Electric heating layer with PTC (Positive Temperature Coefficient) effect as well as preparation method and application of electric heating layer

Abstract

The invention provides an electric heating layer with a PTC (Positive Temperature Coefficient) effect as well as a preparation method and application thereof, the electric heating layer comprises an electric heating material, and the electric heating material comprises a conductive component, a substance containing hydroxyl and / or carboxyl and a filler with the PTC effect; wherein the filler with the PTC effect is deposited on the surface of the conductive component, and is connected with the conductive component through a substance containing hydroxyl and / or carboxyl. The electric heating layer has the characteristics of self-limiting temperature and overheating protection, and can realize the reduction of heating power and the reduction of heating temperature to achieve the self-limiting temperature effect and prevent extra safety risks caused by over-high temperature through the step increase of resistance value under the condition of over-high heating temperature.

Description

Technical Field

[0001] This invention belongs to the field of electrothermal film technology, specifically relating to an electrothermal layer with PTC effect, its preparation method, and its applications. Background Technology

[0002] Wind power generation refers to converting the kinetic energy of wind into electrical energy. Wind energy is a clean and pollution-free renewable energy source. A wind turbine is a device that converts wind energy into mechanical work, which drives a rotor to rotate and ultimately outputs alternating current (AC) electricity. A wind turbine generally consists of components such as wind turbine blades, a generator, a deflector, a tower, a speed limiting safety mechanism, and an energy storage device.

[0003] The working principle of a wind turbine is relatively simple. The turbine blades rotate under the influence of wind, converting the kinetic energy of the wind into the mechanical energy of the turbine shaft. The generator then rotates under the drive of the turbine shaft to generate electricity. The turbine blades are one of the most important driving mechanisms in a wind turbine. The structure and stability of the turbine blades during operation have a significant impact on the overall efficiency of the wind turbine. In extremely cold climates, because the turbine blades cannot maintain high-speed rotation for extended periods, their surfaces easily freeze, altering their operating state and severely affecting the overall efficiency and stability of the wind turbine. Therefore, quickly removing ice from the turbine blades is a primary challenge for wind turbines used in frigid environments.

[0004] Traditional methods include surface de-icing via vibration or manual methods. These methods require manual monitoring and control, are difficult to detect and implement promptly, are costly, and have limited applicability. Electrothermal de-icing utilizes the electrothermal effect of conductive materials to heat the blade surface above freezing, achieving de-icing. This is currently the most effective de-icing method. However, during electrothermal de-icing, excessively high temperatures can lead to mechanical failure of the wind turbine blades, resulting in significant economic losses. Summary of the Invention

[0005] Based on the problems existing in the prior art, the present invention provides an electrothermal layer, its preparation method and application. The electrothermal layer has the characteristics of flexibility and overheat protection. When the heating temperature is too high, it can reduce the heating power by step increasing the resistance value, thereby reducing the heating temperature, preventing mechanical failure of the wind turbine blades, and achieving the purpose of overheat protection.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] An electrothermal layer comprising an electrothermal material, the electrothermal material comprising a conductive component, a substance containing hydroxyl and / or carboxyl groups, and a filler having a PTC effect; wherein the filler having a PTC effect is deposited on the surface of the conductive component and is connected to the conductive component through the substance containing hydroxyl and / or carboxyl groups.

[0008] In this invention, the PTC effect, or Positive Temperature Coefficient effect, refers to the property that the resistance of a material exhibits a step-like increase with rising material temperature. That is, within a certain temperature range, the higher the temperature, the greater the resistance. Research has found that this characteristic can be utilized to apply materials with the PTC effect to the electrothermal film on the surface of wind turbine blades. When the heating power of the electrothermal material is too high, leading to excessively high temperatures, the resistance can spontaneously increase, thereby reducing the heating power and achieving overheat protection to prevent blade damage.

[0009] According to an embodiment of the present invention, the filler with the PTC effect is a hydroxylated filler with the PTC effect. Specifically, it is further modified by a silane coupling agent. The filler with the PTC effect can be connected to the conductive component via chemical and / or physical interactions through substances containing hydroxyl and / or carboxyl groups.

