Preparation method of high-stability silver nanowire and method for preparing flexible transparent electrode by adopting silver nanowire

Abstract

The embodiment of the invention discloses a preparation method of a high-stability nano silver wire and a method for preparing a flexible transparent electrode by adopting the nano silver wire, by preparing sulfydryl modified PVP (Polyvinyl Pyrrolidone), sulfydryl can provide hydrogen atoms to neutralize free radicals generated in an oxidation process to form stable disulphide, further oxidative damage caused by the free radicals is prevented, and the stability of the flexible transparent electrode is improved. The sulfydryl modified PVP is used for preparing the silver nanowire, so that the oxidation resistance of the prepared silver nanowire is improved; according to the flexible transparent electrode, the silver nanowires are dispersed in an ethanol solution, then the ethanol solution is sprayed on a PET film, and drying is carried out to prepare the flexible transparent electrode. According to the technical scheme, the method has the advantages of being easy to operate, high in controllability, suitable for large-scale production and the like, can be widely applied to preparation of the silver nanowire with excellent stability, conductivity and optical performance, and can be used for preparing a flexible transparent electrode by coating a flexible substrate with the silver nanowire.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of transparent electrodes, and in particular to a method for preparing a high-stability nano silver wire and a method for preparing a flexible transparent electrode using the nano silver wire. Background Art

[0002] In recent years, with the rapid development of flexible electronic technology, the demand for high-performance transparent electrodes has been growing. Traditional transparent electrode materials, such as indium tin oxide (ITO), have problems such as high cost, high brittleness, and difficulty in preparing large-area devices, which limit their application scope. Therefore, exploring new transparent electrode materials has become a hot topic in current research. Silver nanowires, as a new type of transparent electrode material, have high conductivity, high transmittance and good flexibility, and show great potential in the field of flexible electronic devices. Silver nanowires can effectively replace ITO and be used to manufacture a variety of electronic devices such as flexible displays, touch screens, solar cells, etc.

[0003] Silver nanowires (AgNWs) are nanoscale linear materials made of silver that have attracted much attention for their excellent electrical conductivity and optical transparency. Silver nanowires are usually composed of silver filaments with diameters ranging from tens to hundreds of nanometers and lengths of up to several microns. This high aspect ratio structure allows silver nanowires to have good optical transparency while maintaining excellent electrical conductivity. Silver nanowires are generally prepared by chemical reduction methods, such as using a polyol method to reduce silver salts to nanowire form under specific conditions. This method is relatively simple and highly controllable. Silver nanowires have a very high surface area to volume ratio, which means that they have a larger contact area with the surrounding environment and are more susceptible to oxidation reactions. Silver itself is relatively stable on a macroscopic scale, but at the nanoscale, due to the high proportion of surface atoms, it has high surface energy and increased chemical activity, making it more likely to react with oxygen and other oxidizing substances in the environment.

[0004] The oxidation of silver nanowires can significantly affect their performance: First, the conductivity of silver oxide is much lower than that of metallic silver, so oxidation will reduce the conductivity of silver nanowires. Secondly, the oxide layer covers the surface of the silver nanowires, reducing its surface activity, thus affecting its effectiveness in applications such as catalysis and sensors. In addition, oxidation can also cause deformation of silver nanowires and may even lead to decomposition, which in turn affects their stability. Therefore, it is very important to avoid the oxidation of silver nanowires and improve the stability of the prepared silver nanowires. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing a high-stability nano silver wire and a method for preparing a flexible transparent electrode using the nano silver wire. By introducing a thiol-modified chain segment into PVP, the thiol group can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process to form a stable disulfide, thereby preventing further oxidative damage caused by free radicals, so that the modified PVP has antioxidant ability, and then the modified PVP is used to prepare silver nanowires to improve the antioxidant ability of the prepared silver nanowires. This method has the advantages of simple operation, strong controllability, and suitability for large-scale production, and can be widely used in the preparation of silver nanowires with excellent stability, conductivity and optical properties. The prepared silver nanowires can be coated on a flexible substrate to prepare a flexible transparent electrode.

