Numerical study of multilayer adsorption on fractal surfaces

We report a numerical study of van der Waals adsoprtion and capillary condensation effects on self-similar fractal surfaces. An assembly of uncoupled spherical pores with a power-law distributin of radii is used to model fractal surfaces with adjustable dimensions. We find that the commonly used fractal Frankel-Halsey-Hill equation systematically fails to give the correct dimension due to crossover effects, consistent with the findings of recent experiments. The effects of pore coupling and curvature dependent surface tension were also studied.Comment: 11 pages, 3 figure

Fractal Analysis of Mercury Porosimetry Data in the Framework of the Thermodynamic Method

The thermodynamic method for fractal analysis is applied to mercury intrusion data. The results for representative commercial carbon black samples and a series of resorcinol-formaldehyde (RF) freeze-dried gels for different values of the molar ratio of resorcinol (R) to catalyst (C) are discussed in relation with the type of behavior exhibited by the samples during mercury porosimetry measurements. The obtained surface fractal dimensions are compared with those derived previously from the small-angle X ray scattering (SAXS) and the nitrogen adsorption. Copyright 1999 Academic Press