Photoelectric-thermal super-hydrophobic composite film and preparation method and application thereof

Abstract

The invention belongs to the technical field of anti-icing / deicing, and particularly relates to a photoelectric thermal super-hydrophobic composite film and a preparation method and application thereof. The composite film comprises a first polydimethylsiloxane substrate and an electric heating bottom layer attached to the first polydimethylsiloxane substrate, a photo-thermal super-hydrophobic coating is attached to the electric heating bottom layer, and the photo-thermal super-hydrophobic coating is a mixed coating formed by depositing silicon dioxide and cobalt on the surface of a second polydimethylsiloxane substrate. According to the combination of the photo-thermal characteristic and the super-hydrophobic characteristic of the composite film, the ice preventing and removing performance of the super-hydrophobic surface is further enhanced, and an aircraft ice control system is built based on the composite film. The photoelectric-thermal super-hydrophobic composite film is formed, the surface of the coating is of a micro-nano-scale coarse structure, the coating has super-hydrophobicity, passive anti-icing can be achieved, the photo-thermal characteristic and the super-hydrophobic characteristic are combined, icing detection and active and passive anti-icing are combined, anti-icing and anti-icing are more efficient, energy consumption is reduced, and anti-icing and anti-icing stability is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-icing / de-icing, and in particular relates to a photoelectric thermal super-hydrophobic composite film and a preparation method and application thereof. Background Art

[0002] Icing is one of the biggest potential threats to aircraft flight. When an aircraft flies in the atmosphere, the presence of supercooled water droplets and ice crystals in the atmosphere can easily cause ice to form on the aircraft's wings. Ice on the aircraft's wing surface will change the pressure distribution on the aircraft's surface, thereby reducing the lift-to-drag ratio, causing the aircraft to flutter, and affecting the aircraft's maneuverability. Therefore, it is necessary to conduct real-time and accurate ice detection and de-icing on the icing-prone part of the wing's leading edge.

[0003] At present, there are seven methods for ice detection applied to aircraft, namely intuitive method, resonance method, optical method, electrical method, thermal method, waveguide method and hybrid method. The microwave resonant sensor developed by Golovin and Zarifi et al. detects ice conditions by observing transient changes in parameters such as resonant frequency and resonant amplitude. Zhi et al. used capacitive sensors to study the process of surface ice formation under different relative humidity. Zhang et al. used optical fiber sensors to monitor the reflected light, scattered light and diffuse light of ice in real time to detect the surface ice thickness and ice growth rate, and accurately identify different types of ice. The above scholars conducted research on surface ice conditions and did not add anti-icing technology to solve the ice problem.

[0004] At the same time, in order to avoid the loss of aircraft performance caused by icing, engineers and technicians have developed a variety of anti-icing methods, including traditional active anti-icing technology and bionic anti-icing coating technology. Qin et al. developed a thin film based on MXene / CNT that combines hydrophobicity, dual-driven heating and sensitivity. Superhydrophobic coatings can achieve passive anti-icing. Due to the excellent water repellency of the surface, it does not need to consume external energy. However, superhydrophobic coatings often melt after multiple freezing. The mechanical interlocking of ice in the rough structure increases adhesion, and extremely small droplets are pinned in the surface microstructure, destroying the surface hydrophobicity. And once it loses light, the melted water droplets will freeze again. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a photoelectric thermal super-hydrophobic composite film and its preparation method and application. An aircraft ice control system is built based on the multi-layer functional composite film. The system detects the icing environment in real time, detects the icing state, ambient temperature and humidity, and automatically controls electric heating to prevent deicing. This makes deicing more efficient, reduces energy consumption, and improves the stability of deicing.

[0006] The present invention solves the above technical problems through the following technical solutions.

[0007] The first object of the present invention is to provide a photo-thermal super-hydrophobic composite film, which includes a first polydimethylsiloxane substrate and an electrothermal bottom layer attached to the first polydimethylsiloxane substrate, and a photo-thermal super-hydrophobic coating is attached to the electrothermal bottom layer, wherein the photo-thermal super-hydrophobic coating is a mixed coating formed by depositing silicon dioxide and cobalt on the surface of the second polydimethylsiloxane substrate, and the second polydimethylsiloxane substrate is attached to the electrothermal bottom layer.

[0008] Furthermore, the thickness of the first polydimethylsiloxane base is 0.3 mm to 0.5 mm, the thickness of the electrothermal base layer is 0.04 mm to 0.06 mm, and the thickness of the photothermal superhydrophobic coating is 0.4 mm to 0.6 mm.

[0009] Furthermore, the electric heating material used in the electric heating bottom layer is carbon nanotubes, graphene or MXene material.

[0010] A second object of the present invention is to provide a method for preparing the above-mentioned photoelectric thermal super-hydrophobic composite film, comprising the following steps:

[0011] The first polydimethylsiloxane solution is coated on the aluminum alloy substrate, and pre-cured for the first time to obtain the first polydimethylsiloxane base.

[0012] The electric heating bottom layer is bonded to the first polydimethylsiloxane base to obtain the carbon nanotube electric heating bottom layer attached to the polydimethylsiloxane base.

[0013] A second polydimethylsiloxane solution is coated on the electrothermal base layer, and pre-cured for a second time to form a second polydimethylsiloxane base. Then, a silicon dioxide / cobalt mixed solution is evenly sprayed on the second polydimethylsiloxane base and cured to obtain a photothermal super-hydrophobic coating.

[0014] After stripping the aluminum alloy substrate, the photoelectric thermal super-hydrophobic composite film is prepared.

[0015] Furthermore, the silica / cobalt mixed solution is formed by mixing silica, cobalt and a dispersant in a mass ratio of 1:7.5 to 8.5:1, and the dispersant is anhydrous ethanol.

[0016] Furthermore, the silicon dioxide / cobalt mixed solution is sprayed on the second polydimethylsiloxane substrate at an angle of 45 degrees, and the curing temperature is 90° C. to 120° C. and the curing time is 8 min to 12 min.

[0017] Furthermore, the first polydimethylsiloxane solution and the second polydimethylsiloxane solution are both formed by mixing polydimethylsiloxane and a curing agent in a mass ratio of 9.5 to 10.5:1, the temperatures of the first pre-curing and the second pre-curing are both 60° C. to 80° C., and the curing time is both 8 min to 12 min.

[0018] The third object of the present invention is to provide the application of the above-mentioned photoelectric thermal super-hydrophobic composite film in an aircraft anti-icing control system.

[0019] Furthermore, the aircraft anti-icing control system includes: a capacitive sensing electrode, a temperature sensing electrode and a humidity sensing electrode are embedded in the photothermal super-hydrophobic coating of the photothermal super-hydrophobic composite film.

[0020] The anti-icing controller is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film. The anti-icing controller includes an anti-icing controller single chip, an icing sensor module, a temperature sensor module, a humidity sensor module, an electric heating deicing module, a data acquisition control circuit and an external server.

[0021] The electrical signal of the capacitive sensing electrode is connected to the ice sensing module, the electrical signal of the temperature sensing electrode is connected to the temperature sensing module, and the electrical signal of the humidity sensing electrode is connected to the humidity sensing module.