[0006] In order to achieve the above object, a method for preparing a high-stability nano silver wire is provided according to the present invention, the method comprising the following steps:

[0007] Preparation stages of thiol-modified PVP:

[0008] Step 1-1: Add vinyl pyrrolidone and an organic solvent into a three-necked flask, add initiator azobisisobutyronitrile, introduce nitrogen and raise the temperature to a certain level;

[0009] Step 1-2: adding hydroxyethyl acrylate dropwise while stirring, and continuing the reaction for a period of time after the addition is completed to obtain a polyvinyl pyrrolidone-hydroxyethyl acrylate copolymer;

[0010] Step 1-3: adding 40% hydrogen bromide solution to the reaction solution and reacting for a period of time to obtain polyvinyl pyrrolidone-brominated hydroxyethyl acrylate copolymer;

[0011] Step 1-4: adding sodium hydrosulfide, filtering to remove impurities after a period of reaction, and drying to obtain powdered thiol-modified PVP;

[0012] Nano silver wire preparation stage:

[0013] Step 2-1: Take a certain amount of thiol-modified PVP, add it to ethylene glycol, and stir to mix evenly;

[0014] Step 2-2: Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution using a peristaltic pump, and continue the reaction for 1 hour after the addition;

[0015] Step 2-3: The reaction solution is cooled to room temperature, anhydrous ethanol is added and centrifuged and washed multiple times to prepare nano silver wires.

[0016] Preferably, in step 1-1, the organic solvent is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0017] Preferably, in step 1-2, the mass ratio of vinyl pyrrolidone, organic solvent, azobisisobutyronitrile and hydroxyethyl acrylate is 100:50-300:1-5:10-100.

[0018] Preferably, in step 1-1, the reaction temperature is 60-90° C.; in step 1-2, the dripping speed of hydroxyethyl acrylate is 0.5-5 g / min, and the reaction time after the dripping is completed is 2-4 h.

[0019] Preferably, in step 1-3, the mass ratio of hydrogen bromide to hydroxyethyl acrylate is 10-40:100, and the reaction time is 1-4 hours.

[0020] Preferably, in step 1-4, the mass ratio of sodium hydrosulfide to hydroxyethyl acrylate is 20-50:100, and the reaction time is 2-4 hours.

[0021] Preferably, in step 2-2, the mass ratio of mercapto-modified PVP, ethylene glycol and cupric chloride is 1-3:100:0.01-0.1.

[0022] Preferably, in step 2-2, the concentration of the ethylene glycol solution of silver nitrate is 1 to 3 g / 100 ml, the amount added is 100 ml, the dropping time is 1 to 3 h, and the reaction temperature is 120 to 200°C.

[0023] Preferably, in step 2-3, the concentration of the silver nanowires dispersed in ethanol is 0.1-5 mg / ml.

[0024] A method for preparing a flexible transparent electrode comprises the following steps: dispersing prepared nano silver wires in an ethanol solution to prepare a nano silver wire suspension; spraying the nano silver wire suspension on a PET film and drying to prepare a flexible transparent electrode.

[0025] It can be seen from the above technical scheme that the embodiments of the present invention have the following advantages: the present invention prepares thiol-modified PVP, and the thiol can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process to form a stable disulfide, thereby preventing further oxidative damage caused by free radicals, so that the thiol-modified PVP has antioxidant ability, and the silver nanowires are prepared using thiol-modified PVP to improve the antioxidant ability of the prepared silver nanowires; the flexible transparent electrode disperses the nano silver wires in an ethanol solution, and then sprays them on a PET film and dries to prepare a flexible transparent electrode. The technical scheme of the present invention has the advantages of simple operation, strong controllability, and suitability for large-scale production. It can be widely used in the preparation of silver nanowires with excellent stability, conductivity and optical properties, and the silver nanowires can be coated on a flexible substrate to prepare a flexible transparent electrode. DETAILED DESCRIPTION

[0026] The main purpose of the present invention is to provide a method for preparing a high-stability nano silver wire and a method for preparing a flexible transparent electrode using the nano silver wire. By introducing a thiol-modified chain segment into PVP, the thiol group can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process to form a stable disulfide, thereby preventing further oxidative damage caused by free radicals, so that the modified PVP has antioxidant ability, and then the modified PVP is used to prepare silver nanowires to improve the antioxidant ability of the prepared silver nanowires. This method has the advantages of simple operation, strong controllability, and suitability for large-scale production, and can be widely used in the preparation of silver nanowires with excellent stability, conductivity and optical properties. The prepared silver nanowires can be coated on a flexible substrate to prepare a flexible transparent electrode.

