Expanded graphite sheet is a new, functional carbon material. It is a loose, porous, worm-like substance. They make it by intercalating, washing, drying, and high-temperature expanding natural graphite flakes.
EG has unique features not found in natural graphite. They are softness, compressibility, resilience, adsorption, environmental compatibility, biocompatibility, and radiation resistance.
Natural graphite has excellent properties. It resists heat, cold, corrosion, and it self-lubricates.
In the 1860s, Brodie discovered expanded graphite. He heated natural graphite with chemical reagents, like sulfuric and nitric acids. But its application did not start until a hundred years later. Since then, many countries have researched and developed expanded graphite. They have achieved significant breakthroughs in science and technology.
At high temperatures, expanded graphite sheets can expand by 150 to 300 times in a moment. It changes from flake-like to worm-like. Its structure becomes loose, porous, and curved. It has a larger surface area, higher energy, and stronger adsorption than flake graphite. The worm-like graphite can interlock. This makes it soft, resilient, and plastic.
