Preparation method of PPy-GNS-CNT-PVA conductive film

Abstract

The application relates to the technical field of conductive film preparation, and discloses a preparation method of a PPy-GNS-CNT-PVA conductive film, which comprises the following steps: step 1, preparing a graphene and carbon nanotube dispersion solution by adopting sodium dodecyl sulfate; step 2, adding polyvinylpyrrolidone into the graphene and carbon nanotube dispersion solution, carrying out magnetic stirring after ultrasonic treatment, then adding distilled pyrrole monomers, and stirring FeCl3 solution to prepare ink; step 3, heating the ink in water bath stirring, then adding PVA powder and continuing to stir to prepare a film pre-coating material; and step 4, directly coating the film pre-coating material into a film to prepare the PPy-GNS-CNT-PVA conductive film. In the application, in-situ emulsion polymerization of pyrrole and PVA as a filling main body of conductive fillers are adopted, and graphene and carbon nanotubes are compounded, so that the obtained film has better conductivity and mechanical performance and better biocompatibility.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of preparation of conductive films, and more particularly relates to a preparation method of a PPy-GNS-CNT-PVA conductive film. BACKGROUND

[0002] Indium tin oxide (ITO) is widely used in the thin film market such as touch screens and solar panels due to its high light transmittance and high conductivity, but because of the scarcity of indium and its inherent brittleness, and because the preparation method is mostly magnetron sputtering, the deposition process is complex, the environmental requirements are high, the cost is large, and it is fundamentally impossible to meet the requirements of modern flexible electronic new materials, so we urgently need to find a substitute material for ITO in the flexible electronic industry.

[0003] Graphene, a special material with a two-dimensional network, has excellent conductivity, light transmittance and mechanical properties, and is widely studied as an ideal ITO substitute, and its source is graphite, and the yield of graphene prepared by the oxidation-reduction method is large and the cost is low, so it is one of the main materials for flexible electronic devices.

[0004] As a typical conductive polymer, polypyrrole (PPy) has the advantages of low cost, simple synthesis, low density, good conductivity, good biocompatibility, etc., and is currently widely used in different fields such as supercapacitors, solar cells, energy storage devices, biosensing, etc., and the composite material of graphene and polypyrrole is more likely to form a conductive filler with excellent conductivity, and the introduction of graphene into the polymer matrix can significantly improve the mechanical and electrical properties of the polymer matrix. However, the conductivity of polypyrrole alone does not meet the requirements of flexible electronics, and it is not soluble in water or organic matter, making it difficult to use. Even if the material has good mechanical properties, it is difficult to meet the requirements of most materials. SUMMARY

[0005] In view of this, in order to achieve the above-mentioned purpose, the application provides a preparation method of a PPy-GNS-CNT-PVA conductive film, which forms an integral whole by attaching polypyrrole nanoparticles to the surface of graphene sheets and graphene, improves the biocompatibility of the composite material, and the conductivity after doping cannot be ignored for the conductive performance of the film. As a conductive bridge between graphene sheets, carbon nanotubes supplement the conductive network, and when filled into polyvinyl alcohol, the conductive performance, mechanical properties and degradability of the material are very promising in the field of flexible wearable electronics.

[0006] In order to achieve the above-mentioned purpose, the application is realized by the following technical scheme: a preparation method of a PPy-GNS-CNT-PVA conductive film, comprising the following steps:

[0007] Step 1: prepare a graphene and carbon nanotube dispersion solution using sodium dodecyl sulfate (SDS);

[0008] Step 2: adding polyvinylpyrrolidone (PVP) into the graphene and carbon nanotube dispersion liquid, carrying out magnetic stirring after ultrasonic treatment, then adding distilled pyrrole monomer, and stirring after adding FeCl3 solution to prepare the ink;

[0009] The mass ratio of the polyvinylpyrrolidone and sodium dodecyl sulfate is 1:0.3-1.2; the ratio of the adding amount of the polyvinylpyrrolidone and the pyrrole monomer is 2g:3-5mL; the K value of the polyvinylpyrrolidone is 30;

[0010] Step 3: heating the ink in water bath stirring, then continuously stirring after adding PVA powder to prepare the film pre-coating material;

[0011] Step 4: directly coating the film pre-coating material into a film to prepare the PPy-GNS-CNT-PVA conductive film.

