The macroscopic laws of capillarity such as Laplace, Kelvin, and Young-Dupre equations are not adequate when applied to fluids confined by nanostructured particles and porous materials. In this talk, we discuss applications of MC simulations, density functional theory, and empirical models to study capillary condensation hysteresis with the example of nitrogen and argon adsorption in cylindrical pores of highly ordered MCM-41 materials. Our objectives are to understand the basic mechanisms of the dispersion process and to interpret the structural characteristics of the porous media. We want to put in evidence the presence of heterogeneities and, to analyze the interaction between the components of the fluid and the porous media. In particular, we want to understand which is the influence of the rheology on the dispersion phenomena.
Radioactive technique allows to have additional local information unavailable with usual techniques.
Finally, when we considered the influence of rheology, we observed an increase of the dispersion as a function of the rheological index. Percolation Effects on Adsorptio n -Desorption Hysteresis R. H. L pez , A. M. Vidales, and G. Zgrablich . The behavior of the threshold pressure for the evaporation process, as a function of the separation between the site and bond distributions and their dispersions, suggests a method to determine them from experimental adsorptio n -desorption hysteresis curves. The effects of connectivity and correlation among the porous elements are analyzed. The combination of these two effects affects strongly the shape of the hysteresis loops produced by the sorption of N 2 therein the structures.