Micropore structures of charcoal adsorbents. 1. A general characterization of micro- and supermicropores in the fissure model

Abstract

1. Discussion is given of a general scheme for the formation and development of micro and supermicropore systems in the activation of carbonized organic materials. This scheme is used as a basis for pore form characterization. 2. Discussion is also given of the various experimentally determined parameters for this model: the diameters of the carbon crystallites and the gyration radii of the pores as determined from x-ray scattering at both large and small angles, and the characteristic energy of adsorption of the standard vapor (benzene) as calculated from a single adsorption isotherm through the theory of bulk micropore filling. 3. The earlier x-ray and adsorptional studies on charcoal adsorbents with differing micropore structures have been generalized. To a good degree of approximation, the gyration radii of the micro- and supermicropores are inversely proportional to the characteristic energy of adsorption. It has been shown that the relation between the characteristic micro-and supermicropore radii and the characteristic adsorption energy gives a basis for pore classification. 4. The model adopted here has been used to calculate parameter values for micro- and supermicropores, the latter considered as plane fissures formed in the carbon crystals under partial or total burn off of the individual layers of carbon atoms or crystals.