[0012] The preparation principle of the application is that: in step 1, SDS is used as a surface modifier of graphene and carbon nanotube for dispersing graphene and carbon nanotube, and the amphiphilic property of SDS makes pyrrole polymerize to form nanoparticles attached to the surface of graphene sheet, so that the contact area between graphene and graphene and between graphene and polypyrrole is increased, the formation of polymer conductive network is promoted, the percolation threshold is reduced, and the anionic structure of SDS also acts as a dopant of polypyrrole to improve the conductivity of polypyrrole. In step 2, an appropriate amount of PVP is added as a dispersant of polypyrrole to make the pyrrole monomer in-situ emulsion polymerization in the PVP solution package, and because the larger the molecular weight of PVP is, the smaller the molecular weight of the polypyrrole formed by polymerization is, in order to disperse uniformly and make the polypyrrole uniformly dispersed on the surface of the graphene sheet, we use PVP with a K value of 30, because experiments prove that PVP with a larger K value is easy to cause the graphene, carbon nanotube and other substances to agglomerate in this step of adding pyrrole monomer, forming a substance similar to gel, which is not conducive to the occurrence of polymerization. Moreover, it can be used as a modifier of PVA to make the mechanical properties of PVA better through the interaction of hydrogen bonds.

[0013] Further preferably, step 1 is specifically: mixing graphene, carbon nanotube and sodium dodecyl sulfate, stirring with water for 10-20min, then using a cell crusher to oscillate for 30-40min, and taking the supernatant by centrifugation.

[0014] Further preferably, the mass ratio of the graphene and carbon nanotube is 1:7; and the mass ratio of the total mass of the graphene and carbon nanotube to the sodium dodecyl sulfate is 1:8-12.

[0015] The formed point network has the best performance when the mass ratio of graphene to carbon nanotube is 1:7, the carbon nanotube can be used as a conductive connecting bridge between graphene layers, so that the overall amount of carbon material is reduced, and the conductive performance is better.

[0016] Further preferably, the mass ratio of the total mass of graphene and carbon nanotube to the mass of water is 1:100-200.

[0017] Further preferably, the centrifugation time is 10-15 min, and the speed is 7000-9000 rpm.

[0018] Further preferably, in step 2, the concentration of the FeCl3 solution is 0.8-1.5 mol / L.

[0019] Further preferably, in step 2, the ultrasonic time is 20-40 min.

[0020] Further preferably, in step 3, the heating temperature is 75-90℃; the mass ratio of the PVA powder to the water in step 1 is 1:12-18; and the continuous stirring time is 2-4 h.

[0021] Further preferably, in step 4, the coating is spin coating or rod coating.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] (1) The present application uses in-situ emulsion polymerization of pyrrole, so that the poly-pyrrole and graphene composite material is more uniformly dispersed, the composite is more uniform, and the conductivity is better;

[0024] (2) The present application uses PVA as the filling main body of the conductive filler, which has extremely high bending deformation and fracture resistance to static pressure, so the film has excellent mechanical properties, and its degradation is also very good, which is more friendly to the environment;

[0025] (3) The graphene and poly-pyrrole composite material used in the present application makes the film have good conductivity and very good biocompatibility, and has more prospects for use in wearable flexible electronics industry;

[0026] (4) In the present application, SDS is used as a surface modifier of graphene and carbon nanotube, and also as a dopant of poly-pyrrole, which improves the conductivity of poly-pyrrole and reduces impurities in the film, and the performance is more excellent;

[0027] (5) PVP in the present application is a surface modifier of poly-pyrrole, which makes pyrrole polymerization dispersed uniformly as an emulsifier for emulsion polymerization, and is also a modifier of PVA, which reduces the use of materials, makes the experiment more convenient and fast, and has lower cost. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Infrared spectrum of PPy-GNS-CNT-PVA conductive film in the present application. DETAILED DESCRIPTION

[0029] The technical content and effects of the present application will be further described in detail below in combination with examples, but the present application is not limited thereby.

