Chapter 9 Sorbents

TL;DR: In this article, it is shown that sharp boundaries among single types of phases (gas, liquid, and adsorbent) are removed, as is well known from chromatographic practice, and a continuous transition from gases up to solid substances does indeed exist.

Abstract: Publisher Summary The choice of the mobile and stationary phases is determined by experience in the appropriate field of application, and it is usually limited to several well-established systems Therefore, it can be useful to consider the range of substances that may fulfill the function of the solvent or the sorbent and attempt to classify them more rationally based on their physical nature and function during chromatographic sorption By applying such approach, it can be seen that sharp boundaries among single types of phases(gas, liquid, and adsorbent) are removed, as is well known from chromatographic practice, and a continuous transition from gases up to solid substances does indeed exist A sufficiently compressed gas in the supercritical region already has the properties of a liquid, and this applies even more to a completely liquefied gas A similar continuous transition also occurs in the construction of porous materials from strictly geometrically regular networks of porous crystals to substances with random porosity