An electric heating and wave-penetrating integrated deicing film, a preparation method and application thereof

Abstract

The present application relates to the technical field of electromagnetic wave-transparent material, and particularly relates to an ice-preventing film integrating electric heating and wave-transparent, a preparation method and application thereof.The ice-preventing film integrating electric heating and wave-transparent provided by the present application comprises a polymer matrix, and nano-scale conductive functional particles and micro-scale wave-transparent functional particles dispersed in the polymer matrix; the polymer matrix is an electromagnetic wave-transparent material.The electric conductivity of the ice-preventing film can be controlled in a range of 5-200 S / m, which is suitable for a large range of ice-preventing needs, and the wave-transparent rate can reach more than 60% in a frequency band of 0.3-18 GHz, which meets the compatible needs of electric heating ice-preventing and electromagnetic wave-transparent of a stealth aircraft, a radar cover and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic wave-transparent materials, and particularly relates to an ice-preventing film integrating electric heating and wave transmission, a preparation method and application thereof. BACKGROUND

[0002] The icing on the surface of the wing, radar cover and other equipment of a stealth aircraft can seriously affect the safe operation of the equipment, and effective ice-preventing means are needed to ensure that the equipment is not disturbed by icing when working in the flight process or low-temperature environment. However, the stealth aircraft and radar cover are made of composite material structural parts, and cannot use hot air anti-icing, mechanical anti-icing and other methods to remove ice from the surface. The traditional electric heating film causes strong electromagnetic reflection, affecting the stealth performance of the aircraft or the electromagnetic transmission performance of the radar, and a compatible ice-preventing material that can simultaneously realize electric heating and electromagnetic wave transmission is urgently needed to solve the ice-preventing problem of the stealth aircraft and radar cover and the like. SUMMARY

[0003] The present application aims to provide an ice-preventing film integrating electric heating and wave transmission, a preparation method and application thereof, which can be a compatible ice-preventing material that can simultaneously realize electric heating and electromagnetic wave transmission, and solve the ice-preventing problem of the stealth aircraft and radar cover and the like.

[0004] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0005] The present application provides an ice-preventing film integrating electric heating and wave transmission, comprising a polymer matrix and nanoscale conductive functional particles and micrometer-scale wave-transparent functional particles dispersed in the polymer matrix.

[0006] The polymer matrix is an electromagnetic wave-transparent material.

[0007] Preferably, the mass ratio of the polymer matrix, nanoscale conductive functional particles and micrometer-scale wave-transparent functional particles is 1:(0.05-0.3):(0.1-1).

[0008] Preferably, the polymer matrix comprises one or more of polyurethane, epoxy resin and silicone rubber.

[0009] Preferably, the nanoscale conductive functional particles have a particle size of 1-100 nm.

[0010] Preferably, the nanoscale conductive functional particles comprise one or more of carbon material, metal material and intrinsically conductive polymer material.

[0011] Preferably, the micrometer-scale wave-transparent functional particles have a particle size of 1-50 μm.

[0012] Preferably, the material of the micrometer-sized wave-transparent functional particles comprises inorganic non-conductive materials and / or organic non-conductive materials;

[0013] The inorganic non-conductive materials comprise one or more of silica microspheres, hollow glass microbeads, titanium dioxide microspheres and glass fiber short filaments;

[0014] The organic non-conductive materials comprise one or more of polymethyl methacrylate microspheres, polystyrene microspheres and polymer fiber short filaments.

[0015] The application also provides a preparation method of the anti-icing film as described above, comprising the following steps:

[0016] The polymer matrix, the nanometer-sized conductive functional particles and a solvent are first mixed to obtain a conductive dispersion liquid;

[0017] The conductive dispersion liquid and the micrometer-sized wave-transparent functional particles are second mixed to obtain a film material dispersion liquid;

[0018] The film material dispersion liquid is formed into a film to obtain the anti-icing film.

[0019] Preferably, the solvent comprises one or more of toluene, xylene, ethanol, acetone, ethyl acetate and water;

[0020] The mass ratio of the polymer matrix to the solvent is 1:(5-20).

