Device and method for preparing expanded graphene

Abstract

The invention provides a method for preparing expanded graphene. The method comprises the following steps: introducing argon into a cavity filled with blocky graphite; floating argon above the air, and pressing the air out of an air outlet; closing an air inlet and the air outlet when argon is full of the cavity; controlling a magnetron arranged at the bottom to transmit microwave upward uniformly, repeatedly penetrating the natural blocky graphite by microwave to quickly heat the graphite, and heating and expanding the gas among layers of the graphite; stopping microwave transmission when thegraphite temperature rises to 1000 DEG C; re-controlling the magnetron to transmit microwave when the graphite temperature is reduced to 990 DEG C to heat the blocky graphite to 1000 DEG C, and repeating for several times until the blocky graphite is completely expanded; elongating the upper plate into the groove in the side wall of the cavity by utilizing the extensible upper plate of the upperplate, and leading the cavity to form a closed space; and opening the air outlet, emitting the gas in the cavity, and forming a large pressure difference between the gas pressure among layers of the graphite and the pressure of the cavity to destroy the orderly crystal structure of the graphite structure and form graphene having fewer layers.

Description

technical field [0001] The invention belongs to the technical field of graphene, and in particular relates to a method for preparing graphene by expansion. Background technique [0002] Since graphene was successfully prepared in 2004, it has been favored by people because of its unique structure and properties. Graphene is a carbon material in which carbon atoms are tightly packed into a single-layer two-dimensional honeycomb lattice structure. Its crystal lattice is a hexagonal layered structure, and the layers are connected by van der Waals force. It is because of this structure that it has many peculiar and excellent properties, and these excellent properties make graphene materials attract more and more attention and research. In recent years, with the continuous deepening of research on graphene materials, its application range has been continuously expanded, and it has shown broad application prospects in many fields. [0003] At present, the common methods used to ...

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Problems solved by technology

[0006] In order to solve the shortcomings of the existing graphene preparation method, such as long reaction time, high production cost, high process requirements and poor crystallinity of graphene, the present invention proposes a method for preparing graphene materials in an expanded type: using microwave heating to rapidly and concentrate energy The characteristic is that the natural bulk graphite is treated by microwave radiation, which induces the thermal movement of the graphite internal molecules, causing the gas between the layers to be heated and expanded to generate high pressure, and finally makes the graphite expand rapidly; and then releases the external pressure instantaneously to create an unstable state. The interlayer pressure of graphite is greater than the van der Waals force connecting the layers, destroying the structure between the layers, cracking the graphite flakes and obtaining graphene

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