[0022] The icing sensor module, the temperature sensor module and the humidity sensor module are all electrically connected to the anti-icing controller microcontroller, and the anti-icing controller microcontroller is connected to the external server through the data acquisition connection line signal, which is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film and transmit it to the external server. The external server signal is connected to the electric thermal deicing module, and the electric thermal deicing module signal is connected to the photothermal super-hydrophobic coating to heat the photoelectric thermal super-hydrophobic composite film to prevent deicing.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention is attached with a photothermal super-hydrophobic coating on the electric heating bottom, forming a photothermal super-hydrophobic composite film, in an unfrozen environment, the photothermal super-hydrophobic coating on the film surface is used to prevent ice, and the super-hydrophobic coating can realize passive anti-icing, due to the excellent water repellency of the surface, it is not necessary to consume external energy, but the super-hydrophobic coating often destroys the surface hydrophobicity due to ice melting after repeated freezing, so adding photothermal performance can quickly increase the temperature of the surface coating to evaporate the water in the super-hydrophobic coating, and photothermal and hydrophobic properties can effectively alleviate the freezing time. Wherein, the photothermal super-hydrophobic coating is evenly sprayed on the polydimethylsiloxane base with silicon dioxide and cobalt dispersion solution, and the Co particles modified by SiO2 are deposited on the polydimethylsiloxane base surface, so that the coating surface presents a rough structure of micro-nano level, and the droplet presents a high contact angle on the coating surface, with super-hydrophobicity, can slide down under its own gravity or slight external force, so as to effectively prevent the occurrence of freezing behavior, embodying excellent super-hydrophobicity, enhancing the absorption and storage capacity of light.

[0025] (2) The present invention provides a multilayer composite film with ice detection, super-hydrophobic passive anti-icing, and electrothermal / photothermal active anti-icing and deicing functions. The photothermal property is combined with the super-hydrophobic property to further enhance the anti-icing performance of the photothermal super-hydrophobic surface. An aircraft ice control system is built based on the multilayer functional film. When the ice detector detects the freezing point, the heating module is automatically turned on to energize the carbon nanotube film for heating. The system detects the freezing environment in real time, detects the freezing state, ambient temperature and humidity, and automatically controls the electric heating for anti-icing. The anti-icing is made more efficient, energy consumption is reduced, and the stability of the anti-icing is improved. The entire composite film is a plane and is flexible. It can be installed on any part of the aircraft without changing the aerodynamic shape of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a process flow chart for the preparation of photoelectric thermal super-hydrophobic composite films.

[0027] Figure 2 This is a system process diagram of the aircraft anti-icing and de-icing control system of the present invention.

[0028] Figure 3 The surface morphology of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention and Comparative Example 1 is shown in FIG. Figure 3 a to d in the figure are the microstructures of PCo-PCNT at scales of 100μm, 50μm, 10μm and 1μm, respectively, and e to h are the microstructures of PCoSi-PCNT at scales of 100μm, 50μm, 10μm and 1μm, respectively.

[0029] Figure 4 This is the elemental EDS layering diagram of the photoelectric thermal super-hydrophobic composite film of comparative example 1 of the present invention.

[0030] Figure 5 This is the elemental EDS layering diagram of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention.

[0031] Figure 6 The hydrophobicity diagram of the PDMS of the present invention, Example 1 and Comparative Example 1 is shown.

[0032] Figure 7 This is a diagram of the silver mirror phenomenon of the photoelectric thermal super-hydrophobic composite film of the present invention's PDMS, Example 1 and Comparative Example 1.

[0033] Figure 8 Infrared imaging of the surface temperature rise of the photoelectric thermal super-hydrophobic composite film of the PDMS of the present invention, Example 1 and Comparative Example 1.

[0034] Fig. 9 The surface temperature rise and cooling curves of the PDMS, Example 1 and Comparative Example 1 photoelectric thermal super-hydrophobic composite films of the present invention are shown.

[0035] Fig.10 This is a curve showing the change of the ice capacitance value of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention over time under different relative humidity environments, wherein: Fig.10 In a, the change curve graph is from 0s to 700s, the small graph displayed in the lower left corner of a is the interval change curve graph from 0s to 50s, b is the interval change curve graph from 30s to 100s, and c is the interval change curve graph from 330s to 470s.

[0036] Fig.11 The surface temperature rise curves of the deicing control electric heating system under different voltages are shown below: Fig.11 a is the temperature rise curve of the surface at 3.3V and 5V, b is the temperature rise curve of the surface when the icing condition is reached and the output voltage is 3V, and c is the curve when the surface temperature is controlled in the range of 42℃~55℃.

[0037] Fig.12 This is a test diagram of the anti-icing performance of the photoelectric thermal super-hydrophobic composite film of the present invention PDMS, Example 1 and Comparative Example 1, wherein: Fig.12 a is a diagram showing the freezing process of water droplets on PDMS, PCo-PCNT and PCoSi-PCNT, b is a diagram showing the electric heating anti-icing in Example 1, and c is the electric heating performance when the water droplets in Example 1 are completely frozen. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be purchased from the market or prepared by existing methods.

[0040] Existing technologies such as Qin et al. have developed a thin film based on MXene / CNT that combines hydrophobicity, dual-driven heating and sensitivity. Superhydrophobic coatings can achieve passive anti-icing. Due to the excellent water repellency of the surface, it does not need to consume external energy. However, superhydrophobic coatings often thaw after multiple freezing. The mechanical interlocking of ice in the rough structure increases adhesion, and extremely small droplets are pinned in the surface microstructure, destroying the surface hydrophobicity. Moreover, once it loses light, the melted water droplets will freeze again.

[0041] Based on the above problems, the present invention provides a multilayer composite film with ice detection, super-hydrophobic passive anti-icing, and electrothermal / photothermal active anti-icing and de-icing functions. The photothermal property is combined with the super-hydrophobic property to further enhance the anti-icing and de-icing performance of the super-hydrophobic surface, and an aircraft ice control system is built based on the multilayer functional film. The system detects the icing environment in real time, detects the icing state, ambient temperature and humidity, and automatically controls the electric heating anti-icing, making the anti-icing more efficient, reducing energy consumption, and improving the stability of the anti-icing.

[0042] On the one hand, the present invention provides a photo-thermal super-hydrophobic composite film, which includes a first polydimethylsiloxane substrate and an electrothermal bottom layer attached to the first polydimethylsiloxane substrate, and a photo-thermal super-hydrophobic coating is attached to the electrothermal bottom layer, wherein the photo-thermal super-hydrophobic coating is a mixed coating formed by depositing silicon dioxide and cobalt on the surface of the second polydimethylsiloxane substrate, and the second polydimethylsiloxane substrate is attached to the electrothermal bottom layer.

