Preparation process and application of silver nanowire conductive film

Abstract

The invention provides a preparation process and application of a silver nanowire conductive film, and relates to the field of home kitchens. The preparation process of the silver nanowire conductive film comprises the following specific steps: S1, synthesizing core-shell particles; S11, preparing the following raw materials: 1.7 g of silver nitrate, 4.34 g of cerous nitrate and 0.05 mol / L of sodium citrate; s12, a preparation process: firstly, dissolving silver nitrate and cerous nitrate in 500mL of deionized water, carrying out water bath at a constant temperature of 80 DEG C, then dropwise adding 1M of NaOH until the pH value is 9.0, magnetically stirring for 2 hours, centrifugally separating, and washing with ethanol for three times to obtain slurry; s2, preparing a silver nanowire conductive film: mixing the slurry with carboxylated carbon nanotubes, fluorosilicone epoxy, ascorbic acid and chitosan according to a mass ratio of 25: 8: 60: 5: 2, and defoaming after planetary stirring; s3, post-treatment is conducted; S31, annealing strengthening is conducted, specifically, annealing is conducted for 1 h at 300 DEG C under nitrogen protection; and S32, surface modification: 3-aminopropyltriethoxysilane is used for modification, the concentration is 1 wt%, and the reaction is performed for 4 h at the temperature of 60 DEG C. Due to the composition of the core-shell particles, migration of silver can be prevented, and the problem of resistance improvement is effectively solved after repeated recycling.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment maintenance, and in particular to a preparation process and application of a nano silver wire conductive film. Background Art

[0002] Power equipment mainly includes two categories: power generation equipment and power supply equipment. When the cable joints, knife switches and transformer contacts in the power supply equipment are damaged, they usually need to be repaired with repair agents.

[0003] The repairing agent in the prior art has the following defects: 1. After thermal cycling (-40°C-120°C), the conductive network of traditional conductive pastes breaks down, and the contact resistance recovery rate is >30% (for example, the resistance of a certain power grid repair paste increased from 0.01Ω to 0.13Ω after six months). Causes: Aggregation of nanosilver particles: High surface energy drives the migration and aggregation of silver particles (TEM shows that the particle size increases from 20nm to 200nm after cycling); Debonding of the carbon carrier-matrix interface: Difference in thermal expansion coefficient (CTE: 60×10 -6 / K vs 0.5×10 -6 / K); 2. In a humid environment (RH>85%), silver oxidizes (Ag→Ag2O), causing a conductivity loss of >50%. High temperatures (100°C) cause resin degradation, with adhesion dropping by ≥2 levels. Reasons: Silver is highly chemically active, reacting with H2O / O2 to form insulating oxides. The resin has poor weather resistance, resulting in hydrolysis and chain scission in a hot and humid environment (FTIR shows an ester bond rupture peak). 3. Silver ion migration and the formation of Ag2S insulating layer in sulfide environment (H2S) shortens the life by >70%; Reason: No ion blocking mechanism: Free Ag + Easy to dissolve; lack of chemical corrosion resistance design. Summary of the Invention

[0004] (1) Technical problems solved In view of the shortcomings of the existing technology, the present invention provides a preparation process and application of a nano silver wire conductive film, which solves the problems raised by the background technology.

[0005] (2) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: A preparation process of a nano silver wire conductive film includes the following specific steps: S1. Synthesis of core-shell particles S11, raw material composition: silver nitrate 1.7g, cerium nitrate 4.34g, sodium citrate 0.05mol / L; S12. Preparation process: First, silver nitrate and cerium nitrate were dissolved in 500 mL of deionized water, kept constant at 80°C in a water bath, and then 1 M NaOH was added dropwise until the pH value was 9.0. The mixture was magnetically stirred for 2 h, centrifuged, and washed with ethanol three times to obtain a slurry. S2, nanosilver wire conductive film: the slurry was mixed with carboxylated carbon nanotubes, fluorosilicon epoxy, ascorbic acid, and chitosan in a mass ratio of 25:8:60:5:2, and degassed after planetary stirring; S3, post-processing S31, annealing strengthening: annealing at 300℃ for 1h under nitrogen protection; S32. Surface modification: Modify with 3-aminopropyltriethoxysilane, concentration 1wt%, 60℃ for 4h.

[0006] Preferably, the rotation speed of the magnetic stirring in S12 is 500 rpm, the rotation speed of the centrifugal separation is 12000 rpm, and the time is 10 min.

[0007] Preferably, the planetary stirring in S2 has an orbital speed of 2000 rpm and an autorotation speed of 800 rpm for 30 minutes.

[0008] Preferably, the degassing in S2 is performed by vacuum degassing with a pressure of -0.1 MPa and a time of 5 minutes.

[0009] A preparation process of a nano silver wire conductive film is applied to the maintenance of power equipment.