[0010] According to an embodiment of the present invention, the filler having the PTC effect is deposited on part or all of the surface of the conductive component and is connected to the conductive component by a substance containing hydroxyl and / or carboxyl groups.

[0011] According to embodiments of the present invention, the substance containing hydroxyl and / or carboxyl groups is modified onto part or all of the surface of the conductive component through π-π interactions.

[0012] According to embodiments of the present invention, the conductive material includes, but is not limited to, one or more of carbon fibers, carbon nanotubes, etc. Carbon fibers and carbon nanotubes prepared by methods known in the art are both suitable for the solutions of the present invention.

[0013] According to an embodiment of the present invention, the filler with the PTC effect is selected from Ba. x M (2-2x) / n TiO3 is a material in which M is a dopant element, including but not limited to Sr. 2+ Ca 2+ Cd 2+ Cu 2+ Ni 2+ Zr 4+ Sn 4+ Hf 4+ One or more of the following, where x is the mole fraction of Ba (0-1) and n is the valence of the dopant element M.

[0014] For example, the filler with the PTC effect is selected from BaTiO3, Ba 0.85 Sr 0.15 TiO3, Ba 0.7 Sr 0.15 La 0.1 TiO3 or Ba 0.6 Ca 0.1 Sn 0.15 TiO3 substances.

[0015] According to embodiments of the present invention, the substance containing hydroxyl and / or carboxyl groups is selected from at least one of graphene oxide, graphynylene oxide, and fused-ring aromatic hydrocarbons containing hydroxyl and / or carboxyl groups.

[0016] According to an embodiment of the present invention, the number of graphene oxide layers is 1 to 10.

[0017] According to an embodiment of the present invention, the particle size range of the filler with PTC effect is 1nm-1μm, for example, 1nm, 2nm, 5nm, 10nm, 20nm, 30nm, 50nm, 80nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm or 1μm.

[0018] According to embodiments of the present invention, the mass of the substance containing hydroxyl and / or carboxyl groups accounts for 0.01 to 1 wt% of the total mass of the heating layer, for example, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.12 wt%, 0.15 wt%, 0.18 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or 1 wt%.

[0019] According to an embodiment of the present invention, the mass of the filler having the PTC effect accounts for 0.01 to 50 wt% of the total mass of the electrothermal layer, for example, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.12 wt%, 0.15 wt%, 0.18 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 35 wt%, 38 wt%, 40 wt%, 45 wt%, or 50 wt%.

[0020] According to an embodiment of the present invention, the mass of the conductive material accounts for 49-99.98 wt% of the total mass of the electrothermal layer, for example, 49 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, 98 wt%, 99 wt%, 99.9 wt%, or 99.98 wt%.

[0021] According to an embodiment of the present invention, the thickness of the heating layer is not particularly limited and can be reasonably selected based on actual usage. For example, the thickness of the heating layer is 2μm to 2000μm.

[0022] According to an embodiment of the present invention, the electrothermal layer comprises a fabric woven from the electrothermal material, or a film layer formed by coating a slurry comprising the electrothermal material.

[0023] Research has found that in the electrothermal layer of this invention, Ba exhibits a PTC effect. x M (2-2x) / n TiO3 particles are deposited on the surface of conductive carbon fibers or carbon nanotubes. When they form a macroscopic electrothermal layer material, Ba... x M (2-2x) / n TiO3 particles exist within the conductive carbon fibers or carbon nanotubes as an interfacial layer. When the temperature of the electrothermal layer material is too high, reaching Ba... x M (2-2x) / n At the Curie temperature, the resistance of TiO3 particles increases dramatically, which in turn increases the overall resistance of the heating layer material, thereby reducing the heating power and lowering the heating temperature to achieve self-limiting temperature and overheat protection.

