A double-parent slip water-collecting surface based on lubricating interface capillary coupling driving and a preparation method thereof

Abstract

The present application relates to a double parent slip water collecting surface and a preparation method thereof, and in particular to a double parent slip water collecting surface based on lubricating interface capillary coupling driving and a preparation method thereof. To solve the problems of the prior art that droplet migration in the water collecting surface depends on size triggering, droplet migration efficiency is low, surface updating efficiency is low, or migration driving force is insufficient, the double parent slip water collecting surface based on lubricating interface capillary coupling driving comprises a slip region and a plurality of droplet collecting regions arranged on a substrate surface; the slip region comprises a slip layer and a lubricating layer covering the surface of the slip layer; the slip layer comprises a cross-linked polymer network and an oil phase lubricant distributed in the cross-linked polymer network; the plurality of droplet collecting regions are dispersed in the slip region to perform directional aggregation and discharge of droplets; and the water contact angle of the droplet collecting region is smaller than the water contact angle of the slip region.

Description

Technical Field

[0001] This invention relates to a biphile slip-collecting surface and its preparation method, specifically to a biphile slip-collecting surface driven by capillary coupling at a lubrication interface and its preparation method. Background Technology

[0002] With global population growth and industrial development, the problem of freshwater scarcity is becoming increasingly serious. The atmosphere contains abundant water resources in the form of water vapor or fog droplets; therefore, obtaining freshwater through atmospheric water harvesting technology is considered a potential solution to the freshwater shortage problem. Among these, atmospheric water harvesting based on condensation mechanisms has attracted widespread attention due to its simple structure and high scalability.

[0003] In atmospheric water harvesting based on condensation mechanisms, functional interfaces are typically used as the water collection surface. Droplets undergo nucleation, growth, merging, and detachment on this surface. Traditional water collection surfaces usually rely on gravity or structural actuation for droplet detachment, requiring droplets to grow to a relatively large size before falling off. During this process, numerous tiny droplets remain on the surface for extended periods, occupying nucleation sites and reducing surface renewal efficiency, thus limiting the overall water collection performance of the functional interface. To improve droplet detachment behavior, researchers have developed various functional interfaces, such as superhydrophobic surfaces, lubricating liquid-wetted porous surfaces (SLIPS), and hydrophobic-philic composite surfaces. These interfaces can reduce droplet adhesion or provide some migration driving force. However, existing functional interfaces generally require droplet size to reach a certain threshold before migration is triggered, resulting in a significant time lag between droplet nucleation and migration.

[0004] Therefore, how to provide a continuous driving force in the early stages of droplet formation, enabling droplets to interact and migrate at the microscale stage, thereby improving the renewal efficiency of the water collection surface, is a key issue that urgently needs to be addressed in the current design of atmospheric water collection interfaces. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of droplet migration on water collection surfaces that depend on size triggering, have low droplet migration efficiency, low surface renewal efficiency, or insufficient migration driving force in the prior art. The invention provides an amphiphilic sliding water collection surface driven by capillary coupling at a lubricating interface and its preparation method to achieve dynamic coupling migration of droplets and efficient water collection.

[0006] The inventive concept of this invention is to construct a droplet collection region on a slip layer containing an oil-phase lubricant. This allows droplets to induce the formation of lubricating ridges within the slip layer, generating capillary coupling driving forces. Simultaneously, the trapping effect of the droplet collection region enables the directional aggregation and discharge of droplets, thus forming a continuously and dynamically renewed water collection interface. This achieves a mechanism shift from "static growth detachment" to "dynamic interface transport," significantly improving atmospheric water collection efficiency.

[0007] To achieve the above objectives and complete the above inventive concept, the technical solution provided by this invention is as follows:

[0008] A biphile sliding water collection surface driven by capillary coupling at a lubrication interface is characterized by: comprising a substrate and sliding regions and multiple droplet collection regions disposed on the substrate surface; the sliding regions include a sliding layer disposed on the substrate surface and a lubrication layer covering the surface of the sliding layer; the sliding layer includes a cross-linked polymer network and an oil-phase lubricant distributed in the cross-linked polymer network, the cross-linked polymer network being capable of adsorbing, storing, and releasing the oil-phase lubricant; the lubrication layer is composed of the oil-phase lubricant; the multiple droplet collection regions are dispersed in the sliding regions for directional aggregation and discharge of droplets; the water contact angle of the droplet collection regions is smaller than the water contact angle of the sliding regions.

