Flexible transparent porous gold electric heating film and preparation method thereof

Abstract

The application discloses a flexible transparent porous gold electric heating film and a preparation method thereof, and belongs to the technical field of electric heating films. The preparation method comprises the following steps: depositing a gold film on a substrate by adopting a magnetron sputtering method to prepare a gold / substrate composite film, vertically immersing the gold / substrate composite film into a polyurethane-poly(methyl methacrylate) solution, then taking the gold / substrate composite film out of the liquid surface, and then placing the gold / substrate composite film in a constant-temperature and constant-humidity box, and obtaining a porous polyurethane-poly(methyl methacrylate) template / gold / substrate composite film after drying; immersing the porous polyurethane-poly(methyl methacrylate) / gold / substrate composite film into an etching solution to perform selective etching, and preparing a porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film; and immersing the porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film into a template-removing solvent to remove the porous polyurethane-poly(methyl methacrylate) template layer, and obtaining the flexible transparent porous gold electric heating film.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric heating films, and particularly relates to a flexible transparent porous gold electric heating film and a preparation method thereof. BACKGROUND

[0002] With the wide application of flexible wearable electronic technology, flexible electric heaters are gradually replacing traditional rigid electric heaters and are applied to the fields of sensors, medical devices and artificial intelligence. Transparent film heaters are mainly applied to scenarios prone to fogging, such as camera view windows, automobile windows and transparent glass curtain walls, and play a role in defrosting, defogging and maintaining high light transmittance. However, in the traditional transparent film heater, the heat loss of the transparent electric heating film layer is large, and the defrosting and defogging efficiency needs to be further improved. The electric heating film, as the core component of the electric heater, plays an important role in the heating effect, safety, portability and comfort of the electric heater. The existing flexible electric heating film has intrinsic brittleness and rigidity, poor cutting precision and flexibility, and it is difficult to prepare a micro electric heater applied to a curved heat source surface.

[0003] Invention patent CN110944418A discloses a multi-layer flexible transparent electric heating film, which adopts the method of depositing a metal conductive layer and a metal oxide dielectric layer on a flexible substrate. Although this method takes into account the defogging performance and heating performance, the preparation method is complex and the transparency is low. Invention patent CN104883760B discloses a low-voltage transparent electric heating film, which adopts the method of directly sticking a graphene or carbon nanotube conductive layer on the film with UV glue. This method requires the setting of electrode bus bars, and the structure and process flow are relatively complex, and the cost is high. Therefore, it is urgent to develop a flexible transparent electric heating film material with high transparency, simple processing process, low cost, high stability and high safety. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a flexible transparent porous gold electric heating film and a preparation method thereof, which solves the problems in the prior art.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A preparation method of a flexible transparent porous gold electric heating film, comprising the following steps:

[0007] Depositing a gold film on a substrate by a magnetron sputtering method to prepare a gold / substrate composite film;

[0008] The gold / bottom composite film is vertically immersed in a polyurethane-poly(methyl methacrylate) solution, then the gold / bottom composite film is pulled out of the liquid surface, and then is placed in a constant temperature and humidity box, and after drying treatment, a porous polyurethane-poly(methyl methacrylate) template / gold / bottom composite film is obtained.

[0009] The porous polyurethane-poly(methyl methacrylate) / gold / bottom composite film is immersed in an etching solution for selective etching, and a porous polyurethane-poly(methyl methacrylate) template / porous gold / bottom composite film is prepared.

[0010] The porous polyurethane-poly(methyl methacrylate) template / porous gold / bottom composite film is immersed in a template removal solvent, and the porous polyurethane-poly(methyl methacrylate) template layer is removed, and a flexible transparent porous gold electric heating film is obtained.

[0011] Further, the bottom is any one of polyethylene terephthalate, polyimide, polypropylene and polydimethylsiloxane.

[0012] Further, the thickness of the gold film is 18-20 nm.

[0013] Further, the solvent used in the polyurethane-poly(methyl methacrylate) solution is tetrahydrofuran, and the solution concentration is 22-24 g / L.

[0014] Further, in the polyurethane-poly(methyl methacrylate) solution, the mass ratio of polyurethane to poly(methyl methacrylate) is 40:(5-7).

[0015] Further, the temperature in the constant temperature and humidity box is 20-30 DEG C, and the humidity is 85-95%.