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all 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.

[0028] The present invention provides a method for preparing a high-stability nano silver wire, the method comprising the following steps:

[0029] Preparation stages of thiol-modified PVP:

[0030] Step 1-1: Add vinyl pyrrolidone and an organic solvent into a three-necked flask, add initiator azobisisobutyronitrile, introduce nitrogen and raise the temperature to a certain level;

[0031] Step 1-2: adding hydroxyethyl acrylate dropwise while stirring, and continuing the reaction for a period of time after the addition is completed to obtain a polyvinyl pyrrolidone-hydroxyethyl acrylate copolymer;

[0032] Step 1-3: adding 40% hydrogen bromide solution to the reaction solution and reacting for a period of time to obtain polyvinyl pyrrolidone-brominated hydroxyethyl acrylate copolymer;

[0033] Step 1-4: adding sodium hydrosulfide, filtering to remove impurities after a period of reaction, and drying to obtain powdered thiol-modified PVP;

[0034] In the preparation process of thiol-modified PVP, the reaction chemical formula is as follows:

[0035]

[0036] Nano silver wire preparation stage:

[0037] Step 2-1: Take a certain amount of thiol-modified PVP, add it to ethylene glycol, and stir to mix evenly;

[0038] Step 2-2: Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution using a peristaltic pump, and continue the reaction for 1 hour after the addition;

[0039] Step 2-3: The reaction solution is cooled to room temperature, anhydrous ethanol is added and centrifuged and washed multiple times to prepare nano silver wires.

[0040] In the preparation and production of nano silver wires, the polyol method is usually used to reduce silver salts to metallic silver in a high-boiling polyol solution to form a nanoscale silver wire structure. In this process, the polyol not only acts as a reaction solvent, but also acts as a reducing agent to reduce silver ions to metallic silver.

[0041] In production practice, polyvinyl pyrrolidone (PVP) is usually added as a stabilizer to control the growth direction and morphology of silver nanowires and prevent them from agglomerating and precipitating. On this basis, the present invention introduces thiol-modified segments into the PVP material. The thiol group can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process, forming stable disulfides to prevent further oxidative damage caused by free radicals, thereby making the modified PVP have antioxidant capacity, and then using the modified PVP to prepare silver nanowires to improve the antioxidant capacity of the prepared silver nanowires. This method has the advantages of simple operation, strong controllability, and suitability for large-scale production, and can be widely used in the preparation of silver nanowires with excellent stability, conductivity and optical properties. The prepared silver nanowires can be coated on a flexible substrate to prepare a flexible transparent electrode.

[0042] Preferably, in step 1-1, the organic solvent is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0043] Preferably, in step 1-2, the mass ratio of vinyl pyrrolidone, organic solvent, azobisisobutyronitrile and hydroxyethyl acrylate is 100:50-300:1-5:10-100.

[0044] Preferably, in step 1-1, the reaction temperature is 60-90° C.; in step 1-2, the dripping speed of hydroxyethyl acrylate is 0.5-5 g / min, and the reaction time after the dripping is completed is 2-4 h.

[0045] Preferably, in step 1-3, the mass ratio of hydrogen bromide to hydroxyethyl acrylate is 10-40:100, and the reaction time is 1-4 hours.

[0046] Preferably, in step 1-4, the mass ratio of sodium hydrosulfide to hydroxyethyl acrylate is 20-50:100, and the reaction time is 2-4 hours.

[0047] Preferably, in step 2-2, the mass ratio of mercapto-modified PVP, ethylene glycol and cupric chloride is 1-3:100:0.01-0.1.