[0009] Furthermore, the water contact angle of the slip region is 95°~99°;

[0010] The water contact angle of the droplet collection area is 0°~80°.

[0011] Furthermore, the thickness of the lubricating layer is 2~20 μm;

[0012] The droplet collection area is configured as a strip structure, and the surface is configured as a metal micro-nano composite structure; the width of the strip structure is 100~600 μm, and the spacing between adjacent strip structures is 0.5~2 mm.

[0013] Furthermore, the thickness of the lubricating layer is 2~5 μm;

[0014] The width of the strip-shaped structure is 260~400μm;

[0015] The substrate is any one of metal, glass, ceramic, silicon wafer or polymer;

[0016] The metal is one of aluminum, aluminum alloy, copper, stainless steel, titanium, or titanium alloy;

[0017] The metal micro / nano composite structure is a nickel or copper metal micro / nano composite structure.

[0018] Meanwhile, the present invention also provides a method for preparing the above-mentioned amphiphilic sliding water-collecting surface driven by capillary coupling of the lubrication interface, which is characterized by:

[0019] Step S0: Prepare the substrate according to the design requirements and pre-treat its surface; then determine whether the substrate material is metal. If yes, proceed to step S1; otherwise, prepare a conductive layer on the substrate surface and then proceed to step S1.

[0020] Step S1, preparation of slip layer: The prepolymer and curing agent are mixed and crosslinked to obtain a polymer precursor. Then, the oil phase lubricant is mixed evenly with the polymer precursor to obtain a lubricant mixture. The lubricant mixture is evenly coated on the substrate surface and heated evenly to cure it, forming a slip layer.

[0021] Step S2, droplet collection area construction: According to the preset pattern of the droplet collection area, remove the slip layer of the corresponding area on the substrate surface, and process the droplet collection area on the substrate surface of the corresponding area;

[0022] Step S3, underwater competitive wetting treatment: After cleaning the sample obtained in step S2, the droplet collection area is wetted with aqueous phase, and then a lubricating layer is prepared on the surface of the slip layer to obtain an amphiphilic slip water collection surface driven by capillary coupling of the lubrication interface.

[0023] Further, in step S1, the lubricant is one or a mixture of two or more of silicone oil, fluorosilicone oil, perfluoropolyether oil, and mineral oil;

[0024] The prepolymer is one or a mixture of two or more of polydimethylsiloxane prepolymer, polyurethane prepolymer, fluorosilicone resin prepolymer, or acrylate prepolymer; the curing agent is a crosslinking agent compatible with the prepolymer.

[0025] Further, in step S1, the coating thickness of the lubricant mixture is 10~20μm, and the heating temperature is 60~100℃;

[0026] The mass ratio of the prepolymer to the curing agent is 4~20:1, and the mass ratio of the lubricant to the polymer precursor is 0.2~1:1;

[0027] The prepolymer is a polydimethylsiloxane prepolymer, and the curing agent is one of a hydrogen-containing silicone oil crosslinking agent or a platinum-catalyzed addition-type silicone rubber curing agent.

[0028] Furthermore, step S2 specifically includes:

[0029] 2.1 Place the sample processed in step S1 into a femtosecond laser processing system, and perform laser ablation on the slip layer in the corresponding area of ​​the substrate surface according to the preset pattern of the droplet collection area to remove the slip layer in the corresponding area of ​​the substrate surface;

[0030] 2.2 Electrodeposition is performed on the pre-designed pattern area of ​​the ablated sample to form a metal micro / nano composite structure, which serves as a droplet collection area;

[0031] Step S3 is as follows:

[0032] After cleaning the samples obtained in steps S3.1 and S2, they are completely immersed in deionized water so that the droplet collection area is wetted by the aqueous phase.

[0033] Step S3.2: Then, oil-phase lubricant is slowly injected into the water-solid interface on the surface of the slip layer so that the oil-phase lubricant covers the slip region. The sample is taken out from the deionized water and then left to stand for at least 6 hours to form a lubricating layer on the surface of the slip region, thus obtaining an amphiphilic slip water collecting surface driven by capillary coupling of the lubricating interface.

