Preparation method of composite heat conduction graphene film and composite heat conduction graphene film

Abstract

The invention discloses a preparation method of a composite heat conduction graphene membrane and the composite heat conduction graphene film. The preparation method comprises the following steps: S1, putting crystalline flake graphite or graphite powder into a mixed solution of concentrated sulfuric acid, potassium persulfate and phosphorus pentoxide, soaking for a day and a night, then carrying out suction filtration, drying, and carrying out pre-oxidizing; S2, oxidizing pre-oxidized graphite further by adopting a Hummers method, that is, oxidizing fully in concentrated sulfuric acid and potassium permanganate, then adding deionized water for diluting, and carrying out repeated washing and suction filtration, so as to obtain an oxidized graphene aqueous solution; S3, spraying the oxidized graphene aqueous solution on a substrate by adopting a thermal spray method, and depositing, so as to obtain an oxidized graphene film; S4, reducing the oxidized graphene film, so as to obtain the graphene film; and S5, laminating the graphene film, so as to obtain the composite heat conduction graphene film. Compared with the prior art, the preparation method is simple, the cost is low, and the prepared composite heat conduction graphene film has a favorable heat conduction performance.

Description

technical field [0001] The invention relates to a preparation method and product of a graphene composite heat conduction film, in particular to a preparation method and product of a graphene composite heat conduction film used in the fields of electronic information product heat dissipation devices, chip overheat protection, heat conduction interface materials, etc., belonging to Technical field of electronic functional materials. Background technique [0002] For electronic products, the effective heat dissipation of its various components to obtain a lower operating temperature will have an extremely important impact on its service life and operating speed. With the continuous development and progress of science and technology, especially the multi-core of computer chips has become the mainstream, and the running speed continues to increase, and the power also increases accordingly. Effective heat dissipation plays a decisive role in its running speed. At present, the mai...

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Problems solved by technology

Coating methods include pulling, spin coating, doctor blade, etc. The difficulty is how to configure a stable and non-agglomerated graphene slurry, which requires adding thickeners, surfactants, and binders to the slurry Additives such as additives, but these additives will make graphene or graphene oxide not well connected together; and due to the steric hindrance of the additives, it is impossible to make graphene layer by layer parallel to the substrate in an orderly manner. Connecting together will greatly reduce the thermal conductivity of the heat dissipation film; in addition, the spin coating method is not suitable for preparing large-area films, and the suction filtration method is time-consuming and difficult to control the film thickness

The cost of preparing thermal conductive film by CVD method is relatively high. Generally, graphene grows one or more layers of graphene on the substrate by CVD method. It is relatively difficult to form a thick graphene layer, generally hundreds of nanometers thick, so it is not suitable for the preparation of heat dissipation film. film, but mainly used for conductive film; at the same time, the CVD preparation of thermally conductive film also faces a problem of transfer, which must be transferred from the metal substrate to the required substrate to use the processing device, and the transfer will bring more heat to the thermally conductive film. Defects

[0004] In addition to the above-mentioned methods, methods such as LB (Langmuir-Blodgett) membrane method, solution casting, and casting methods are often used in the laboratory to prepare graphene films, but these laboratory methods are complicated in technology and expensive in price, and are not suitable for graphene films. large-scale industrial production

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