[0021] The application also provides an application of the electrically heated anti-icing film as described above or the anti-icing film prepared by the preparation method as described above to the windward surface of a radar cover or a stealth aircraft.

[0022] The application provides an electrically heated and wave-transparent integrated anti-icing film, comprising a polymer matrix and nanometer-sized conductive functional particles and micrometer-sized wave-transparent functional particles dispersed in the polymer matrix; the polymer matrix is an electromagnetic wave-transparent material. The electric conductivity of the anti-icing film can be arbitrarily adjusted in the range of 5-200 S / m, which is suitable for a large range of anti-icing needs, and the wave-transparent rate can all reach more than 60% in the frequency band of 0.3-18 GHz, which meets the compatible needs of electrically heated anti-icing and electromagnetic wave-transparent of a stealth aircraft, a radar cover and the like. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Fig. 1 is a structural schematic diagram of the electrically heated and wave-transparent integrated anti-icing film of the application; wherein, 1 is an integrated anti-icing film, 2 is micrometer-sized wave-transparent functional particles, 3 is nanometer-sized conductive functional particles, 4 is a polymer matrix material, E is an electric field, H is an electromagnetic field, and U+ is a positive electrode of the electric field.

[0024] Figure 2The schematic diagram of the function mode of the electric heating and wave-transparent function of the anti-icing film; wherein, 1' is a micron-scale wave-transparent aperture, 2' is a micron-scale net-shaped conductive structure (consisting of a polymer matrix and nano-scale conductive functional particles dispersed in the polymer matrix), 3' is a nano-conductive network (formed by self-assembly of the nano-scale conductive functional particles), 4' is a nano-scale wave-transparent aperture (formed by filling of the polymer matrix), 5' is four possible electromagnetic wave paths, 6' is two possible current paths, E is an electric field, and H is an electromagnetic field;

[0025] Figure 3 The self-assembly form of the micron-scale wave-transparent functional particles in the anti-icing film; wherein, 1" is a single-size homogeneous self-assembly, 2" is a size-gradient layered self-assembly, and 3" is a size-gradient mixed self-assembly.

[0026] Figure 4 The preparation flowchart of the anti-icing film; wherein, A is a polymer matrix, B is a nano-scale conductive functional particle, C is a conductive dispersion liquid, D is a micron-scale wave-transparent functional particle, F is a film material dispersion liquid, E is an electric field, H is an electromagnetic field, U+ is a positive electrode of the electric field, 6-1 is a spraying method, 6-2 is a blade coating method, 6-3 is a pouring method, and 7 is an anti-icing film.

[0027] Figure 5 The wave-transparent coefficient curve of the anti-icing film of Example 1 of the present application at a frequency of 0.3-18 GHz;

[0028] Figure 6 The wave-transparent coefficient curve of the anti-icing film of Example 2 of the present application at a frequency of 0.3-18 GHz;

[0029] Figure 7 The wave-transparent coefficient curve of the anti-icing film of Example 3 of the present application at a frequency of 0.3-18 GHz. DETAILED DESCRIPTION

[0030] The present application provides an anti-icing film with integrated electric heating and wave-transparent functions, comprising a polymer matrix, nano-scale conductive functional particles and micron-scale wave-transparent functional particles dispersed in the polymer matrix.

[0031] The polymer matrix is an electromagnetic wave-transparent material.

[0032] In the present application, the thickness of the anti-icing film is preferably ≤1 mm, and the anti-icing film is steplessly regulated in the range of 10 μm-1 mm.

[0033] In the present application, the mass ratio of the polymer matrix, the nanoscale conductive functional particles and the micrometer scale wave-transparent functional particles is preferably 1:(0.05-0.3):(0.1-1), more preferably 1:(0.1-0.25):(0.2-0.8), and most preferably 1:(0.15-0.2):(0.3-0.6).

[0034] In the present application, the polymer matrix preferably comprises one or more of polyurethane, epoxy resin and silicone rubber. When the polymer matrix is two or more of the above-mentioned specific choices, the present application does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0035] In the present application, the nanoscale conductive functional particles preferably have a particle size of 1-100 nm, more preferably 5-80 nm, and most preferably 10-50 nm.

