A super-hydrophobic coating with high mechanical stability and its preparation method and application

Abstract

The present application relates to a kind of repairable high mechanical stability super-hydrophobic coating and its preparation method and application, belong to coating material technical field.To the problem that super-hydrophobic coating is poor in mechanical stability, lacks self-repairing ability, the present application provides a kind of repairable high mechanical stability super-hydrophobic coating, main component includes epoxy resin, four acicular zinc oxide, nano alumina, nanometer silicon dioxide, micron carbon nanotube and micron aramid fiber.The present application is constructed by the micro-nano structure of bionic water strider leg, and has longitudinal gradient distribution three-dimensional surface micro-nano structure, can be repaired by sand paper polishing exposed bottom similar microstructure to realize performance.The network micro-nano structure of the coating in the present application is formed, has excellent mechanical stability and corrosion resistance.The coating spraying method of the present application supports large-area rapid construction, while compatible with a variety of substrate types, has wide application prospect in self-cleaning, anti-icing and other fields.

Description

Technical Field

[0001] This invention belongs to the field of coating materials technology, and in particular relates to a repairable superhydrophobic coating with high mechanical stability, its preparation method and application. Background Technology

[0002] Superhydrophobic coatings, with their extreme water repellency (contact angle >150°, roll-off angle <10°), show broad application prospects in self-cleaning, anti-icing, marine corrosion protection, and microfluidic control. Their core performance stems from the synergistic effect of micro / nano hierarchical structures and low surface energy materials. By constructing a Cassie-Baxter air cushion state, a stable air cushion is formed between the liquid and solid surface, significantly reducing the solid-liquid contact area and thus achieving a superhydrophobic effect. This structure not only endows the surface with excellent self-cleaning capabilities but also effectively inhibits icing, reduces fluid resistance, and resists the erosion of corrosive media in marine environments.

[0003] However, traditional superhydrophobic coatings face multiple challenges in practical engineering applications. First, the inherent mechanical fragility of micro / nano structures makes them highly susceptible to collapse under wear, scratching, or impact loads. For example, after being rubbed with sandpaper, the surface roughness of the coating decreases significantly, and the contact angle can drop by more than 30%, leading to a sharp decline in hydrophobic function. Second, the low surface energy materials used for surface modification are gradually depleted due to physical wear or chemical degradation, and lack self-repair capabilities, ultimately leading to irreversible functional loss. Summary of the Invention

[0004] To address the issues of poor mechanical stability and lack of self-repair capability in superhydrophobic coatings, this invention provides a repairable superhydrophobic coating with high mechanical stability, its preparation method, and its application.

[0005] The technical solution of the present invention:

[0006] A repairable superhydrophobic coating with high mechanical stability, comprising the following components in parts by weight:

[0007] The composition includes 10-15 parts epoxy resin, 40-50 parts anhydrous ethanol, 1-2 parts silane coupling agent, 2-4 parts tetraneedle zinc oxide, 4-8 parts perfluorodecyltriethoxysilane, 1-1.5 parts nano alumina, 2-4 parts nano silica, 0.5-1 part micron-sized carbon nanotubes, 0.5-1 part micron-sized aramid fiber, 20-30 parts ethyl acetate, 4-5 parts ammonia, and 1-2 parts curing agent.

[0008] Furthermore, the tetraneedle-shaped zinc oxide is a short needle type, with a single needle length of 3~25μm and a single needle diameter of 20~200nm.

[0009] Furthermore, the nano-alumina has a particle size of 20-40 nm; the nano-silica has a particle size of 20-60 nm; the micron-sized carbon nanotubes have a diameter of 10-100 nm and a length of 5-15 μm; and the micron-sized aramid fibers have a diameter of 5-20 μm and a length of 10-60 μm.

[0010] Furthermore, the epoxy resin is E51 type epoxy resin, the silane coupling agent is KH-560 silane coupling agent, and the curing agent is alicyclic amine 3388 curing agent.

[0011] A method for preparing a repairable superhydrophobic coating with high mechanical stability includes the following steps:

[0012] Step 1: Preparation of superhydrophobic particle dispersion:

[0013] Four needle-shaped zinc oxide, nano aluminum oxide, nano silica, micron-sized carbon nanotubes and micron-sized aramid fibers were dissolved in anhydrous ethanol, ultrasonically dispersed, and then silane coupling agent, ammonia and perfluorodecyltriethoxysilane were added. After stirring evenly, a superhydrophobic particle dispersion was obtained.

