CN-116854081-B - Preparation method of graphene heat conduction film

CN116854081BCN 116854081 BCN116854081 BCN 116854081BCN-116854081-B

Abstract

The invention provides a preparation method of a graphene heat-conducting film, which comprises the steps of A) mixing graphene oxide, a solvent, a dispersing aid and a connecting aid to obtain slurry, B) coating the slurry on a base material, drying the slurry to form a film, separating the film from the base material to obtain a graphene oxide film, C) carbonizing the graphene oxide film under a protective atmosphere, D) graphitizing the film obtained in the step C) under the protective atmosphere, and E) pressing the film obtained in the step D) to obtain the graphene heat-conducting film. The preparation method provided by the invention can reduce cracking and surface roughness phenomena in the drying film forming process, improve defects and edge disorder existing in graphene, and improve the thermal conductivity of the graphene heat conducting film.

Inventors

ZHANG XUEAO
CAO YANG
WU BINGHUI
ZHANG JIE
ZHU ZHANBO
HAN XUEPENG

Assignees

嘉庚创新实验室

Dates

Publication Date: 20260505
Application Date: 20230718

Claims (6)

1. The preparation method of the graphene heat conduction film is characterized by comprising the following steps of: a) Mixing graphene oxide, a solvent, a dispersing auxiliary and a connecting auxiliary, homogenizing and defoaming to obtain slurry; The dispersing aid is at least one of ethanolamine and organic silicon resin, wherein the organic silicon resin is amine functional siloxane resin, and the amine functional siloxane resin is at least one of 3-aminopropyl methyl dimethyl siloxane and (3-aminopropyl) dimethyl methoxy silane; The consumption of the dispersing auxiliary is 5% -50% of the mass of the graphene oxide; the consumption of the connection auxiliary agent is 0.1% -0.5% of the mass of the graphene oxide; The dosage relation of the graphene oxide and the solvent is that the solid content of the graphene oxide in the solvent is 2-5wt%; b) Coating the slurry on a substrate, drying the slurry to form a film, and separating the film from the substrate to obtain a graphene oxide film; C) Carbonizing the graphene oxide film in a protective atmosphere; the heating rate of the carbonization treatment is 5-50 ℃ per minute, and the heat preservation time is 1-5 hours; D) Graphitizing the film obtained in the step C) in a protective atmosphere; The temperature rising rate of the graphitization treatment is 5-10 ℃ per minute, and the heat preservation time is 3-5 hours; e) Pressing the film obtained in the step D) to obtain a graphene heat conducting film; The pressure of the pressing treatment is 30-80 MPa, and the pressure maintaining time is 30-300 min.
2. The method according to claim 1, wherein in step a), the connection aid is boric acid and/or titanium diboride.
3. The method according to claim 1, wherein in the step C), the carbonization treatment is performed at a temperature of 800 to 1500 ℃.
4. The method according to claim 1, wherein in the step D), the graphitization treatment is performed at a temperature of 2600 to 3100 ℃.
5. The method according to claim 1, wherein in step B): The thickness of the coating is 3-7 mm; The drying temperature is 30-80 ℃.
6. The method according to claim 1, wherein in step a), the solvent is at least one selected from the group consisting of water, ethanol and N, N-dimethylformamide.

Description

Preparation method of graphene heat conduction film Technical Field The invention relates to the field of heat conducting films, in particular to a preparation method of a graphene heat conducting film. Background In the existing heat conduction material, graphene is a planar two-dimensional layered material with hexagonal lattice formed by carbon atoms in sp 2 hybridized orbits, has excellent physical and chemical properties, and has a theoretical heat conduction coefficient as high as 5300W/(m.K). Compared with the traditional heat conduction materials (graphite, aluminum, copper and the like), the heat conduction material has high heat conduction and light weight, and is one of ideal heat conduction materials. At present, graphite oxide is mainly used for preparing a graphene heat conduction film, namely graphite oxide is dispersed in a solvent to form graphene oxide slurry, the graphene oxide slurry is coated on a substrate in a blade coating mode, then the graphene oxide film is formed by drying, and then the graphene oxide film is subjected to chemical reduction or thermal reduction to obtain the graphene heat conduction film. In the graphene heat-conducting film preparation process, the viscosity of graphene oxide slurry is increased along with the increase of the solid content and the increase of the standing time, the phenomenon of film forming cracking, surface roughness and the like occurs in the process of forming the graphene oxide film by drying the graphene oxide slurry due to the fact that the viscosity is high, so that the heat conductivity of the obtained graphene heat-conducting film is reduced, meanwhile, the heat conductivity of graphene is closely related to the size of a lamellar layer, the stacking degree of the lamellar layer, the defects of the lamellar layer and the like, and the sp 2 hybridized carbon extension network of the graphene oxide is damaged due to the fact that the graphene oxide is rich in oxygen-containing functional groups in the surface and the edges, and the graphene oxide needs to be reduced at high temperature to remove the functional groups so as to recover a graphitized structure, but defects of the graphene and disorder of the edges are caused, so that the heat conductivity of the graphene is reduced. Disclosure of Invention In view of the above, the invention provides a preparation method of a graphene heat conducting film. The preparation method provided by the invention can reduce cracking and surface roughness phenomena in the drying film forming process, improve defects and edge disorder existing in graphene, and improve the thermal conductivity of the graphene heat conducting film. The invention provides a preparation method of a graphene heat conduction film, which comprises the following steps: a) Mixing graphene oxide, a solvent, a dispersing aid and a connecting aid to obtain slurry; b) Coating the slurry on a substrate, drying the slurry to form a film, and separating the film from the substrate to obtain a graphene oxide film; C) Carbonizing the graphene oxide film in a protective atmosphere; D) Graphitizing the film obtained in the step C) in a protective atmosphere; E) And D) performing pressing treatment on the film obtained in the step D) to obtain the graphene heat conducting film. Preferably, in the step A), the dispersing aid is at least one of ethanolamine, AMP-95 and silicone resin. Preferably, in the step A), the connection auxiliary agent is boric acid and/or titanium diboride. Preferably, in the step a), the amount of the dispersing aid is preferably 5% -50% of the mass of the graphene oxide. Preferably, in the step A), the dosage of the connection auxiliary agent is 0.1% -0.5% of the mass of the graphene oxide. Preferably, in the step C), the carbonization treatment is performed at 800-1500 ℃ for 1-5 hours. Preferably, in the step D), the graphitization treatment is performed at a temperature of 2600-3100 ℃ for 3-5 hours. Preferably, in the step E), the pressure of the pressing treatment is 30-80 MPa, and the pressure maintaining time is 30-300 min. Preferably, in step B): the thickness of the coating is 3-7 mm; The drying temperature is 30-80 ℃. Preferably, in step a), the solvent is selected from at least one of water, ethanol and N, N-dimethylformamide; The dosage relation of the graphene oxide and the solvent is that the solid content of the graphene oxide in the solvent is 2-5wt%. The preparation method of the graphene heat-conducting film comprises the steps of mixing graphene oxide, a solvent, a dispersing aid and a connecting aid to obtain slurry, coating the slurry on a base material, drying to form a film, performing a series of heat treatments on the film, including carbonization treatment and graphitization treatment, and finally pressing to obtain the graphene heat-conducting film. The preparation method comprises the steps of preparing a slurry, wherein a specific dispersing auxiliary agent and a connecting auxiliary age