[0030] Example 1

[0031] Step 1: measure 20ml of deionized water into a beaker, add graphene 0.025g, single-walled carbon nanotube 0.175g, SDS 2g, then use a magnetic stirrer to stir for 15min, and then use a cell crusher to crush for 30min. Then centrifuge at 8000rpm for 10min, take 80% of the supernatant into a beaker, and prepare a graphene and carbon nanotube dispersion.

[0032] Step 2: add 2g of PVP powder with K value of 30 to the graphene and carbon nanotube dispersion and ultrasonic for 30min, then place it on a magnetic stirrer and stir, add 3mL of distilled pyrrole monomer, stir for 3min, then add 1mol / L FeCl3 solution, stir for 24h, and prepare the ink.

[0033] Step 3: water bath heating of the ink, stirring while heating to 85℃, then adding 1.5g of PVA powder, stirring for 3h, and preparing the film pre-coating material.

[0034] Step 4: the film pre-coating material is coated into a film by rod coating method with a thickness of 1mm, and PPy-GNS-CNT-PVA conductive film is prepared.

[0035] Example 2

[0036] Step 1: measure 20ml of deionized water into a beaker, add graphene 0.025g, single-walled carbon nanotube 0.175g, SDS 1.6g, then use a magnetic stirrer to stir for 15min, and then use a cell crusher to crush for 30min. Then centrifuge at 8000rpm for 10min, take 80% of the supernatant into a beaker, and prepare a graphene and carbon nanotube dispersion.

[0037] Step 2: add 2g of PVP powder with K value of 30 to the graphene and carbon nanotube dispersion and ultrasonic for 30min, then place it on a magnetic stirrer and stir, add 3mL of distilled pyrrole monomer, stir for 3min, then add 1mol / L FeCl3 solution, stir for 24h, and prepare the ink.

[0038] Step 3: The ink is heated in a water bath, heated to 85°C while stirring, and then 1.5 g of PVA powder is added and stirred for 3 h to obtain a film pre-coating material.

[0039] Step 4: The film pre-coating material is coated into a film with a thickness of 1 mm by rod coating to obtain a PPy-GNS-CNT-PVA conductive film.

[0040] Example 3

[0041] Step 1: 20 ml of deionized water is placed in a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2.4 g of SDS are added, and then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant is taken and placed in a beaker to obtain a graphene and carbon nanotube dispersion.

[0042] Step 2: 2 g of PVP powder with a K value of 30 is added to the graphene and carbon nanotube dispersion and ultrasonically treated for 30 min, and then stirred on a magnetic stirrer, 3 mL of distilled pyrrole monomer is added, stirred for 3 min, and then 1 mol / L FeCl3 solution is added and stirred for 24 h to obtain an ink.

[0043] Step 3: The ink is heated in a water bath, heated to 85°C while stirring, and then 1.5 g of PVA powder is added and stirred for 3 h to obtain a film pre-coating material.

[0044] Step 4: The film pre-coating material is coated into a film with a thickness of 1 mm by rod coating to obtain a PPy-GNS-CNT-PVA conductive film.

[0045] Example 4

[0046] Step 1: 20 ml of deionized water is placed in a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2 g of SDS are added, and then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant is taken and placed in a beaker to obtain a graphene and carbon nanotube dispersion.

[0047] Step 2: 2.4 g of PVP powder with a K value of 30 is added to the graphene and carbon nanotube dispersion and ultrasonically treated for 30 min, and then stirred on a magnetic stirrer, 3 mL of distilled pyrrole monomer is added, stirred for 3 min, and then 1 mol / L FeCl3 solution is added and stirred for 24 h to obtain an ink.