[0036] In the present application, the nanoscale conductive functional particles comprise one or more of carbon material, metal material and intrinsically conductive polymer material; the carbon material preferably comprises one or more of carbon nanotube, graphene, nano-graphite powder and carbon nanofiber; the metal material preferably comprises nano-copper powder and / or nano-silver powder; the intrinsically conductive polymer material preferably comprises one or more of polyacetylene, polypyrrole, polythiophene and polyaniline; when the nanoscale conductive functional particles are two or more of the above-mentioned specific choices, the present application does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0037] In the present application, the micrometer scale wave-transparent functional particles preferably have a particle size of 1-50 μm, more preferably 10-40 μm, and most preferably 20-30 μm.

[0038] In the present application, the micrometer scale wave-transparent functional particles preferably comprise inorganic non-conductive material and / or organic non-conductive material; the inorganic non-conductive material preferably comprises one or more of silica microspheres, hollow glass microbeads, titanium dioxide microspheres and glass fiber short filaments; the organic non-conductive material preferably comprises one or more of polymethyl methacrylate microspheres, polystyrene microspheres and polymer fiber short filaments; when the micrometer scale wave-transparent functional particles are two or more of the above-mentioned specific choices, the present application does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0039] In the present application, the structure of the electric heating and wave-transparent integrated anti-icing film is shown in the schematic diagram Figure 1As shown, the whole surface of the anti-icing film is a continuous film, and a triple local enlarged schematic view from the thickness direction shows the schematic case of the internal structure of the coating. The polymer matrix serves as the main material of the film and provides mechanical properties such as strength and adhesion. The nanoscale conductive functional particles are uniformly dispersed in the polymer matrix material and self-assembled under the multiple actions of the van der Waals force between the nanoscale conductive functional particles and the micrometer-scale wave-transparent functional particles in the system and the viscous force of the polymer matrix material. The self-assembly form is as shown in the figure Figure 3 As shown, the self-assembly mainly includes three types: single-size homogeneous self-assembly, which is formed by self-assembly of micrometer-scale wave-transparent particles of a single size, and usually forms a hexagonal distribution similar to close packing; size gradient layered self-assembly, which is formed by self-assembly of mixed micrometer-scale wave-transparent functional particles of different sizes, and can form a layered self-assembly structure with a size gradient by controlling the viscosity of the film material, the solidification time, centrifugation, etc.; and size gradient mixed self-assembly, which is formed by self-assembly of mixed micrometer-scale wave-transparent functional particles of different sizes, and each size of particles is uniformly dispersed in the polymer matrix to form a mixed uniform multi-level self-assembly structure. These different self-assembly structures can regulate the spatial shape of the network conductive structure, and then affect the shape of the conductive path and the wave-transparent path, and regulate the conductive heating performance and the electromagnetic wave-transparent performance. Under the action of percolation effect and tunnel effect, a conductive network is formed, thereby having the conductive heating performance and realizing the electric heating anti-icing function. At the same time, the nanoscale conductive functional particles are not in a dense structure, but there are nanopores between them, which provide nanopore channels for electromagnetic waves. The micrometer-scale wave-transparent functional particles are uniformly dispersed in the polymer matrix material and self-assembled under the multiple actions of the van der Waals force between the micrometer-scale wave-transparent functional particles and the nanoscale conductive functional particles in the system and the viscous force of the polymer matrix, thereby forming close-packed micrometer wave-transparent pores, and cooperating with the nanopore channels to form a micro-nano secondary electromagnetic wave-transparent channel, thereby greatly improving the wave-transparent performance.

