Method for making graphene be horizontally spread to self assemble and form graphene membrane

Abstract

The invention discloses a method for making graphene be horizontally spread to self assemble and form a graphene membrane. The method comprises the steps: adding methylbenzene and ethyl alcohol into agraphene water solution according to proportion, evenly mixing and pouring the mixture into a vacuum suction filtration device; the graphene is limited at the interface when a solution in a suction filtration bottle forms an upper-lower layered solution system, the graphene is horizontally spread at the interface under the shearing force action, the (002) plane of the graphene tends to be parallel to the interface, the graphene can generate self assembling to form the graphene membrane, the suction filtration device is started to pump out the solution, and the graphene membrane with the (002)plane thereof being mutually parallel on the micro level can be obtained on filter paper. The method has the advantages of simple technology and low reagent and equipment cost; no raw material wasteis generated in a membrane preparation process, and the yield is 100%; the graphene is directly utilized, so that follow-up reduction reaction required by utilizing oxidized graphene is avoided, and product quality is good; the whole production cycle is only several minutes, and the production efficiency is high; the method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of preparation of new energy materials, and relates to a method for horizontally tiling and self-assembling graphene to form a graphene film. Background technique [0002] Due to its outstanding physical and chemical properties and unique two-dimensional structure of a single atomic layer, graphene is widely used in research fields such as transparent conductive films, electromagnetic shielding films, and heat conduction and heat dissipation films. Chen's research group prepared rGO thin films by spin coating combined with thermal reduction, which can be used as conductive transparent electrodes [ACS Nano, 2008, 2:463-470]. Mullen's research group assembled GO onto a quartz wafer by dip-coating and thermally reduced it to obtain a rGO film that can be used as a transparent conductive electrode [NanoLett, 2008, 8:323-327]. Zheng's group used the method of volatilization-induced self-assembly combined with hi...

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Problems solved by technology

[0015] Although the above method can realize large-scale preparation of graphene, there are also unavoidable problems

The vacuum filtration method is simple and efficient, but the existing vacuum filtration method can only make the graphene horizontally oriented, but cannot control the orientation of the graphene (002) plane, that is, it cannot make the graphene spread horizontally as much as possible, so the suction filtration Although the obtained graphene film has a layered structure at the micron scale, its basic unit graphene will produce many wrinkles due to the forced compression of the external force at the nanoscale. The existence of wrinkles greatly increases the internal voids and specific surface area of ​​the graphene film. , which increases the contact resistance between sheets and the scattering of phonons, which eventually leads to the loss of electrical and thermal conductivity; large-area graphene films can be prepared by spray coating and suspension coating, but the microstructure of graphene films is disordered. The irregular stacking of the basic graphene causes a large contact resistance and phonon scattering, resulting in poor electrical and thermal conductivity of the graphene film; the electrophoresis method is simple to operate, easy to control, low in cost, and suitable for large-scale preparation. The prepared film is relatively uniform, but its basic element graphene is freely oriented, and many graphene edges are exposed on the surface of the graphene film, indicating that there is a large contact resistance and phonon scattering between the sheets. After the film is formed, there will be a lot of inconvenience when transferring the film from the electrode; the self-assembly method is simple and easy, and the graphene oxide can be flattened into a film on the liquid surface, and the (002) planes of the graphene oxide are parallel to each other, and the obtained The graphene oxide film exhibits good uniformity and controllability, but since graphene oxide is used as an intermediate, the subsequent complex reduction treatment will destroy the original tiling microstructure, resulting in the loss of electrical and thermal conductivity.

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