MODIFICATION OF THE STRUCTURE OF AN ACTIVE-CARBON BY HEAT-TREATMENT

A series of active carbons was prepared by combination of activation (by steam, at 1173 K) and by heat treatment (at 1523 K, 2 h under nitrogen) and the structures of the samples were investigated by gas adsorption (nitrogen adsorption isotherms) and by X-ray scattering. An agreement is observed between the average chord length of segments in the solid phase measured by SAXS and the average micropore size determined by gas adsorption, suggesting that the diameters of micropores formed during the activation and the heat treatment have nearly the same size as the crystallites.