[0016] Further, the etching solution is an iodine / potassium iodide etching solution; the concentration of the iodine / potassium iodide etching solution is 2-3 g / L, and the etching time is 2-5 min.

[0017] Further, the template solvent is acetone or N,N-dimethylformamide.

[0018] A flexible transparent porous gold electric heating film is prepared by using the preparation method of the flexible transparent porous gold electric heating film.

[0019] An electric heater comprises the flexible transparent porous gold electric heating film.

[0020] The present application has the following advantages:

[0021] The application improves the porosity and the number of through-holes of the porous polymer template by setting the optimized ratio of the polymer polyurethane and polymethyl methacrylate in the breath figure process, so as to prepare the porous gold electric heating film with the characteristics of high flexibility, high transparency, high electric heating performance, high stability and high safety, which has good application prospect in the field of flexible electronic devices. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 is a microscope image of the flexible transparent porous electric heating film prepared in Example 1;

[0024] Figure 2 is a temperature-time curve of the flexible transparent electric heating film in Example 1 under different applied voltages;

[0025] Figure 3 is the steady-state temperature of electric heating and the infrared thermal image of the flexible transparent electric heating film in Example 1 under different bending times. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0027] A preparation method of a flexible transparent porous gold electric heating film, comprising the following steps:

[0028] S1, depositing a gold film on a substrate by a magnetron sputtering method to prepare a gold / substrate composite film;

[0029] S2, vertically immersing the gold / substrate composite film into a polyurethane-polymethyl methacrylate solution, then pulling the gold / substrate composite film out of the liquid surface at a speed of 180 cm / min, and then placing it in a constant temperature and humidity box for 10 min, and then drying to obtain a porous polyurethane-polymethyl methacrylate template / gold / substrate composite film;

[0030] S3, immersing the porous polyurethane-poly(methyl methacrylate) / gold / substrate composite film into an iodine / potassium iodide etching solution to perform selective etching, to prepare a porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film;

[0031] S4, immersing the porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film into a template-removing solvent to remove the porous polyurethane-poly(methyl methacrylate) template layer, to obtain a flexible transparent porous gold / substrate electric heating film.

[0032] In S1, the substrate is any one of polyethylene terephthalate, polyimide, polypropylene and polydimethylsiloxane; the thickness of the gold film is 18-20 nm.

[0033] In S2, the solvent for the polyurethane-poly(methyl methacrylate) solution is tetrahydrofuran, and the solution concentration is 22-24 g / L; the mass ratio of polyurethane to poly(methyl methacrylate) is 40:(5-7).

[0034] In S2, the temperature in the constant-temperature and constant-humidity box is 20-30℃, and the humidity is 85-95%.

[0035] In S3, the concentration of the iodine / potassium iodide etching solution is 2-3 g / L; the mass ratio of iodine to potassium iodide is 1:1.3, and the etching time is 2-5 min.

[0036] In S4, the template solvent is acetone or N,N-dimethylformamide.

[0037] The technical solutions of the present application are specifically illustrated by the following examples and comparative examples, wherein the sources of the raw materials used in the examples and comparative examples are as follows:

[0038]

[0039] Example 1

[0040] A preparation method of a flexible transparent porous gold electric heating film, comprising the following steps:

[0041] S1, depositing a 20-nm gold film on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to prepare a gold / PET film.

[0042] S2, 0.4 g of polyurethane and 0.06 g of polymethyl methacrylate were dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-polymethyl methacrylate solution; the gold / PET film was vertically immersed in the polyurethane-polymethyl methacrylate solution, pulled out of the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 95%) for 10 min of standing, and after drying treatment, a porous polyurethane-polymethyl methacrylate template / gold / PET composite film was obtained;

[0043] S3, the porous polyurethane-polymethyl methacrylate template / gold / PET composite film was immersed in an iodine / potassium iodide etching solution with a concentration of 2.5 g / L for 3 min; the composite film was taken out and rinsed with deionized water to obtain a porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film.

[0044] S4, the porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film was immersed in a acetone solution for 5 min; the composite film was taken out, rinsed with deionized water and dried to obtain a porous gold / polyethylene terephthalate electric heating film.

