F. Ehrburgerdolle et al., USE OF N-2 AR AND CO2 ADSORPTION FOR THE DETERMINATION OF MICROPOROSITY AND SURFACE FRACTAL DIMENSION OF CARBON-BLACKS AND SILICAS, Pure and applied chemistry, 65(10), 1993, pp. 2223-2230
The microporosity of silicas and carbon blacks is characterized by usi
ng the Dubinin-Radushkevitch (D-R) equation. It is shown that the shap
e of the D-R lines corresponding to the adsorption of N2 and Ar on sil
icas are very different from that obtained on carbon blacks. It is exp
lained by differences in the accessibility of the micropores for small
molecules at low temperature. The Ar and N2 BET surface areas are det
ermined and the value of the molecular area of N2 on silicas is discus
sed. The surface fractal dimensions of the two types of adsorbents are
determined by means of the FHH fractal equation from the N2 adsorptio
n isotherm above the monolayer coverage.