[0040] In the present application, the action mode of the conductive heating and electromagnetic wave-transparent function of the anti-icing film is as shown in the figure Figure 2 As shown in the figure Figure 2It can be known that, in the anti-icing film system, the micrometer-sized wave-transparent pores formed by the micrometer-sized wave-transparent functional particles self-assembled form a non-conductive area after the polymer matrix and the nanometer conductive functional particles are pushed away, which provides a micrometer-sized path for the electromagnetic wave to penetrate the film material; meanwhile, the polymer matrix and the nanometer conductive functional particles dispersed inside are pushed away to form a micrometer-sized network conductive structure, which provides a path for the current; from the nanometer scale, the network conductive structure is internally formed by the nanometer-sized conductive network formed by the nanometer-sized conductive functional particles self-assembled, and a large number of nanometer-sized pores exist between the nanometer conductive functional particles, which are filled by the polymer matrix to form nanometer-sized wave-transparent pores; the nanometer-sized wave-transparent pores and the micrometer-sized wave-transparent pores are mutually coordinated to form a micrometer-nanometer two-level wave-transparent pore structure, which provides a two-level path for the electromagnetic wave to penetrate the film material, and greatly improves the wave-transmitting performance.

[0041] In the present application, the conductivity of the anti-icing film is low, and the electromagnetic wave-transmitting rate can reach more than 60% in the frequency band of 0.3-18 GHz.

[0042] The present application also provides a preparation method of the anti-icing film according to the above technical solution, which comprises the following steps:

[0043] The polymer matrix, the nanometer-sized conductive functional particles and the solvent are first mixed to obtain a conductive dispersion liquid;

[0044] The conductive dispersion liquid and the micrometer-sized wave-transparent functional particles are secondly mixed to obtain a film material dispersion liquid;

[0045] The film material dispersion liquid is formed into a film to obtain the anti-icing film (as shown in the figure). Figure 4

[0046] In the present application, all the raw materials for preparation are commercially available products well known to those skilled in the art, unless otherwise specified.

[0047] The polymer matrix, the nanometer-sized conductive functional particles and the solvent are first mixed to obtain a conductive dispersion liquid.

[0048] In the present application, the solvent preferably comprises one or more of toluene, xylene, ethanol, acetone, ethyl acetate and water, and the present application does not have any special limitation on the ratio of the above-mentioned specific substances when the solvent is two or more of the above-mentioned specific choices, and the mixing can be carried out in any ratio.

[0049] In the present application, the mass ratio of the polymer matrix and the solvent is preferably 1:(5-20), more preferably 1:(8-16), and most preferably 1:(10-13).

[0050] ​In the present application, the first mixing is preferably carried out under the condition of stirring or ultrasonic, and the stirring mode is preferably mechanical stirring or magnetic stirring; the present application does not have any special limitation on the conditions of mechanical stirring, magnetic stirring and ultrasonic, and the conditions known to those skilled in the art can be used.

[0051] After obtaining the conductive dispersion liquid, the present application second mixes the conductive dispersion liquid and the micrometer-sized wave-transparent functional particles to obtain a film material dispersion liquid.

[0052] In the present application, the second mixing is preferably carried out under the condition of stirring or ultrasonic, and the stirring mode is preferably mechanical stirring or magnetic stirring; the present application does not have any special limitation on the conditions of mechanical stirring, magnetic stirring and ultrasonic, and the conditions known to those skilled in the art can be used.

[0053] After obtaining the film material dispersion liquid, the present application forms a film from the film material dispersion liquid to obtain the anti-icing film.

[0054] In the present application, the deposition mode is preferably spraying or dipping, and the present application does not have any special limitation on the process of spraying or dipping, and the process known to those skilled in the art can be used to ensure that the mesh wave-transparent pore of the micrometer-sized fiber bundle mesh does not block.

[0055] After the deposition is completed, the present application also preferably includes curing, and the present application does not have any special limitation on the process of curing, and the process known to those skilled in the art can be used.

[0056] The present application also provides the application of the electric heating anti-icing film in the windward surface of a radar cover or a stealth aircraft, which is prepared by the preparation method described in the above technical solution. The present application does not have any special limitation on the method of application, and the method known to those skilled in the art can be used.

[0057] The electric heating and wave-transparent integrated anti-icing film, the preparation method and the application thereof provided by the present application will be described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present application.

