Preparation method of high-conductivity silver nanowire transparent electrode

Abstract

The embodiment of the invention discloses a preparation method of a high-conductivity nanometer silver wire transparent electrode. The preparation method comprises the preparation steps of preparing polycycloolefin modified degradable PVP, preparing nanometer silver wires and preparing the high-conductivity nanometer silver wire transparent electrode. A degradable PVP material is prepared by introducing a degradable chain segment into a PVP chain segment, the degradable PVP material is used for preparing a nanometer silver wire, and a substrate material is coated with the nanometer silver wire to prepare a conductive electrode. The PVP material is removed through degradation of the degradable chain segment and washing of the solvent, so that the silver nanowire on the electrode is purified, the conductivity and transparency of the conductive electrode are improved, and the overall performance of the electrode is effectively improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of transparent electrodes, and in particular to a method for preparing a highly conductive nano silver wire transparent electrode. Background Art

[0002] At present, silver nanowires have become one of the ideal materials for making transparent conductive electrodes due to their excellent conductivity and flexibility. Silver nanowires usually have a diameter of tens to hundreds of nanometers and a length of several micrometers to tens of micrometers, which enables them to provide extremely low resistance and high transmittance when forming a network. Silver nanowires can be easily integrated into different substrates to prepare transparent electrodes through printing, spraying or other deposition techniques. Transparent electrodes prepared with silver nanowires can achieve efficient current transmission and good optical properties while maintaining the flexibility and durability of the material. It has great applications in touch screens, flexible displays, solar panels, and smart wearable devices.

[0003] In the synthesis process of silver nanowires, polyvinyl pyrrolidone (hereinafter referred to as PVP) is often used as a dispersant and stabilizer to prevent the aggregation of silver nanowires in the solution. PVP effectively stabilizes the size and shape of the silver wires by adsorbing on the surface of the silver wires, thereby maintaining their uniform distribution. However, when these silver nanowires are used to make transparent conductive electrodes, the presence of PVP will affect the performance of the final product. When the silver nanowires are coated on the substrate, PVP will also be coated, which may lead to an increase in the resistance of the electrode because PVP itself is not conductive. In addition, the presence of PVP may also affect the optical transparency and overall mechanical strength of the electrode. Therefore, although PVP plays a key role in the synthesis of silver nanowires, in subsequent applications, it may be necessary to remove or reduce PVP through appropriate post-treatment steps, such as heat treatment or chemical treatment, to improve the overall performance of the electrode.

[0004] Due to the strong interaction between PVP and silver nanowires, it is difficult to completely remove PVP by simple washing or solvent treatment. Although high-temperature treatment can decompose PVP, this high temperature usually needs to be greater than 200°C, which may cause aggregation or morphological changes in silver nanowires, thereby affecting their conductive properties. Due to the difficulty of PVP removal and its potential impact on the performance of silver nanowires, there are relatively few studies on this issue and a lack of systematic solutions. Therefore, studying more effective removal methods or finding new non-adhesive stabilizers is crucial to promoting the application of silver nanowires in advanced electronic technologies. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing a highly conductive nano silver wire transparent electrode, by introducing a degradable segment into a PVP segment, a degradable PVP material is prepared, and the nano silver wire is prepared by using the degradable PVP material and coated on a substrate material to prepare a conductive electrode. The conductivity and transparency of the conductive electrode are increased by degrading the degradable segment and removing the PVP material by washing with a solvent.

[0006] In order to achieve the above object, a method for preparing a highly conductive nano silver wire transparent electrode is provided according to the present invention, the method comprising the following steps:

[0007] Step S1: preparing polycycloolefin-modified degradable PVP;

[0008] A certain amount of cyclooctene is added to organic solvent A, stirred evenly under nitrogen atmosphere, and the temperature is controlled at 20-50°C; a small amount of Grubbs catalyst and chain transfer agent are added, and the reaction is continued for 0.5-1h, and then the reactant is poured into a large amount of methanol, and the bottom precipitate is taken and dried to obtain polycyclooctene;

[0009] A certain amount of polycyclooctene is added to organic solvent B, a small amount of azobisisobutyronitrile initiator is added, the temperature is raised to 40-80°C, and stirred under a nitrogen atmosphere to form a uniform polycycloolefin solution;

[0010] A certain amount of vinyl pyrrolidone is added to the organic solvent C, and the mixture is stirred and mixed to obtain a vinyl pyrrolidone solution;

[0011] The vinyl pyrrolidone solution is added dropwise to the polycycloolefin solution for 1 hour. After the addition is completed, the reaction is continued for 1 to 2 hours. After washing and drying, the polycycloolefin-modified degradable PVP is obtained.

