Fig. 6
Critical fluid film thickness. Ratio 2t/D according to the pore diameter D where t is the thickness of a N2 layer at a siliceous pore wall when the pore fills in. The line is a prediction from the minimization of the grand potential Ω taking into account the dependence of the Derjaguin disjoining pressure term with the thickness t. Symbols are experimental values for zeosils (open symbol, effective thickness) and for silica mesopores (filled symbol, condensed film thickness)29. The insets illustrate the ratio of the film thickness t to the pore size D for both the small (left) and large (right) nanopore domains. In both cases, the blue spheres denote the adsorbed fluid molecules while the gray and blue shaded areas indicate the adsorbed film and solid matrix, respectively