[0048] Preferably, in step 2-2, the concentration of the ethylene glycol solution of silver nitrate is 1 to 3 g / 100 ml, the amount added is 100 ml, the dropping time is 1 to 3 h, and the reaction temperature is 120 to 200°C.

[0049] Preferably, in step 2-3, the concentration of the silver nanowires dispersed in ethanol is 0.1-5 mg / ml.

[0050] A method for preparing a flexible transparent electrode comprises the following steps: dispersing prepared nano silver wires in an ethanol solution to prepare a nano silver wire suspension; spraying the nano silver wire suspension on a PET film and drying to prepare a flexible transparent electrode.

[0051] The effects of the present invention are described below through a number of embodiments and comparative examples:

[0052] Example 1

[0053] Preparation of thiol-modified PVP: 100g of vinylpyrrolidone and 200g of toluene were added to a three-necked flask, 2g of initiator azobisisobutyronitrile was added, nitrogen was introduced and the temperature was raised to 80°C. 50g of hydroxyethyl acrylate was added dropwise while stirring at a dropping speed of 1g / min. After the addition was completed, the reaction was continued for 3h to obtain polyvinylpyrrolidone-hydroxyethyl acrylate copolymer. 10g of hydrogen bromide solution was added to the reaction solution and reacted for 3h to obtain polyvinylpyrrolidone-brominated hydroxyethyl acrylate copolymer. 15g of sodium hydrosulfide was added, and after reacting for 2h, impurities were removed by filtration and dried to obtain thiol-modified PVP powder.

[0054] Example 2

[0055] Preparation of flexible transparent electrode: Take 2g of modified PVP in Example 1, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 160°C, add 0.05g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 1g / 100ml silver nitrate using a peristaltic pump, add it dropwise for 1h, and continue to react for 1h after adding. Cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washing, and disperse the prepared nanosilver wires in an ethanol solution to prepare a dispersion with a concentration of 1mg / ml. Spray the nanosilver wires on a PET film and dry it to obtain a flexible transparent electrode.

[0056] Example 3

[0057] Preparation of thiol-modified PVP: Add 100g of vinylpyrrolidone and 250g of dimethylformamide to a three-necked flask, add 1.5g of initiator azobisisobutyronitrile, pass nitrogen and raise the temperature to 70°C. Add 60g of hydroxyethyl acrylate dropwise while stirring at a dropping speed of 2g / min. After the addition is complete, continue to react for 2h to obtain polyvinylpyrrolidone-hydroxyethyl acrylate copolymer. Add 15g of hydrogen bromide to the reaction solution and react for 2h to obtain polyvinylpyrrolidone-brominated hydroxyethyl acrylate copolymer. Add 20g of sodium hydrosulfide, react for 3h, filter to remove impurities, and dry to obtain thiol-modified PVP powder.

[0058] Example 4

[0059] Preparation of flexible transparent electrode: Take 1.5g of modified PVP in Example 3, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 170°C, add 0.06g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 2g / 100ml silver nitrate using a peristaltic pump, add it dropwise over 3h, and continue to react for 1h after adding. Cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washings, and disperse the prepared nanosilver wires in an ethanol solution to prepare a dispersion with a concentration of 1.5mg / ml. Spray the nanosilver wires on a PET film and dry it to obtain a flexible transparent electrode.

[0060] Example 5

[0061] Preparation of thiol-modified PVP: Add 100g of vinyl pyrrolidone and 150g of methyl pyrrolidone to a three-necked flask, add 1g of initiator azobisisobutyronitrile, pass nitrogen and raise the temperature to 85°C. Add 40g of hydroxyethyl acrylate dropwise while stirring at a dropping rate of 1.5g / min. After the addition is completed, continue to react for 3h to obtain polyvinyl pyrrolidone-hydroxyethyl acrylate copolymer. Add 12g of hydrogen bromide to the reaction solution and react for 2h to obtain polyvinyl pyrrolidone-brominated hydroxyethyl acrylate copolymer. Add 18g of sodium hydrosulfide, react for 2.5h, filter to remove impurities, and dry to obtain thiol-modified PVP powder.