[0024] The present invention also provides a method for preparing the above-mentioned electrothermal layer, the method comprising the following steps:

[0025] 1) A conductive material is mixed with a substance containing hydroxyl and / or carboxyl groups to obtain a conductive material with a surface bonded to a substance containing hydroxyl and / or carboxyl groups.

[0026] 2) Mix the filler with PTC effect and optional additives or no dispersant to obtain a mixed system;

[0027] 3) The conductive material with hydroxyl and / or carboxyl groups attached to its surface in step 1) is mixed with the mixture system in step 2) to prepare an electrothermal material.

[0028] According to an embodiment of the present invention, step 2) specifically comprises:

[0029] a) A hydroxylated modified filler is prepared by mixing a filler with a PTC effect and hydrogen peroxide;

[0030] b) Mix the silane coupling agent and the hydroxylated modified filler from step a), react, and prepare the silane coupling agent modified filler.

[0031] c) Mix the silane coupling agent modified filler from step b) with optional additives or no dispersant to obtain a mixed system.

[0032] According to an embodiment of the present invention, the method further includes the following steps:

[0033] 4) The electrothermal material from step 3) is used to make an electrothermal layer.

[0034] According to an embodiment of the present invention, in step 1), the definition of the conductive material is as described above.

[0035] According to an embodiment of the present invention, in step 1), the mass ratio of the conductive material to the substance containing hydroxyl and / or carboxyl groups is 100:(0.01 to 1), for example, 100:0.01, 100:0.02, 100:0.05, 100:0.08, 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, or 100:1.

[0036] According to an embodiment of the present invention, in step 1), the conductive material is mixed with a dispersion of a substance containing hydroxyl and / or carboxyl groups (preferably an aqueous dispersion of a substance containing hydroxyl and / or carboxyl groups). The concentration of the dispersion of the substance containing hydroxyl and / or carboxyl groups is 0.05–0.5 g / L, exemplarily 0.05 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, or 0.5 g / L.

[0037] According to an embodiment of the present invention, in step 1), the mixing temperature is room temperature and the mixing time is 5 to 20 minutes.

[0038] According to an embodiment of the present invention, in step 1), the mixing is performed under ultrasonic conditions.

[0039] According to an embodiment of the present invention, in step 1), during the mixing process, substances containing hydroxyl and / or carboxyl groups are modified onto part or all of the surface of the conductive component through π-π interactions.

[0040] According to an embodiment of the present invention, in steps 2) and a), the definition of the packing material having the PTC effect is as described above.

[0041] According to an embodiment of the present invention, in step a), the concentration of hydrogen peroxide is 25-30%.

[0042] According to an embodiment of the present invention, in step a), the mixing temperature is 80-95°C and the mixing time is 4-10 hours.

[0043] According to an embodiment of the present invention, step a) further includes washing and drying the prepared hydroxylated modified filler; for example, washing with deionized water and vacuum drying at 80-90°C for 10-15 hours.

[0044] According to an embodiment of the present invention, in step b), the mass ratio of silane coupling agent to hydroxylated modified filler is 0.2 to 2:1, for example, 0.2:1, 0.3:1, 0.5:1, 0.8:1, 0.9:1, 1:1, 1.2:1, 1.3:1, 1.5:1, 1.8:1, or 2:1.

[0045] According to an embodiment of the present invention, in step b), the reaction temperature is 60–150°C and the reaction time is 1–48 hours.

[0046] According to an embodiment of the present invention, in step b), the reaction is carried out in the presence of an organic solvent.

[0047] According to an embodiment of the present invention, in step b), the organic solvent is selected from at least one of toluene, xylene, petroleum ether, ethanol, tetrahydrofuran, N,N-dimethylformamide, dichloromethane, chloroform, pyridine, and acetonitrile.

[0048] According to an embodiment of the present invention, in step b), the silane coupling agent is selected from γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, 1,2-bis(triethoxysilyl)ethane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, phenylaminomethyltriethoxysilane, and phenylaminomethyltrimethoxysilane.

[0049] According to an embodiment of the present invention, step b) further includes washing and drying the prepared silane coupling agent modified filler; for example, washing with ethanol and vacuum drying at 80-90°C for 10-15 hours.