[0012] Step S2: preparing silver nanowires;

[0013] Take a certain amount of polycycloolefin-modified biodegradable PVP, add it to ethylene glycol, and stir to mix evenly. Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution with a peristaltic pump, and continue to react for 1 hour after adding; cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washing, and disperse the prepared nano silver wire dispersion in the ethanol solution for use;

[0014] Step S3: preparing a highly conductive nanosilver wire transparent electrode;

[0015] The prepared nano silver wire solution is sprayed on glass, heated to 50-100° C., and the glass surface is washed with an organic solvent D containing a Grubbs catalyst, and then dried to obtain a highly conductive nano silver wire transparent electrode.

[0016] Preferably, in step S1, the mass ratio of cyclooctene to organic solvent A is (10-20):100; the amount of Grubbs catalyst added is 0.01-1% of the mass of cyclooctene; the amount of chain transfer agent added is 0.1%-5% of the mass of cyclooctene; the mass ratio of polycyclooctene to organic solvent B is (10-30):100; the amount of azobisisobutyronitrile added is 1%-5% of the mass of polycyclooctene; the mass ratio of vinylpyrrolidone to organic solvent C is (10-30):100; the mass ratio of vinylpyrrolidone to polycyclooctene is (50-200):100.

[0017] Preferably, the organic solvent A is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran and toluene.

[0018] Preferably, the organic solvent B is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0019] Preferably, the organic solvent C is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0020] Preferably, the Grubbs catalyst is a ruthenium carbene complex and a modified ruthenium carbene complex, and the chain transfer agent is a thiol or boron hydride.

[0021] Preferably, in step S2, the mass ratio of polycycloolefin-modified degradable PVP, ethylene glycol and cupric chloride is (1-3):100:(0.01-0.1).

[0022] Preferably, in step S2, the concentration of the ethylene glycol solution of silver nitrate is 1-3 g / 100 ml, the addition amount is 100 ml, the dropping time is 1-3 h, and the reaction temperature is 100-150° C.; the concentration of the nanosilver wires dispersed in ethanol is 0.1-5 mg / ml.

[0023] Preferably, in step S3, the solubility of the Grubbs catalyst is 0.1-5%.

[0024] Preferably, the organic solvent D is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran, toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0025] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0026] The present invention prepares a degradable PVP material by introducing a degradable segment into a PVP segment, and uses the degradable PVP material to prepare a nano silver wire and coats it on a substrate material to prepare a conductive electrode. The PVP material is removed by degrading the degradable segment and washing with a solvent, thereby purifying the nano silver wire on the electrode and increasing the conductivity and transparency of the conductive electrode. DETAILED DESCRIPTION

[0027] The main purpose of the present invention is to provide a method for preparing a highly conductive nano silver wire transparent electrode, by introducing a degradable segment into a PVP segment, a degradable PVP material is prepared, and the nano silver wire is prepared by using the degradable PVP material and coated on a substrate material to prepare a conductive electrode. The conductivity and transparency of the conductive electrode are increased by degrading the degradable segment and removing the PVP material by washing with a solvent.

[0028] 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.

[0029] The present invention provides a method for preparing a highly conductive nano silver wire transparent electrode, the method comprising the following steps:

[0030] Step S1: preparing polycycloolefin-modified degradable PVP;

[0031] A certain amount of cyclooctene is added to organic solvent A, stirred evenly under nitrogen atmosphere, and the temperature is controlled at 20-50°C; a small amount of Grubbs catalyst and chain transfer agent are added, and the reaction is continued for 0.5-1h, and then the reactant is poured into a large amount of methanol, and the bottom precipitate is taken and dried to obtain polycyclooctene;

[0032] A certain amount of polycyclooctene is added to organic solvent B, a small amount of azobisisobutyronitrile initiator is added, the temperature is raised to 40-80°C, and stirred under a nitrogen atmosphere to form a uniform polycycloolefin solution;

[0033] A certain amount of vinyl pyrrolidone is added to the organic solvent C, and the mixture is stirred and mixed to obtain a vinyl pyrrolidone solution;

[0034] The vinyl pyrrolidone solution is added dropwise to the polycycloolefin solution for 1 hour. After the addition is completed, the reaction is continued for 1 to 2 hours. After washing and drying, the polycycloolefin-modified degradable PVP is obtained.

