Activated carbon is a kind of microcrystalline carbon material which is mainly made of carbon-containing materials with black appearance, developed internal pore structure, large specific surface area and strong adsorption capacity. Activated carbon material has a large number of invisible microporous, 1 gram of activated carbon material in the microporous, will unfold its surface area can be as high as 800-1500 square meters, special purpose higher. In other words, in an activated carbon particle the size of a grain of rice, the internal surface area of the micropores may be equivalent to the size of a living room. It is these highly developed pore structures, such as human capillaries, that give activated carbon its excellent adsorption properties.

2. The force of adsorption between molecules

It is also called "Vandewar gravity". Although the speed of molecular movement is affected by temperature and material, it is always moving in the microenvironment. Due to the force of attraction between molecules, when a molecule is captured by the activated carbon pores into the activated carbon pores, due to the reason of attraction between molecules, it will lead to more molecules to be attracted until the activated carbon pores are filled.