(2) Application fields:
Adding 1% graphene to plastics can make plastics have good conductivity; Adding one thousandth of graphene can improve the heat resistance of plastics at 30 degrees Celsius. On this basis, new materials with thin, light weight, good ductility and super toughness can be developed for manufacturing automobiles, airplanes and satellites.
With the gradual breakthrough of mass production and large-size problems, the pace of industrial application of graphene is accelerating. Based on the existing research results, the first commercial applications may be mobile devices, aerospace and new energy batteries.
Flexible screens have attracted much attention at the Consumer Electronics Show, and become the development trend of mobile device displays in the future.
On the other hand, new energy batteries are also an important field for the earliest commercialization of graphene.
Due to the characteristics of high conductivity, high strength and ultra-thin, the application advantages of graphene in aerospace military industry are also extremely prominent. Graphene will also play a more important role in potential applications such as ultra-light aircraft materials.
1, electronic transportation:
Before the discovery of graphene, most (if not all) physicists thought that thermodynamic fluctuations did not allow any two-dimensional crystal to exist at a finite temperature. Therefore, its discovery immediately shocked the condensed matter physics community. Although both theoretical and experimental circles believe that the perfect two-dimensional structure can not exist stably at non-absolute zero, single-layer graphene was prepared in the experiment. These may be attributed to the microscopic distortion of graphene at the nanometer level.
2. Conductivity:
The structure of graphene is very stable. So far, researchers have not found that graphene lacks any carbon atoms. The connection between carbon atoms in graphene is very flexible. When mechanical external force is applied, the surface of carbon atoms is bent and deformed, so that carbon atoms do not need to be rearranged to adapt to external force, and the structure is stable. This stable lattice structure makes carbon atoms have excellent conductivity. When electrons in graphene move in orbit, they will not be scattered due to lattice defects or the introduction of foreign atoms. Because of the strong interatomic force, even if the surrounding carbon atoms collide at room temperature, the interference of electrons in graphene is very small.
3. Thermal conductivity:
Graphene has very high thermal conductivity and has been advocated for heat dissipation in recent years. Embedding graphene or several layers of graphene in the heat sink can greatly reduce the temperature of local hot spots. A study by the University of California shows that the thermal conductivity of graphene is better than that of carbon nanotubes. The high thermal conductivity graphene/carbon fiber flexible composite membrane developed by Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences has a controllable thickness of 10~200 microns and a room temperature thermal conductivity of 977 W/m? K, the tensile strength exceeds 15 MPa.
The thermal conductivity of ordinary carbon nanotubes can reach more than 3000W/mK, and the thermal conductivity of various metals is relatively high, such as silver, copper, gold, aluminum, etc., while the thermal conductivity of single-layer graphene can reach 5300W/mK, and even research shows that its thermal conductivity is as high as 6600 W/MK.
Graphene is expected to be used as a heat dissipation material for future VLSI due to its excellent thermal conductivity. Compared with pure graphene, graphene (RGOx) with relatively low thermal conductivity (0. 14 ~ 2.87 W/MK) was obtained by reducing graphite oxide. Its thermal conductivity is closely related to the oxidation degree of graphite oxide, because RGOx flakes are still oxidized even after thermal reduction treatment. Thermal conductivity may be related to defects such as residual chemical functional groups and damage of carbon six-membered rings. The oxidation of chemical structure leads to lattice defects and hinders heat conduction.
4. Mechanical characteristics
Graphene is the strongest substance known to mankind, harder than diamond and stronger than the best steel in the world 100 times. Physicists at Columbia University have conducted a comprehensive study on the mechanical properties of graphene. During the experiment, they selected some graphene particles with the diameter of 10-20 microns as the research object. The researchers first placed these graphene samples on a thin crystal plate with holes drilled on the surface, and the diameters of these holes ranged from 1 to 1.5 microns. After that, they used a probe made of diamond to put pressure on the graphene placed on the holes to test their endurance.
5, chemical properties:
At present, our understanding of graphene chemistry is that graphene can adsorb and desorb various atoms and molecules similar to graphite surface. From the point of view of surface chemistry, the properties of graphene are similar to those of graphite, which can be used to infer the properties of graphene. Graphene chemistry may have many potential applications. However, in order to get widespread attention to the chemical properties of graphene, we must overcome an obstacle and lack samples suitable for traditional chemical methods.