[0045] Example 2

[0046] A method for preparing a flexible transparent porous gold electric heating film, comprising the following steps:

[0047] S1, a 18 nm gold film was deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0048] S2, 0.4 g of polyurethane and 0.06 g of polymethyl methacrylate were dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-polymethyl methacrylate solution; the gold / PET film was vertically immersed in the polyurethane-polymethyl methacrylate solution, pulled out of the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 95%) for 10 min of standing, and after drying treatment, a porous polyurethane-polymethyl methacrylate template / gold / PET composite film was obtained;

[0049] S3, the porous polyurethane-polymethyl methacrylate template / gold / PET composite film was immersed in an iodine / potassium iodide etching solution with a concentration of 2.5 g / L for 3 min; the composite film was taken out and rinsed with deionized water to obtain a porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film.

[0050] S4, the porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film is immersed in an acetone solution for 5 min; the composite film is taken out, washed with deionized water, and dried to obtain a porous gold / polyethylene terephthalate electric heating film.

[0051] Example 3

[0052] A method for preparing a flexible transparent porous gold electric heating film, comprising the following steps:

[0053] S1, a 20 nm gold film is deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0054] S2, 0.4 g of polyurethane and 0.05 g of poly (methyl methacrylate) are dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-poly (methyl methacrylate) solution; the gold / PET film is vertically immersed in the above polyurethane-poly (methyl methacrylate) solution, pulled out from the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 95%) for 10 min; after drying treatment, a porous polyurethane-poly (methyl methacrylate) template / gold / PET composite film is obtained.

[0055] S3, the porous polyurethane-poly (methyl methacrylate) template / gold / PET composite film is immersed in an iodine / potassium iodide etching solution with a concentration of 2.5 g / L for 3 min; the composite film is taken out and washed with deionized water to obtain a porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film.

[0056] S4, the porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film is immersed in an acetone solution for 5 min; the composite film is taken out, washed with deionized water, and dried to obtain a porous gold / polyethylene terephthalate electric heating film.

[0057] Example 4

[0058] A method for preparing a flexible transparent porous gold electric heating film, comprising the following steps:

[0059] S1, a 20 nm gold film is deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0060] S2, 0.4 g of polyurethane and 0.07 g of polymethyl methacrylate were dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-polymethyl methacrylate solution; the gold / PET film was vertically immersed in the polyurethane-polymethyl methacrylate solution, pulled out of the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 95%) for 10 min of standing, and after drying treatment, a porous polyurethane-polymethyl methacrylate template / gold / PET composite film was obtained;

[0061] S3, the porous polyurethane-polymethyl methacrylate template / gold / PET composite film was immersed in an iodine / potassium iodide etching solution with a concentration of 2.5 g / L for 3 min; the composite film was taken out and rinsed with deionized water to obtain a porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film.

[0062] S4, the porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film was immersed in a acetone solution for 5 min; the composite film was taken out, rinsed with deionized water and dried to obtain a porous gold / polyethylene terephthalate electro-heating film.

[0063] Example 5

[0064] A method for preparing a flexible transparent porous gold electro-heating film, comprising the following steps:

[0065] S1, a 20 nm gold film was deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0066] S2, 0.4 g of polyurethane and 0.06 g of polymethyl methacrylate were dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-polymethyl methacrylate solution; the gold / PET film was vertically immersed in the polyurethane-polymethyl methacrylate solution, pulled out of the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 85%) for 10 min of standing, and after drying treatment, a porous polyurethane-polymethyl methacrylate template / gold / PET composite film was obtained;

[0067] S3, the porous polyurethane-polymethyl methacrylate template / gold / PET composite film was immersed in an iodine / potassium iodide etching solution with a concentration of 2.5 g / L for 3 min; the composite film was taken out and rinsed with deionized water to obtain a porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film.

[0068] S4, the porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film is immersed in an acetone solution for 5 min; the composite film is taken out, washed with deionized water, and dried to obtain a porous gold / polyethylene terephthalate electric heating film.

[0069] Example 6

[0070] A method for preparing a flexible transparent porous gold electric heating film, comprising the following steps:

[0071] S1, a 20 nm gold film is deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0072] S2, 0.4 g of polyurethane and 0.06 g of poly (methyl methacrylate) are dissolved in 20 mL of tetrahydrofuran to obtain a polyurethane-poly (methyl methacrylate) solution; the gold / PET film is vertically immersed in the above polyurethane-poly (methyl methacrylate) solution, pulled out from the solution at a speed of 180 cm / min, and then placed in a constant temperature and humidity box (temperature 25℃, humidity 95%) for 10 min; after drying treatment, a porous polyurethane-poly (methyl methacrylate) template / gold / PET composite film is obtained.

