Sequentially compressive and intrusive mechanisms in mercury porosimetry of carbon blacks

The mechanism of mercury penetration in two different commercial carbon bla cks is studied. We show that the volume variation measured by mercury poros imetry in these systems is due to three successive mechanisms, which occur as the pressure increases: (1) mercury invasion of voids between macroscopi c grains, (2) compaction and elastic compression of macroscopic grains, (3) intrusion in the voids of aggregates formed by primary particles. The cumu lative surface calculated by the Rootare-Prenzlow equation (S-RP) in the in trusion part and the BET surface area measured by nitrogen adsorption (S-BE T) are compared. (C) 1999 Academic Press.