[0043] The present invention is attached with a photothermal super-hydrophobic coating on the electric heating bottom layer to form a photothermal super-hydrophobic composite film. In an unfrozen environment, the photothermal super-hydrophobic coating on the film surface is used to prevent ice. The super-hydrophobic water coating can achieve passive anti-icing, and due to the excellent water repellency of the surface, it is not necessary to consume external energy, but the super-hydrophobic coating often destroys the surface hydrophobicity due to repeated thawing after freezing. Therefore, adding photothermal performance can quickly increase the temperature of the surface coating to evaporate the water in the super-hydrophobic coating, and photothermal and hydrophobic properties can effectively alleviate the freezing time. When the ice detector detects the freezing point, the heating module is automatically turned on to make the electric heating bottom layer energized and heated. In the composite film, the electric heating bottom layer can also be used as deicing as anti-icing. The whole composite film is a plane, and is flexible, can be installed in any part of the aircraft, and does not change the aerodynamic shape of the aircraft.

[0044] In some specific embodiments, the thickness of the first polydimethylsiloxane base is 0.3mm~0.5mm, the thickness of the electrothermal bottom layer is 0.04mm~0.06mm, and the thickness of the photothermal super hydrophobic coating is 0.4mm~0.6mm. Among them, the thickness change of the first polydimethylsiloxane base has almost no effect on the performance of the photothermal super hydrophobic composite film; the thickness of the electrothermal bottom layer will affect its electrical conductivity, and thicker films usually have better electrical conductivity, because when the thickness increases, the conductive paths between the electrothermal bottom layers increase, and electrons can flow more easily, however, overly thick films may cause defects in the conductive path to increase, thereby reducing conductivity. Therefore, the thickness of the electrothermal bottom layer is selected to be 0.04mm~0.06mm; photothermal super hydrophobic coating, as the thickness increases, the mechanical strength of the coating will increase, but being too thick will affect toughness, so the thickness of the photothermal super hydrophobic coating is selected to be 0.4mm~0.6mm.

[0045] In some specific embodiments, the electric heating material used in the electric heating bottom layer is carbon nanotubes, graphene or MXene materials. Compared with the metal copper foil commonly used in traditional aircraft electric heating, the conductivity of the carbon nanotube film is lower than that of pure copper foil, resulting in a higher resistivity. In addition, preferably, the electric heating material used in the electric heating bottom layer is carbon nanotubes, and the carbon nanotube film has a smaller thickness and density, which can save space and reduce the structural mass in the electric heating anti-icing system.

[0046] On the other hand, the present invention provides a method for preparing the above-mentioned photoelectric thermal super-hydrophobic composite film, comprising the following steps:

[0047] S1. Coating a first polydimethylsiloxane solution on a substrate and performing a first pre-curing to obtain a first polydimethylsiloxane base.

[0048] S2. Adhesively attaching an electric heating bottom layer onto the first polydimethylsiloxane base to obtain a carbon nanotube electric heating bottom layer attached to the polydimethylsiloxane base.

[0049] S3. Coat a second polydimethylsiloxane solution on the carbon nanotube electrothermal base layer, perform a second pre-curing to form a second polydimethylsiloxane base, and then evenly spray the silicon dioxide / cobalt mixed solution on the second polydimethylsiloxane base layer and cure to obtain a photothermal super-hydrophobic coating.

[0050] S4. After peeling off the aluminum alloy substrate, the photoelectric thermal super-hydrophobic composite film is prepared.

[0051] Among them, the photothermal super hydrophobic coating (PCoSi-PCNT) is uniformly sprayed on the second polydimethylsiloxane (PDMS) substrate with a silicon dioxide and cobalt dispersion solution, and the SiO2-modified Co particles are deposited on the PDMS surface, so that the coating surface presents a micro-nano rough structure, and the droplets present a high contact angle on the coating surface, which has super hydrophobicity and can slide down under its own gravity or a slight external force, thereby effectively preventing the occurrence of icing behavior, reflecting excellent super hydrophobicity, and Co particles have a photothermal effect. Therefore, the thickness of the second polydimethylsiloxane substrate is not limited, and it only needs to be able to attach SiO2-modified Co particles, so that the coating surface presents a micro-nano rough structure, has super hydrophobicity, can slide down under its own gravity or a slight external force, thereby effectively preventing the occurrence of icing behavior. At an ambient temperature of -15°C, a 30μl droplet completely freezes in 563s, greatly delaying the freezing time. Under simulated sunlight (100mW / cm 2 ), the surface temperature can reach 67.3°C. And the PCoSi-PCNT surface has a rough pit structure, which enhances the light absorption and storage capacity. This not only highlights the excellent performance of PCoSi-PCNT in photothermal effect, but also reduces the energy consumption of aircraft ice control system.

[0052] In some embodiments, the silica / cobalt mixed solution is formed by mixing silica, cobalt and silica in a mass ratio of 1:7.5 to 8.5:1, and the dispersant is anhydrous ethanol.

[0053] In some embodiments, the silicon dioxide / cobalt mixed solution is sprayed on the polydimethylsiloxane at an angle of 45°, the curing temperature is 90°C to 120°C, and the curing time is 8min to 12min. The purpose of spraying at an angle of 45° is to make the sprayed mixed solution more uniform.

[0054] In some embodiments, the first polydimethylsiloxane solution and the second polydimethylsiloxane solution are both formed by mixing polydimethylsiloxane and a curing agent at a mass ratio of 9.5 to 10.5:1, the first pre-curing temperature and the second pre-curing temperature are both 60° C. to 80° C., and the curing time is 8 minutes to 12 minutes. The curing agent is a raw material for catalyzing the curing of polydimethylsiloxane in the conventional technology, and the specific component is a platinum catalyst.

[0055] In addition, the present invention also provides the application of the above-mentioned photoelectric thermal super-hydrophobic composite film in an aircraft anti-icing control system. The present invention is based on the design and research of an aircraft ice control system of a multi-layer functional film, designs an aircraft ice control system, constructs an ice detection and anti-icing integrated device, studies and analyzes the anti-icing performance of the aircraft ice control system, and in some embodiments, such as Figure 2 As shown, the aircraft anti-icing control system includes:

[0056] The photoelectric thermal super-hydrophobic composite film has a photoelectric thermal super-hydrophobic coating layer on which a capacitance sensing electrode, a temperature sensing electrode and a humidity sensing electrode are embedded.

[0057] The anti-icing controller is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film. The anti-icing controller includes an anti-icing controller single chip, an icing sensor module, a temperature sensor module, a humidity sensor module, an electric heating deicing module, a data acquisition control circuit and an external server.

[0058] The electrical signal of the capacitive sensing electrode is connected to the ice sensing module, the electrical signal of the temperature sensing electrode is connected to the temperature sensing module, and the electrical signal of the humidity sensing electrode is connected to the humidity sensing module.

[0059] The icing sensor module, the temperature sensor module and the humidity sensor module are all electrically connected to the anti-icing controller microcontroller, and the anti-icing controller microcontroller is connected to the external server through the data acquisition connection line signal, which is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film and transmit it to the external server. The external server signal is connected to the electric thermal deicing module, and the electric thermal deicing module signal is connected to the photothermal super-hydrophobic coating to heat the photoelectric thermal super-hydrophobic composite film to prevent deicing.