[0034] Furthermore, in step S1, the conductive layer is prepared by chemical plating, magnetron sputtering, or gold sputtering;

[0035] In step S2, the cathode in the electrodeposition is the metal substrate of the sample or a pre-formed conductive layer, and the anode is nickel or copper.

[0036] The current density for electrodeposition is 0.5~2 A / dm³. 2 The electrodeposition time is 0.1~2 h.

[0037] Furthermore, in step S0, the pretreatment involves cleaning and polishing the substrate surface to make it smooth and free of contaminants.

[0038] In step S1, the prepolymer is a polydimethylsiloxane prepolymer, the lubricant is silicone oil, the curing agent is a hydrogen-containing silicone oil crosslinking agent, and the coating thickness of the lubricant mixture is 20 μm.

[0039] Compared with the prior art, the present invention has the following beneficial technical effects:

[0040] 1. This invention constructs an interface structure in which the slip region and the droplet collection region work synergistically. The lubrication layer enables adjacent droplets to migrate and merge under the capillary coupling driving force of the lubrication ridge, thereby reducing the dependence of droplets on size-triggered detachment. Simultaneously, under the synergistic effect of the slip region and the droplet collection region, droplets can migrate continuously and directionally aggregate towards the droplet collection region, thus achieving surface renewal. This invention realizes a novel droplet control mechanism at the interface physical level, significantly improving surface renewal efficiency and water collection performance.

[0041] 2. In the present invention, the method for preparing a biphile sliding water collection surface driven by capillary coupling of the lubrication interface is to form a sliding layer containing lubricant by coating and curing, and to construct the droplet collection area by laser processing, electrodeposition and underwater competitive wetting treatment. The structure has strong design flexibility and is suitable for different application scenarios such as planar substrates, metal substrates and heat exchange fins. Attached Figure Description

[0042] Figure 1 This invention provides an example of a mesophilic sliding water-collecting surface driven by capillary coupling of a lubricating interface. During the process of forming a lubricating ridge structure after the droplet contacts the lubricating layer, the three-phase contact area of ​​the droplet, lubricating layer, and air undergoes local interface deformation at 0s (I), 0.2s (II), and 1s (III), respectively, and the corresponding magnified optical images of the whole and the corresponding local areas.

[0043] Figure 2 This is a comparison of the droplet contact angles in the sliding region and the droplet collection region at a diameter of 5 μL during the water collection process of the first embodiment of the amphiphilic sliding water collection surface driven by capillary coupling of the lubrication interface according to the present invention.

[0044] Figure 3 This is an example of an amphiphilic sliding water collection surface driven by capillary coupling of a lubricating interface according to the present invention. During the water collection process, when droplets approach each other in the sliding region until they merge, the optical images are taken at 0s (I), 0.32s (II), 0.56s (III), and 0.88s (IV).

[0045] Figure 4 This is a schematic flowchart of Example 1 of the method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling of the lubrication interface according to the present invention.

[0046] Figure 5 The images show the trajectory of droplets at 0s (I), 2s (II), 4s (III), 6s (IV), and 8s (V) during the water collection process of the amphiphilic sliding water collection surface driven by capillary coupling based on the lubricating interface in Embodiment 1 of the present invention.

[0047] Figure 6 This is a schematic diagram of step 3) in Example 1 of the Amphiphilic Sliding Water Collecting Surface Driven by Capillary Coupling of Lubricating Interface of the present invention; wherein, A is the sample after laser ablation and B is the sample after electrodeposition.

[0048] Figure 7 This is a comparison chart of water collection volume between Example 1 of the amphiphilic sliding water collection surface driven by capillary coupling of the lubrication interface of the present invention and a traditional wettable surface.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Substrate, 2-Slip region, 3-Droplet collection region. Detailed Implementation

[0051] Example 1

[0052] This invention discloses an amphiphilic sliding water collection surface driven by capillary coupling at a lubrication interface, comprising a substrate 1 and a sliding region 2 and a droplet collection region 3 disposed on the surface of the substrate 1. The sliding region 2 includes a stable sliding layer covering the surface of the substrate 1 and a lubrication layer composed of lubricant covering the surface of the sliding layer, forming a low-adhesion liquid interface where droplets exhibit low contact resistance and can migrate freely. When a droplet forms in the sliding region 2, a three-phase contact area is formed between the droplet, the lubrication layer, and the air. Due to the interfacial tension between the droplet and the lubricant, local interfacial deformation of the lubricant occurs at the three-phase contact area, causing the lubricant to locally arch or accumulate near the droplet edge, thereby forming a ring-shaped or locally ring-shaped lubricant ridge structure around the droplet. This lubricant ridge structure is called a lubrication ridge structure. Figure 1 As shown, the lubrication ridge structure is a localized interfacial deformation of the lubrication layer caused by the interfacial tension of the droplet.

