Carbon is one of the most common natural elements, carbon compounds bond and structure is extremely rich, expanded graphite is a kind of new carbon material. In early 1860s, Brodie natural graphite with sulfuric acid and nitric acid and other chemical reagents were found after heating, expanded graphite, but its application in only after death the beginning. Since then, many countries have launched the expansion of research and development of graphite, made a major scientific breakthrough. Expanded graphite is a kind of porous material like prepared from natural flake graphite, so called graphite. Natural flake graphite is a layered crystal, each layer of carbon atoms. With a strong covalent bond formed macromolecular reticular plane, and between the layers with weak binding force in Van Edward, a strong oxidizing agent under the action of mesh plane Molecules into plane macromolecules with positive charge, resulting in a polar H2SO4 molecule and hydrogen sulfate and other negative ions of expandable graphite formed into the graphite layer, also called graphite intercalation compounds (graphite, intercalation compounds, G ICs). Due to the expansion process, formed a unique network hole, than the large surface area, high activity and produced fresh surface
The expanded graphite pore developed mostly in large pores, so easy to absorb large molecules, the resistance to oxidation and corrosion. In less than 450 degrees Celsius in air oxidation; in addition, concentrated nitric acid, aqua regia fuming sulfuric acid and high temperature, a few potassium permanganate strong oxidizing agent, corrosion resistance the radiation resistance. Long term exposure can withstand the neutron ray, beta ray and gamma ray and other radioactive rays without decomposition, deformation, aging; the expanded graphite has thermal conductivity resistance, good self lubricity, impermeability, high and low temperature resistance, flexibility, resilience and excellent properties