[0048] Step 3: The ink is heated in a water bath, heated to 85°C while stirring, and then 1.5 g of PVA powder is added and stirred for 3 h to obtain a film pre-coating material.

[0049] Step 4: The film pre-coating material is coated into a film with a thickness of 1 mm by a bar coating method to obtain a PPy-GNS-CNT-PVA conductive film.

[0050] Comparative Example 1

[0051] Step 1: 20 ml of deionized water is placed in a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2 g of SDS are added, then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant is taken and placed in a beaker to obtain a graphene and carbon nanotube dispersion.

[0052] Step 2: 3 mL of distilled pyrrole monomer is added to the graphene and carbon nanotube dispersion, stirred on a magnetic stirrer, and then 2 g of PVP powder with a K value of 30 is added and ultrasonically treated for 30 min. After stirring for 3 min, 1 mol / L FeCl3 solution is added and stirred for 24 h to obtain an ink.

[0053] Step 3: The ink is heated in a water bath, heated to 85°C while stirring, and then 1.5 g of PVA powder is added and stirred for 3 h to obtain a film pre-coating material.

[0054] Step 4: The film pre-coating material is coated into a film with a thickness of 1 mm by a bar coating method to obtain a PPy-GNS-CNT-PVA conductive film.

[0055] Comparative Example 2

[0056] Step 1: 20 ml of deionized water is placed in a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2 g of SDS are added, then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant is taken and placed in a beaker to obtain a graphene and carbon nanotube dispersion.

[0057] Step 2: 1.5 g of PVP powder with a K value of 30 is added to the graphene and carbon nanotube dispersion and ultrasonically treated for 30 min, then stirred on a magnetic stirrer, and then 3 mL of distilled pyrrole monomer is added. After stirring for 3 min, 1 mol / L FeCl3 solution is added and stirred for 24 h to obtain an ink.

[0058] Step 3: The ink was heated in a water bath, heated to 85°C while stirring, and then 1.5 g of PVA powder was added and stirred for 3 h to obtain a film pre-coating material.

[0059] Step 4: The film pre-coating material was coated into a film with a thickness of 1 mm by a bar coating method to obtain a PPy-GNS-CNT-PVA conductive film.

[0060] Comparative Example 3

[0061] Step 1: 20 ml of deionized water was measured into a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2 g of SDS were added, then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant was taken into a beaker to obtain a graphene and carbon nanotube dispersion.

[0062] Step 2: 2 g of PVP powder with a K value of 30 was added to the graphene and carbon nanotube dispersion and ultrasonicated for 30 min, then placed on a magnetic stirrer and stirred, 3 mL of distilled pyrrole monomer was added, stirred for 3 min, then 1 mol / L FeCl3 solution was added, and stirred for 24 h to obtain an ink.

[0063] Step 3: The ink was heated in a water bath, heated to 85°C while stirring, and then 1.0 g of PVA powder was added and stirred for 3 h to obtain a film pre-coating material.

[0064] Step 4: The film pre-coating material was coated into a film with a thickness of 1 mm by a bar coating method to obtain a PPy-GNS-CNT-PVA conductive film.

[0065] Comparative Example 4

[0066] Step 1: 30 ml of deionized water was measured into a beaker, 0.025 g of graphene, 0.175 g of single-walled carbon nanotubes, and 2 g of SDS were added, then stirred for 15 min using a magnetic stirrer, and then crushed for 30 min using a cell crusher. Then centrifuged at 8000 rpm for 10 min, and 80% of the supernatant was taken into a beaker to obtain a graphene and carbon nanotube dispersion.

[0067] Step 2: 2 g of PVP powder with a K value of 30 was added to the graphene and carbon nanotube dispersion and ultrasonicated for 30 min, then placed on a magnetic stirrer and stirred, 3 mL of distilled pyrrole monomer was added, stirred for 3 min, then 1 mol / L FeCl3 solution was added, and stirred for 24 h to obtain an ink.