[0053] Multiple droplet collection regions 3 are provided in the sliding region 2 to achieve directional aggregation and discharge of droplets. The droplet collection regions 3 have a stronger droplet trapping ability than the sliding region 2, causing droplets to preferentially move and aggregate towards the region during migration in the sliding region 2. The droplet collection regions 3 can form a micro-nano composite structure through electrodeposited metal microstructures, enabling them to exhibit preferential wetting or preferential trapping characteristics for droplets in an oil-water coexisting environment. The droplet collection regions 3 have a stronger droplet trapping ability than the sliding region 2, and their water contact angle is smaller than that of the sliding region 2. Preferably, the water contact angle of the droplet collection regions 3 is between 0° and 80°. In this embodiment, the water contact angle of the droplet collection regions 3 is approximately 53°, and the water contact angle of the sliding region 2 is approximately 97.5°. Figure 2 As shown, the droplet collection region 3 has a stronger droplet-capturing ability than the slip region 2, and can form a wettability difference with the slip region 2, thereby guiding droplets to aggregate towards the droplet collection region 3. During operation, with the dynamic distribution or local migration of lubricant on the water collection surface, the droplet collection region 3 can gradually expose a high surface energy metal micro-sodium composite structure, thereby further enhancing the wetting and aggregation behavior of droplets. The droplet collection region 3 is not only used to capture droplets, but also to form a continuous water film when certain structural dimensions are met.

[0054] The droplet collection region 3 of this invention is preferably a strip-shaped metal micro / nano composite structure with a width of 100-600 μm and a spacing of 0.5-2 mm between adjacent strip-shaped structures. When the width of the droplet collection region 3 is small, droplets entering this region tend to exist in discrete droplet form and are affected by the pinning effect of the solid-liquid contact line; however, when the width of the droplet collection region 3 is too large, it will compress the width of the sliding region 2, affecting the rapid migration of droplets in the sliding region 2. Preferably, the width is not less than 260 μm but not more than 400 μm. By controlling the width of the strip-shaped structure, droplets entering the droplet collection region 3 can spread and connect with each other on the surface of the micro / nano composite structure, thereby transforming from a discrete droplet state into a continuous water film. The continuous water film can serve as a liquid phase collection interface for subsequent migrating droplets, allowing droplets to preferentially contact the existing water film with liquid, thereby promoting continuous aggregation and discharge of droplets and improving the continuous transport capacity of the droplet collection region 3.

[0055] The aforementioned biparental sliding water-collecting surface achieves new droplet control mechanisms during water collection, including an interface deformation-driven droplet interaction mechanism, a droplet non-contact coupling migration mechanism, and an interface self-renewal continuous water collection mechanism.

[0056] (1) Droplet interaction mechanism driven by interface deformation;

[0057] When the lubricating ridges around adjacent droplets overlap, approach, or disturb each other, the surface curvature of the lubricating layer changes, creating a capillary pressure difference between adjacent droplets. This generates a capillary coupling driving force that brings the droplets closer together. Thus, droplets can undergo capillary coupling before direct contact, i.e., mutual attraction, and gradually migrate and merge, such as... Figure 3 As shown. Compared to traditional migration modes that rely on droplet contact or gravity triggering, this invention can establish interaction relationships between droplets in the early stages of droplet growth.

[0058] (2) Droplet non-contact coupling migration mechanism;

[0059] Through capillary coupling caused by interfacial deformation of the lubricating layer, droplets can form mutual attraction within a certain distance, causing them to migrate directionally at the interface and gradually merge. Figure 3 As shown in the figure. This mechanism changes the limitation in traditional condensation interfaces that droplets must reach a relatively large size to move, allowing droplets to migrate at the microscale stage, thereby significantly reducing the residence time of droplets on the surface.