[0014] Step 2: Preparation of superhydrophobic aqueous solution:

[0015] The epoxy resin and ethyl acetate solution are mixed and stirred to obtain a uniformly dispersed epoxy resin solution; the superhydrophobic particle dispersion prepared in step one is added to the epoxy resin solution, ultrasonically dispersed and stirred for a certain time, then a curing agent is added, and after mixing and dispersing evenly, a superhydrophobic water solution is obtained.

[0016] Step 3: Preparation of superhydrophobic coating:

[0017] The superhydrophobic aqueous solution prepared in step two is sprayed onto the surface to be treated, and after curing, a superhydrophobic coating with repairable function is obtained.

[0018] Furthermore, the ultrasonic dispersion time in step one is 15-30 minutes, the stirring temperature is 60-70°C, and the stirring time is 5-7 hours.

[0019] Furthermore, in step two, the stirring temperature of the epoxy resin and ethyl acetate solution is 30~50℃, and the stirring time is 1~2h.

[0020] Furthermore, in step two, the ultrasonic dispersion time of the superhydrophobic particle dispersion and the epoxy resin solution is 10-20 min, and the stirring after ultrasonic dispersion is carried out at 20-25℃ for 30-40 min; after adding the curing agent, the mixture is stirred at 20-25℃ for 2-4 min, and then ultrasonically dispersed for 2-4 min.

[0021] Furthermore, the spraying thickness in step three is 10~70μm; the curing is carried out at 70℃ for 3 hours, or at room temperature for 7 days of natural curing.

[0022] Applications of a repairable superhydrophobic coating with high mechanical stability in the fields of self-cleaning, anti-icing, marine corrosion protection, or microfluidic control.

[0023] The beneficial effects of this invention are:

[0024] The superhydrophobic coating provided by this invention utilizes a biomimetic micro / nano structure inspired by the legs of water striders, employing tetra-needle-shaped zinc oxide particles as the coating framework to construct a three-dimensional surface micro / nano structure with a longitudinal gradient distribution. This unique "functional particle-resin-linear reinforcement" system endows the coating with superhydrophobic properties and repairability, resulting in a contact angle greater than 150°. When the coating surface fails due to wear caused by external forces, the underlying similar micro / nano structure can be exposed by sanding, restoring the hydrophobic properties to above 150°, thus achieving repairability. Furthermore, the brittle properties of the epoxy resin synergistically interact with the longitudinal structural similarity of the coating's internal system, further optimizing the controllability of the repair process.

[0025] This invention utilizes the interaction of needle-like zinc oxide, functional particles, and epoxy resin to form a robust and stable network micro / nano structure. The three-dimensional structure of this coating ensures both robust and stable superhydrophobic properties and excellent mechanical stability. Simultaneously, the chemical stability of the epoxy resin and the chemical inertness of the alumina and carbon nanotubes contribute to the coating's excellent corrosion resistance. Using epoxy resin as the matrix material ensures strong adhesion between the coating and the substrate, avoiding the adhesion degradation caused by filler additions. This design allows the coating to maintain structural integrity during long-term service, making it suitable for harsh environments such as those in ships and wind turbine blades.

[0026] This invention employs a one-step spraying process, using high temperature or natural curing to allow solvent evaporation and create pores, forming a mechanically stable three-phase composite structure. The coating spraying method of this invention supports large-area, rapid application and is compatible with various substrate types. It has broad application prospects in self-cleaning, anti-icing, marine corrosion protection, and microfluidic control fields. Attached Figure Description

[0027] Figure 1 The water contact angle diagram of the superhydrophobic coating prepared in Example 1;

[0028] Figure 2 The image shows the water contact angle of the superhydrophobic coating prepared in Example 2.

[0029] Figure 3 The water contact angle diagram of the superhydrophobic coating prepared in Example 3;

[0030] Figure 4 The image shows a comparison of the water contact angle and roll-off angle of the superhydrophobic coating prepared in Example 1 after different wear cycles in a sandpaper abrasion test.

