Some Basics about Graphene

Graphene first appeared in the laboratory in 2004. At that time, two British scientists, Andre Geim and Prof Kostya Novoselov, discovered that they could get thinner and thinner graphite flakes in a very simple way. They peeled the graphite flakes from the graphite, and then glued the two sides of the flakes to a special tape. When the tape was peeled off, the graphite flakes were divided in two. Keep doing this, the sheets get thinner and thinner, and in the end, they get a sheet made of just one layer of carbon atoms, which is graphene. The two scientists won the Nobel Prize in 2010. Graphene is by far the thinnest (3 million graphene sheets are only 1 mm thick) and the strongest material, and it is also the material with the strongest electrical and thermal conductivity known to people. It has extraordinary hardness and flexibility. It can be widely used in the manufacture of various items such as touch screens, solar cells, and composite materials such as carbon fiber. Graphene is a good barrier material. Graphene is a very dense material, because the distance between atoms is very close, only 0.142 nm, so its bonds are very short. That is to say, even molecules and atoms as small as hydrogen and helium cannot pass through it. Therefore, it is a good barrier material, with a specific surface area of 2630 square meters per gram, which is very large. Hence, graphene is used to make some filtering materials to separate different gases or liquids, such as the separation of salt in seawater, the separation of water and gas, the separation of oxygen and nitrogen in the air, or the separation of various volatile organic compounds. The mechanical tensile strength of graphene is one hundred times that of steel.rnThe mechanical tensile strength of graphene reaches 130GPa, which is equivalent to one hundred times that of steel. According to theoretical calculations, if the effective connection thickness of graphene can reach one millimeter, it can even support the weight of an adult elephant. The reason why graphene's mechanical properties are so strong is because there are three "neighbors" around each carbon, and the carbon bonds formed by these three "neighbors" are very short and very strong. Graphene has excellent electrical conductivity.rnIn theory, graphene's electrical properties are also excellent, and the electron mobility can reach 200,000 cm2/Vs, which is one hundred times that of silicon. Electron mobility refers to how fast electrons can run in this material. The conductivity of a material is determined by two things, one is how fast electrons run in it, and the second is how many electrons run in it. The lattice structure endows graphene with excellent electrical conductivity. The electronic structure of graphene can be obtained by the nearest-neighbor tight-binding model. Each unit lattice of graphene has 2 carbon atoms. The effect of graphene on the human bodyrnFar-infrared wavesrnThe vibration frequency of far-infrared waves emitted by graphene is close to the vibration frequency of 6-14 microns of cells and molecules in the human body. Through molecular resonance in the body, heat energy is generated, and the heat energy is penetrated into the subcutaneous tissue, causing the temperature to rise, thereby promoting blood circulation and promoting metabolism. Helps improve sleeprnGraphene releases far-infrared rays to penetrate the eye skin, soothe eye muscles, relieve fatigue, and help relax your mind and body into sleep. Makes body maintain healthyrnGraphene can release far-infrared rays, quickly promote blood circulation in limbs and joints, activate tissue cell repair, promote metabolism and eliminate toxins, and restore the body to a healthy state. Improves immunityrnThe far-infrared rays released by graphene can enhance human immunity and allow the body to enhance its self-healing function, promote endocrine stability and reduce the risk of various diseases invading the body.