[0035] Step S2: Preparation of silver nanowires

[0036] Take a certain amount of polycycloolefin-modified biodegradable PVP, add it to ethylene glycol, and stir to mix evenly. Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution with a peristaltic pump, and continue to react for 1 hour after adding; cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washing, and disperse the prepared nano silver wire dispersion in the ethanol solution for use;

[0037] Step S3: preparing a highly conductive nanosilver wire transparent electrode;

[0038] The prepared nano silver wire solution is sprayed on glass, heated to 50-100° C., and the glass surface is washed with an organic solvent D containing a Grubbs catalyst, and then dried to obtain a highly conductive nano silver wire transparent electrode.

[0039] Preferably, in step S1, the mass ratio of cyclooctene to organic solvent A is (10-20):100; the amount of Grubbs catalyst added is 0.01-1% of the mass of cyclooctene; the amount of chain transfer agent added is 0.1%-5% of the mass of cyclooctene; the mass ratio of polycyclooctene to organic solvent B is (10-30):100; the amount of azobisisobutyronitrile added is 1%-5% of the mass of polycyclooctene; the mass ratio of vinylpyrrolidone to organic solvent C is (10-30):100; the mass ratio of vinylpyrrolidone to polycyclooctene is (50-200):100.

[0040] Preferably, the organic solvent A is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran and toluene.

[0041] Preferably, the organic solvent B is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

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

[0043] Preferably, the Grubbs catalyst is a ruthenium carbene complex and a modified ruthenium carbene complex, and the chain transfer agent is a thiol or boron hydride.

[0044] Preferably, in step S2, the mass ratio of polycycloolefin-modified degradable PVP, ethylene glycol and cupric chloride is (1-3):100:(0.01-0.1).

[0045] Preferably, in step S2, the concentration of the ethylene glycol solution of silver nitrate is 1-3 g / 100 ml, the addition amount is 100 ml, the dropping time is 1-3 h, and the reaction temperature is 100-150° C.; the concentration of the nanosilver wires dispersed in ethanol is 0.1-5 mg / ml.

[0046] Preferably, in step S3, the solubility of the Grubbs catalyst is 0.1-5%.

[0047] Preferably, the organic solvent D is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran, toluene, dimethylformamide, dimethylacetamide and methylpyrrolidone.

[0048] In the preparation of the nano silver wire of the present invention, ethylene glycol, which has both solvent and reducing agent functions, is selected as a solvent because it has sufficient reducing ability, a relatively high boiling point and suitable viscosity; Cl- is selected as a controlling agent to react with Ag+ to generate insoluble silver halide to reduce the reduction rate of silver, and acts as a nucleating agent to provide initial crystallization sites; PVP, as a crystal surface protecting agent, is preferentially adsorbed on the {100} crystal surface on the side of the silver nanocrystal, helping to inhibit the growth of the silver nanocrystal along the diameter direction, thereby inducing it to grow into a silver nanowire along the {111} crystal surface in the longitudinal direction.

[0049] Cyclooctene is a cycloolefin that can undergo ring-opening metathesis polymerization (ROMP). ROMP is a chain growth polymerization reaction that uses a transition metal catalyst to open the ring structure of cycloolefins to form a polymer chain containing double bonds. In the ROMP reaction of cyclooctene, the catalyst (such as a Grignard reagent or a metal carbene complex) will insert into the carbon-carbon double bond of cyclooctene, break the ring structure, and form a reactive intermediate. This reactive intermediate will then react with another cyclooctene molecule, continue to break the ring and insert into the polymer chain, and finally form polycyclooctene.

[0050] The reversibility of the reaction is an important feature of ROMP. This means that polycyclooctene can undergo the reverse reaction, i.e. depolymerization, to reform cyclooctene monomer under the action of the same catalyst under appropriate conditions. This reversibility stems from the equilibrium nature of the ROMP reaction. When the reaction conditions change, such as temperature, catalyst concentration, etc., the equilibrium will shift in favor of the monomer or polymer. For example, increasing the temperature in the presence of a catalyst will promote the depolymerization of polycyclooctene to produce more cyclooctene monomer, and this depolymerization temperature can usually be between 50-100°C.