[0031] Figure 5 The figures show the water contact angle of the failed surface of the superhydrophobic coating prepared in Example 1 and the water contact angle and roll-off angle of the sandpaper-repaired surface.

[0032] Figure 6 The figures show the water contact angle of the failed surface of the superhydrophobic coating prepared in Example 2 and the water contact angle and roll-off angle of the sandpaper-repaired surface.

[0033] Figure 7 The figures show the water contact angle of the failed surface of the superhydrophobic coating prepared in Example 3 and the water contact angle and roll-off angle of the sandpaper-repaired surface.

[0034] Figure 8 SEM images of the initial and failed surfaces of the superhydrophobic coating prepared in Example 1, where a is the initial surface and b is the failed surface;

[0035] Figure 9 The images are SEM micrographs of the surfaces repaired by sandpaper in Examples 1, 2, and 3. a is Example 1, b is Example 2, and c is Example 3. Detailed Implementation

[0036] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0037] Example 1

[0038] This embodiment provides a repairable superhydrophobic coating with high mechanical stability and its preparation method.

[0039] This embodiment of the repairable superhydrophobic coating with high mechanical stability consists of the following components in parts by weight:

[0040] 15 parts of E51 epoxy resin, 40 parts of anhydrous ethanol, 1 part of silane coupling agent KH-560, 2 parts of tetraneedle zinc oxide, 4 parts of perfluorodecyltriethoxysilane, 1.5 parts of nano alumina, 4 parts of nano silica, 0.5 parts of micron-sized carbon nanotubes, 1 part of micron-sized aramid fiber, 30 parts of ethyl acetate, 4 parts of ammonia, and 2 parts of cycloaliphatic amine 3388 curing agent.

[0041] In this embodiment, the four needle-like zinc oxides are short needles, with a single needle length of 3~25μm and a single needle diameter of 20~200nm; the nano-alumina has a particle size of 20~40nm; the nano-silica has a particle size of 20~60nm; the micron-sized carbon nanotubes have a diameter of 10~100nm and a length of 5~15μm; and the micron-sized aramid fibers have a diameter of 5~20μm and a length of 10~60μm.

[0042] The method for preparing a highly mechanically stable superhydrophobic coating in this embodiment includes the following steps:

[0043] Step 1: Preparation of superhydrophobic particle dispersion:

[0044] Four needle-shaped zinc oxide, nano-alumina, nano-silica, micron-sized carbon nanotubes and micron-sized aramid fibers were dissolved in anhydrous ethanol, ultrasonically dispersed for 20 min, and then silane coupling agent, ammonia and perfluorodecyltriethoxysilane were added. The mixture was magnetically stirred at 60 °C for 6 h to obtain a superhydrophobic particle dispersion.

[0045] Step 2: Preparation of superhydrophobic aqueous solution:

[0046] Epoxy resin and ethyl acetate solution were mixed and magnetically stirred at 30°C for 1 hour to obtain a uniformly dispersed epoxy resin solution. The superhydrophobic particle dispersion prepared in step one was added to the obtained epoxy resin solution, and the mixture was ultrasonically dispersed for 10 minutes. Stir magnetically for 30 minutes, add cycloaliphatic amine 3388 curing agent, stir magnetically for 3 minutes at 25°C, and ultrasonically disperse for 3 minutes. After mixing and dispersing evenly, a superhydrophobic solution is obtained.

[0047] Step 3: Preparation of superhydrophobic coating:

[0048] The superhydrophobic solution prepared in step two was poured into a spray gun and sprayed onto the substrate surface under a pressure of less than 1 MPa. The solution was then cured in a 70°C oven for 3 hours to obtain a 60 μm thick superhydrophobic coating with repairable function.

[0049] Example 2

[0050] This embodiment provides a repairable superhydrophobic coating with high mechanical stability and its preparation method.

[0051] This embodiment of the repairable superhydrophobic coating with high mechanical stability consists of the following components in parts by weight:

[0052] 10 parts E51 epoxy resin, 45 parts anhydrous ethanol, 1 part silane coupling agent KH-560, 4 parts tetraneedle zinc oxide, 4 parts perfluorodecyltriethoxysilane, 1.5 parts nano alumina, 2 parts nano silica, 0.5 parts micron-sized carbon nanotubes, 1 part micron-sized aramid fiber, 30 parts ethyl acetate, 4 parts ammonia, and 2 parts cycloaliphatic amine 3388 curing agent.