[0060] The electric heating in the anti-icing controller runs automatically, outputs a 3.3V heating voltage, and the surface temperature of PCoSi-PCNT rises from 0°C to 120°C in just 57 seconds. During the continuous operation of the anti-icing controller, the surface temperature is stably controlled between 42°C and 55°C. The anti-icing controller can accurately detect the capacitance change during the freezing process of surface water droplets and start the electric heating in real time. When the electric heating system continues to work, the surface temperature is always maintained between 42°C and 55°C, achieving low energy consumption and high efficiency anti-icing effect.

[0061] The invention is further described below through specific examples.

[0062] Example 1

[0063] A method for preparing a photoelectric thermal super-hydrophobic composite film, such as Figure 1 As shown, the following steps are included:

[0064] S1. The aluminum alloy plate is polished with sandpaper and then cleaned in an ultrasonic cleaner for 10 minutes to remove surface pollutants. It is then rinsed with anhydrous ethanol and finally dried in a nitrogen flow to obtain an aluminum alloy matrix.

[0065] S2. Mix polydimethylsiloxane and curing agent in a mass ratio of 10:1 and add 50 ml of ethyl acetate and stir evenly to form a first polydimethylsiloxane solution. Use a glass rod to evenly spread PDMS on the aluminum alloy plate, put it into a vacuum drying oven, and pre-cure it for the first time at 60°C for 10 minutes to obtain a first polydimethylsiloxane base. The thickness of the first polydimethylsiloxane base is 0.4 mm.

[0066] S3, bonding a carbon nanotube film layer onto the first polydimethylsiloxane base, wherein the thickness of the carbon nanotube film layer is 0.05 mm, to obtain a carbon nanotube electric heating base layer attached to the first polydimethylsiloxane base.

[0067] S4. Mix the first polydimethylsiloxane and the curing agent in a mass ratio of 10:1, add 50 ml of ethyl acetate and stir evenly to form a second polydimethylsiloxane solution, coat the second polydimethylsiloxane solution on the carbon nanotube electric heating bottom layer, put it in a vacuum drying oven, and pre-cure it for a second time at 60°C for 10 minutes to form a second polydimethylsiloxane matrix, mix silicon dioxide, cobalt and anhydrous ethanol in a ratio of 1:8:1, stir with a magnetic stirrer for 30 minutes, use a 0.3mm caliber spray gun at an angle of 45° to the aluminum alloy plate, spray the solution evenly on the second polydimethylsiloxane matrix, put it in a vacuum drying oven, and cure it at 100°C for 10 minutes to obtain a photothermal super hydrophobic coating. The thickness of the photothermal super hydrophobic coating is 0.5 mm.

[0068] S5. After peeling off the aluminum alloy substrate, a photoelectric thermal superhydrophobic composite film is prepared, which is named PCoSi-PCNT.

[0069] Example 2

[0070] A method for preparing a photoelectric thermal super-hydrophobic composite film, such as Figure 1 As shown, the following steps are included:

[0071] S1. The aluminum alloy plate is polished with sandpaper and then cleaned in an ultrasonic cleaner for 10 minutes to remove surface pollutants. It is then rinsed with anhydrous ethanol and finally dried in a nitrogen flow to obtain an aluminum alloy matrix.

[0072] S2. Mix polydimethylsiloxane and curing agent in a mass ratio of 10.5:1 and add 50 ml of ethyl acetate and stir evenly to form a first polydimethylsiloxane solution. Use a glass rod to evenly spread PDMS on the aluminum alloy plate, put it into a vacuum drying oven, and pre-cure it for the first time at 60°C for 10 minutes to obtain a first polydimethylsiloxane base. The thickness of the first polydimethylsiloxane base is 0.5 mm.

[0073] S3, bonding a carbon nanotube film layer onto the first polydimethylsiloxane base, wherein the thickness of the carbon nanotube film layer is 0.06 mm, to obtain a carbon nanotube electric heating base layer attached to the first polydimethylsiloxane base.

[0074] S4. Mix the first polydimethylsiloxane and the curing agent in a mass ratio of 10:1, add 50 ml of ethyl acetate and stir evenly to form a second polydimethylsiloxane solution, coat the second polydimethylsiloxane solution on the carbon nanotube electric heating base, put it in a vacuum drying oven, and pre-cure it for a second time at 60°C for 10 minutes to form a second polydimethylsiloxane base. Mix silica, cobalt and anhydrous ethanol in a ratio of 1:8.5:1, stir with a magnetic stirrer for 30 minutes, use a 0.3mm caliber spray gun at a 45° angle to the aluminum alloy plate, and spray the solution evenly on the second polydimethylsiloxane base. Put it in a vacuum drying oven and cure it at 100°C for 10 minutes to obtain a photothermal super hydrophobic coating. The thickness of the photothermal super hydrophobic coating is 0.6mm.

[0075] S5. After peeling off the aluminum alloy substrate, a photoelectric thermal superhydrophobic composite film is prepared, which is named PCoSi-PCNT.

[0076] Example 3

[0077] A method for preparing a photoelectric thermal super-hydrophobic composite film, such as Figure 1 As shown, the following steps are included:

[0078] S1. The aluminum alloy plate is polished with sandpaper and then cleaned in an ultrasonic cleaner for 10 minutes to remove surface pollutants. It is then rinsed with anhydrous ethanol and finally dried in a nitrogen flow to obtain an aluminum alloy matrix.

[0079] S2. Mix the first polydimethylsiloxane and the curing agent in a mass ratio of 9.5:1 and add 50 ml of ethyl acetate and stir evenly to form a first polydimethylsiloxane solution. Use a glass rod to evenly spread the PDMS on the aluminum alloy plate, put it into a vacuum drying oven, and pre-cure it for the first time at 60°C for 10 minutes to obtain a first polydimethylsiloxane base. The thickness of the first polydimethylsiloxane base is 0.3 mm.

[0080] S3, bonding a carbon nanotube film layer onto the first polydimethylsiloxane base, the thickness of the carbon nanotube film layer is 0.04 mm, to obtain a carbon nanotube electric heating base layer attached to the first polydimethylsiloxane base.

[0081] S4. Mix the first polydimethylsiloxane and the curing agent in a mass ratio of 10:1, add 50 ml of ethyl acetate and stir evenly to form a second polydimethylsiloxane solution, coat the second polydimethylsiloxane solution on the carbon nanotube electrothermal base, put it in a vacuum drying oven, and pre-cure it for a second time at 60°C for 10 minutes. Mix silica, cobalt and anhydrous ethanol in a ratio of 1:7.5:1, stir with a magnetic stirrer for 30 minutes, use a 0.3mm caliber spray gun at a 45° angle to the aluminum alloy plate, and spray the solution evenly on the second polydimethylsiloxane base, put it in a vacuum drying oven, and cure it at 100°C for 10 minutes to obtain a photothermal super hydrophobic coating. The thickness of the photothermal super hydrophobic coating is 0.4mm.

