Graphene (Graphene) is a two-dimensional crystal separated from graphite and composed of carbon atoms with only one layer of atomic thickness. It is the thinnest and strongest material in nature at present, and its fracture strength is 200 times higher than that of the best steel. At the same time, it has good elasticity, and the tensile range can reach 20% of its own size. However, graphene is difficult to produce a certain product as a single raw material, and mainly uses its outstanding properties to composite with other material systems, so as to obtain a new type of composite materials with excellent properties.
Structure of graphene composites.
Graphene-loaded composites: composites obtained by introducing a second component on the surface of graphene and epitaxial extension on its surface.
Graphene-coated composites: composites wrapped in the second component with graphene sheets can more effectively prevent the polymerization of the second component.
Graphene embedded composites: composites obtained by fully dispersing graphene nanoparticles as fillers in the matrix phase of the second component. Among them, the matrix phase can be either nanomaterials or bulk materials.
Graphene-based layered composites: the second component and graphene sheets are stacked alternately, which can maximize the contact area between graphene and the second component, and is conducive to the generation, transport and separation of electrons.
Classification of graphene matrix composites.
Graphene has many excellent properties, such as good electrical conductivity, good toughness, large specific surface area and so on. These properties make graphene matrix composites show many excellent properties. If graphene is used as the carrier to load nanoparticles, the catalytic performance and conductivity of these particles can be improved; the mechanical properties and electrical conductivity of polymer materials can be improved by adding graphene to polymer with good toughness. According to the difference of the second component, graphene composites can be divided into graphene-nanoparticles composites, graphene-polymer composites and graphene-carbon matrix composites.
The unique physical and chemical properties of nanoparticles have aroused great interest of nanoscientists, but finding suitable carriers has become a difficult problem in the wide application of nanoparticles. Compared with other carbon materials (carbon nanotubes, fullerenes, etc.), graphene has excellent electrical, optical and other physical and chemical properties, as well as low preparation cost, making graphene a potential carrier of nanoparticles. Due to the effect of interlamellar van der Waals force, graphene often has irreversible agglomeration, and the nanoparticles existing in graphene interlayer play a role in separating adjacent graphene lamellae and preventing agglomeration. In recent years, graphene has been creatively combined with nanoparticles to form a new research field.
There have been many reports on carbon-based materials-polymer composites, especially based on carbon nanowires, carbon nanotubes and fullerene-polymer composites, as a unique member of the carbon material family. Graphene can also be used as an additive or carrier to composite with polymers. Graphene has great application value in improving the thermal, mechanical and electrical properties of polymers because of its unique structure and properties.
Graphene-carbon matrix composites.
Graphene can not only be combined with nanoparticles and polymers, but also can be assembled with other carbon-based materials (carbon nanotubes, fullerenes, etc.) to form composites. These carbon-based materials can combine with each other and show some excellent properties.