[0073] S3, the porous polyurethane-poly (methyl methacrylate) template / gold / PET composite film is immersed in an iodine / potassium iodide etching solution with a concentration of 2 g / L for 5 min; the composite film is taken out and washed with deionized water to obtain a porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film.

[0074] S4, the porous polyurethane-poly (methyl methacrylate) template / porous gold / PET composite film is immersed in an acetone solution for 5 min; the composite film is taken out, washed with deionized water, and dried to obtain a porous gold / polyethylene terephthalate electric heating film.

[0075] Example 7

[0076] A method for preparing a flexible transparent porous gold electric heating film, comprising the following steps:

[0077] S1, a 20 nm gold film is deposited on a polyethylene terephthalate (PET) transparent substrate by magnetron sputtering to obtain a gold / PET film.

[0078] S2, dissolve 0.4 g of polyurethane and 0.06 g of polymethyl methacrylate in 20 mL of tetrahydrofuran to obtain a polyurethane-polymethyl methacrylate solution; vertically immerse the gold / PET film in the polyurethane-polymethyl methacrylate solution, pull it out of the solution at a speed of 180 cm / min, and then place it in a constant temperature and humidity chamber (temperature 25℃, humidity 95%) for 10 min, and then obtain a porous polyurethane-polymethyl methacrylate template / gold / PET composite film after drying treatment;

[0079] S3, immerse the porous polyurethane-polymethyl methacrylate template / gold / PET composite film in an iodine / potassium iodide aqueous solution with a concentration of 3 g / L for 2 min; then take out the composite film and rinse it with deionized water to obtain a porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film.

[0080] S4, immerse the porous polyurethane-polymethyl methacrylate template / porous gold / PET composite film in an acetone solution for 5 min; then take out the composite film, rinse it with deionized water, and dry it to obtain a porous gold / polyethylene terephthalate electroheating film.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1 is only that in S1, a 25 nm gold film is deposited on the polyethylene terephthalate transparent substrate by a magnetron sputtering method.

[0083] Comparative Example 2

[0084] The difference between Comparative Example 2 and Example 1 is only that in S1, a 15 nm gold film is deposited on the polyethylene terephthalate transparent substrate by a magnetron sputtering method.

[0085] Comparative Example 3

[0086] The difference between Comparative Example 3 and Example 1 is only that in S2, the temperature in the constant temperature and humidity chamber is 25℃ and the humidity is 60%.

[0087] Comparative Example 4

[0088] The difference between Comparative Example 4 and Example 1 is only that in S2, the process of not placing the sample in the constant temperature and humidity chamber is removed.

[0089] Comparative Example 5

[0090] The difference between Comparative Example 4 and Example 1 is only that in S2, the polymer solution does not use polymethyl methacrylate, but only uses polyurethane.

[0091] Experimental Test

[0092] The sheet resistance and transmittance of the prepared electrically heated films were tested using a four-probe sheet resistance meter and a UV-Vis spectrophotometer for the porous gold / PET films prepared in Examples 1-7 and Comparative Examples 1-5.

[0093] The prepared porous gold / PET film was cut into 40mm × 30mm samples, and copper foil conductive adhesive was used to connect the two ends of the samples as electrodes to obtain a single-layer electrothermal device. A voltage of 6V was applied to the electrodes at both ends of the porous gold / PET film, and the electrothermal temperature and response time were tested using an infrared thermal imager. The electrothermal device was cyclically bent at a bending angle of 90° to obtain the bending resistance performance of the device. If the electrothermal performance of the device significantly decreased after a certain number of bends, the device was considered to have reached its maximum bending resistance performance. The sheet resistance, transmittance, electrothermal temperature, response time, and bending resistance of the porous gold / PET film are shown in Table 1.

[0094] Table 1 Performance Tests

[0095]

[0096] like Figure 1 As shown in Table 1, the sample prepared in Example 1 has a uniform microporous structure. It exhibits high conductivity, high transparency, and high flexibility, with a sheet resistance of 1.41 Ω / sq and a transmittance of 87%. Figure 2 As shown in Table 1, the electric heating device has an electric heating temperature of 103.9℃ and a response time of 4s at a working voltage of 6V; Figure 3 As shown in Table 1, the bending resistance can reach 10,000 cycles.