[0050] According to an embodiment of the present invention, in steps 2) and c), the dispersant is selected from at least one of commercially available inorganic particle dispersants, including but not limited to at least one of polyvinylpyrrolidone, polyethylene glycol, sodium alginate, and sodium polystyrene sulfonate.

[0051] According to an embodiment of the present invention, in steps 2) and c), the mass ratio of the filler to the dispersant is 100:(0-5), such as 100:(0.5-1.5), for example 100:0.5, 100:0.6, 100:0.8, 100:1, 100:1.2 or 100:1.5.

[0052] According to an embodiment of the present invention, in steps 2) and c), the concentration of the filler in the mixed system is 5 to 15 g / L, for example, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L or 15 g / L.

[0053] According to an embodiment of the present invention, in steps 2) and c), the mixed system is a system formed by mixing filler and dispersant with deionized water.

[0054] According to an embodiment of the present invention, in steps 2) and c), in order to further obtain a uniformly dispersed mixed system, it is preferable to subject the mixed system to ultrasonic dispersion treatment for 30 minutes or more.

[0055] According to an embodiment of the present invention, in step 3), the mixing temperature is room temperature and the mixing time is 5 to 20 minutes.

[0056] According to an embodiment of the present invention, in step 3), during the mixing process, the silane coupling agent modified filler reacts with substances containing hydroxyl and / or carboxyl groups to form chemical or physical bonds, thereby achieving the deposition of filler with PTC effect on part or all of the surface of the conductive component.

[0057] According to an embodiment of the present invention, in step 4), the electrothermal material is woven into a fabric such as a woven fabric, textile, or non-woven fabric to obtain the electrothermal layer. For example, the electrothermal material is woven into a woven fabric using a warp and weft weaving method.

[0058] According to an embodiment of the present invention, in step 4), the slurry including the electrothermal material is coated (e.g., sprayed, brushed) or filtered to form an electrothermal layer.

[0059] The present invention also provides an electrothermal layer, which is prepared by the above method.

[0060] The present invention also provides the use of the above-described electrothermal layer in the field of anti-icing / de-icing.

[0061] According to an embodiment of the present invention, it is used for anti-icing / de-icing of wind turbine blade surfaces.

[0062] The beneficial effects of this invention are:

[0063] This invention provides an electrothermal layer with PTC effect, its preparation method and application. The electrothermal layer has the characteristics of self-limiting temperature and overheat protection. When the heating temperature is too high, it can reduce the heating power by step increasing the resistance value, thereby reducing the heating temperature and achieving a self-limiting temperature effect, preventing the additional safety risks caused by excessive temperature. Attached Figure Description

[0064] Figure 1 The temperature resistance characteristic curve of the electrothermal layer prepared in Example 1 is shown.

[0065] Figure 2 The resistance-temperature characteristic curve of the electrothermal layer prepared in Comparative Example 1 is shown. Detailed Implementation

[0066] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0067] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0068] Example 1

[0069] (1) γ-aminopropyltriethoxysilane modified barium titanate nanoparticles

[0070] Barium titanate nanoparticles (BT) were placed in a 30% H2O2 solution and stirred at 90°C for 6 hours. After repeated filtration and washing with deionized water, the nanoparticles were dried in a vacuum oven at 80°C for 12 hours to obtain hydroxylated barium titanate nanoparticles (BT-OH).

[0071] 10g of the modified barium titanate nanoparticles were placed in 200ml of anhydrous toluene, and 10g of γ-aminopropyltriethoxysilane (APTES) was added. The mixture was refluxed at 120℃ for 24h. After filtration, the nanoparticles were washed three times with ethanol and dried in a vacuum oven at 80℃ for 12h to obtain APTES-modified barium titanate nanoparticles (BT-APTES).

[0072] (2) BT nanoparticles loaded on carbon fiber surface

[0073] BT-APTES and polyvinylpyrrolidone (PVP) were added to deionized water and ultrasonically dispersed for 30 min to obtain BT-APTES dispersions with concentrations of 10 g / L and 0.1 g / L, respectively.

