A method for directly preparing a resistance-controllable graphene film on a resin film

Abstract

The application discloses a method for directly preparing a graphene film with controllable resistance on a resin film, and the specific preparation process steps are as follows: step one, mixing graphene powder, deionized water and an additive to prepare a pretreatment dispersion liquid; step two, adopting a gravure transfer method to coat the pretreatment dispersion liquid prepared in the step one to the surface of a preheated resin film, and forming a graphene coating after drying; and step three, adopting an excimer laser to perform specific area high-temperature composite processing operation on the graphene coating prepared in the step two, and obtaining a resin and graphene composite layer film. The process realizes effective improvement of the preparation efficiency and the yield of the graphene flexible conductive film under the condition of lower energy consumption, and the resistance value can be adjusted through the change of the laser condition.

Description

Technical Field

[0001] This invention relates to a method for directly preparing a graphene film with controllable resistance on a resin film, belonging to the field of materials preparation and application technology. Background Technology

[0002] Flexible all-carbon devices, as post-silicon devices, have attracted much attention due to their flexibility, light weight, and excellent physical and chemical properties, making them widely applicable in fields such as electronic skin, flexible batteries, electronic tags, biosensors, and flexible displays. The substrate materials, transistor channels, electrodes, and dielectric materials of flexible devices all need to possess characteristics such as flexibility, transparency, stretchability, and bendability. Graphene, as a typical representative of low-dimensional nanocarbon materials, possesses excellent electrical, mechanical, optical, and thermal properties, making it an ideal building material for flexible electronic devices.

[0003] The traditional method for fabricating flexible graphene conductive films involves first growing graphene on a rigid substrate using chemical vapor deposition (CVD), then patterning the graphene using photolithography, etching the rigid substrate with acid, and finally transferring the graphene film onto a flexible substrate. This method is technically challenging and complex, resulting in low yield rates. Therefore, it is necessary to develop a simpler process that can directly form graphene conductive films with controllable resistance on flexible substrates. Summary of the Invention

[0004] The existing flexible graphene conductive film fabrication process involves complex graphene transfer, modification, and patterning, requiring high precision. This results in low process controllability and low product yield, severely hindering the industrialization of graphene in flexible devices. To address these issues, this invention provides a method for directly fabricating graphene films with controllable resistance on resin films. The method involves first self-assembling graphene into a film, followed by high-temperature composite processing of specific areas using laser at room temperature and atmospheric pressure to obtain a resin / graphene composite film. This process effectively improves the fabrication efficiency and yield of flexible graphene conductive films with lower energy consumption, and the resistance value can be tuned by varying the laser conditions.

[0005] The technical solution of this invention is: a method for directly preparing a graphene film with controllable resistance on a resin film, the specific preparation process steps of which are as follows:

[0006] Step 1: Prepare a pretreatment dispersion by mixing graphene powder with deionized water and additives;

[0007] Step 2: The pretreated dispersion prepared in Step 1 is coated onto the surface of a preheated resin film using a gravure transfer method, and a graphene coating is formed after drying.

[0008] Step 3: Use an excimer laser to perform high-temperature composite processing on the graphene coating prepared in Step 2 to obtain a resin-graphene composite film.

[0009] Furthermore, the graphene powder sheet diameter mentioned in step one is 5–80 μm.

[0010] Furthermore, the solid content of the pretreated dispersion prepared in step one is 0.5-3%.

[0011] Furthermore, the resin film material mentioned in step two is one of polyethylene terephthalate (PET), polypropylene (PP), or polyethylene (PE).

[0012] Furthermore, the preheated resin film described in step two is heated at a temperature of 60–90°C; the graphene coating formed after drying has a thickness of 5–50 μm.

[0013] Furthermore, in the high-temperature composite processing operation described in step three, the laser wavelength used is 308nm and the pulse energy is 250-500mJ.

[0014] The beneficial effects of the present invention are: the graphene flexible conductive film prepared by the method requires less energy, has a simpler process, and a higher product qualification rate than traditional processes. Its resistance is controllable in a non-vacuum atmosphere, which helps to promote and realize the large-scale production of large-size graphene flexible conductive films.

