P. Nikitas, A SIMPLE STATISTICAL-MECHANICAL APPROACH FOR STUDYING MULTILAYER ADSORPTION - EXTENSIONS OF THE BET ADSORPTION-ISOTHERM, Journal of physical chemistry, 100(37), 1996, pp. 15247-15254
A new statistical mechanical approach for studying multilayer adsorpti
on phenomena is presented. It is shown that a multilayer adsorbed film
can be treated as a multicomponent monolayer, the equilibrium equatio
ns of which are determined from the adsorption process and the process
es which form the constituents of the monolayer. The derivation of the
equilibrium equations is extremely simple and allows the extension of
the BET isotherm to complicated systems. In this respect, the effect
of the short-range lateral interactions on the properties of the BET i
sotherm is examined. In addition, effects coming from multisite occupa
ncy with or without lateral interactions and from the energetic hetero
geneity of the adsorbent surface affecting only the first or the first
and the second sublayer are also taken into account and discussed.