[0053] In this embodiment, the four needle-like zinc oxides are short needles, with a single needle length of 3~25μm and a single needle diameter of 20~200nm; the nano-alumina has a particle size of 20~40nm; the nano-silica has a particle size of 20~60nm; the micron-sized carbon nanotubes have a diameter of 10~100nm and a length of 5~15μm; and the micron-sized aramid fibers have a diameter of 5~25μm and a length of 10~60μm.

[0054] The method for preparing a highly mechanically stable superhydrophobic coating in this embodiment includes the following steps:

[0055] Step 1: Preparation of superhydrophobic particle dispersion:

[0056] Four needle-shaped zinc oxide, nano-alumina, nano-silica, micron-sized carbon nanotubes and micron-sized aramid fibers were dissolved in anhydrous ethanol, ultrasonically dispersed for 20 min, and then silane coupling agent, ammonia and perfluorodecyltriethoxysilane were added. The mixture was magnetically stirred at 60 °C for 6 h to obtain a superhydrophobic particle dispersion.

[0057] Step 2: Preparation of superhydrophobic aqueous solution:

[0058] Epoxy resin and ethyl acetate solution were mixed and magnetically stirred at 30°C for 1 hour to obtain a uniformly dispersed epoxy resin solution. The superhydrophobic particle dispersion prepared in step one was added to the obtained epoxy resin solution, and the mixture was ultrasonically dispersed for 10 minutes. Stir magnetically for 30 minutes, add cycloaliphatic amine 3388 curing agent, stir magnetically for 3 minutes at 25°C, and ultrasonically disperse for 3 minutes. After mixing and dispersing evenly, a superhydrophobic solution is obtained.

[0059] Step 3: Preparation of superhydrophobic coating:

[0060] The superhydrophobic solution prepared in step two was poured into a spray gun and sprayed onto the substrate surface under a pressure of less than 1 MPa. The solution was then cured in a 70°C oven for 3 hours to obtain a 60 μm thick superhydrophobic coating with repairable function.

[0061] Example 3

[0062] This embodiment provides a repairable superhydrophobic coating with high mechanical stability and its preparation method.

[0063] This embodiment of the repairable superhydrophobic coating with high mechanical stability consists of the following components in parts by weight:

[0064] 15 parts of E51 epoxy resin, 45 parts of anhydrous ethanol, 1 part of silane coupling agent KH-560, 3 parts of tetraneedle zinc oxide, 4 parts of perfluorodecyltriethoxysilane, 2 parts of nano alumina, 3 parts of nano silica, 0.5 parts of micron-sized carbon nanotubes, 1 part of micron-sized aramid fiber, 30 parts of ethyl acetate, 4 parts of ammonia, and 2 parts of alicyclic amine 3388 curing agent.

[0065] In this embodiment, the four needle-like zinc oxides are short needles, with a single needle length of 3~25μm and a single needle diameter of 20~200nm; the nano-alumina has a particle size of 20~40nm; the nano-silica has a particle size of 20~60nm; the micron-sized carbon nanotubes have a diameter of 10~100nm and a length of 5~15μm; and the micron-sized aramid fibers have a diameter of 5~20μm and a length of 10~60μm.

[0066] The method for preparing a highly mechanically stable superhydrophobic coating in this embodiment includes the following steps:

[0067] Step 1: Preparation of superhydrophobic particle dispersion:

[0068] Four needle-shaped zinc oxide, nano-alumina, nano-silica, micron-sized carbon nanotubes and micron-sized aramid fibers were dissolved in anhydrous ethanol, ultrasonically dispersed for 20 min, and then silane coupling agent, ammonia and perfluorodecyltriethoxysilane were added. The mixture was magnetically stirred at 60 °C for 6 h to obtain a superhydrophobic particle dispersion.