[0058] Example 1

[0059] A 100mm*100mm glass fiber-based composite material is selected as the substrate of the film material, and a 1mm-wide copper foil tape is pasted on both sides of the substrate as electrodes for the convenience of measuring resistance;

[0060] 1 g waterborne polyurethane, 0.25 g carbon nanotubes (outer diameter 10 nm, length 10 μm) and 10 g deionized water were mixed in a flask, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a conductive dispersion liquid was obtained;

[0061] 1 g polymethyl methacrylate microspheres (20 μm) and the conductive dispersion liquid were mixed, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a film material dispersion liquid was obtained;

[0062] The film material dispersion liquid was uniformly coated on the surface of a substrate with parallel electrodes by using a doctor blade, and was cured at room temperature for 6 h until complete curing to obtain the electric heating and wave-transparent integrated anti-icing film (thickness 150 μm);

[0063] The overall resistance (i.e. equivalent square resistance) of the electric heating anti-icing film was tested by using the resistance scale of a multimeter;

[0064] The test results were as follows: the square resistance of the electric heating and wave-transparent integrated anti-icing film was about 350 ohms, the calculated conductivity was 19 S / m, the average value of the S21 parameter in the frequency range of 0.3-18 GHz was -2.06 dB, and the minimum value was -2.07 dB, i.e. the wave transmission rate was about 62% (as shown in Figure 5 ). The heating power density of 20.8 kW / m 2 could be met under the application of 270 V DC current commonly used on an airplane, and the heating power density of 3.46 kW / m 2 could also be met under the application of 110 V DC current commonly used on an airplane.

[0065] Example 2

[0066] An aluminum alloy plate of 200 mm*50 mm was selected as the substrate of the film material, and a continuous PI film was completely pasted on the surface of the aluminum alloy to ensure insulation. A 1 mm wide copper foil tape was pasted on both sides of the substrate as electrodes for convenient resistance measurement;

[0067] 0.8 g silicone rubber, 0.24 g nano-graphite powder (particle size 20 nm) and 8 g dimethylbenzene were mixed in a flask, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a conductive dispersion liquid was obtained;

[0068] 1 g silica microspheres (50 μm) and the conductive dispersion liquid were mixed, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a film material dispersion liquid was obtained;

[0069] The film material dispersion is uniformly sprayed on the surface of the substrate with parallel electrodes by using a spray gun, and is cured at room temperature for 12 hours until complete curing to obtain the electric heating and wave-transparent integrated anti-icing film (100 μm thick); the overall resistance (i.e. equivalent sheet resistance) of the electric heating and wave-transparent integrated anti-icing film is tested by using the resistance scale of a multimeter;

[0070] The test result is that the sheet resistance of the electric heating and wave-transparent integrated anti-icing film is about 1200 ohms, the calculated conductivity is 8 S / m, at this time, the average value of S21 parameter in the frequency range of 0.3-18 GHz is -0.63 dB, and the minimum value is -0.633 dB, i.e. the wave permeability is about 86% (as shown in Figure 6 ). The heating power density of 24.3 kW / m 2 (or 4 kW / m 2 ) can be met under the condition of applying the commonly used 270 V (or 110 V) direct current on the aircraft.

[0071] Example 3

[0072] A 60 mm*60 mm glass plate is selected as the substrate of the film material, and a 1 mm wide copper foil tape is pasted on both sides of the substrate as electrodes for the convenience of measuring the resistance;

[0073] 0.3 g of epoxy resin, 0.03 g of carbon nanotubes (outer diameter 10 nm, length 10 μm) and 5 g of acetone are mixed in a flask, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a conductive dispersion is obtained;

[0074] 0.08 g of hollow glass microbeads (80 μm, bulk density 0.25 g / cm 3 ) and the conductive dispersion are mixed, and after magnetic mechanical stirring for 5 min and ultrasonic dispersion for 10 min, a film material dispersion is obtained;