[0062] Example 6

[0063] Preparation of flexible transparent electrode: Take 1.2g of modified PVP in Example 5, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 180°C, add 0.04g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 1.5g / 100ml silver nitrate using a peristaltic pump, add it dropwise over 2h, and continue to react for 1h after adding. Cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washings, and disperse the prepared nanosilver wires in an ethanol solution to prepare a dispersion with a concentration of 2mg / ml. Spray the nanosilver wires on a PET film and dry it to obtain a flexible transparent electrode.

[0064] Comparative Example 1

[0065] Preparation of PVP: 100 g of vinyl pyrrolidone and 200 g of toluene were added into a three-necked flask, and 2 g of initiator azobisisobutyronitrile was added. Nitrogen was introduced and the temperature was raised to 80°C. The reaction was continued for 3 h to obtain polyvinyl pyrrolidone, which was then dried to obtain PVP powder.

[0066] Comparative Example 2

[0067] Preparation of flexible transparent electrode: Take 2g of modified PVP in comparative example 1, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 160°C, add 0.05g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 1g / 100ml silver nitrate using a peristaltic pump, add it dropwise for 1h, and continue to react for 1h after adding. Cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washings, and disperse the prepared nanosilver wires in an ethanol solution to prepare a dispersion with a concentration of 1mg / ml. Spray the nanosilver wires on a PET film and dry it to obtain a flexible transparent electrode.

[0068] Comparative Example 3

[0069] Preparation of PVP: Add 100g of vinyl pyrrolidone and 150g of methyl pyrrolidone into a three-necked flask, add 1g of initiator azobisisobutyronitrile, pass nitrogen and raise the temperature to 85°C, react for 3h to obtain polyvinyl pyrrolidone, and dry to obtain PVP powder.

[0070] Comparative Example 4

[0071] Preparation of flexible transparent electrode: Take 1.2g of PVP in comparative example 3, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 180°C, add 0.04g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 1.5g / 100ml silver nitrate using a peristaltic pump, add it dropwise over 2h, and continue to react for 1h after adding. Cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washings, and disperse the prepared nanosilver wires in an ethanol solution to prepare a dispersion with a concentration of 2mg / ml. Spray the nanosilver wires on a PET film and dry it to obtain a flexible transparent electrode.

[0072] The molecular weight of the prepared PVP was tested by gel permeation chromatography (GPC), and the results were as follows:

[0073] Serial number Example 1 Example 3 Example 5 Comparative Example 1 Comparative Example 3 Molecular weight / Mn 86300 98500 12900 84500 11800

[0074] It can be seen from the molecular weight data in the table that the molecular weight of PVP prepared in each embodiment and comparative example in the table is between 80,000 and 130,000, which can be used to prepare nano silver wires.

[0075] The visible light transmittance of the prepared flexible transparent electrode was tested using a UV-visible light spectrum scanning tester, and the results are as follows:

[0076] Serial number Example 2 Example 4 Example 6 Comparative Example 2 Comparative Example 4 Transmittance / % 92 91 89.5 91 89

[0077] From the transmittance of each embodiment and comparative example in the table, it can be seen that the transparent electrodes prepared using nano silver wires have good visible light transmittance, and the transmittance is between 89 and 92.

[0078] The square resistance of the prepared transparent electrode and the square resistance after being placed in air for one month were tested using a four-probe tester. The results are as follows:

[0079] Serial number Example 2 Example 4 Example 6 Comparative Example 2 Comparative Example 4 Initial square resistance / Ω 10.8 8.7 5.9 10.5 7.6 Later square resistance / Ω 11.3 9.2 6.8 22.4 18.9

[0080] The transparent electrode prepared with nanosilver wire has good conductivity, and the initial square resistance is between about 6 and 11. After being stored in the air for one month, the square resistance has decreased to a certain extent. The square resistance of the nanosilver wire containing modified PVP has decreased less, by less than 1Ω. The square resistance of the nanosilver wire prepared with ordinary PVP has decreased more, by more than 10Ω. This is because the thiol chain segments are introduced into the modified PVP. The thiol group can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process, forming stable disulfides to prevent further oxidative damage. The nanosilver wire prepared using modified PVP has good stability and antioxidant ability, which can greatly improve the stability of the prepared transparent electrode.