[0074] A carbon fiber bundle with a yarn type of 12k was immersed in a GrO / H2O dispersion with a concentration of 0.1 g / L, ultrasonically treated for 10 minutes, removed and then immersed in the above BT-APTES dispersion. After winding, a carbon fiber bundle with PTC effect and GrO and BT deposited on the surface was obtained.

[0075] (3) Carbon fiber fabrics with PTC effect

[0076] Carbon fiber bundles exhibiting the PTC effect were uniformly and parallelly arranged into one layer each at angles of +45° and -45°, with each layer having a basis weight of 200 g / m. 2 Then, they are woven together by warp knitting yarn to obtain a weight of 400g / m². 2 It is a ±45° biaxial warp-knitted carbon fiber fabric with PTC effect.

[0077] Comparative Example 1

[0078] A carbon fiber bundle with a yarn type of 12k was immersed in a GrO / H2O dispersion with a concentration of 0.1 g / L, ultrasonically treated for 10 minutes, and then taken out and wound to obtain a carbon fiber bundle (CF-GrO) with GrO deposited on the surface.

[0079] CF-GrO carbon fiber bundles were evenly and parallelly arranged into one layer each at angles of +45° and -45°, with each layer having a basis weight of 200 g / m.2 Then, they are woven together by warp knitting yarn to obtain a weight of 400g / m². 2 And ±45° biaxial warp-knitted carbon fiber cloth.

[0080] Example 2

[0081] (1) γ-aminopropyltrimethoxysilane modified barium titanate nanoparticles

[0082] Barium titanate nanoparticles (BT) were placed in a 30% H2O2 solution and stirred at 80°C for 10 h. After repeated filtration and washing with deionized water, they were dried in a vacuum oven at 90°C for 10 h to obtain hydroxylated barium titanate nanoparticles (BT-OH).

[0083] 10g of the modified barium titanate nanoparticles were placed in 200ml of anhydrous toluene, and 12g of γ-aminopropyltrimethoxysilane (KH540) was added. The mixture was refluxed at 120℃ for 24h. After filtration, the nanoparticles were washed three times with ethanol and dried in a vacuum oven at 90℃ for 10h to obtain KH540 modified barium titanate nanoparticles (BT-KH540).

[0084] (2) BT nanoparticles loaded on carbon nanotube surface

[0085] Add BT-KH540 to deionized water and sonicate for 30 minutes to obtain 100 ml of BT-KH540 dispersion with a concentration of 1 g / L.

[0086] 2g of carbon nanotubes (CNTs) were dispersed in 100ml of GrO / H2O dispersion with a concentration of 0.01g / L, and ultrasonic treatment was performed for 30 minutes to obtain a carbon nanotube (CNT-GrO) dispersion with GrO sheets on the surface.

[0087] (3) Carbon nanotube paper CNT-BT with PTC effect

[0088] The CNT-GrO dispersion was mixed with the BT-KH540 dispersion, stirred for 30 min, and then filtered. The resulting filter cake was dried in a vacuum oven at 80℃ for 12 h to obtain carbon nanotube paper CNT-BT with PTC effect.

[0089] Figure 1 The temperature resistance characteristic curve of the electrothermal layer prepared in Example 1 is shown. Figure 2 The resistance-temperature characteristic curve of the electrothermal layer prepared in Comparative Example 1 is shown.

[0090] from Figure 1 and Figure 2As can be seen, the electrothermal layer prepared by this invention exhibits a significant PTC effect. When this electrothermal layer is applied to wind turbine blades, the surface temperature of the blades continuously increases with the increasing current. However, when the temperature exceeds 60°C, the resistance of the electrothermal layer increases in a stepwise manner, causing the surface temperature of the blades to decrease. This reduces the heating power, lowers the heating temperature, and achieves self-limiting temperature control and overheat protection. It effectively removes ice from the surface of the wind turbine blades without damaging them due to the generated high temperatures.