[0082] S5. After peeling off the aluminum alloy substrate, a photoelectric thermal superhydrophobic composite film is prepared, which is named PCoSi-PCNT.

[0083] Comparative Example 1

[0084] A method for preparing a photoelectric thermal super-hydrophobic composite film comprises the following steps:

[0085] S1. The aluminum alloy plate is polished with sandpaper and then cleaned in an ultrasonic cleaner for 10 minutes to remove surface pollutants. It is then rinsed with anhydrous ethanol and finally dried in a nitrogen flow to obtain an aluminum alloy matrix.

[0086] S2. Mix polydimethylsiloxane and curing agent in a mass ratio of 10:1 and add 50 ml of ethyl acetate and stir evenly to form a first polydimethylsiloxane solution. Use a glass rod to evenly spread PDMS on the aluminum alloy plate, put it into a vacuum drying oven, and pre-cure it for the first time at 60°C for 10 minutes to obtain a first polydimethylsiloxane base. The thickness of the first polydimethylsiloxane base is 0.4 mm.

[0087] S3, bonding a carbon nanotube film layer onto the polydimethylsiloxane base, wherein the thickness of the carbon nanotube film layer is 0.05 mm, to obtain a carbon nanotube electric heating base layer attached to the polydimethylsiloxane base.

[0088] S4. Mix the first polydimethylsiloxane and the curing agent in a mass ratio of 10:1, add 50 ml of ethyl acetate and stir evenly to form a second polydimethylsiloxane solution, apply the second polydimethylsiloxane solution on the carbon nanotube electric heating base layer, put it in a vacuum drying oven, and pre-cure it for a second time at 60°C for 10 minutes to form a second polydimethylsiloxane base. Mix cobalt and anhydrous ethanol in a ratio of 8:1, stir with a magnetic stirrer for 30 minutes, use a 0.3mm caliber spray gun at a 45° angle to the aluminum alloy plate, and spray the solution evenly on the second polydimethylsiloxane base. Put it in a vacuum drying oven and cure it at 100°C for 10 minutes to obtain a photothermal super hydrophobic coating. The thickness of the photothermal super hydrophobic coating is 0.5mm.

[0089] S5. After peeling off the aluminum alloy substrate, a photoelectric thermal super-hydrophobic composite film is prepared, which is named PCo-PCNT.

[0090] The morphology and structure of the photoelectric thermal super-hydrophobic composite film prepared in Example 1 and Comparative Example 1 were tested, and the results are as follows:

[0091] Among them, focused ion beam scanning electron microscope FIB-SEM (Zeiss Crossbeam 350) and energy dispersive spectrometer (EDS) were used to characterize the microstructure and detect trace elements.

[0092] The contact angle and rolling angle of the coating surface were tested using a contact angle meter (GYJJ-12). A 5 μL droplet was used for measurement. Five different locations were tested and the average value was taken. The coating was placed in water to observe the silver mirror phenomenon.

[0093] The coating surface was observed using an infrared imager (FLIR-T650sc) under a sun illumination of 100 mW / cm 2 The temperature rise of the light source and the temperature change after the light is turned off are measured. The ambient temperature is maintained at 27°C and the relative humidity is maintained at 40%±1%.

[0094] Figure 3 The surface morphology of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention and Comparative Example 1 is shown in FIG. Figure 3 a to d in the figure are the microstructures of PCo-PCNT at 100μm, 50μm, 10μm and 1μm scales, and e to h are the microstructures of PCoSi-PCNT at 100μm, 50μm, 10μm and 1μm scales. Figure 3 As shown, compared Figure 3a and Figure 3 In the figure, PCoSi-PCNT is rougher and darker than PCo-PCNT. Figure 3 In the morphology of b, the PCo-PCNT surface presents dense rough particles, which reduces the contact between water droplets and the coating surface and presents a certain degree of hydrophobicity; while the PCoSi-PCNT has finer particles, which can be attributed to the fact that the addition of SiO2 further increases its surface roughness, thus helping to improve hydrophobicity. Figure 3 c and Figure 3 In the morphology of g, PCoSi-PCNT presents a deeper pit structure relative to PCo-PCNT, and light can be refracted multiple times inside the pit, thereby optimizing the light storage effect. Figure 3 d and Figure 3 The morphology of h in the figure further magnifies the particles of PCoSi-PCNT and PCo-PCNT. It is obvious that particles of different sizes on the surface of PCoSi-PCNT are combined with each other, which is more dense, presenting a rough structure at the micro-nano level and better hydrophobicity. The characterization results reveal the differences in surface properties of PCoSi-PCNT compared to PCo-PCNT at different scales.

[0095] Figure 4 This is the elemental EDS layering diagram of the photoelectric thermal super-hydrophobic composite film of comparative example 1 of the present invention. Figure 5 This is the element EDS layering diagram of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention. Figure 4 and Figure 5As shown, the distribution of C, O, Co and Si of different colors in PCo-PCNT and PCoSi-PCNT at 100μm is shown by element detection. In the PCo-PCNT coating, there are mainly three elements, C, O and Co, which are evenly distributed on the surface of the PCo-PCNT coating. In PDMS, the distribution of C and O elements is cross-linked. PDMS is composed of silicon and oxygen atoms arranged alternately to form a silicon-oxygen bond, and each silicon atom is connected to two methyl groups. Therefore, in PDMS, the methyl group of the C element is distributed around the Si-O chain, while the O element is mainly present in the Si-O bond. On the whole, the C and O elements are interlaced in the chemical structure of PDMS. Therefore, the C and O elements account for 14.7% and 4.7% of the entire coating, respectively, and the remaining 80.5% is the Co element. It can be seen that Co is the main element component in the PCo-PCNT coating and is densely distributed. Since the Co sprayed on the surface of the coating has a certain roughness, Co can provide hydrophobicity. In the PCoSi-PCNT coating, there are four elements, C, O, Co and Si, which are evenly distributed, accounting for 27.3%, 18.2%, 45.3% and 9.2% respectively. It is observed that after the introduction of SiO2, the relative content of Co on the PCoSi-PCNT surface decreases, and the relative content of C, O and Si increases, indicating that the SiO2-modified Co particles are successfully deposited on the PDMS surface, making the coating surface rougher than PCo-PCNT. The droplets present a high contact angle on the coating surface and can slide down under their own gravity or slight external force, thereby effectively preventing the occurrence of icing behavior, reflecting excellent superhydrophobicity.

[0096] A 20 mm × 20 mm area was taken from each of the PDMS, PCo-PCNT, and PCoSi-PCNT coating surfaces for contact angle measurement. Figure 6 The hydrophobicity diagram of the photoelectric thermal super hydrophobic composite film of the present invention PDMS, Example 1 and Comparative Example 1. Figure 6 As shown, the hydrophobicity of PDMS, PCo-PCNT and PCoSi-PCNT increases in turn, among which PCoSi-PCNT exhibits excellent hydrophobic performance, with a contact angle (CA) and sliding angle (SA) of 157° and 3°, respectively.