[0051] The ring-opening metathesis polymerization and depolymerization of cyclooctene are as follows:

[0052]

[0053] The invention prepares polycyclooctene by ring-opening metathesis polymerization, and then copolymerizes the polycyclooctene with vinylpyrrolidone to prepare modified PVP. The modified PVP contains depolymerizable polycyclooctene, and can be depolymerized into small molecular segments under heating conditions, and the small molecular segments can be easily removed by an organic solvent. The modified PVP is used to prepare nano silver wires and is coated on a substrate to form a conductive electrode, and then the PVP is removed to obtain a highly conductive conductive electrode.

[0054] The polymerization reaction of polycyclooctene and PVP is as follows:

[0055]

[0056] The degradation reaction of PVP is as follows:

[0057]

[0058] When Grubbs catalyst is added and heated, the polycyclooctene segments in the modified PVP will degrade to generate cyclooctene monomers and low molecular weight vinyl pyrrolidone segments, which can be easily removed by organic solvents. The modified PVP is used to prepare nanosilver wires, and then the PVP is removed after the conductive electrode is prepared, which can greatly improve the conductivity and transparency of the conductive electrode.

[0059] The present technical solution is described in detail below through six embodiments and four comparative examples:

[0060] Example 1

[0061] Preparation of degradable PVP: Take 10g of cyclooctene and add it to 100g of chloroform, stir evenly under a nitrogen atmosphere, and control the temperature at 30°C. Add 0.05g of Grubbs catalyst and 0.2g of thiol, continue the reaction for 1h, pour the reactant into a large amount of methanol, take the bottom precipitate and dry it to obtain polycyclooctene. Take 20g of polycycloolefin and add it to 100g of toluene, add 0.6g of azobisisobutyronitrile initiator, heat it to 60°C, and stir it under a nitrogen atmosphere to form a uniform polycycloolefin solution. Take 15g of vinyl pyrrolidone and add it to 100g of toluene, stir and mix evenly, add the vinyl pyrrolidone solution dropwise to the polycycloolefin solution, add it dropwise for 1h, continue the reaction for 1h after the addition is completed, and obtain polycycloolefin modified degradable PVP1 after washing and drying.

[0062] Example 2

[0063] Preparation of highly conductive nano silver wire electrode: Take 1.5g of the degradable PVP in Example 1, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 160°C, add 0.04g 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 nano silver wire in an ethanol solution to prepare a dispersion with a concentration of 1mg / ml. Spray the nano silver wire on the glass, heat to 60°C, and wash the glass surface with 3% Grubbs catalyst dimethylformamide, and dry to obtain a highly conductive nano silver wire transparent electrode.

[0064] Example 3

[0065] Preparation of degradable PVP: Take 12g of cyclooctene and add it to 100g of chloroform, stir evenly under a nitrogen atmosphere, and control the temperature at 35°C. Add 0.08g of Grubbs catalyst and 0.3g of thiol, continue the reaction for 1h, pour the reactant into a large amount of methanol, take the bottom precipitate and dry it to obtain polycyclooctene. Take 20g of polycycloolefin and add it to 100g of dimethylformamide, add 0.4g of azobisisobutyronitrile initiator, heat it to 60°C, and stir it under a nitrogen atmosphere to form a uniform polycycloolefin solution. Take 18g of vinylpyrrolidone and add it to 100g of dimethylformamide, stir and mix evenly, add the vinylpyrrolidone solution dropwise to the polycycloolefin solution, add it dropwise for 1h, continue the reaction for 1.5h after the addition is completed, and obtain polycycloolefin modified degradable PVP2 after washing and drying.

[0066] Example 4

[0067] Preparation of highly conductive nanosilver wire electrode: Take 1.8g of the degradable 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 1.5g / 100ml silver nitrate using a peristaltic pump, add it dropwise for 1.5h, 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 wire in an ethanol solution to prepare a dispersion with a concentration of 1.2mg / ml. Spray the nanosilver wire on the glass, heat to 70°C, and wash the glass surface with a toluene solution of 2% Grubbs catalyst. After drying, a highly conductive nanosilver wire transparent electrode is obtained.

[0068] Example 5

[0069] Preparation of degradable PVP: Take 20g of cyclooctene and add it to 100g of chloroform, stir evenly under a nitrogen atmosphere, and control the temperature at 35°C. Add 0.15g of Grubbs catalyst and 0.2g of thiol, continue the reaction for 1h, pour the reactant into a large amount of methanol, take the bottom precipitate and dry it to obtain polycyclooctene. Take 15g of polycycloolefin and add it to 100g of methyl pyrrolidone, add 0.3g of azobisisobutyronitrile initiator, heat it to 70°C, and stir it under a nitrogen atmosphere to form a uniform polycycloolefin solution. Take 20g of vinyl pyrrolidone and add it to 100g of methyl pyrrolidone, stir and mix evenly, add the vinyl pyrrolidone solution dropwise to the polycycloolefin solution, add it dropwise for 1h, continue the reaction for 2h after the addition is completed, and obtain polycycloolefin modified degradable PVP3 after washing and drying.