[0075] After a rubber band is pasted around the periphery of the glass plate to form a pouring mold, the film material dispersion is poured into the surface of the substrate with parallel electrodes, and is cured at room temperature for 12 hours until complete curing, and after the rubber band around the periphery is removed, the electric heating and wave-transparent integrated anti-icing film (100 μm thick) is obtained; the overall resistance (i.e. equivalent sheet resistance) of the electric heating and wave-transparent integrated anti-icing film is tested by using the resistance scale of a multimeter;

[0076] The test result is that the sheet resistance of the electric heating and wave-transparent integrated anti-icing film is about 940 ohms, the calculated conductivity is 10.6 S / m, at this time, the average value of S21 parameter in the frequency range of 0.3-18 GHz is -1.21 dB, and the minimum value is -1.22 dB, i.e. the wave permeability is about 75.5% (as shown in Figure 7The heating power density of 21.5 kW / m2(or 3.6 kW / m2) can be satisfied in the case of applying the 270 V (or 110 V) DC power commonly used in the aircraft. 2 (or 3.6 kW / m 2 ) of the heating power density.

[0077] The above description is only preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An anti-icing and de-icing film integrating electric heating and wave transmission, characterized in that, It consists of a polymer matrix and nanoscale conductive functional particles and micron-scale wave-transmitting functional particles dispersed in the polymer matrix; The polymer matrix is ​​an electromagnetically transparent material; The micron-sized microwave-transparent functional particles self-assemble in the polymer matrix, and the self-assembly is in the form of a single-size homogeneous self-assembly formed by the self-assembly of micron-sized microwave-transparent functional particles of a single size. The micron-sized wave-transparent functional particles self-assemble to form micron-sized wave-transparent pores, which, after arranging the polymer matrix and nano-conductive functional particles, form a non-conductive region. The conductive nanoparticles have nanoscale pores, which are filled by a polymer matrix. The micron-sized and nano-sized porous channels form a micro-nano level electromagnetic wave-transmitting channel. The mass ratio of the polymer matrix, nanoscale conductive functional particles, and micron-scale wave-transparent functional particles is 1:(0.05~0.3):(0.1~1); The polymer matrix is ​​waterborne polyurethane or epoxy resin; The method for preparing the anti-icing film includes the following steps: The polymer matrix, nanoscale conductive functional particles and solvent are first mixed to obtain a conductive dispersion; The conductive dispersion and the micron-sized wave-transparent functional particles are mixed to obtain a membrane material dispersion. The membrane material dispersion is used to form a film to obtain the anti-icing film.

2. The anti-icing film as described in claim 1, characterized in that, The particle size of the nanoscale conductive functional particles is 1–100 nm.

3. The anti-icing film as described in claim 2, characterized in that, The nanoscale conductive functional particles include one or more of carbon materials, metallic materials, and intrinsically conductive polymer materials.

4. The anti-icing film as described in claim 1, characterized in that, The particle size of the micron-sized transparent functional particles is 1–50 μm.

5. The anti-icing film as described in claim 4, characterized in that, The materials of the micron-sized wave-transparent functional particles include inorganic non-conductive materials and / or organic non-conductive materials. The inorganic non-conductive material includes one or more of the following: silica microspheres, hollow glass microspheres, titanium dioxide microspheres, and glass fiber filaments. The organic non-conductive material includes one or more of polymethyl methacrylate microspheres, polystyrene microspheres, and polymer fiber filaments.

6. The method for preparing the anti-icing film according to any one of claims 1 to 5, characterized in that, Includes the following steps: The polymer matrix, nanoscale conductive functional particles and solvent are first mixed to obtain a conductive dispersion; The conductive dispersion and the micron-sized wave-transparent functional particles are mixed to obtain a membrane material dispersion. The membrane material dispersion is used to form a film to obtain the anti-icing film.

7. The preparation method according to claim 6, characterized in that, The solvent includes one or more of toluene, xylene, ethanol, acetone, ethyl acetate, and water; The mass ratio of the polymer matrix to the solvent is 1:(5-20).

8. The application of the electro-heated anti-icing film according to any one of claims 1 to 5 or the anti-icing film prepared by the preparation method according to claim 6 or 7 in the radome or the windward side of a stealth aircraft.

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