[0097] The above SEM morphology analysis shows that the introduction of SiO2 significantly increases the roughness of the micro-nanostructure, thereby effectively improving the hydrophobicity of the coating. The three samples were placed in water for comparative observation. Figure 7 The silver mirror phenomenon diagram of the photoelectric thermal super hydrophobic composite film of the present invention PDMS, Example 1 and Comparative Example 1. Figure 7As shown, it can be seen that PDMS has no obvious changes. Co in PCo-PCNT itself is hydrophobic, so there are a large number of bubbles on the surface. The surface of PCoSi-PCNT has a silver mirror luster. This is because the hydrophobic surface captures the air layer, causing a large number of bubbles to attach to the surface. The stronger the hydrophobicity, the stronger the ability to capture bubbles. When the surface reaches super-hydrophobicity, bubbles will cover the surface of the coating, and due to the reflection effect of light, a silver mirror luster will appear. This further proves that PCoSi-PCNT has the strongest hydrophobicity, followed by PCo-PCNT, and PDMS has the weakest.

[0098] Under the condition of maintaining the room temperature at about 27℃, PDMS, PCo-PCNT and PCoSi-PCNT were taken in 20mm×20mm sizes and placed on the self-built insulation foam. The light simulation lamp was turned on and the light intensity was 100mW / cm 2 , use an infrared camera to observe the temperature rise of the surface, take data every 12 seconds, and the results are as follows Figure 8 shown. Figure 8 The infrared imaging diagram of the surface temperature rise of the PDMS, Example 1 and Comparative Example 1 photoelectric thermal super hydrophobic composite film of the present invention. Figure 8 As shown, after 8 minutes of illumination, the surface temperature of the PDMS coating was only 38.2°C, while the cobalt in the PCo-PCNT and PCoSi-PCNT coatings had a photothermal effect, and the surface temperatures reached 58.5°C and 67.3°C, respectively.

[0099] Fig. 9 The surface temperature rise and cooling curves of the PDMS, Example 1 and Comparative Example 1 photoelectric thermal super hydrophobic composite film of the present invention are shown in FIG. The surface temperature rise and drop data of each coating are shown in FIG. Fig. 9 As shown in the figure, when the light simulation lamp was turned off at the 8th minute, the surface temperature of PDMS dropped rapidly, decreasing by 7.8°C in 12 seconds and reaching room temperature 27°C after 60 seconds. The temperature drop rate of PCo-PCNT was second, decreasing by 2.2°C in 12 seconds and reaching room temperature 27°C after 156 seconds. The temperature drop rate of PCoSi-PCNT was the slowest, decreasing by 0.5°C in 12 seconds and reaching room temperature 27.4°C after 192 seconds.

[0100] The photoelectric thermal super-hydrophobic composite film prepared in Example 1 is used in an aircraft anti-icing control system. Figure 2As shown, the aircraft anti-icing control system includes: a photoelectric thermal super-hydrophobic composite film, in which the photoelectric thermal super-hydrophobic coating of the photoelectric thermal super-hydrophobic composite film is embedded with a capacitive sensing electrode, a temperature sensing electrode and a humidity sensing electrode; an anti-icing controller for detecting the surface icing state of the photoelectric thermal super-hydrophobic composite film, the anti-icing controller includes an anti-icing controller single-chip microcomputer (MCU), an icing sensor module, a temperature sensor module, a humidity sensor module, an electric thermal deicing module, a data acquisition control circuit and an external server; the capacitive sensing electrode electrical signal is connected to the icing sensor module, and the The temperature sensing electrode electrical signal is connected to the temperature sensing module, and the humidity sensing electrode electrical signal is connected to the humidity sensing module; the ice sensing module, the temperature sensing module and the humidity sensing module are all electrically connected to the anti-icing controller microcontroller, and the anti-icing controller microcontroller is connected to the external server through the data acquisition connection line signal, which is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film and transmit it to the external server, the external server signal is connected to the electric thermal deicing module, and the electric thermal deicing module signal is connected to the photothermal super-hydrophobic coating, so that the photoelectric thermal super-hydrophobic composite film is heated to prevent deicing.

[0101] Among them, the capacitive sensing electrode, temperature sensing electrode and humidity sensing electrode are embedded in the photothermal super-hydrophobic coating surface of the photothermal super-hydrophobic composite film, and the wire interface is led out with conductive silver glue; finally, it is placed in a vacuum drying oven for curing for 120 minutes at a curing temperature of 150°C. After curing, it is naturally cooled at room temperature.

[0102] The capacitive sensing electrode is a forked comb electrode, model FDC2214, with an electrode thickness of 0.02 mm and a distance of 100 μm between adjacent pairs of forked comb electrodes. There are a total of 10 pairs of forked comb electrodes, which communicate with the main control chip through the IC protocol and cooperate with the forked comb electrodes to monitor the capacitance changes during the freezing process.

[0103] The model of the temperature sensing electrode is PT-100, the temperature sensing module is the temperature measurement chip MAX31865, and the SPI protocol is used to monitor the experimental environment temperature through the temperature sensing electrode.

[0104] The model of humidity sensing electrode is HR202L. The humidity sensing module is humidity measurement chip HTU21D, and the humidity is monitored through humidity sensing electrode via I2C protocol.

[0105] The capacitive sensing electrodes, temperature sensing electrodes and humidity sensing electrodes embedded in the photoelectric thermal super-hydrophobic composite film are respectively connected to the ice sensing module, temperature sensing module and humidity sensing module through wires. These components are connected to the anti-icing controller single-chip computer through wires. The anti-icing controller single-chip computer obtains various parameters on the surface of the multi-layer functional film by interacting with each module, thereby judging the icing situation. And it is transmitted to the external server. The external server is responsible for receiving the data of the anti-icing controller receiving the single-chip computer and using the serial port for communication. It has strong anti-interference ability and high reliability. The external server signal is connected to the electric heating deicing module to heat the photoelectric thermal super-hydrophobic composite film for anti-icing. The anti-icing controller is used to monitor the capacitance change and automatically turn on the heating module to ensure that the surface of the multi-layer film is maintained at the optimal working temperature of 42℃~55℃ at different humidity. Because the total power of the anti-icing controller is small, the external server is responsible for providing a 5V DC power supply, which is then converted into a 3.3V power supply by the power module to power the entire anti-icing controller.

[0106] The special arrangement of protons in ice crystals allows ice molecules to be redirected under the influence of an external electric field, which in turn causes polarization, which is manifested as a change in the dielectric properties of ice. Studies on the dielectric constants of water and ice have shown that there are obvious differences between them. This change in properties can be reflected macroscopically as a change in dielectric capacitance. By detecting this change, water and ice can be detected and distinguished.

[0107] When the sensing electrode structure is determined, the capacitance is closely related to the relative static dielectric constant of the material. As water gradually turns into ice, the ratio of ice to air between the sensing electrodes increases. Since the dielectric constant of ice is greater than that of air, the capacitance value tends to increase. Therefore, by monitoring the capacitance value changes on the electrodes, the current freezing situation can be reflected.