[0060] (3) Continuous water collection mechanism with self-updating interface;

[0061] By setting a droplet collection region 3 in the slip region 2, droplets preferentially gather in this region during migration and eventually exit the interface. Because the droplet collection region 3 of this invention has a micro-nano composite structure capable of forming a continuous water film and a specific width, after the continuous water film is formed, subsequent migrating droplets mainly engage in liquid-liquid contact with the existing water film, rather than directly engaging in strong pinning contact with the solid microstructure. Therefore, droplet retention in the droplet collection region 3 can be reduced, improving the continuity of droplet gathering and exit. Figure 5 As shown, since droplets can be continuously removed, new nucleation sites are constantly exposed on the surface, enabling continuous renewal of the surface of slip region 2 and facilitating the maintenance of a stable water collection process.

[0062] Through the above structural design, capillary coupling between droplets is formed on the lubricating layer, enabling droplets to migrate and merge in the early stage of formation. Under the synergistic effect of the interfacial driving force generated by capillary coupling and the capture effect of the droplet collection area 3, continuous transport and discharge are achieved, thus forming a continuous cycle of "droplet generation-migration-aggregation-discharge", that is, an amphiphilic sliding water collection process driven by capillary coupling of the lubricating interface, which significantly improves surface renewal efficiency and water collection performance.

[0063] The above-mentioned method for preparing amphiphilic sliding water-collecting surfaces driven by capillary coupling at the lubrication interface is as follows: Figure 4 As shown, the specific steps include:

[0064] Step 1) Substrate Pretreatment: The surface of substrate 1 is cleaned, polished, and made smooth and free of contaminants. Substrate 1 is a solid substrate with certain mechanical support and capable of supporting the slip layer and lubrication layer. The preferred material is any one of metal, glass, ceramic, silicon wafer, or polymer. The preferred metal material is aluminum, aluminum alloy, copper, stainless steel, titanium, or titanium alloy. In this embodiment, the droplet collection region 3 is constructed by electrodeposition; therefore, substrate 1 is preferably a conductive substrate, specifically an aluminum alloy sheet.

[0065] In other embodiments of the present invention, it is necessary to determine whether the substrate 1 is made of metal. If so, proceed directly to the next step. If not, a non-conductive substrate is used, and a conductive layer needs to be pre-formed on the surface of the non-conductive substrate. The conductive layer is prepared using existing processes such as chemical plating, magnetron sputtering, or gold spraying.

[0066] Step 2) Preparation of the slip layer: The prepolymer and curing agent are mixed at a mass ratio of 4~20:1 and subjected to a crosslinking reaction to obtain a polymer precursor. Then, the lubricant and polymer precursor are mixed uniformly at a mass ratio of 0.2~1:1 to obtain a lubricant mixture. The lubricant mixture is uniformly coated onto the surface of substrate 1, with a preferred coating thickness of 20 μm to maintain mechanical stability and thermal conductivity. The mixture is then uniformly heated at an environment not less than 60°C to cure it, forming the slip layer.

[0067] The prepolymer is used to prepare a polymer precursor that can be cured to form an elastomeric network, and is preferably one or a mixture of two or more of polydimethylsiloxane prepolymer, polyurethane prepolymer, fluorosilicone resin prepolymer, or acrylate prepolymer. The curing agent is a crosslinking agent capable of reacting with the prepolymer to form a crosslinked polymer network.

[0068] The lubricant is an oil-phase lubricant that can be adsorbed, stored and slowly released by a cross-linked polymer network, preferably one or a mixture of two or more of silicone oil, fluorosilicone oil, perfluoropolyether oil and mineral oil.

[0069] In this embodiment, the prepolymer is polydimethylsiloxane (PDMS) prepolymer, the lubricant is preferably silicone oil, and the curing agent is one of hydrogen-containing silicone oil crosslinking agents, platinum-catalyzed addition-type silicone rubber curing agents, or other commercially available polydimethylsiloxane-compatible curing agents.

[0070] The slip layer consists of a cross-linked polymer network and a lubricant dispersed therein. The cross-linked polymer network provides mechanical support, while the lubricant, stored within the network, migrates to the slip layer surface under capillary action, interfacial energy drive, or concentration gradient drive, thus forming a stable slip layer. This slip layer reduces the viscous force between the droplet and the solid substrate cross-linked polymer network and forms lubricating ridges at the droplet edges, providing an interfacial basis for capillary coupling migration between droplets.