[0068] Step 3: Heat the ink in a water bath while stirring until it reaches 85°C. Then add 2g of PVA powder and stir for 3 hours to obtain the film pre-coating material.

[0069] Step 4: Apply the pre-coating material to the film using a rod coating method to form a 1mm thick PPy-GNS-CNT-PVA conductive film.

[0070] Table 1

[0071]

[0072]

[0073] like Figure 1 As shown, 3438cm -1 The peaks are characteristic of polypyrrole, confirming the effectiveness of this method for pyrrole polymerization.

[0074] Comparing the data in Table 1, it can be seen that in Comparative Example 1, changing only the experimental steps leads to a significant decrease in fracture strength and electrical conductivity. In Comparative Example 2, the amount of PVP added was outside the acceptable range, and in Comparative Examples 3 and 4, the amount of PVA added was also outside the acceptable range, ultimately resulting in fracture strength or electrical conductivity not reaching the optimal effect.

[0075] Changing the SDS content does not significantly alter the mechanical strength and conductivity of the film. However, changing the PVA content, which is equivalent to altering the graphene-carbon nanotube ratio, can significantly change the film's mechanical properties and conductivity. Reducing the PVA content results in excessive conductive filler filling, leading to poorer mechanical properties but improved conductivity. A moderate increase in PVP can enhance the film's mechanical properties, but excessive amounts will negatively impact its conductivity.

[0076] The above embodiments of the present invention are merely illustrative examples and are not intended to limit the implementation of the invention. Those skilled in the art can make other variations and modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a PPy-GNS-CNT-PVA conductive thin film, characterized in that, Includes the following steps: Step 1: Mix graphene, carbon nanotubes and sodium dodecyl sulfate. The mass ratio of graphene to carbon nanotubes is 1:7, and the mass ratio of the total mass of graphene and carbon nanotubes to sodium dodecyl sulfate is 1:8-12. Add water and stir for 10-20 minutes. The mass ratio of the total mass of graphene and carbon nanotubes to water is 1:100-200. Then, use a cell disruptor to shake for 30-40 minutes. Centrifuge and collect the supernatant to obtain a dispersion of graphene and carbon nanotubes. Step 2: Polyvinylpyrrolidone (PVP) with a K value of 30 is added to the graphene and carbon nanotube dispersion. The mass ratio of PPVP to sodium dodecyl sulfate is 1:0.3-1.2, and the ratio of PPVP to pyrrole monomer is 2g:3-5mL. After ultrasonic treatment, the mixture is magnetically stirred, then distilled pyrrole monomer is added, followed by FeCl3 solution and stirring to obtain the ink. Step 3: Heat and stir the ink in a water bath, then add PVA powder and continue stirring. The mass ratio of PVA powder to water in Step 1 is 1:12-18 to obtain the film pre-coating material. Step 4: Directly coat the pre-coated material to form a film, thus obtaining a PPy-GNS-CNT-PVA conductive film.

2. The method for preparing the PPy-GNS-CNT-PVA conductive film as described in claim 1, characterized in that, The centrifugation time is 10-15 min, and the speed is 7000-9000 rpm.

3. The method for preparing the PPy-GNS-CNT-PVA conductive film as described in claim 1, characterized in that, In step 2, the concentration of the FeCl3 solution is 0.8-1.5 mol / L.

4. The method for preparing the PPy-GNS-CNT-PVA conductive film as described in claim 1 or 3, characterized in that, The ultrasound time in step 2 is 20-40 minutes.

5. The method for preparing the PPy-GNS-CNT-PVA conductive film as described in claim 1, characterized in that, In step 3, the heating temperature is 75-90 ℃; the stirring time is 2-4 h.

6. The method for preparing the PPy-GNS-CNT-PVA conductive film as described in claim 1, characterized in that, In step 4, the coating is applied by spin coating or bar coating.

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