[0108] A cooling table was built in the cryogenic chamber to conduct an icing experiment. The capacitance change of the sensing electrode was detected by changing the relative humidity. The temperature of the cryogenic chamber was maintained at 0°C and the temperature of the cooling table was maintained at -15°C.

[0109] In the cryogenic chamber, the temperature is set to 0°C, the multifunctional film is placed on a refrigeration table for testing, and the icing test chamber temperature is set to -15°C. The detection electrode is tested at relative humidity of 20%, 30%, 40%, 50%, 60%, and 70% RH, and the sensor measures capacitance, temperature, and humidity at the same time.

[0110] Fig.10 This is a curve showing the change of the ice capacitance value of the photoelectric thermal super-hydrophobic composite film of Example 1 of the present invention over time under different relative humidity environments, wherein: Fig.10a in the figure is the change curve from 0s to 700s, the small figure in the lower left corner of a is the change curve from 0 to 50s, b is the change curve from 30s to 100s, and c is the change curve from 330s to 470s. Fig.10 As shown in a and the small figure in the lower left corner of a, the capacitance value remains stable at about 72pF from 0s to 25s. Between 25s and 35s, the dielectric constant of air decreases as the temperature decreases. At low temperatures, the thermal motion of gas molecules slows down, the collision frequency between molecules decreases, and the polarization degree of gas molecules decreases, thereby reducing the dielectric constant. Therefore, a decrease in the dielectric constant will lead to a decrease in the capacitance value.

[0111] like Fig.10 As shown in b, during the period of 35s to 100s, the capacitance values ​​under different humidity levels all rise rapidly. The increase in capacitance can be explained by the formation of small water droplets of different sizes on the detection electrode. The water vapor generated by the humidifier adheres to the surface of the detection electrode and forms small water droplets through the hydrophilicity between the liquids. Because the air on the detection electrode is replaced by liquid, the relative static dielectric constant of water is 80 times that of air, which leads to an increase in capacitance.

[0112] like Fig.10 As shown in a in FIG, during the period from 100s to 330s, the water droplets cover the detection electrode, causing the detected capacitance value to remain at a certain value. At this time, the water droplets are in a supercooled water state. The water droplets are cooled to -15°C but still remain in liquid state, and there are not enough ice nuclei to induce freezing.

[0113] like Fig.10 As shown in c, during the period of 330s to 360s, the water droplets formed on the sensing electrode have different sizes and the time when the ice nuclei appear is also different at different humidity. The higher the humidity, the later the ice nuclei form. In the freezing environment with humidity of 20%, 30%, 40%, 50%, 60% and 70% RH, the time when ice nuclei appear on the surface of the detection electrode is 330s, 335s, 340s, 345s, 354s and 360s respectively. After the ice nuclei are formed, the capacitance value will suddenly drop, dendritic ice crystals will grow on the surface, and the surface of the water droplets will be slightly deformed. The ice nuclei inside the water droplets begin to form ice crystals, which will gradually grow inside the water droplets until the entire water droplet is completely frozen. Correspondingly, the higher the environmental humidity, the longer it takes to completely freeze. When the relative humidity is below 70% RH, when it is completely frozen, since there are still gaps between the interdigital electrode gaps, water droplets will gradually form ice in the gaps, and the capacitance value will rise slightly.

[0114] Electric heating is an active deicing method with the advantages of high efficiency and environmental protection. The anti-icing controller automatically controls the electric heating to achieve low-energy anti-icing. Fig.11The surface temperature rise curves of the deicing control electric heating system under different voltages are shown below: Fig.11 a is the temperature rise curve of the surface at 3.3V and 5V, b is the temperature rise curve of the surface when the icing condition is reached and the output voltage is 3V, and c is the curve of the surface temperature controlled in the range of 42℃~55℃. Fig.11 As shown, the anti-icing controller can output 3.3V and 5V voltages at room temperature 27°C. Fig.11 Figure a shows the electric heating performance of the carbon nanotube film. When the ambient temperature is 27℃, the low-temperature chamber starts to cool. Through program design, when the ambient temperature is 0℃, that is, 50s, the electric heating function is automatically turned on, and the surface temperature of the multilayer functional film rises rapidly with time. The heating speed and the maximum temperature reached by the 5V voltage are higher than those of the 3.3V voltage. The 3.3V voltage reaches about 110℃ in 110s, and then slowly rises and remains at 120℃. The 5V voltage reaches 130℃ in 95s, and then slowly rises and remains at 140℃. In order to meet the temperature requirements of the anti-icing function and reduce energy consumption, the 3.3V voltage is selected as the heating voltage for electric heating.

[0115] The ice detector collects the capacitance changes of the ice detection sensor under different relative humidity environments, and uses the time when ice nuclei appear as the icing standard. When the anti-icing controller detects these ice points, it automatically turns on the electric heating, such as Fig.11 As shown in b. In the low-temperature room, the temperature of the icing test box is set to -15°C, and a multi-layer functional film is placed in it. Because in a high humidity environment, the air contains more water vapor, which will affect heat transfer and slow down the heat transfer rate during heating or cooling. Therefore, the higher the humidity, the slower the ambient temperature drops between 0s and 150s. From 330s to 500s, when each freezing point is reached, the electric heating is turned on. The higher the humidity, the slower the heating efficiency. In the end, the surface of the multi-layer functional film reaches 120°C. The most suitable surface temperature of the aircraft electric thermal anti-icing system during continuous operation is between 42°C and 55°C, and a PTC heating module is used to control the temperature during heating. As Fig.11 As shown in Figure c, at the beginning of the heating stage, the temperature rise trend is consistent for temperature-controlled heating and non-temperature-controlled heating. The surface temperature of the multilayer functional membrane rises rapidly from 0°C to the 55°C shutoff temperature of the programmed temperature control range, and then the heating stops. The surface temperature of the multilayer functional membrane begins to drop. When the temperature drops to the lower limit of the programmed temperature control range of 42°C, it starts to heat again. After the temperature rises rapidly to 55°C again, it is heated in a reciprocating cycle. This improves the anti-icing performance of the electric heating system, minimizes the demand for aircraft energy, and realizes low-energy anti-icing of aircraft.

[0116] PDMS, PCo-PCNT and PCoSi-PCNT were placed in an ice test chamber at -15°C and 40% relative humidity, and 30 μL of water was dripped into each chamber. The freezing process was recorded with a camera. Complete freezing was judged by the formation of ice tips by water droplets. Fig.12 This is a test diagram of the anti-icing performance of the photoelectric thermal super-hydrophobic composite film of the present invention PDMS, Example 1 and Comparative Example 1, wherein: Fig.12 a is a diagram showing the freezing process of water droplets on PDMS, PCo-PCNT and PCoSi-PCNT, b is a diagram showing the electric heating anti-icing in Example 1, and c is the electric heating performance when the water droplets in Example 1 are completely frozen.

