures excellent photothermal ice-melting performance of the material during the day.

[0094] Corrosion resistance of PMOS

[0095] Figure 13 The PMOS remains super-hydrophobic after being immersed in acidic and alkaline solutions for 12 days, and its full-band light absorption remains almost unchanged, showing excellent chemical stability. This stability is mainly due to the protective effect of the surface air film.

[0096] In summary, the present application solves multiple key problems in the prior art through innovative design concepts and material structures, and has obvious advantages in efficiency, energy consumption, ease of operation, mechanical durability, etc. The following are the main technical advantages and beneficial effects of the present application compared to the prior art:

[0097] 1. Improve mechanical durability and extend service life

[0098] Existing super-hydrophobic materials often lose their hydrophobicity after long-term use or external force, leading to a decrease in material performance. Especially in the process of frequent ice-melting and ice-melting cycles, traditional materials are easily damaged and cannot maintain their functionality for a long time.

[0099] (1) Technical advantage: The present application designs a composite material with a cross-scale gap structure, which has stronger mechanical durability. After 200 cycles of tape peeling, rubbing tests and 50 cycles of ice-melting, the material can still maintain its excellent super-hydrophobicity, significantly improving the long-term performance of the material.

[0100] (2) Beneficial effect: The durability of the material is greatly improved, reducing the frequency of material replacement and maintenance costs, and allowing it to work stably in extreme environments for a long time.

[0101] 2. Improve light absorption rate and enhance ice-melting efficiency

[0102] Traditional deicing materials often cannot effectively utilize low-intensity solar radiation, resulting in poor deicing performance in winter or insufficient light environments. Especially in low-temperature conditions, external energy consumption is large, the deicing process is slow, and energy is wasted.

[0103] (1) Technical advantages: The light absorption rate of the material reaches 98%, especially the absorption performance in the wavelength range of 200-2500 nm is greatly improved, which can still quickly convert solar energy under low light intensity, thereby accelerating the deicing process.

[0104] (2) Beneficial effects: The material can achieve efficient deicing even in weak sunlight, and can extend the icing time to 5400 seconds at-20℃, saving energy consumption, without the need for additional electricity or chemical energy, reducing the use cost and environmental pollution.

[0105] 3. Efficient interfacial evaporation performance, suitable for complex environments

[0106] Existing materials often have low evaporation efficiency and large heat loss in interfacial evaporation applications, especially in high-salinity or extremely cold environments. Most materials fail easily in seawater or low-temperature environments, making it difficult to maintain a stable evaporation process.

[0107] (1) Technical advantages: The composite material of the present application realizes efficient interfacial evaporation through an optimized water vapor escape channel. The evaporation rate of the material can reach 2.76 kg / m 2 ·h, greatly improving the efficiency and application range of interfacial evaporation.

[0108] (2) Beneficial effects: The present application provides an efficient seawater desalination solution, and solves the problem of low interfacial evaporation efficiency in extremely cold environments, and can work stably under various extreme conditions, suitable for seawater desalination, deicing and environmental evaporation, etc. Field.

[0109] 4. Environmental protection and energy efficiency improvement

[0110] Existing deicing and anti-icing technologies mostly rely on electric heating, chemical deicing agents, etc. These methods not only have high energy consumption, but also pollute the environment, especially chemical deicing agents may cause secondary pollution to water, soil and other environments.

[0111] (1) Technical advantages: The present application can realize efficient deicing under low energy consumption conditions through innovative super-hydrophobic material design, and does not need to use chemical deicing agents, avoiding environmental pollution.

[0112] (2) Beneficial effects: The present application greatly reduces energy consumption and environmental impact, meets the needs of sustainable development, and provides a green and environmentally friendly deicing and evaporation solution.

[0113] 5. Simple processing and operation

[0114] Existing super-hydrophobic materials usually have complex processing procedures, require high-precision control and multiple processing steps, resulting in high production costs and difficult operation. For industrial applications, the simplicity of material processing and operation is crucial.

[0115] (1) Technical advantages: The composite material of the present application adopts a simple and efficient production process, which is easy to mass-produce and scale up. At the same time, the use of the material does not require complex operation and maintenance, making it more convenient in practical application.

[0116] (2) Beneficial effects: The present application can reduce the production cost of the material, improve the production efficiency, make it suitable for large-scale industrial application, reduce the operation complexity, and facilitate popularization and popularization.

[0117] The above is only the preferred embodiment of the present application, it should be pointed out that the above preferred embodiment should not be regarded as limiting the present application, the protection scope of the present application should be limited by the scope defined in the claims. For ordinary skilled in the art, without departing from the spirit and scope of the present application, a number of improvements and refinements can also be made, which should be regarded as the protection scope of the present application.

Claims

1. A method for preparing an ant nest-shaped photothermal superhydrophobic sponge, characterized in that: The following steps are involved: Step 1: Clean the melamine sponge: Soak the melamine sponge in anhydrous ethanol solution repeatedly and then dry it; Step 2: Preparation of PDA@MS: dopamine hydrochloride was added to a tris buffer solution and stirred to obtain a mixed solution, and then the surface of the dried melamine sponge was immersed in the mixed solution and dried to obtain PDA@MS; Step 3: Spraying the blended solution: PDMS and its curing agent are first added to the cyclohexane solution and stirred. MWCNTs, MnO2, and CuO are then added and stirred to form a mixed solution. The solution is then sprayed on the PDA@MS surface and dried to obtain PMOS. Step 4: Reduce the surface energy of PMOS: Immerse the PMOS surface in a mixed solution of ethanol and deionized water containing PFOTES, and then take it out and dry it.

2. The method for preparing the ant nest-shaped photothermal super-hydrophobic sponge according to claim 1, wherein: In step 2, the mass volume ratio of dopamine hydrochloride to tris buffer solution is 0.8-1.5 g / 100 ml, the pH value of the tris buffer solution is 8-10, the stirring time is 10-14 h, and the drying temperature is 90-110° C.

3. The method for preparing the ant nest-shaped photothermal super-hydrophobic sponge according to claim 1, wherein: In step 3, the mass ratio of PDMS to its curing agent is 10:1, and the mass ratio of MWCNTs, MnO2 and CuO is (0.45-0.5):1:

1.

4. The method for preparing the ant nest-shaped photothermal super-hydrophobic sponge according to claim 1, wherein: In step 3, the stirring time of PDMS and its curing agent is 0.8-1.5 hours, and the stirring time after adding MWCNTs, MnO2 and CuO is 5-7 hours. The pressure of the spray gun during spraying is 0.3-0.5 MPa, and the drying temperature is 50-70°C.

5. The method for preparing the ant nest-shaped photothermal super-hydrophobic sponge according to claim 1, wherein: In step 4, the volume ratio of deionized water to ethanol in the mixed solution is (8-10):1, the concentration of PFOTES in the mixed solution is 0.3-0.7 g / 100 ml, and the drying temperature is 70-90° C.

6. The ant nest-shaped photothermal superhydrophobic sponge prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The sponge has high mechanical durability and light absorption rate. It remains superhydrophobic after 200 tape peeling and friction tests and 50 icing-deicing cycles, and its light absorption rate in the wavelength range of 200-2500nm is as high as 98%.

7. Application of the ant nest-shaped photothermal superhydrophobic sponge according to claim 6 in anti-icing in extreme environments.

8. Application of the ant nest-shaped photothermal superhydrophobic sponge according to claim 6 in deicing under extreme environments.

9. Application of the ant nest-shaped photothermal superhydrophobic sponge according to claim 6 in interfacial evaporation under extreme environments.

Images