[0010] (3) Beneficial effects The present invention provides a preparation process and application of a nanosilver wire conductive film. It has the following beneficial effects: 1. The composition of the core-shell particles of the present invention can prevent silver from migrating and effectively solve the problem of increased resistance after multiple cycles of use.

[0011] 2. In the present invention, S2 and S3 adopt CeO2 coating technology to coat the surface of silver with an oxide barrier layer, thereby solving the problem of silver being oxidized in a humid environment.

[0012] 3. The present invention, by adding chitosan and utilizing chitosan derivatives to capture silver ions, effectively solves the problem of anion dissolution and ensures the performance of chemical corrosion resistance. DETAILED DESCRIPTION

[0013] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0014] Example: The present invention provides a process for preparing a silver nanowire conductive film, comprising the following specific steps: S1. Synthesis of core-shell particles S11, raw material composition: silver nitrate 1.7g, cerium nitrate 4.34g, sodium citrate 0.05mol / L; S12. Preparation process: First, silver nitrate and cerium nitrate were dissolved in 500 mL of deionized water, kept constant at 80°C in a water bath, and then 1 M NaOH was added dropwise until the pH value was 9.0. The mixture was magnetically stirred for 2 h, centrifuged, and washed with ethanol three times to obtain a slurry. S2, nanosilver wire conductive film: the slurry was mixed with carboxylated carbon nanotubes, fluorosilicon epoxy, ascorbic acid, and chitosan in a mass ratio of 25:8:60:5:2, and degassed after planetary stirring; S3, post-processing S31, annealing strengthening: annealing at 300℃ for 1h under nitrogen protection; S32. Surface modification: Modify with 3-aminopropyltriethoxysilane, concentration 1wt%, 60℃ for 4h.

[0015] The speed of magnetic stirring in S12 is 500 rpm, the speed of centrifugal separation is 12000 rpm, and the time is 10 min. The revolution of planetary stirring in S2 is 2000 rpm, the rotation is 800 rpm, and the time is 30 min. The degassing in S2 adopts vacuum degassing method with a pressure of -0.1 MPa and a time of 5 min.

[0016] S1 mainly forms core-shell particles, which can prevent the migration of silver and effectively solve the problem of increased resistance after multiple cycles of use.

[0017] Among them, S2 and S3 use CeO2 coating technology to coat the surface of silver with an oxide barrier layer, thereby solving the problem of silver being oxidized in a humid environment.

[0018] By adding chitosan and using chitosan derivatives to capture silver ions, the problem of anion dissolution is effectively solved, ensuring the performance of chemical corrosion resistance.

[0019] A preparation process of a nano silver wire conductive film is applied to the maintenance of power equipment.

[0020] Table 1 shows the conductive stability (core power index)

[0021] Table 2 shows the shell thickness optimization test

[0022] The test methods used in Table 2 are: Shell thickness: TEM (JEOL JEM-2100, accelerating voltage 200 kV) Ag valence state: XPS (Thermo K-Alpha, binding energy calibrated to C1s 284.8 eV) Table 3 is a data table comparing the present invention with the prior art

[0023] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a silver nanowire conductive film, characterized by: The specific steps include: S1. Synthesis of core-shell particles S11, raw material composition: silver nitrate 1.7g, cerium nitrate 4.34g, sodium citrate 0.05mol / L; S12. Preparation process: First, silver nitrate and cerium nitrate were dissolved in 500 mL of deionized water, kept constant at 80°C in a water bath, and then 1 M NaOH was added dropwise until the pH value was 9.

0. The mixture was magnetically stirred for 2 h, centrifuged, and washed with ethanol three times to obtain a slurry. S2, nanosilver wire conductive film: the slurry was mixed with carboxylated carbon nanotubes, fluorosilicon epoxy, ascorbic acid, and chitosan in a mass ratio of 25:8:60:5:2, and degassed after planetary stirring; S3, post-processing S31, annealing strengthening: annealing at 300℃ for 1h under nitrogen protection; S32. Surface modification: Modify with 3-aminopropyltriethoxysilane, concentration 1wt%, 60℃ for 4h.

2. The process for preparing a silver nanowire conductive film according to claim 1, wherein: The rotation speed of the magnetic stirring in S12 is 500 rpm, the rotation speed of the centrifugal separation is 12000 rpm, and the time is 10 min.

3. The process for preparing a silver nanowire conductive film according to claim 1, wherein: In the S2, the planetary stirring speed is 2000 rpm, the rotation speed is 800 rpm, and the time is 30 minutes.

4. The process for preparing a silver nanowire conductive film according to claim 1, wherein: The degassing in S2 is carried out by vacuum degassing with a pressure of -0.1 MPa and a time of 5 minutes.

5. A process for preparing a nano silver wire conductive film as claimed in any one of claims 1 to 4, applied to the maintenance of power equipment.

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