[0081] It can be seen from the above technical scheme that the embodiments of the present invention have the following advantages: the present invention prepares thiol-modified PVP, and the thiol can provide hydrogen atoms to neutralize the free radicals generated during the oxidation process to form a stable disulfide, thereby preventing further oxidative damage caused by free radicals, so that the thiol-modified PVP has antioxidant ability, and the silver nanowires are prepared using thiol-modified PVP to improve the antioxidant ability of the prepared silver nanowires; the flexible transparent electrode disperses the nano silver wires in an ethanol solution, and then sprays them on a PET film and dries to prepare a flexible transparent electrode. The technical scheme of the present invention has the advantages of simple operation, strong controllability, and suitability for large-scale production. It can be widely used in the preparation of silver nanowires with excellent stability, conductivity and optical properties, and the silver nanowires can be coated on a flexible substrate to prepare a flexible transparent electrode.

[0082] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing high-stability nano silver wire, characterized in that: The method comprises the following steps: Preparation stages of thiol-modified PVP: Step 1-1: Add vinyl pyrrolidone and an organic solvent into a three-necked flask, add initiator azobisisobutyronitrile, introduce nitrogen and raise the temperature to a certain level; Step 1-2: adding hydroxyethyl acrylate dropwise while stirring, and continuing the reaction for a period of time after the addition is completed to obtain a polyvinyl pyrrolidone-hydroxyethyl acrylate copolymer; Step 1-3: adding 40% hydrogen bromide solution to the reaction solution and reacting for a period of time to obtain polyvinyl pyrrolidone-brominated hydroxyethyl acrylate copolymer; Step 1-4: adding sodium hydrosulfide, filtering to remove impurities after a period of reaction, and drying to obtain powdered thiol-modified PVP; Nano silver wire preparation stage: Step 2-1: Take a certain amount of thiol-modified PVP, add it to ethylene glycol, and stir to mix evenly; Step 2-2: Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution using a peristaltic pump, and continue the reaction for 1 hour after the addition; Step 2-3: The reaction solution is cooled to room temperature, anhydrous ethanol is added and centrifuged and washed multiple times to prepare nano silver wires.

2. The method for preparing high-stability silver nanowires and transparent electrodes according to claim 1, characterized in that: In step 1-1, the organic solvent is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

3. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 1, characterized in that: In step 1-2, the mass ratio of vinyl pyrrolidone, organic solvent, azobisisobutyronitrile and hydroxyethyl acrylate is 100:50-300:1-5:10-100.

4. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 3, characterized in that: In step 1-1, the reaction temperature is 60-90° C.; in step 1-2, the dropping speed of hydroxyethyl acrylate is 0.5-5 g / min, and the reaction time after the dropping is completed is 2-4 h.

5. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 1, characterized in that: In step 1-3, the mass ratio of hydrogen bromide to hydroxyethyl acrylate is 10-40:100, and the reaction time is 1-4 hours.

6. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 1, characterized in that: In step 1-4, sodium hydrosulfide and hydroxyethyl acrylate are added in a mass ratio of 20 to 50:100, and the reaction time is 2 to 4 hours.

7. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 1, characterized in that: In step 2-2, the mass ratio of mercapto-modified PVP, ethylene glycol and cupric chloride is 1-3:100:0.01-0.

1.

8. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 7, characterized in that: In step 2-2, the concentration of silver nitrate ethylene glycol solution is 1-3 g / 100 ml, the addition amount is 100 ml, the dropwise addition time is 1-3 h, and the reaction temperature is 120-200° C.

9. The method for preparing high-stability nano silver wires and transparent electrodes according to claim 8, characterized in that: In step 2-3, the concentration of the silver nanowires dispersed in ethanol is 0.1-5 mg / ml.

10. A method for preparing a flexible transparent electrode, using the silver nanowire according to any one of claims 1 to 9, characterized in that: The following steps are involved: dispersing the prepared silver nanowires in an ethanol solution to prepare a silver nanowire suspension; The silver nanowire suspension was sprayed on the PET film and dried to produce a flexible transparent electrode.

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