[0071] The mass ratio of prepolymer to curing agent affects the crosslinking density and mechanical stability of the slip layer. When the proportion of curing agent is too high, the crosslinking density of the slip layer is too large, reducing the storage and release capacity of the lubricant in the elastomer network, which is not conducive to the formation of a stable slip layer. When the proportion of curing agent is too low, the slip layer is not fully cured, the mechanical stability decreases, and it is prone to deformation or detachment during subsequent processing or use. Therefore, the preferred mass ratio of prepolymer to curing agent is 4~20:1.

[0072] The mass ratio of lubricant to polymer precursor affects the lubricant storage capacity and surface slip layer stability. When the lubricant content is too low, it is difficult to form a continuous slip layer on the surface of slip region 2, and it is difficult to generate an effective lubricating ridge structure around the droplet. When the lubricant content is too high, the mechanical strength of the slip layer decreases, and the surface lubricant is prone to excessive precipitation and loss. Therefore, the preferred mass ratio of lubricant to polymer precursor is 0.2 to 1:1.

[0073] Step 3) Construction of droplet collection region 3:

[0074] The sample obtained in step 2) is placed in a femtosecond laser processing system, and laser ablation is performed on the sample according to the preset pattern in the droplet collection region 3 to remove the slip layer in the preset pattern region, such as... Figure 6 As shown in A. Subsequently, electrodeposition was performed on the ablated sample to form a metal micro / nano composite structure on a pre-defined pattern, serving as droplet collection region 3, as shown in... Figure 6 As shown in Figure B. The cathode in electrodeposition is the sample substrate 1, and the anode is metallic nickel or copper. The current density is 0.5~2 A / dm³. 2 The electrodeposition time is 0.1-2 h.

[0075] Electrodeposition is used to further construct metal micro / nano composite structures in the patterned region, enhancing the wetting differences, structural stability, and droplet aggregation ability of the droplet collection region 3. In other embodiments of the invention, such as using a non-conductive substrate, the cathode in the electrodeposition is a pre-formed conductive layer.

[0076] Current density and electrodeposition time together determine the deposition amount of the metal layer and the morphology of the micro / nano composite structure. Under the same conditions, a higher current density corresponds to a faster deposition rate, allowing for a shorter electrodeposition time. Conversely, a lower current density corresponds to a slower deposition rate, necessitating a longer electrodeposition time. By synergistically controlling the current density and electrodeposition time, a metal micro / nano composite structure with appropriate roughness and structural stability can be formed in the droplet collection region 3, thereby enhancing its ability to capture and aggregate droplets.

[0077] Step 4) Underwater competitive wetting treatment:

[0078] After cleaning, the sample obtained in step 3) is completely immersed in deionized water, allowing the droplet collection region 3 to be wetted by the aqueous phase first. Then, an oil-phase lubricant is slowly injected into the water-solid interface, preferentially covering the slip region 2. Because the droplet collection region 3 has high surface energy and a micro / nano composite structure after laser ablation and electrodeposition, it has a preferential retention capacity for the aqueous phase underwater. Meanwhile, the surrounding slip region 2 has a high affinity for the oil-phase lubricant; therefore, the oil-phase lubricant is mainly stably distributed in the slip region 2. After removing the sample from the deionized water and allowing it to stand for at least 6 hours, a stable lubricating layer forms on the surface of the slip region 2, and the droplet collection region 3 remains relatively hydrophilic or preferentially captures the aqueous phase, thus obtaining an amphiphilic slip-collecting water surface driven by capillary coupling at the lubrication interface.

[0079] The amount of oil-phase lubricant added is such that it completely covers the slip region 2 without completely submerging the droplet collection region 3. Preferably, the thickness of the lubricating layer is 2~20 μm, more preferably 2~5 μm. In this embodiment, the thickness of the lubricating layer on the surface of the slip region 2 after standing treatment is approximately 5 μm.

