A Hierarchical Structural Model for the Interpretation of Mercury Porosimetry and Nitrogen Sorption

The Influence of Mercury Contact Angle, Surface Tension, and Retraction Mechanism on the Interpretation of Mercury Porosimetry Data

“…The theory is described in great detail elsewhere (24)(25)(26), and therefore it will not be repeated here. In earlier work (23,27) the ratio of the lattice sizes obtained for whole and fragmented samples was of the order of ∼1, despite the fact that the absolute values of lattice sizes obtained were <20, and the whole and powder particle sizes differed by a factor of ∼100. As explained in previous work (23,27), the similarity in the lattice sizes obtained for whole and fragmented samples would seem to suggest that both may be considered to be so-called "large lattices" in their percolation behavior.…”

“…In earlier work (23,27) the ratio of the lattice sizes obtained for whole and fragmented samples was of the order of ∼1, despite the fact that the absolute values of lattice sizes obtained were <20, and the whole and powder particle sizes differed by a factor of ∼100. As explained in previous work (23,27), the similarity in the lattice sizes obtained for whole and fragmented samples would seem to suggest that both may be considered to be so-called "large lattices" in their percolation behavior. This is because in percolation processes on random lattices, as the lattice size becomes large (generally >60 bond lengths (26)), the percolation properties tend toward those of an infinite random lattice and become more, or less, independent of lattice size.…”

“…However, the actual absolute values of lattice sizes obtained suggested that the pore networks in the samples were very small. In earlier work (23,27), this seemingly paradoxical result was interpreted to mean that spatial correlations in pore size were present over large length scales. The large regions of similar pore size might behave analogously to a single pore bond in percolation processes.…”

Pore‐structure analysis by using nitrogen sorption and mercury intrusion data

“…In particular, except for a simple pore-size distribution, information concerning the uniformity of the pore system, pore-size correlations, and pore-network connectivity would be helpful in the quality control of any industrially produced porous material. However, in spite of the high degree of sophistication that has been embedded into several approaches of pore-structure analysis (Mason, 1988;Liu et al, 1992;Rigby, 2000), no systematic procedure has yet been developed to combine Hg porosimetry with N 2 sorption data in such a consistent way that unique geometrical and topological properties of the pore structure are derived.…”

“…Nevertheless, little attention has been paid on the characterization of the structure of mesoporous materials, in terms of pore network models, by deconvolving simultaneously the N 2 adsorption/desorption isotherms and Hg intrusion/retraction curves and producing only one set of geometrical and topological parameters. For example, data from N 2 adsorption and NMR were taken into account for by the interpretation of Hg porosimetry data of catalysts in terms of the parameters of a multiscale pore structure model (Rigby, 2000). NMR images were employed to identify heterogeneities in voidage and pore sizes over a broad range of length scales (Gladden et al, 1995), whereas the use of multiscale pore networks was proved very efficient in the interpretation of Hg porosimetry data for materials exhibiting a broad pore-size distribution (Tsakiroglou and Payatakes, 1993;Xu et al, 1997).…”