[0069] Step 2: Preparation of superhydrophobic aqueous solution:

[0070] Epoxy resin and ethyl acetate solution were mixed and magnetically stirred at 30°C for 1 hour to obtain a uniformly dispersed epoxy resin solution. The superhydrophobic particle dispersion prepared in step one was added to the obtained epoxy resin solution, and the mixture was ultrasonically dispersed for 10 minutes. Stir magnetically for 30 minutes, add cycloaliphatic amine 3388 curing agent, stir magnetically for 3 minutes at 25°C, and ultrasonically disperse for 3 minutes. After mixing and dispersing evenly, a superhydrophobic solution is obtained.

[0071] Step 3: Preparation of superhydrophobic coating:

[0072] The superhydrophobic solution prepared in step two was poured into a spray gun and sprayed onto the substrate surface under a pressure of less than 1 MPa. The solution was then dried and cured at room temperature for 7 days to obtain a 60 μm thick superhydrophobic coating with repairable function.

[0073] I. The water contact angles of the coatings obtained in Examples 1, 2, and 3 were examined, and the results are as follows: Figure 1 , Figure 2 and Figure 3 As shown, the water contact angle of the coating prepared in Example 1 is 162.8°, the water contact angle of the coating prepared in Example 2 is 160.6°, and the water contact angle of the coating prepared in Example 3 is 163.9°. The water contact angle data from Examples 1 to 3 demonstrate that the superhydrophobic coatings prepared in this invention all possess excellent hydrophobic properties. Water droplets on the coating surface are nearly spherical and can roll off with slight tilting, simultaneously carrying away dust and contaminants, thus achieving self-cleaning.

[0074] 2. Place a 100 g weight on a stainless steel plate with a superhydrophobic coating on 600 grit sandpaper, and conduct a sandpaper abrasion test under a pressure of 100 g. Move the sample forward 10 cm and then pull it back, with a friction distance of 20 cm as one cycle. Measure the water contact angle and roll-off angle after every 10 cycles to test the mechanical stability of the coating.

[0075] Figure 4 The results of the abrasion test on the coated sandpaper prepared in Example 1 are as follows: Figure 4 As shown, within a coating thickness range of 60 μm, after 260 wear cycles, the water contact angle of the coating can still maintain [value missing]. Above, the roll angle is less than The results show that its superhydrophobic properties and self-cleaning function remain significant even after mechanical wear, indicating that the coating surface microstructure has strong resistance to damage and can withstand 260 sandpaper abrasion cycles. Under the same test conditions, the coatings in Examples 2 and 3 can withstand 160 and 220 sandpaper abrasion cycles, respectively, further verifying the excellent mechanical stability of this coating system and providing reliable assurance for long-term application in harsh environments.

[0076] 3. Apply a pressure greater than 200 N in the longitudinal direction to the coating prepared in Example 1 and maintain it for more than 1 minute to destroy the micro-nano structure of the superhydrophobic coating surface and reduce its water contact angle to [value missing]. Subsequently, the failed surface was sanded approximately 10 times with 600-grit sandpaper. The water contact angle (WCA) and roll-off angle (WSA) of the coating were then tested, and the results are as follows: Figure 5 As shown, the water contact angle of the coating returned to normal after repair. The roll angle is .

[0077] The coatings prepared in Examples 2 and 3 were tested using the same test method, and the results are as follows: Figure 6 and Figure 7 As shown, the water contact angle of the coating in Example 2 was reduced to 145.6°. After sanding and repair, the water contact angle was restored to [value missing]. The roll-off angle was 4.2°; the water contact angle of the coating in Example 3 was reduced to 141.5°, and after sanding and repair, the water contact angle was restored to 159.7° and the roll-off angle was 8.7°.

[0078] The initial morphology and failure morphology of the coating in Example 1 were analyzed by SEM, and the results are as follows: Figure 8 As shown, it can be observed that under external impact pressure, the surface micro-nano structure of the coating is flattened, the coating roughness decreases, and the water contact angle decreases.

[0079] The surface microstructure of the coatings in Examples 1, 2, and 3 after sandpaper abrasion repair was characterized by SEM. The results are as follows: Figure 9 As shown, after sanding and repair, the coating's micro-nano structure is reconstructed, its roughness increases, and its superhydrophobicity is restored.

