PHYSISORPTION OF GASES BY CARBON-BLACKS

Carbon blacks have been featured as model adsorbents in many fundamental investigations of gas adsorption. In particular, the use of graphitized blacks has led to important advances in the understanding of adsorbent-adsorbate interactions and the interpretation of adsorption data. However, in the light of recent work it is necessary to reassess the significance of earlier isotherm and hear of adsorption measurements. Thus, not all carbon blacks behave as nonporous adsorbents, and in some cases (for example, samples of Spheron 6) there is evidence of slight microporosity. Furthermore, the graphitized sur face generally exhibits some degree of energetic heterogeneity. No current theory is able to provide a general mathematical description of physisorption isotherms, and various empirical procedures are used for the analysis of experimental data. Caution must be exercised in the interpretation of derived values of surface area and porosity.