[0097] Based on the test data in Table 1, comparing the samples of Example 1 and Comparative Example 1, the use of a thick gold film in Comparative Example 1 makes it difficult to form a porous gold structure with perforated holes during etching. Therefore, the porous gold film sample has lower transparency and poorer bending resistance. Comparing the samples of Example 1 and Comparative Example 2, the use of a thin gold film in Comparative Example 2 makes it easier for large areas of the gold film to detach during etching, forming discontinuous structures. This damages the grid conductive structure of the porous gold film, resulting in a reduced number of porous gold structures after etching. Consequently, the sheet resistance of the sample is significantly increased, the electrothermal temperature is significantly reduced, and the response time is significantly improved. For the sample of Comparative Example 4, because it is not placed in a constant temperature and humidity chamber, it is difficult to form a porous polyurethane-polymethyl methacrylate template film with many perforated holes. Therefore, the porous gold film sample after etching has even lower transparency and poorer bending resistance. Compared with the samples of Example 1 and Comparative Example 5, Comparative Example 5 uses only polyurethane polymer, which makes it difficult to obtain a porous template layer with a perforated structure over a large area, that is, it is difficult to obtain a porous gold film. Therefore, its sample has lower transparency and poorer bending resistance.

[0098] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

[0099] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method for preparing a flexible transparent porous gold electric heating film, characterized in that, The method comprises the following steps: depositing a gold film on a substrate by a magnetron sputtering method to prepare a gold / substrate composite film; immersing the gold / substrate composite film vertically into a polyurethane-poly(methyl methacrylate) solution, then pulling the gold / substrate composite film out of the liquid surface, and then placing the gold / substrate composite film in a constant temperature and humidity box, and obtaining a porous polyurethane-poly(methyl methacrylate) template / gold / substrate composite film after drying treatment; immersing the porous polyurethane-poly(methyl methacrylate) / gold / substrate composite film into an etching solution for selective etching to prepare a porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film; immersing the porous polyurethane-poly(methyl methacrylate) template / porous gold / substrate composite film into a template removal solvent to remove the porous polyurethane-poly(methyl methacrylate) template layer, and obtaining a flexible transparent porous gold electric heating film; the solvent used in the polyurethane-poly(methyl methacrylate) solution is tetrahydrofuran, and the solution concentration is 22-24 g / L; in the polyurethane-poly(methyl methacrylate) solution, the mass ratio of polyurethane to poly(methyl methacrylate) is 40: (5-7).

2. The method of claim 1, wherein the flexible transparent porous gold heating film is prepared by the steps of: (a) preparing a gold film on a substrate; (b) forming a porous structure on the gold film; and (c) forming a transparent protective layer on the porous structure. the substrate is any one of polyethylene terephthalate, polyimide, polypropylene and polydimethylsiloxane.

3. The method of claim 1, wherein the flexible transparent porous gold heating film is prepared by the steps of: (a) preparing a gold film on a substrate; (b) forming a porous structure on the gold film; and (c) forming a transparent protective layer on the porous structure. the thickness of the gold film is 18-20 nm.

4. The method of claim 1, wherein the flexible transparent porous gold heating film is prepared by the steps of: (a) preparing a gold film on a substrate; (b) forming a porous structure on the gold film; (c) forming a transparent protective layer on the porous structure; and (d) removing the substrate. the temperature in the constant temperature and humidity box is 20-30 ℃, and the humidity is 85-95%.

5. The method of claim 1, wherein the flexible transparent porous gold heating film is prepared by the steps of: (a) preparing a gold film on a substrate; (b) forming a porous structure on the gold film; (c) forming a transparent protective layer on the porous structure; and (d) removing the substrate. the etching solution is an iodine / potassium iodide etching solution; the concentration of the iodine / potassium iodide etching solution is 2-3 g / L, and the etching time is 2-5 min.

6. The method of claim 1, wherein the flexible transparent porous gold heating film is prepared by the steps of: (a) preparing a gold film on a substrate; (b) forming a porous structure on the gold film; (c) forming a transparent protective layer on the porous structure; and (d) removing the substrate. the template solvent is acetone or N,N-dimethylformamide.

7. A flexible transparent porous gold electric heating film, characterized in that, The flexible transparent porous gold electric heating film is prepared by the method of any one of claims 1-6.

8. An electric heater, characterized by The flexible transparent porous gold electric heating film is prepared by the method of any one of claims 1-6.

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