CORRELATION BETWEEN SURFACE-AREAS AND MICROPORE VOLUMES OF ACTIVATED CARBONS OBTAINED FROM PHYSICAL ADSORPTION AND IMMERSION CALORIMETRY

The heats of immersion of a series of activated carbons with increasing porosity into a number of liquids with different molecular sizes (benzene, 2,2-dimethylbutane and isooctane) have been measured at 303 K. The experimental values have been used to calculate the corresponding surface areas (using a nonporous carbon (V3G) as reference) and micropore volumes. These parameters have been compared with those obtained from physical adsorption of N-2 at 77 K and of the same hydrocarbons at 298 K: A good correlation has been found between the values obtained from both techniques provided no lack of accessibility of the liquid or vapor to the whole microporous structure of the carbon is present.