[0070] Example 6

[0071] Preparation of highly conductive nano silver wire electrode: Take 2g of the degradable PVP in Example 5, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 160°C, add 0.04g 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 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 nano silver wire in an ethanol solution to prepare a dispersion with a concentration of 0.8mg / ml. Spray the nano silver wire on the glass, heat to 80°C, and wash the glass surface with a 3.5% Grubbs catalyst methyl pyrrolidone solution, and obtain a highly conductive nano silver wire transparent electrode after drying.

[0072] Comparative Example 1

[0073] Preparation of PVP: Add 100g of vinyl pyrrolidone and 180g of dimethylformamide into a three-necked flask, add 3g of initiator azobisisobutyronitrile, pass nitrogen and raise the temperature to 65°C, continue the reaction for 3h to obtain polyvinyl pyrrolidone, and dry to obtain PVP powder.

[0074] Comparative Example 2

[0075] Preparation of silver nanowires: Take 1.8g of the modified PVP in Comparative Example 1, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 170°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 silver nanowires in an ethanol solution to prepare a dispersion with a concentration of 1mg / ml. Spray the silver nanowires on a glass film and dry it to obtain a transparent electrode.

[0076] Comparative Example 3

[0077] Preparation of PVP: Add 100g of vinyl pyrrolidone and 140g of methyl pyrrolidone into a three-necked flask, add 1.5g of initiator azobisisobutyronitrile, pass nitrogen and raise the temperature to 80°C, react for 1h to obtain polyvinyl pyrrolidone, and dry to obtain PVP powder.

[0078] Comparative Example 4

[0079] Preparation of silver nanowires: Take 1.5g of PVP in comparative example 3, add it to 100g of ethylene glycol, and stir to mix evenly. Heat to 160°C, add 0.06g of cupric chloride and mix evenly, slowly add 100ml of ethylene glycol solution with a concentration of 1.7g / 100ml silver nitrate using a peristaltic pump, add it dropwise over 1.5h, 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 silver nanowires in an ethanol solution to prepare a dispersion with a concentration of 1.4mg / ml. Spray the silver nanowires on glass and dry to obtain a transparent electrode.

[0080] The molecular weight of the prepared polycyclooctene was tested by gel permeation chromatography (GPC), and the results were as follows:

[0081] Serial number Example 1 Example 3 Example 5 Molecular weight / Mn 2580 3520 5470

[0082] The molecular weight of the prepared polycyclooctene is between 2500 and 5500, and the molecular weight can be further increased by polymerization.

[0083] The molecular weight of the prepared degradable PVP was tested by gel permeation chromatography (GPC), and the results were as follows:

[0084]

[0085] The prepared degradable PVP has a molecular weight between 100,000 and 150,000 and can be used to prepare nano silver wires.

[0086] The visible light transmittance of the transparent electrodes without removing PVP in Examples 2, 4, and 6 was tested using a UV-visible light spectrum scanning tester, and the results were as follows:

[0087] Serial number Example 2 Example 4 Example 6 Transmittance / % 90.4 89.8 89.6

[0088] The visible light transmittance of the prepared transparent electrode was tested using a UV-visible light spectrum scanning tester, and the results are as follows:

[0089] Serial number Example 2 Example 4 Example 6 Comparative Example 2 Comparative Example 4 Transmittance / % 92.2 91.8 92.3 90.2 89.6

[0090] The transparent electrodes prepared with nano silver wires have good visible light transmittance. The transmittance of the transparent electrode containing PVP is about 90%, and the transmittance of the transparent electrode without PVP will increase to about 92%.

[0091] The square resistance of the transparent electrode without removing the PVP in Examples 2, 4, and 6 was tested by a four-probe tester, and the results were as follows:

[0092] Serial number Example 2 Example 4 Example 6 Square resistance / Ω 10.7 11.5 9.3

[0093] The square resistance of the prepared transparent electrode was tested using a four-probe tester, and the results are as follows:

[0094]

[0095]

[0096] The square resistance of the transparent electrode prepared with PVP is between 9 and 11Ω, and the square resistance of the transparent electrode without PVP is between 4.3 and 5.2Ω. Removing PVP can effectively improve the conductivity of the prepared transparent electrode.