[0080] The recovery of the water contact angle and the microstructure of the coating surface indicates that the superhydrophobic coating prepared in this invention possesses repairable functionality. This invention utilizes a biomimetic micro / nano structure inspired by the legs of a water strider, employing a linear reinforcement as the coating framework to construct a three-dimensional surface micro / nano structure with a longitudinal gradient distribution. When the coating surface fails due to wear caused by external forces, the underlying similar micro / nano structure can be exposed by sanding, restoring the hydrophobic properties to over 150°, thus achieving repairability. This repair method is simple to operate, requiring no complex equipment or harsh conditions, significantly improving the coating's lifespan and practicality, and has significant value in practical applications.

Claims

1. A repairable superhydrophobic coating with high mechanical stability, characterized in that, It consists of the following components in parts by weight: The composition includes 10-15 parts epoxy resin, 40-50 parts anhydrous ethanol, 1-2 parts silane coupling agent, 2-4 parts tetraneedle zinc oxide, 4-8 parts perfluorodecyltriethoxysilane, 1-1.5 parts nano-alumina, 2-4 parts nano-silica, 0.5-1 part micron-sized carbon nanotubes, 0.5-1 part micron-sized aramid fiber, 20-30 parts ethyl acetate, 4-5 parts ammonia, and 1-2 parts curing agent. The tetraneedle zinc oxide is short needle-shaped. The structure has a single needle length of 3~25μm and a single needle diameter of 20~200nm; the nano-alumina has a particle size of 20~40nm; the nano-silica has a particle size of 20~60nm; the micron-sized carbon nanotubes have a diameter of 10~100nm and a length of 5~15μm; the micron-sized aramid fibers have a diameter of 5~20μm and a length of 10~60μm; and the silane coupling agent is KH-560 silane coupling agent. The method for preparing the repairable, highly mechanically stable superhydrophobic coating includes the following steps: Step 1: Preparation of superhydrophobic particle dispersion: Four needle-shaped zinc oxide, nano aluminum oxide, nano silica, micron-sized carbon nanotubes and micron-sized aramid fibers were dissolved in anhydrous ethanol, ultrasonically dispersed, and then silane coupling agent, ammonia and perfluorodecyltriethoxysilane were added. After stirring evenly, a superhydrophobic particle dispersion was obtained. Step 2: Preparation of superhydrophobic aqueous solution: Epoxy resin and ethyl acetate were mixed and stirred to obtain a uniformly dispersed epoxy resin solution; the superhydrophobic particle dispersion prepared in step one was added to the epoxy resin solution, ultrasonically dispersed and stirred for a certain time, then a curing agent was added, and after mixing and dispersing evenly, a superhydrophobic water solution was obtained. Step 3: Preparation of superhydrophobic coating: The superhydrophobic aqueous solution prepared in step two is sprayed onto the surface to be treated, and after curing, a superhydrophobic coating with repairable function is obtained.

2. The superhydrophobic coating with high repairability and mechanical stability according to claim 1, characterized in that, The epoxy resin is E51 type epoxy resin, and the curing agent is alicyclic amine 3388 curing agent.

3. The superhydrophobic coating with high repairability and mechanical stability according to claim 1, characterized in that, The ultrasonic dispersion time in step one is 15~30 min, the stirring temperature is 60~70℃, and the stirring time is 5~7 h.

4. The superhydrophobic coating with high repairability and mechanical stability according to claim 3, characterized in that, In step two, the stirring temperature of the epoxy resin and ethyl acetate is 30~50℃, and the stirring time is 1~2h.

5. The superhydrophobic coating with high repairability and mechanical stability according to claim 4, characterized in that, The ultrasonic dispersion time of the superhydrophobic particle dispersion and epoxy resin solution in step two is 10-20 min. After ultrasonic dispersion, the stirring is carried out at 20-25℃ for 30-40 min. After adding the curing agent, the mixture is stirred at 20-25℃ for 2-4 min and then ultrasonically dispersed for 2-4 min.

6. The superhydrophobic coating with repairable high mechanical stability according to claim 5, characterized in that, Step 3: The coating thickness is 10~70μm; the curing is carried out at 70℃ for 3 hours, or at room temperature for 7 days of natural curing.

7. The application of a repairable, highly mechanically stable superhydrophobic coating as described in claim 1 or 2 in the fields of self-cleaning, anti-icing, marine corrosion protection, or microfluidic control.

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