[0091] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrothermal layer, the electrothermal layer comprising an electrothermal material, the electrothermal material comprising a conductive component, a substance containing hydroxyl and / or carboxyl groups, and a filler having a PTC effect; wherein, The filler with PTC effect is deposited on the surface of the conductive component and connected to the conductive component by a substance containing hydroxyl and / or carboxyl groups.

2. The electrothermal layer according to claim 1, wherein, The conductive material includes one or more of carbon fiber and carbon nanotubes; And / or, the filler with the PTC effect is selected from those with the chemical formula Ba. x M (2-2x) / n TiO3 is a material in which M is a dopant element, including but not limited to Sr. 2+ Ca 2+ Cd 2+ Cu 2+ Ni 2+ Zr 4+ Sn 4+ Hf 4+ One or more of the following, where x is the mole fraction of Ba, ranging from 0 to 1, and n is the valence of the dopant element M; And / or, the substance containing hydroxyl and / or carboxyl groups is selected from at least one of graphene oxide, graphynylene oxide, and fused-ring aromatic hydrocarbons.

3. The electrothermal layer according to claim 1 or 2, wherein, The particle size distribution of the filler with PTC effect is 1 nm-1 μm.

4. The electrothermal layer according to any one of claims 1-3, wherein, The mass of the substance containing hydroxyl and / or carboxyl groups accounts for 0.01 to 1 wt% of the total mass of the heating layer; And / or, the mass of the filler with the PTC effect accounts for 0.01 to 50 wt% of the total mass of the electrothermal layer; And / or, the mass of the conductive material accounts for 49-99.98 wt% of the total mass of the electrothermal layer.

5. The electrothermal layer according to any one of claims 1-4, wherein, The electrothermal layer comprises a fabric woven from the electrothermal material, or a film layer formed by coating a slurry comprising the electrothermal material.

6. A method for preparing the electrothermal layer according to any one of claims 1-5, the method comprising the following steps: 1) A conductive material is mixed with a substance containing hydroxyl and / or carboxyl groups to obtain a conductive material with a surface bonded to a substance containing hydroxyl and / or carboxyl groups. 2) Mix the filler with PTC effect and optional additives or no dispersant to obtain a mixed system; 3) The conductive material with hydroxyl and / or carboxyl groups attached to its surface in step 1) is mixed with the mixture system in step 2) to prepare an electrothermal material.

7. The preparation method according to claim 6, wherein, Step 2) specifically involves: a) A hydroxylated modified filler is prepared by mixing a filler with a PTC effect and hydrogen peroxide; b) Mix the silane coupling agent and the hydroxylated modified filler from step a), react, and prepare the silane coupling agent modified filler. c) Mix the silane coupling agent modified filler from step b) with optional additives or no dispersant to obtain a mixed system; Preferably, the method further includes the following steps: 4) The electrothermal material from step 3) is used to make an electrothermal layer.

8. The preparation method according to claim 7, wherein, In step a), the mixing temperature is 80–95°C, and the mixing time is 4–10 hours; And / or, in step b), the mass ratio of silane coupling agent to hydroxylated modified filler is 0.2 to 2:1; the reaction temperature is 60 to 150°C; and the reaction time is 1 to 48 hours. And / or, in step 1), the mass ratio of the conductive material to the substance containing hydroxyl and / or carboxyl groups is 100:(0.01-1); the mixing temperature is room temperature, and the mixing time is 5-20 min; And / or, in steps 2) and c), the dispersant includes at least one of polyvinylpyrrolidone, polyethylene glycol, sodium alginate, and sodium polystyrene sulfonate; And / or, in steps 2) and c), the mass ratio of the filler to the dispersant is 100:0 to 5.

9. The preparation method according to claim 7, wherein, In step 4), the electrothermal material is woven into a woven fabric, textile, or nonwoven fabric to obtain an electrothermal layer; or, the slurry containing the electrothermal material is coated or filtered to form an electrothermal layer.

10. Use of the electrothermal layer according to any one of claims 1-5, for use in the field of anti-icing / de-icing.

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