[0015] A simple process for preparing flexible graphene conductive films at room temperature and atmospheric pressure has been developed. The flexible conductive film is fabricated from graphene and resin composite materials using laser technology. This method can be applied to realize all-carbon devices, such as flexible sensors, energy converters, energy storage devices, and flexible displays.

[0016] The method of this invention can effectively adjust the ratio of resin and graphene melt blending during laser heat treatment of composite materials in a specific area by controlling parameters such as graphene sheet diameter and laser pulse energy, thereby achieving controllable sheet resistance and good mechanical properties of the conductive film. Detailed Implementation

[0017] The present invention will be described in detail below with reference to the embodiments. However, the embodiments are not intended to limit the present invention. Any similar methods or similar variations of the present invention should be included in the protection scope of the present invention.

[0018] Example 1

[0019] Graphene powder with a sheet diameter of 5 μm was mixed with deionized water and additives to prepare a pretreated dispersion with a solid content of 0.5%. The pretreated dispersion was coated onto the surface of a PET film preheated to 60°C using a gravure transfer method. After drying, a graphene coating with a thickness of 5 μm was formed. The graphene coating was subjected to high-temperature composite processing with an excimer laser wavelength of 308 nm and a pulse energy of 250 mJ to obtain a PET / graphene composite film.

[0020] Example 2

[0021] Graphene powder with a sheet diameter of 80 μm was mixed with deionized water and additives to prepare a pretreated dispersion with a solid content of 3%. The pretreated dispersion was coated onto the surface of a PET film preheated to 90°C using a gravure transfer method. After drying, a graphene coating with a thickness of 50 μm was formed. The graphene coating was subjected to high-temperature composite processing with an excimer laser wavelength of 308 nm and a pulse energy of 500 mJ to obtain a PP / graphene composite film.

[0022] Example 3

[0023] Graphene powder with a sheet diameter of 45 μm was mixed with deionized water and additives to prepare a pretreated dispersion with a solid content of 1%. The pretreated dispersion was coated onto the surface of a PET film preheated to 70°C using a gravure transfer method. After drying, a graphene coating with a thickness of 10 μm was formed. The graphene coating was subjected to high-temperature composite processing with an excimer laser wavelength of 308 nm and a pulse energy of 500 mJ to obtain a PE / graphene composite film.

[0024] Based on the parameters of the above embodiments, and after performance testing of the prepared graphene flexible conductive film, the results are as follows:

[0025]

[0026] The results of the above embodiments show that by controlling parameters such as graphene sheet diameter and laser pulse energy, the method of the present invention can effectively adjust the ratio of resin and graphene melt blending during laser heat treatment of composite materials in a specific area, thereby achieving controllable sheet resistance and good mechanical properties of the conductive film.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for directly preparing a resistivity-controllable graphene film on a resin film, characterized in that: The specific preparation process steps are as follows: Step 1: Prepare a pretreatment dispersion by mixing graphene powder with deionized water and additives; Step 2: The pretreated dispersion prepared in Step 1 is coated onto the surface of a preheated resin film using a gravure transfer method, and a graphene coating is formed after drying. Step 3: Use an excimer laser to perform high-temperature composite processing on the graphene coating prepared in Step 2 to obtain a resin-graphene composite film. In the high-temperature composite processing operation described in step three, the laser wavelength used is 308nm and the pulse energy is 250-500mJ; during the laser heat treatment process, the resin and graphene are melt-blended.

2. The method for directly preparing a resistivity-controllable graphene film on a resin film according to claim 1, characterized in that: The graphene powder sheet diameter mentioned in step one is 5-80 μm.

3. The method for directly preparing a resistivity-controllable graphene film on a resin film according to claim 1, characterized in that: The pretreated dispersion prepared in step one has a solid content of 0.5-3%.

4. The method for directly preparing a resistivity-controllable graphene film on a resin film according to claim 1, characterized in that: The resin film material mentioned in step two is one of polyethylene terephthalate, polypropylene, or polyethylene.

5. The method for directly preparing a resistivity-controllable graphene film on a resin film according to claim 1, characterized in that: The preheated resin film described in step two is heated at a temperature of 60–90°C; the graphene coating formed after drying has a thickness of 5–50 μm.

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