Chi Representation of Standard Nitrogen, Argon, and Oxygen Adsorption Curves

The representation of the standard curves such as the α-s curve, the t-curve, and others as chi adsorption curves was examined. Even if the chi theory, which is based upon a quantum mechanical-statistical thermodynamic derivation, is rejected, the empirical fit to the chi theory transformation yields a useful and accurate representation of most standard curves. Where available, the original data were used to generate the standard curve in the chi transformation. Most may be expressed to within 1% accuracy as a straight line on the chi plot over the entire physisorption range. A few others require two additional parameters, related to a fractal analysis of mesoporosity, to yield this precision. The advantage of this technique is a more precise and a mathematically simpler method as opposed to tabulated standard curves.