[0080] In this embodiment, PDMS prepolymer and curing agent are mixed at a mass ratio of 20:1 to obtain a polymer precursor. Silicone oil and the polymer precursor are then mixed at a mass ratio of 0.2:1, stirred until homogeneous, and coated onto the surface of substrate 1. The mixture is then cured at 60°C to obtain a slip layer. Subsequently, a femtosecond laser is used to ablate strip-shaped structures with a preset adjacent spacing of 0.5 mm, followed by electrodeposition, resulting in strip-shaped structures with a width of 360 μm, forming droplet collection region 3. After underwater competitive wetting treatment, an amphiphilic slip water-collecting surface driven by capillary coupling at the lubrication interface is obtained.

[0081] The water collection efficiency of the amphiphilic sliding water-collecting surface based on capillary coupling driven by the lubricating interface prepared in this embodiment was compared with that of a traditional wettable surface under different humidity levels. The results are as follows: Figure 7 As shown, it can be seen that the present invention effectively improves water collection efficiency through the synergistic effect of capillary coupling drive of lubricating ridge and directional capture of droplet collection region 3. Among them, the traditional wettable surface includes three types: sliding surface, superhydrophobic-superhydrophilic composite surface, and superhydrophobic surface.

[0082] Example 2

[0083] In this embodiment, substrate 1 is an aluminum alloy sheet. PDMS prepolymer and PDMS-compatible curing agent are mixed at a mass ratio of 10:1 to obtain a polymer precursor. Silicone oil and the polymer precursor are then mixed at a mass ratio of 0.2:1, stirred evenly, and coated onto the surface of substrate 1 with a coating thickness of 10 μm. The coating is then cured at 80°C to obtain a slip layer. Subsequently, a femtosecond laser is used to ablate strip-shaped structures with a preset adjacent spacing of 1 mm, followed by electrodeposition, resulting in strip-shaped structures with a width of 260 μm, forming droplet collection region 3. After underwater competitive wetting treatment, an amphiphilic slip water-collecting surface driven by capillary coupling at the lubrication interface is obtained, with a lubrication layer thickness of 5 μm.

[0084] Example 3

[0085] In this embodiment, substrate 1 is an aluminum alloy sheet. PDMS prepolymer and PDMS-compatible curing agent are mixed at a mass ratio of 4:1 to obtain a polymer precursor. Silicone oil and the polymer precursor are then mixed at a mass ratio of 1:1, stirred evenly, and coated onto the surface of aluminum alloy substrate 1 with a coating thickness of 15 μm. The coating is cured at 80°C to obtain a slip layer. Subsequently, a femtosecond laser is used to ablate strip-shaped structures with a preset adjacent spacing of 2 mm, followed by electrodeposition, resulting in a strip-shaped structure with a width of 310 μm, forming droplet collection region 3. After underwater competitive wetting treatment, an amphiphilic slip water-collecting surface driven by capillary coupling at the lubrication interface is obtained, with a lubrication layer thickness of 2 μm.

Claims

1. A double-slip water-collecting surface driven by capillary coupling at a lubricating interface, characterized in that: It includes a substrate and a sliding region and multiple droplet collection regions disposed on the surface of the substrate; The slip region includes a slip layer disposed on the substrate surface and a lubrication layer covering the surface of the slip layer; The slip layer includes a cross-linked polymer network and an oil-phase lubricant distributed in the cross-linked polymer network. The cross-linked polymer network can adsorb, store, and release the oil-phase lubricant. The lubrication layer is composed of an oil-phase lubricant. Multiple droplet collection areas are dispersed in the sliding area to facilitate the directional aggregation and discharge of droplets; the water contact angle of the droplet collection area is smaller than that of the sliding area.

2. The amphiphilic sliding water collection surface driven by capillary coupling at a lubrication interface according to claim 1, characterized in that: The water contact angle of the slip region is 95°~99°; The water contact angle of the droplet collection area is 0°~80°.

3. The amphiphilic sliding water collection surface driven by capillary coupling at a lubrication interface according to claim 2, characterized in that: The thickness of the lubricating layer is 2~20 μm; The droplet collection area is configured as a strip structure, and the surface is configured as a metal micro-nano composite structure; the width of the strip structure is 100~600 μm, and the spacing between adjacent strip structures is 0.5~2 mm.

4. The amphiphilic sliding water collection surface driven by capillary coupling at a lubrication interface according to claim 3, characterized in that: The thickness of the lubricating layer is 2~5 μm; The width of the strip-shaped structure is 260~400μm; The substrate is any one of metal, glass, ceramic, silicon wafer or polymer; The metal is one of aluminum, aluminum alloy, copper, stainless steel, titanium, or titanium alloy; The metal micro / nano composite structure is a nickel or copper metal micro / nano composite structure.