[0097] It can be seen from the above technical scheme that the present invention prepares a degradable PVP material by introducing a degradable segment into the PVP segment, and uses the degradable PVP material to prepare nanosilver wires and coats them on a substrate material to prepare a conductive electrode. The PVP material is removed by degradation of the degradable segment and washing with a solvent, thereby purifying the nanosilver wires on the electrode and increasing the conductivity and transparency of the conductive electrode.

[0098] 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 a highly conductive nano silver wire transparent electrode, characterized in that: The method comprises the following steps: Step S1: preparing polycycloolefin-modified degradable PVP; A certain amount of cyclooctene is added to organic solvent A, stirred evenly under nitrogen atmosphere, and the temperature is controlled at 20-50°C; a small amount of Grubbs catalyst and chain transfer agent are added, and the reaction is continued for 0.5-1h, and then the reactant is poured into a large amount of methanol, and the bottom precipitate is taken and dried to obtain polycyclooctene; A certain amount of polycyclooctene is added to organic solvent B, a small amount of azobisisobutyronitrile initiator is added, the temperature is raised to 40-80°C, and stirred under a nitrogen atmosphere to form a uniform polycycloolefin solution; A certain amount of vinyl pyrrolidone is added to the organic solvent C, and the mixture is stirred and mixed to obtain a vinyl pyrrolidone solution; The vinyl pyrrolidone solution is added dropwise to the polycycloolefin solution for 1 hour. After the addition is completed, the reaction is continued for 1 to 2 hours. After washing and drying, the polycycloolefin-modified degradable PVP is obtained. Step S2: preparing silver nanowires; Take a certain amount of polycycloolefin-modified biodegradable PVP, add it to ethylene glycol, and stir to mix evenly. Heat to a certain temperature, drop a small amount of cupric chloride and mix evenly, slowly add silver nitrate ethylene glycol solution with a peristaltic pump, and continue to react for 1 hour after adding; cool the reaction solution to room temperature, add anhydrous ethanol for multiple centrifugal washing, and disperse the prepared nano silver wire dispersion in the ethanol solution for use; Step S3: preparing a highly conductive nanosilver wire transparent electrode; The prepared nano silver wire solution is sprayed on glass, heated to 50-100° C., and the glass surface is washed with an organic solvent D containing a Grubbs catalyst, and then dried to obtain a highly conductive nano silver wire transparent electrode.

2. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 1, characterized in that: In step S1, the mass ratio of cyclooctene to organic solvent A is (10-20):100; the amount of Grubbs catalyst added is 0.01-1% of the mass of cyclooctene; the amount of chain transfer agent added is 0.1%-5% of the mass of cyclooctene; the mass ratio of polycyclooctene to organic solvent B is (10-30):100; the amount of azobisisobutyronitrile added is 1%-5% of the mass of polycyclooctene; the mass ratio of vinyl pyrrolidone to organic solvent C is (10-30):100; the mass ratio of vinyl pyrrolidone to polycyclooctene is (50-200):

100.

3. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 2, characterized in that: The organic solvent A is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran and toluene.

4. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 2, characterized in that: The organic solvent B is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methyl pyrrolidone.

5. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 2, characterized in that: The organic solvent C is any one or more combinations of toluene, dimethylformamide, dimethylacetamide and methyl pyrrolidone.

6. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 2, characterized in that: The Grubbs catalyst is a ruthenium carbene complex and an improved ruthenium carbene complex, and the chain transfer agent is a mercaptan or boron hydride.

7. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 1, characterized in that: In step S2, the mass ratio of polycycloolefin-modified degradable PVP, ethylene glycol and cupric chloride is (1-3):100:(0.01-0.1).

8. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 7, characterized in that: In step S2, the concentration of silver nitrate ethylene glycol solution is 1-3 g / 100 ml, the addition amount is 100 ml, the dropping time is 1-3 h, and the reaction temperature is 100-150° C.; the concentration of nano silver wires dispersed in ethanol is 0.1-5 mg / ml.

9. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 1, characterized in that: In step S3, the solubility of the Grubbs catalyst is 0.1-5%.

10. The method for preparing a highly conductive nano silver wire transparent electrode according to claim 9, characterized in that: The organic solvent D is any one or more combinations of dichloromethane, chloroform, tetrahydrofuran, toluene, dimethylformamide, dimethylacetamide and methyl pyrrolidone.

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