Carbon molecular sieves are composed primarily of carbon atoms and feature a two- or three-dimensional network of pores capable of adsorbing substances of varying sizes and properties. Based on pore size, they are classified into three types: micropores, mesopores, and macropores. Micropores have diameters smaller than 2 nm, mesopores range from 2 to 50 nm, and macropores exceed 50 nm. Micropores and mesopores are the most common pore structures found in carbon molecular sieves.
The microporous structure is formed by carbon atoms, creating voids comparable in size to many molecules. Consequently, these micropores can be utilized to separate molecules within liquid or gaseous mixtures, thereby enabling separation and purification. For instance, microporous structures can be used to separate large molecules from small ones or to distinguish between isomers.
The mesoporous structure consists of larger voids formed by interconnected carbon atoms. As the pore size is significantly larger than that of micropores, these structures are suitable for separating large molecules-such as proteins or polypeptides of differing molecular sizes.