5. A method for preparing an amphiphilic sliding water-collecting surface based on capillary coupling driven by a lubricating interface as described in any one of claims 1-4, characterized in that: Step S0: Prepare the substrate according to the design requirements and pre-treat its surface; Then determine whether the substrate material is metal. If yes, proceed to step S1. If no, prepare a conductive layer on the substrate surface and then proceed to step S1. Step S1, preparation of slip layer: The prepolymer and curing agent are mixed and crosslinked to obtain a polymer precursor. Then, the oil phase lubricant is mixed evenly with the polymer precursor to obtain a lubricant mixture. The lubricant mixture is evenly coated on the substrate surface and heated evenly to cure it, forming a slip layer. Step S2, droplet collection area construction: According to the preset pattern of the droplet collection area, remove the slip layer of the corresponding area on the substrate surface, and process the droplet collection area on the substrate surface of the corresponding area; Step S3, underwater competitive wetting treatment: After cleaning the sample obtained in step S2, the droplet collection area is wetted with aqueous phase, and then a lubricating layer is prepared on the surface of the slip layer to obtain an amphiphilic slip water collection surface driven by capillary coupling of the lubrication interface.

6. The method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling at a lubrication interface according to claim 5, characterized in that: In step S1, the lubricant is one or a mixture of two or more of the following: silicone oil, fluorosilicone oil, perfluoropolyether oil, and mineral oil. The prepolymer is one or a mixture of two or more of polydimethylsiloxane prepolymer, polyurethane prepolymer, fluorosilicone resin prepolymer, or acrylate prepolymer; the curing agent is a crosslinking agent compatible with the prepolymer.

7. The method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling at a lubrication interface according to claim 6, characterized in that: In step S1, the coating thickness of the lubricant mixture is 10~20μm, and the heating temperature is 60~100℃; The mass ratio of the prepolymer to the curing agent is 4~20:1, and the mass ratio of the lubricant to the polymer precursor is 0.2~1:1; The prepolymer is a polydimethylsiloxane prepolymer, and the curing agent is one of a hydrogen-containing silicone oil crosslinking agent or a platinum-catalyzed addition-type silicone rubber curing agent.

8. The method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling at a lubrication interface according to claim 6, characterized in that, Step S2 is as follows: 2.1 Place the sample processed in step S1 into a femtosecond laser processing system, and perform laser ablation on the slip layer in the corresponding area of ​​the substrate surface according to the preset pattern of the droplet collection area to remove the slip layer in the corresponding area of ​​the substrate surface; 2.2 Electrodeposition is performed on the pre-designed pattern area of ​​the ablated sample to form a metal micro / nano composite structure, which serves as a droplet collection area; Step S3 is as follows: After cleaning the samples obtained in steps S3.1 and S2, they are completely immersed in deionized water so that the droplet collection area is wetted by the aqueous phase. Step S3.2: Then, oil-phase lubricant is slowly injected into the water-solid interface on the surface of the slip layer so that the oil-phase lubricant covers the slip region. The sample is taken out from the deionized water and then left to stand for at least 6 hours to form a lubricating layer on the surface of the slip region, thus obtaining an amphiphilic slip water collecting surface driven by capillary coupling of the lubricating interface.

9. The method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling at a lubrication interface according to claim 8, characterized in that: In step S1, the conductive layer is prepared by chemical plating, magnetron sputtering, or gold sputtering; In step S2, the cathode in the electrodeposition is the metal substrate of the sample or a pre-formed conductive layer, and the anode is nickel or copper. The current density for electrodeposition is 0.5~2 A / dm³. 2 The electrodeposition time is 0.1~2 h.

10. The method for preparing an amphiphilic sliding water-collecting surface driven by capillary coupling at a lubrication interface according to claim 9, characterized in that: In step S0, the pretreatment involves cleaning and polishing the substrate surface to make it smooth and free of contaminants. In step S1, the prepolymer is a polydimethylsiloxane prepolymer, the lubricant is silicone oil, the curing agent is a hydrogen-containing silicone oil crosslinking agent, and the coating thickness of the lubricant mixture is 20 μm.

Images