[0117] The freezing process Fig.12 As shown in a, the PDMS coating showed no obvious changes after 65s. The bottom began to freeze at 147s. The water droplets became no longer transparent at 198s, and the water droplets completely froze to form ice tips at 236s. PCo-PCNT suddenly began to freeze at 294s. The water droplets began to become turbid at 342s and completely froze at 461s. The complete freezing time was 225s later than that of PDMS. The water droplets of PCoSi-PCNT began to freeze at 392s. The water droplets became turbid and opaque at 486s. They were completely frozen at 563s to form ice tips. The complete freezing time of PCoSi-PCNT was 102s later than that of PCo-PCNT and 327s later than that of PDMS. This result can be explained from the aspects of roughness and heat transfer coefficient. The PDMS coating is relatively flat, and the contact area between the droplets and the surface is larger; the rough micro-nanostructure of the PCo-PCNT surface has a certain air gap, and the heat transfer coefficient is lower than that of PDMS, which delays the freezing time; PCoSi-PCNT is rougher, so that a tiny air cushion is formed between the droplets and the coating surface, the heat transfer coefficient becomes smaller, and the freezing is delayed most significantly.

[0118] When the anti-icing controller detects the presence of ice cores, it automatically turns on the electric heating anti-icing function. Fig.12 As shown in b, the time from the appearance of ice nuclei to complete melting is 45s. When the multilayer functional membrane is completely frozen, the electric heating is turned on. Fig.12 As shown in Figure c, the time for complete ice melting is 637 seconds, and the time from electric heating on to ice melting is 76 seconds. The aircraft ice control system passively prevents ice by relying on the photothermal superhydrophobicity of the coating before ice nuclei appear, and automatically turns on electric heating to prevent water droplets from freezing when ice nuclei appear.

[0119] In summary, the surface CA of the photoelectric thermal superhydrophobic composite film PCoSi-PCNT prepared by the present invention reaches 157°. At an ambient temperature of -15°C, a 30μl droplet completely freezes in 563s, greatly delaying the freezing time. 2), the surface temperature can reach 67.3°C. And the PCoSi-PCNT surface has a rough pit structure, which enhances the light absorption and storage capacity. This not only highlights the excellent performance of PCoSi-PCNT in photothermal effect, but also reduces the energy consumption of aircraft ice control system.

[0120] The aircraft ice control system has excellent sensing performance and long-term sensing stability, and can judge the icing situation according to the capacitance change caused by the surface icing process under different relative humidity environments. By monitoring and recording the capacitance value at the corresponding icing, the electric heating system is automatically turned on. The present invention provides a simple method that combines ice detection with active and passive anti-icing, providing an effective solution for future icing problems, making anti-icing more efficient, reducing energy consumption and improving the stability of anti-icing.

[0121] The electric heating in the anti-icing controller runs automatically, outputs a heating voltage of 3.3V, and the surface temperature of PCoSi-PCNT rises from 0℃ to 120℃ in just 57s. During the continuous operation of the anti-icing controller, the surface temperature is stably controlled between 42℃ and 55℃.

[0122] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0123] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A photoelectric thermal super-hydrophobic composite film, characterized in that: The composite film includes a first polydimethylsiloxane substrate and an electrothermal bottom layer attached to the first polydimethylsiloxane substrate, and a photothermal super-hydrophobic coating is attached to the electrothermal bottom layer. The photothermal super-hydrophobic coating is a mixed coating formed by depositing silicon dioxide and cobalt on the surface of the second polydimethylsiloxane substrate, and the second polydimethylsiloxane substrate is attached to the electrothermal bottom layer.

2. The photoelectric thermal super-hydrophobic composite film according to claim 1, characterized in that: The thickness of the first polydimethylsiloxane base is 0.3 mm to 0.5 mm, the thickness of the electrothermal base layer is 0.04 mm to 0.06 mm, and the thickness of the photothermal superhydrophobic coating is 0.4 mm to 0.6 mm.

3. The photoelectric thermal super-hydrophobic composite film according to claim 1, characterized in that: The electric heating material used in the electric heating bottom layer is carbon nanotube, graphene or MXene material.

4. A method for preparing the photoelectric thermal super-hydrophobic composite film according to any one of claims 1 to 3, characterized in that: The following steps are involved: Coating a first polydimethylsiloxane solution on a substrate, and performing a first pre-curing to obtain a first polydimethylsiloxane base; Adhesively attaching an electric heating bottom layer to the first polydimethylsiloxane bottom layer to obtain an electric heating bottom layer; A second polydimethylsiloxane solution is coated on the electrothermal base layer, and pre-cured for a second time to form a second polydimethylsiloxane base layer, and then a silicon dioxide / cobalt mixed solution is evenly sprayed on the second polydimethylsiloxane base layer, and cured to obtain a photothermal super-hydrophobic coating; That is, the photoelectric thermal super-hydrophobic composite film is prepared.

5. The method for preparing the photoelectric thermal super-hydrophobic composite film according to claim 4, characterized in that: The silicon dioxide / cobalt mixed solution is formed by mixing silicon dioxide, cobalt and a dispersant in a mass ratio of 1:7.5 to 8.5:1, and the dispersant is anhydrous ethanol.

6. The method for preparing the photoelectric thermal super-hydrophobic composite film according to claim 4, characterized in that: The silicon dioxide / cobalt mixed solution is sprayed on the second polydimethylsiloxane at an angle of 45 degrees, and the curing temperature is 90° C. to 120° C. and the curing time is 8 min to 12 min.

7. The method for preparing the photoelectric thermal super-hydrophobic composite film according to claim 4, characterized in that: The first polydimethylsiloxane solution and the second polydimethylsiloxane solution are both formed by mixing polydimethylsiloxane and a curing agent in a mass ratio of 9.5 to 10.5:

1. The temperatures of the first pre-curing and the second pre-curing are both 60° C. to 80° C., and the curing time is both 8 min to 12 min.

8. Use of the photoelectric thermal super-hydrophobic composite film according to claims 1-3 in an aircraft anti-icing control system.

9. The use according to claim 8, characterized in that: Aircraft anti-icing control system includes: A capacitive sensing electrode, a temperature sensing electrode and a humidity sensing electrode are embedded in the photothermal super-hydrophobic coating of the photothermal super-hydrophobic composite film; An anti-icing controller, used for detecting the surface icing state of the photoelectric thermal super-hydrophobic composite film, the anti-icing controller comprises an anti-icing controller single chip computer, an icing sensor module, a temperature sensor module, a humidity sensor module, an electric heating deicing module, a data acquisition control circuit and an external server; The electrical signal of the capacitive sensing electrode is connected to the ice sensing module, the electrical signal of the temperature sensing electrode is connected to the temperature sensing module, and the electrical signal of the humidity sensing electrode is connected to the humidity sensing module; The icing sensor module, the temperature sensor module and the humidity sensor module are all electrically connected to the anti-icing controller microcontroller, and the anti-icing controller microcontroller is connected to the external server through the data acquisition connection line signal, which is used to detect the surface icing state of the photoelectric thermal super-hydrophobic composite film and transmit it to the external server. The external server signal is connected to the electric thermal deicing module, and the electric thermal deicing module signal is connected to the photothermal super-hydrophobic coating to heat the photoelectric thermal super-hydrophobic composite film to prevent deicing.

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